# Patent

## Title
Apparatus and method for transmitting/receiving pilot signal in communication system using OFDM scheme

## Abstract

Disclosed is a method for transmitting a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier. The method includes receiving a cell identifier, and generating a block code corresponding to the cell identifier using a predetermined block code generator matrix, and generating a first part sequence using the block code; selecting a second part sequence in accordance with the cell identifier; generating a reference signal of a frequency domain using the first part sequence and the second part sequence; converting the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform operation and transmitting the reference signal of the time domain in a predetermined reference signal transmission interval.

## Background
PRIORITY
This application claims priority to an application entitled “Apparatus And Method For Transmitting/Receiving Pilot Signal In Communication System Using OFDM Scheme” filed in the Korean Industrial Property Office on Jul. 2, 2004 and assigned Ser. No. 2004-51468 and on Aug. 26, 2004 and assigned Ser. No. 2004-69408, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a communication system using an Orthogonal Frequency Division Multiplexing (OFDM) scheme, and more particularly to an apparatus and a method for transmitting/receiving pilot signals for identifying base stations and sectors.
2. Description of the Related Art
In a 4th generation (4G) communication system, which is the next generation communication system, research has been actively pursued to provide users with services having various qualities of service (QoS) and supporting a high transmission speed. Currently, in the 4G communication system, research has been actively pursued to support high speed services while ensuring mobility and QoS in a Broadband Wireless Access (BWA) communication system such as a wireless Local Area Network (LAN) and a Metropolitan Area Network (MAN) system.
In the 4G communication system, known to be useful for high speed data transmission in wire or wireless channels, the OFDM scheme is now actively being researched. The OFDM scheme, which transmits data using multiple carriers, is a special type of a Multiple Carrier Modulation (MCM) scheme in which a serial symbol sequence is converted into parallel symbol sequences and the parallel symbol sequences are modulated with a plurality of mutually orthogonal sub-carriers before being transmitted.
In order to provide wireless multimedia service of high speed and high quality, the 4G communication system requires a wideband spectrum resource. However, when the wideband spectrum resource is used, the influence of fading on the wireless transmission paths due to multi-path propagation becomes severe, and the frequency selective fading has an influence on the transmission frequency bands. Therefore, for high speed wireless multimedia service, the OFDM scheme is now used more frequently than the Code Division Multiple Access (CDMA) scheme in the 4G communication system, since the OFDM scheme is more robust against the frequency selective fading and is thus more advantageous than the CDMA scheme.
Now, operations of a transmitter and a receiver in a communication system using the OFDM scheme (“hereinafter, the OFDM communication system”) will be briefly discussed.
In the transmitter of the OFDM communication system, input data is modulated into sub-carrier signals by a scrambler, an encoder and an interleaver. Here, the transmitter provides a variety of variable data rates, based on which the coding rate, the interleaving size and the modulation scheme are determined. Usually, the encoder uses coding rates such as 1⁄2, 3⁄4, etc., and the interleaving size for preventing burst error is determined according to the Number of Coded Bits Per OFDM Symbol (NCBPS). As the modulation scheme, a Quadrature Phase Shift Keying (QPSK) scheme, an 8-aryPhase Shift Keying (8PSK) scheme, a 16-ary Quadrature Amplitude Modulation (16QAM) scheme, or a 64-ary Quadrature Amplitude Modulation (64QAM) scheme may be used, according to the data rates.
Meanwhile, a predetermined number of the modulated sub-carrier signals are added to a predetermined number of pilot sub-carrier signals, and an Inverse Fast Fourier Transform (IFFT) unit performs IFFT for the added signals, thereby generating an OFDM symbol. Then, guard intervals are inserted into the OFDM symbol in order to eliminate the inter-symbol interference (ISI) in the multi-path channel environment. The OFDM symbol containing the guard intervals is finally input to a Radio Frequency (RF) processor through a symbol waveform generator. Then, the RF processor processes the input signal and transmits the processed signal over the air.
Here, the guard interval is inserted in order to eliminate interference between OFDM symbols transmitted in the previous OFDM symbol time and OFDM symbols to be transmitted in the current OFDM symbol time. Therefore, a cyclic prefix method or a cyclic postfix method is usually used in inserting the guard interval. In the cyclic prefix method, a predetermined number of last bits of an OFDM symbol in the time domain are copied and inserted into an effective OFDM symbol. In the cyclic postfix method, a predetermined number of initial bits of an OFDM symbol in the time domain are copied and inserted into an effective OFDM symbol.
The receiver of the OFDM communication system, corresponding to the transmitter as described above, performs a process in reverse to the process in the transmitter together with an additional synchronization step.
To be more specific, first, frequency offset estimation and symbol offset estimation are performed using a training symbol set in advance for a received OFDM symbol. Then, a data symbol obtained by eliminating guard intervals from the OFDM symbol is restored to a predetermined number of sub-carrier signals containing a predetermined number of pilot sub-carriers added thereto by a Fast Fourier Transform (FFT) unit. Further, in order to overcome a path delay in an actual wireless channel, an equalizer estimates channel condition for the received channel signal, thereby eliminating signal distortion in the actual wireless channel from the received channel signal. The channel-estimated data from the equalizer is transformed into a bit stream which then passes through a de-interleaver. Thereafter, the bit stream passes through a decoder and descrambler for error correction and is then output as final data.
In the OFDM communication system as described above, a transmitter (for example, a Base Station (BS)) transmits pilot sub-carrier signals to a receiver (for example, a Mobile Station (MS)). The BS simultaneously transmits data sub-carrier signals together with the pilot sub-carrier signals. The MS can perform synchronization acquisition, channel estimation and BS identification by receiving the pilot sub-carrier signals. That is, the pilot sub-carrier signal is a kind of reference sub-carrier signal and serves as a kind of training sequence, thereby enabling channel estimation between the transmitter and the receiver. Moreover, an MS can identify by using the pilot sub-carrier signal a BS to which the MS belongs. The locations for the pilot sub-carrier signals have been agreed in advance by a protocol between the transmitter and the receiver. As a result, the pilot sub-carrier signals operate as kinds of reference signals.
A process will now be described in which an MS identifies, by using the pilot sub-carrier, and signals a BS to which the MS belongs.
First, the BS transmits the pilot sub-carrier signals with a relatively higher transmit power than that for the data sub-carrier signals such that the pilot sub-carrier signals can reach the cell boundary with a particular pattern (specifically, a pilot pattern). The reason why the BS transmits the pilot sub-carrier signals with a relatively high transmit power such that the pilot sub-carrier signals can reach the cell boundary with a particular pilot pattern will now be described.
First, the MS does not have any information about the BS to which the MS currently belongs when the MS enters a cell. In order to detect the BS to which the MS belongs, the MS must receive the pilot sub-carrier signals. Therefore, the BS transmits the pilot sub-carrier signals having a particular pilot pattern with a relatively high transmit power, in order to enable the MS to detect the BS to which the MS belongs.
Meanwhile, the pilot pattern implies a pattern generated by the pilot sub-carrier signals transmitted by the BS. That is, the pilot pattern is generated by the slope of the pilot sub-carrier signals and the start point at which the pilot sub-carrier signals begin to be transmitted. Therefore, the OFDM communication system must be designed such that each BS in the OFDM communication system has a specific pilot pattern for its identification. Further, coherence bandwidth and coherence time must be taken into account in generating the pilot pattern. Now, coherence bandwidth and coherence time will be discussed.
The coherence bandwidth signifies a maximum bandwidth on an assumption that a channel is constant in a frequency domain. The coherence time signifies a maximum time on an assumption that a channel is constant in a time domain. Therefore, it can be assumed that the channel is constant within the coherence bandwidth and coherence time. As a result, transmission of a single pilot sub-carrier signal within the coherence bandwidth and during the coherence time is sufficient for synchronization acquisition, channel estimation and BS identification.
Such transmission of a single pilot sub-carrier signal within the coherence bandwidth and during the coherence time can maximize transmission of data sub-carrier signals, thereby improving performance of the entire system. Therefore, it can be said that the coherence bandwidth is a maximum frequency interval with which the pilot sub-carrier signals are transmitted and the coherence time is a maximum time interval with which the pilot channel signals are transmitted, that is, a maximum OFDM symbol time interval.
Meanwhile, the number of BSs included in the OFDM communication system depends on the size of the OFDM communication system. Usually, a larger OFDM communication system includes more BSs. Therefore, in order to identify each of the BSs in the OFDM communication system, the number of the pilot patterns having different slopes and different start points must be equal to or greater than the number of the BSs included in the OFDM communication system. However, in order to transmit the pilot sub-carrier signals in the time-frequency domain of the OFDM communication system, the coherence bandwidth and the coherence time must be taken into consideration as described above. When the coherence bandwidth and the coherence time is taken into consideration, there is a limit to the number of the pilot patterns having different slopes and different start points. In contrast, when the pilot pattern is generated without considering the coherence bandwidth and the coherence time, pilot sub-carrier signals in pilot patterns representing different BSs get mixed up, so that it becomes impossible to identify the BSs by using the pilot patterns.
Locations at which pilot subcarriers are transmitted according to the pilot patterns in a typical OFDM communication system using one pilot sub-channel will now be discussed with reference to FIG. 1.
FIG. 1 is a graph schematically illustrating locations at which pilot subcarriers are transmitted according to the pilot patterns in a typical OFDM communication system using one pilot sub-channel.
Referring to FIG. 1, all slopes which can be generated by the pilot patterns and the number of the slopes (that is, the slopes according to the pilot sub-carrier signal transmission and the number of the slopes) are limited by the coherence bandwidth 100 and the coherence time 110. When the coherence bandwidth 100 is 6 and the coherence time 110 is 1, if the slope of the pilot pattern is an integer, six slopes from the slope s=0 (101) to the slope s=5 (106) can be generated as the slope of the pilot pattern. That is, under the conditions described above, the slope of the pilot pattern consists of integers from 0 to 5.
Here, the fact that six slopes of the pilot patterns can be generated implies that six BSs can be identified by using the pilot patterns in the OFDM communication system satisfying the conditions described above. A hatched circle 107 in FIG. 1 represents another pilot sub-carrier signal spaced with the coherence bandwidth 100 away from the first pilot sub-carrier signal. As a result, the slopes of the pilot patterns are limited by the coherence bandwidth 100.
As described above, the number of the pilot patterns used in order to identify BSs in the OFDM communication system is limited by the coherence bandwidth and the coherence time. Therefore, the limitation in the number of the pilot patterns which can be generated limits the number of identifiable BSs in the OFDM communication system.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide an apparatus and a method for transmitting/receiving pilot signals for identifying base stations and sectors in an OFDM communication system.
It is another object of the present invention to provide an apparatus and a method for transmitting/receiving pilot signals in an OFDM communication system, which can minimize interference between the pilot signals.
It is another object of the present invention to provide an apparatus and a method for transmitting/receiving pilot signals each having a variable length in an OFDM communication system.
It is another object of the present invention to provide an apparatus and a method for transmitting/receiving pilot signals by using block codes generated by means of a Walsh basis and mask sequences in an OFDM communication system.
In order to accomplish this object, there is provided a method for transmitting a reference signal for identification of each cell in a communication system including a plurality of cells, each of which is identified by a cell identifier, the method including the steps of receiving a cell identifier, and generating a block code corresponding to the cell identifier using a predetermined a block code generator matrix, and then generating a first part sequence using the block code; selecting a second part sequence in accordance with the cell identifier; generating a reference signal of a frequency domain using the first part sequence and the second part sequence; converting the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform (IFFT) operation and then transmitting the reference signal of the time domain in a predetermined reference signal transmission interval.
In accordance with another aspect of the present invention, there is also provided a method for transmitting a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, and an entire frequency band of the communication system including a sub-carrier bands, the method including the steps of in response to input of the cell identifier, generating a block code corresponding to the cell identifier using a predetermined block code generator matrix; generating a first part sequence by interleaving the block code according to a predetermined interleaving scheme and performing an exclusive OR operation on the interleaved block code; selecting a second part sequence corresponding to the cell identifier and from among predetermined sequences considering Peak-to-Average Power Ratio(PAPR) reduction; generating a reference signal of a frequency domain by using the first part sequence and the second part sequence; converting the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform (IFFT) operation and then transmitting the reference signal of the time domain in a predetermined reference signal transmission interval.
In accordance with another aspect of the present invention, there is also provided a method for receiving a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, and an entire frequency band of the communication system including a sub-carrier bands, the method including the steps of extracting the reference signal from a received signal which has been converted through a Fast Fourier Transform (FFT) operation; dividing the reference signal into a predetermined number of intervals and performing an exclusive OR (XOR) operation on the divided intervals; deinterleaving the XOR-processed signal according to a predetermined deinterleaving scheme; dividing the deinterleaved signal into sub-block signals in accordance with a predetermined block code generator matrix; performing an Inverse Fast Hadamard Transform (IFHT) using mask sequences generated according to control of each of the sub-block signals; generating a combined signal by combining the IFHT-processed signals for each of the sub-block signals; and determining a cell identifier corresponding to a block code having a maximum correlation value from among the combined signals as a final cell identifier.
In accordance with another aspect of the present invention, there is also provided a method for transmitting a reference signal for identification of each cell through at least one transmit antenna in a communication system including a plurality of cells each of which is identified by a cell identifier, and an entire frequency band of the communication system including a sub-carrier bands, the method including the steps of receiving a cell identifier, generating a block code corresponding to the cell identifier by using a predetermined block code generator matrix, selecting a Walsh code corresponding to the cell identifier from among predetermined Walsh codes, and repeating the selected Walsh code a predetermined number of times; interleaving the block code according to a predetermined interleaving scheme and performing an exclusive OR operation on the interleaved block code and the repeated Walsh code, thereby generating a first part sequence; selecting a second part sequence corresponding to the cell identifier from among predetermined sequences; generating a reference signal of a frequency domain by using the first part sequence and the second part sequence; and converting the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform (IFFT) operation and then transmitting the reference signal of the time domain in a predetermined reference signal transmission interval.
In accordance with another aspect of the present invention, there is also provided an apparatus for transmitting a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, the apparatus including a reference signal generator which, in response to input of the cell identifier, generates a block code corresponding to the cell identifier by using a predetermined block code generator matrix, generates a first part sequence by using the block code, selects a second part sequence in accordance with the cell identifier, and generates a reference signal of a frequency domain by using the first part sequence and the second part sequence; and a transmitter for converting the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform and operation and then transmitting the reference signal of the time domain over a reference signal transmission interval.
In accordance with another aspect of the present invention, there is also provided an apparatus for transmitting a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, and an entire frequency band of the communication system including a sub-carrier bands, the apparatus including a block code encoder which, in response to input of the cell identifier, generates a block code corresponding to the cell identifier by using a predetermined block code generator matrix; an interleaver for interleaving the block code according to a predetermined interleaving scheme; an adder for performing an exclusive OR operation on the interleaved block code, thereby generating a first part sequence; a combiner for generating a reference signal of a frequency domain by using the first part sequence and a second part sequence which is selected corresponding to the cell identifier from among predetermined sequences; and a transmitter for converting the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform(IFFT), and operation and then transmitting the reference signal of the time domain over a reference signal transmission interval.
In accordance with another aspect of the present invention, there is also provided an apparatus for receiving a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, and an entire frequency band of the communication system including a sub-carrier bands, the apparatus including a Fast Fourier Transform (FFT) unit for performing an FFT operation on a received signal; a reference signal extractor for extracting the reference signal from the FFT-processed signal; an adder for dividing the reference signal into a predetermined number of intervals and performing an exclusive OR (XOR) operation on the divided intervals; a deinterleaver for deinterleaving the XOR-processed signal according to a predetermined deinterleaving scheme; a sub-block divider for dividing the deinterleaved signal into sub-block signals in accordance with a predetermined block code generator matrix; a block code decoder for performing an Inverse Fast Hadamard Transform (IFHT) using mask sequences generated according to control of each of the sub-block signals; a combiner for generating a combined signal by combining the IFHT-processed signals for each of the sub-block signals; and a comparison selector for determining a cell identifier corresponding to a block code having a maximum correlation value from among the combined signals as a final cell identifier.



BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a graph schematically illustrating all slopes which can be generated by the pilot patterns in a typical OFDM communication system;
FIG. 2 is a block diagram illustrating an internal structure of a pilot signal generator of an OFDM communication system according to an embodiment of the present invention;
FIG. 3 is a block diagram illustrating an internal structure of a transmitter of an OFDM communication system according to an embodiment of the present invention;
FIG. 4 is a block diagram illustrating an internal structure of a receiver of an OFDM communication system according to an embodiment of the present invention;
FIG. 5 is a block diagram illustrating an internal structure of a cell ID/sector ID detector of FIG. 4;
FIG. 6 is a flowchart of an operation process of a transmitter in an OFDM communication system according to an embodiment of the present invention;
FIG. 7 is a flowchart of an operation process of a receiver in an OFDM communication system according to an embodiment of the present invention;
FIG. 8 is a schematic view for illustrating a mapping relation between sub-carriers and pilot symbols when an IFFT is performed in an OFDM communication system according to an embodiment of the present invention;
FIG. 9 illustrates a frame structure of a pilot symbol in the time domain of an OFDM communication system according to an embodiment of the present invention; and
FIG. 10 illustrates a structure of a pilot symbol in the frequency domain of an OFDM communication system according to an embodiment of the present invention.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention unclear.
The present invention provides an apparatus and a method for transmitting/receiving pilot signals for identifying base stations and sectors in an OFDM communication system. In particular, the present invention provides an apparatus and a method for transmitting/receiving pilot signals through at least one antenna, which can minimize interference between the pilot signals in performing identification of base stations and sectors in an OFDM communication system.
FIG. 2 is a block diagram illustrating an internal structure of a pilot signal generator of an OFDM communication system according to an embodiment of the present invention.
Referring to FIG. 2, the pilot signal generator includes a block code encoder 201, an interleaver 203, a Walsh code repeater 205, an adder 207 and a combiner 209.
First, a cell identifier (ID), which is an ID for identifying a cell (i.e. BS), is input to the block code encoder 201. Upon receiving the cell ID, the block code encoder 201 generates a codeword (i.e. block code) corresponding to the cell ID from a generator matrix G (not shown) stored in advance in the block code encoder 201 and outputs the generated block code to the interleaver 203. The generator matrix G generates block codes corresponding to the cell IDs, which are clearly differentiable from each other. The generator matrix G will be described now with reference to Equation (1) below.




First, on an assumption that the generator matrix G has Nr rows and Nc columns, the length NG of the block code which can be generated by using the generator matrix G is equal to the number Nc of the columns of the generator matrix G. Further, the pilot symbols generated by the block code can identify a maximum number of (2Nr−1) cells. Each of the Nc columns includes a number of sub-blocks each having a length of Nc/a which is designed to be less than the coherence bandwidth of a channel. The a sub-blocks in each of the Nc columns include




  
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Walsh bases and n mask sequences. Here, the Walsh bases in the a sub-blocks are the same Walsh basis. The number n of the mask sequences is equal to





  
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In equation (1), mask(i) represents the i-th mask sequence. In the generator matrix G, the second sub-block is generated through an (n-1) time cyclic shift of the rows of the first sub-block, and the m-th sub-block is generated through an (n-j) time cyclic shift of the rows of the first sub-block in the same way. The cyclic shift is performed in such a way as to maximize the minimum distance of the block code generated by using the generator matrix G.

The interleaver 203 receives the signal output from the block code encoder 201, interleaves the signal according to a predetermined interleaving scheme and outputs the interleaved signal to the adder 207. The reason why the interleaver 207 interleaves the signal from the block code encoder 201 according to the predetermined interleaving scheme is that the Peak to Average Power Ratio (PAPR) of the pilot signal becomes high when the block code generated in the block code encoder 201 (i.e. the block code generated correspondingly to a specific cell ID) includes a frequently repeated numerical sequence of a specific pattern. In other words, the PAPR of the pilot signal of the OFDM system is reduced (i.e. the PARP characteristic is improved) by interleaving all block codes generated by the block code encoder 201.
Now, an internal structure of the interleaver 203 will be discussed.
First, the interleaver 203 includes a internal interleavers (not shown) which perform interleaving for the signals generated through the a sub-blocks of the generator matrix G, respectively. That is, the block code output from the block code encoder 201 is divided into a sub-codes which are interleaved in different ways by the a internal interleavers, respectively. Through the interleaving for each of the a sub-codes of the block code by the interleaver 203, the receiver can decode the information data corresponding to the block code transmitted from the transmitter, by using the Inverse Fast Hadamard Transform (IFHT) using the Walsh basis.
In the meantime, a sector ID (an ID for identifying a sector) is input to the Walsh code repeater 205. Upon receiving the sector ID, the Walsh code repeater 205 repeats a Walsh code corresponding to the sector ID a predetermined number of times and then outputs a signal, including the repeated Walsh code, to the adder 207.
In the present embodiment, it is assumed that the pilot symbol of the OFDM communication system has a length of Np, the block code generated by the block code encoder 201 has a length NG, and the Walsh code has a length of Nw. On this assumption, the Walsh code repeater 205 repeats NW/NG times the Walsh code corresponding to the sector ID and outputs the signal including the repeated Walsh code to the adder 207. Here, the length of the signal output from the Walsh code repeater 205 is equal to the length NG of the signal output from the interleaver 203.
The adder 207 performs an exclusive OR (XOR) operation on the signal output from the interleaver 203 and the signal output from the Walsh code repeater 205 and outputs the resultant signal to the combiner 209.
A PAPR reduction sequence is a sequence for reducing the PAPR of a pilot symbol in the OFDM communication system and has a length of NR. Here, it is assumed that the PAPR reduction sequence has been determined in advance corresponding to the cell ID and the sector ID. The PAPR reduction sequence, having a length of NR, is input to the combiner 209. The combiner 209 allocates sub-carriers to the signal output from the adder 207 and the PAPR sequence so that the signal from the adder and the PAPR sequence can be carried by the sub-carriers, thereby generating and outputting a pilot symbol. Here, the pilot symbol output from the combiner 209 has a length of NP (NP=NG+NR).
Hereinafter, an internal structure of a transmitter will be described with reference to FIG. 3 which is a block diagram illustrating an internal structure of a transmitter of an OFDM communication system according to an embodiment of the present invention.
Referring to FIG. 3, the transmitter includes a first modulator 301, a pilot signal generator 303, a second modulator 305, a selector 307, a serial-to-parallel converter 309, an Inverse Fast Fourier Transform (IFFT) unit 311, a parallel-to-serial converter 313, a guard interval inserter 315, a digital-to-analog converter 317, a Radio Frequency (RF) processor 319.
First, when there is data to be transmitted (i.e. information data bits), the information data bits are input to the first modulator 301. The first modulator 301 generates a modulated symbol by modulating the input information data bits according to a predetermined modulation scheme and outputs the modulated symbol to the selector 307. Here, various schemes such as a Quadrature Phase Shift Keying (QPSK) scheme or a 16-ary Quadrature Amplitude Modulation (16QAM) scheme are available for the modulation scheme.
When it is necessary to transmit a pilot signal (i.e. pilot symbol), a cell ID and a sector ID of a cell and sector to which the pilot symbol will be transmitted and a PAPR reduction sequence, set in advance correspondingly to the cell ID and the sector ID, are input to the pilot signal generator 303. The pilot signal generator 303 generates a pilot symbol by using the input cell ID, sector ID, and the PAPR reduction sequence and outputs the generated pilot symbol to the second modulator 305. Here, the pilot signal generator 303 has an internal structure as shown in FIG. 2. Upon receiving the signal output from the pilot signal generator 303, the second modulator 305 generates a modulated symbol by modulating the signal according to a predetermined modulation scheme and outputs the modulated symbol to the selector 307. Here, a Binary Phase Shift Keying (BPSK) scheme, etc., may be used as the modulation scheme.
In a data symbol transmission interval in which the transmitter must transmit a current data symbol, the selector 307 allows the signal from the first modulator 301 to be output to the serial-to-parallel converter 309. In contrast, in a pilot symbol transmission interval in which the transmitter must transmit a current pilot symbol, the selector 307 allows the signal from the second modulator 305 to be output to the serial-to-parallel converter 309. The serial-to-parallel converter 309 converts the serial modulation symbols output from the selector 307 into parallel symbols and outputs the parallel symbols to the IFFT unit 311. The IFFT unit 311 performs an N-point IFFT on the signal output from the serial-to-parallel converter 309 and then outputs the IFFT-processed signal to the parallel-to-serial converter 313.
The parallel-to-serial converter 313 converts the signals output from the IFFT unit 311 into a serial signal and outputs the serial signal to the guard interval inserter 315. The guard interval inserter 315 inserts a guard interval into the signal output from the parallel-to-serial converter 313 and then outputs a resultant signal to the digital-analog converter 317. Here, the guard intervals are inserted in order to eliminate interference, between an OFDM symbol transmitted during a previous OFDM symbol time and an OFDM symbol transmitted during a current OFDM symbol time, in transmission of the OFDM symbols in the OFDM communication system. In inserting the guard intervals, a cyclic prefix method or a cyclic postfix method may be used. In the cyclic prefix method, a predetermined number of last samples of an OFDM symbol in a time domain are copied and inserted into a valid OFDM symbol. In the cyclic postfix method, a predetermined number of first samples of an OFDM symbol in a time domain are copied and inserted into a valid OFDM symbol. The signal output from the guard interval inserter 315 serves as one OFDM symbol.
The digital-analog converter 317 converts the signal output from the guard interval inserter 315 into an analog signal and outputs the analog signal to the RF processor 319. Here, the RF processor 319 includes a filter and a front end unit, etc. The RF processor 319 processes the signal output from the digital-analog converter 317 and transmits the signal over the air through an antenna.
Hereinafter, an internal structure of a receiver of an OFDM communication system according to an embodiment of the present invention will be described with reference to FIG. 4.
Referring to FIG. 4, the receiver includes an RF processor 401, an analog-to-digital converter 403, a guard interval remover 405, a serial-to-parallel converter 407, a Fast Fourier Transform (FFT) unit 409, a parallel-to-serial converter 411, a selector 413, a first demodulator 415, a second demodulator 417, and a cell ID/sector ID detector 419.
First, a signal transmitted from the transmitter of the OFDM communication system, together with noise added to the signal while the signal passes through a multipath channel, is received via a receive antenna of the receiver. The signal received through the receive antenna is input to the RF processor 401. The RF processor 401 down-converts the signal received through the reception signal into a signal having an Intermediate Frequency (IF) band and outputs the down-converted signal to the analog-to-digital converter 403. The analog-to-digital converter 403 converts the analog signal from the RF processor 401 into a digital signal and outputs the digital signal to the guard interval remover 405.
Upon receiving the digital signal from the analog-to-digital converter 403, the guard interval remover 405 removes the guard interval from the digital signal and outputs the signal to the serial-to-parallel converter 407. The serial-to-parallel converter 407 converts the serial signal into parallel signals and sends the parallel signals to the FFT unit 409. The FFT unit 409 performs an N-point FFT on the parallel signals output from the serial-to-parallel converter 407 and outputs the FFT-processed signals to the parallel-to-serial converter 411.
The parallel-to-serial converter 411 converts the parallel signals from the FFT unit 409 into a serial signal and sends the serial signal to the selector 413. In a data symbol reception interval in which the receiver must receive a current data symbol, the selector 413 allows the signal from the parallel-to-serial converter 411 to be sent to the first demodulator 415. In contrast, in a pilot symbol reception interval in which the receiver must receive a current pilot symbol, the selector 413 allows the signal from the parallel-to-serial converter 411 to be sent to the second demodulator 417. The first demodulator 415 demodulates the signal output from the selector 413 according to a demodulation scheme, corresponding to the modulation scheme employed in the transmitter, and outputs data (i.e. information data bits) restored through the demodulation.
Meanwhile, the second demodulator 417 demodulates the signal output from the selector 413 according to a demodulation scheme, corresponding to the modulation scheme employed in the transmitter, and outputs a pilot signal restored through the demodulation to the cell ID/sector ID detector 419. The cell ID/sector ID detector 419 receives the pilot signal from the second demodulator 417 and detects a cell ID and a sector ID corresponding to the pilot signal. Here, the pilot signal is a signal, generated corresponding to the cell ID and the sector ID, that has been agreed in advance by a protocol between the transmitter and the receiver.
Hereinafter, an internal structure of an cell ID/sector ID detector will be described with reference to FIG. 5 which is a block diagram illustrating an internal structure of the cell ID/sector ID detector 419 of FIG. 4.
Referring to FIG. 5, the cell ID/sector ID detector 419 includes a pilot signal extractor 501, a Walsh code repeater 503, an adder 505, a deinterleaver 507, a sub-block divider 509, a block code decoder 511, a combiner 523 and a comparison selector 525. The block code decoder 511 includes a multiplier 513, a mask sequence generator 515, an IFHT unit 517, a memory 519 and a controller 521.
First, the signal output from the second demodulator 417 of FIG. 4 is input to the pilot signal extractor 501. The pilot signal extractor 501 extracts an NG number of symbols by eliminating the PAPR sequence from the signal output from the second demodulator 417 and outputs the extracted symbols to the adder 505. Further, the Walsh code repeater 503 repeatedly outputs Walsh codes corresponding to all sector IDs which can be identified by the receiver, sequentially selects one Walsh code from among the Walsh codes corresponding to the all sector IDs, and repeatedly outputs the selected Walsh code to the adder 505.
The adder 505 performs an XOR operation on the signal output from the pilot signal extractor 501 and the signal output from the Walsh code repeater 503 and sends the XOR-operated signal to the deinterleaver 507. The deinterleaver 507 deinterleaves the signal output from the adder 505 according to the same interleaving scheme as that employed by the interleavers in the pilot signal generator of the transmitter (i.e. the interleaver 203 of FIG. 2) and outputs the deinterleaved signal to the sub-block divider 509.
Upon receiving the deinterleaved signal from the deinterleaver 507, the sub-block divider 509 divides the signal into sub-blocks and outputs the sub-blocks from in the generator matrix G of the transmitter described above with reference to Equation (1). That is, the sub-block divider 509 divides the signal into a sub-blocks and sequentially outputs the sub-blocks to the block code decoder 511. Specifically, the sub-block divider 509 divides the signal output from the deinterleaver 507 into a sub-blocks, stores the a sub-blocks in an internal memory (not shown), and sequentially outputs the sub-blocks from the first sub-block while delaying the other sub-blocks until the final sub-block (i.e. the a-th sub-block) is output to the block code decoder 511.
The signal output from the sub-block divider 509 is input to the multiplier 513 of the block code decoder 511. The multiplier 513 multiplies the mask sequence output from the mask sequence generator 515 by the signal output from the sub-block divider 509 and then outputs the resultant signal to the IFHT unit 517. The mask sequence generator 515 sequentially generates the mask sequences used in the block code generator matrix G of the transmitter and outputs them to the multiplier 513 under the control of the controller 521.
Upon receiving the signal output from the multiplier 513, the IFHT unit 517 performs an IFHT operation on the signal and then outputs the IFHT-performed signal to the memory 519. The memory 519 stores the signal from the IFHT unit 517 and outputs the signal to the controller 521. The controller 521 controls the operation of the mask sequence generator 515 for generating the mask sequence. Further, after the mask sequence generator 515 generates all of the mask sequences used in the block code generator matrix G of the transmitter, the controller 521 controls the output signal of the IFHT unit 517 corresponding to the mask sequences of the corresponding sub-blocks of the output signal of the deinterleaver 507 stored in the memory 519 to be output to the combiner 523.
The combiner 523 stores the signal output from the controller 521 for the a sub-blocks, combines the output values output from the IFHT unit 517 in accordance with the block code generator matrix G of the transmitter, and then outputs the combined signal to the comparison selector 525.
The comparison selector 511 selects a maximum correlation value from among the output correlation values of the combiner 523 for the block codes corresponding to all the cell IDs and the Walsh codes corresponding to all the sector IDs, and outputs a cell ID and a sector ID corresponding to the selected maximum correlation value.
Hereinafter, the operation of the transmitter will be described with reference to FIG. 6 which is a flowchart of an operation process of a transmitter in an OFDM communication system according to an embodiment of the present invention.
In the following description with reference to FIG. 6, the transmission of the pilot signal by the transmitter will be mainly discussed and the transmission of the data signal will not be dealt with in detail since the latter has no direct relation to the present invention. First, in step 611, the transmitter generates a pilot symbol by using a cell ID of the transmitter, a sector ID, and a PAPR reduction sequence. The operation of generating the pilot symbol is the same as described above with reference to FIG. 2 and will thus be omitted here. In step 613, the transmitter generates a modulated symbol by modulating the pilot symbol according to a preset modulation scheme such as a BPSK scheme.
In step 615, the transmitter transmits the modulated pilot symbol in a pilot symbol interval and ends the process. Although not shown in FIG. 6, a frequency offset may be taken into consideration in transmitting the pilot symbol. That is, the location at which the pilot symbol begins may be set differently for each cell and each sector.
Hereinafter, the operation of the receiver will be described with reference to FIG. 7 which is a flowchart of an operation process of a receiver in an OFDM communication system according to an embodiment of the present invention.
In the following description with reference to FIG. 7, the reception of the pilot signal by the receiver will be mainly discussed and the reception of the data signal will not be dealt with in detail since the latter has no direct relation to the present invention. First, in step 711, the receiver receives the pilot symbol in a pilot symbol interval. Here, although not shown in FIG. 7, when the transmitter has transmitted the pilot symbol in consideration of the frequency offset as described above in relation to FIG. 6, the receiver determines the signal reception location corresponding to the frequency offset before receiving the pilot symbol. In step 713, the receiver demodulates the pilot symbol according to a demodulation scheme corresponding to the modulation scheme employed by the transmitter. In step 715, the receiver performs a correlation on the demodulated pilot symbol for block codes corresponding to all the cell IDs which can be identified by the receiver and the Walsh codes corresponding to said all cell IDs, detects a cell ID and a sector ID having a maximum correlation value as the cell ID and the sector ID of the transmitter, and then ends the process.
Hereinafter, the mapping relation between sub-carriers and pilot symbols when an IFFT is performed in an OFDM communication system according to an embodiment of the present invention will be described with reference to FIG. 8.
FIG. 8 is based on an assumption that the number of all sub-carriers in the OFDM communication system is 128 and the number of actually used sub-carriers from among the 128 sub-carriers is 108. In other words, 108 sub-carriers including 54 sub-carriers from a sub-carrier of No.−54 to a sub-carrier of No.−1 and 54 sub-carriers from a sub-carrier of No. 1 to a sub-carrier of No. 54 are actually used from among the 128 sub-carriers in the system. In FIG. 8, the number of each input port of the IFFT unit (that is, k) denotes an index of each sub-carrier. The sub-carrier of No. 0 represents a reference point for the pilot symbols in the time domain, that is, a DC component in the time domain after the IFFT is performed. Therefore, a null data is inserted into the sub-carrier of No. 0.
Further, the null data is also inserted into the other sub-carriers than the 108 actually used sub-carriers and the sub-carrier of No. 0. That is, the null data is inserted also into the sub-carriers from the sub-carrier of No.−55 to the sub-carrier of No.−64 and the sub-carriers from the sub-carrier of No. 55 to the sub-carrier of No. 63.
Here, the reason why the null data is inserted into the sub-carriers from the sub-carrier of No.−55 to the sub-carrier of No.−64 and the sub-carriers from the sub-carrier of No. 55 to the sub-carrier of No. 63 is that the sub-carriers from the sub-carrier of No.−55 to the sub-carrier of No.−64 and the sub-carriers from the sub-carrier of No. 55 to the sub-carrier of No. 63 are adjacent to the frequency bands of other systems. By inserting null data into such sub-carriers, it is possible to minimize interference with another system using a neighboring frequency band. Therefore, when the pilot symbol of the frequency domain has been input to the IFFT unit, the IFFT unit maps the input pilot symbol of the frequency domain to corresponding sub-carriers, performs an IFFT operation on the mapped symbol, and then outputs a resultant pilot symbol of the time domain.
FIG. 9 illustrates a frame structure of a pilot symbol in the time domain of an OFDM communication system according to an embodiment of the present invention.
Referring to FIG. 9, the pilot symbol includes twice repeated symbols each having the same length of pc (i.e. the same length of NFFT/2) and a guard interval signal added to the front end of the twice repeated symbols. The guard interval signal is inserted according to the Cyclic Prefix (CP) scheme as described above in consideration of the characteristics of the OFDM communication system. Here, NFFT denotes the number of points of the IFFT/FFT operation used in the OFDM communication system. That is, as described above with reference to FIG. 8, the number of points of the IFFT/FFT operation used in the OFDM communication system is 128, and the length of pc is 64.
FIG. 10 illustrates a structure of a pilot symbol in the frequency domain of an OFDM communication system according to an embodiment of the present invention.
Referring to FIG. 10, the sub-carrier interval except for the guard bands (i.e. guard intervals) 1001 and 1007 includes a correlation interval 1003 and a PAPR interval 1005. The correlation interval 1003 includes sequences having large correlation values (i.e. sequences generated by combining the block codes and the Walsh codes) and the PAPR interval 1005 includes PAPR reduction sequences corresponding to the sequences in the correlation interval 1003.
As shown in FIG. 10, the pilot symbol includes a first part sequence (i.e. a sequence corresponding to the correlation interval 1003) and a second part sequence (i.e. a sequence corresponding to the PAPR interval 1005). Hereinafter, the sequence inserted in the correlation interval 1003 (i.e. the sequence output from the adder 207 in FIG. 2) will be referred to as “correlation sequence”. The calculation of the correlation values as described above with reference to FIG. 5 is performed only for the correlation interval 1003.
In FIG. 10, C denotes a block code having a length of 48 and Π(•) denotes an interleaving scheme having a length of 48 by which the block code having a length of 48 is interleaved. Further, W(•) denotes a Walsh code masking.
The pilot symbol is generated by frequency domain sequences as expressed by Equation (2) below.




  
    
      
        
          
            P
            
              ID
              
                cell
                ,
                S
              
            
          
          ⁡
          
            [
            k
            ]
          
        
        =
        
          {
          
            
              
                
                  
                    
                      
                        
                          
                            2
                          
                          ⁢
                          
                            (
                            
                              1
                              -
                              
                                2
                                ⁢
                                
                                  
                                
                                ⁢
                                
                                  
                                    q
                                    
                                      ID
                                      
                                        cell
                                        ,
                                        S
                                      
                                    
                                  
                                  ⁡
                                  
                                    [
                                    m
                                    ]
                                  
                                
                              
                            
                            )
                          
                        
                        ,
                      
                    
                    
                      
                        
                          k
                          =
                          
                            
                              2
                              ⁢
                              
                                
                              
                              ⁢
                              m
                            
                            -
                            
                              
                                N
                                used
                              
                              2
                            
                          
                        
                        ,
                      
                    
                  
                  
                    
                      
                        
                      
                    
                    
                      
                        
                          m
                          =
                          0
                        
                        ,
                        1
                        ,
                        ...
                        ⁢
                        
                          
                        
                        ,
                        
                          
                            
                              N
                              used
                            
                            4
                          
                          -
                          1
                        
                      
                    
                  
                  
                    
                      
                        
                          
                            2
                          
                          ⁢
                          
                            (
                            
                              1
                              -
                              
                                2
                                ⁢
                                
                                  
                                
                                ⁢
                                
                                  
                                    q
                                    
                                      ID
                                      
                                        cell
                                        ,
                                        S
                                      
                                    
                                  
                                  ⁡
                                  
                                    [
                                    
                                      m
                                      -
                                      1
                                    
                                    ]
                                  
                                
                              
                            
                            )
                          
                        
                        ,
                      
                    
                    
                      
                        
                          k
                          =
                          
                            
                              2
                              ⁢
                              m
                            
                            -
                            
                              
                                N
                                used
                              
                              2
                            
                          
                        
                        ,
                      
                    
                  
                  
                    
                      
                        
                      
                    
                    
                      
                        
                          m
                          =
                          
                            
                              
                                N
                                used
                              
                              4
                            
                            +
                            1
                          
                        
                        ,
                        
                          
                            
                              N
                              used
                            
                            4
                          
                          +
                          2
                        
                        ,
                        ...
                        ⁢
                        
                          
                        
                        ,
                        
                          
                            N
                            used
                          
                          2
                        
                      
                    
                  
                  
                    
                      
                        0
                        ,
                      
                    
                    
                      otherwise
                    
                  
                
                ⁢
                
                  

                
                ⁢
                
                  ID
                  cell
                
              
              ∈
              
                {
                
                  0
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  126
                
                }
              
            
            ,
            
              s
              ∈
              
                {
                
                  0
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  7
                
                }
              
            
            ,
            
              

            
            ⁢
            
              k
              ∈
              
                
                  {
                  
                    
                      
                        -
                        
                          N
                          FFT
                        
                      
                      /
                      2
                    
                    ,
                    
                      
                        
                          -
                          
                            N
                            FFT
                          
                        
                        /
                        2
                      
                      +
                      1
                    
                    ,
                    ...
                    ⁢
                    
                      
                    
                    ,
                    
                      
                        
                          N
                          FFT
                        
                        ⁢
                        2
                      
                      -
                      1
                    
                  
                  }
                
                .
              
            
          
        
      
    
    
      
        (
        2
        )
      
    
  




In Equation (2), IDcell denotes a cell ID (i.e. ID of a BS), s denotes a sector ID, k denotes a sub-carrier index, and Nused denotes the number of sub-carriers actually used in the OFDM communication system (i.e. the number of sub-carriers except for the DC component and the guard interval component). In the present embodiment, it is assumed that the pilot symbols of all BSs and sectors use the same frequency offset. According to the frequency domain sequence PIDcells,S[k] as shown in Equation (2), the values in the form as shown in Equation (2) are assigned only to sub-carriers having an even number of indices and a value of 0 is unconditionally assigned to all sub-carriers having an odd number of indices. Therefore, when the IFFT operation has been performed, the same sequence is repeated twice in the time domain.
Further, in Equation (2), √{square root over (2)} is a weight value in order to enable the pilot symbol to have the same transmit power level as the transmit power level of the data symbol transmitted in an interval (i.e. data symbol interval) other than the pilot symbol interval. qIDcell,S[m] is defined by Equation (3) below.




  
    
      
        
          
            q
            
              
                ID
                cell
              
              ,
              S
            
          
          ⁡
          
            [
            m
            ]
          
        
        =
        
          {
          
            
              
                
                  
                    R
                    ⁡
                    
                      (
                      
                        
                          8
                          *
                          
                            ⌊
                            
                              m
                              9
                            
                            ⌋
                          
                        
                        +
                        
                          m
                          ⁢
                          
                            
                          
                          ⁢
                          mod
                          ⁢
                          
                            
                          
                          ⁢
                          9
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    
                      where
                      ⁢
                      
                        
                      
                      ⁢
                      m
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      9
                    
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  7
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  53
                
              
            
            
              
                
                  
                    T
                    ⁡
                    
                      (
                      
                        ⌊
                        
                          m
                          9
                        
                        ⌋
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    where
                    ⁢
                    
                      
                    
                    ⁢
                    m
                    ⁢
                    
                      
                    
                    ⁢
                    mod
                    ⁢
                    
                      
                    
                    ⁢
                    9
                  
                  =
                  8
                
              
            
          
        
      
    
    
      
        (
        3
        )
      
    
  




In Equation (3),




  ⌊
  
    m
    9
  
  ⌋




represents a maximum integer not larger than





  
    m
    9
  
  .




In Equation (3), R(r) can be expressed by Equation (4) below.





  
    
      
        
          
            
              
                
                  R
                  ⁡
                  
                    (
                    r
                    )
                  
                
                =
                
                  
                    w
                    
                      r
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      8
                    
                    s
                  
                  ⊕
                  
                    
                      b
                      
                        IDcell
                        +
                        1
                      
                    
                    ⁢
                    
                      g
                      
                        ∏
                        
                          (
                          r
                          )
                        
                      
                    
                  
                
              
              ,
            
          
        
        
          
            
              
                r
                =
                
                  
                    
                      8
                      *
                      
                        ⌊
                        
                          m
                          9
                        
                        ⌋
                      
                    
                    +
                    
                      m
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      9
                    
                  
                  =
                  0
                
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              47
            
          
        
      
    
    
      
        (
        4
        )
      
    
  




In Equation (4), Wsr mod8 represents the repetition of the Walsh codes having a length of 8 and a sector ID corresponding to s. Further, a certain decimal number k (1≦k≦127) is expressed as a binary number of b6b5b4b3b2b1b0, wherein bk represents a row vector (bk={b6b5b4b3b2b1b0}) when b6 is the Most Significant Bit (MSB) and b0 is the Least Significant Bit (LSB). Further, in equation (4), gu (0≦u≦47) represents the u-th column vector of the block code generator matrix G. The block code generator matrix G can be expressed by Equation (5) below.




As noted from Equation (5), the block code generator matrix G includes three sub-blocks each having a length of 16, in each of which the Walsh bases are marked by the dotted lines. The Walsh bases and mask sequences in Equation (5) can be expressed as Table 1.










TABLE 1









Walsh basis
0101010101010101




0011001100110011




0000111100001111




0000000011111111



Mask(1)
0000001101010110



Mask(2)
0000010101100011



Mask(3)
0001000100010001










Meanwhile, in Equation (5), bkgu represents a matrix product between a (1×7) row vector and (7×1) column vector and has a scalar value which is calculated through operations including modulo 2 addition and multiplication. In Equation (5), Π(r) (0≦r≦47) represents the interleaving scheme of the interleaver 203 as described above with reference to FIG. 2. The interleaving scheme can be expressed as Table 2 below.








TABLE 2







Π(r)
9, 7, 14, 15, 10, 1, 2, 5, 3, 8, 0, 4, 13, 11, 6, 12, 27, 29, 21, 18,



16, 25, 23, 17, 24, 19, 28, 31, 26, 20, 30, 22, 38, 47, 41, 42, 37,



46, 39, 45, 32, 34, 40, 33, 35, 43, 36, 44









That is to say, the interleaving scheme Π(r) uses permutation of the locations of 48 elements in the block code having a length of 48 according to the order shown in Table 2. In Table 2, each number indicates the index of a sub-carrier to which an element of the block code is one-to-one mapped.
It is noted from the interleaving scheme shown in Table 2 that an interleaving scheme having a length of 16 is concatenated three times as shown in Table 3 below.








TABLE 3







1st interleaving scheme
9, 7, 14, 15, 10, 12, 5, 3, 8, 0, 4, 13, 11, 6, 12


2nd interleaving scheme
11, 13, 5, 20, 9, 7, 18, 3, 1, 2, 1, 5, 10, 4, 14, 6


3rd interleaving scheme
6, 15, 9, 10, 5, 14, 7, 13, 0, 2, 8, 1, 3, 11, 4, 12









In Table 3, each number indicates the index of a sub-carrier to which each element of the three sub-codes is one-to-one mapped.
Further, in Equation (3), the value of the sequence




  
    T
    ⁡
    
      (
      s
      )
    
  
  ⁢
  
    
  
  ⁢
  
    (
    
      
        s
        =
        
          
            ⌊
            
              m
              9
            
            ⌋
          
          =
          0
        
      
      ,
      1
      ,
      ...
      ⁢
      
        
      
      ,
      5
    
    )
  




is determined by the PAPR reduction sequence which minimizes the PAPR of the pilot symbol. Table 4 shows PAPR reduction sequences corresponding to the cell IDs and sector IDs and PAPRs of pilot symbols corresponding to the cell IDs and sector IDs.

Table 4













TABLE 4







IDcell
S
PAPR reduction sequence
PAPR(dB)









0
0
001100
6.18158



0
1
100110
6.30181



0
2
101011
4.35385



0
3
000101
5.33634



0
4
110111
5.06097



0
5
110111
6.58247



0
6
000100
5.3471 



0
7
101110
7.09793



1
0
010000
5.75956



1
1
100011
5.67524



1
2
000000
5.28916



1
3
111010
5.68051



1
4
010011
6.70095



1
5
010011
5.61945



1
6
001100
5.46733



1
7
101111
5.92966










The method of transmitting/receiving pilot signals as described above may be also employed in an OFDM communication system using multiple antennas and requiring no sector differentiation. For example, when a transmitter of such an OFDM communication system uses an Nt number of transmit antennas, the pilot symbols transmitted through each of the Nt transmit antennas can be expressed by Equation (6) below.




  
    
      
        
          
            
              
                
                  P
                  
                    ID
                    
                      cell
                      ,
                      n
                    
                  
                
                ⁡
                
                  [
                  k
                  ]
                
              
              =
              
                {
                
                  
                    
                      
                        
                          1
                          -
                          
                            2
                            ⁢
                            
                              
                                q
                                
                                  ID
                                  cell
                                
                              
                              ⁡
                              
                                [
                                m
                                ]
                              
                            
                          
                        
                        ,
                      
                    
                    
                      
                        
                          k
                          =
                          
                            
                              
                                N
                                t
                              
                              ⁢
                              m
                            
                            -
                            
                              
                                N
                                used
                              
                              2
                            
                            +
                            n
                          
                        
                        ,
                      
                    
                  
                  
                    
                      
                        
                      
                    
                    
                      
                        
                          m
                          =
                          0
                        
                        ,
                        1
                        ,
                        ...
                        ⁢
                        
                          
                        
                        ,
                        
                          
                            
                              N
                              used
                            
                            
                              N
                              t
                            
                          
                          -
                          1
                        
                      
                    
                  
                  
                    
                      
                        0
                        ,
                      
                    
                    
                      otherwise
                    
                  
                
              
            
          
        
        
          
            
              
                
                  ID
                  cell
                
                ∈
                
                  {
                  
                    0
                    ,
                    1
                    ,
                    ...
                    ⁢
                    
                      
                    
                    ,
                    126
                  
                  }
                
              
              ,
              
                n
                =
                0
              
              ,
              1
              ,
              
                
                  ...
                  ⁢
                  
                    
                  
                  ⁢
                  
                    N
                    t
                  
                
                -
                1
              
              ,
            
          
        
        
          
            
              k
              ∈
              
                {
                
                  
                    -
                    
                      
                        N
                        FFT
                      
                      2
                    
                  
                  ,
                  
                    
                      -
                      
                        
                          N
                          FFT
                        
                        2
                      
                    
                    +
                    1
                  
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      
                        N
                        FFT
                      
                      2
                    
                    -
                    1
                  
                
                }
              
            
          
        
      
    
    
      
        (
        6
        )
      
    
  




In Equation (6), n denotes the number of the transmit antennas and k denotes a sub-carrier index. Further, qIDcell[m] in Equation (6) can be defined as Equation (7) below.




  
    
      
        
          
            q
            
              ID
              cell
            
          
          ⁡
          
            [
            m
            ]
          
        
        =
        
          {
          
            
              
                
                  
                    R
                    ⁡
                    
                      (
                      
                        
                          8
                          *
                          
                            ⌊
                            
                              m
                              9
                            
                            ⌋
                          
                        
                        +
                        
                          m
                          ⁢
                          
                            
                          
                          ⁢
                          mod
                          ⁢
                          
                            
                          
                          ⁢
                          9
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    
                      where
                      ⁢
                      
                        
                      
                      ⁢
                      m
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      9
                    
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  7
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      
                        N
                        t
                      
                    
                    -
                    1
                  
                
              
            
            
              
                
                  
                    T
                    ⁡
                    
                      (
                      
                        ⌊
                        
                          m
                          9
                        
                        ⌋
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    where
                    ⁢
                    
                      
                    
                    ⁢
                    m
                    ⁢
                    
                      
                    
                    ⁢
                    mod
                    ⁢
                    
                      
                    
                    ⁢
                    9
                  
                  =
                  8
                
              
            
          
        
      
    
    
      
        (
        7
        )
      
    
  




In Equation (7), each of the two sequences R(r) and T(k) is differently defined according to the number Nt of the transmit antennas and the number of points of the FFT operation used in the OFDM communication system, so that the sequence qIDcell[m] also is differently defined according to the number Nt of the transmit antennas and the number of points of the FFT operation used in the OFDM communication system.
Hereinafter, the above-mentioned R(r), T(k), and qIDcell[m] according to the number Nt of the transmit antennas and the number of points of the FFT operation used in the OFDM communication system will be described.
First, when the number Nt of the transmit antennas is two and the number of the FFT operation points used in the OFDM communication system is 128 (i.e. Nt=2, NFFT=128), R(r) can be expressed by Equation (8) below.




  
    
      
        
          
            R
            ⁡
            
              (
              r
              )
            
          
          =
          
            
              B
              
                IDcell
                
                  +
                  1
                
              
            
            ⁢
            
              g
              
                ∏
                
                  (
                  r
                  )
                
              
            
          
        
        ,
        
          r
          =
          
            
              
                8
                *
                
                  ⌊
                  
                    m
                    9
                  
                  ⌋
                
              
              +
              
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
            
            =
            0
          
        
        ,
        1
        ,
        ...
        ⁢
        
          
        
        ,
        47
      
    
    
      
        (
        8
        )
      
    
  




In Equation (8), the block code generator matrix G is the same as that in Equation (4) and the interleaving scheme can be expressed by Table 5 below.








TABLE 5







Π(l)
5, 6, 4, 10, 7, 2, 14, 0, 8, 11, 13, 12, 3, 15, 1, 9, 26, 29, 19,



27, 31, 17, 20, 16, 23, 28, 24, 21, 18, 30, 25, 22, 43, 46, 34, 47,



44, 41, 37, 36, 39, 38, 35, 33, 32, 45, 40, 42









Meanwhile, T(k) in Equation (7) has values as expressed by the hexadecimal numbers shown in Table 6 below and qIDcell[m] can be expressed by the hexadecimal numbers as shown in Table 7.









TABLE 6





ID cell
sequence
papr

















0
1 1 1 0 1 1
6.67057


1
0 0 1 1 0 0
5.883


2
1 1 1 1 1 1
4.95588


3
0 1 1 0 0 1
4.92942


4
1 0 0 1 0 0
4.84232


5
0 1 0 1 0 0
5.97707


6
0 0 0 0 1 1
5.2818


7
0 1 1 1 0 1
4.62935


8
1 1 1 1 0 1
4.80191


9
0 1 1 1 1 0
4.62839


10
1 0 0 0 0 0
4.93818


11
0 0 0 0 1 0
4.62239


12
1 1 0 0 1 1
6.23206


13
0 0 0 0 0 1
4.76556


14
1 1 0 1 1 1
5.21957


15
0 1 1 0 0 0
5.73261


16
0 0 1 1 1 0
4.9981


17
0 1 1 0 0 0
5.23977


18
1 1 1 1 1 0
5.59862


19
0 1 1 1 0 1
6.75846


20
0 0 1 1 1 1
4.86729


21
1 1 0 0 0 0
5.57405


22
1 0 1 0 0 1
4.82303


23
0 1 0 1 0 1
4.54948


24
0 1 1 1 0 1
5.45765


25
1 1 0 0 0 1
4.91648


26
1 0 0 1 0 1
3.95813


27
1 0 0 0 0 1
6.03433


28
1 1 0 0 0 1
4.50629


29
0 1 0 0 0 1
4.80454


30
1 0 1 1 1 1
4.94614


31
1 0 1 1 0 0
4.54236


32
0 1 1 0 0 0
3.86311


33
0 1 1 0 0 0
5.18297


34
1 1 0 1 0 1
5.59137


35
1 0 0 1 0 0
5.51632


36
1 1 0 0 1 0
4.64969


37
1 1 1 0 0 0
5.59862


38
0 0 0 0 1 1
6.56393


39
1 0 1 0 0 0
6.63257


40
0 0 1 0 1 1
6.30937


41
0 0 0 1 0 1
5.76388


42
0 0 0 1 1 1
5.17733


43
1 0 0 1 1 0
6.50695


44
0 0 0 0 0 1
5.58222


45
1 1 1 0 1 1
5.19814


46
1 0 0 1 1 0
5.50865


47
1 0 0 0 0 0
5.40503


48
1 0 0 1 0 0
4.48416


49
0 1 0 0 1 1
5.59962


50
0 1 0 1 0 0
4.76603


51
0 1 1 1 0 1
4.87033


52
1 1 1 0 0 1
5.60052


53
1 0 1 0 0 1
4.18939


54
1 1 1 1 0 1
5.00411


55
1 1 1 1 0 0
4.31284


56
0 0 0 0 1 0
5.32296


57
0 0 0 0 1 0
5.39012


58
0 1 1 0 0 1
6.0232


59
1 1 0 1 0 0
5.27241


60
0 0 1 0 1 0
5.26582


61
1 0 0 0 0 1
5.47146


62
0 0 0 0 1 0
5.43249


63
1 0 0 1 1 1
4.69906


64
1 1 1 0 0 0
5.29969


65
1 0 1 0 1 1
6.66865


66
1 0 1 0 1 1
5.90593


67
0 1 1 1 0 0
5.13642


68
0 0 1 0 0 0
4.9337


69
0 1 1 0 1 0
5.13715


70
1 1 1 1 0 0
5.05877


71
1 0 0 1 0 0
5.42538


72
1 1 1 0 1 0
5.21428


73
1 0 1 1 0 1
4.27288


74
0 1 0 0 0 1
4.63478


75
1 0 1 0 0 1
5.47216


76
1 0 1 0 0 0
6.48514


77
1 1 0 0 0 0
5.95897


78
0 0 0 0 0 1
5.59862


79
0 1 0 0 0 0
5.38694


80
0 0 0 0 1 0
4.79522


81
0 0 1 1 1 0
5.03585


82
1 1 0 0 1 1
6.41538


83
0 1 1 0 0 1
5.92329


84
1 0 1 1 1 0
5.24541


85
0 0 0 0 0 1
6.41868


86
1 0 1 0 1 1
5.47231


87
0 1 0 1 1 1
4.27052


88
0 0 0 1 0 1
4.98455


89
0 0 0 1 0 1
4.85573


90
1 0 1 1 0 0
4.66224


91
0 1 1 0 0 1
5.59862


92
0 1 0 1 0 1
5.13782


93
1 1 0 0 0 0
5.73533


94
0 1 1 1 1 1
6.31115


95
0 1 1 1 0 1
4.76096


96
0 1 0 1 1 1
4.43229


97
1 0 0 1 1 1
4.52351


98
1 0 0 1 0 0
4.16266


99
1 1 1 0 1 0
5.72573


100
0 1 0 1 0 0
4.34746


101
1 0 0 1 0 0
6.81937


102
0 1 0 1 1 1
5.86829


103
0 1 0 1 1 0
5.22038


104
1 0 0 0 0 0
4.8724


105
0 1 1 0 1 1
6.7858


106
1 0 0 0 1 0
5.75267


107
1 1 0 0 1 1
5.1796


108
1 1 1 0 0 0
6.00083


109
1 0 1 0 0 1
4.6724


110
1 0 0 1 0 0
4.8345


111
0 0 1 1 1 0
4.05646


112
0 0 1 1 1 1
5.6271


113
0 1 1 1 1 1
5.59862


114
1 1 0 0 1 0
4.90494


115
0 0 1 1 0 0
5.95286


116
0 1 1 0 0 1
5.99303


117
0 1 0 0 1 1
3.97648


118
0 1 0 1 0 0
5.71222


119
0 0 0 0 1 1
4.81998


120
1 1 1 1 1 0
4.67909


121
1 0 0 1 1 0
5.53328


122
0 0 0 1 1 0
5.20303


123
0 1 1 0 0 0
5.00673


124
1 0 1 1 1 0
4.57847


125
0 1 1 1 0 0
4.79082


126
1 1 0 1 0 0
4.91901


















TABLE 7





ID cell
sequence
papr

















0
88B7E232CDC83C
6.67057


1
5E260E301C4620
5.883


2
D691EC22D18E1C
4.95588


3
EA1A5F3245640C
4.92942


4
62ADBD0098A430
4.84232


5
B43C5102592228
5.97707


6
3C0BB31084EA14
5.2818


7
127AEE31B90504
4.62935


8
9ACD4C2374C53C
4.80191


9
4C5CE021B54B20
4.62839


10
C4EB0213688318
4.93818


11
F860B103EC6908
4.62239


12
70D7531121A934
6.23206


13
A646BF13E0272C
4.76556


14
2EF15D013DEF14
5.21957


15
4A30D2BAA965A0
6.73261


16
C20730A874AD98
4.9981


17
1416DCAAA52380
5.23977


18
9CA17EB878EBB8
5.59862


19
A02ACDA8FC01AC
6.75846


20
281D2FBA31C994
4.86729


21
FE8CC398E04788
5.57405


22
76BB21AA2D87B4
4.82303


23
584A7C8B1060A4
4.54948


24
D07DDEB9DDA09C
5.45765


25
06EC729B0C2684
4.91648


26
8EDB9089D1E6BC
3.95813


27
B2D023994504AC
6.03433


28
3AE7C18B88C494
4.50629


29
EC766D8949428C
4.80454


30
64C18FBB948AB4
4.94614


31
9A82B62CDF0708
4.54236


32
1235543E02C730
3.86311


33
C424F83CC34128
5.18297


34
4C935A0E1E8114
5.59137


35
7098A91E9A6300
5.51632


36
F8AF4B0C47AB38
4.64969


37
2EBEE72E862520
5.59862


38
A609051C4BED1C
6.56393


39
88F8183D660208
6.63257


40
004FBA2FABCA34
6.30837


41
D65E160D7A442C
5.76388


42
5E69B41FB78C14
5.17733


43
62E2070F336E00
6.50695


44
EA55A51DEEA63C
5.58222


45
3CC4493F2F2824
5.19814


46
B4F3AB0DF2E818
5.50865


47
D0B224966662A8
5.40503


48
58858684BBA290
4.48416


49
8E146A866A2C8C
5.59862


50
0623C894B7E4B0
4.76609


51
3A287BA43306A4
4.87033


52
B29FD9B6EEC69C
5.60052


53
648E35B42F4084
4.18939


54
ECB9D7A6F280BC
5.00411


55
C2C8CAA7DF67A8
4.91284


56
4A7F289502AF90
6.92296


57
9C6E8497C32988
5.39012


58
145966A50EE1B4
6.0232


59
28D2D5959A03A0
6.27241


60
A06537A747CB98
5.26582


61
76F49B85864584
5.47146


62
FE4339974B8DB8
6.43249


63
08A61410F5BE24
4.69906


64
8091F622287618
5.28969


65
56801A20E9F804
6.66865


66
DEB7B83224383C
5.90593


67
E23C4B22B0D228
6.13642


68
6A0BA9306D1210
4.9337


69
BC1A4532AC9C08
5.13715


70
34ADE720715430
5.05877


71
1ADCBA015CB320
5.42538


72
92EB5833817B18
5.21428


73
44FAB43150F504
4.27288


74
CC4D56038D353C
4.63478


75
F0C6A53309D72C
5.47216


76
78F10721C41710
6.49514


77
AEE0EB03059108
5.35897


78
26570911C85134
5.59862


79
4216C68A4CD380
5.36634


80
CA212498811BB8
4.79522


81
1C3088BA509DA0
5.03585


82
94876A888D5D9C
6.41538


83
A80CD9B809B78C
5.92329


84
20BB3BAAD47FB0
5.24541


85
F62A978805F1AC
6.41868


86
7E9D35BAC83994
5.47231


87
506C689BF5DE84
4.27052


88
D85B8A893816BC
4.98455


89
0E4A268BF990A4
4.85573


90
86FD84B9345098
4.66224


91
BA7677A9A0B28C
5.59862


92
3241D59B7D72B4
5.13782


93
E4D07999ACF4A8
5.73533


94
6C67DBAB713C94
6.31115


95
9224E23C3AB12C
4.76096


96
1A13400EF77914
4.43229


97
CC82AC0C36FF0C
4.52351


98
44B50E1EFB3730
4.16266


99
78BEFD2E6FDD20
5.72573


100
F0095F1CB21518
4.34746


101
2698B31E739300
6.81937


102
AE2F510CBE5B3C
5.86829


103
805E4C0D93BC28
5.22038


104
08E9AE1F4E7410
4.8724


105
DE78423D8FFA0C
6.7858


106
56CFA00F423A30
5.75267


107
6AC4531FC6D824
5.1796


108
E2F3F12D0B1018
6.00083


109
34E21D2FCA9604
4.6724


110
BCD5BF1D175638
4.8345


111
D81430A693DC88
4.05646


112
502392B45E1CB4
5.6271


113
86327EB69F9AAC
5.59862


114
0E85DC84425A90
4.90494


115
320E2FB4D6B080
5.95286


116
BA39CDA60B70BC
5.99303


117
6C286184CAFEA4
3.97648


118
E41FC396173698
5.71222


119
CA6E9E972AD98C
4.61398


120
42D97CA5F719B0
4.67909


121
94C89087369FA8
5.53328


122
1C7F3295FB5F90
5.20303


123
2074C1A56FB580
5.00679


124
A8C323B7B27DB8
4.57847


125
7E52CFB573F3A0
4.79082


126
F6E56D87BE3398
4.91901









Next, when the number Nt of the transmit antennas is three and the number of the FFT operation points used in the OFDM communication system is 128 (i.e. Nt=3, NFFT=128), R(r) can be expressed by Equation (9) below.




  
    
      
        
          
            R
            ⁡
            
              (
              r
              )
            
          
          =
          
            
              B
              
                IDcell
                
                  +
                  1
                
              
            
            ⁢
            
              g
              
                ∏
                
                  (
                  r
                  )
                
              
            
          
        
        ,
        
          r
          =
          
            
              
                8
                *
                
                  ⌊
                  
                    m
                    9
                  
                  ⌋
                
              
              +
              
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
            
            =
            0
          
        
        ,
        1
        ,
        ...
        ⁢
        
          
        
        ,
        31
      
    
    
      
        (
        9
        )
      
    
  




In Equation (9), the block code generator matrix G is expressed as shown by Equation (10) below and the interleaving scheme can be expressed by Table 8 below.




  
    
      
        
          
            
              G
              =
              
                [
                
                  
                    g
                    0
                  
                  ⁢
                  
                    
                  
                  ⁢
                  
                    g
                    1
                  
                  ⁢
                  
                    
                  
                  ⁢
                  ...
                  ⁢
                  
                    
                  
                  ⁢
                  
                    g
                    31
                  
                
                ]
              
            
          
        
        
          
            
              =
              
                [
                
                  
                    
                      01010101010101010000010101100011
                    
                  
                  
                    
                      00110011001100110001000100010001
                    
                  
                  
                    
                      00001111000011110101010101010101
                    
                  
                  
                    
                      00000000111111110011001100110011
                    
                  
                  
                    
                      00000011010101100000111100001111
                    
                  
                  
                    
                      00000101011000110000000011111111
                    
                  
                  
                    
                      00010001000100010000001101010110
                    
                  
                
                ]
              
            
          
        
      
    
    
      
        (
        10
        )
      
    
  












TABLE 8







Π(l)
11, 4, 12, 15, 0, 13, 5, 6, 14, 8, 10, 9, 1, 3, 2, 7, 16, 20, 31, 26,



22, 30, 27, 23, 19, 18, 17, 25, 21, 29, 24, 28









Meanwhile, T(k) in Equation (7) has values as expressed by the hexadecimal numbers shown in Table 9 below and qIDcell[m] can be expressed by the hexadecimal numbers as shown in Table 10.









TABLE 9





ID cell
sequence
papr

















0
0 0 1 1
4.49505


1
0 1 1 0
4.11454


2
0 1 1 0
6.0206


3
1 1 0 0
5.06896


4
0 0 0 0
4.51602


5
1 0 1 0
4.96176


6
0 0 0 1
4.50134


7
0 1 0 0
5.29586


8
1 1 1 1
5.37387


9
1 0 0 0
4.6668


10
0 1 1 0
5.09482


11
0 0 0 1
6.11344


12
0 0 0 0
5.71868


13
0 0 0 0
4.12233


14
0 1 1 1
4.44864


15
1 0 1 0
4.42172


16
1 0 0 0
4.43697


17
0 1 1 0
5.96559


18
0 0 1 0
5.31882


19
1 1 1 0
5.1578


20
0 0 1 1
4.18834


21
1 1 0 0
5.74259


22
1 0 1 0
6.10238


23
1 1 1 0
4.50069


24
1 0 0 1
4.38448


25
1 1 0 1
4.33171


26
1 0 0 1
5.31759


27
1 1 1 0
6.33599


28
1 1 0 1
4.55537


29
0 1 0 0
4.89809


30
1 0 1 1
4.45342


31
1 0 1 0
5.12448


32
1 0 0 0
4.43697


33
0 0 0 1
4.90907


34
1 0 0 1
3.9985


35
1 0 1 0
6.0206


36
0 0 0 1
5.39301


37
1 0 0 0
3.66487


38
1 0 1 1
4.92205


39
0 1 1 1
5.53843


40
0 1 1 1
5.26898


41
1 1 0 1
5.16959


42
0 1 1 0
5.34282


43
0 0 0 0
5.15133


44
1 0 0 1
4.87551


45
1 1 1 1
4.79443


46
1 0 1 0
5.07783


47
0 0 1 0
4.99682


48
1 0 1 1
5.94242


49
1 0 0 1
4.77698


50
1 0 0 0
5.03657


51
0 0 1 1
4.46604


52
1 0 0 0
5.68568


53
1 1 0 1
5.01898


54
0 1 1 1
4.95591


55
1 0 0 1
5.27862


56
1 1 1 0
6.0317


57
1 0 1 1
4.64979


58
1 1 0 0
5.02865


59
0 0 0 0
6.04332


60
0 0 0 1
4.44083


61
0 1 1 1
5.23739


62
1 0 1 0
6.43278


63
0 1 1 1
4.43697


64
1 0 1 1
4.43697


65
1 1 1 0
4.50516


66
1 0 0 1
4.58929


67
0 1 1 0
4.35849


68
0 0 0 0
5.13149


69
0 0 1 0
4.59563


70
0 1 0 1
4.73083


71
1 0 0 0
4.43697


72
1 0 0 0
4.44072


73
1 0 1 0
5.47799


74
1 1 1 0
4.92135


75
1 0 0 0
5.5708


76
1 0 0 0
4.48634


77
0 0 0 1
5.3005


78
1 0 1 1
5.8947


79
1 1 0 0
5.38806


80
0 0 1 0
4.74777


81
0 1 0 0
4.82428


82
1 0 0 0
4.45469


83
1 0 1 1
5.66832


84
1 1 0 0
4.50856


85
1 0 0 1
4.97948


86
1 0 1 1
4.68484


87
0 1 0 1
5.50907


88
1 0 1 0
5.38228


89
0 0 1 0
5.22999


90
1 1 1 0
5.0672


91
0 1 0 0
5.59042


92
0 1 0 1
4.95926


93
0 0 1 1
5.80828


94
1 0 1 1
5.40268


95
0 0 1 0
5.97897


96
1 0 0 1
3.99109


97
1 0 0 1
5.06574


98
0 0 0 1
6.08269


99
1 0 0 0
4.99827


100
0 0 1 1
4.70382


101
0 1 0 1
4.60731


102
0 1 0 0
5.05357


103
1 0 1 0
3.30653


104
1 0 1 1
4.52548


105
1 1 0 0
5.53041


106
0 1 1 0
6.04148


107
1 0 1 0
4.88727


108
0 0 1 0
5.40024


109
1 1 0 0
4.566


110
0 1 1 1
4.92798


111
1 0 1 1
5.17459


112
0 1 0 1
4.65719


113
1 1 1 0
4.94826


114
1 1 1 0
5.62084


115
0 0 1 0
4.77778


116
0 1 0 0
4.43697


117
0 1 1 0
4.24182


118
0 0 0 0
5.37234


119
1 1 1 0
4.46408


120
0 1 1 0
5.23129


121
1 1 0 0
5.9557


122
0 0 1 0
5.1374


123
1 0 0 0
5.35576


124
0 1 0 0
4.82596


125
1 1 1 0
4.45697


126
1 1 1 0
4.74343


















TABLE 10





ID cell
sequence
papr

















0
960E8D631
4.48505


1
9153C8F00
4.11454


2
075D45B30
6.0206


3
77COC8D78
5.06896


4
E14E05948
4.51602


5
E69300278
4.96176


6
701D8D449
4.50134


7
B4784FD80
5.29586


8
22F6C2BB1
5.37387


9
25AB87080
4.6668


10
B3254A6B0
6.09492


11
C338870F9
6.11344


12
55360A4C8
5.71868


13
526B0FDF8
4.12233


14
C465C2BC9
4.44864


15
85C88B61A
4.42172


16
13C61602A
4.45697


17
141B53B1A
5.96559


18
82159EF2A
5.31882


19
F28853B62
5.1578


20
64069EF53
4.18834


21
63D8DB462
5.74259


22
F5D516252
6.10238


23
31B0D4B9A
4.50063


24
A7BE19DAB
4.38448


25
A0E35C49B
4.33171


26
36ED910AB
6.31759


27
46F05C6E2
6.33599


28
D0FED10D3
4.55537


29
D723D48E2
4.83803


30
41AD19FD3
4.45342


31
12D88DA2E
5.12448


32
84D600C1E
4.43697


33
830B0552F
4.90907


34
15858811F
3.9985


35
659805756
6.0206


36
F31688167
5.39301


37
F4CB8D856
3.66497


38
62C500E67
4.92205


39
A620C27AF
5.53843


40
302E4F39F
5.26838


41
37F34A8AF
5.16959


42
A17DC7E9E
5.34282


43
D1600A8D6
5.15133


44
47EE87CE7
4.87551


45
40B3C27D7
4.79443


46
D6BD0F3E6
5.07783


47
971016E34
4.99682


48
019E9BA05
5.94242


49
06C39E135
4.77698


50
90CD13504
5.03657


51
E0509E34D
4.46604


52
76DE1357C
5.68568


53
718356C4D
5.01898


54
E70DDBA7D
4.95591


55
23E8191B5
5.27862


56
B5E6D4784
6.0317


57
B2BB91EB5
4.64379


58
24B55C884
5.02869


59
542891CCC
6.04332


60
C2261C8FD
4.44083


61
C57B593CD
5.23739


62
53F5947FC
6.45278


63
9002C3E29
4.43697


64
068CDEA19
4.43697


65
01D14B528
4.50516


66
97DFB6519
4.58929


67
E7424B350
4.35848


68
714C86560
5.13148


69
761183E50
4.59563


70
E01F4E861
4.73083


71
24FA8C1A8
4.43697


72
B2F4O1598
4.44072


73
B5A9O4EA8
5.47799


74
23A7C9A98
4.92135


75
53BA04CD0
5.5708


76
C5B4B98E0
4.49634


77
C2698C1D1
5.3005


78
54E7017E1
5.8947


79
15CA58832
5.38806


80
834495E02
4.74777


81
8419D0532
4.82428


82
12971D102
4.45469


83
628A9074B
5.66832


84
F4845D17A
4.50856


85
F3D91884B
4.97946


86
65D795E7B
4.68484


87
A132575B3
5.50907


88
37BC9A382
5.38228


89
30619FAB2
5.22999


90
A6EF52E82
5.0672


91
D672DF8CA
5.59042


92
407C52CFB
4.95926


93
4721177CB
3.80828


94
D1AF9A3FB
5.40268


95
825A0E606
5.97897


96
14D483037
3.99109


97
138986907
5.06574


98
85070BD37
6.08269


99
F59A8697E
4.39827


100
63140BF4F
4.70382


101
64494E47F
4.60731


102
F247C304E
5.05357


103
36A201B86
3.30653


104
A0AC8CFB7
4.52546


105
A7F1C9486
5.53041


106
317F442B6
6.04148


107
41E2896FE
4.88727


108
D76C042CE
5.40024


109
D0B1419FE
4.566


110
463FCCFCF
4.92796


111
07929521D
5.17459


112
911C5842D
4.65718


113
96C15DF1C
4.94826


114
00CFD0B2C
5.62084


115
70521DF64
4.77778


116
E65CD0954
4.43697


117
E101D5264
4.24182


118
770F18454
6.37234


119
B3EADAF9C
4.46408


120
256457BAC
5.23129


121
22B95209C
5.9557


122
B4379F6AC
5.1374


123
C4AA120E4
5.35576


124
5224DF4D4
4.82596


125
55F9DAFE4
4.43697


126
C3F757BD4
4.74343









Next, when the number Nt of the transmit antennas is four and the number of the FFT operation points used in the OFDM communication system is 512 (i.e. Nt=4, NFFT=512), R(r) can be expressed by Equation (11) below.




  
    
      
        
          
            R
            ⁡
            
              (
              r
              )
            
          
          =
          
            
              B
              
                IDcell
                
                  +
                  1
                
              
            
            ⁢
            
              g
              
                ∏
                
                  (
                  r
                  )
                
              
            
          
        
        ,
        
          r
          =
          
            
              
                8
                *
                
                  ⌊
                  
                    m
                    9
                  
                  ⌋
                
              
              +
              
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
            
            =
            0
          
        
        ,
        1
        ,
        ...
        ⁢
        
          
        
        ,
        95
      
    
    
      
        (
        11
        )
      
    
  




In Equation (11), the block code generator matrix G is expressed as by Equation (12) below and the interleaving scheme can be expressed by Table 11 below.




  
    
      
        Equation
        ⁢
        
          
        
        ⁢
        
          (
          12
          )
        
      
    
    
      
        
      
    
  
  
    
      
        
          
            
              G
              =
              
              ⁢
              
                [
                
                  
                    g
                    0
                  
                  ⁢
                  
                    
                  
                  ⁢
                  
                    g
                    1
                  
                  ⁢
                  
                    
                  
                  ⁢
                  ...
                  ⁢
                  
                    
                  
                  ⁢
                  
                    g
                    95
                  
                
                ]
              
            
          
        
        
          
            
              =
              
              ⁢
              
                [
                
                  
                    
                      010101010101010100010001000100010000010101100011000000110101011000000000111111110000111100001111
                    
                  
                  
                    
                      001100110011001101010101010101010001000100010001000001010110001100000011010101100000000011111111
                    
                  
                  
                    
                      000011110000111100110011001100110101010101010101000100010001000100000101011000110000001101010110
                    
                  
                  
                    
                      000000001111111100001111000011110011001100110011010101010101010100010001000100010000010101100011
                    
                  
                  
                    
                      000000110101011000000000111111110000111100001111001100110011001101010101010101010001000100010001
                    
                  
                  
                    
                      000001010110001100000011010101100000000011111111000011110000111100110011001100110101010101010101
                    
                  
                  
                    
                      000100010001000100000101011000110000001101010110000000001111111100001111000011110011001100110011
                    
                  
                
                ]
              
            
          
        
      
    
    
      
        (
        12
        )
      
    
  














TABLE 11









Π(l)
2, 6, 0, 10, 14, 11, 7, 3, 8, 15, 1, 12, 9, 4, 13, 5, 18, 26,




24, 17, 29, 19, 21, 16, 23, 22, 25, 28, 27, 31, 20, 30,




41, 34, 38, 44, 36, 43, 35, 32, 45, 47, 46, 39, 40, 33, 37,




42, 60, 56, 59, 61, 51, 62, 52, 49, 58, 48, 53, 50, 54, 57,




55, 63, 71, 77, 76, 74, 67, 66, 68, 75, 78, 64, 69, 79, 72,




70, 65, 73, 81, 92, 83, 87, 82, 94, 86, 88, 95, 91, 93, 90,




84, 85, 80, 89










T(k) in Equation (7) has values as expressed by the hexadecimal numbers shown in Table 12 below and qIDcell[m] can be expressed by the hexadecimal numbers as shown in Tables 13a and 13b.









TABLE 12





ID cell
sequence
papr

















0
CB3
6.26336


1
D47
5.27748


2
59D
4.9581


3
F21
5.05997


4
87E
6.51422


5
BFA
5.33856


6
4D4
7.0618


7
3E0
6.41769


8
3E4
4.87727


9
6F7
4.15136


10
8D0
5.86359


11
33E
5.68455


12
CA3
5.79482


13
119
5.29216


14
AA3
5.3423


15
EC5
5.40257


16
A08
5.63148


17
96C
5.44285


18
9D3
5.19112


19
5BC
5.41859


20
4BC
5.96539


21
D15
6.07706


22
A31
4.76142


23
4B3
4.67373


24
B0A
5.24324


25
BB7
4.81109


26
245
4.99566


27
834
4.81878


28
A59
5.78273


29
B07
5.59368


30
694
5.53837


31
6C6
6.42782


32
1F3
5.26429


33
573
4.94488


34
07F
6.36319


35
9A3
5.91188


36
C86
5.36258


37
349
4.98064


38
C83
6.14253


39
EE0
5.95156


40
4CA
5.40169


41
634
4.82317


42
360
5.05168


43
7B6
5.20885


44
4A7
5.52378


45
0D4
6.47369


46
523
5.20757


47
F29
5.0776


48
A67
5.52381


49
251
5.10732


50
B8E
4.77121


51
5B0
5.38618


52
B6B
5.20069


53
DCC
6.18175


54
356
5.46713


55
7FB
6.23427


56
C6B
4.64117


57
956
5.81606


58
100
5.04293


59
DF0
6.56931


60
663
5.4996


61
602
5.72958


62
894
4.96955


63
247
5.37554


64
73E
5.29366


65
0FE
6.62956


66
5CB
4.88939


67
C59
4.30678


68
5B5
5.54517


69
E2D
5.27261


70
5F6
5.03828


71
9A9
5.25379


72
BDB
5.14859


73
AE7
5.39255


74
2C2
4.97124


75
6A3
6.20876


76
D3A
4.83271


77
741
5.5686


78
737
5.64126


79
7AC
5.17063


80
79F
5.0828


81
3FA
5.22885


82
99C
6.01707


83
755
6.51422


84
A44
4.93486


85
F67
4.86142


86
4D4
6.21941


87
810
4.25677


88
201
4.47647


89
054
6.8165


90
654
5.87238


91
F34
5.31419


92
4FF
6.88515


93
4AA
6.75475


94
E8D
6.10937


95
944
4.79898


96
478
4.77121


97
17E
5.66118


98
696
4.93494


99
31A
5.36534


100
9D7
4.78933


101
2A4
5.45932


102
35C
6.40963


103
CBD
5.39788


104
44C
4.38835


105
416
4.38145


106
6B6
5.5007


107
E79
5.6706


108
34F
5.62588


109
DC4
5.29578


110
586
5.00808


111
DF3
4.48385


112
F2B
5.53794


113
ED1
5.58523


114
686
5.71655


115
500
5.01001


116
8FB
5.89436


117
CB5
5.25553


118
99A
5.47731


119
43D
5.4871


120
161
6.18899


121
32D
5.35874


122
49D
5.46312


123
8BD
5.13605


124
2E9
5.70272


125
0F0
6.26171


126
144
5.50515





















TABLE 13a





ID cell
sequence
papr
ID cell
sequence
papr




















0
07B5CI11880898D2ID714C95B59
6.26336
64
0015DIA53246IB03179396DA2F8
5.29366


1
DFA04795906284114EC142DI7E3
5.27748
65
D80017012A2F07C2452398DEE42
6.62956


2
D815C68418691BC153B08E44CBB
4.9581
66
DF35D610B22C9F105852D40B71B
4.88939


3
4AABF139B866B0A2069058858C3
5.05997
67
4D8BE18D022337710D72828A163
4.30678


4
4D9E300820652C721BE1945039A
6.51422
68
4A3E609C9A28ABA311034E5F83B
5.54517


5
958BB6AC380C34B349519AI4F20
5.33856
69
92ABE638824IB36242B3C05B481
5.27261


6
923E779DA00FAC61552056CI478
7.0618
70
951E67091A4A2FB25FC20CCEFD8
5.03828


7
IC6D02BAF66B8CE64E89080512A
6.41769
71
1BCD120E5C2E0B37446BD20A88B
5.25379


8
1B5883AB7E68143652F844D0872
4.87727
72
1CF8933FD42D97E5591A9E9F3D3
5.14859


9
C34D452F66090CF70148AD46C9
4.15136
73
C4EDI5BBCC4C8F260AAA10DBF69
5.39255


10
C4F8841EEE0A94251D390601D90
5.86359
74
C35894AA444F17F416DB5C0E630
4.97124


11
5646B3A35E0538464919D0C0BE8
5.68455
75
5166E337E448BB9742FB0A8F249
6.20876


12
51F37292C60EA09654681C152B1
5.79482
76
56D362067C4323475F8AC61AB10
4.83271


13
8966B416DE67B85507D89211C0B
5.29216
77
BE46E4A274223F840C3A481E5AB
5.5686


14
8ED33527466C20871AA95E84753
5.3423
78
897365B3FC2IA3561I4B04CBEF3
5.64126


15
4E855A27A38F94B136C919CC181
5.40257
79
49254AB319CA13623C2BC3C3820
5.17063


16
49B09B362B8408612AB8D5198D8
5.63148
80
4E10CBA291C98BB0215A8F56379
5.0828


17
91A51D9233E514A27808DB5D462
5.44285
81
96050D2699A8977373EA81I2FC2
5.22885


18
96909C83BBEE8C7065791788F3B
5.19112
82
91B08C1711AB0BA16F9BCDC749A
6.01707


19
042EEB1E1BE920133159C149942
5.41859
83
030EFBAAB1A4A7C038BB1B460E3
6.51422


20
031B6A0F83EAB8C32D288DDC01A
5.96539
84
04BB3ABB29A73F1026CA57D39BA
4.93486


21
DB8EEC8B9B83A0007F9803D8CA1
6.07706
85
DCAEFC3F31C627D3747A59D7701
4.86142


22
DC882DBA038038D263E94F0D5F9
4.76142
86
DB1B7D0EA9CDBF01690B1542C58
6.21941


23
5268589D45EC1857794011892AB
4.67373
87
55C80809EFA19B8473A24B8690A
4.25677


24
55DD99ACDDE780856431DD1CBF2
5.24324
88
527D893867A203546ED30713053
4.47647


25
8DC81F28D58E984637815358749
4.81109
89
8A680F9C6FC31F953D630957CE8
6.8165


26
8A7D9E394D8504942AF01FCDC11
4.99566
90
8D5DCEADE7C08745211245C25B0
5.87238


27
18C3A984ED82A8F77FD0494C868
4.81878
91
1FE3F93057C72B26753213431C8
5.31419


28
1FF628B56581342563A18599131
5.78273
92
18567801CFCCB7F66943DFD6A91
6.88515


29
C7E3AE116DE028E430110BDDF8B
5.59368
93
C043FE85C7ADAB373AF3D19262A
6.75475


30
C0566F20E5EBB0342D6047484D2
5.53837
94
C7F67FB44FAE33E526829D47D73
6.10937


31
1A24C23D294F4E58569D4A6C3CA
6.42782
95
1D8492899302CD895C7F106386A
4.79898


32
1D11030CB14CD68A4BEC06B9A93
5.26429
96
1A3153980B01555B410EDC86132
4.77121


33
C504C588B925CE4B195C08BD629
4.94488
97
C224951C13604D9A13BED2F2F88
5.66118


34
C23104992126569B052DC468F71
6.36319
98
C511542D8B6BD1480FCF1E676D0
4.93494


35
508F33049129FAFA500D12A9B09
5.91188
99
572F23B03B6479295BEFC8A62A8
5.36534





















TABLE 13b







36
57BAF215092A62284C7C5E7C250
5.36258
100
509AA281B36FE5F9479E0473BF1
4.78933


37
8F2F34B111437EE91ECCD038CEB
4.98064
101
880F2425AB0EF93A142E0A7754A
5.45932


38
889AF5808948E23902BD1CAD7B3
6.14253
102
8F3AA534330565E8095FC6E2C12
6.40963


39
06C9C0A7CF2CC6BE181442290E0
5.95156
103
01E9D0136569416FI3F69866941
5.39788


40
017C4196472F5E6C04658EBCBB8
5.40169
104
065C5102ED62DDBD0E87D4F3018
4.38835


41
D969C7324F4642AF57D500F8502
4.82317
105
DE49D786E503C17C5D375AF7EA2
4.38145


42
DE5C0623D745DE7F4AA44C2DC5A
5.05168
106
D97C56B76D0859AE414616627FA
5.5007


43
4C6271BE774A721E1F841AECA22
5.20885
107
4BC26I2ACD07F5CF1566C0A3183
5.6706


44
4B57F08FEF49EACE02F5567937B
5.52378
108
4C77A03B55046D1D08178C76ADB
5.62588


45
9342360BE728F60D5145587DDC0
6.47369
109
94E2669F5D6D75DC5AA70272460
5.29578


46
9477F71A7F236ADF4C3414A8699
5.20757
110
9357E78ED56EE90C46D64EE7F38
5.00808


47
54A1D83A9AC0DAEB6054D3A004B
5.0776
111
5381C88E308D5D3A6BB609AFBEB
4.48385


48
5394192B02C3463B7C251F75B13
5.52381
112
54B449BFB886C1EA76C7C53A2B3
5.53794


49
8B019FAF0AA25EF82F9511315A9
5.10732
113
8CA1CF3BA0EFDD2925774B3EC09
5.58523


50
8CB41EBE92A9C22832E4DDE4EF0
4.77121
114
8B144E2A28EC41F9380607EB750
5.71655


51
1E0A690332AE6A4B67C40B25888
5.38618
115
192A799798E3E9986C26512AI28
5.01001


52
19BFA832BAA5F69B7AB5C7B03D1
5.20069
116
1E9FB88600E8754A7I579DBFA7I
5.89436


53
C1AA6E96B2CCEE582805C9F4D6A
6.18175
117
C68A7E020889698B23E713FB4CB
5.25553


54
C61FAFA73AC7768835740561632
5.46713
118
C18FBF13908AF1593F96DF2EF92
5.47731


55
484CDAA07CAB560F2FDDDBA5361
6.23427
119
4F6CCA14C6E6D1DE253F81EA8C1
5.4871


56
4FF95B91E4A0CEDF32AC9730A39
4.64117
120
48590B055EE54D0E384E4D3F199
6.18899


57
97EC9D15FCC1D61C611C1974682
5.81606
121
904C8DAI568451CF6AFEC37BD23
5.35874


58
9059IC0474C24ACC7C6D55A1DDA
5.04293
122
97794C90CE8FC9ID778F8FEE47B
5.46312


59
02E76B99D4CDE6AF294D03209A2
6.56931
123
05C73B0D6E88617E23AFD96F003
5.13605


60
0552EAA84CC67E7F343C4FB52F8
5.4996
124
0272BA3CE68BFDAE3EDE95BA95B
5.70272


61
DD476C2C44A762BC668C41B1E40
5.72958
125
DA673C98EEEAE56F6D6E1BBE5E0
6.26171


62
DAF2AD1DCCACFA6C7BFD0D64518
4.96955
126
DD52BD8976E17DBD701F576BCB8
5.50515


63
072010B4AA4587D10AE25A4FBA1
5.37554









As understood from the above description, the present invention provides pilot symbols which can identify cell IDs and sector IDs by using a Walsh code and a block code using Walsh bases and mask sequences in an OFDM communication system, thereby increasing the number of identifiable cell IDs and sector IDs in the OFDM communication system. Further, the present invention enables a receiver to detect a pilot symbol by using an IFHT unit, thereby minimizing the complexity of the receiver. Also, according to the present invention, the pilot symbol is generated by using not only the block code and Walsh code but also the PAPR reduction sequence, thereby improving the PAPR characteristic of the pilot symbol.
While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

## Claims

1. A method for transmitting a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, the method comprising the steps of:
in response to input of the cell identifier, generating, by a block code encoder, a block code corresponding to the cell identifier using a predetermined block code generator matrix;
generating a first part sequence by interleaving, by an interleaver, the block code according to at least one interleaving scheme and performing, by an adder, an exclusive OR operation on the interleaved block code;
selecting a second part sequence corresponding to the cell identifier and from among predetermined sequences considering Peak-to-Average Power Ratio (PAPR) reduction;
generating, by a combiner, a reference signal of a frequency domain by using the first part sequence and the second part sequence;
converting, by a transmitter, the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform (IFFT) operation; and
transmitting, by the transmitter, the reference signal of the time domain in a over a reference signal transmission interval,
wherein the reference signal of the frequency domain is defined by:





  
    
      P
      
        ID
        
          cell
          ,
          S
        
      
    
    ⁡
    
      [
      k
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                
                  
                    
                      2
                    
                    ⁢
                    
                      (
                      
                        1
                        -
                        
                          2
                          ⁢
                          
                            
                          
                          ⁢
                          
                            
                              q
                              
                                ID
                                
                                  cell
                                  ,
                                  S
                                
                              
                            
                            ⁡
                            
                              [
                              m
                              ]
                            
                          
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        2
                        ⁢
                        
                          
                        
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      4
                    
                    -
                    1
                  
                
              
            
            
              
                
                  
                    
                      2
                    
                    ⁢
                    
                      (
                      
                        1
                        -
                        
                          2
                          ⁢
                          
                            
                          
                          ⁢
                          
                            
                              q
                              
                                ID
                                
                                  cell
                                  ,
                                  S
                                
                              
                            
                            ⁡
                            
                              [
                              
                                m
                                -
                                1
                              
                              ]
                            
                          
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        2
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    
                      
                        
                          N
                          used
                        
                        4
                      
                      +
                      1
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      4
                    
                    +
                    2
                  
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      N
                      used
                    
                    2
                  
                
              
            
            
              
                
                  0
                  ,
                
              
              
                otherwise
              
            
          
          ⁢
          
            

          
          ⁢
          
            ID
            cell
          
        
        ∈
        
          {
          
            0
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            126
          
          }
        
      
      ,
      
        s
        ∈
        
          {
          
            0
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            7
          
          }
        
      
      ,
      
        

      
      ⁢
      
        k
        ∈
        
          {
          
            
              
                -
                
                  N
                  FFT
                
              
              /
              2
            
            ,
            
              
                
                  -
                  
                    N
                    FFT
                  
                
                /
                2
              
              +
              1
            
            ,
            ...
            ⁢
            
              
            
            ,
            
              
                
                  N
                  FFT
                
                ⁢
                2
              
              -
              1
            
          
          }
        
      
      ,
    
  



where PIDcell,S[k] denotes the reference signal, IDcell denotes the cell identifier, s denotes a sector identifier, k denotes a sub-carrier index, Nused denotes a number of used subcarriers, NFFT denotes a number of points of the IFFT operation, and qIDcell,S[m] denotes a setup sequence.

2. The method as claimed in claim 1, wherein the step of converting the reference signal comprises the steps of:
inserting null data into sub-carriers corresponding to DC components and intersubcarrier interference eliminating components from among N sub-carriers;
inserting elements of the reference signal into M sub-carriers other than the sub-carriers into which the null data is inserted from among the N sub-carriers; and
performing an IFFI operation on a signal including the reference signal elements and the M sub-carriers and then transmitting the signal.

3. The method as claimed in claim 2, wherein inserting elements of the reference signal is performed in consideration of a predetermined offset that is set to have a specific value for each of the cells and sectors.

4. The method as claimed in claim 1, wherein the setup sequence is defined by:




  
    
      q
      
        
          ID
          cell
        
        ,
        S
      
    
    ⁡
    
      [
      m
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                R
                ⁡
                
                  (
                  
                    
                      8
                      *
                      
                        ⌊
                        
                          m
                          9
                        
                        ⌋
                      
                    
                    +
                    
                      m
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      9
                    
                  
                  )
                
              
              ,
            
          
          
            
              
                
                  where
                  ⁢
                  
                    
                  
                  ⁢
                  m
                  ⁢
                  
                    
                  
                  ⁢
                  mod
                  ⁢
                  
                    
                  
                  ⁢
                  9
                
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              7
            
          
        
        
          
            
              
            
          
          
            
              
                m
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              53
            
          
        
        
          
            
              
                T
                ⁡
                
                  (
                  
                    ⌊
                    
                      m
                      9
                    
                    ⌋
                  
                  )
                
              
              ,
            
          
          
            
              
                where
                ⁢
                
                  
                
                ⁢
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
              =
              8
            
          
        
      
      ,
    
  



wherein └m/9┘ represents a maximum integer not greater than m/9, and R(r) is defined by:





  
    
      
        
          
            R
            ⁡
            
              (
              r
              )
            
          
          =
          
            
              w
              
                r
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                8
              
              s
            
            ⊕
            
              
                b
                
                  IDcell
                  +
                  1
                
              
              ⁢
              
                g
                
                  ∏
                  
                    (
                    r
                    )
                  
                
              
            
          
        
        ,
      
    
  
  
    
      
        
          r
          =
          
            
              
                8
                *
                
                  ⌊
                  
                    m
                    9
                  
                  ⌋
                
              
              +
              
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
            
            =
            0
          
        
        ,
        1
        ,
        ...
        ⁢
        
          
        
        ,
        47
        ,
      
    
  



wherein wsr mod8 represents repetition of Walsh codes having a length of 8, bk (1≦k≦47) represents a k-th row vector of the block code generator matrix, k represents a value calculated by adding a cell identifier IDcell and 1, gu (0≦u ≦47) represents a u-th column vector of the block code generator matrix, u represents indicating an r-th element of an interleaving pattern according to an interleaving scheme Π(r), R(r) denotes a first sequence, and T(−) denotes a second sequence.

5. The method as claimed in claim 4, wherein the block code generator matrix is defined as

6. The method as claimed in claim 5, wherein the interleaving scheme is defined by Π(r) as shown:













Π(r)
9, 7, 14, 15, 10, 1, 2, 5, 3, 8, 0, 4, 13, 11, 6, 12, 27, 29, 21, 18,



16, 25, 23, 17, 24, 19, 28, 31, 26, 20, 30, 22, 38, 47, 41, 42, 37,



46, 39, 45, 32, 34, 40, 33, 35, 43, 36, 44,








wherein each number in the table indicates an index of a sub-carrier to which an element of the block code is one-to-one mapped.

7. An apparatus for transmitting a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, the apparatus comprising:
a block code encoder which, in response to input of the cell identifier, generates a block code corresponding to the cell identifier by using a predetermined block code generator matrix;
an interleaver for interleaving the block code according to at least one interleaving scheme;
an adder for performing an exclusive OR operation on the interleaved block code, thereby generating a first part sequence;
a combiner for generating a reference signal of a frequency domain by using the first part sequence and a second part sequence which is selected corresponding to the cell identifier and from among predetermined sequences; and
a transmitter for converting the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform (IFFT) and, operation and then transmitting the reference signal of the time domain over a reference signal transmission interval,
where the reference signal of the frequency domain is defined by:





  
    
      P
      
        ID
        
          cell
          ,
          S
        
      
    
    ⁡
    
      [
      k
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                
                  
                    
                      2
                    
                    ⁢
                    
                      (
                      
                        1
                        -
                        
                          2
                          ⁢
                          
                            
                          
                          ⁢
                          
                            
                              q
                              
                                ID
                                
                                  cell
                                  ,
                                  S
                                
                              
                            
                            ⁡
                            
                              [
                              m
                              ]
                            
                          
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        2
                        ⁢
                        
                          
                        
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      4
                    
                    -
                    1
                  
                
              
            
            
              
                
                  
                    
                      2
                    
                    ⁢
                    
                      (
                      
                        1
                        -
                        
                          2
                          ⁢
                          
                            
                          
                          ⁢
                          
                            
                              q
                              
                                ID
                                
                                  cell
                                  ,
                                  S
                                
                              
                            
                            ⁡
                            
                              [
                              
                                m
                                -
                                1
                              
                              ]
                            
                          
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        2
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    
                      
                        
                          N
                          used
                        
                        4
                      
                      +
                      1
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      4
                    
                    +
                    2
                  
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      N
                      used
                    
                    2
                  
                
              
            
            
              
                
                  0
                  ,
                
              
              
                otherwise
              
            
          
          ⁢
          
            

          
          ⁢
          
            ID
            cell
          
        
        ∈
        
          {
          
            0
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            126
          
          }
        
      
      ,
      
        s
        ∈
        
          {
          
            0
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            7
          
          }
        
      
      ,
      
        

      
      ⁢
      
        k
        ∈
        
          {
          
            
              
                -
                
                  N
                  FFT
                
              
              /
              2
            
            ,
            
              
                
                  -
                  
                    N
                    FFT
                  
                
                /
                2
              
              +
              1
            
            ,
            ...
            ⁢
            
              
            
            ,
            
              
                
                  N
                  FFT
                
                ⁢
                2
              
              -
              1
            
          
          }
        
      
      ,
    
  



wherein PIDcell,S[k] denotes the reference signal, IDcell denotes the cell identifier, s denotes the sector identifier, k denotes a sub-carrier index, Nused denotes a number of used subcarriers, NFFT denotes a number of points of the IFFT operation, and qIDcell,S[m] denotes a setup sequence.

8. The apparatus as claimed in claim 7, wherein the block code generator matrix includes b number of sub-blocks, each of which includes c number of Walsh bases and d number of mask sequences, and the b sub-blocks including a first sub-block to a b-th sub-block have a relation of cyclic shift between each other, so as to maximize a minimum distance of the block code generated by using the block code generator matrix.

9. The apparatus as claimed in claim 8, wherein the interleaver divides the block code into the b sub-blocks and interleaves the b sub-blocks according to b number of interleaving schemes differently set for the b sub-blocks.

10. The apparatus as claimed in claim 7, wherein the transmitter comprises:
an Inverse Fast Fourier Transform (IFFT) unit for inserting null data into sub-carriers corresponding to DC components and intersubcarrier interference eliminating components from among N sub-carriers, inserting elements of the reference signal into M sub-carriers other than the sub-carriers into which the null data is inserted from among the N sub-carriers, and then performing an IFFT operation on a signal including the reference signal of the frequency domain elements and the M sub-carriers; and
a Radio Frequency (RF) processor for processing and transmitting the IFFT-processed signal.

11. The apparatus as claimed in claim 7, wherein the transmitter comprises:
an IFFT unit for inserting null data into sub-carriers corresponding to DC components and intersubcarrier interference eliminating components from among N sub-carriers, inserting elements of the reference signal into M sub-carriers other than the sub-carriers into which the null data is inserted from among the N sub-carriers, in consideration of a predetermined offset, and then performing an IFFT operation on a signal including the reference signal of the frequency domain elements and the M sub-carriers and then transmitting the signal; and
a Radio Frequency (RF) processor for processing and transmitting the IFFT-processed signal.

12. The apparatus as claimed in claim 11, wherein the offset is set to have a specific value for each of the cells and sectors.

13. The apparatus as claimed in claim 7, wherein the setup sequence is defined by:




  
    
      q
      
        
          ID
          cell
        
        ,
        S
      
    
    ⁡
    
      [
      m
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                R
                ⁡
                
                  (
                  
                    
                      8
                      *
                      
                        ⌊
                        
                          m
                          9
                        
                        ⌋
                      
                    
                    +
                    
                      m
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      9
                    
                  
                  )
                
              
              ,
            
          
          
            
              
                
                  where
                  ⁢
                  
                    
                  
                  ⁢
                  m
                  ⁢
                  
                    
                  
                  ⁢
                  mod
                  ⁢
                  
                    
                  
                  ⁢
                  9
                
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              7
            
          
        
        
          
            
              
            
          
          
            
              
                m
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              53
            
          
        
        
          
            
              
                T
                ⁡
                
                  (
                  
                    ⌊
                    
                      m
                      9
                    
                    ⌋
                  
                  )
                
              
              ,
            
          
          
            
              
                where
                ⁢
                
                  
                
                ⁢
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
              =
              8
            
          
        
      
      ,
    
  



wherein





  ⌊
  
    m
    9
  
  ⌋



 represents a maximum integer not greater than





  
    m
    9
  
  ,



 and R(r) is defined by:





  
    
      
        
          
            R
            ⁡
            
              (
              r
              )
            
          
          =
          
            
              w
              
                r
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                8
              
              s
            
            ⊕
            
              
                b
                
                  IDcell
                  +
                  1
                
              
              ⁢
              
                g
                
                  ∏
                  
                    (
                    r
                    )
                  
                
              
            
          
        
        ,
      
    
  
  
    
      
        
          r
          =
          
            
              
                8
                *
                
                  ⌊
                  
                    m
                    9
                  
                  ⌋
                
              
              +
              
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
            
            =
            0
          
        
        ,
        1
        ,
        ...
        ⁢
        
          
        
        ,
        47
        ,
      
    
  



wherein wsr mod8 represents repetition of Walsh codes having a length of 8, bk (1≦k≦47) represents a k-th row vector of the block code generator matrix, k represents a value calculated by adding a cell identifier IDcell and 1, gu (0≦u≦47) represents a u-th column vector of the block code generator matrix, u represents indicating an r-th element of an interleaving pattern according to an interleaving scheme Π(r), R(r) denotes a first sequence, and T(−) denotes a second sequence.

14. The apparatus as claimed in claim 13, wherein the block code generator matrix is expressed as

15. The apparatus as claimed in claim 14, wherein the interleaving scheme is defined as Π(r) as shown:













Π(r)
9, 7, 14, 15, 10, 1, 2, 5, 3, 8, 0, 4, 13, 11, 6, 12, 27, 29, 21, 18,



16, 25, 23, 17, 24, 19, 28, 31, 26, 20, 30, 22, 38, 47, 41, 42, 37,



46, 39, 45, 32, 34, 40, 33, 35, 43, 36, 44,








wherein each number in the table indicates an index of a sub-carrier to which an element of the block code is one-to-one mapped.

16. A method for receiving a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, the method comprising:
extracting, by a reference signal extractor, the reference signal from a received signal which has been converted through a Fast Fourier Transform (FFT) operation;
dividing, by an adder, the reference signal into a predetermined number of intervals and performing an exclusive OR (XOR) operation on the divided intervals;
deinterleaving, by a deinterleaver, the XOR-processed signal according to at least one deinterleaving scheme;
dividing, by a sub-block divider, the deinterleaved signal into sub-block signals in accordance with a predetermined block code generator matrix;
performing, by a block code decoder, an Inverse Fast Hadamard Transform (IFHT) using mask sequences generated according to control of each of the sub-block signals;
generating, by a combiner, a combined signal by combining the IFHT-processed signals for each of the sub-block signals; and
determining, by a comparison selector, a cell identifier corresponding to a block code having a maximum correlation value from among the combined signals as a final cell identifier,
wherein the reference signal of the frequency domain is defined by:





  
    
      P
      
        ID
        
          cell
          ,
          S
        
      
    
    ⁡
    
      [
      k
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                
                  
                    
                      2
                    
                    ⁢
                    
                      (
                      
                        1
                        -
                        
                          2
                          ⁢
                          
                            
                          
                          ⁢
                          
                            
                              q
                              
                                ID
                                
                                  cell
                                  ,
                                  S
                                
                              
                            
                            ⁡
                            
                              [
                              m
                              ]
                            
                          
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        2
                        ⁢
                        
                          
                        
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      4
                    
                    -
                    1
                  
                
              
            
            
              
                
                  
                    
                      2
                    
                    ⁢
                    
                      (
                      
                        1
                        -
                        
                          2
                          ⁢
                          
                            
                          
                          ⁢
                          
                            
                              q
                              
                                ID
                                
                                  cell
                                  ,
                                  S
                                
                              
                            
                            ⁡
                            
                              [
                              
                                m
                                -
                                1
                              
                              ]
                            
                          
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        2
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    
                      
                        
                          N
                          used
                        
                        4
                      
                      +
                      1
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      4
                    
                    +
                    2
                  
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      N
                      used
                    
                    2
                  
                
              
            
            
              
                
                  0
                  ,
                
              
              
                otherwise
              
            
          
          ⁢
          
            

          
          ⁢
          
            ID
            cell
          
        
        ∈
        
          {
          
            0
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            126
          
          }
        
      
      ,
      
        s
        ∈
        
          {
          
            0
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            7
          
          }
        
      
      ,
      
        

      
      ⁢
      
        k
        ∈
        
          {
          
            
              
                -
                
                  N
                  FFT
                
              
              /
              2
            
            ,
            
              
                
                  -
                  
                    N
                    FFT
                  
                
                /
                2
              
              +
              1
            
            ,
            ...
            ⁢
            
              
            
            ,
            
              
                
                  N
                  FFT
                
                ⁢
                2
              
              -
              1
            
          
          }
        
      
      ,
    
  



wherein PIDcell,S[k] denotes the reference signal, IDcell denotes the cell identifier, s denotes the sector identifier, k denotes a sub-carrier index, Nused denotes a number of subcarriers used, NFFT denotes a number of points of the IFFT operation, and qIDcell,S[m] denotes a setup sequence.

17. The method as claimed in claim 16, wherein, in the step of extracting, the reference signal is extracted by eliminating a predetermined sequence from a signal received through M sub-carriers other than sub-carriers corresponding to DC components and intersubcarrier interference eliminating components from among N sub-carriers.

18. The method as claimed in claim 17, wherein the eliminating is performed in consideration of a predetermined offset that is set to have a specific value for each of the cells and sectors.

19. The method as claimed in claim 16, wherein the setup sequence is defined by:




  
    
      q
      
        
          ID
          cell
        
        ,
        S
      
    
    ⁡
    
      [
      m
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                R
                ⁡
                
                  (
                  
                    
                      8
                      *
                      
                        ⌊
                        
                          m
                          9
                        
                        ⌋
                      
                    
                    +
                    
                      m
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      9
                    
                  
                  )
                
              
              ,
            
          
          
            
              
                
                  where
                  ⁢
                  
                    
                  
                  ⁢
                  m
                  ⁢
                  
                    
                  
                  ⁢
                  mod
                  ⁢
                  
                    
                  
                  ⁢
                  9
                
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              7
            
          
        
        
          
            
              
            
          
          
            
              
                m
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              53
            
          
        
        
          
            
              
                T
                ⁡
                
                  (
                  
                    ⌊
                    
                      m
                      9
                    
                    ⌋
                  
                  )
                
              
              ,
            
          
          
            
              
                where
                ⁢
                
                  
                
                ⁢
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
              =
              8
            
          
        
      
      ,
    
  



wherein





  ⌊
  
    m
    9
  
  ⌋



 represents a maximum integer not greater than





  
    m
    9
  
  ,



 and R(r) is defined by:





  
    
      
        
          
            R
            ⁡
            
              (
              r
              )
            
          
          =
          
            
              w
              
                r
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                8
              
              s
            
            ⊕
            
              
                b
                
                  IDcell
                  +
                  1
                
              
              ⁢
              
                g
                
                  ∏
                  
                    (
                    r
                    )
                  
                
              
            
          
        
        ,
      
    
  
  
    
      
        
          r
          =
          
            
              
                8
                *
                
                  ⌊
                  
                    m
                    9
                  
                  ⌋
                
              
              +
              
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
            
            =
            0
          
        
        ,
        1
        ,
        ⋯
        ⁢
        
          
        
        ,
        47
        ,
      
    
  



wherein wsr mod8 represents repetition of Walsh codes having a length of 8, bk (1≦k≦47) represents a k-th row vector of the block code generator matrix, k represents a value calculated by adding a cell identifier IDcell and ‘1’, gu (0≦u≦47) represents a u-th column vector of the block code generator matrix, u represents indicating an r-th element of an interleaving pattern according to a deinterleaving scheme Π(r), R(r) denotes a first sequence, and T(−) denotes a second sequence.

20. The method as claimed in claim 19, wherein the block code generator matrix is defined as:

21. The method as claimed in claim 20, wherein the deinterleaving scheme is defined to correspond to an interleaving scheme Π(r) as shown in:













Π(r)
9, 7, 14, 15, 10, 1, 2, 5, 3, 8, 0, 4, 13, 11, 6, 12, 27, 29, 21, 18,



16, 25, 23, 17, 24, 19, 28, 31, 26, 20, 30, 22, 38, 47, 41, 42, 37,



46, 39, 45, 32, 34, 40, 33, 35, 43, 36, 44,








wherein each number in the table indicates an index of a sub-carrier to which an element of the block code is one-to-one mapped.

22. The method as claimed in claim 21, wherein the setup sequence is set to have a minimum Peak to Average Power Ratio (PAPR) for the reference signal.

23. An apparatus for receiving a reference signal for identification of each cell in a communication system including a plurality of cells each of which is identified by a cell identifier, the apparatus comprising:
a Fast Fourier Transform (FFT) unit for performing an FFT operation on a received signal;
a reference signal extractor for extracting the reference signal from the FFT-processed signal;
an adder for dividing the reference signal into a predetermined number of intervals and performing an exclusive OR (XOR) operation on the divided intervals;
a deinterleaver for deinterleaving the XOR-processed signal according to at least one deinterleaving scheme;
a sub-block divider for dividing the deinterleaved signal into sub-block signals in accordance with a predetermined block code generator matrix;
a block code decoder for performing an Inverse Fast Hadamard Transform (IFHT) using mask sequences generated according to control of each of the sub-block signals;
a combiner for generating a combined signal by combining the IFHT-processed signals for each of the sub-block signals; and
a comparison selector for determining a cell identifier corresponding to a block code having a maximum correlation value from among the combined signals as a final cell identifier,
wherein the reference signal of the frequency domain is defined by:





  
    
      P
      
        ID
        
          cell
          ,
          S
        
      
    
    ⁡
    
      [
      k
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                
                  
                    
                      2
                    
                    ⁢
                    
                      (
                      
                        1
                        -
                        
                          2
                          ⁢
                          
                            
                          
                          ⁢
                          
                            
                              q
                              
                                ID
                                
                                  cell
                                  ,
                                  S
                                
                              
                            
                            ⁡
                            
                              [
                              m
                              ]
                            
                          
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        2
                        ⁢
                        
                          
                        
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      4
                    
                    -
                    1
                  
                
              
            
            
              
                
                  
                    
                      2
                    
                    ⁢
                    
                      (
                      
                        1
                        -
                        
                          2
                          ⁢
                          
                            
                          
                          ⁢
                          
                            
                              q
                              
                                ID
                                
                                  cell
                                  ,
                                  S
                                
                              
                            
                            ⁡
                            
                              [
                              
                                m
                                -
                                1
                              
                              ]
                            
                          
                        
                      
                      )
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        2
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    
                      
                        
                          N
                          used
                        
                        4
                      
                      +
                      1
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      4
                    
                    +
                    2
                  
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      N
                      used
                    
                    2
                  
                
              
            
            
              
                
                  0
                  ,
                
              
              
                otherwise
              
            
          
          ⁢
          
            

          
          ⁢
          
            ID
            cell
          
        
        ∈
        
          {
          
            0
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            126
          
          }
        
      
      ,
      
        s
        ∈
        
          {
          
            0
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            7
          
          }
        
      
      ,
      
        

      
      ⁢
      
        k
        ∈
        
          {
          
            
              
                -
                
                  N
                  FFT
                
              
              /
              2
            
            ,
            
              
                
                  -
                  
                    N
                    FFT
                  
                
                /
                2
              
              +
              1
            
            ,
            ...
            ⁢
            
              
            
            ,
            
              
                
                  N
                  FFT
                
                ⁢
                2
              
              -
              1
            
          
          }
        
      
      ,
    
  



where PIDcell,S[k] denotes the reference signal of the frequency domain, IDcell denotes the cell identifier, s denotes the sector identifier, k denotes a sub-carrier index, Nused denotes a number of used subcarriers, NFFT denotes a number of points of the FFT operation, and qIDcell,S[m] denotes a setup sequence.

24. The apparatus as claimed in claim 23, wherein the reference signal extractor extracts the reference signal by eliminating a predetermined sequence from a signal received through M sub-carriers other than sub-carriers corresponding to DC components and intersubcarrier interference eliminating components from among N sub-carriers.

25. The apparatus as claimed in claim 24, wherein the eliminating is performed in consideration of a predetermined offset that is set to have a specific value for each of the cells and sectors.

26. The apparatus as claimed in claim 23, wherein the setup sequence is defined by:




  
    
      q
      
        
          ID
          cell
        
        ,
        S
      
    
    ⁡
    
      [
      m
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                R
                ⁡
                
                  (
                  
                    
                      8
                      *
                      
                        ⌊
                        
                          m
                          9
                        
                        ⌋
                      
                    
                    +
                    
                      m
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      9
                    
                  
                  )
                
              
              ,
            
          
          
            
              
                
                  where
                  ⁢
                  
                    
                  
                  ⁢
                  m
                  ⁢
                  
                    
                  
                  ⁢
                  mod
                  ⁢
                  
                    
                  
                  ⁢
                  9
                
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              7
            
          
        
        
          
            
              
            
          
          
            
              
                m
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              53
            
          
        
        
          
            
              
                T
                ⁡
                
                  (
                  
                    ⌊
                    
                      m
                      9
                    
                    ⌋
                  
                  )
                
              
              ,
            
          
          
            
              
                where
                ⁢
                
                  
                
                ⁢
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
              =
              8
            
          
        
      
      ,
    
  



wherein





  ⌊
  
    m
    9
  
  ⌋



 represents a maximum integer not greater than





  
    m
    9
  
  .



 and R(r) is defined by:





  
    
      
        
          
            R
            ⁡
            
              (
              r
              )
            
          
          =
          
            
              w
              
                r
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                8
              
              s
            
            ⊕
            
              
                b
                
                  IDcell
                  +
                  1
                
              
              ⁢
              
                g
                
                  ∏
                  
                    (
                    r
                    )
                  
                
              
            
          
        
        ,
      
    
  
  
    
      
        
          r
          =
          
            
              
                8
                *
                
                  ⌊
                  
                    m
                    9
                  
                  ⌋
                
              
              +
              
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
            
            =
            0
          
        
        ,
        1
        ,
        ...
        ⁢
        
          
        
        ,
        47
        ,
      
    
  



wherein wsr mod8 represents repetition of Walsh codes having a length of 8, bk (1≦k≦47) represents a k-th row vector of the block code generator matrix, k represents a value calculated by adding a cell identifier IDcell and ‘1’, gu (0≦u ≦47) represents a u-th column vector of the block code generator matrix, u represents indicating an r-th element of an interleaving pattern according to a deinterleaving scheme Π(r), R(r) denotes a first sequence, and T(−) denotes a second sequence.

27. The apparatus as claimed in claim 23, wherein the block code generator matrix is defined as:

28. The apparatus as claimed in claim 27, wherein the deinterleaving scheme corresponds to an interleaving scheme Π(r) as shown in:













Π(r)
9, 7, 14, 15, 10, 1, 2, 5, 3, 8, 0, 4, 13, 11, 6, 12, 27, 29, 21, 18,



16, 25, 23, 17, 24, 19, 28, 31, 26, 20, 30, 22, 38, 47, 41, 42, 37,



46, 39, 45, 32, 34, 40, 33, 35, 43, 36, 44,








wherein each number in the table indicates an index of a sub-carrier to which an element of the block code is one-to-one mapped.

29. The apparatus as claimed in claim 28, wherein the setup sequence is set to have a minimum Peak to Average Power Ratio (PAPR) for the reference signal.

30. A method for transmitting a reference signal for identification of each cell through at least one transmit antenna in a communication system including a plurality of cells each of which is identified by a cell identifier, the method comprising:
receiving a cell identifier;
generating, by a block code encoder, a block code corresponding to the cell identifier by using a predetermined block code generator matrix;
selecting a Walsh code corresponding to the cell identifier from among predetermined Walsh codes, and repeating the selected Walsh code a predetermined number of times;
interleaving, by an interleaver, the block code according to at least one interleaving scheme and performing, by an adder, an exclusive OR operation on the interleaved block code and the repeated Walsh code, thereby generating a first part sequence;
selecting a second part sequence corresponding to the cell identifier from among predetermined sequences;
generating, by a combiner, a reference signal of a frequency domain by using the first part sequence and the second part sequence; and
converting, by a transmitter, the reference signal of the frequency domain to a reference signal of a time domain through an Inverse Fast Fourier Transform (IFFT) operation and then transmitting the reference signal of the time domain in a predetermined reference signal transmission interval,
wherein the reference signal of the frequency domain is defined by:





  
    
      
        
          
            P
            
              ID
              
                cell
                ,
                n
              
            
          
          ⁡
          
            [
            k
            ]
          
        
        =
        
          {
          
            
              
                
                  
                    1
                    -
                    
                      2
                      ⁢
                      
                        
                          q
                          
                            ID
                            cell
                          
                        
                        ⁡
                        
                          [
                          m
                          ]
                        
                      
                    
                  
                  ,
                
              
              
                
                  
                    k
                    =
                    
                      
                        
                          N
                          t
                        
                        ⁢
                        m
                      
                      -
                      
                        
                          N
                          used
                        
                        2
                      
                      +
                      n
                    
                  
                  ,
                
              
            
            
              
                
                  
                
              
              
                
                  
                    m
                    =
                    0
                  
                  ,
                  1
                  ,
                  ...
                  ⁢
                  
                    
                  
                  ,
                  
                    
                      
                        N
                        used
                      
                      
                        N
                        t
                      
                    
                    -
                    1
                  
                
              
            
            
              
                
                  0
                  ,
                
              
              
                otherwise
              
            
          
        
      
    
  
  
    
      
        
          
            ID
            cell
          
          ∈
          
            {
            
              0
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              126
            
            }
          
        
        ,
        
          n
          =
          0
        
        ,
        1
        ,
        
          
            ...
            ⁢
            
              
            
            ⁢
            
              N
              t
            
          
          -
          1
        
        ,
      
    
  
  
    
      
        
          k
          ∈
          
            {
            
              
                -
                
                  
                    N
                    FFT
                  
                  2
                
              
              ,
              
                
                  -
                  
                    
                      N
                      FFT
                    
                    2
                  
                
                +
                1
              
              ,
              ...
              ⁢
              
                
              
              ,
              
                
                  
                    N
                    FFT
                  
                  2
                
                -
                1
              
            
            }
          
        
        ,
      
    
  



where PIDcell,S[k] denotes the reference signal, IDcell denotes the cell identifier, n denotes an index of one of the transmit antennas, k denotes a sub-carrier index, NFFT denotes a number of points of the IFFT operation, Nused denotes a number of used subcarriers, Nt indicates a number of the transmit antennas, and qIDcell,S[m] denotes a setup sequence.

31. The method as claimed in claim 30, wherein the block code generator matrix includes b number of sub-blocks, each of which includes c number of Walsh bases and d number of mask sequences.

32. The method as claimed in claim 31, wherein the b sub-blocks including a first sub-block to a b-th sub-block have a relation of cyclic shift between each other, so as to maximize the minimum distance of the block code generated by using the block code generator matrix.

33. The method as claimed in claim 31, wherein the step of interleaving comprises the steps of:
dividing the block code into the b sub-blocks; and
interleaving the b sub-blocks according to b number of interleaving schemes differently set for the b sub-blocks.

34. The method as claimed in claim 33, wherein the step of converting comprises the steps of:
inserting null data into sub-carriers corresponding to DC components and intersubcarrier interference eliminating components from among N sub-carriers;
inserting elements of the reference signal into M sub-carriers other than the sub-carriers into which the null data is inserted from among the N sub-carriers; and
performing an Inverse Fast Fourier Transform (IFFT) operation on a signal including the reference signal elements and the M sub-carriers.

35. The method as claimed in claim 33, wherein the step of converting comprises the steps of:
inserting null data into sub-carriers corresponding to DC components and intersubcarrier interference eliminating components from among N sub-carriers;
inserting elements of the reference signal into M sub-carriers other than the sub-carriers into which the null data is inserted from among the N sub-carriers, in consideration of a predetermined offset; and
performing an IFFT operation on a signal including the reference signal elements and the M sub-carriers and then transmitting the signal.

36. The method as claimed in claim 35, wherein the offset is set to have a specific value for each of the cells and sectors.

37. The method as claimed in claim 30, wherein the setup sequence is defined by:




  
    
      q
      
        ID
        cell
      
    
    ⁡
    
      [
      m
      ]
    
  
  =
  
    {
    
      
        
          
            
              
                R
                ⁡
                
                  (
                  
                    
                      8
                      *
                      
                        ⌊
                        
                          m
                          9
                        
                        ⌋
                      
                    
                    +
                    
                      m
                      ⁢
                      
                        
                      
                      ⁢
                      mod
                      ⁢
                      
                        
                      
                      ⁢
                      9
                    
                  
                  )
                
              
              ,
            
          
          
            
              
                
                  where
                  ⁢
                  
                    
                  
                  ⁢
                  m
                  ⁢
                  
                    
                  
                  ⁢
                  mod
                  ⁢
                  
                    
                  
                  ⁢
                  9
                
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              7
            
          
        
        
          
            
              
            
          
          
            
              
                m
                =
                0
              
              ,
              1
              ,
              ...
              ⁢
              
                
              
              ,
              
                
                  
                    N
                    used
                  
                  
                    N
                    t
                  
                
                -
                1
              
            
          
        
        
          
            
              
                T
                ⁡
                
                  (
                  
                    ⌊
                    
                      m
                      9
                    
                    ⌋
                  
                  )
                
              
              ,
            
          
          
            
              
                where
                ⁢
                
                  
                
                ⁢
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
              =
              8
            
          
        
      
      ,
    
  



wherein





  ⌊
  
    m
    9
  
  ⌋



 represents a maximum integer not greater than





  
    m
    9
  
  ,



 R(r) denotes a first sequence, and T(−) denotes a second sequence.

38. The method as claimed in claim 37, wherein R(r) is defined by an equation,




  
    
      R
      ⁡
      
        (
        r
        )
      
    
    =
    
      
        B
        
          IDcell
          
            +
            1
          
        
      
      ⁢
      
        g
        
          ∏
          
            (
            r
            )
          
        
      
    
  
  ,
  
    r
    =
    
      
        
          8
          *
          
            ⌊
            
              m
              9
            
            ⌋
          
        
        +
        
          m
          ⁢
          
            
          
          ⁢
          mod
          ⁢
          
            
          
          ⁢
          9
        
      
      =
      0
    
  
  ,
  1
  ,
  ...
  ⁢
  
    
  
  ,
  47
  ,



wherein the number of the transmit antennas is two, the number of operation points of the FFT operation is 128, bk represents a k-th row vector of the block code generator matrix, k represents a value calculated by adding a cell identifier IDcell and 1, gu (0≦u≦47) represents a u-th column vector of the block code generator matrix, and u represents indicating an r-th element of a interleaving pattern according to an interleaving scheme Π(r).

39. The method as claimed in claim 38, wherein the block code generator matrix is defined as:

40. The method as claimed in claim 38, wherein the interleaving scheme is defined by Π(r) as shown in:













Π(l)
5, 6, 4, 10, 7, 2, 14, 0, 8, 11, 13, 12, 3, 15, 1, 9, 26, 29, 19, 27,



31, 17, 20, 16, 23, 28, 24, 21, 18, 30, 25, 22, 43, 46, 34, 47, 44,



41, 37, 36, 39, 38, 35, 33, 32, 45, 40, 42,








wherein each number in the table indicates an index of a sub-carrier to which an element of the block code is one-to-one mapped.

41. The method as claimed in claim 38, wherein T(k) has one of values as expressed in:












ID cell
sequence
papr

















0
1 1 1 0 1 1
6.67057


1
0 0 1 1 0 0
5.883


2
1 1 1 1 1 1
4.95588


3
0 1 1 0 0 1
4.92942


4
1 0 0 1 0 0
4.84232


5
0 1 0 1 0 0
5.97707


6
0 0 0 0 1 1
5.2818


7
0 1 1 1 0 1
4.62935


8
1 1 1 1 0 1
4.80191


9
0 1 1 1 1 0
4.62839


10
1 0 0 0 0 0
4.93818


11
0 0 0 0 1 0
4.62239


12
1 1 0 0 1 1
5.23206


13
0 0 0 0 0 1
4.76556


14
1 1 0 1 1 1
5.21957


15
0 1 1 0 0 0
6.73261


16
0 0 1 1 1 0
4.9981


17
0 1 1 0 0 0
5.23977


18
1 1 1 1 1 0
5.59862


19
0 1 1 1 0 1
6.75846


20
0 0 1 1 1 1
4.86729


21
1 1 0 0 0 0
5.57405


22
1 0 1 0 0 1
4.82309


23
0 1 0 1 0 1
4.54948


24
0 1 1 1 0 1
5.45765


25
1 1 0 0 0 1
4.91648


26
1 0 0 1 0 1
3.95813


27
1 0 0 0 0 1
6.03433


28
1 1 0 0 0 1
4.50629


29
0 1 0 0 0 1
4.80454


30
1 0 1 1 1 1
4.94614


31
1 0 1 1 0 0
4.54236


32
0 1 1 0 0 0
5.66311


33
0 1 1 0 0 0
5.18297


34
1 1 0 1 0 1
5.59197


35
1 0 0 1 0 0
5.51692


36
1 1 0 0 1 0
4.64969


37
1 1 1 0 0 0
5.59862


38
0 0 0 0 1 1
5.56593


39
1 0 1 0 0 0
6.65257


40
0 0 1 0 1 1
6.30837


41
0 0 0 1 0 1
5.76988


42
0 0 0 1 1 1
5.17799


43
1 0 0 1 1 0
5.50595


44
0 0 0 0 0 1
5.58222


45
1 1 1 0 1 1
5.19814


46
1 0 0 1 1 0
5.50865


47
1 0 0 0 0 0
5.40509


48
1 0 0 1 0 0
4.48416


49
0 1 0 0 1 1
5.59862


50
0 1 0 1 0 0
4.76609


51
0 1 1 1 0 1
4.87035


52
1 1 1 0 0 1
5.60052


53
1 0 1 0 0 1
4.18939


54
1 1 1 1 0 1
5.00411


55
1 1 1 1 0 0
4.91284


56
0 0 0 0 1 0
6.92296


57
0 0 0 0 1 0
5.39012


58
0 1 1 0 0 1
6.0232


59
1 1 0 1 0 0
5.27241


60
0 0 1 0 1 0
5.26582


61
1 0 0 0 0 1
5.47146


62
0 0 0 0 1 0
6.43249


63
1 0 0 1 1 1
4.69906


64
1 1 1 0 0 0
5.28969


65
1 0 1 0 1 1
6.66965


66
1 0 1 0 1 1
5.90593


67
0 1 1 1 0 0
6.13642


68
0 0 1 0 0 0
4.9337


69
0 1 1 0 1 0
5.19715


70
1 1 1 1 0 0
5.05877


71
1 0 0 1 0 0
5.42538


72
1 1 1 0 1 0
5.21428


73
1 0 1 1 0 1
4.27288


74
0 1 0 0 0 1
4.63478


75
1 0 1 0 0 1
5.47216


76
1 0 1 0 0 0
6.48514


77
1 1 0 0 0 0
5.95897


78
0 0 0 0 0 1
5.59862


79
0 1 0 0 0 0
5.36634


80
0 0 0 0 1 0
4.79522


81
0 0 1 1 1 0
5.03585


82
1 1 0 0 1 1
6.41538


83
0 1 1 0 0 1
5.92329


84
1 0 1 1 1 0
5.24541


85
0 0 0 0 0 1
6.41868


86
1 0 1 0 1 1
5.47231


87
0 1 0 1 1 1
4.27052


88
0 0 0 1 0 1
4.98455


89
0 0 0 1 0 1
4.85573


90
1 0 1 1 0 0
4.66224


91
0 1 1 0 0 1
5.59862


92
0 1 0 1 0 1
5.13782


93
1 1 0 9 0 0
5.73599


94
0 1 1 1 1 1
6.91115


95
0 1 1 1 0 1
4.76096


96
0 1 0 1 1 1
4.43229


97
1 0 0 1 1 1
4.52951


98
1 0 0 1 0 0
4.16266


99
1 1 1 0 1 0
5.72573


100
0 1 0 1 0 0
4.34746


101
1 0 0 1 0 0
6.81937


102
0 1 0 1 1 1
5.86829


103
0 1 0 1 1 0
5.22098


104
1 0 0 0 0 0
4.8724


105
0 1 1 0 1 1
6.7658


106
1 0 0 0 1 0
5.75267


107
1 1 0 0 1 1
5.1796


108
1 1 1 0 0 0
6.00083


109
1 0 1 0 0 1
4.6724


110
1 0 0 1 0 0
4.8945


111
0 0 1 1 1 0
4.05646


112
0 0 1 1 1 1
5.6271


113
0 1 1 1 1 1
5.59862


114
1 1 0 0 1 0
4.80494


115
0 0 1 1 0 0
5.95286


116
0 1 1 0 0 1
5.99303


117
0 1 0 0 1 1
3.97648


118
0 1 0 1 0 0
5.71222


119
0 0 0 0 1 1
4.61998


120
1 1 1 1 1 0
4.67909


121
1 0 0 1 1 0
5.53328


122
0 0 0 1 1 0
5.20303


123
0 1 1 0 0 0
5.00679


124
1 0 1 1 1 0
4.57847


125
0 1 1 1 0 0
4.79082


126
1 1 0 1 0 0
4.91901.

42. The method as claimed in claim 38, wherein qIDcell[m] has one of values as expressed in:












ID cell
sequence
papr

















0
88B7E232CDC83C
6.67057


1
5E260E301C4620
5.883


2
D691EC22D18E1C
4.95588


3
EA1A5F3245640C
4.92942


4
62ADBD0098A430
4.84232


5
B43C5102592228
5.97707


6
3C0BB31084EA14
5.2818


7
127AEE31B90504
4.62935


8
9ACD4C2374C53C
4.80191


9
4C5CE021B54B20
4.62839


10
C4EB0213688318
4.93818


11
F860B103EC6908
4.62239


12
70D7531121A934
6.23206


13
A646BF13E0272C
4.76556


14
2EF15D013DEF14
5.21957


15
4A30D2BAA965A0
6.73261


16
C20730A874AD98
4.9981


17
1416DCAAA52380
5.23977


18
9CA17EB878EBB8
5.59862


19
A02ACDA8FC01AC
6.75846


20
281D2FBA31C994
4.86729


21
FE8CC398E04788
5.57405


22
76BB21AA2D87B4
4.82303


23
584A7C8B1060A4
4.54948


24
D07DDEB9DDA09C
5.45765


25
06EC729B0C2684
4.91648


26
8EDB9089D1E6BC
3.95813


27
B2D023994504AC
6.03433


28
3AE7C18B88C494
4.50629


29
EC766D8949428C
4.80454


30
64C18FBB948AB4
4.94614


31
9A82B62CDF0708
4.54236


32
1235543E02C730
3.86311


33
C424F83CC34128
5.18297


34
4C935A0E1E8114
5.59137


35
7098A91E9A6300
5.51632


36
F8AF4B0C47AB38
4.64969


37
2EBEE72E862520
5.59862


38
A609051C4BED1C
6.56393


39
88F8183D660208
6.63257


40
004FBA2FABCA34
6.30837


41
D65E160D7A442C
5.76388


42
5E69B41FB78C14
5.17733


43
62E2070F336E00
6.50695


44
EA55A51DEEA63C
5.58222


45
3CC4493F2F2824
5.19814


46
B4F3AB0DF2E818
5.50865


47
D0B224966662A8
5.40503


48
58858684BBA290
4.48416


49
8E146A866A2C8C
5.59862


50
0623C894B7E4B0
4.76609


51
3A287BA43306A4
4.87033


52
B29FD9B6EEC69C
5.60052


53
648E35B42F4084
4.18939


54
ECB9D7A6F280BC
5.00411


55
C2C8CAA7DF67A8
4.91284


56
4A7F289502AF90
6.92296


57
9C6E8497C32988
5.39012


58
145966A50EE1B4
6.0232


59
28D2D5959A03A0
6.27241


60
A06537A747CB98
5.26582


61
76F49B85864584
5.47146


62
FE4339974B8DB8
6.43249


63
08A61410F5BE24
4.69906


64
8091F622287618
5.28969


65
56801A20E9F804
6.66865


66
DEB7B83224383C
5.90593


67
E23C4B22B0D228
6.13642


68
6A0BA9306D1210
4.9337


69
BC1A4532AC9C08
5.13715


70
34ADE720715430
5.05877


71
1ADCBA015CB320
5.42538


72
92EB5833817B18
5.21428


73
44FAB43150F504
4.27288


74
CC4D56038D353C
4.63478


75
F0C6A53309D72C
5.47216


76
78F10721C41710
6.49514


77
AEE0EB03059108
5.35897


78
26570911C85134
5.59862


79
4216C68A4CD380
5.36634


80
CA212498811BB8
4.79522


81
1C3088BA509DA0
5.03585


82
94876A888D5D9C
6.41538


83
A80CD9B809B78C
5.92329


84
20BB3BAAD47FB0
5.24541


85
F62A978805F1AC
6.41868


86
7E9D35BAC83994
5.47231


87
506C689BF5DE84
4.27052


88
D85B8A893816BC
4.98455


89
0E4A268BF990A4
4.85573


90
86FD84B9345098
4.66224


91
BA7677A9A0B28C
5.59862


92
3241D59B7D72B4
5.13782


93
E4D07999ACF4A8
5.73533


94
6C67DBAB713C94
6.31115


95
9224E23C3AB12C
4.76096


96
1A13400EF77914
4.43229


97
CC82AC0C36FF0C
4.52351


98
44B50E1EFB3730
4.16266


99
78BEFD2E6FDD20
5.72573


100
F0095F1CB21518
4.34746


101
2698B31E739300
6.81937


102
AE2F510CBE5B3C
5.86829


103
805E4C0D93BC28
5.22038


104
08E9AE1F4E7410
4.8724


105
DE78423D8FFA0C
6.7858


106
56CFA00F423A30
5.75267


107
6AC4531FC6D824
5.1796


108
E2F3F12D0B1018
6.00083


109
34E21D2FCA9604
4.6724


110
BCD5BF1D175638
4.8345


111
D81430A693DC88
4.05646


112
502392B45E1CB4
5.6271


113
86327EB69F9AAC
5.59862


114
0E85DC84425A90
4.90494


115
320E2FB4D6B080
5.95286


116
BA39CDA60B70BC
5.99303


117
6C286184CAFEA4
3.97648


118
E41FC396173698
5.71222


119
CA6E9E972AD98C
4.61398


120
42D97CA5F719B0
4.67909


121
94C89087369FA8
5.53328


122
1C7F3295FB5F90
5.20303


123
2074C1A56FB580
5.00679


124
A8C323B7B27DB8
4.57847


125
7E52CFB573F3A0
4.79082


126
F6E56D87BE3398
4.91901.

43. The method as claimed in claim 38, wherein the interleaving scheme is defined by Π(r) as shown in:
















Π(l)
11, 4, 12, 15, 0, 13, 5, 6, 14, 8, 10, 9, 1, 3, 2, 7, 16, 20,




31, 26, 22, 30, 27, 23, 19, 18, 17, 25, 21, 29, 24, 28,









wherein each number in the table indicates an index of a sub-carrier to which an element of the block code is one-to-one mapped.

44. The method as claimed in claim 37, wherein R(r) is defined:




  
    
      R
      ⁡
      
        (
        r
        )
      
    
    =
    
      
        b
        
          IDcell
          +
          1
        
      
      ⁢
      
        g
        
          ∏
          
            (
            r
            )
          
        
      
    
  
  ,
  
    r
    =
    
      
        
          8
          *
          
            ⌊
            
              m
              9
            
            ⌋
          
        
        +
        
          m
          ⁢
          
            
          
          ⁢
          mod
          ⁢
          
            
          
          ⁢
          9
        
      
      =
      0
    
  
  ,
  1
  ,
  ...
  ⁢
  
    
  
  ,
  31
  ,



wherein the number of the transmit antennas is three, the number of operation points of the FFT operation is 128, bk represents a k-th row vector of the block code generator matrix, k represents a value calculated by adding a cell identifier IDcell and 1, gu (0≦u≦47) represents a u-th column vector of the block code generator matrix, and u represents indicating an r-th element of a interleaving pattern according to an interleaving scheme Π(r).

45. The method as claimed in claim 44, wherein the block code generator matrix is defined as:




  
    
      
        G
        =
        
          [
          
            
              g
              0
            
            ⁢
            
              
            
            ⁢
            
              g
              1
            
            ⁢
            
              
            
            ⁢
            ...
            ⁢
            
              
            
            ⁢
            
              g
              31
            
          
          ]
        
      
    
  
  
    
      
        =
        
          
            [
            
              
                
                  01010101010101010000010101100011
                
              
              
                
                  00110011001100110001000100010001
                
              
              
                
                  00001111000011110101010101010101
                
              
              
                
                  00000000111111110011001100110011
                
              
              
                
                  00000011010101100000111100001111
                
              
              
                
                  00000101011000110000000011111111
                
              
              
                
                  00010001000100010000001101010110
                
              
            
            ]
          
          .

46. The method as claimed in claim 44, wherein T(k) has one of values as expressed in:












ID cell
sequence
papr

















0
0 0 1 1
4.49505


1
0 1 1 0
4.11454


2
0 1 1 0
5.0206


3
1 1 0 0
5.06895


4
0 0 0 0
4.51602


5
1 0 1 0
4.96176


6
0 0 0 1
4.50134


7
0 1 0 0
5.29586


8
1 1 1 1
5.37387


9
1 0 0 0
4.6668


10
0 1 1 0
6.09482


11
0 0 0 1
6.11344


12
0 0 0 0
5.71868


13
0 0 0 0
4.12233


14
0 1 1 1
4.44864


15
1 0 1 0
4.42172


16
1 0 0 0
4.43697


17
0 1 1 0
5.96559


18
0 0 1 0
5.31882


19
1 1 1 0
5.1578


20
0 0 1 1
4.18834


21
1 1 0 0
5.74259


22
1 0 1 0
6.10238


23
1 1 1 0
4.50063


24
1 0 0 1
4.38448


25
1 1 0 1
4.33171


26
1 0 0 1
6.31759


27
1 1 1 0
6.33599


28
1 1 0 1
4.55537


29
0 1 0 0
4.83803


30
1 0 1 1
4.45342


31
1 0 1 0
5.12448


32
1 0 0 0
4.43697


33
0 0 0 1
4.90907


34
1 0 0 1
3.9985


35
1 0 1 0
6.0206


36
0 0 0 1
5.38301


37
1 0 0 0
3.66487


38
1 0 1 1
4.92205


39
0 1 1 1
5.53843


40
0 1 1 1
5.26838


41
1 1 0 1
5.16959


42
0 1 1 0
5.34282


43
0 0 0 0
5.15133


44
1 0 0 1
4.87551


45
1 1 1 1
4.79443


46
1 0 1 0
5.07783


47
0 0 1 0
4.99682


48
1 0 1 1
5.94242


49
1 0 0 1
4.77698


50
1 0 0 0
5.03657


51
0 0 1 1
4.46604


52
1 0 0 0
5.68568


53
1 1 0 1
5.01898


54
0 1 1 1
4.95591


55
1 0 0 1
5.27862


56
1 1 1 0
6.0317


57
1 0 1 1
4.64379


58
1 1 0 0
5.02863


59
0 0 0 0
6.04332


60
0 0 0 1
4.44083


61
0 1 1 1
5.23739


62
1 0 1 0
6.43278


63
0 1 1 1
4.43697


64
1 0 1 1
4.43697


65
1 1 1 0
4.50516


66
1 0 0 1
4.58929


67
0 1 1 0
4.85849


68
0 0 0 0
5.13149


69
0 0 1 0
4.59563


70
0 1 0 1
4.73083


71
1 0 0 0
4.43697


72
1 0 0 0
4.44072


73
1 0 1 0
5.47799


74
1 1 1 0
4.92135


75
1 0 0 0
5.5708


76
1 0 0 0
4.48634


77
0 0 0 1
5.3005


78
1 0 1 1
5.8947


79
1 1 0 0
5.38806


80
0 0 1 0
4.74777


81
0 1 0 0
4.82428


82
1 0 0 0
4.45469


83
1 0 1 1
5.66832


84
1 1 0 0
4.50856


85
1 0 0 1
4.97946


86
1 0 1 1
4.68484


87
0 1 0 1
4.50907


88
1 0 1 0
5.38228


89
0 0 1 0
5.22999


90
1 1 1 0
5.0672


91
0 1 0 0
5.59042


92
0 1 0 1
4.95926


93
0 0 1 1
3.80828


94
1 0 1 1
5.40268


95
0 0 1 0
5.97897


96
1 0 0 1
3.99109


97
1 0 0 1
5.06574


98
0 0 0 1
6.08269


99
1 0 0 0
4.39827


100
0 0 1 1
4.70382


101
0 1 0 1
4.60731


102
0 1 0 0
5.05357


103
1 0 1 0
3.30653


104
1 0 1 1
4.52546


105
1 1 0 0
5.53041


106
0 1 1 0
6.04148


107
1 0 1 0
4.88727


108
0 0 1 0
5.40024


109
1 1 0 0
4.566


110
0 1 1 1
4.92796


111
1 0 1 1
5.17459


112
0 1 0 1
4.65719


113
1 1 1 0
4.94826


114
1 1 1 0
5.62084


115
0 0 1 0
4.77778


116
0 1 0 0
4.43697


117
0 1 1 0
4.24182


118
0 0 0 0
6.37234


119
1 1 1 0
4.46408


120
0 1 1 0
5.23129


121
1 1 0 0
5.9557


122
0 0 1 0
5.1374


123
1 0 0 0
5.35576


124
0 1 0 0
4.82596


125
1 1 1 0
4.43697


126
1 1 1 0
4.74343.

47. The method as claimed in claim 44, wherein qIDcell[m] has one of values as expressed in:












ID cell
sequence
papr

















0
960E8D691
4.49505


1
9159C8F00
4.11454


2
075D46B90
6.0206


3
77C0C8D78
5.06896


4
E14E05948
4.51602


5
E69300278
4.96176


6
701D8D449
4.50134


7
B4784FD80
5.29586


8
22F6C2BB1
5.37387


9
25AB87080
4.6668


10
B3254A6B0
6.09432


11
C338870F9
6.11344


12
55360A4C8
5.71868


13
526B0FDF8
4.12233


14
C465C2BC9
4.44864


15
85C89B61A
4.42172


16
13C61602A
4.43697


17
141B53B1A
5.96559


18
82159EF2A
5.31882


19
F28853B62
5.1578


20
64069EF53
4.18834


21
63DBDB462
5.74259


22
F5D516252
6.10238


23
31B0D4B9A
4.50063


24
A7BE19DAB
4.38448


25
A0E35C49B
1.33171


26
36ED910AB
6.31759


27
46F05C6E2
6.33599


28
D0FED10D3
4.55537


29
D723D48E2
4.83803


30
41AD19FD3
4.46342


31
12D88DA2E
5.12448


32
84D600C1E
4.45697


33
830B0552F
4.90907


34
15858811F
5.9985


35
659805756
6.0206


36
F31688167
5.39301


37
F4CB8D856
3.66497


38
62C500E67
4.92205


39
A620C27AF
5.53849


40
302E4F39F
5.26838


41
37F34A8AF
5.16959


42
A17DC7E9E
5.34282


43
D1600A8D6
5.15133


44
47EE87CE7
4.87551


45
40V3C27D7
4.79443


46
D6VD0F3E6
5.07783


47
971016E34
4.99682


48
019E9BA05
5.94242


49
06C39E135
4.77698


50
90CD13504
5.03657


51
E0509E34D
4.46604


52
76DE1357C
5.68568


53
718356C4D
5.01898


54
E70DDBA7D
4.95591


55
23E8191B5
5.27862


56
B5E6D4784
6.0317


57
B2BB91EB5
4.64379


58
24B55C884
5.02863


59
542891CCC
6.04332


60
C2261C8FD
4.44083


61
C57B593CD
5.23739


62
53F5947FC
6.43278


63
9002C3E29
4.43697


64
068COEA19
4.43697


65
01D14B328
4.50516


66
97DF86519
4.58929


67
E7424B350
4.35848


68
714C86560
5.13148


69
761183E50
4.59563


70
E01F4E861
4.73083


71
24FA8C1A8
4.43697


72
B2F4O1598
4.44072


73
B5A9O4EA8
5.47799


74
29A7C9A98
1.92135


75
53BA04CD0
5.5708


76
CDB4898E0
4.4934


77
C2698C1D1
5.3005


78
54E7D17E1
5.8947


79
15CA58832
5.38806


80
834495E02
4.74777


81
8419D0532
4.82428


82
12971D102
4.45469


83
628A9074B
5.66892


84
F4845D17A
4.50856


85
F3D91884B
4.97946


86
65D795E7B
4.68484


87
A132575B3
4.50907


88
37BC9A382
2.38228


89
30619FAB2
5.22999


90
A6EP52E82
5.0672


91
D672DF8CA
5.59042


92
407C52CFB
4.95926


93
4721177CB
3.80828


94
D1AF9A3FB
5.40268


95
825A0E606
5.97897


96
14D483037
3.99109


97
138986907
5.06574


98
85070BD37
6.08269


99
F59A8697E
4.39827


100
63140BF4F
4.70382


101
64494E47F
4.60731


102
F247C304E
5.05357


103
36A201B86
3.30653


104
A0AC9CFB7
4.52546


105
A7F1C9486
5.53041


106
317F442B6
6.04148


107
41E2896FE
4.68727


108
D76C042CE
5.40024


109
D0B1419FE
4.566


110
463FCCFCF
4.92796


111
07929521D
5.17459


112
911C5842D
4.65719


113
96C15DF1C
4.94826


114
00CFD0B2C
5.62084


115
70521DF64
4.77778


116
E65CD0954
4.43697


117
E101D5264
4.24182


118
770F18454
6.37234


119
B3EADAF9C
4.46408


120
256457BAC
5.23129


121
22B95209C
5.9557


122
B4379F6AC
5.1374


123
C4AA120E4
5.35576


124
5224DF4D4
4.82596


125
55F9DAFE4
4.43697


126
C3F757BD4
4.74343.

48. The method as claimed in claim 37, wherein R(r) is defined by:




  
    
      R
      ⁡
      
        (
        r
        )
      
    
    =
    
      
        B
        
          IDcell
          
            +
            1
          
        
      
      ⁢
      
        g
        
          ∏
          
            (
            r
            )
          
        
      
    
  
  ,
  
    r
    =
    
      
        
          8
          *
          
            ⌊
            
              m
              9
            
            ⌋
          
        
        +
        
          m
          ⁢
          
            
          
          ⁢
          mod
          ⁢
          
            
          
          ⁢
          9
        
      
      =
      0
    
  
  ,
  1
  ,
  ...
  ⁢
  
    
  
  ,
  95
  ,



wherein the number of the transmit antennas is four, the number of operation points of the FFT operation is 512, bk represents a k-th row vector of the block code generator matrix, k represents a value calculated by adding a cell identifier IDcell and 1, gu (0≦u≦47) represents a u-th column vector of the block code generator matrix, and u represents indicating a r-th element of a interleaving pattern according to the interleaving scheme Π(r).

49. The method as claimed in claim 48, wherein the block code generator matrix is defined as:




  
    
      
        G
        =
        
        ⁢
        
          [
          
            
              g
              0
            
            ⁢
            
              
            
            ⁢
            
              g
              1
            
            ⁢
            
              
            
            ⁢
            ...
            ⁢
            
              
            
            ⁢
            
              g
              95
            
          
          ]
        
      
    
  
  
    
      
        =
        
        ⁢
        
          
            [
            
              
                
                  
                    010101010101010100010001000100010000010101100011000000110101011000000000111111110000111100001111
                  
                
                
                  
                    001100110011001101010101010101010001000100010001000001010110001100000011010101100000000011111111
                  
                
                
                  
                    000011110000111100110011001100110101010101010101000100010001000100000101011000110000001101010110
                  
                
                
                  
                    000000001111111100001111000011110011001100110011010101010101010100010001000100010000010101100011
                  
                
                
                  
                    000000110101011000000000111111110000111100001111001100110011001101010101010101010001000100010001
                  
                
                
                  
                    000001010110001100000011010101100000000011111111000011110000111100110011001100110101010101010101
                  
                
                
                  
                    000100010001000100000101011000110000001101010110000000001111111100001111000011110011001100110011
                  
                
              
              .
            
            ]
          
          .

50. The method as claimed in claim 48, wherein the interleaving scheme is defined by Π(r) as shown in:













Π(l)
2, 6, 0, 10, 14, 11, 7, 3, 8, 15, 1, 12, 9, 4, 13, 5, 18, 26, 24,



17, 29, 19, 21, 16, 23, 22, 25, 28, 27, 31, 20, 30, 41, 34, 38,



44, 36, 43, 35, 32, 45, 47, 46, 39, 40, 33, 37, 42, 60, 56, 59,



61, 51, 62, 52, 49, 58, 48, 53, 50, 54, 57, 55, 63, 71, 77, 76,



74, 67, 66, 68, 75, 78, 64, 69, 79, 72, 70, 65, 73, 81, 92, 83,



87, 82, 94, 86, 88, 95, 91, 93, 90, 84, 85, 80, 89,








wherein each number in the table indicates an index of a sub-carrier to which an element of the block code is one-to-one mapped.

51. The method as claimed in claim 48, wherein T(k) has one of values as expressed in:












ID cell
sequence
papr

















0
CB3
6.26336


1
D47
5.27748


2
59D
4.9581


3
F21
5.05997


4
87E
6.51422


5
BFA
5.33856


6
4D4
7.0618


7
3E0
6.41769


8
3E4
4.87727


9
6F7
4.15136


10
8D0
5.86359


11
33E
5.68455


12
CA3
5.79482


13
119
5.29216


14
AA3
5.3423


15
EC5
5.40257


16
A08
5.63148


17
96C
5.44285


18
9D3
5.19112


19
5BC
5.41859


20
4BC
5.96539


21
D15
6.07706


22
A31
4.76142


23
4B3
4.67373


24
B0A
5.24324


25
BB7
4.81109


26
245
4.99566


27
B34
4.81878


28
A59
5.78273


29
807
5.59368


30
694
5.53837


31
6C6
6.42782


32
1F3
5.26429


33
573
4.94488


34
O7F
6.36319


35
9A3
5.91188


36
C86
5.36258


37
349
4.98064


38
C83
6.14253


39
EE0
5.95156


40
4C4
5.40169


41
634
4.82317


42
360
5.05168


43
7B6
5.20885


44
4A7
5.52378


45
0D4
6.47369


46
523
5.20757


47
F29
5.0776


48
A67
5.52381


49
251
5.10732


50
B8E
4.77121


51
580
5.38618


52
B6B
5.20069


53
DCC
6.18175


54
356
5.46713


55
7FB
6.23427


56
C6B
4.64117


57
956
5.81606


58
100
5.04293


59
DF0
6.56931


60
663
5.4996


61
602
5.72958


62
894
4.96955


63
247
5.37554


64
73E
5.29366


65
0FE
6.62956


66
5CB
4.88939


67
C59
4.30678


68
5B5
5.54517


69
E2D
5.27261


70
5F6
5.03828


71
9A9
5.25379


72
BDB
5.14859


73
AE7
5.39255


74
2C2
4.97124


75
6A3
6.20876


76
D3A
4.83271


77
741
5.5686


78
737
5.64126


79
7AC
5.17063


80
79F
5.0828


81
3F4
5.22885


82
99C
6.01707


83
755
6.51422


84
A44
4.93486


85
F67
4.86142


86
4D4
6.21941


87
810
4.25677


88
201
4.47647


89
054
6.8165


90
654
5.87238


91
F34
5.31419


92
4FF
6.88515


93
4AA
6.75475


94
E8D
6.10937


95
944
4.79898


96
478
4.77121


97
17E
5.66118


98
696
4.93494


99
31A
5.36534


100
9D7
4.78933


101
2A4
5.45932


102
35C
6.40963


103
CBD
5.39788


104
44C
4.38835


105
416
4.38145


106
6B6
5.5007


107
E79
5.6706


108
34F
5.62588


109
DC4
5.29578


110
586
5.00808


111
DF3
4.48385


112
F2B
5.53794


113
ED1
5.58523


114
686
5.71655


115
500
5.01001


116
BFB
5.89436


117
CB5
5.25553


118
99A
5.47731


119
43D
5.4871


120
161
6.18899


121
32D
5.35874


122
49D
5.46312


123
8BD
5.13605


124
2E9
5.70272


125
0F0
6.26171


126
144
5.50515.

52. The method as claimed in claim 48, wherein qIDcell[m] has one of values as expressed in:












ID cell
sequence
papr

















0
07B5C111880B98D21D714C95B59
6.26336


1
DFA04795906284114EC142D17E3
5.27748


2
D815C684186918C153B08E44CBB
4.9581


3
4AABF139B866B0A2069058858C3
5.05997


4
4D9E300820652C721BE1945039A
6.51422


5
958BB6AC380C34B349519A14F20
5.33856


6
923E779DA00FAC61552056C1478
7.0618


7
1C6D02BAF66B8CE64E89080512A
6.41769


8
1B5883AB7E68143652F844D0872
4.87727


9
C34D452F66090CF701484AD46C9
4.15136


10
C4F8841EEE0A94251D390601D90
5.86359


11
5646B3A35E0538464919D0C0BE8
5.68455


12
51F37292C60EA09654681C152B1
5.79482


13
8966B416DE67B85507D89211C0B
5.29216


14
8ED33527466C20871AA95E84753
5.3423


15
4E855A27A38F94B136C919CC181
5.40257


16
49B09B362B8408612AB8D5198D8
5.63148


17
91A51D9233E514A27808DB5D462
5.44285


18
96909C83BBEE8C7065791788F3B
5.19112


19
042EEB1E1BE920133159C149942
5.41859


20
031B6A0F83EAB8C32D288DDC01A
5.96539


21
DB8EEC8B9B83A0007F9803D8CA1
6.07706


22
DCBB2DBA038038D263E94F0D5F9
4.76142


23
5268589D45EC1857794011892AB
4.67373


24
55DD99ACDDE780856431DD1CBF2
5.24324


25
8DC81F28D58E984637815358749
4.81109


26
8A7D9E394D8504942AF01FCDC11
4.99566


27
18C3A984ED82A8F77FD0494C868
4.81878


28
1FF628B56581342563A18599131
5.78273


29
C7E3AE116DE028E430110BDDF8B
5.59368


30
C0566F20E5EBB0342D6047484D2
5.53837


31
1A24C23D294F4E58569D4A6C3CA
6.42782


32
1D11030CB14CD68A4BEC06B9A93
5.26429


33
C504C588B925CE4B195C08BD629
4.94488


34
C23104992126569B052DC468F71
6.36319


35
508F33049129FAFA500D12A9B09
5.91188


36
57BAF215092A62284C7C5E7C250
5.36258


37
8F2F34B111437EE91ECCD038CEB
4.98064


38
889AF5808948E23902BD1CAD7B3
6.14253


39
06C9C0A7CF2CC6BE181442290E0
5.95156


40
017C4196472F5E6C04658EBCBB8
5.40169


41
D969C7324F4642AF57D500F8502
4.82317


42
DE5C0623D745DE7F4AA44C2DC5A
5.05168


43
4C6271BE774A721E1F841AECA22
5.20885


44
4B57F08FEF49EACE02F5567937B
5.52378


45
9342360BE728F60D5145587DDC0
6.47369


46
9477F71A7F236ADF4C3414A8599
5.20757


47
54A1D83A9AC0DAEB6054D3A004B
5.0776


48
5394192B02C3463B7C251F75B13
5.52381


49
8B019FAF0AA25EF82F9511315A9
5.10732


50
8CB41EBE92A9C22832E4DDE4EF0
4.77121


51
1E0A690332AE6A4B67C40B25888
5.38618


52
19BFA832BAA5F69B7AB5C7B03D1
5.20069


53
C1AA6E96B2CCEE582805C9F4D6A
6.18175


54
C61FAFA73AC7768835740561632
5.46713


55
484CDAA07CAB560F2FDDDBA5361
6.23427


56
4FF95B91E4A0CEDF32AC9730A39
4.64117


57
97EC9D15FCC1D61C611C1974682
5.81606


58
90591C0474C24ACC7C6D55A1DDA
5.04293


59
02E76B99D4CDE6AF294D03209A2
6.56931


60
0552EAA84CC67E7F343C4FB52FB
5.4996


61
DD476C2C44A762BC668C41B1E40
5.72958


62
DAF2AD1DCCACFA6C7BFD0D64518
4.96955


63
072010B4AA4587D10AE25A4FBA1
5.37554


64
0015D1A532461B03179396DA2F8
5.29366


65
D80017012A2F07C2452398DEE42
6.62956


66
DF35D610B22C9F105852D40B71B
4.88939


67
4D8BE18D022337710D72828A163
4.30678


68
4A3E609C9A28ABA311034E5F83B
5.54517


69
92ABE6388241B36242B3C05B481
5.27261


70
951E67091A4A2FB25FC20CCEFD8
5.03828


71
1BCD120E5C2E0B37446BD20A88B
5.25379


72
1CF8933FD42D97E5591A9E9F3D3
5.14859


73
C4ED15BBCC4C8F260AAA10DBF69
5.39255


74
C35894AA444F17F416DB5C0E630
4.97124


75
5166E337E448BB9742FB0A8F249
6.20876


76
56D362067C4323475F8AC61AB10
4.83271


77
8E46E4A274223F840C3A481E5AB
5.5686


78
897365B3FC21A356114B04CBEF3
5.64126


79
49254AB319CA13623C2BC3C3820
5.17063


80
4E10CBA291C98BB0215A8F56379
5.0828


81
96050D2699A8977373EA8112FC2
5.22885


82
91B08C1711AB0BA16F9BCDC749A
6.01707


83
030EFBAAB1A4A7C03BBB1B460E3
6.51422


84
04BB3ABB29A73F1026CA57D39BA
4.93486


85
DCAEFC3F31C627D3747A59D7701
4.86142


86
DB1B7D0EA9CDBF01690B1542C58
6.21941


87
55C80809EFA19B8473A24B8690A
4.25677


88
527D893867A203546ED30713053
4.47647


89
8A680F9C6FC31F953D630957CE8
6.8165


90
8D5DCEADE7C08745211245C25B0
5.87238


91
1FE3F93057C72B26753213431C8
5.31419


92
18567801CFCCB7F66943DFD6A91
6.88515


93
C043FE85C7ADAB373AF3D19262A
6.75475


94
C7F67FB44FAE33E526829D47D73
6.10937


95
1D8492899302CD895C7F106386A
4.79898


96
1A3153980B01555B410EDCB6132
4.77121


97
C224951C13604D9A13BED2F2F88
5.66118


98
C511542D8B6BD1480FCF1E676D0
4.93494


99
572F23B03B6479295BEFC8A62A8
5.36534


100
509AA281B36FE5F9479E0473BF1
4.78933


101
880F2425AB0EF93A142E0A7754A
5.45932


102
8F3AA534330565E8095FC6E2C12
6.40963


103
01E9D0136569416F13F69866941
5.39788


104
065C5102ED62DDBD0E87D4F3018
4.38835


105
DE49D786E503C17C5D375AF7EA2
4.38145


106
D97C56B76D0859AE414616627FA
5.5007


107
4BC2612ACD07F5CF1566C0A3183
5.6706


108
4C77A03B55046D1D08178C76ADB
5.62588


109
94E2669F5D6D75DC5AA70272460
5.29578


110
9357E78ED56EE90C46D64EE7F38
5.00808


111
5381C88E308D5D3A6BB609AFBEB
4.48385


112
54B449BFB886C1EA76C7C53A2B3
5.53794


113
8CA1CF3BA0EFDD2925774B3EC09
5.58523


114
8B144E2A28EC41F9380607EB750
5.71655


115
192A799798E3E9986C26512A128
5.01001


116
1E9FB88600E8754A71579DBFA71
5.89436


117
C68A7E020889698B23E713FB4CB
5.25553


118
C1BFBF13908AF1593F96DF2EF92
5.47731


119
4F6CCA14C6E6D1DE253F81EA8C1
5.4871


120
48590B055EE54D0E384E4D3F199
6.18899


121
904C8DA1568451CF6AFEC37BD23
5.35874


122
97794C90CE8FC91D778F8FEE47B
5.46312


123
05C73B0D6E88617E23AFD96F003
5.13605


124
0272BA3CE68BFDAE3EDE95BA95B
5.70272


125
DA673C98EEEAE56F6D6E1BBE5E0
6.26171


126
DD52BD8976E17DBD701F576BCB8
5.50515.

53. A method for providing a pilot symbol for base station identification in a Multiple-Input Multiple-Output (MIMO) communication system having one or more transmit antennas, the method comprising:
generating, by a pilot signal generator, the pilot symbol,
wherein the pilot symbol is comprised of a first sequence having a good cell identification characteristic and a second sequence for reducing a peak-to-average power ratio (PAPR) for all of pilot symbols,
wherein when the number of the transmit antennas is two and an FFT operation point has a value of 128, the first sequence R(r) is determined by





  
    
      R
      ⁡
      
        (
        r
        )
      
    
    =
    
      
        b
        
          IDcell
          +
          1
        
      
      ⁢
      
        g
        
          ∏
          
            (
            r
            )
          
        
      
    
  
  ,
  
    r
    =
    
      
        
          8
          *
          
            ⌊
            
              m
              9
            
            ⌋
          
        
        +
        
          m
          ⁢
          
            
          
          ⁢
          mod
          ⁢
          
            
          
          ⁢
          9
        
      
      =
      0
    
  
  ,
  1
  ,
  ...
  ⁢
  
    
  
  ,
  47
  ,
  and



wherein bk represents a k-th row vector of a block code generator matrix, k represents a value calculated by adding a cell identifier IDcell and 1, gu represents a u-th column vector of the block code generator matrix, and u represents an r-th element of an interleaving pattern according to an interleaving scheme Π(r).

54. The method of claim 53, wherein the first sequence is created by block-coding information to be transmitted from a base station to a mobile station.

55. The method of claim 54, wherein the information to be transmitted from the base station to the mobile station is a cell identifier (ID).

56. The method of claim 53, wherein the second sequence is created from a predetermined reference table taking the first sequence into account.

57. The method of claim 53, wherein the pilot symbol for base station identification is determined by the following equation in which the first sequence and the second sequence are reflected,




  
    
      q
      
        ID
        cell
      
    
    ⁡
    
      [
      m
      ]
    
  
  =
  
    {
    
      
        
          
            
              R
              ⁡
              
                (
                
                  
                    8
                    *
                    
                      ⌊
                      
                        m
                        9
                      
                      ⌋
                    
                  
                  +
                  
                    m
                    ⁢
                    
                      
                    
                    ⁢
                    mod
                    ⁢
                    
                      
                    
                    ⁢
                    9
                  
                
                )
              
            
            ,
          
        
        
          
            
              
                where
                ⁢
                
                  
                
                ⁢
                m
                ⁢
                
                  
                
                ⁢
                mod
                ⁢
                
                  
                
                ⁢
                9
              
              =
              0
            
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            7
          
        
      
      
        
          
            
          
        
        
          
            
              m
              =
              0
            
            ,
            1
            ,
            ...
            ⁢
            
              
            
            ,
            
              
                
                  N
                  used
                
                
                  N
                  t
                
              
              -
              1
            
          
        
      
      
        
          
            
              T
              ⁡
              
                (
                
                  ⌊
                  
                    m
                    9
                  
                  ⌋
                
                )
              
            
            ,
          
        
        
          
            
              where
              ⁢
              
                
              
              ⁢
              m
              ⁢
              
                
              
              ⁢
              mod
              ⁢
              
                
              
              ⁢
              9
            
            =
            8
          
        
      
    
  



where Nused denotes a number of used subcarriers, Nt, indicates a number of the transmit antennas, R(r) denotes the first sequence, and T(−) denotes the second sequence.