Source: https://patents.google.com/patent/KR101368506B1/en
Timestamp: 2020-01-25 23:57:16
Document Index: 143815534

Matched Legal Cases: ['art 2', 'arts 6', 'arts 6', 'arts 6', 'art 31', 'art 31', 'art 31', 'art 31', 'art\n3']

KR101368506B1 - New frame and signalling pattern structure for multi-carrier systems - Google Patents
New frame and signalling pattern structure for multi-carrier systems Download PDF
KR101368506B1
KR101368506B1 KR1020090049231A KR20090049231A KR101368506B1 KR 101368506 B1 KR101368506 B1 KR 101368506B1 KR 1020090049231 A KR1020090049231 A KR 1020090049231A KR 20090049231 A KR20090049231 A KR 20090049231A KR 101368506 B1 KR101368506 B1 KR 101368506B1
KR1020090049231A
KR20090127087A (en
로타르 스태델마이어
사무엘 어생뱅 어텅시리
마틴 로벨
다모쯔 이께다
2008-06-04 Priority to EP08157548.2A priority Critical patent/EP2131540B1/en
2008-06-04 Priority to EP08157548.2 priority
2008-06-04 Priority to EP08157549.0A priority patent/EP2131519B1/en
2008-06-04 Priority to EP08157549.0 priority
2008-06-13 Priority to EP08158289.2A priority patent/EP2131542B1/en
2008-06-13 Priority to EP08158289.2 priority
2008-06-13 Priority to EP08158291.8 priority
2008-06-13 Priority to EP08158291.8A priority patent/EP2134044B1/en
2009-06-03 Application filed by 소니 주식회사 filed Critical 소니 주식회사
2009-12-09 Publication of KR20090127087A publication Critical patent/KR20090127087A/en
2014-03-12 Publication of KR101368506B1 publication Critical patent/KR101368506B1/en
The present invention relates to a transmission apparatus for transmitting signals in a multi-carrier system based on a frame structure, wherein each frame includes at least two signaling patterns and at least two data patterns adjacent to each other in a frequency direction. The transmitting device comprises: signaling mapping means (57) adapted to map signaling data on frequency carriers of each of said at least two signaling patterns having a same length in a frame; Data mapping means (58, 58 ', 58 ") adapted to map data on frequency carriers of said at least two data patterns in a frame; Conversion means (60) adapted to transform the signaling patterns and the data patterns from the frequency domain to the time domain to produce a time domain transmission signal; And transmitting means 61 adapted to transmit the time domain transmission signal. The invention further relates to a corresponding transmission method and a frame pattern for a multicarrier system.
Multi-carrier system, transmitter, receiver, frame pattern, frequency domain, time domain
NEW FRAME AND SIGNALLING PATTERN STRUCTURE FOR MULTI-CARRIER SYSTEMS}
The present invention relates to a new frame and signaling pattern structure for a multicarrier system.
Accordingly, the present invention is primarily intended for broadcasting such as cable-based or terrestrial digital broadcasting systems, for example, after content data, signaling data, pilot signals, etc. are mapped onto a plurality of frequency carriers, and then transmitted with a given total or complete transmission bandwidth. It is about (but not limited to) systems.
Typically, a receiver is tuned to a partial channel (part of the total transmission bandwidth) of the complete transmission bandwidth (sometimes referred to as segment reception) to receive only the content data that each receiver needs or wants. Thus, for example in the ISDB-T standard, the total channel bandwidth is divided into fixed segments of 13 equal lengths (the same number of frequency carriers).
It is therefore an object of the present invention to provide a signal structure for a multi-carrier system as well as a transmission apparatus and method which enables the receiver to be flexibly tuned to any required portion of the overall transmission bandwidth.
This object is achieved by the transmitting device according to claim 1. The transmitting apparatus according to the present invention is adapted to transmit signals in a multicarrier system based on a frame structure, each frame comprising at least two signaling patterns and at least two data patterns adjacent to each other in the frequency direction, The transmitting device
Signaling mapping means adapted to map signaling data on frequency carriers of each of the at least two signaling patterns each having the same length in a frame;
Data mapping means adapted to map data on frequency carriers of the at least two data patterns in a frame;
Conversion means adapted to transform the signaling patterns and the data patterns from the frequency domain to the time domain to produce a time domain transmission signal; And
Transmission means adapted to transmit the time domain transmission signal
The object is further achieved by a transmission method according to claim 9. The transmission method according to the present invention is adapted to transmit signals in a multicarrier system based on a frame structure, each frame comprising at least two signaling patterns and at least two data patterns adjacent to each other in the frequency direction, Way
Mapping signaling data on frequency carriers of each of the at least two signaling patterns each having the same length in a frame;
Mapping data on frequency carriers of said at least two data patterns in a frame;
Converting the signaling patterns and the data patterns from frequency domain to time domain to produce a time domain transmission signal; And
Transmitting the time domain transmission signal
The object is further achieved by a frame pattern according to claim 10. The frame pattern of the present invention is adapted to a multi-carrier system and includes at least two signaling patterns adjacent to each other in the frequency direction, and at least two data patterns, each of the at least two signaling patterns each having the same length in the frame. Signaling data is mapped onto frequency carriers and data is mapped onto frequency carriers of the at least two data patterns in the frame.
It is an object of the present invention to further provide a receiving apparatus and method which enables flexible tuning for any necessary part of the transmission bandwidth, as well as a system and method for transmitting and receiving signals in a multicarrier system.
This object is achieved by a receiving device according to claim 11. The receiving device according to the present invention is adapted to receive signals in a multicarrier system based on a frame structure within a transmission bandwidth, each frame having adjacent signaling data mapped to frequency carriers adjacent to each other in the frequency direction. At least two signaling patterns, and at least two data patterns having data mapped onto frequency carriers, each of the at least two signaling patterns having the same length, wherein the receiving device is one of the signaling patterns Receiving means having at least a length of a signaling pattern of and adapted to receive and tune to a selected portion of said transmission bandwidth covering at least one data pattern to be received; And evaluation means adapted to evaluate the signaling data included in the received signaling pattern to enable reception of the at least two data patterns.
The object is further achieved by a receiving method according to claim 22. The receiving method of the present invention is adapted to receive signals in a multicarrier system based on a frame structure within a transmission bandwidth, each frame being at least adjacent to each other in the frequency direction and each having signaling data mapped onto frequency carriers. Two signaling patterns, and at least two data patterns having data mapped onto frequency carriers, each of the at least two signaling patterns having the same length, and the receiving method comprises one of the signaling patterns Receiving a selected portion of the transmission bandwidth having at least a length of a signaling pattern and covering at least one data pattern to be received; And evaluating signaling data included in the received signaling pattern to enable reception of the at least two data patterns.
The object is further achieved by a system for transmitting and receiving signals according to claim 23, wherein the system comprises a transmitting device for transmitting signals in a multicarrier system based on a frame structure, each frame having a frequency At least two signaling patterns adjacent to each other in a direction, and at least two data patterns;
The system further comprises a receiving device according to the invention adapted to receive the time domain transmission signal from the transmitting device.
The object is further achieved by a method for transmitting and receiving signals according to claim 24, the method comprising a transmission method for transmitting signals in a multicarrier system based on a frame structure, wherein each frame is frequency At least two signaling patterns adjacent to each other in a direction, and at least two data patterns;
The method further comprises a receiving method according to the invention, which is adapted to receive the time domain transmission signal.
Accordingly, the present invention proposes a multicarrier system using a frame structure or a frame pattern in the frequency domain as well as the time domain. In the frequency domain, each frame includes at least two signaling patterns, each of which carries signaling data or information on frequency carriers, each having the same length (or bandwidth). After conversion to the time domain, in the resulting time domain signal, each frame contains each signaling symbol as well as a data symbol. Each frame pattern covers a complete or total transmission bandwidth in the frequency direction, so that the overall transmission bandwidth is equally divided into signaling patterns having the same respective length. The data patterns of each frame then follow the signaling patterns in time. If any desired portion of the transmission bandwidth that the receiving device can tune to has at least the length of one of the signaling patterns, the receiving device can be freely and flexibly tuned to any desired portion of the transmission bandwidth. . Accordingly, the receiving device can always receive the signaling data of the complete signaling pattern, and thus data patterns can be received at the receiving device based on and using the signaling data including the physical layer information necessary for receiving subsequent data patterns. have.
Advantageously, each frame comprises at least two additional signaling patterns that follow the at least two signaling patterns in a time dimension, each of the additional signaling patterns being associated with a corresponding signaling pattern of the at least two preceding signaling patterns, respectively. Have the same length. Accordingly, even if the length (or bandwidth) of each signaling pattern is not long enough to contain all the necessary signaling data, the remaining signaling data required in the additional signaling data can be transmitted. Thus, even if the receiving device has a rather small (effective) reception bandwidth, it is possible to transmit and receive all necessary signaling data.
More advantageously, each frame includes at least two training patterns, with pilot signals mapped on the frequency carriers of each training pattern in the frame, and the signaling patterns aligned with the training patterns in the frequency direction. Accordingly, through the training patterns preceding the signaling patterns in the time direction, the receiving device that first receives the training pattern may perform time synchronization, frequency offset calculation and / or channel estimation, and then the received signaling patterns Signaling data within can be received and can be used to receive subsequent data patterns, regardless of the tuning position of the receiving device. For example, all training patterns have the same length, and the odds of each signaling pattern are equal to the length of each of the training patterns. Alternatively, all training patterns have the same length, and the length of each signaling pattern is less than the length of each of the training patterns. Accordingly, the length of each signaling pattern may be half the length of each of the training patterns. Implementations in which the signaling patterns are not aligned with the training patterns may be possible.
Advantageously, each signaling pattern includes at least one guard band. Accordingly, it is guaranteed that the receiving device can receive all signaling data in the signaling pattern even when the effective receiving bandwidth is smaller than the tuning bandwidth due to, for example, filter characteristics. Accordingly, each signaling pattern may include a guard band at its beginning and a guard band at its end.
Advantageously, each signaling pattern of each frame includes the location of the signaling pattern within the frame, which is extracted and evaluated at the receiving end. In this case, more advantageously, each signaling pattern in each frame may include the same signaling data except for the location of each signaling pattern in the frame that is different in at least some of the signaling patterns in the frame. Accordingly, the receiving device determines its position within the total transmission bandwidth (in each frame), for example, during an initialization period in which he is tuned to any position in the frame, and then, based on the signaling data in the received signaling pattern, It may be tuned to a bandwidth that enables reception.
More advantageously, the signaling patterns of each frame include signaling data indicating the number of data patterns included in the frame. More advantageously, the structure of the signaling data in the signaling patterns supports a limited maximum number of data patterns in the frequency direction of each frame. In addition, the signaling patterns of each frame may include separate signaling data for each data pattern included in the frame.
More advantageously, the signaling data in the signaling patterns include error detection and / or correction coding. Accordingly, even when the receiving device cannot receive the complete signaling pattern, the receiving device can still obtain the complete signaling information included in the signaling pattern.
The receiver can be flexibly tuned to any desired portion of the transmission bandwidth, but due to the new frame structure proposed by the present invention, it is always possible to receive signaling data in a complete signaling pattern. Advantageously, the receiving apparatus comprises reconstruction means adapted to reconstruct the original signaling pattern from the selected portion of the received transmission bandwidth. Accordingly, the reconstruction means can be adapted to rearrange the received signaling signals into the original signaling pattern when the selected portion of the transmission bandwidth on which the receiving means is tuned does not match the signaling pattern structure. Thus, even if the selected portion of the transmission bandwidth to which the receiver is tuned does not match completely and exactly with one of the signaling patterns (in the frequency direction), in that case the receiver is the last part of the preceding signaling pattern (in the frequency direction) and ( Will receive the first part of the subsequent signaling pattern) (in the frequency direction). For example, if the receiving device knows its (frequency dimension) offset from the signaling pattern structure in each frame, the reconstruction means can be adapted to rearrange the received signaling signals into the original signaling pattern. Alternatively, each frame includes at least two additional signaling patterns that follow at least two signaling patterns in the time dimension, each of the additional signaling patterns having a length equal to each of the corresponding signaling patterns of the at least two preceding signaling patterns, respectively. And the reconstruction means is adapted to rearrange the received two or more signaling patterns that follow each other in the time dimension to the original signaling pattern. Accordingly, the preceding signaling pattern and the subsequent signaling pattern may include necessary signaling data together even when the length of the signaling patterns in the frequency dimension is short, when all necessary signaling data are included in a single signaling pattern.
Alternatively or in addition, the signaling data of the signaling patterns include error detection and / or correction coding, wherein the reconstruction means is adapted to perform error detection and / or correction decoding on the received signaling signals to reconstruct the original signaling pattern. Is adapted. Accordingly, the transmitted signaling patterns may include additional error coding, redundancy, and the like that allow the receiver to reconstruct the original signaling pattern even if only a portion of the signaling pattern can be received. Advantageously, each signaling pattern of each frame includes the location of the signaling pattern within the frame, which is extracted and evaluated at the receiving end. In this case, more advantageously, each signaling pattern in each frame may include the same signaling data, except for the location of each signaling pattern in the frame that is different in at least some of the signaling patterns in the frame. Accordingly, the receiving device determines its position within the total transmission bandwidth (in each frame), for example, during an initialization period in which he is tuned to any position in the frame, and then, based on the signaling data in the received signaling pattern, It may be tuned to a bandwidth that enables reception. Advantageously, the signaling patterns of each frame comprise signaling data having the number of data patterns included in the frame, and the evaluation means is adapted to extract the signaling data having the number of data patterns from the received signaling pattern. More advantageously, the signaling patterns of each frame comprise individual signaling data having respective data patterns contained in the frame, and the evaluation means is adapted to extract the individual signaling data having each data pattern from the received signaling pattern. .
Advantageously, the receiver is tuned to and receives a selection of the transmission bandwidth, thus enabling optimal reception of the signaling pattern in the selection of the transmission bandwidth. In particular, if the frequency dimension structure of the data patterns and signaling patterns in the frame does not match, and the selection portion of the transmission bandwidth to be received at the receiver is larger (in frequency dimension) than the data pattern (s) to be received, for example It may be possible to optimize the tuning so that the best possible reception of the signaling pattern is achieved by adjusting the tuning so that a maximum portion of one complete signaling pattern is received while still receiving the desired complete data pattern (s).
In general, it may be beneficial to tune the receiver to receive the selected portion of the transmission bandwidth such that at least one data pattern to be received is centered with respect to the selected portion of the transmission bandwidth.
More advantageously, the receiver may be tuned to receive the selected portion of the transmission bandwidth based on the signaling information received in the signaling pattern of the previous frame.
More advantageously, each frame includes additional data patterns that follow at least two data patterns in the time dimension, each of the additional data patterns having a length equal to each of the corresponding data patterns of the preceding at least two data patterns, respectively. . That is, the structure of the data patterns in each frame is advantageously set up in such a way that at least two data patterns are arranged next to each other in the frequency dimension so that the entire bandwidth is covered. Subsequently, additional data patterns are arranged in the same frame but subsequent to at least two data patterns in the time direction, each additional or subsequent data pattern having the same length (in frequency dimension or direction) as the preceding data pattern at the same frequency position. Have Thus, when the receiving device is tuned to a particular portion of the transmission bandwidth, at least two data patterns are received per frame, each of which has the same length but follows each other in the time dimension. Accordingly, the length of each of the data patterns in the transmitting device can be dynamically adjusted. Alternatively or in addition, the number of additional data patterns in the time dimension may be dynamically adjusted. Subsequently, any dynamic changes regarding the data patterns will be signaled in the signaling patterns. Thus, a multicarrier system having a frame structure as proposed by the present invention may allow the length of the data patterns, and thus the amount of data per data pattern, to be dynamically changed, for example, per frame or in any other necessary manner. It enables the transmission of highly flexible data content. Alternatively, the length and / or number of data patterns can be fixed or invariant.
It is to be understood that the present invention can be applied to any kind of multicarrier system in which the transmitting device is adapted to transmit data in the entire transmission bandwidth and the receiving device is adapted to selectively receive only a portion of the total transmission bandwidth. Non-limiting examples of such systems may be existing or future one-way or two-way broadcast systems such as wired or wireless (eg, cable based, terrestrial, etc.) digital video broadcast systems. A non-limiting example for a multicarrier system is an Orthogonal Frequency Division Multiplex (OFDM) system, but any other suitable system for mapping signaling data, pilot signals, and other kinds of data on a plurality of frequency carriers may be used. . Accordingly, the frequency carriers are equidistant and may each have the same length (bandwidth). However, the present invention may be used in multicarrier systems where the frequency carriers are not equidistant and / or do not each have the same length. In addition, it should be understood that the present invention is not limited to any kind of specific frequency range even in the entire transmission bandwidth applied to the transmission side, and in the selection portion of the transmission bandwidth to which the reception side is tuned. However, in some applications, it may be advantageous to use the bandwidth for the portion of the transmission bandwidth that the receiver can tune to, corresponding to the reception bandwidth on the receiving side, i.e. the bandwidth of the receiving devices of existing (digital video broadcasting or other) systems. have. A non-limiting example of receiver bandwidth may be 8 MHz, ie the receiving side may be tuned to any desired 8 MHz bandwidth from the full transmission bandwidth. Accordingly, the overall transmission bandwidth may be a multiple of 8 MHz, for example 8 MHz 16 MHz, 24 MHz, 32 MHz, etc., so that the division of the overall transmission bandwidth, i.e. the length of each training pattern, may be 8 MHz. However, other divisions, eg the length of each training pattern of 6 MHz, are possible (but not limited to). In general, in the case of a non-limiting example of 8 MHz with respect to the receiver bandwidth, the length of each of the signaling patterns used in the frame structure of the present invention may be 8 MHz, 4 MHz (or less).
The invention is explained in more detail in the description of the preferred embodiments below in connection with the included figures.
According to the invention, it is possible for the receiver to be flexibly tuned to any necessary part of the overall transmission bandwidth.
1 shows a schematic representation of the total transmission bandwidth 1 in which a transmitting device according to the invention, for example the transmitting device 54 schematically shown in FIG. 17, transmits signals in a multicarrier system according to the invention. Indicates. 1 also schematically shows a block diagram of a receiving device 3 of the invention, which is tuned to a selected part 2 of the transmission bandwidth 1 and adapted to selectively receive it. Accordingly, the receiving device 3 is tuned to the desired portion 2 of the transmission bandwidth 1 and adapted to the respective communication system, such as demodulation, channel decoding, etc., as well as the tuner 4 adapted to selectively receive it. Further processing means 5 for performing further necessary processing of the received signals accordingly. A more elaborate example of a receiving device according to the invention is shown in the schematic block diagram of FIG. 18, which is for example antenna, antenna pattern, wired or cable based adapted to receive signals in each transmission system or communication system. Illustrates a receiving device 63 comprising a receiving interface 64 which may be a receiving interface or any other suitable interface. The receiving interface 64 of the receiving device 63 is not only a tuning means such as the tuning means 4 shown in FIG. 1, but also a down conversion means adapted to down convert the received signal to an intermediate frequency or baseband, It is connected to a receiving means 65 comprising additional essential processing elements according to each transmission or communication system.
As mentioned above, the present invention provides a unique and novel frame structure for a multi-carrier system, thereby enabling flexible and variable reception of the desired portion 2 of the transmission bandwidth 1 at the receiver. 2 adapts the transmitting device 54 of the present invention to transmit data content such as video data, audio data or any other kind of data in different segments or parts 6, 7, 8, 9, 10 A schematic representation of the total transmission bandwidth 1 is shown. For example, portions 6, 7, 8, 9, 10 may be used by transmitting device 54 to transmit different kinds of data, data from different sources, data designated for different receivers, and the like. have. The parts 6, 9 have, for example, a maximum bandwidth, ie the maximum bandwidth that can be received by the corresponding receiving device 63. The portions 7, 8, 10 have smaller bandwidths. The present invention now proposes to apply a frame structure or pattern to the overall transmission bandwidth, whereby each frame comprises at least two training patterns and a plurality of data patterns that are adjacent to each other in the frequency direction. Each training pattern of a frame will have the same length and the same pilot signals. That is, the overall transmission bandwidth 1 is divided into equal parts for the training patterns, so that the maximum bandwidth that the receiver can tune to, for example the bandwidth shown for the parts 6, 9 of FIG. It must be equal to or greater than the length of each training pattern. Accordingly, by appropriately receiving the entire training pattern, the receiving device 63 according to the present invention can be accurately synchronized with the transmitting device 54 and tuned to the desired data in a flexible and non-limiting manner to receive the data. In addition, the reception device 63 may perform frequency offset calculation and / or channel estimation based on the received training pattern. In addition, it is clear that the length of the various data portions in the transmission bandwidth cannot exceed the length of the training patterns (number of frequency carriers) in each frame as described below.
3 shows a schematic representation of the time domain structure of the frames 11, 11 ′, 11 ″ according to the invention. Each frame 11, 11 ', 11' 'is a preamble symbol (or training symbol) 12, 12', 12 '', one or more signaling symbols 13, 13 'and several data symbols 14, 14 Include '). Thus, in the time domain, preamble symbols or training symbols precede signaling symbols preceding data symbols. Each frame 11, 11 ′, 11 ″ may have a plurality of data symbols, and systems are possible in which the number of data symbols in each frame 11, 11 ′, 11 ″ varies. The preamble symbols are used at the receiving device 63 to eventually perform additional tasks such as time synchronization and channel estimation and / or frequency offset calculation. The signaling symbols 13, 13 ′ contain signaling information, for example all physical layer information necessary for the receiving device 63 to decode received signals, such as but not limited to L1 signaling data. The signaling data may include, for example, the allocation of data content for various data patterns, i.e., data on which frequency carriers are located, for example, which services, data streams, modulation, error correction settings, etc. The receiving device 63 can thus obtain information as to which part of the overall transmission bandwidth he is to tune. In addition, the signaling symbols may include signaling data indicating an offset of the preamble or training pattern and / or each data pattern from the signaling pattern, such that the receiving device 63 receives the training patterns and / or signaling patterns. In this optimized manner, tuning for the desired portion of the transmission frequency can be optimized. The use of a frame structure in accordance with the present invention allows, by dividing the data stream into logical blocks, changes in the frame structure are signaled from frame to frame so that the preceding frame will signal subsequent frames or the modified frame structure of one of them. Has an additional benefit. For example, the frame structure allows for flawless change of modulation parameters without generating an error.
4 (a), 4 (b), 5 (a) and 5 (b) show non-limiting examples of preamble structures that can be used in the present invention. However, it should be understood that other possible preamble structures may also be used. 4A shows a frequency domain representation of a preamble or training pattern 15 in which a plurality of frequency carriers 16 (2048 carriers in the illustrated example) each hold pilot signals. That is, all frequency carriers of the training pattern 15 carry pilot signals. FIG. 4B shows the training pattern of FIG. 4A after conversion to the time domain. The time domain training symbol includes a plurality of time domain samples 17 (2048 samples in the example shown) in a single iteration. That is, the time domain training symbol has no repetitions of time domain samples. 5A shows an additional non-limiting example of a frequency domain preamble pattern 18 comprising a plurality of frequency carriers (512 carriers in the illustrated example). In the example shown, only every fourth subcarrier carries a pilot signal 19 and all other subcarriers 20 do not carry a pilot signal. After conversion to the time domain, the time domain preamble or training symbol 21 shown in FIG. 5 (b) represents four iterations 22, with each iteration 22 representing the same samples 23 (the same). Value and number). In the example shown, the time domain training symbol has a length of 2048 time samples, and each iteration 22 includes 512 samples. The general rule is that the number of repetitions in the time domain corresponds to the repetition rate of pilot signals in the frequency domain. If the distance of pilot signals in the frequency domain is larger, the number of repetitions in the time domain is increased. Repetitions within a time domain preamble or training symbol are sometimes referred to as 'shortened' training symbols. Thus, in the example of FIG. 5B, the time domain symbol includes four shortened training symbols. In some applications, it may be beneficial to use pseudo noise pilot signal sequences to obtain pseudo noise, such as signal patterns in the time domain. In addition, any other suitable sequence that results in a so-called constant amplitude zero auto correlation (CAZAC) sequence, or pseudo noise, such as signal patterns, and has good correlation characteristics in both the frequency domain as well as the time domain, may be used for the pilot signals. Can be used. Such sequences enable time synchronization at the receiving device 63 of the present invention. In addition, such sequences enable reliable channel estimation at the receiving device 63 when the Nyquist criterion is implemented in the frequency dimension. In addition, such sequences enable frequency offset calculation and / or channel estimation at the receiving device 63.
As described above, the present invention proposes a frequency domain frame structure or frame pattern for the entire transmission bandwidth of the transmitting device 54, in which the same training patterns are repeated over the entire transmission bandwidth, i.e. Immediately adjacent. 6 schematically shows a sequence of such and adjacent such training patterns 25, 26, 27, 28 in the overall transmission bandwidth 24. That is, the same sequence of pilot signals is mapped onto the frequency carriers of each training pattern 25, 26, 27, 28 so that each training pattern has the same length (or bandwidth) and the same number of frequency carriers. (It is assumed that frequency subcarriers are equidistant and each have the same length or bandwidth). Advantageously, as shown in FIG. 6, the overall transmission bandwidth 24 is equally divided into training patterns 25, 26, 27, 28 each having the same length. In addition, in order to ensure that the receiving device 63 can always receive the entire training pattern for synchronization (and channel estimation and / or frequency offset calculation), the length of the training patterns 25, 26, 27, 28. Corresponds to a minimum tuning bandwidth in which the receiving device 63 of the present invention can be tuned to receive signals.
Accordingly, the present invention allows the receiving device 63 to perform reliable synchronization, for example by correlating the received pilot signals in the correlation means 67 of the receiving device 63 shown in FIG. Allows tuning to any location within 24 in a very flexible manner. In addition, the present invention proposes to divide the entire transmission frequency bandwidth 24 into adjacent sub-blocks or segments each comprising a repetition of the same pilot signal sequence, and thus each having a training pattern having the same length. Thus, the length of each training pattern advantageously corresponds to the bandwidth over which the receiving device 63 can be tuned. For example, as shown in FIG. 18, the receiving device 63 includes a receiving interface 64 such as an antenna, a wired receiving interface, etc., in which signals are received at the receiving means 65 including a tuner. When the receiving device 63 is tuned to a portion of the transmission bandwidth that matches or matches one of the training patterns, the pilot signal sequences are received in their original order. When the receiving device 63 is tuned to any part of the transmission bandwidth or between two training patterns, for example, all the pilot signals of the training pattern are still received, but not in the original sequence. However, due to the cyclic behavior of the pilot signal sequences, very good correlation properties still exist, especially when pseudo noise sequences are used for the pilot signals in each training pattern, and the correlation of the receiving device 63 of the present invention. The means 67 still deliver good results when performing autocorrelation, ie their own correlation with the received pilot signals. In particular, in wired systems such as cable systems, autocorrelation is expected to deliver good results due to the high signal-to-noise ratio. Such sequences also enable frequency offset calculation and / or channel estimation at the receiving device 63.
7 shows an example of a simulation result of a 64 sample pseudo noise sequence for a multicarrier system without splitting a training pattern. The correlation peak is clearly visible. 8 shows a further example of the simulation results for a system according to the invention in which the entire transmission bandwidth contains training patterns with the same, and the receiver is tuned to a portion of the transmission bandwidth. In the simulation shown in FIG. 8, the receiver was tuned to and equally matched to the first training pattern of the first segment, i.e., the entire transmission bandwidth. That is, the simulation shows the autocorrelation result for the situation where the receiver receives the pilot signals of the training pattern in the original sequence. In addition, the correlation peak is clearly visible. 9 now receives the last portion of the preceding training pattern before the first portion of the continuous training pattern, although the receiver has been tuned to a position between the two training patterns, so that the receiver did not receive the pilot signals in the original sequence. The simulation results for the system of FIG. 8 are shown. However, due to the cyclic behavior of pilot sequences and training patterns, it is also possible to obtain the autocorrelation peak shown in FIG. 9.
When the receiving device 63 knows its tuning position, i.e., knows the offset from the start of the frame or from each start of each training pattern, the optional rearrangement means 66 can receive the received pilot signals. Cross-correlation results can be obtained by rearranging to the original sequence and performing cross correlation based on a comparison with the stored version of the expected training pattern. Such cross-correlation results are less affected by noise and will typically have better quality than autocorrelation results. Thus, cross correlation may be a better choice for systems with low signal to noise ratio.
10 shows a schematic example of a frequency domain representation of a frame structure or pattern 29 according to the invention. The frame structure 29 covers the entire transmission bandwidth 24 in the frequency direction and includes at least two training patterns 30 adjacent to each other in the frequency direction, each training pattern on each frequency carrier. They hold the same pilot signal sequence and have the same length. In the example shown in FIG. 4, the overall transmission bandwidth 24 is subdivided into four training patterns 30, although any other more or fewer training patterns may be suitable. In the transmission apparatus 54 of the present invention as shown in FIG. 17, the pilot mapping means 55 is adapted to map pilot signals on frequency carriers of each training pattern. Advantageously, a pseudo noise sequence or a CAZAC sequence is used for the pilot signals, but any other sequence with good pseudo noise and / or correlation characteristics may be suitable. In addition, the pilot mapping means 55 may be adapted to map the pilot signal on all frequency carriers in the training patterns as described in connection with FIG. 4. Alternatively, the pilot mapping means 55 may be adapted to map the pilot signal on every m-th frequency carrier, for example as described in connection with FIG. 5 (m is a natural number greater than one). The length or bandwidth 39 of all the training patterns 30 is equal to the bandwidth 38 to which the tuner of the receiving device 63 can be tuned. However, a portion of the transmission bandwidth to which the tuner of the receiving device 63 can be tuned may be greater than the length of the training pattern 30. In addition to the correlation performed in the correlation means 67 in the receiving device 63, the received pilots also provide channel estimation information necessary to enable correct de-mapping of the data in the received data signals. The channel estimation means 69 providing the demapping means 70 may further be used for channel estimation for the carrier frequencies in the frame (after conversion to the frequency domain in the conversion means 68). Also, the received pilots may be used for the frequency offset calculation in the corresponding means not shown in FIG. 18 at the receiving device 63.
The frame structure or pattern 29 further includes at least two signaling patterns 31 adjacent to each other in the frequency direction, along the training patterns 30 in the time domain. Each signaling pattern 31 has the same length and bandwidth as each preceding training pattern 30, and the start and end of each signaling pattern 31 in the frequency direction is the respective (time direction) preceding training pattern ( 30 is the same as the beginning and the end, and therefore the frequency structure of the signaling pattern 31 is the same as the frequency structure of the training pattern 30. That is, the signaling patterns 31 are aligned to the training patterns 30. The transmitting apparatus 54 of the present invention shown in FIG. 17 includes signaling data mapping means 57 which is adapted to map signaling data on frequency carriers of each signaling pattern 31. Accordingly, each signaling pattern 31 includes the position of the signaling pattern 31 in the frame, for example. For example, each signaling pattern 31 in each frame has and holds the same signaling data except for the location of each signaling pattern in the frame that is different in each signaling pattern 31 in the frame. The signaling data is, for example, L1 signaling data including all physical layer information necessary for the receiving device 63 to decode the received signals. However, any other suitable signaling data may be included in the signaling patterns 31. The signaling patterns 31 may comprise the location of each data segment 32, 33, 34, 35, 36, for example, so that the receiving device 63 knows where the desired data segments are located and thus The tuner of the receiving device 63 can be tuned to each position to receive the desired data segments. As shown in Fig. 18, the receiving device 63 includes, after receiving means 65 with a tuner, converting means 68 for converting the received time domain signals into the frequency domain, after which the signaling data It is demapped in the demapping means 72 (after an optional reconstruction in the reconstruction means 71) and then evaluated in the evaluation means 73. The evaluation means 73 is adapted to extract the required signaling information required from the received signaling data. If necessary, additional signaling patterns may be provided in the time direction immediately following the signaling patterns 31.
The frame structure or pattern 29 further includes at least two data segments extending beyond the entire transmission bandwidth 24 in the frequency direction and following the signaling patterns 31 in the time direction. In the time slot immediately following the time slot in which the signaling patterns 31 are located, the frame structure 29 has several data segments 32, 33, 34 having different lengths, ie different numbers of respective frequency carriers that are data mapped. , 35, 36, 37). The frame structure 29 further includes additional data segments in consecutive time slots, such that the additional data patterns each have the same length and number of frequency carriers as the preceding data pattern. For example, the data patterns 32 ′, 32 ″, 32 ′ ″ have the same length as the first data pattern 32. The data patterns 33 ′, 33 ″, 33 ′ ″ have the same length as the data segment 33. That is, the additional data patterns have the same frequency dimension structure as the various data patterns 32, 33, 34, 35, 36, 37 in the first time slot after the signaling patterns 31. Thus, when the receiving device 63 is tuned to a portion 38 of the transmission bandwidth to receive the data / pattern 35, for example, continuous data in all time directions having the same length as the data pattern 35. The patterns 35 ', 35' ', 35' '' can be properly received.
The flexible and variable data pattern structure of the frame structure or pattern 29 as proposed by the present invention is for example different, for example as shown by branch data 1, data 2 and data 3 of FIG. It can be implemented in the transmitting apparatus 54 of the present invention as shown in FIG. 17 by mapping of various different data streams having kinds of data and / or data from different sources. Each data is then mapped onto frequency carriers in each data pattern by respective data mapping means 58, 58 ′, 58 ″. As mentioned above, at least some of the various data patterns may have different lengths, that is, different numbers of frequency carriers, provided that the frequency carriers are each equidistant and have the same bandwidth. Alternatively, the number of data patterns in the frequency direction may be equal to the number of training patterns, and the length (or bandwidth) of each data pattern may be equal to the length of each training pattern, and they may be aligned with each other. (Can have the same frequency direction structure). Alternatively, each data pattern can have the same length, and the number of data patterns can be a multiple of the number of training patterns while still having the same frequency structure and alignment. Thus, for example, two, three, four or more data patterns will be aligned to each of the training patterns. In general, the length of the data patterns need to be less than or equal to the effective receiver bandwidth so that the data patterns can be received at the receiving device 63. In addition, the transmitting apparatus 54 may be adapted to dynamically change the data pattern structure, eg, the length and / or number of data patterns. Alternatively, the structure of the data patterns can be fixed or immutable.
It should also be noted that the data patterns may advantageously include pilot signals mapped on some of the frequency carriers to enable accurate channel estimation at the receiving side. Accordingly, pilot signals may be distributed among carriers with data in a regular or irregular pattern.
Subsequently, in the transmitting apparatus 54, frequency carriers having pilots from the pilot mapping means 55, frequency carriers having signaling data from the signaling mapping means 57, and various data mapping means 58, 58 ', Frequency carriers with data from 58 &quot;) are combined in a frame forming means 59 into a frame pattern or structure 29 according to the invention.
In general, the frame structure of the present invention may be fixed or invariant, ie the total bandwidth of each frame in the time direction, as well as the length, is fixed and may always be the same. Alternatively, the frame structure may be flexible, ie the overall bandwidth and / or length of each frame in the time direction may be flexible and change from time to time depending on the desired application. For example, the number of time slots with data patterns can be flexibly changed. Accordingly, changes can be signaled to the receiving device within the signaling data of the signaling patterns.
As can be seen in FIG. 10, the portion 38 in which the receiving device 63 is tuned does not match the frequency structure of the training patterns 30 and the signaling patterns 31. However, as described above, due to the cyclicity of the pilot signal sequences in the training patterns 30, the correlation means 67 of the receiving device 63 can still perform auto (or cross) correlation. In addition, in the situation shown in FIG. 10, in order for the reception apparatus 63 to rearrange the received signaling carriers into the original signaling sequence of the signaling patterns 31 (which is performed by the reconstruction means 71), Knowledge of the offset of the portion 38 associated with the frequency structure of the frame pattern 29 is required. This is due to the fact that the signaling patterns 31 have the same length and frequency structure as the training patterns 30.
During the startup or initialization phase of the receiving device 63, the receiving device 63 is tuned to any frequency portion of the entire frequency bandwidth. In a non-limiting example of a cable broadcast system, training pattern 30 may have an 8 MHz bandwidth, for example. Thus, during the startup phase, the receiving device 63 selects the entire training pattern 30 in the original or rearranged sequence as well as the entire signaling pattern 31 in the original or rearranged sequence from the received training pattern 30. Can be received. The receiving device 63 performs correlation in the correlation means 67 to obtain time synchronization, as well as performs channel estimation (generally, approximate channel estimation) in the channel estimation means 69, and / or transforms. The frequency offset calculation may be performed after converting the time domain signals received at the means 68 into the frequency domain. In the evaluation means 73 of the receiving device 63, the received signaling data is evaluated, for example, the position of the received signaling pattern in the frame is obtained, so that each of the receivers is the same as the portion 38 shown in FIG. It can be freely and flexibly tuned to the desired position. Typically in a new tuning position that does not need to match the frequency structure of the training patterns 30 and signaling patterns 31, the receiving device 63 is still due to the cyclicity of the pilot signals of the training patterns 30. To perform synchronization, channel estimation and frequency offset calculation based on them. However, in order to be able to properly evaluate the signaling data of the signaling patterns 31, the received signaling signals must be rearranged, which is performed in the reconstruction means 71 as described above. 11 shows a schematic example of such rearrangement. The last part 31 ′ of the previous signaling pattern is received before the first part 31 ″ of the subsequent signaling pattern, and then the reconstruction means 71 places the part 31 ′ behind the part 31 ″, The original sequence of signaling data is reconstructed, and the rearranged signaling pattern is then evaluated in the evaluation means 73 after the corresponding demapping of the signaling data from the frequency carriers in the demapping means 72. It should be remembered that the content of each signaling pattern is the same, so this rearrangement is possible.
Often, the receiving device does not provide a flat frequency response over the complete receive bandwidth to which the receiver is tuned. In addition, the transmission system generally faces increased attenuation at the boundary of the receive bandwidth window. 12 shows a schematic representation of a typical filter shape example. The filter is not rectangular, so it can be seen that the receiving device can effectively receive only the 7.4 MHz bandwidth, for example instead of the 8 MHz bandwidth. As a result, the receiving device 63 does not rearrange the signaling data as described with respect to FIG. 11 when the signaling patterns 31 have the same length and bandwidth as the receiving bandwidth of the receiving device 63. May be lost, and thus some signals are lost and not received at the boundary of the reception bandwidth. In order to overcome these and other problems, and to ensure that the receiving device 63 can always receive complete signaling patterns in the original sequence, there is no need to rearrange or rearrange the received signaling signals. Alternatively or additionally suggests the use of signaling patterns 31a with a reduced length compared to training patterns 30. In the example shown in FIG. 13, the use of signaling patterns 31a having exactly half the length of the training pattern 30, but still having the same frequency structure as the training patterns 30, is proposed. That is, as shown in FIG. 13, two (ie pairs) of each of the half-length signaling patterns 31a are matched and aligned with each one of the training patterns 30. Accordingly, each pair of signaling patterns 31a will have the same signaling data that includes the location of the signaling patterns 31a in each frame. However, with respect to other pairs of signaling patterns, in these other pairs, since they have each different location in the frame, the signaling data will be the same except for the location information. In the above example of each training pattern 30 having a bandwidth or length of 8 MHz, the signaling pattern 31a will each have a length or bandwidth of 4 MHz. Accordingly, to ensure that the same amount of signaling data can be transmitted as before, an additional half length in front of the data patterns 32, 34, 35, 36, 37 in the time slot following the signaling patterns 31a. It may be necessary to add signaling patterns 31b. The additional signaling patterns 31b have the same time and frequency arrangement / alignment as the signaling patterns 31a, but are in addition to the signaling information contained in the signaling patterns 31a and include other signaling information. In this way, the receiving device 63 can fully receive the signaling patterns 31a and 31b, and the reconstruction means 71 of the receiving device combines the signaling data of the signaling patterns 31a and 31b into the original sequence. Is adapted to. In this case, the reconstruction means 71 in the receiving device 63 can be omitted. In addition, if all the necessary signaling data can be transmitted in half length, and additional signaling patterns 31b are not needed, it is possible to provide only one time slot with half length signaling patterns 31a. . Alternatively, even more half-length signaling patterns can be used in successive time slots behind signaling patterns 31b. In general, as described above, the length (or bandwidth) of the training patterns, data patterns and / or signaling patterns is determined by the effective reception bandwidth of the receiving device 63, for example. It should be noted that it may be adapted to the output bandwidth of the receive bandpass filter, for example it may be smaller or as large as possible.
Further, in general, the training patterns, signaling patterns and / or data patterns of the frame structure described by the present invention may include additional guard bands, i.e., unused carriers, at the beginning and / or end of each pattern or frame. Note that there is. For example, each training pattern may include a guard band at the beginning and end of each pattern. Alternatively, in some applications, only the first training pattern in each frame, in the example of FIG. 10, only the training pattern at position 39 includes the guard band at the beginning of the pattern, and the last training pattern in each frame only at the end of the pattern. It may be beneficial to include a guard band. Alternatively, in some applications, only the first training pattern in each frame, in the example of FIG. 10, only the training pattern at position 39 includes a guard band at the beginning as well as the end of the pattern, and the last training pattern in each frame is It may be advantageous to include a guard band at the beginning as well as at the end of the pattern. The length of the guard band included in some or all of the training patterns may be, for example, less than or equal to the maximum frequency offset that the receiving device can cope with. In the above example of the bandwidth of 8 MHz for each training pattern, the guard band may have a length of, for example, 250 to 500 kHz or any other suitable length. Further, the length of each of the guard bands included in the training patterns may be at least the length of carriers that are not received at the receiving device due to the filter characteristic as described with reference to FIG. 12. In addition, when the signaling patterns have guard bands, the length of each of the guard bands included in the training patterns may be at least the length of each of the signaling pattern guard bands.
Additionally or alternatively, each signaling pattern, ie signaling patterns 30, 31a and / or 31b, may include a guard band with unused carriers at the beginning and end of each pattern. An example of such a situation is shown in FIG. 15, which shows that several signaling patterns 31a each have a guard band 31a 'at the beginning and an additional guard band 31a' 'at the end of the frequency dimension. It is schematically shown that the arrangement in succession with each other. For example, the total transmission bandwidth is a multiple of the training pattern length of 8 MHz (4nk mode: k is the Fourier window size of 1024 carriers / samples, n = 1, 2, 3, 4, ...), respectively. In an OFDM system with a signaling pattern of 4 MHz in length, the proposal for the length of each guard band at the beginning and end of each signaling pattern yields 343 frequency carriers (that is, the beginning and end of each frame in each 4nk mode). Number of carriers not used in the end data patterns). The resulting number of carriers available in each signaling pattern will be 3584/2-2x343 = 1106 carriers. However, these numbers are only used as examples and are not intended to be limiting in any sense. Accordingly, the length of each of the guard bands included in the signaling patterns may be at least the length of carriers that are not received at the receiving device due to the filter characteristic as described with respect to FIG. 12, and thus within each signaling pattern. The length of the signaling data is equal to (or may be less than) the effective receiver bandwidth. As described in connection with FIG. 13, it should be noted that if additional signaling patterns 31b are present, they will have the same guard bands 31a ', 31a' 'as the signaling patterns 31a. . In addition, as described with reference to FIG. 13, the signaling patterns 30 may have guard bands 31a ′, 31a ″ as described.
Additionally or alternatively, each data pattern may include a guard band with unused carriers at the beginning and end of each pattern. Alternatively, in some applications, each first data pattern in each frame in the frequency direction, only the data patterns 32, 32 ', 32' ', 32' '' in the example of FIGS. 10 and 13 It may include a guard band only at the beginning of the final data patterns in each frame in the frequency direction, the data patterns 37, 37 ', 37' ', 37' '' in the example of FIGS. The guard band may be included at the end of the data pattern. Thus, the length of the guard bands in the data patterns may be the same as the length of the guard bands of the signaling patterns, for example, if the signaling patterns include guard bands, and / or the training patterns include the guard bands. In this case it may be equal to the length of the guard bands of the training patterns.
As described above, the signaling data included in the signaling patterns 31, 31a and / or 31b (or other signaling patterns according to the present invention) may be transmitted by the receiving device 63 according to the present invention. And physical layer information that makes it possible to obtain and receive and decode desired data patterns. By way of non-limiting example, the signaling data may be a full or complete transmission bandwidth, guard band length for training patterns, location of each signaling pattern in a frame, guard band length for signaling patterns, guard band length for data patterns The number of frames constituting the super frame, the number of current frames in the super frame, the number of data patterns in the frequency dimension of the overall frame bandwidth, the additional data patterns in the time dimension of the frame, and / or each of the respective frames Parameters such as the number of individual signaling data for a data pattern. Accordingly, the location of each signaling pattern in the frame may indicate the location of the signaling pattern, for example with respect to training patterns or with respect to the division of the overall bandwidth. For example, in the case of FIG. 10 where the signaling patterns have the same length as the training patterns and are aligned with the training patterns, the signaling data may be defined in that the signaling pattern is the first segment (eg, the first 8 MHz segment) or the first. It includes an indication of whether it is located in two segments or the like. For example, as described with respect to FIG. 13, when the signaling patterns have half the length of the training patterns, each pair of adjacent signaling patterns has the same location information. In either case, the receiving device may use this location information to tune to the desired frequency band in subsequent frames. The individual signaling data is a separate block of data provided separately for each data pattern present in the frame, the first frequency carrier of the data pattern, the number of frequency carriers assigned to the data pattern, the modulation used for the data pattern, the data Error prevention code used in the pattern, use of the time interleaver for the data pattern, number of frequency notches (frequency carriers not used for data transmission in the data pattern), location of frequency notches and / or Parameters such as width of frequency notches. The signaling mapping means 57 of the transmitting device 54 is adapted to map the corresponding signaling data on the frequency carriers of each signaling pattern. The evaluation means 67 of the receiving device 63 is adapted to evaluate the received signaling data and to use or convey the information contained in the signaling data for further processing in the receiving device 63.
When signaling data includes the individual signaling information for each data pattern present in a frame, the structure of the signaling patterns is determined by the maximum of data patterns per frame in the frequency direction to limit the size of each signaling pattern to the maximum size. Support limit number. Thus, the number of data patterns in the frequency direction of each frame can be changed dynamically and flexibly, but this will only be true within a certain maximum number of data patterns. The additional data patterns in the time direction of each frame are each aligned with the preceding data patterns as described above. Thus, each additional subsequent data pattern has the same position, length, modulation, and the like as the preceding data pattern, so the signaling data for the preceding data pattern is valid for the subsequent data pattern as well. Accordingly, the number of additional data patterns in the time direction of each frame may be fixed or invariant, and such information may be included in the signaling data. Similarly, the structure of the signaling patterns can only support the maximum limit number of frequency notches in each data pattern.
Alternatively or in addition, in order to overcome the problem that portions of the signaling patterns 31 may not be received at the receiving device 63, the transmitting device 54 is optionally signaled by the signaling mapping means 57. Error coding means 56 adapted to add some kind of error coding, such as repetitive coding, cyclic redundancy coding, or the like, to the signaling data mapped on the frequency carriers of the pattern. An additional error coding means will enable the transmitting device 54 to use signaling patterns 31 of the same length as the training patterns 30 as shown in FIG. 10, which the receiving device 63 may use as an example. This is because the original signaling pattern can be reconstructed by performing a certain kind of error detection and / or correction through the reconstruction means 71.
For the above example where the signaling patterns have a length of 4 MHz in the OFDM system and are aligned to the training patterns (segments) of 8 MHz, the table below shows a specific (non-limiting) example of the signaling structure.
Table 1: Signaling Structure
n4k n 4 bits n4k current n 4 bits Guard interval length 2 bits Superframe length 16 bit Frame number 16 bit Number of data patterns 5 bits (or 4 or 6 bits) Loop through data patterns with individual information about each data pattern n-segment number 4 bits Start carrier number 12 bit Data pattern width (number of carriers) 12 bit Data Pattern QAM Modulation 3 bits LDPC block size 1 bit LDPC code rate 3 bits Time interleaver 1 bit Number of notches 2 bits Loop through notches { Start carrier number 12 bit Notch width (number of carriers) 12 bit } End the notch loop PSI / SI reprocessing 1 bit } End the data pattern loop reservation 1 bit (or 0 or 2 bits) CRC_32 MIP 32 bit
Advantageously, the frame structure can have up to 32 data patterns per frame in the frequency dimension, so in a system with an overall bandwidth of 32 MHz (four times the training pattern length of 8 MHz), each data pattern is 1 MHz. Has a minimum length. The maximum size of the resulting signaling pattern is (48 + 32 + 32 (36 + 4 * 24)) = 48 + 32 + 4224 = 4304 bits. Appropriate shortened Reed Solomon coding may be applied to the signaling data. The encoded data may for example be mapped onto two consecutive QPSK symbols, or any other suitable modulation may be used.
Alternatively, the frame structure can have up to 64 data patterns per frame in the frequency dimension, so in a system with an overall bandwidth of 32 MHz (four times the training pattern length of 8 MHz), each data pattern is 0.5 MHz. Has a minimum length. The maximum size of the resulting signaling pattern is (48 + 32 + 64 (36 + 4 * 24)) = 48 + 32 + 8448 = 85284 bits. Appropriate shortened Reed Solomon coding may be applied to the signaling data. The encoded data may for example be mapped onto two consecutive 16-QAM symbols, or any other suitable modulation may be used.
Alternatively, the frame structure may have up to 16 data patterns per frame in the frequency dimension, so in a system with an overall bandwidth of 32 MHz (four times the training pattern length of 8 MHz), each data pattern is 2 MHz. Has a minimum length. The maximum size of the resulting signaling pattern is (48 + 32 + 16 (36 + 4 * 24)) = 48 + 32 + 2112 = 21924 bits. Appropriate shortened Reed Solomon coding may be applied to the signaling data. The encoded data may for example be mapped onto one QPSK symbol, or any other suitable modulation may be used.
In the following, the parameters of the signaling data mentioned in Table 1 above are described in more detail.
a) n of n4k: defines the total transmission bandwidth of the proposed 4nk symbol as a multiple of 8 MHz.
n = 1: 8 MHz
n = 2: 16 MHz
n = 3: 24 MHz
n = 4: 32 MHz
b) current n of n4k: indicates the location of the decoded signaling pattern in the complete 4nk channel (frame).
0000 reservation
0001 0 ... 8 MHz (n = 1)
0010 8 ... 16 MHz (n = 2)
0011 16 ... 24 MHz (n = 3)
0100 24 ... 32 MHz (n = 4)
c) Guard Interval Length: Defines the length of guard intervals (or bands) for all data patterns as well as signaling patterns.
00 GI = 1/64
01 GI = 1/128
10 GI = 1/256
d) Superframe Length: This parameter describes the number of frames that make up one superframe.
e) Frame number: Allow frame counting in one superframe. At the beginning of each superframe, this counter is reset.
f) Number of data patterns: Define the number of frequency patterns in the overall channel bandwidth.
g) n-segment number: This parameter signals the position of the first carrier (ie, 8 MHz segment) of the data pattern.
h) Start Carrier Number: Defines the first carrier of the data pattern. Numbering is relative to the frame of the associated 8 MHz segment.
i) Data pattern width: defines the number of carriers allocated for the data pattern.
j) Data Pattern QAM: This parameter indicates the QAM modulation for the data pattern.
000 16 QAM
001 64 QAM
010 256 QAM
011 1024 QAM
100 4096 QAM
101 16384 QAM
110 65536 QAM
k) LDPC block size: Defines the LDPC block size.
0 16k block size
1 64k block size
l) LDPC code rate: Defines the low density parity check (LDPC) code rate selected for the data pattern.
0110-1111 Reserve
m) Time Interleaver Capable: Signals the use of a time interleaver for this data pattern.
n) Number of Notches: Defines the presence or number of notches in this data pattern.
00 No notch in this data pattern
01 one notch in this data pattern
10 2 notches in this data pattern
11 3 notches within this data pattern
o) Notch Start: Defines the first carrier of the data pattern.
p) Carrier Number: Numbering is relative to the frame of the associated 8 MHz segment.
q) Notch Width: Defines the number of carriers allocated for the notch.
r) PSI / SI reprocessing: Signals whether PSI / SI reprocessing is performed within the headend.
0 PSI / SI reprocessing not possible
1 PSI / SI reprocessable
s) CRC_32 MIP: 32-bit CRC coding for L1 signaling block
In order to ensure even better reception of the signaling patterns at the receiving device 63, the present invention further proposes to optimize the tuning position of the receiving device 63. In the examples shown in FIGS. 10 and 13, the receiver is tuned to the portion 38 by centering the portion 38 of the transmission bandwidth around the frequency bandwidth of the data patterns to be received. Alternatively, the receiving device 63 may be tuned so that the reception of the signaling pattern 31 is optimized by placing the portion 38 such that the maximum portion of the signaling pattern 31 is received while still sufficiently receiving the desired data portion. Alternatively, the present invention suggests that the length of each data pattern will not differ by a certain percentage, for example more than 10%, from the length of each preamble patterns 30 and signaling patterns 31. An example of such a solution can be found in FIG. 14. The boundaries between the data patterns 42, 43, 44, 45 are equal to, but not limited to, 10% from the boundaries between the preamble patterns 30 and the signaling patterns 31 (in the frequency direction). It does not deviate by more than a certain percentage. This small percentage can then be corrected by the additional error coding described above in the signaling patterns 31.
16 shows a time domain representation of an example of a frame 47 in accordance with the present invention. In the transmitting device 54, after the frame pattern or structure is generated in the frame forming means 59, the frequency domain frame pattern is converted into the time domain by the converting means 60. An example of the resulting time domain frame is now shown in FIG. 16. Frame 47 comprises a number of shortened training symbols 48 resulting from mapping only on every mth frequency carrier (m is a natural number of two or more) of pilot signals by pilot mapping means 55, followed by a guard. And a plurality of data symbols 52 separated by an interval 49, a signaling symbol 50, an additional guard interval 51, and guard intervals 53, respectively. The situation where only a single signaling symbol is present in the time domain corresponds to the example shown in FIG. 10 where only a single time slot with signaling patterns is present in the frequency domain frame structure, but 2 with signaling patterns 31a and 31b respectively. The example of FIG. 13 with two time slots would have two signaling patterns in the time domain, which are eventually separated by guard intervals. The guard intervals may for example be circular extensions of the useful parts of the respective symbols. Synchronization reliability can generally be improved by inverting the final training symbol, i.e., by inverting the phase of the last training symbol with respect to preceding training symbols (all having the same phase). In an example of an OFDM system, the signaling symbols and data symbols including the finally provided guard bands each have a length of one OFDM symbol. The time domain frames are then delivered to the transmitting means 61 for processing the time domain signal according to the multi-carrier system used, for example by upconverting the signal to the desired transmission frequency. The transmission signals are then transmitted via transmission interface 62, which may be a wired interface or a wireless interface such as an antenna or the like.
The number of shortened training symbols 48 in frame 47 depends on the desired implementation and transmission system used. As a non-limiting example, the number of shortened training symbols 48 may be eight, which is a good compromise between correlation complexity and synchronization reliability.
16 further shows that each number of frames can be combined into superframes. The number of frames per superframe, ie the length of each superframe in the time direction, may be constant or vary. Accordingly, there may be a maximum length over which superframes can be set dynamically. It may also be advantageous that the signaling data in the signaling patterns for each frame in the superframe are the same, and that changes in signaling data occur only between the superframes. That is, the modulation, coding, and number of data patterns are the same in each frame of the superframe, but may be different in subsequent superframes. For example, in broadcast systems the length of superframes may be longer because signaling data may not change often, and in interactive systems the superframe length may be such that the optimization of the transmission and reception parameters is dependent on feedback from the receiver to the transmitter. It can be made on a basic basis and therefore shorter.
The elements and functions of the transmitting device 54 of the block diagram shown in FIG. 17 have been described above. It should be understood that the actual implementation of the transmitting device 54 will include additional elements and functions necessary for the actual operation of the transmitting device in each system. 17, only elements and means necessary for the explanation and understanding of the invention are shown. The same applies to the receiving device 63 in the block diagram shown in FIG. 18 illustrates only elements and functions necessary for the explanation and understanding of the present invention. Additional elements will be needed for the actual operation of the receiving device 63. It should be further understood that the transmitting device 54, as well as the elements and functions of the receiving device 63, may be implemented in any kind of device, apparatus, system, etc., adapted to perform the functions described and claimed by the present invention. .
The invention also provides a frame structure (and correspondingly) in which at least one data pattern has a plurality (more than one) of data patterns having a length different from that of the other data pattern (s) as an alternative to the above-described embodiments. Transmitting and receiving apparatus and method as described above). The structure of such variable length data patterns is a sequence of training patterns having the same lengths and content as described above, or at least one training pattern different in length and / or content from other training patterns, i.e. a variable training pattern. It can be combined with a sequence of training patterns having a length. In both cases, the receiving device 63 may have a predetermined value for a variable data pattern length that may be transmitted through a separate signaling data channel or through signaling data included in signaling data patterns included in the frame structure as described above. You will need information. In the latter case, the first training pattern and the first signaling pattern in each frame always have the same length, so that the receiving device receives the first training patterns and the signaling patterns in all or the required frame so that the variable data patterns can be changed. There may be one possible implementation where information is always available. Of course, other implementations may be possible. Otherwise, the remainder of the above description relating to training patterns, data patterns and signaling patterns as well as possible implementations at the transmitting device 54 and the receiving device 63 is still applicable.
1. Implementation Outline
The following description is a proposal for a beneficial implementation of the present invention in a future cable based digital video broadcasting system such as but not limited to DVB-C2. Recent developments in second-generation physical layer standards for satellite (DVB-C2) and terrestrial (DVB-T2) transmissions are being enhanced for digital broadcast and interactive services that can be achieved using the current first-generation DVB-C standard. Cable operators are needed to provide competitive technical performance and flexibility. The purpose of this proposal is to provide a complete system solution to the current and anticipated future needs of cable networks, but can also be applied to terrestrial networks.
This proposal allows for significant improvements in throughput and system flexibility through a number of new and improved features.
Flexible and highly efficient OFDM modulation scheme:
In addition to the existing 8 MHz frequency raster, the use of larger bandwidths with a certain multiple of 8 MHz allows a very spectrum efficient transmission system to be realized.
Reception based on frequency slices to allow for cost effective receiver implementation and improved system flexibility.
(Security related) Notching of OFDM subcarriers to support efficient protection of terrestrial services (cumulative radiation of cable networks disturbs terrestrial services).
Higher order modulation of OFDM subcarriers currently provides a significant increase in throughput over DVB-C systems.
Up to 69.8 Mbit / s (at 8 MHz receive bandwidth) using 1024 QAM subcarrier modulation.
Up to 83.7 Mbit / s (at 8 MHz receive bandwidth) using 4096 QAM subcarrier modulation.
LDPC codec reused from DVB-S2 and DVB-T2 with code rates optimized for cable systems provides more than 3 dB of gain through current coding and facilitates compatibility with second generation DVB systems.
• Supports transcoding of satellite and terrestrial services into cable systems.
Supports multiple input stream formats (single and / or multiple transmission streams (TS) and general stream encapsulation (GSE)).
Throughput optimization when return channels are available.
Low system latency to support interactive services.
Adaptation of OFDM subcarriers to optimize throughput according to SNR conditions unique to position and frequency slices.
This proposal is a complete system proposal and addresses all aspects of the needs. A detailed comparison of the C2 related requirements is provided with the technical description in paragraph 5.
AWGN: Additional White Gaussian Noise
BCH Code: Bose-Chaudhuri-Hocquenghem Multiple Error Correction Binary Block
CAZAC: Constant Amplitude Zero Autocorrelation Waveform
GS: General Stream
GSE: Encapsulating Generic Streams
LDPC: Low Density Parity Check Code
PAPR: Peak-to-Average Power Reduction
PSI / SI: Program Specific Information / Service Information
TS: Outgoing Stream
All functions and requirements described below are respectively suitable means and elements of the transmitting device 54 shown in FIG. 17 and described in connection with and / or the receiving device 63 shown in FIG. 18 and described in connection with it. It can be implemented in It is also to be understood that the following detailed description of advantageous implementations is not intended to limit the scope of the invention as defined in the claims.
2.1. Flexible n4k system
The proposed system includes a high level of flexibility regarding the mapping on OFDM subcarriers of different input formats (single / multiple TS and GSE).
The basic concept is to bundle and multiplex as many input streams as possible on an associated number of OFDM subcarriers that do not overall exceed the maximum tuner bandwidth (e.g. 8 MHz including associated guard bands) at the receiving end. It is. This is defined as a frequency data slice.
The subchannels represent one 8 MHz bandwidth block of the existing cable channel raster. The current DVB-C bandwidth (ie 8 MHz) can be used on a single channel. However, to further improve spectral efficiency, n 8 MHz wide OFDM subchannels can be combined or "bundled" together to create a larger channel. Multiple frequency data slices can be combined in one channel. There is no fixed frequency bandwidth allocation for frequency slices and they need not be aligned to 8 MHz subchannels.
Since the guard bands of the OFDM spectrum are used only once on each side of the overall channel bandwidth, the spectral efficiency is improved. The spectral shaping of the guard band does not change with different channel bandwidths. 19 shows different channel bandwidth examples with associated guard bands.
19: Example Bandwidths of the Proposed DVB-C2 OFDM Channels
It is clear that the greater the overall channel bandwidth, the lower the spectral overhead of the guard bands. The upper limit of the overall channel bandwidth depends on the technology available on the headend side (D / A converter). Table 2 shows the overhead percentages for different OFDM spectral bandwidths when the same guard band shaping is applied.
Table 2: Guard Band Overhead for Different OFDM Spectrum Bandwidths
OFDM channel bandwidth Guard band overhead 8 MHz 5.1% 16 MHz 2.5% 24 MHz 1.7% 32 MHz 1.2% ... ...
The frequency data slice bandwidth is not associated with any fixed frequency raster and can be adjusted in a simple manner according to the bandwidth requirements of the input streams. The only requirement is that the number of subcarriers allocated should not exceed the tuner bandwidth on the receiving side. Statistical multiplexing is applied to the data slice and benefits from the largest possible bandwidths.
The total channel bandwidth must be a multiple of n of the subchannel raster (8 MHz). This enables simple network planning as well as sufficient high tuning step sizes in the receiver tuner. OFDM modulation is derived from the 4k mode of operation used in DVB-H / T2 and extends to multiples of the subchannel raster. Thus, such a system is referred to as an n4k system, where n represents the number of bundled 4k modulation blocks.
2.2. Partial OFDM Receive
In order to enable a cost effective receiver implementation, OFDM reception based on frequency slices is proposed.
Segmented OFDM reception with a fixed segment size has already been successfully deployed in current ISDB-T. In such systems it is possible to receive individual segments or combined segments. The main application in ISDB-T is to provide mobile reception as well as fixed terrestrial reception within one RF channel.
The proposed C2 system includes the assignment of arbitrarily adjustable subcarrier blocks as shown in FIG. The proposed C2 headend can calculate the input stream inherent distribution and frequency slice assembly of all OFDM subcarriers for each superframe. Ideally, each input stream or each group of input streams is mapped on an associated subgroup of OFDM subcarriers. The number of subcarriers allocated can be derived directly from the input data rate. This includes the combined overhead of mode adaptation, stream adaptation and FFC encoding and the gains due to QAM modulation. The division of the entire OFDM channel into different frequency slices (also called frequency patterns or segments) is defined by L1 signaling (section 3.7.2). The receiver is tuned to the frequency containing the desired frequency data slice. Partial OFDM modulation is applied to the selected 8 MHz receive spectrum.
20: Partial reception of wider OFDM transmission signal
Note: The width of the frequency data slice may be less than the reception bandwidth at the time of reception. In this case, the receiver selects only the information of the relevant subcarriers after OFDM modulation and passes them to the next decoding sections.
2.3. C2 system overview
21 below shows a top layer block diagram of a proposed C2 system.
Figure 21: Top layer block diagram of the proposed C2 system
In a first step in the proposed transmission system, different input streams (single or multiple TS or GS) are merged and packetized into baseband packets similar to DVB-S2. This kind of mode adaptation allows for stream specific (i.e., TS or GS) adjustment of the desired robustness level. It is possible to supply a single TS or GS on a rather small number of OFDM subcarriers. However, in order to increase the diversity of the subchannels (i.e. by applying frequency interleaver on a larger number of subcarriers), as many input streams as possible to access the maximum possible bandwidth (i.e. tuner bandwidth at the receiving end) are obtained. It is advantageous to bundle.
The next step is a stream adaptation step that performs padding (if needed) and applies baseband scrambling before FEC encoding is applied.
The FEC encoding step includes a BCH encoder, LDPC encoder, as well as a bit interleaver unit, similar to those used in DVB-T2. The normal output block size of the LDPC encoder is 64800 bits. However, to support low latency (eg, as required by interaction services), smaller LDPC block sizes (ie, 16200 bits as known from DVB-T2) are also supported. In order to eliminate error floors for high QAM constellation (more than 1024 QAM), a coordinated BCH with t-error correction of 12 bits is used.
Subsequently, LDPC encoded FEC frames enter the BICM (Bit Interleaved Coded Modulation) step. Here, the output of the LDPC encoder is bit interleaved as in DVB-T2, and is connected by column twist interleaving and parity interleaving followed by a demultiplexer. Bit interleaver extensions for new, higher QAM constellations are included in this document. The QAM encoder then maps the input bits to complex QAM symbols. QAM mapping is based on gray coding and an extension of T2 mapping for 1024 QAM and 4096 QAM is proposed.
Modulation and FEC parameters can be changed to provide flexible settings to meet different needs and environments. The proposed system provides two different modes of operation.
For broadcast systems, the settings of modulation and coding for each data slice (ie, an associated number of OFDM subcarriers) are adjusted only at the transmitting side. The settings are chosen to ensure the desired quality of service level within the entire network. The modulation and coding for each data slice can be changed between superframes. Each subcarrier in a data slice (also called a data pattern or segment) has the same modulation and coding.
If the cable network provides a return channel, the receiver may inform the transmitter of its SNR condition to optimize the selected modulation and coding. This is particularly important for optimizing the throughput of point-to-point interaction services (IP based, for example DOCSIS Internet traffic or Video on Demand (VoD)). If the transmitter chooses modulation and coding according to the receiver with the overall worst SNR for the relevant data slice, fewer multicast connections may also benefit from the SNR information.
The next step is a time interleaver that can eliminate the effects of impulsive noise and other noise bursts. The time interleaver is aligned to the full frame length and can be switched off for time critical services such as interaction services that require low latency.
Frequency interleaving is used to average the SNR ripple over the frequency slice width. The basic architecture is based on the frequency interleaver from DVB-T and DVB-T2, but the width of the frequency interleaver is variable and matches the number of subcarriers allocated by a particular data slice. Frequency interleaver specific memory mapping and demapping at the transmitter as well as at the receiver can be easily performed during operation. The output signal of each symbol interleaver is then mapped to one data slice (also called a data pattern). The OFDM symbol builder combines all the different input streams by mapping all the different input streams to the required number of subcarriers, including the insertion of the appropriate pilot pattern.
The total number of subcarriers for one OFDM symbol increases with increasing number of bundled 8 MHz channels (n4k system). The alignment of these data slices does not have any segmentation restriction as shown in FIG. The only requirement is that the width of one data slice (i.e. the number of subcarriers allocated) must not exceed the receiver bandwidth (i.e. 8 MHz, the passband bandwidth of each receiver front end).
Figure 22: Data slicing over full channel bandwidth (32 MHz channel example)
The proposed frequency slicing provides a very efficient mapping on the overall large bandwidth of the bandwidth requirement accumulation of all the different input streams without any large stuffing overhead.
The guard interval is then pre-pended to each OFDM symbol. This document proposes three different guard interval lengths to provide the possibility to optimize the guard interval for a network specific environment (ie, maximum echo length).
In the final framing section, each of the 320 data OFDM symbols contains the training sequence phase (allowing all the important synchronization as well as the initial channel estimation functions) and two 16 QAM modulated L1 signaling symbols (all important physical layer information for the upcoming frame). Separated by a preamble.
2.4. DVB-S / DVB-S2 Service Transcoding
For transcoding satellite streams into C2 cable networks, the block diagram of FIG. 21 is typically valid, and the TS level is used as the interface between satellite decoding and C2 native encoding. Thus, TS-based output streams of the DVB-S system are encoded according to higher signal chains.
In order to perform the correct adaptation of all PSI / SI information entries in all transmission streams, an additional PSI / SI reprocessing block is included at the beginning of the proposed C2 encoding.
Figure 23: VDB-S (2) Transcoding: An interface is a TS level that includes PSI / SI processing.
Note: The same TS-based reprocessing may be applied to transcode DVB-T or DVB-T2 transmission streams into the cable network.
For SMATV headends that transcode DVB-S2 services into smaller cable networks, PSI / SI processing may not apply (similar to DVB-C SMATV systems). In this case, it is not necessary to invert all encoding steps to insert signals into the cable network. Moreover, DVB-S2 signals are only decoded up to baseband packet levels. These baseband packets are then inserted directly into the proposed C2 system. 24 shows a related block diagram.
Figure 24: Block diagram of the SMATV headend: Baseband packets of DVB-S2 services are used as input data.
3.1. Mode adaptation
Mode adaptation is reused as much as possible from DVB-S2. The system operates according to either the transmission stream input or the general stream input (DVB GSE protocol for adapting the IP stream to the general stream). Both formats support single and multiple input stream modes as shown in FIG.
This kind of mode adaptation enables stream specific (i.e., TS or GS) adjustment of the desired robust level. The larger the SNR, the higher the 'ModCod' mode is used (ie the combination of modulation scheme and selected FEC mode).
In cable channels, SNR fluctuation levels are limited compared to terrestrial systems. Thus, the emphasis on this proposal is to simplify and reduce signaling overhead.
Similar to DVB-S2, various stream configurations are supported to provide the necessary system flexibility.
Single Transmission Stream Input (CCM): All services in the input stream are protected by the system at the same FEC level. VCM cannot be used directly at a single transmission stream level.
● Multiple transmission stream inputs (CCM and VCM)
Each transmission stream can be individually protected to a single FEC level.
O Protection may be differentiated in different transmission streams (VCM).
Figure 25: Mode adaptation for DVB-C2 supporting single and multiple input streams (TS or GS)
3.2 FEC Encoding
3.2.1. BCH
BCH encoding is performed according to DBV-S2. The use of 12 error correction BCH is proposed for all code rates to avoid the high error floor that appears for higher order modulations (1024 QAM, 4096 QAM) proposed for DVB-C2.
Table 3: Coding Parameters (n ldpc = 64800 for Normal FEC Frame)
Table 4: Coding Parameters (n ldpc = 16200 for short FEC frame)
3.2.2. LDPC
LDPC encoding is performed according to DVB-S2. The block size of the LDPC codec is N ldpc = 16200 or 64800.
3.2.3. Interleaver
3.2.3.1 Bit Interleaver
The bit interleaver will be used to optimize the allocation between LDPC code bits and gray mapped QAM symbol bits. As in DVB-T2, this will consist of a block interleaver and a demultiplexer.
In the block interleaver portion as shown in FIG. 26, the output of the LDPC encoder will be first parity interleaved and then stored in memory of N c columns and N r rows. The data is written in columns and read in rows according to the column twisting offset t c .
Figure 26: Bit interleaving scheme
The output N c tuples {b 0 , r , b 1 , r , b 2 , r , ..., b Nc -1 , r } for the r th row are {y 0 , r , y 1 , r in the demultiplexer part. , y 2 , r , ..., y Nc -1 , r }, and each m bit belongs to a 2 m QAM symbol.
In addition to DVB-T2 constellations, 1024 QAM and 4096 QAM are proposed for broadcast services. The necessary parameters are shown in Tables 5, 6 and 7.
Table 5: Bit Interleaver Structures (1024 QAM, 4096 QAM)
Table 6: Column Twisting Parameters (t c ) (1024 QAM, 4096 QAM)
Table 7: Parameters for Demultiplexing of Bits into Cells for Rates 2/3, 8/9, and 9/10
Table 8: Parameters for Demultiplexing Bits into Cells for Rates 3/4, 4/5, and 5/6
3.2.3.2. Time interleaver
In order to mitigate the impact from impulse or burst noise, a time interleaver is proposed for broadcast services. The interleaving length of the time interleaver is kept short compared to DVB-T2.
27 illustrates time interleaver operation. The time interleaver takes the output from the QAM encoder and writes the data into the columns. The outputs are passed to the frequency interleaver by reading the interleaver cells in the rows.
The number of rows R is a fixed value of 40; This value represents an erase rate of 2.5%, i.e. approximately one in every 40 symbols is lost due to interference.
The time interleaver length is aligned to the frame length (section 7.5) for simplicity.
The number of columns N L in the time interleaver matches the number of subcarriers in the required service.
The use of time interleaving for each block of the segmented OFDM system is signaled within the L1 packets.
● Transmitter memory requirement: 4096 * 12 * 40 = 1966080 = 1.97 Mbit
An exemplary interferer can be considered to be a 577 μs burst received from a GSM mobile phone. This duration corresponds to approximately one n4k symbol period. Depending on the strength of the cancellation, a 9/10 code rate or more robust code rate may be used for the LDPC encoder.
Figure 27: Time interleaver
Time interleaving will be optional for interactive services using (adaptive OFDM).
Services with high QoS and low latency requirements (eg VoD) should use time interleaving.
• Services that require low latency (eg gaming, TCP / IP based) should not use time interleaving.
3.2.3.3. Frequency interleaver
In general, the frequency interleaver will be used similar to DVB-T2. Since variable frequency slices are allowed for OFDM reception, the interleaver size must be calculated dynamically by the transmitter as well as by the receiver (ie, the interleaver size varies with the number of subcarriers allocated).
The purpose of a frequency interleaver operating on data cells of one OFDM symbol is to map the data cells onto N data available data carriers in each symbol. The frequency interleaver processes the data cells X m , l = {(x m , l , 0 , x m , l , 1 , ..., x m , l , Ndata -1 ) of OFDM symbols l of C2-frame m something to do.
The parameter M max is then defined according to table 8.
Table 8: Value of M max for frequency interleaver
FFT size M max 4k 4096
The interleaved vectors A m , l = (a m , l , 0 , a m , l , 1 , a m , l , 2 , ..., a m , l , Ndata -1 ,) are defined by .
q = 0, ..., N a m , l , H (q) = x m , l , q for even symbols (l mod 2 = 0) of the frame for data -1
q = 0, ..., N a m , l , q = x m , l , H (q) for odd symbols (l mod 2 = 1) of the frame for data -1
H (q) is a substitution function based on the sequences R ' i defined as follows. The (N r -1) bit binary word R ' i is defined, N r = log 2 M max , and R' i has the following values.
i = 0,1: R ' i [N r -2, N r -3, ..., 1,0] = 0,0, ..., 0,0
i = 2: R ' i [N r -2, N r -3, ..., 1,0] = 0,0, ..., 0,1
2 <i <M max : {R ' i [N r -3, N r -4, ..., 1,0] = R' i -1 [N r -2, N r -3, ... , 2,1];
In 4k mode,
The vector R i is derived from the vector R ' i by the bit substitutions given in Table 9.
Table 9: Bit substitution
R ' i locations 10 9 8 7 6 5 4 3 2 One 0 R i locations 7 10 5 8 One 2 4 9 0 3 6
The substitution function H (q) is defined by the following algorithm.
A schematic block diagram of the algorithm used to generate the substitution function is shown in Figure 28: Frequency interleaver address generation scheme for 4k mode.
Figure 28: Frequency interleaver address generation scheme for 4k mode
The output of the frequency interleaver is the data cells A m , l = (a m , l , 0 , a m , l , 1 , a m , l , 2 , ..., a m , l , for symbol l of frame m. Is an interleaved vector of Ndata -1 ,).
N data is signaled in the L1 symbols.
3.3. QAM subcarrier modulation
The modulation of the OFDM subcarriers will be normal quadrature amplitude modulation.
(QAM): The use of the following constellations is proposed based on the definitions of DVB-T2.
● 16 QAM
● 64 QAM
● 256 QAM
In order to increase the throughput rate of the proposed C2 system, the following higher constellations are proposed for broadcast services.
● 1024 QAM (using gray mapping)
● 4096 QAM (using gray mapping)
In addition, much higher QAM constellations can be applied for interactive services that can take advantage of adaptive coding and modulation (ACM), i. Exchange signaling OFDM tonemaps. SNR dependent adjustment of the selected constellation and coding is possible.
3.4. OFDM parameters
This chapter proposes an OFDM structure for use for each transmission mode. The transmitted signal is organized into frames as described in section 3.5. Each frame has a duration of T F and consists of L F OFDM symbols. Each symbol consists of a set of K carriers transmitted with a duration T S. It consists of two parts, the useful part with duration T U and the guard interval with duration Δ. The guard interval consists of a circular sequence of useful parts T U , inserted before it. Symbols in an OFDM frame are numbered from 1 to L F. Every symbol contains data and / or reference information.
Since an OFDM signal includes many individually modulated carriers, each symbol may be considered to be divided into cells, each corresponding to a modulation performed on one carrier during one symbol.
OFDM symbols include pilots that can be used for frame synchronization, frequency synchronization, time synchronization, channel estimation, and can also be used to track phase noise. Carriers are k∈ [K min ; k max ], K min And K max . The spacing between adjacent carriers is 1 / T U , while the spacing between carriers K min and K max is determined by (K-1) / T U.
OFDM parameters are summarized in Table 10. The values for the various time related parameters are given in multiples of the base period T and in microseconds.
The n4k mode of operation is proposed as a good trade-off between symbol length, phase noise sensitivity as well as spectral side lobe steepness. This is based on the DVB-H / T2 4k mode in the 8 MHz channel. System bandwidth can be extended to n times 8 MHz. The following table shows the settings for different channel bandwidths, where n varies from 1 to 4.
Table 10: 4nk OFDM Modulation for Different Channel Bandwidths
As an added benefit of channel bundling, the proposed OFDM values are very similar to the main parameters of DVB-H / T2 4k mode, including the carrier interval as well as the symbol duration.
Note: Other channel bandwidths can be obtained by adjusting the base period T. For example, by changing the base period from 7/64 μs to 7/48 μs, a 6 MHz channel bandwidth can be derived from an 8 MHz channel.
3.5. Framing
The framing structure is shown in FIG. 29 similar to FIG. 16 described above. The superframe is divided into C2 frames, and the C2 frames are further divided into OFDM symbols. The C2 frame starts with one preamble symbol, followed by two layer 1 signaling symbols, and finally L F -3 data symbols.
29: C2 frame structure
Except for the preamble symbols having a duration T u (no guard interval), the duration of each symbol in the frame has the same duration T s . The symbol period T s consists of the sum of the guard interval duration T GI and the useful symbol duration T u .
The number of data symbols is fixed at 8 * time interleaver (section 3.2.3.2) symbol length = 8 * 40 = 320 symbols. The C2 frame has a total of L F = 323 symbols consisting of 320 data symbols, one preamble symbol (no guard interval) and two L1 signaling symbols. Thus, the overhead for signaling is 3/323 (about 0.9%) for the preamble and L1 signaling symbols.
The proposed C2 frame period is T F = 322 * (T GI + T u ).
Table 11: Frame Periods of the 4nk System for Different Guard Interval Lengths
Guard interval length Frame duration 1/64 147.0 msec 1/128 145.8 msec 1/256 145.3 msec
The duration of the C2 superframe is in the range 1 * T F <= T SF <= (2 16 -1) * T F.
L1 signaling data may be changed only at superframe boundaries. In broadcast only services, the superframe period may be set to its maximum value of (2 16 -1) * T F , which is about 2 hours 37 minutes when assuming that the L1 signaling parameters do not change often. In interactive only or mixed broadcast / interactive services, the superframe length can be shortened as needed. The superframe period is provided as the L1 signaling parameter.
The zapping time in the absence of knowledge of the frequency data slice position is expected to require up to two complete C2 frame periods (288 ms) depending on the relative timing of the start of the channel change relative to the start of the C2 frame. .
3.6. Pilot Carriers in Data Symbols
The scattered pilot density is derived from
Maximum delay length of the multipath channel to determine the repetition rate in the frequency direction
Maximum Doppler frequency of the cable channel to determine the repetition rate in the time direction
Since the cable channel is considered quasi-static in the time direction, the repetition rate can be kept low. To optimize pilot pattern overhead, the density of the scattered pilot pattern depends on the guard interval size. The following pilot patterns are proposed.
Table 12: Scattering Pilot Patterns for the Proposed C2 System
OFDM mode Guard interval length Spacing of pilot holding carriers (x) The number of symbols (y) forming one scattering pilot sequence n4k 1/64 4 12 n4k 1/128 4 24 n4k 1/256 4 48
Table 12 shows the frequency shift of the pilot position after one symbol becomes four carriers. The repetition rate in the frequency direction is x.y (eg 48 carrier distances for GI = 1/64).
30 shows the pilot pattern (black dots) for guard interval length of 1/64.
Fig. 30: File pattern example (GI length = 1/64)
The first as well as the last carrier of each OFDM symbol will always contain pilot carriers. According to the Nyquist criterion, independent frequency interpolation is possible for each OFDM symbol itself. However, by applying additional time interpolation, it is possible to improve the channel estimation quality.
Since time interpolation is generally not necessary, continuous pilots (CPs) are also not needed. To calculate the common phase error (CPE), it is sufficient to consider only frequency interpolated channel estimates.
3.7. Preamble
The preamble defines the start of a new C2 frame. The preamble shall allow the following functions.
Frame and Initial OFDM Symbol Synchronization
Initial offset correction (frequency and sampling rate offsets)
● initial channel estimation
Information about basic physical layer parameters for the next frame
○ Guard Interval
○ OFDM subcarrier allocation
■ basic structure for different subcarrier segments
● Start / stop carrier, block width, ...
Segment-specific subcarrier modulation
Segment-specific subcarrier FEC settings
○ frequency notch indication
The preamble is divided into a training sequence phase and an L1 signaling phase. The training phase consists of eight shortened training symbols, with a total length of 1 OFDM symbol (4096 samples). The two following OFDM symbols include L1 signaling (including the associated guard interval).
FIG. 31 shows the basic structure of one C2 frame (in the time domain), and FIG. 32 similar to FIG. 13 described above shows the basic structure of one C2 frame in the frequency domain.
31: Time domain frame structure of the proposed DVB-C2 system
32: Frame structure and alignment of preamble and data portion (32 MHz example)
The proposed preamble provides all the important important functions regardless of the tuning position.
● Time / frame synchronization
Approximate / precise frequency offset estimation
L1 signaling
The ability to perform all preamble functions regardless of the tuning position enables the use of arbitrary data slicing in the frequency domain. In particular, the width (bandwidth) of the data slices need not be aligned to any fixed segment size. The function of the different blocks is described below.
3.7.1. Shortened training symbols
The bandwidth of the preamble sequence is limited to the reception bandwidth (ie 8 MHz) of the segmented receiver. The total channel bandwidth of the transmitted signal is a multiple of this receiver bandwidth (ie tuner bandwidth). The density of pilot carriers in the training symbols is adjusted to fulfill at least the Nyquist criterion. For n4k mode, the following preamble is proposed.
8 shortened training symbols (interval of pilot carriers = 8)
Repetition rate of short training symbols: 512 samples
Each training sequence subblock is equal to the initial receiver bandwidth and includes repetition of a basic pseudo noise sequence with optimized correlation characteristics, which provides several benefits.
If the receiver tuner selects a window that matches one of the equidistant segments of the wider transmission channel bandwidth, the training sequence is developed in a sufficiently and optimized manner.
If the tuner selects any tuning frequency within the transmission channel bandwidth, the optimized correlation characteristic is maintained due to the cyclic behavior of the self correlation sequences. At the receiver, the retrieved preamble sequence will correspond to a cyclic shift version of the original preamble sequence in the frequency domain. Thus, as long as the pilot density condition continues to be implemented, the basic autocorrelation characteristics continue to apply. Thus, pseudo noise behavior, low PAPR characteristics and optimal autocorrelation characteristics are maintained for any tuning position. Moreover, approximate frequency offset calculations (usually performed in the frequency domain) are still possible.
Figure 33, similar to Figure 6 above, illustrates the repetition of the proposed basic pseudo noise sequence.
33: Structure of Training Symbol with Repetitive Sequences for Each Receive Segment
As mentioned above, repetition of eight training sequences is proposed as a proper compromise between correlation complexity and synchronization reliability. The pn sequence has good overall autocorrelation (i.e. good correlation peak characteristic) as well as proper sliding correlation characteristic (i.e., delivery of CAZAC sequences as used in correlation plateau, ie WLAN preambles). Moreover, synchronization reliability is further improved by reversing the end of the eight training sequences. Training sequences aligned to an 8 MHz raster do not allocate full bandwidth. Within each iteration, multiple carriers are omitted to satisfy spectral characteristics and provide adequate frequency offset compensation. For example, to allow a capture range of 250 kHz, the same bandwidth remains unused on both sides of the training sequence spectrum.
3.7.2. L1 signaling
L1 signaling provides information about all relevant physical layer specific parameters.
As shown in FIG. 32, L1 signaling follows the training sequence phase within each frame. The duration of the L1 signaling is two OFDM symbols. The bandwidth of L1 signaling is 4 MHz, with two L1 blocks (also called signaling patterns) aligned to the initial 8 MHz raster. The frequency behavior of the L1 signaling should reflect the full spectrum mask as well as the typical filter characteristics of the receiver. To allow proper L1 decoding for each arbitrary tuning position, the L1 block does not use all subcarriers within its 4 MHz block. In addition, guard band characteristics from the full channel bandwidth are reused. In any n4k mode, 343 subcarriers on each boundary are not used for data transmission (guard band). The same number of unused carriers is used for L1 signaling, so the number of available carriers per L1 block is 3584 / 2-2 * 343 = 1106 carriers. FIG. 34, similar to FIG. 15 described above, shows carrier allocation of L1 symbols (signaling patterns).
34: Usable frequency ranges of L1 signaling symbols
The structure of the L1 signaling (signaling patterns) below is proposed.
Table 13: L1 Signaling Structure Table 13 indicates that up to 32 different slices are supported in one n4k channel.
n4k n 4 bits n4k current n 4 bits Guard interval length 2 bits Superframe length 16 bit Frame number 16 bit Number of data slices 5 bits Loop through data slices n-segment number 4 bits Start carrier number 12 bit Data slice width (number of carriers) 12 bit Data Slice QAM Modulation 3 bits LDPC block size 1 bit LDPC code rate 3 bits Time interleaver 1 bit Number of notches 2 bits Loop through notches { Start carrier number 12 bit Notch width (number of carriers) 12 bit } End the notch loop PSI / SI reprocessing 1 bit } End data slice loop reservation 1 bit CRC_32 MIP 32 bit
The calculation of the resulting maximum number of L1 signaling bits yields the total number that fits two consecutive (in time domain) QAM modulation L1 symbols with 4 MHz bandwidth, including the overhead of the appropriate FEC scheme.
n of n4k: Defines the overall channel bandwidth of the proposed 4nk symbol as a multiple of 8 MHz.
0001 8 MHz (n = 1)
0010 16 MHz (n = 2)
0011 24 MHz (n = 3)
0100 32 MHz (n = 4)
Current n of n4k: indicates the location of the decoded L1 signaling pattern in the complete 4nk channel.
Guard Interval Length: Defines the length of the guard intervals for all data symbols as well as the L1 symbol.
Superframe Length: This parameter describes the number of frames that make up one superframe.
Frame Number: Allows frame counting within one superframe. At the beginning of each superframe, this counter is reset.
Number of Data Slices: Define the number of frequency slices within the overall channel bandwidth.
n-segment number: This parameter signals the position of the first subcarrier (ie, 8 MHz segment) of the data slice.
Start Carrier Number: Defines the first carrier of the data slice. Numbering is relative to the frame of the associated 8 MHz segment.
Data Slice Width: Defines the number of subcarriers allocated for the data slice.
Data Slice QAM: This parameter indicates the QAM modulation for the data.
Modulation: Segment
LDPC Block Size: Defines the LDPC block size.
LDPC Code Rate: Defines the selected LDPC code rate for the data slice.
110-111 Reserve
Time Interleaver Capable: Signals the use of a time interleaver for this data slice.
Number of Notches: Defines the presence or number of notches in this data slice.
00 no notch in this data slice
01 one notch in this data slice
10 two notches in this data slice
11 3 notches in this data slice
Notch Start: Defines the first carrier of the data slice.
Carrier Number: Numbering is relative to the frame of the associated 8 MHz segment.
Notch Width: Defines the number of subcarriers allocated for the notch.
PSI / SI Reprocessing: Signals whether PSI / SI reprocessing is performed within the headend.
CRC_32 MIP: 32-bit CRC coding for L1 signaling block
3.7.3. Startup procedure
This short chapter is intended to explain preamble processing at the receiving end.
First, the receiver tuner, for example the receive tuner of the receiving device 63 shown in and described in FIG. 18, is tuned to any frequency band that is or is not aligned to the 8 MHz raster in the cable networks. In this position, the tuning window covers one complete preamble sequence and two complete L1 signaling blocks. Thus, the receiver can synchronize, perform initial channel estimation, and extract L1 signaling. From L1 signaling, for example n4k's current n information, the receiver has knowledge about the location of the signaling pattern (s) received and decoded in relation to the current frame, and then the desired data slice (data slice is typically 8 MHz raster). Can be received and decoded at all tuning frames in all subsequent frames of this superframe at this tuning position.
3.8. Data slicing
As described in the previous chapters, the preamble is designed in a manner that allows all important frame related functions (ie receiver synchronization, channel estimation and L1 decoding) at any tuning position. Thus, data slices, ie data patterns as described with respect to FIG. 10, need not follow any fixed segment allocation. An appropriate number of OFDM subcarriers may be allocated. The only condition regarding the width of one data slice is that the width does not exceed the reception bandwidth (ie, 8 MHz-2 * guard band (eg 7.6 MHz)). Each data slice has a certain number of data bits (ie data carriers) per frequency slice per superframe. The number of data bits per data slice can vary from superframe to superframe.
35 shows a configuration as a combination of several OFDM subblocks (data slices) of the entire OFDM signal. Each signal encoding chain is mapped on a matching number of subcarriers.
35: Configuration of the Entire OFDM Signal
The smaller the bandwidth of the data segment, the lower the interleaving gain from the frequency interleaver. The configuration of multiple streams with the same QoS requirements in mode adaptation is one way to deploy frequency diversity in the best possible way.
3.9. Notching
Terrestrial services and DVB cable systems often share the same frequency range. Interferences between both services reduce the SNR of the affected service. Radiation from cable networks disrupts the operation of terrestrial services. Similarly, the transmission quality of cable services is invaded by terrestrial services by causing additional noise on the cable medium. An example is shown in FIG. 36. Notching of OFDM carriers is used to protect different communication systems from each other. OFDM carriers assigned to the same frequency range (s) are excluded from data communication. One example of the above-described system on the terrestrial side is flight security services, and more examples exist.
36: Example of notched C2 OFDM spectrum (red curve) and terrestrial services (eg, flight security service, blue curve) sharing the same frequency range
In order to maximize throughput, the notch width should be as narrow as possible, ie only OFDM subcarriers that directly overlap with terrestrial services should be excluded (see Figure 36).
The location of the notches is part of the L1 signaling. For example, the notched first carrier and notch width are part of the L1 signaling.
3.10. OFDM adaptation to interaction services
If the cable network has return channel capability, the proposed C2 system will be available as a downstream medium for interactive data services as shown in FIG. Similar to existing DVB-C systems, C2 systems will be able to integrate DOCSIS downstream data traffic. Upstream channels are provided in a DOCSIS following manner and are outside the scope of this document.
37: C2 as downstream channel for DOCSIS data
An example of this kind of interactive services is all DOCSIS based data communication including all IP based services or video on demand (VoD).
38: DOCSIS communication in the proposed C2 system
In such a scenario, the proposed system can deploy the benefits of adaptive OFDM (ACM-adaptive coding and modulation). For interactive point-to-point communication services, modems and transmitters can exchange their SNR conditions in their assigned frequency slice to optimize their data throughput. This technique provides precise link data protection as well as dynamic link adaptation to propagation conditions by the targeting of each individual terminal (C2 modem / receiver).
38 shows an exemplary cable network with a C2 headend and a number of connected C2 receivers / modems. Depending on channel effects such as attenuation or multipath fluctuations, the available SNR at each location changes. For example, C2 modem / receiver 1 is very close to the headend, so any attenuation in the downlink spectrum is low. The modem will notify the headend of its good channel conditions, and the headend selects the appropriate combination of modulation and coding with a very high throughput rate. In contrast, the distance between the C2 headend and the C2 modem / receiver 2 is assumed to be very distant and therefore higher attenuation occurs in the reception spectrum. Thus, the available SNR range is much smaller, and C2 modem / receiver 2 notifies the C2 headend to use a more robust combination of modulation and coding.
In theory, it would be possible to signal the SNR condition of each individual OFDM subcarrier back to the C2 headend. Another widely used alternative in other communication systems, such as a power line communication system (PLC), is to transmit one SNR value per interference bandwidth slot. However, this document suggests using only one full combination of modulation and coding for each data slice used for the interaction service. The main reasons are as follows.
L1 signaling / OFDM tonemap complexity: when each subcarrier or interference bandwidth slot is processed separately, not only the L1 signaling data, but also the OFDM tonemap data (ie, feedback data including information including carrier specific SNR conditions). The total amount of will be greatly increased.
Limited SNR fluctuations: Due to the rather low amplitude level of the echo signals, the resulting SNR fluctuations in the relevant frequency slice of the received spectrum are not so large (eg total frequency slot fluctuations of 3 dB or less). Carrier-specific SNR processing is typically targeted by using different modulation schemes for different OFDM subcarriers while the complete data slice is encoded with the same FEC settings (ie LDPC coding). The overall small level of amplitude fluctuations cannot be covered in an efficient manner by rather high SNR steps between different constellations (eg, approximately 6 dB between neighboring square constellations).
If the interactive service data slices select only one global modulation and coding setting, they fit very well into the overall proposed C2 architecture where each different broadcast stream is also allowed to use a particular 'modcod' setting. Despite the additional exchange of SNR conditions between the transmitter and the receiver, the system uses exactly the same data slicing and L1 signaling mechanisms.
Note: Message formats that exchange SNR conditions or signal appropriate combinations of modulation and coding are the subject of a higher layer and are outside the scope of this proposal.
3.11. Spectral shaping
In order to minimize the impact of adjacent channel interference, the DVB-C2 transmission spectrum must implement appropriate spectral mask criteria. Since the proposed C2 system uses n4k OFDM modulation with very high subcarrier QAM constellations, the sidelobe level at the channel boundary is in a physical layer mode requiring the highest SNR value for QEF (pseudo error free) reception in an AWGN environment. Should be less than or equal to the required SNR
39 shows the relationship.
39: OFDM spectral overlap between adjacent channels
In order to improve out-of-band OFDM spectral characteristics and to achieve the required isolation between channels at the boundary frequency between the two channels, filtering is required. Basically, two methods are applicable.
Windowing: Causes amplitude to smoothly go to zero at symbol boundaries (time domain). Windowing in the time domain means that the resulting spectrum is a convolution of the spectrum of the windowing function with a set of impulses at subcarrier frequencies.
Conventional filtering techniques (digital and / or analogue)
Windowing and filtering are two techniques for reducing the out-of-band spectrum. The cutoff behavior of conventional filtering has a potential impact on the performance of high subcarrier modulation modes. In contrast, windowing in the time domain does not cause system degradation. A disadvantage of windowing is the partial overlap between successive symbols and the degradation of the usable guard interval portion associated therewith. 40 shows the basic principle of windowing.
40: Windowing of OFDM symbols in the time domain
The overlap between successive OFDM symbols has a duration T TR . The larger the T TR value, the more the level of the out-of-band spectrum is reduced.
The final channel isolation as well as the associated side lobe attenuation should be considered in the adjacent channel system simulation.
3.12. PAPR
Less complex solutions to PAPR reduction at the transmitter side should be considered. Larger overall FFT sizes due to channel bundling are expected to slightly increase the probable crest factor of the OFDM system. For example, the use of 32K IFFT on the transmitter side is expected to increase the probability crest factor of OFDM systems by less than 0.5 dB compared to 8K FFT based transmitters.
In addition, increasing the QAM modulation order is known to not adversely affect the probability crest factor for OFDM systems with FFT sizes of 1K or greater. Thus, the optimization problem for reducing the crest factor of the proposed OFDM system is similar to that for DVB-T2.
Note that the method of active constellation extension will be less efficient than in DVB-T2 due to the very high order QAM constellations typically used for cable transmissions.
4. System Performance / Throughput
4.1. Throughput rate
The tables below list the different throughput rates of the proposed n4k C2 system for 8 MHz and 32 MHz channel bandwidths. In addition, a comparison is given to the current maximum DVB-C throughput (DVB-C 256 QAM).
The calculation takes into account the following system overhead.
● Guard interval (1/64, 1/128, 1/256)
● BCH codec
● Pilot pattern overhead
Framing overhead (3 of 323 symbols / signaling symbols)
Note: Potential windowing overhead to improve OFDM spectral shaping is not (yet) considered.
4.1.1. 8 MHz channel (n = 1)
4.1.1.1. Guard interval length = 1/64
Table 14: Throughput rate for n = 1 (8 MHz), GI = 1/64
Figure 41: throughput gain of n = 1 (8 MHz), GI = 1/64 (% comparison for DVB-C 256 QAM)
4.1.1.2. Guard interval length = 1/128
Table 15: Throughput rate for n = 1 (8 MHz), GI = 1/128
42: Throughput gain of n = 1 (8 MHz), GI = 1/128 (% comparison for DVB-C 256 QAM)
4.1.1.3 Guard interval length = 1/256
Table 16: Throughput rates for n = 1 (8 MHz), GI = I / 256
4.1.2. 32 MHz channel (n = 4)
4.1.2.1 Guard interval length = 1/64
Table 17: Throughput rate for n = 4 (32 MHz), GI = 1/64
43: Throughput gain of n = 4 (32 MHz), GI = 1/64 (% comparison for DVB-C 256 QAM)
4.1.2.2. Guard interval length = 1/128
Table 18: Throughput gain of n = 4 (32 MHz), GI = 1/128 (% comparison for DVB-C 256 QAM)
Figure 44: Throughput gain of n = 4 (32 MHz), GI = 1/128 (% comparison for DVB-C 256 QAM)
4.1.2.3. Guard interval length = 1/256
Table 19: Throughput gain of n = 4 (32 MHz), GI = 1/256 (% comparison for DVB-C 256 QAM)
4.2. System Performance in AWGN Channels
45 shows the basic performance of different modulation and coding settings in the AWGN channel (target BER = 1E-6). Currently, OFDM inherent overheads (GI, pilots, guard bands, framing) are not included and overall 5.5% (GI = 1 /) for the longest guard interval length of 1/64 and the overall channel bandwidth of 32 MHz. 127% for 128).
45: System Performance (AWGN Channel)
Theoretically, DVB-C 256 QAM requires 29.5dB SNR for QEF operation. According to FIG. 45, 1024 QAM with code rate 9/10 requires approximately the same signal to noise ratio. The spectral efficiency for this mode is 9 bits / Hz. Comparing this with the spectral efficiency (6.875 * 188/204 = 6.34 bits / Hz) of DVB-C 256 QAM, the overall throughput gain of the proposed system is in the range of 42% (which includes the worst 32MHz OFDM inherent overhead). Cases 34.1% respectively).
5. Comparison of proposals with requests (from CM-903)
number General needs System offered One Technologies should aim at optimizing the use of cable channels in modern cable networks. This includes increased flexibility and robustness, as well as maximum payload data capacity. OFDM modulation on subcarriers up to 4k QAM, 32 MHz channel, LDPC codec and many other features 2 DVB-C2 does not primarily aim to match DVB-S2 and / or DVB-T2, but must fully utilize its differentiated features to compete in the content distribution market. Therefore, downstream transmission techniques that benefit most from the availability of return channels should be considered. However, the specification of DVB-C2 should not depend on the availability of the return channel. Adaptive Modulation for Interaction Services 3 In view of the different performance levels of CATV networks, a toolkit of system parameters must be available to address applications ranging from consumer applications to business applications. Various system parameters are provided to optimize network performance. 4 The specification should allow service providers on cable networks to have separate quality of service targets for services in the same multiplex. Partially Satisfied-To limit signaling complexity, service specific protection in one multiplex is not supported. 5 Appropriate technologies that already exist should be adopted whenever possible. Many functional blocks are reused from DVB-S2 and DVB-T2. 6 The expected cable network characteristics (eg, using fiber to curves, buildings, and grooves, as applicable) should be considered appropriately. Use of 4k QAM Modulation for Higher Data Rates in Higher Quality HFC Networks 7 The new technical specifications address only the transmitter functions, but must consider the cost relationship for different devices such as receivers or headend equipment. Design complexity, memory requirements, etc. are considered in the proposal. 8 The DVB-C standard should not be modified, require changes to other specifications (eg, SI), or invalidate any existing features. No modification of existing standards / specifications is required. 9 Specifications should be transmit frequency neutral within typical cable frequency bands. No limit. 10 DVB Family Approach: DVB-C2 should reuse existing solutions for interfacing, coding and modulation where appropriate. DVB-T2 / S2 solutions are reused where possible.
Performance and Efficiency Requirements System offered 11 DVB-C2 must efficiently support the move from mixed analog / digital to all-digital networks and provide maximum performance / throughput on both networks. Peak to average power reduction is used to minimize interference on other channels. 12 DVB-C2 must provide at least 30% more throughput in existing cabling and in-house networks compared to 256 QAM (DVB-C). 1024 QAM or higher modulation scheme. 13 DVB-C2 should allow maximum benefit from the statistical multiplex method. For example, current fixed channel rasters may be deregulated. Flexible channel bandwidth in multiples of 8-32 MHz to 8 MHz. 14 Cable networks should be characterized and modeled at the global (eg US, Asian and European) level (including in-house networks) and the best modulation / FEC schemes should be selected in consideration of realistic cable channel models, including:
Deployment of analog PAL / SECAM / NTSC TV channels
Development of backoff ratios for analog signals of different digital signals (DVB, DOCSIS, Davie, etc.) and related signals
Different noise (white, burst, impulse), nonlinearity and other interferences present in current and future networks The system architecture provides a means to overcome cable specific defects.
Both global frequencies of 8 MHz and 6 MHz can be supported.
Appropriate modulation and coding rates may be selected based on different channel requirements. 15 The error performance of the system should be appropriate for all types of services that can be performed. Different protection levels on the TS or GS level 16 The DVB-C2 transmission system must be able to support low power modes in order to maximize power consumption at the receivers according to the EU Code of Conduct on energy consumption.
Segmented reception reduces complexity. 17 Flawless retransmissions (eg DVB-S2 to DVB-C2, or DVB-T2 to DVB-C2) must be fully supported. Transcoding from DVB-S2 / T2 to C2 is supported. 18 The DVB-C2 standard should provide a sufficiently transparent link to transmission streams, IP packets and other related protocols between the input of the modulator and the output of the demodulator. Flexible mapping of different input formats is supported. 19 The shopping time (time to tune the receiver from one service to another) should not increase significantly due to the introduction of DVB-C2 (with respect to today's user experience of digital TV services using DVB-C). For any change in the RF channel, the DVB-C2 front end must deliver a pseudo error free signal within 300 ms. This is satisfied through optimization of the C2 OFDM frame length.
Backward Compatibility Requirements System offered 20 DVB-C2 must not be backward compatible with DVB-C (in the sense that the DVB-C receiver can process DVB-C2 signals). The ability of the DVB-C2 receiver to incorporate DVB-C functions must be addressed as an optional requirement in the technical specification and thus
If this is a requirement from industry players to include DVB-C functionality in DVB-C2 equipment, chipset manufacturers can provide compliant solutions.
In the long term, even if the networks are completely moved to DVB-C2, these chipsets can be manufactured. The tuner bandwidth in the receiver is maintained at 8 MHz as used in current DVB-C systems. This enables coexistence of DVB-C and DVB-C2 demodulators in the same receiver. 21 For DVB-C2 transmission, there should be no requirement for any changes to existing DVB-C receivers. This assumes the continued use of the same cable network architecture and the same cable channel characteristics. Demand is satisfied 22 To permit self-installation, the DVB-C2 standard should be as insensitive as possible to the typical characteristics of in-house networks using coaxial cable systems.
The proposal supports various coding and interleaving options to reduce non-ideality in in-house cable systems. Interaction System Requirements 22 The specification should be available for consideration as an alternative downstream coding and modulation scheme for DOCSIS systems currently using DVB-C for DOCSIS system's European Technology Option (EuroDOCSIS). The demand is satisfied. 23 DVB-C2 should include techniques for improving the transmission efficiency of IP data. The demand is satisfied. 24 DVB-C2 should allow cost-effective integration into edge QAM solutions for the modulation equipment of DVB-C2. The demand is satisfied. 25 The specification should provide a low latency mode that satisfies the needs of interactive services that require a low latency mode. The time interleaver may be switched off for services that require low latency.
1 is a schematic diagram of an overall transmission bandwidth in which select portions may be selectively and flexibly received by a receiver.
2 is a diagram illustrating an example of division of total transmission bandwidth.
3 is a schematic time domain representation of a frame structure in accordance with the present invention.
4A is a diagram illustrating an example of a frequency domain of a training pattern.
FIG. 4B is a time domain representation of the training pattern of FIG. 4A. FIG.
5A is a frequency domain representation of a further example of a training pattern.
Figure 5 (b) is a time domain representation of the training pattern of Figure 5 (a).
6 is a schematic frequency domain representation of the overall transmission bandwidth with repetitive training patterns in accordance with the present invention.
FIG. 7 is a diagram showing a simulation result of autocorrelation of a multicarrier system in which the transmission bandwidth is the same as the reception bandwidth. FIG.
8 illustrates simulation results of autocorrelation in which the reception bandwidth matches a training pattern, in accordance with the present invention.
9 is a diagram showing a simulation result of autocorrelation when a reception bandwidth does not match a training pattern according to the present invention.
10 shows a schematic example of a frame structure or pattern according to the invention.
FIG. 11 illustrates a part of the frame structure of FIG. 10 with description of reconstruction of the signaling pattern. FIG.
12 shows a schematic example of receiver filter characteristics.
13 shows a further example of a frame structure or pattern according to the present invention.
14 shows a part of a further example of a frame structure or pattern according to the present invention.
15 is a schematic representation of signaling patterns with guard bands.
Fig. 16 is a schematic diagram showing an example of the frame structure of the present invention in the time domain.
17 is a schematic block diagram of an example of a transmission apparatus according to the present invention;
18 is a schematic block diagram of an example of a receiving apparatus according to the present invention;
1: total transmission bandwidth
2: selected part
3: receiving device
4: tuner
5: additional processing means
A transmitting apparatus for transmitting signals in a multicarrier system based on a frame structure,
Frame former configured to form frames of the frame structure, each frame having at least two signaling patterns adjacent to each other in a frequency direction, and a time immediately following the time slot in which the at least two signaling patterns are located Includes at least two data patterns following the at least two signaling patterns in a time direction in a slot;
Each data pattern continuous to the signaling pattern is followed by another data patterns each in a time slot continuous in the time direction,
All data patterns following each other in the time direction have the same frequency direction structure,
Each of the at least two signaling patterns and the data pattern includes a plurality of frequency carriers,
A signaling mapper configured to map signaling data on frequency carriers of each of the at least two signaling patterns in a frame of the frames, each signaling pattern having the same length; and
A data mapper configured to map data on frequency carriers of the at least two data patterns in the frames of the frames;
A transformer configured to transform the signaling patterns and the data patterns from the frequency domain to the time domain to produce a time domain transmission signal,
A transmitter configured to transmit the time domain transmission signal
Transmission device further comprising.
10. The apparatus of claim 1, wherein each frame comprises at least two additional signaling patterns contiguous to the at least two signaling patterns in a time dimension, each of the additional signaling patterns corresponding to one of the at least two preceding signaling patterns. And a transmission device having a length equal to each other.
The pilot mapping according to claim 1 or 2, wherein each frame comprises at least two training patterns, and wherein the transmitting device is configured to map pilot signals on frequency carriers of each training pattern in the frames of the frames. Transmission apparatus comprising means.
4. The apparatus of claim 3, wherein all training patterns have the same length.
The transmitting device according to claim 1 or 2, wherein each signaling pattern of each frame includes a location of each signaling pattern in the frame.
The transmission apparatus according to claim 1 or 2, wherein the signaling patterns of each frame include signaling data indicating the number of data patterns included in the frame.
The apparatus of claim 1 or 2, wherein the structure of signaling data in the signaling patterns supports a limited maximum number of data patterns in the frequency direction of each frame.
The apparatus of claim 1 or 2, wherein the signaling patterns of each frame include separate signaling data for each data pattern included in the frame.
A transmission method for transmitting signals in a multicarrier system based on a frame structure,
Forming frames of the frame structure, each frame having at least two signaling patterns adjacent to each other in a frequency direction, and at least in the time direction in a time slot immediately following the time slot in which the at least two signaling patterns are located; Includes at least two data patterns following the two signaling patterns;
The transmission method includes:
Mapping signaling data on frequency carriers of each of the at least two signaling patterns in the frame, each signaling pattern having the same length;
Mapping data on frequency carriers of the at least two data patterns in the frame;
Converting the signaling patterns and the data patterns from frequency domain to time domain to produce a time domain transmission signal;
Transmitting the time domain transmission signal.
At least two signaling patterns adjacent to each other in a frequency direction, and at least two data patterns following the at least two signaling patterns in a time direction in a time slot immediately following the time slot in which the at least two signaling patterns are located; A multicarrier system configured to use a frame pattern,
Each of the at least two signaling patterns and the data pattern comprises a plurality of frequency carriers,
Signaling data is mapped onto frequency carriers of each of the at least two signaling patterns in a frame, each signaling pattern having the same length,
And data is mapped onto frequency carriers of the at least two data patterns in the frame.
A receiving apparatus for receiving signals based on a frame structure within a transmission bandwidth in a multicarrier system,
Each frame includes at least two signaling patterns, each having signaling data mapped onto frequency carriers, adjacent to each other in a frequency direction, and at least two data patterns having data mapped onto frequency carriers, Each of the at least two signaling patterns has the same length,
Receiving means having at least a length of one of the signaling patterns and configured to receive and tune to a selected portion of the transmission bandwidth, covering at least one data pattern to be received; And
Evaluation means configured to evaluate signaling data included in the received signaling pattern to enable reception of the at least two data patterns
12. The reception device according to claim 11, comprising reconfiguration means configured to reconstruct an original signaling pattern from the received selection portion of the transmission bandwidth.
13. The apparatus of claim 12, wherein the reconstruction means is configured to rearrange received signaling signals into the original signaling pattern when the selected portion of the transmission bandwidth on which the receiving means is tuned does not match the signaling pattern structure. Device.
13. The apparatus of claim 12, wherein each frame comprises at least two additional signaling patterns contiguous to the at least two signaling patterns in a time dimension, each of the additional signaling patterns corresponding to one of the at least two preceding signaling patterns. And each reconstruction means is arranged to rearrange two or more received signaling patterns consecutive to each other in a time dimension into original signaling patterns.
15. The method according to any one of claims 11 to 14, wherein the signaling data of the signaling patterns comprises error correction coding, and wherein the reconstruction means corrects the error on the received signaling signals to reconstruct the original signaling pattern. A receiving device configured to perform decoding.
15. The apparatus according to any one of claims 11 to 14, wherein the signaling patterns of each frame comprise signaling data having the location of each signaling pattern in the frame, and the evaluation means being configured to extract the position information. Device.
15. The method according to any one of claims 11 to 14, wherein the signaling patterns of each frame include signaling data having a number of data patterns included in the frame, and wherein the evaluation means comprises the data pattern from the received signaling pattern. A receiving device configured to extract signaling data having a number of pieces.
15. The method according to any one of claims 11 to 14, wherein the signaling patterns of each frame comprise separate signaling data for each data pattern included in the frame, and the means for evaluating each from the received signaling pattern. A receiving device configured to extract the individual signaling data for a data pattern.
15. The receiver according to any one of claims 11 to 14, wherein the receiving means is tuned to and receives a selected portion of the transmission bandwidth, so that an optimal reception of a signaling pattern in the selected portion of the transmission bandwidth to be received is possible. Device.
15. The apparatus according to any one of claims 11 to 14, wherein the receiving means is configured to tune to and receive a selected portion of the transmission bandwidth, so that the at least one data pattern to be received is selected of the transmission bandwidth to be received. Receiving device centered with respect to the part.
The receiving device according to any one of claims 11 to 14, wherein said receiving means is configured to tune to and receive a selected portion of said transmission bandwidth based on signaling data received in a signaling pattern of a previous frame.
A receiving method for receiving signals transmitted in a multicarrier system based on a frame structure in a transmission bandwidth,
Receiving a selected portion of the transmission bandwidth having at least a length of one of the signaling patterns and covering at least one data pattern to be received; And
Evaluating signaling data included in the received signaling pattern to enable reception of the at least two data patterns
The transmission apparatus according to claim 1 or 2; And
The receiving device according to any one of claims 11 to 14, configured to receive the time domain transmission signal from the transmitting device.
A method for transmitting and receiving signals,
A transmission method for transmitting signals in a multi-carrier system based on the frame structure, each frame comprising at least two signaling patterns adjacent to each other in a frequency direction, and at least two data patterns,
The transmission method
Mapping signaling data on frequency carriers of each of the at least two signaling patterns, each having the same length in a frame;
The method for transmitting and receiving the signals further comprises a receiving method according to claim 22 configured to receive the time domain transmission signal.
KR1020090049231A 2008-06-04 2009-06-03 New frame and signalling pattern structure for multi-carrier systems KR101368506B1 (en)
EP08157548.2A EP2131540B1 (en) 2008-06-04 2008-06-04 New frame structure for multi-carrier systems
EP08157548.2 2008-06-04
EP08157549.0A EP2131519B1 (en) 2008-06-04 2008-06-04 New frame structure for multi-carrier systems
EP08157549.0 2008-06-04
EP08158289.2A EP2131542B1 (en) 2008-06-04 2008-06-13 New frame and signalling pattern structure for multi-carrier systems
EP08158289.2 2008-06-13
EP08158291.8 2008-06-13
EP08158291.8A EP2134044B1 (en) 2008-06-04 2008-06-13 New frame and signalling pattern structure for multi-carrier systems
KR20090127087A KR20090127087A (en) 2009-12-09
KR101368506B1 true KR101368506B1 (en) 2014-03-12
ID=39672319
KR1020090049231A KR101368506B1 (en) 2008-06-04 2009-06-03 New frame and signalling pattern structure for multi-carrier systems
KR20090049038A KR101484790B1 (en) 2008-06-04 2009-06-03 New frame and training pattern structure for multi-carrier systems
US (4) US8121017B2 (en)
EP (3) EP2131540B1 (en)
JP (2) JP5455450B2 (en)
KR (2) KR101368506B1 (en)
CN (3) CN101599795B (en)
AU (2) AU2009201904B8 (en)
ES (2) ES2431337T3 (en)
PL (1) PL2131540T3 (en)
RU (2) RU2498516C2 (en)
TW (3) TWI455536B (en)
EP2523361B1 (en) 2007-12-20 2017-03-22 Sony Corporation Improved transmit power allocation for adaptive multi-carrier multiplexing MIMO systems
ITTO20080472A1 (en) * 2008-06-16 2009-12-17 Rai Radiotelevisione Italiana Spa Method of processing digital signals and transmission and reception system that implements said method
CN102292917B (en) * 2008-10-03 2015-08-26 汤姆逊许可公司 Binary deletion alternate channel is utilized bit interleaver to be adapted to the method and apparatus of LDPC code and modulation under awgn channel condition
CN102187634B (en) * 2008-10-20 2014-01-22 汤姆逊许可公司 Method and apparatus for generating a preamble for use in cable transmission systems
US9065615B2 (en) 2008-10-20 2015-06-23 Samsung Electronics Co., Ltd Preamble transmission and reception method and apparatus for OFDM system
US9264272B2 (en) * 2010-02-11 2016-02-16 Sony Corporation Demapping apparatus and method for reception of data in a multi-carrier broadcast system
WO2011105753A2 (en) * 2010-02-23 2011-09-01 엘지전자 주식회사 Broadcasting signal transmitter/receiver and broadcasting signal transmission/reception method
WO2011105754A2 (en) * 2010-02-23 2011-09-01 엘지전자 주식회사 Broadcasting signal transmitter/receiver and broadcasting signal transmission/reception method
TW201218699A (en) 2010-02-25 2012-05-01 Sony Corp Mapping apparatus and method for transmission of data in a multi-carrier broadcast system
KR101885846B1 (en) * 2010-12-13 2018-08-08 삼성전자주식회사 Method and apparatus for transmitting/receiving data stream in a digital broadcasting system
EP2503723B1 (en) 2011-03-25 2016-04-20 Samsung Electronics Co., Ltd. Method and apparatus for transmitting and receiving control information in a broadcasting/communication system
JP5828215B2 (en) * 2011-03-31 2015-12-02 ソニー株式会社 Receiving device, receiving method, and program
JP5673311B2 (en) 2011-04-06 2015-02-18 ソニー株式会社 Receiving device, receiving method, and program
JP5786421B2 (en) 2011-04-07 2015-09-30 ソニー株式会社 Transmission device, transmission method, reception device, reception method, program, and communication system
JP5862922B2 (en) * 2011-04-07 2016-02-16 ソニー株式会社 Receiving device, receiving method, and program
EP2571191A3 (en) * 2011-09-13 2014-11-26 Samsung Electronics Co., Ltd. Method and apparatus for transmitting/receiving data stream in wireless system
CN104041065B (en) * 2012-10-17 2019-09-03 索尼公司 Data processing equipment, data processing method
WO2014061488A1 (en) * 2012-10-17 2014-04-24 ソニー株式会社 Data processing device, data processing method, and program
MX347490B (en) 2013-01-17 2017-04-28 Lg Electronics Inc Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals.
CA2905028C (en) * 2013-03-11 2017-10-24 Huawei Technologies Co., Ltd. Upstream pilot structure in point to multipoint orthogonal frequency division multiplexing communication system
EP2988510A4 (en) * 2013-04-15 2016-11-16 Lg Electronics Inc Broadcast signal transmitting device, broadcast signal receiving device, broadcast signal transmitting method and broadcast signal receiving method
MX2016002319A (en) * 2013-08-22 2018-04-20 Thomson Licensing Low adjacent channel interference mode for a digital television system.
CN104301009B (en) * 2014-08-22 2017-05-10 国家电网公司 Power line carrier communication method
EP3226571A4 (en) * 2014-11-26 2018-04-18 LG Electronics Inc. Apparatus and method for transmitting and receiving broadcast signal
WO2016108373A1 (en) 2014-12-29 2016-07-07 엘지전자 주식회사 Broadcast signal transmitting device, broadcast signal receiving device, broadcast signal transmitting method, and broadcast signal receiving method
CA2973073A1 (en) 2015-01-05 2016-07-14 Lg Electronics Inc. Broadcast signal transmission apparatus, broadcast signal reception apparatus, broadcast signal transmission method, and broadcast signal reception method
EP3258695A4 (en) 2015-02-13 2018-07-04 LG Electronics Inc. Broadcast signal transmission apparatus, broadcast signal receiving apparatus, broadcast signal transmission method, and broadcast signal receiving method
JP6540295B2 (en) * 2015-07-09 2019-07-10 富士通株式会社 Adaptive equalization circuit, digital coherent receiver and adaptive equalization method
TWI636684B (en) * 2017-03-15 2018-09-21 普誠科技股份有限公司 Signal transceiving device and methods for detecting a synchronization point in a signal
WO2018235396A1 (en) * 2017-06-19 2018-12-27 パナソニック インテレクチュアル プロパティ コーポレーション オブ アメリカ Transmission device, reception device, transmission method, and reception method
WO2007148629A1 (en) 2006-06-20 2007-12-27 Ntt Docomo, Inc. Wireless communication device and wireless communication method used for mobile communication system
EP2262151B1 (en) * 2000-07-05 2017-10-04 Sony Deutschland Gmbh Pilot pattern design for multiple antennas in an OFDM system
KR100492359B1 (en) 2002-09-18 2005-05-31 한기열 Symbol timing detection apparatus of ofdm system
JP4294364B2 (en) * 2003-04-23 2009-07-08 パナソニック株式会社 Multi-carrier communication device
CN1883145B (en) * 2003-11-21 2010-12-08 松下电器产业株式会社 Multi-antenna receiving apparatus, multi-antenna receiving method, multi-antenna transmitting apparatus, and multi-antenna communication system
JP4127818B2 (en) * 2003-12-24 2008-07-30 株式会社東芝 Video coding method and apparatus
US7423968B2 (en) 2004-01-12 2008-09-09 Intel Corporation Systems and methods to convey additional signaling information in a wireless local area network
US20090135802A1 (en) * 2006-01-11 2009-05-28 Matsushita Electric Industrial Co., Ltd. Scalable bandwidth system, radio base station apparatus, synchronous channel transmitting method and transmission method
KR101306733B1 (en) 2006-03-24 2013-09-11 엘지전자 주식회사 A Method and Structure of configuring preamble to support transmission of data symbol in a wireless communication system
CN101155399A (en) * 2006-09-30 2008-04-02 北京三星通信技术研究有限公司;三星电子株式会社 Device and method for control signal transmission in variable band width system
JP4328812B2 (en) * 2006-10-23 2009-09-09 Ｏｋｉセミコンダクタ株式会社 Scattered pilot placement detector
US8139698B2 (en) * 2008-04-11 2012-03-20 Sigma Designs, Inc. Dual correlation frame synchronization system and method
2008-06-04 ES ES08157548T patent/ES2431337T3/en active Active
2008-06-04 EP EP08157548.2A patent/EP2131540B1/en active Active
2008-06-04 PL PL08157548T patent/PL2131540T3/en unknown
2008-06-13 ES ES08158289.2T patent/ES2445644T3/en active Active
2008-06-13 EP EP08158274.4A patent/EP2131541B1/en active Active
2008-06-13 EP EP08158289.2A patent/EP2131542B1/en active Active
2009-05-07 US US12/436,980 patent/US8121017B2/en active Active
2009-05-07 US US12/437,161 patent/US8274878B2/en active Active
2009-05-11 TW TW098115560A patent/TWI455536B/en active
2009-05-12 TW TW098115689A patent/TWI491212B/en active
2009-05-12 TW TW098115692A patent/TWI455537B/en active
2009-05-13 AU AU2009201904A patent/AU2009201904B8/en active Active
2009-05-20 AU AU2009201983A patent/AU2009201983B2/en active Active
2009-06-03 RU RU2009121269/08A patent/RU2498516C2/en active
2009-06-03 JP JP2009134456A patent/JP5455450B2/en active Active
2009-06-03 RU RU2009121265/08A patent/RU2491742C2/en active
2009-06-03 KR KR1020090049231A patent/KR101368506B1/en active IP Right Grant
2009-06-03 JP JP2009134463A patent/JP5561686B2/en active Active
2009-06-03 KR KR20090049038A patent/KR101484790B1/en active IP Right Grant
2009-06-04 CN CN2009101415519A patent/CN101599795B/en active IP Right Grant
2009-06-04 CN CN2009101415449A patent/CN101599973B/en active IP Right Grant
2009-06-04 CN CN200910141553.8A patent/CN101599945B/en active IP Right Grant
2012-02-13 US US13/372,255 patent/US8792322B2/en active Active
2012-05-31 US US13/485,248 patent/US8897120B2/en active Active
US20120213255A1 (en) 2012-08-23
EP2131540B1 (en) 2013-09-18
CN101599945B (en) 2014-01-01
ES2431337T3 (en) 2013-11-26
PL2131540T3 (en) 2013-12-31
US8121017B2 (en) 2012-02-21
TW201008188A (en) 2010-02-16
JP5455450B2 (en) 2014-03-26
CN101599945A (en) 2009-12-09
EP2131542B1 (en) 2014-01-01
JP2009296585A (en) 2009-12-17
JP5561686B2 (en) 2014-07-30
TWI455537B (en) 2014-10-01
EP2131541A1 (en) 2009-12-09
EP2131541B1 (en) 2013-12-18
TWI455536B (en) 2014-10-01
KR20090127081A (en) 2009-12-09
EP2131542A1 (en) 2009-12-09
US8897120B2 (en) 2014-11-25
TW201008187A (en) 2010-02-16
JP2009296586A (en) 2009-12-17
KR20090127087A (en) 2009-12-09
AU2009201904A1 (en) 2009-12-24
US20120236880A1 (en) 2012-09-20
AU2009201904B2 (en) 2014-01-16
AU2009201904B8 (en) 2014-01-30
CN101599973A (en) 2009-12-09
KR101484790B1 (en) 2015-01-20
TW201008189A (en) 2010-02-16
US8792322B2 (en) 2014-07-29
US8274878B2 (en) 2012-09-25
US20090304023A1 (en) 2009-12-10
CN101599973B (en) 2012-08-29
CN101599795A (en) 2009-12-09
AU2009201983A1 (en) 2009-12-24
EP2131540A1 (en) 2009-12-09
CN101599795B (en) 2013-06-12
RU2009121265A (en) 2010-12-10
ES2445644T3 (en) 2014-03-04
US20100034219A1 (en) 2010-02-11
RU2498516C2 (en) 2013-11-10
AU2009201904A8 (en) 2014-01-30
RU2491742C2 (en) 2013-08-27
TWI491212B (en) 2015-07-01
AU2009201983B2 (en) 2014-01-23
RU2009121269A (en) 2010-12-10
US8787141B2 (en) 2014-07-22 Frame and data pattern structure for multi-carrier systems
AU2009307270B2 (en) 2013-08-22 Apparatus for transmitting and receiving a signal and method of transmitting and receiving a signal
CN101599945B (en) 2014-01-01 New frame and signalling pattern structure for multi-carrier systems
US8665691B2 (en) 2014-03-04 Frame and data pattern structure for multi-carrier systems
US20170141942A1 (en) 2017-05-18 Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals
ES2607805T3 (en) 2017-04-04 Apparatus and method for transmitting and receiving a signal
US8958490B2 (en) 2015-02-17 COFDM broadcasting with single-time retransmission of COFDM symbols
AU2009203006B9 (en) 2015-08-20 New frame and signalling pattern structure for multi-carrier systems
JP5500919B2 (en) 2014-05-21 Novel frame and information transfer pattern structure for multi-carrier systems
ES2394669T3 (en) 2013-02-04 Apparatus and method for transmitting and receiving a broadcast signal
US9674021B2 (en) 2017-06-06 Apparatus and method for sending and receiving broadcast signals
2012-07-10 A201 Request for examination
2013-08-12 E902 Notification of reason for refusal