Patent Description:
Therefore, the <NUM> or pre-<NUM> communication system is also called a "Beyond <NUM> Network" or a "Post LTE System". In the <NUM> system, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access(NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

In general, mobile communication systems have been developed to secure mobility of a user and provide communication. The mobile communication system has come to the stage of providing a high-speed data communication service as well as voice communication on the strength of rapid progress of technologies. Recently, a new radio (NR) system is being standardized by <NUM>rd generation partnership project (3GPP) as one of next-generation mobile communication systems. The NR system is developed to satisfy various network requirements and achieve an extensive performance goal, which is a technology for implementing communication in a millimeter wave band. Hereinafter, the NR system may be understood to include a <NUM> LTE system, an LTE-A system, and a <NUM> NR system supporting a microwave as well as communication in a millimeter wave band higher than or equal to <NUM>.

<CIT> concerns synchronization signaling supporting multiple waveforms. <CIT> concerns waveform signaling for downlink communications.

When a BS transmits data to a UE through a single carrier in a millimeter wave (mmWave) higher than or equal to <NUM> in which the NR system can be supported, signal transmission using high power is required to overcome high path loss and signal attenuation. In this case, the BS has difficulty in using a multi-carrier transmission technology, and thus the disclosure proposes a method and an apparatus for effectively transmitting and receiving a synchronization signal and a broadcast signal that carries system information through a single carrier in a millimeter wave band.

According to the disclosure to solve the above-described problem, the BS may acquire a broadcast signal on the basis of a frequency band, subcarrier spacing, a single carrier bandwidth for an SSB, and the size thereof, and identify channel bandwidth information through the acquired broadcast signal on the basis of one or more codepoints of system information. The BS according to an embodiment of the disclosure may transmit a synchronization signal by selectively using different carrier waveforms (CP-OFDM, single carrier (SC) waveform) to transmit system information.

A method by which a BS multiplexes a channel through a single carrier in a downlink includes a step of configuring a signal by selecting a waveform of a synchronization signal from one or more waveforms, a step of configuring information (channel bandwidth) configured by the BS as system information, a step of configuring a broadcast signal to transmit system information and placing the broadcast signal in time and frequency resources, a step of determining a waveform of the broadcast signal on the basis of waveform information of the synchronization signal and generating a signal, and a step of generating a signal of a control channel and data channel resource region on the basis of the system information. A method by which a UE receives an SSB using a single carrier includes a step of reconstructing a synchronization signal through one or more waveforms, a step of reconstructing a broadcast signal on the basis of reconstructed waveform information, a step of identifying system information in the reconstructed broadcast signal, and a step of identifying channel bandwidth information and data reception resource allocation information in the system information.

A BS multiplexing a channel in a millimeter wave wireless communication system according to the disclosure includes a transmitter and a controller configured to control the transmitter. A UE receiving a synchronization signal, a broadcast signal, and a data channel using a single carrier signal in a millimeter wave wireless communication system includes a receiver and a controller configured to control the receiver.

In accordance with an aspect of the disclosure, a method of transmitting a synchronization signal block (SSB) by a BS in a wireless communication system is provided. The method includes: identifying whether a bandwidth of a cell controlled by the BS corresponds to a first frequency band (frequency range (FR)); and when the bandwidth of the cell corresponds to the first frequency band, transmitting the SSB using a single carrier waveform, wherein the SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH) for transmitting system information.

The transmitting of the SSB using the single carrier waveform may include: transmitting the PSS and the SSS using the single carrier waveform in a first bandwidth; and transmitting the system information using the single carrier waveform through the PBCH in a second bandwidth. The transmitting of the SSB using the single carrier waveform may include: transmitting the PSS using a multi-carrier waveform in a first bandwidth; transmitting the SSS using the single carrier waveform in the first bandwidth; and transmitting the system information using the single carrier waveform through the PBCH in a second bandwidth. The transmitting of the SSB using the single carrier waveform may include: transmitting the PSS and the SSS using a multi-carrier waveform in a first bandwidth; and transmitting the system information using the single carrier waveform through the PBCH in a second bandwidth.

The method may further include: transmitting downlink control information (DCI) for scheduling additional system information through a physical downlink control channel (PDCCH) in a frequency band in which the PBCH is not transmitted in a symbol to which the PBCH is mapped; and transmitting additional system information scheduled by the DCI through a physical downlink shared channel (PDSCH) in a frequency band in which the PBCH is not transmitted in another symbol to which the PBCH is mapped.

In accordance with another aspect of the disclosure, a method of receiving a synchronization signal block (SSB) by a UE in a wireless communication system is provided. The method includes: identifying whether a bandwidth of a cell transmitting an SSB which the UE desires to receive corresponds to a first frequency band (frequency range (FR)); when the bandwidth of the cell corresponds to the first frequency band, receiving the SSB using a single carrier waveform; and acquiring synchronization, based on the received SSB and acquiring system information, wherein the SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH) for receiving system information.

In accordance with another aspect of the disclosure, a BS for transmitting a synchronization signal block (SSB) in a wireless communication system is provided. The BS includes: a transceiver; and a controller connected to the transceiver and configured to perform control to identify whether a bandwidth of a cell controlled by the BS corresponds to a first frequency band (frequency range (FR)) and, when the bandwidth of the cell corresponds to the first frequency band, transmit the SSB using a single carrier waveform, wherein the SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH) for transmitting system information.

In accordance with another aspect of the disclosure, a UE for receiving a synchronization signal block (SSB) in a wireless communication system is provided. The UE includes: a transceiver; and a controller connected to the transceiver and configured to perform control to identify whether a bandwidth of a cell transmitting an SSB which the UE desires to receive corresponds to a first frequency band (frequency range (FR)), when the bandwidth of the cell corresponds to the first frequency band, receive the SSB using a single carrier waveform, and acquire synchronization, based on the received SSB and acquire system information, wherein the SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH) for transmitting system information.

According to an embodiment of the disclosure, the BS can efficiently multiplex and transmit a synchronization signal, a broadcast signal, or a control channel and a data channel for data scheduling through a single carrier in a frequency and accordingly increase the coverage. The synchronization signal and the broadcast signal are allocated to and transmitted in different bands, and thus time overhead used for transmitting a synchronization signal block (SSB) can be decreased.

As used herein, the "unit" refers to a software element or a hardware element, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), which performs a predetermined function. However, the "unit" does not always have a meaning limited to software or hardware. The "unit" may be constructed either to be stored in an addressable storage medium or to execute one or more processors. Therefore, the "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, properties, procedures, sub-routines, segments of a program code, drivers, firmware, micro-codes, circuits, data, database, data structures, tables, arrays, and parameters. The elements and functions provided by the "unit" may be either combined into a smaller number of elements, or a "unit", or divided into a larger number of elements, or a "unit". Moreover, the elements and "units" or may be implemented to reproduce one or more CPUs within a device or a security multimedia card. Further, the "unit" in the embodiments may include one or more processors.

In the disclosure below, an uplink (UP) refers to a radio link through which a terminal (user equipment (UE) or mobile station (MS)) transmits data or a control signal to a base station (eNode B, gNB, or BS), and a downlink (DL) refers to a radio link through which the BS transmits data or a control signal to the UE. A <NUM>th generation communication system (or a <NUM> system or a new radio (NR) system) is a communication system after a <NUM>th generation communication system (a <NUM> system, for example, long term evolution (LTE) or evolved universal terrestrial radio access (E-UTRA)), and has been developed to freely reflect various requirements of users and service providers. Services considered for the <NUM> communication system may include enhanced mobile broadband (eMBB) communication aiming at high-speed transmission of high-capacity data, massive machine type communication (mMTC) for minimization of UE power and access of a plurality of UEs, and ultra reliability low latency communication (URLLC) aiming at high reliability and low latency. Different requirements may be applied according to the type of service applied to the UE.

Embodiments of the disclosure are for a communication system in which a BS in an NR system transmits a downlink signal to a UE. An NR downlink signal includes a data channel for transmitting data information, a control channel for transmitting control information, and a reference signal (RS) for channel measurement and channel feedback.

Specifically, an NR BS transmits data and control information to the UE through a physical downlink shared channel (PDSCH) and a physical downlink control channel (PDCCH), respectively. The NR BS may have a plurality of reference signals, and the plurality of reference signals may include one or more of a channel state information RS (CSI-RS) and a demodulation RS or UE-specific RS (DMRS). The NR BS may transmit a UE-specific reference signal (DMRS) only in a region scheduled to transmit data and transmit a CSI-RS in time and frequency axis resources in order to acquire channel information for data transmission. Transmission and reception of a data channel may be understood as transmission and reception of data on the data channel, and transmission and reception of a control channel may be understood as transmission and reception of control information on the control channel.

In the wireless communication system, communication between the BS and the UE is deeply influenced by a propagation environment. Particularly, in a band of <NUM>, attenuation of a signal due to water and oxygen in the atmosphere is very large, and it is difficult to transmit a signal by a small scattering effect due to the length of a small wavelength. Accordingly, the BS can secure coverage only when a signal is transmitted with higher power. When a signal is transmitted using high transmission power, it is difficult to use a multi-carrier transmission technology having the excellent performance to overcome a multi-path delay effect in the <NUM> system because of a high peak to average power ratio (PAPR). However, single-carrier transmission is performed to use higher transmission power, there is a problem in that it is difficult to perform user multiplexing, and channel estimation and channel estimation performance of a multi-path signal deteriorate. In a millimeter wave, an analog beam (hereinafter, interchangeably used with a beam, and understood as a signal having directivity in the disclosure) is used to overcome high pathloss. However, since the length of the wavelength of the millimeter wave is very short, a bandwidth of the analog beam is reduced in which case it is more difficult to support multiple users. As a result, it is difficult to guarantee the performance of a system of the millimeter wave band at a level of a technology used in a microwave band.

Accordingly, the disclosure proposes a method and an apparatus for effectively supporting user multiplexing through a single carrier of a millimeter wave band, and the method and the apparatus are related to a scenario in which the BS operates one single carrier.

<FIG> illustrates the structure of a time-frequency domain that is an NR system resource region.

In <FIG>, the horizontal axis is a time domain, and the vertical axis is a frequency domain. The basic unit of resources in the time and frequency domain is a resource element (RE) <NUM> and may be defined as <NUM> orthogonal frequency division multiplexing (OFDM) symbol <NUM> in the time axis and <NUM> subcarrier <NUM> in the frequency axis. In the frequency domain, <MAT> (for example, <NUM>) successive REs may correspond to one resource block (RB) (or physical resource block (PRB)) <NUM>.

<FIG> illustrates a slot structure considered by the NR system.

In <FIG>, an example of the structure of a frame <NUM>, a subframe <NUM>, and a slot <NUM> is illustrated. One frame <NUM> may be defined as <NUM>. One subframe <NUM> may be defined as <NUM>, and accordingly one frame <NUM> may consist of a total of <NUM> subframes <NUM>. One slot <NUM> or <NUM> may be defined as <NUM> OFDM symbols (that is, the number symbols <MAT> per slot is <NUM>). One subframe <NUM> may include one or a plurality of slots <NUM> and <NUM>, and the number of slot <NUM> or <NUM> per subframe <NUM> may vary depending on a configuration value µ <NUM> or <NUM> for subcarrier spacing. <FIG> illustrates the subcarrier spacing configuration value µ=<NUM><NUM> and µ=<NUM><NUM> by way of example. In the case of µ=<NUM><NUM>, one subframe <NUM> ma include one slot <NUM>. In the case of µ=<NUM><NUM>, one subframe <NUM> may include two slots <NUM>. That is, the number of slots <MAT> per subframe may vary depending on the configuration value µ for subcarrier spacing, and the number of slots <MAT> per frame may vary depending thereon. <MAT> and <MAT> depending on the subcarrier spacing configuration value µ may be defined as [Table <NUM>] below.

<FIG> illustrates a communication system in which the BS and the UE transmit and receive data to and from each other.

Referring to <FIG>, a transmitter is a system capable of performing OFDM transmission and may transmit a single carrier (SC) in a bandwidth in which the OFDM transmission is possible. The transmitter <NUM> may include a plurality of serial-to-parallel (S-P) converters <NUM> and <NUM>, a plurality of single carrier precoders <NUM> and <NUM>, an inverse fast Fourier transform (IFFT) unit <NUM>, a parallel-to-serial (P-S) converter <NUM>, a cyclic prefix (CP) inserter <NUM>, an analog signal unit <NUM> (including a digital-to-analog converter and an RF), and an antenna module <NUM>.

First data <NUM> passing through channel coding and modulation is converted to a parallel signal by the serial-to-parallel converter <NUM>, mapped to the SC precoder <NUM> according to an occupied bandwidth, and converted to a single carrier waveform (SCW) through the SC precoder <NUM>. Also, second data <NUM> passing through channel coding and modulation is converted to a parallel signal by the serial-to-parallel converter <NUM>, mapped to the SC precoder <NUM> according to an occupied bandwidth, and converted to a single carrier waveform (SCW) through the SC precoder <NUM>. At this time, the first data <NUM> and the second data <NUM> may be data transmitted through different channels, data and signals transmitted through channels, different signals, data transmitted in the same channel, or the same signals.

The device <NUM> for converting the parallel signal to the SCW may be implemented through various methods including, for example, a method using a discrete Fourier transform (DFT) precoder, a method using up-converting, and a method using code-spreading. The disclosure may include various precoding methods. Although the specification is described on the basis of an SCW generation method using a DFT precoder for understanding of the disclosure, embodiments of the disclosure may be equally used for the case in which the SCW is generated through another method.

At this time, the size of the DTF <NUM> is M1 and the size of the DFT <NUM> is M2, and a data signal passing through the DFT precoder <NUM> (or a DFT filter) having the length of M1 and a data signal passing through the DFT precoder <NUM> having the length of M2 are converted to broadband frequency signals through an N-point IFFT unit <NUM>. Although the N-point IFFT processor processes transmission of parallel signals through respective subcarriers of channel bandwidths split into N subcarriers, DFT precoding is performed before the N-point IFFT processor in <FIG>, and thus a signal transmitted after IFFT is transmitted using one single-carrier. The N-point IFFT-processed signal (data) is stored as N samples via a process of the parallel-to-serial converter <NUM>, and some of the N stored samples, which are in a back part, are copied and concatenated with a front part. Such a process is performed by the CP inserter <NUM>.

Thereafter, the signal is transmitted to the analog signal unit <NUM> via a pulse shaping filter such as a raised cosine filter and converted to an analog signal via a digital-to-analog conversion process such as a power amplifier (PA), and the converted analog signal is transmitted to the antenna module <NUM> and radiated to the air.

A general SCW signal may be transmitted while M precoded signals are mapped to M successive subcarriers, and such a processor may be performed by the IFFT unit <NUM>. Accordingly, M is determined according to the size of transmitted data or the number of time symbols used by transmitted data. In general, M is much smaller than N, which is because the SCW corresponds to a signal having a small peak-to-average power ratio (PAPR) due to a characteristic thereof.

The PAPR is a degree of a change in transmission power of a sample of the transmitted signal. The large PAPR means that a dynamic range of the PA of the transmitter is large, which means that a power margin required for operating the PA is large. In this case, the transmitter configures a margin of the available PA to be high in case of a great change, and accordingly, maximum power which can be used by the transmitter is reduced. As a result, a maximum communication range between the transmitter and the receiver is reduced. On the other hand, in the case of the SCW having a small PAPR, a change in the PA is very small, and thus the PA can be operated even though the margin is configured to be small. Accordingly, the maximum communication range is increased.

Since propagation attenuation is high in the mmWave wireless communication system, it is important to guarantee a communication range, and thus the BS is advantageous to use a technology of increasing the maximum communication range like the SCW. In general, the SCW has a margin that is <NUM> to <NUM> dB higher than a multi-carrier waveform (MCW), and accordingly, an SCW transmitter uses higher transmission power than the MCW and thus the communication range may increase. The SCW illustrated in <FIG> is used by the UE having the small upper limit of maximum transmission power like the uplink, and particularly, is used for uplink transmission of the LTE system. Particularly, since the upper limit of maximum transmission power is not large, the UE cannot configure the size of M to be large due to lack of uplink transmission power. Further, as transmission power is lower, M is further reduced, and thus a communication range cannot be guaranteed.

Since the BS receives a signal transmitted by one UE in the uplink, there is no need to consider the case in which one or more UEs transmit signals through the same single carrier. On the other hand, in the case of a millimeter wave wireless system, power shortage may be generated in the downlink due to propagation attenuation. In the case of downlink transmission, it is necessary for the BS to simultaneously transmit signals to one or more UEs, so that supporting thereof is required.

Prior to the following description, for frequency regions (FRs) supported by <NUM> NR, a frequency region equal to or lower than <NUM> is referred to as FR1, a frequency region higher than or equal to <NUM> and equal to or lower than <NUM> is referred to as FR3, a frequency region higher than or equal to <NUM> and equal to or lower than <NUM> is referred to FR2, and a frequency region higher than or equal to <NUM> and equal to or lower than <NUM> is referred to as FR4. The disclosure assumes that a first waveform is cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) and a second waveform is a single-carrier waveform. The disclosure can be applied to all single-carrier waveforms, but a DFT spread OFDM (DFT-s-OFDM) waveform is assumed and described for convenience of description. This is because the same description for resource allocation of CP-OFDM can be applied to DFT-s-OFDM.

In the disclosure, a first synchronization signal is a primary synchronization signal (PSS) or a signal corresponding to a function thereof, and a second synchronization signal is a secondary synchronization signal (SSS) or a signal corresponding to a function thereof. A third synchronization signal is a signal having the same function as the first synchronization signal but having different waveform and resource allocation, and a fourth synchronization signal is a signal having the same function as the second synchronization signal but having different waveform and resource allocation. Hereinafter, a DMRS for receiving a PBCH is transmitted temporally earlier than the PBCH. If description is not required, the content of DMRS transmission may be omitted, or a broadcast signal may include both a PBCH channel for initial access system information and a DMRS for reconstructing the same. A control channel (PDCCH) for transmitting downlink control information (DCI) for system information transmission and a data channel (PDSCH) for transmitting system information may be multiplexed with the broadcast signal in a method that is the same as the method of transmitting the broadcast signal (PBCH).

Subsequently, a synchronization signal (SS)/physical broadcast channel (PBCH) block (interchangeably used with a synchronization signal block (SSB)) in the <NUM> system will be described. The SS/PBCH block is a physical layer channel block including a primary SS (PSS), a secondary SS (SSS), and a PBCH. One or more of a plurality of SS/PBCH blocks may be transmitted within a time of <NUM>, and each of the transmitted SS/PBCH blocks may be distinguished by indexes. Specifically, the SS/PBCH block includes the following signals and channels.

PSS: denotes a signal that is a criterion of downlink time and frequency synchronization and provides some information of a cell ID.

SSS: denotes a signal that is a criterion of downlink time and frequency synchronization and provides information on the remaining cell IDs that are not provided by the PSS. Additionally, the SSS may serve as a reference signal for demodulating a PBCH.

PBCH: a master information block (MIB) transmitted through the PBCH provides necessary system information required for transmitting and receiving a data channel and a control channel by the UE (PBCH may be interchangeably used with the broadcast signal). The necessary system information may include search space-related control information indicating radio resource mapping information of a control channel and scheduling control information of a separate data channel for transmitting system information. Specifically, information included in the MIB includes a most significant bit (MSB) of an SS/PBCH block index, a half frame timing indicator, system frame number information, system information block (SIB) <NUM>, subcarrier spacing (SCS) information used for initial access, SSB subcarrier offset information, DMRS location information for a PDSCH, control region (control resource set (CORESET)) configuration information for transmitting DCI scheduling SIB1, and search space configuration information. The control region configured by control region configuration information included in the MIB may be referred to as control region #<NUM>.

The UE may detect the PSS and the SSS in an initial access stage and decode the PBCH. The UE may acquire the MIB from the PBCH and receive a configuration of control region #<NUM> therefrom. The UE monitors control region #<NUM> on the basis of the control region configuration information and the search space configuration information, and receives system information (SIB1) scheduled by downlink control information (DCI) transmitted in control region #<NUM>.

The UE may acquire configuration information related to a random access channel (RACH) required for initial access from the received system information. The UE may transmit a random access (RA) preamble to the BS in consideration of the SS/PBCH index selected by the UE, and the BS receiving the RA preamble may acquire information on the SS/PSBH block index selected by the UE from the BS receiving the RA preamble. Through the process, the BS may know which block was selected from the SS/PBCH blocks by the UE and that the UE monitored control region #<NUM> associated therewith.

<FIG> illustrates a downlink SS and PBCH transmission method to which the disclosure is applied. Referring to <FIG>, an SSB includes an SS and a PBCH <NUM>, and the SS is divided into a PSS <NUM> and an SSS <NUM>. The SSB occupies four symbols <NUM>, and a frequency band occupied by the PSS <NUM> and the SSS <NUM> has the size of <NUM> RBs indicated by reference numeral <NUM>. Actually, <NUM> subcarriers <NUM> are occupied. On the other hand, the PBCH occupies a total of <NUM> RBs indicated by reference numeral <NUM>. In the case of the PSS, there are unoccupied parts on both sides of the <NUM> subcarriers. In the case of the SSS, the PBCH occupies some parts on both sides of the <NUM> subcarriers. Unused power of unoccupied resources may be used for power boosting of the PSS and the SSS. An unused region between the SSS and the PBCH is for a reserved interval to which reception filters of the PSS and the SS are applied. Control region #<NUM> is a control channel region <NUM> (CORESET) for transmitting scheduling information to the UE and is allocated with the size <NUM> of a multiple of <NUM> RBs in advance to a time symbol in which the SSB is transmitted. CORESET allocation information is transmitted through the PBCH. Since the CORESET and the SSB are transmitted through the same symbol, it is assumed that simultaneously transmitted two regions are transmitted using the same beam.

<FIG> illustrates an example in which the BS transmits the SSB. The most noticeable characteristic of the NR SSB is that one BS <NUM> uses one or more beams <NUM> and <NUM>, which is to compensate for radio signal attenuation. If the BS uses L beams, one cell transmits L SSBs in different time symbols as indicated by reference numerals <NUM> and <NUM>, and SSBs transmitted by one BS are transmitted using the same BS ID but different unique SSB IDs (or SS/PBCH block indexes).

<FIG> illustrates a channel multiplexing method according to a first embodiment proposed by the disclosure. According to the first embodiment, the BS may transmit first and second synchronization signals through time and frequency resources different from a broadcast signal, and the size of a single carrier bandwidth of the synchronization signal may be different from the size of a single carrier bandwidth of the broadcast signal. The UE searches for cells of FRs <NUM>, <NUM>, and <NUM>, uses a first waveform to receive a broadcast signal, and receives and reconstructs first and second synchronization signals and the broadcast signal, and searches for a cell of FR4, assumes that a second waveform is used to receive a broadcast signal, and receives and reconstructs first and second synchronization signals and the broadcast signal.

Referring to <FIG>, a first synchronization signal <NUM> and a second synchronization signal <NUM> included in an SSB <NUM> are transmitted in a band <NUM> occupying the PRB size M1, and a bandwidth of the second waveform (that is, a single carrier) is the same as the size of the product of the sequence length of the signals <NUM> and <NUM> and the applied SCS as indicated by reference numeral <NUM>. On the other hand, the broadcast signal includes a reference signal (DMRS) <NUM> for reconstructing the broadcast signal and a broadcast signal transmission symbol <NUM>, and a time symbol and a bandwidth occupied by the signals <NUM> and <NUM> may be different from a time symbol and a bandwidth occupied by the signals <NUM> and <NUM>. The bandwidth occupied by the signals <NUM> and <NUM> has the PRB size M2 <NUM>, and M2 that is the size of the bandwidth of the second waveform for transmitting the signals <NUM> and <NUM> may be configured regardless of M1. At this time, in the time axis, the synchronization signal and the broadcast signal may be transmitted symbol by symbol in an order of the DMRS <NUM>, the PSS <NUM>, and the PBCH <NUM>, and the SSS <NUM>. According to the proposed first embodiment, the BS may transmit the synchronization signal and the broadcast signal in different resources and use power of non-used resources to amplify power at the same time, and secure a low PAPR using the second waveform, thereby increasing all of the coverage of two channels. Since the DMRS is located at the front symbol of the SSB (front-loaded), effective PBCH demodulation may be performed.

<FIG> illustrates a channel multiplexing method according to a second embodiment proposed by the disclosure. According to the second embodiment, the BS transmits first and second synchronization signals in the same symbol as and a different frequency bandwidth from a broadcast signal. The broadcast signal transmitted in the same symbol as the synchronization signal is transmitted using an odd-numbered (or even-numbered) subcarrier in which case the synchronization signal transmitted in the same symbol as the broadcast signal is transmitted using an even-numbered (or odd-numbered) subcarrier. This is to prevent the broadcast signal and the synchronization signal from overlapping each other in the time sample during transmission of a single carrier. The UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use a first waveform to receive the broadcast signal, and receive and reconstruct the first and second synchronization signals and the broadcast signal, and may search for a cell of FR4, assume a second waveform to receive the broadcast signal, and receive and reconstruct the first and second synchronization signals and the broadcast signal.

Referring to <FIG>, a first synchronization signal <NUM> and a second synchronization signal <NUM> included in an SSB <NUM> are transmitted in a band <NUM> occupying the PRB size M1, and a bandwidth M0 <NUM> of the second waveform is the same as the size of the product of double of the sequence length of reference numerals <NUM> and <NUM> and the applied SCS. On the other hand, the broadcast signal includes a reference signal <NUM> for reconstructing the broadcast signal and a broadcast signal transmission symbol <NUM>, and resource allocation <NUM> of the bandwidth occupied by reference numerals <NUM> and <NUM> may be different from resource allocation <NUM> of the bandwidth occupied by reference numerals <NUM> and <NUM>. The size M2 <NUM> of the bandwidth occupied by reference numerals <NUM> and <NUM> may be configured regardless of M0 <NUM>, but it is preferable to configure M2=M0. In the time axis, a DMRS <NUM> and a PSS <NUM> occupy odd-numbered (even-numbered) and even-numbered (odd-numbered) time samples of one symbol corresponding to a first symbol, respectively, a PBCH <NUM> is transmitted in a second symbol, the PBCH <NUM> and the SSS <NUM> occupy odd-numbered (even-numbered) and even-numbered (odd-numbered) time samples of one symbol corresponding to a third symbol, respectively, and the PBCH <NUM> is transmitted in a fourth symbol. According to the second embodiment, the SSB uses four symbols, and thus compatibility with the conventional NR system may be improved. The synchronization signal and the broadcast signal may occupy different bandwidths, and thus reduce a PAPR of the time symbol, thereby improving coverage.

<FIG> illustrates a channel multiplexing method according to a third embodiment proposed by the disclosure. According to the third embodiment, the BS transmits the second synchronization signal in the same symbol as and a different frequency bandwidth from the broadcast signal. The first synchronization signal is transmitted using the first waveform, and the second synchronization signal is transmitted using the second waveform. The BS uses an odd-numbered (or even-numbered) subcarrier for the broadcast signal transmitted in the same symbol as the second synchronization signal, and uses an even-numbered (or odd-numbered) subcarrier for the synchronization signal transmitted in the same symbol as the broadcast signal. The UE searches for cells of FRs, <NUM>, <NUM>, and <NUM>, uses the first waveform to receive the broadcast signal, and receives and reconstructs the first and second synchronization signal and the broadcast signal, and searches for a cell of FR4, assumes the first waveform to receive the broadcast signal, assumes the second waveform to receive and reconstruct the first synchronization signal, and receives and reconstructs the second synchronization signal and the broadcast signal.

Referring to a <NUM> of <FIG>, a first synchronization signal <NUM> and a second synchronization signal <NUM> are transmitted in a band <NUM> occupying the PRB size M1, and a bandwidth M0 <NUM> of the second waveform is the same as the size of the product of the sequence length of a DMRS <NUM> and the applied SCS. The broadcast signal includes a reference signal <NUM> for reconstructing the broadcast signal and a broadcast signal transmission symbol <NUM>. The BS transmits the first synchronization signal <NUM> using the first waveform, transmits the second synchronization signal <NUM> using the second waveform, uses an odd-numbered (or even-numbered) subcarrier to transmit the broadcast signal <NUM> transmitted in the same symbol as the second synchronization signal <NUM> as indicated by reference numeral <NUM>, and uses an even-numbered (or odd-numbered) subcarrier to transmit the second synchronization signal <NUM> transmitted in the same symbol as the broadcast signal <NUM> as indicated by reference numeral <NUM>. The first synchronization signal <NUM> and the second synchronization signal <NUM> may be transmitted in M1 PRBs <NUM> in which case the bandwidth M0 <NUM> of the second wavelength applied to the second synchronization signal <NUM> may be the same as the size <NUM>.

<FIG> illustrates another channel multiplexing method according to a third embodiment proposed by the disclosure. According to the third embodiment, the location of the DMRS for the broadcast signal may vary. In b <NUM>, an example in which the DMRS is transmitted at the location different from that in a <NUM> is illustrated. In b <NUM>, a DMRS <NUM> is located at a first symbol of the SSB, a the second synchronization signal <NUM> and a PBCH <NUM> are multiplexed in a fourth symbol of the SSB unlike in a <NUM>. At this time, as illustrated in a <NUM>, the multiplexed second synchronization signal <NUM> and PBCH <NUM> may be transmitted using crossed subcarrier resources. According to the third embodiment, a second waveform bandwidth <NUM> applied to the DMRS <NUM> and the PBCH <NUM> may be <NUM> RBs. According to the proposed third embodiment, the first synchronization signal is transmitted using the first waveform, and thus the UE may receive the first synchronization signal on the basis of the assumption that the same first synchronization signal is transmitted regardless of a band of a cell for transmitting the SSB. Further, since the first synchronization is transmitted using the first waveform, there is no signal transmitted in the same symbol in spite of a high PAPR, the coverage may be improved due to power amplification. As the second synchronization signal and the broadcast signal occupy different bandwidths, transmission may be performed with a low PAPR of the time symbol and thus the coverage may be improved.

<FIG> illustrates a channel multiplexing method according to a fourth embodiment proposed by the disclosure. According to the fourth embodiment, the BS transmits first and second synchronization signals in a different symbol from and a different frequency bandwidth from a broadcast signal, and transmits the first and second synchronization signals using the first waveform. The first and second synchronization signals may be transmitted using M sequence. The BS transmits third and fourth synchronization signals in the same symbol as or a different frequency band from the broadcast signal, and transmits the third and fourth synchronization signals using the second waveform. The third and fourth synchronization signals may be transmitted using Zadoff-Chu (ZC) sequence.

The BS uses an odd-numbered (or even-numbered) subcarrier to transmit the broadcast signal transmitted in the same symbol as the third and fourth synchronization signals and uses an even-numbered (or odd-numbered) subcarrier to transmit the third and fourth synchronization signal. That is, the BS transmits the broadcast signal and the third and fourth synchronization signals through subcarrier resources that are crossed such that time samples do not overlap each other in a single carrier. The UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use the first waveform to receive the broadcast signal, and reconstruct the first and second synchronization signal and the broadcast signal, and may search for a cell of FR4, assume the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals, and receive and reconstruct the third and fourth synchronization signals and the broadcast signal on the basis of the assumption of the second waveform. The UE may first attempt reception of the first and second synchronization signals in FRs <NUM>, <NUM>, and <NUM>, and may first attempt reception of the third and fourth synchronization signals in FR <NUM>.

Referring to <FIG>, the BS transmits a first synchronization signal <NUM> and a second synchronization signal <NUM> using the first waveform in a first frequency band to transmit an SSB <NUM>, and transmits a third synchronization signal <NUM> and a fourth synchronization signal <NUM> using the second waveform in the same frequency band. A second waveform bandwidth applied to the third synchronization signal <NUM> and the fourth synchronization signal <NUM> may be the same as <NUM> subcarrier spacings as indicated by reference numeral <NUM>. The number of subcarriers occupied by the second waveform may be larger than or equal to the number of subcarriers occupied by the first and second synchronization signals, but should be equal to or smaller than the number <NUM> of PRBs occupied by the first synchronization signal. The third synchronization signal <NUM> and the fourth synchronization signal <NUM> are transmitted in the same symbol as the broadcast signal <NUM>, and resource allocation between the third and fourth synchronization signals <NUM> and <NUM> and the broadcast signal <NUM> does not overlap each other. That is, the third and fourth synchronization signals <NUM> and <NUM> are transmitted using an even-numbered (odd-numbered) subcarrier among subcarriers of the occupied bandwidth, and the broadcast signal <NUM> is transmitted using an odd-numbered (even-numbered) subcarrier. The signal bandwidth <NUM> occupied by the DMRS <NUM> and the broadcast signal <NUM> may have the PRB size M2 (or a second waveform bandwidth <NUM> applied to the DMRS <NUM> and the broadcast signal <NUM> may have the PRB size M2), and M2 should be larger than or equal to the size M1 of the signal bandwidth <NUM> (the number of PRBs) occupied by the synchronization signals <NUM>, <NUM>, <NUM>, and <NUM> and it is preferable that M1=M2.

According to the proposed fourth embodiment, the UE may use the synchronization signals using the first waveform and the second waveform to receive system information or some thereof. That is, since the first synchronization signal and the second synchronization signal of the same resource structure can be transmitted regardless of the frequency band of the cell, the UE (of the cell of FR4) supporting the conventional <NUM> system may detect the first synchronization signal and the second synchronization signal, and the UE supporting the cell of FR4 may or may not detect the first synchronization signal and the second synchronization signal. Further, since another signal is not transmitted in the symbol in which the first and second synchronization signals are transmitted, there is an advantage of guaranteeing the coverage of the first and second synchronization signals through the use of power of corresponding non-used resources to amplify power in spite of the first waveform having a high PAPR and guaranteeing the wide coverage with a low PAPR as the third and fourth synchronization signals and the broadcast signal use the second waveform having different resource configurations.

<FIG> illustrates a channel multiplexing method according to a fifth embodiment proposed by the disclosure. According to the fifth embodiment, the BS may transmit first, second, third, and fourth synchronization signals in the same symbol as and a different frequency bandwidth from a DMRS and a broadcast signal, and at this time, the BS may use an odd-numbered (or even-numbered) subcarrier to transmit the broadcast signal and use an even-numbered (or odd-numbered) subcarrier to transmit the synchronization signal. That is, in the fifth embodiment, the BS may transmit the first and second synchronization signals to overlap each other. The UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals and the broadcast signal, search for a cell of FR4, assume the second waveform to receive the broadcast signal, and receive and reconstruct the first and second synchronizations or receive and reconstruct the third and fourth synchronization signal and the broadcast signal on the basis of the assumption of the second waveform. The UE may first attempt reception of the first and second synchronization signals in FRs <NUM>, <NUM>, and <NUM>, and first attempt reception of the third and fourth synchronization signals in FR4,.

Referring to <FIG>, a first bandwidth occupies M1 PRBs <NUM>, and first, second, third, and fourth synchronization signals <NUM>, <NUM>, <NUM>, and <NUM> are transmitted through the second waveform in an SSB <NUM>. A second waveform bandwidth <NUM> applied to the synchronization signals <NUM>, <NUM>, <NUM>, and <NUM> is included in the M1 PRBs <NUM>. Broadcast signals <NUM> and <NUM> including a DMRS are transmitted in the same symbol as and a different bandwidth from the synchronization signal, and a bandwidth <NUM> occupied by the DMRS and the broadcast signals <NUM> and <NUM> is transmitted to a region of M2 PRBs. At this time, sequences of subcarriers used in the first band <NUM> and subcarriers used in the second band <NUM> do not overlap, and the BS may use odd-numbered subcarriers in the first band and even-numbered subcarrier resources in the second band through, for example, comb. Further, a second waveform bandwidth <NUM> applied to the DMRS <NUM> and the broadcast signal <NUM> may be the same as reference numeral <NUM>. In this case, the symbol transmitted by the BS may maintain a PAPR at the same level as a single carrier waveform.

<FIG> illustrates a channel multiplexing method according to a sixth embodiment proposed by the disclosure. According to the sixth embodiment, the BS transmits a first synchronization signal (including a DMRS) in the same symbol as and a different frequency bandwidth from a broadcast signal, and at this time, the first synchronization signal is transmitted using the first waveform. The BS transmits second, third, and fourth synchronization signals in the same symbol as and a different frequency from the broadcast signal and transmit the same using the second waveform. The BS may use an odd-number (or even-numbered) subcarrier to transmit the broadcast signal transmitted in the same symbol as the second, third, and fourth synchronization signals, and use even-numbered (or odd-numbered) subcarrier to transmit the synchronization signal. The UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals and the broadcast signal, search for a cell of FR4, assume the first waveform to receive the broadcast signal, receive and reconstruct the first synchronization signal, receive and reconstruct the second synchronization signal on the basis of the assumption of the second waveform, and receive and reconstruct the third and forth synchronization signals and the broadcast signal on the basis of the assumption of the second waveform. The UE may first attempt reception of the first and second synchronization signals in FRs <NUM>, <NUM>, and <NUM> and first attempt reception of the third and fourth synchronization signals in FR4.

Referring to <FIG>, the BS transmits a first synchronization signal <NUM> using the first waveform in a first bandwidth <NUM> and transmits second, third, and fourth synchronization signals <NUM>, <NUM>, and <NUM> using the second waveform in the first bandwidth <NUM> in an SSB <NUM>. At this time, the BS transmits broadcast signals <NUM> and <NUM> including a DMRS using the second waveform in a second bandwidth <NUM>. The first bandwidth <NUM> may be the same the size of M1 PRBs, and a second waveform bandwidth <NUM> applied to the second, third, and fourth synchronization signals <NUM>, <NUM>, and <NUM> is included in the first bandwidth <NUM>. The second bandwidth <NUM> may be the same as the size of M2 PRBs, and a second waveform bandwidth <NUM> applied to the broadcast signals <NUM> and <NUM> including the DMRS may be the same as the second bandwidth <NUM>. However, in a symbol in which the first synchronization signal <NUM> using the first waveform is transmitted, no signal is transmitted in the second bandwidth. In a symbol in which a broadcast signal <NUM> overlaps the second, third, and fourth synchronization signals <NUM>, <NUM>, and <NUM>, different subcarrier resources may be used for respective bands. That is, the BS uses an even-numbered (or odd-numbered) subcarrier to transmit a signal transmitted in the first bandwidth <NUM> and uses an odd-numbered (or even-numbered) subcarrier to transmit a signal transmitted in the second bandwidth <NUM>. On the other hand, the broadcast signal <NUM> of a fifth symbol that does not overlap the synchronization signal in the time symbol may be transmitted using all subcarrier resources. A gain of the proposed method is the same as the gain of the fifth embodiment.

<FIG> illustrates a channel multiplexing method according to a seventh embodiment proposed by the disclosure. According to the seventh embodiment, the BS may transmit a broadcast signal in a bandwidth including a transmission bandwidth of first and second synchronization signals, transmit the broadcast signal through a first single carrier band using the second waveform in a symbol in which no synchronization signal is transmitted, and transmit the broadcast signal through a second single carrier band using the second waveform in a symbol in which the synchronization signal is transmitted. The UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals and the broadcast signal, search for a cell of FR4, assume the second waveform to receive the broadcast signal, and receive and reconstruct the first and second synchronization signals and the broadcast signal. Further, the UE may use different second waveform bandwidths (single carrier bandwidths) for respective symbols to receive and reconstruct the broadcast signal of FR4.

Referring to <FIG>, the BS transmits a first synchronization signal <NUM> using the first waveform in a first bandwidth M1 <NUM> in a first symbol of an SSB and transmits a DMRS <NUM> using the second waveform in a bandwidth <NUM> (third bandwidth) having the size of M1+M2 PRBs including M1 in a second symbol. A second synchronization signal <NUM> and a broadcast signal <NUM> are transmitted together using the second waveform in a third symbol. When the broadcast signal <NUM> is transmitted in the same symbol (for example, a third symbol of the SSB) as the second synchronization signal <NUM>, the broadcast signal <NUM> is transmitted in a second band <NUM> corresponding to M2 PRBs, and the second synchronization signal <NUM> and the broadcast signal <NUM> are allocated to different resources in the corresponding symbol. That is, the broadcast signal <NUM> uses odd-numbered (or even-numbered) resources of the subcarrier, and the second synchronization signal <NUM> uses even-numbered (or odd-numbered) resources. In a fourth symbol, the broadcast signal <NUM> is transmitted with the size of M1+M2 using the second waveform. According to the proposed embodiment, the UE may identify a waveform of the second synchronization signal and detect whether the corresponding SSB is based on the first waveform or the second waveform. Further, the UE may determine which information among MIB information used on the basis of the assumption of the first waveform and MIB information used on the basis of the assumption of the second waveform is transmitted by identifying the waveform of the second synchronization signal.

<FIG> illustrates a channel multiplexing method according to an eighth embodiment proposed by the disclosure. According to the proposed eighth embodiment, the BS may transmit a broadcast signal in a wider bandwidth including a transmission bandwidth, in which first and second synchronization signals are transmitted. The first and second synchronization signals may be transmitted using the first waveform and the broadcast signal may be transmitted using the second waveform. The UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals and the broadcast signal, search for a cell of FR4, assume the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals, and receive and reconstruct the broadcast signal on the basis of the assumption of the second waveform.

Referring to <FIG>, a first synchronization signal <NUM> and a second synchronization signal <NUM> are transmitted using the first waveform in a first bandwidth <NUM> having the size of M1 PRBs. A broadcast signal <NUM> including a DMRS is transmitted in a second bandwidth <NUM> having the size of M2 PRBs larger than the first bandwidth having the size of M1 PRBs in a symbol in which the first and second synchronization signals are not transmitted, and the second bandwidth includes the first bandwidth. A second waveform bandwidth <NUM> applied to the broadcast signal <NUM> may be the same as the second bandwidth <NUM>. The first bandwidth <NUM> and the second bandwidth <NUM> may be configured to have the same lowest frequency (or highest frequency) in each bandwidth in a <NUM> of <FIG>, and may be configured to have the same center location as illustrated in b <NUM> of <FIG> illustrates another channel multiplexing method according to the eighth embodiment proposed by the disclosure. In b <NUM>, the configuration of first and second synchronization signals <NUM> and <NUM>, a broadcast signal <NUM>, and a second waveform bandwidth <NUM> except for the location of the bandwidth may refer to the description of a <NUM>. The proposed eighth embodiment includes both a method using the first waveform to transmit the first synchronization signal and the second synchronization signal and using the second waveform to transmit the broadcast signal and a method using the second waveform to transmit all of the first and second synchronization signals and the broadcast signal. Through the proposed method, the UE can distinguish different channels in the time symbol, and there is an advantage of guaranteeing the coverage because no frequency multiplexing is performed.

<FIG> illustrates a channel multiplexing method according to a ninth embodiment proposed by the disclosure. According to the proposed ninth embodiment, the BS transmits first and second synchronization signals using the first waveform in a first bandwidth and transmits a broadcast signal using the second waveform in time resources (symbol) different from the first and second synchronization signals in the first bandwidth. When the bandwidth of the broadcast signal is larger than the bandwidth of the first and second synchronization signals (or when an additional system signal (for example, an SIB) is transmitted through a PDCCH or a PDSCH), a signal of one or more bands is transmitted in the symbol in which the broadcast signal is transmitted, and each band may correspond to a separate single carrier band. When a signal of two bands is transmitted in the symbol in which the broadcast signal is transmitted, an odd-numbered (or even numbered) subcarrier may be used in a first band, and an even-numbered (or odd-numbered) subcarrier may be used in a second band. The UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals and the broadcast signal, search for a cell of FR4, assume the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals, and receive and reconstruct another channel including the broadcast signal on the basis of the assumption of the second waveform.

Referring to <FIG>, in a <NUM>, a first synchronization signal <NUM> and a second synchronization signal <NUM> are transmitted in a first bandwidth <NUM> having the size of N1 PRBs, and at this time, another signal is not transmitted in another band of the corresponding symbol. The first synchronization signal <NUM> and the second synchronization signal <NUM> are transmitted using the first waveform. On the other hand, a broadcast signal <NUM> is transmitted using the second waveform in the first bandwidth <NUM>. The broadcast signal <NUM> may be transmitted to deliver system information for initial access in the first bandwidth <NUM>. When the BS needs to transmit additional system information, the BS may configure control region #<NUM><NUM> for access in the same symbol (for example, a second symbol of the SSB) as the broadcast signal <NUM> and the second bandwidth <NUM> to transmit a PDCCH and transmit additional system information through a PDSCH in the same symbol (for example, a fourth symbol) as the broadcast signal and the second bandwidth <NUM>. The size of the second bandwidth <NUM> has the size of N2, and at this time, the broadcast signal <NUM> is transmitted in the same symbol, and thus the broadcast signal <NUM> should use different resources from those of the PDCCH and the PDSCH. For example, there may be a method of configuring different comb offsets as indicated by reference numerals <NUM> and <NUM>.

<FIG> illustrates another channel multiplexing method according to the ninth embodiment proposed by the disclosure. When an additional DMRS is needed, the DMRS may be added to the SSB in b <NUM>. A DMRS <NUM> may be transmitted in a symbol before the first synchronization signal through a front-loaded scheme, and at this time, the DMRS may be transmitted using the second waveform. For a sequence of the DMRS, all of a method of separately generating sequences of the length N1 and the length of N2 and transmitting the sequences in a first bandwidth <NUM> and a second bandwidth <NUM>, respectively, and a method of generating a sequence of the length of N1+N2 and transmitting the sequence in the first bandwidth <NUM> and the second bandwidth <NUM> can be used.

<FIG> illustrates a channel multiplexing method according to a tenth embodiment proposed by the disclosure. According to the proposed tenth embodiment, the BS may transmit first and second synchronization signals using the first waveform in a first bandwidth and transmit a broadcast signal using the second waveform in different time resources (symbol) from the first and second synchronization signals in a second waveform, and the bandwidth used for transmitting the broadcast signal may be divided into two bandwidths. Specifically, the first bandwidth may be used to transmit initial access system information, and the other bandwidth may be used to transmit an additional system signal through a PDCCH and a PDSCH. When the bandwidth used to transmit the broadcast signal is divided into two bands, the BS may use an odd-numbered (or even-numbered) subcarrier to transmit a signal in the first band, and use an even-numbered (or odd-numbered) subcarrier to transmit a signal in the second band. The UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals and the broadcast signal, search for a cell of FR4, assume the first waveform to receive the broadcast signal, receive and reconstruct the first and second synchronization signals, and receive and reconstruct another channel including the broadcast signal on the basis of the assumption of the second waveform.

Referring to <FIG>, a first synchronization signal <NUM> and a second synchronization signal <NUM> are transmitted in a first bandwidth <NUM> having the size of N1 PRBs, and at this time, another signal is not transmitted in another frequency band of the corresponding symbol. Further, the first synchronization signal <NUM> and the second synchronization signal <NUM> are transmitted through the first waveform. On the other hand, a broadcast signal <NUM> is transmitted using the second waveform in a second bandwidth <NUM> having the size of N2. The broadcast signal is transmitted using a second band to transmit system information for initial access. However, when the BS needs to transmit additional system information, a PDCCH in control region #<NUM><NUM> for access is transmitted using a third bandwidth <NUM> having the size of N3 in the same symbol (for example, a third symbol of the SSB) as the broadcast signal. Further, additional system information may be transmitted through a PDSCH <NUM> in the third bandwidth <NUM> having the size of N3 in the same symbol (for example, a fifth symbol of the SSB) as the broadcast signal. At this time, since the broadcast signal is transmitted in the same symbol as the PDCCH and the PDSCH, it is required to perform transmission using non-overlapping resources. For example, different comb offsets may be configured as indicated by reference numerals <NUM> and <NUM>. When an additional DMRS is required, a DMRS <NUM> may be transmitted in a symbol before the first synchronization signal <NUM> through a front-loaded scheme. At this time, the DMRS is transmitted using the second waveform, and for the sequence of the DMRS, all of a method of separately generating sequences of the length N1 and the length of N2 of the DMRS and transmitting the sequences in a second bandwidth <NUM> and a third bandwidth <NUM>, respectively, and a method of generating a sequence of the length of N2+N3 and transmitting the sequence in the bands can be used.

<FIG> illustrates a channel multiplexing method according to an eleventh embodiment proposed by the disclosure. According to the eleventh embodiment, the UE may search for cells of FRs <NUM>, <NUM>, and <NUM>, use the first waveform to receive a broadcast signal, receive and reconstruct first and second synchronization signals and the broadcast signal, or the UE may search for a cell of FR4, use the second waveform to receive the broadcast signal, receive and reconstruct the broadcast signal, and receive an indication that a channel bandwidth of a cell receiving the broadcast signal as one of operable channel bandwidths through a codepoint of one or more pieces of system information included in the received broadcast signal. In order to search for the cell of FR4, the UE may determine the bandwidth (single carrier bandwidth) used for the second waveform as one of predetermined candidate bandwidths by subcarrier spacing and the number of used subcarriers, and attempts reception of system information through one or more reconstruction attempts.

The method proposed by the eleventh embodiment corresponds to a method of configuring the size of the first bandwidth or the second bandwidth of the synchronization signal using the second waveform according to a channel bandwidth on the basis of a Q-factor and an SSB overhead. The Q-factor is a ratio of an actual data reception filter <NUM> within a channel bandwidth to the channel bandwidth <NUM> for designing an RF filter. If the Q-factor is larger, complexity of the filter design becomes higher, and thus a processing time increases and an area occupied by hardware increases. If subcarrier spacing is wider, a ratio of the first bandwidth occupied by the SSB to the channel bandwidth increases. If the Q-factor is equal to or smaller than <NUM> and the SSB ratio of the bandwidth of the SSB to the channel bandwidth is configured as <NUM>% or lower, the Q-factor according to the channel bandwidth and subcarrier spacing, information on whether the Q-factor is available, and the first bandwidth are as in [Table <NUM>] below.

Since the UE attempts cell access without knowing a channel bandwidth, the UE first receives an SSB on the basis of a predetermined subcarrier spacing candidate according to each band to access the cell of FR4. The UE receives system information after reception of the SSB or additional system information and identifies information on the channel bandwidth in the form of one or more codepoints. A method of indicating information on the channel bandwidth may include a method of indicating an absolute channel bandwidth in the form a codepoint as shown in [Table <NUM>] and a method of predetermining a default bandwidth and indicating an actual bandwidth in the form of a codepoint as shown in [Table <NUM>].

Channel bandwidths shown in [Table <NUM>] and [Table <NUM>] are only examples, and another channel bandwidth in the range shown in [Table <NUM>] may be indicated in the form of a codepoint.

A twelfth embodiment describes a method of configuring a channel raster for searching for an SSB. The channel raster for searching for the SBB may be understood as the center frequency location of the SSB. The conventional channel raster search is configured as shown in [Table <NUM>] below.

The relationship between parameters is described below.

Accordingly, a search for a channel is performed in units of <NUM> in a frequency band higher than or equal to <NUM>. When the search for the channel is performed in units of <NUM>, a signal of another system (for example, point-to-point), which may perform frequency occupancy in a channel higher than or equal to <NUM> in units of <NUM>, cannot be searched for, and multiplexing with the other system in the same band is not possible. In this case, in order to facilitate the search for the channel occupied by the other system (point-to-point) occupying the corresponding band and to guarantee a more rapid channel raster search, the channel raster may be configured as shown in [Table <NUM>] below.

When the channel raster is configured as shown in [Table <NUM>], it is possible to perform a channel search two times faster than the conventional channel search while maintaining multiplexing with another system occupying a band of <NUM>.

When a channel band of <NUM> is configured on the basis of [Table <NUM>], the channel band may be configured through the following method. This is a method of solving the following six problems. A first problem is to configure a frequency division multiplexing (FDD) channel including an uplink band and a downlink band within the band, a second problem is to configure a channel band to be a multiple of <NUM>, a third problem is to also use a time division multiplexing (TDD) channel in a band of <NUM>, a fourth problem is to coexist with the convention point-to-point service, and a fifth problem is to protect an amateur radio signal using a band of <NUM>. A last problem is to make the size of an FDD duplexer (meaning an interval between an uplink band and a downlink band of the FDD channel) larger than or equal to <NUM>. At this time, available bandwidths <NUM>, <NUM>, <IMG>, <NUM> for bands <NUM> to <NUM> may be configured as follows. This method may be equally applied to bands of <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. Further, the method may be applied to an FDD system used only for a band of <NUM> and the case in which bands of <NUM> and <NUM> are used through FDD (at this time, the size of the FDD duplexer is <NUM>).

The proposed method may be applied to a band higher than or equal to <NUM>, in which case the channel raster may be configured as shown in [Table <NUM>] below.

When the proposed method of configuring the channel raster is applied, the UE may receive an SSB in FRs <NUM>, <NUM>, and <NUM> on the basis of CP-OFDM, and preferentially search for an SSB in bands from <NUM> to <NUM> on the basis of CP-OFDM. When the UE fails in receiving the CP-OFDM SSB, the UE may search for the SSB on the basis of DFT-s-OFDM, and search for the SSB on the basis of DFT-s-OFDM in a band higher than or equal to <NUM>. Further, the UE may search for a predetermined SSB in FR4, receive a MIB or a system information block (or system information) on the basis of the SSB, and then identify the type of a waveform used for each channel raster existing in each FR4, included in the system information. Additionally, the system information may include the type of a waveform used for each SSB index (understood as an identifier of the SSB) of the SSB existing in the channel raster in each FR4. When the UE initially receives the SSB on the basis of DFT-s-OFDM or CP-OFDM and then reports UE capability to the BS, the UE may insert the type of a waveform which the UE can receive and the type of a channel (for example, various data channels and control channels such as a PDCCH, a PDSCH, a physical uplink shared channel (PUSCH), and a physical uplink control channel (PUCCH)) or the type a waveform which the UE can receive and transmit for each type of a signal (for example, a DMRS, a CSI-RS, a PSS, or an SSS for the above-described channel) into the capability information and report the UE capability information. When the UE capability is reported to the BS, the UE may insert at least one of the type of the waveform or the channel which the UE can receive for each channel raster range and signal-related information into the capability information and report the capability information. The capability information may further include the type of a waveform which the UE can receive for each of the available frequency bands. For example, the UE may report, to the BS, the UE capability for receiving a downlink channel and/or a signal through CP-OFDM in a bandwidth up to <NUM> and receiving a downlink channel and/or a signal through DFT-s-OFDM in a band higher than or equal to <NUM>.

<FIG> illustrates a channel multiplexing method according to a thirteenth embodiment proposed by the disclosure. The twelfth embodiment is a method of transmitting first and second synchronization signals, a broadcasting channel for transmitting initial access system information, a reference signal, a control channel for transmitting additional system information, and a data channel not to overlap in the time symbol, in which case the signals and the channels are transmitted in a time division multiplexing (TDM) scheme unlike other embodiments in which the signals and the channels are transmitted in a frequency division multiplexing (FDM) scheme. Referring to <FIG>, in a <NUM>, first and second synchronization signals and a broadcast signal for initial access are transmitted in a first bandwidth <NUM>, and an additional broadcast signal is transmitted in a second bandwidth <NUM>. The second bandwidth <NUM> has a center frequency that is the same as the first bandwidth <NUM>, and the size of the second bandwidth <NUM> is larger than that of the first bandwidth <NUM>. The BS transmits the first and second synchronization signals and the broadcast signal for initial access in the first bandwidth <NUM> and the additional broadcast signal in the second bandwidth <NUM> through the second waveform.

<FIG> illustrates another channel multiplexing method according to the thirteenth embodiment proposed by the disclosure. In another method, as illustrated in b <NUM>, the first synchronization signal and the second synchronization signal may be transmitted in a first bandwidth <NUM>, and the broadcast signal for initial access and the broadcast signal for additional system information may be transmitted in a second bandwidth <NUM>. The second bandwidth <NUM> has a center frequency that is the same as the first bandwidth <NUM>, and the size of the second bandwidth <NUM> is large than the size of the first bandwidth <NUM>. Further, a DMRS may be transmitted between the first synchronization signal and the second synchronization signal. The first synchronization signal and the second synchronization signal may be transmitted using the first waveform form or the second waveform, and the remaining channels and signals may be transmitted using the second waveform.

<FIG> illustrates another channel multiplexing method according to the twelfth embodiment proposed by the disclosure. Referring to c <NUM>, the first synchronization signal and the second synchronization signal are transmitted equally to b <NUM>. The broadcast signal for transmitting additional system information is transmitted in a second bandwidth <NUM>. The broadcast signal for initial access may be transmitted while occupying a bandwidth that is the same as the bandwidth (second bandwidth <NUM>) of the broadcast signal for transmitting additional system information in resources (a second symbol in the SSB) occupying the bandwidth that is the same as the first synchronization between the first synchronization signal and the second synchronization signal and in a symbol (a fourth symbol in the SSB) after the second synchronization signal, and the DMRS may be additionally transmitted in the second symbol in which the broadcast signal existing between the first synchronization signal and the second synchronization signal is transmitted. In this case, the DMRS may occupy a third bandwidth <NUM>, the broadcast signal may occupy a first bandwidth <NUM>, and the DMRS and the broadcast signal may occupy subcarrier resources that do not overlap in the time sample in each bandwidth. For example, different comb offsets may be applied to the DMRS and the broadcast signal.

<FIG> illustrates an example of an operation for multiplexing an initial access channel in a millimeter band of the BS according to some embodiments of the disclosure. Referring to <FIG>, the BS determines whether an available bandwidth and a used bandwidth of a cell correspond to a band of FR4 in step <NUM>, and when the bandwidths correspond to the band of FR4, transmits a first synchronization signal (PSS) and a second synchronization signal (SSS) in a first bandwidth using the second waveform in step <NUM>. Thereafter, in step <NUM>, the BS generates system information of the BS for supporting the band of FR4. The generated system information is transmitted in a second bandwidth using the second waveform through a broadcast signal in step <NUM>.

<FIG> illustrates an example of an operation of multiplexing an initial access channel in a millimeter band of the BS according to another embodiment of the disclosure. Referring to <FIG>, the BS determines whether an available bandwidth and a used bandwidth of a cell correspond to a band of FR4 in step <NUM>, and when the bandwidths correspond to the band of FR4, transmits a first synchronization signal (PSS) in a first bandwidth using the first waveform in step <NUM>. The BS transmits a second synchronization signal (SSS) in a first bandwidth using the second waveform in step <NUM>. Thereafter, in step <NUM>, the BS generates system information of the BS for supporting the band of FR4. The generated system information is transmitted in a second bandwidth using the second waveform through a broadcast signal in step <NUM>.

<FIG> illustrates an example of an operation of multiplexing an initial access channel in a millimeter band of the BS according to another embodiment of the disclosure. Referring to <FIG>, the BS determines whether an available bandwidth and a used bandwidth of a cell correspond to a band of FR4 in step <NUM>, and when the bandwidths correspond to the band of FR4, transmits a first synchronization signal (PSS) and a second synchronization signal (SSS) in a first bandwidth using the first waveform in step <NUM>. The BS generates system information of the BS for supporting the band of FR4 in step <NUM>, and the generated system information is transmitted in a first bandwidth or a second bandwidth using the second waveform through the broadcast signal in step <NUM>.

<FIG> illustrates an example of an operation for multiplexing an initial access channel in a millimeter band of the BS according to another embodiment of the disclosure. The BS determines whether an available band and a used band of a cell correspond to a band of FR4 in step <NUM>. When the bandwidths correspond to the band of FR4, the BS transmits a first synchronization signal (PSS) and a second synchronization signal (SSS) in a first bandwidth using the first waveform in step <NUM>, and transmits a third synchronization signal (sPSS) and a fourth synchronization signal (sSSS) using the second waveform in step <NUM>. Thereafter, the BS generates system information of the BS for supporting the band of FR4 in step <NUM>, and the generated system information is transmitted in a first bandwidth or a second bandwidth using the second waveform through the broadcast signal in step <NUM>.

<FIG> illustrates an example of an operation in which the UE receives an initial access channel in a millimeter band of the BS according to an embodiment of the disclosure. Referring to <FIG>, the UE determines whether an available bandwidth and a used bandwidth of a cell correspond to a band of FR4 in step <NUM>, and when the bandwidths correspond to the band of FR4, receives and reconstructs a first synchronization signal (PSS) and a second synchronization signal (SSS) using the predetermined first waveform in a first bandwidth on the basis of the length of a first synchronization signal (or the size of a second waveform bandwidth of the first bandwidth or the size of a first single carrier bandwidth (SC window) when the synchronization signal is transmitted using the second waveform) or/and time symbol allocation information of the synchronization signal in step <NUM>. In step <NUM>, the UE receives and reconstructs the broadcast signal using the predetermined second waveform in a second bandwidth on the basis of the size of a second waveform bandwidth of the second bandwidth of the broadcast signal or the size of a second single carrier bandwidth (SC window) size and/or time symbol allocation information of the broadcast signal. Thereafter, in step <NUM>, the UE acquires channel bandwidth (BW) information using a codepoint of the system information reconstructed in the broadcast signal. In step <NUM>, the UE acquires the size of a third SC bandwidth and/or third resource allocation information for receiving additional system information or a data channel (that may be a frequency of at least one of a PDCCH and a PDSCH and/or time resource allocation information for receiving additional system information or data) of the UE on the basis of the system information reconstructed in the broadcast signal, receives the PDCCH and the PDSCH, and acquires system information or data.

<FIG> illustrates an example of an operation in which the UE receives an initial access channel in a millimeter band of the BS according to an embodiment of the disclosure. Referring to <FIG>, the UE determines whether an available bandwidth and a used bandwidth of a cell correspond to a band of FR4 in step <NUM>, and when the bandwidths correspond to the band of FR4, receives and reconstructs a first synchronization signal (PSS) using the first waveform in a first bandwidth on the basis of time symbol allocation information in step <NUM>. Further, the UE receives and reconstructs a second synchronization signal (SSS) using the predetermined second waveform in the first bandwidth on the basis of the length of the second synchronization signal (the size of a second waveform bandwidth of the first bandwidth or the size of a first single carrier bandwidth (SC window)) or/and time symbol allocation information in step <NUM>. The UE receives and reconstructs a broadcast signal using the predetermined second waveform in a second bandwidth on the basis of the size of a single carrier bandwidth (SC window) of the broadcast signal or/and time symbol allocation information in step <NUM>. Thereafter, in step <NUM>, the UE acquires channel bandwidth (BW) information using a codepoint of the system information reconstructed in the broadcast signal. Further, the UE acquires the size of a third single carrier bandwidth or/and third resource allocation information for receiving additional system information or a data channel (that may be a frequency of at least one of a PDCCH and a PDSCH and/or time resource allocation information for receiving additional system information or data) on the basis of the system information reconstructed in the broadcast signal, receives the PDCCH and the PDSCH, and acquires system information or the data channel.

<FIG> illustrates an example of an operation in which the UE receives an initial access channel in a millimeter band of the BS according to an embodiment of the disclosure. Referring to <FIG>, the UE determines whether an available bandwidth and a used bandwidth of a cell correspond to a band of FR4 in step <NUM>, and when the bandwidths correspond to the band of FR4, receives and reconstructs a first synchronization signal (PSS) and a second synchronization signal (SSS) using the predetermined first waveform in a first bandwidth on the basis of time symbol allocation information in step <NUM>. Step <NUM> may be omitted. The UE receives and reconstructs the first synchronization signal (PSS) and the second synchronization signal (SSS) using the predetermined second waveform in the first bandwidth on the basis of the length of the first synchronization signal (that may be the size of a first single carrier bandwidth or the size of a second waveform bandwidth according to the first bandwidth) and time symbol allocation information in step <NUM>. In step <NUM>, the UE receives and reconstructs a broadcast signal using the predetermined second waveform in a second bandwidth on the basis of the size of a single carrier bandwidth of the broadcast signal (that may be the size of a second waveform bandwidth according to the second bandwidth or a second single carrier bandwidth) or/and time symbol allocation information. Thereafter, in step <NUM>, the UE acquires channel bandwidth (BW) information using a codepoint of the system information reconstructed in the broadcast signal. Further, the UE acquires the size of a third single carrier bandwidth or/and third resource allocation information for receiving additional system information or a data channel (that may be a frequency of at least one of a PDCCH and a PDSCH and/or time resource allocation information for receiving additional system information or data) on the basis of the system information reconstructed in the broadcast signal, receives the PDCCH and the PDSCH, and acquires system information or the data channel in step <NUM>.

<FIG> illustrates an example of an operation in which the UE receives an initial access channel in a millimeter band of the BS according to an embodiment of the disclosure. Referring to <FIG>, the UE determines whether an available bandwidth and a used bandwidth of a cell correspond to a band of FR4 in step <NUM>, and when the bandwidths correspond to the band of FR4, identifies available subcarrier spacing (SCS) in the corresponding frequency band in step <NUM>. Thereafter, the UE acquires the size of a first bandwidth (that may be the same as a first single carrier bandwidth) and the size of a second bandwidth (that may be the same as a second single carrier bandwidth) of the first waveform that can be applied to subcarrier spacing in step <NUM>. Thereafter, the UE receives and reconstructs a first synchronization signal (PSS) and a second synchronization signal (SSS) using the predetermined first waveform in the first bandwidth on the basis of first time symbol allocation information (that may be information on the PSS and the SSS) in step <NUM>. In step <NUM>, the UE receives and reconstructs the broadcast signal using the predetermined second waveform in a second bandwidth on the basis of the size of a single carrier bandwidth of the broadcast signal (corresponding to the size of a second single carrier bandwidth) or/and second time symbol allocation information (that may be information on a DMRS and the broadcast signal). Thereafter, in step <NUM>, the UE acquires channel bandwidth (BW) information using a codepoint of the system information reconstructed in the broadcast signal. Further, in step <NUM>, the UE acquires the size of a third single carrier bandwidth or/and third resource allocation information for receiving additional system information or a data channel (that may be a frequency of at least one of a PDCCH and a PDSCH and/or time resource allocation information for receiving additional system information or data) on the basis of the system information reconstructed in the broadcast signal, receives the PDCCH and the PDSCH, and acquires system information or the data channel.

When the UE fails in reconstructing the broadcast signal or cannot acquire the system information in step <NUM>, the UE attempts again reconstruction of the synchronization signal and the broadcast signal in the corresponding band using the size of another available SCS, another first single carrier bandwidth, or a second single carrier bandwidth.

All steps of the above-described method do not have to be performed, some steps of a plurality of methods may be combined and performed, and orders of the steps may be changed.

<FIG> illustrates a BS apparatus capable of executing embodiments of the disclosure. A BS apparatus <NUM> may include a signal generator/reconstructor <NUM>, a memory, and a controller <NUM>, and a transceiver <NUM> may transmit and receive a signal to and from the UE. The signal may include control information, a reference signal, and data. To this end, the transceiver <NUM> may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal and an RF receiver for low-noise amplifying a received signal and down-converting the frequency. The signal generator/reconstructor <NUM> may reconstruct a signal from a baseband signal received by the transceiver <NUM> or encode a data symbol, output the baseband signal to the controller <NUM>, and transmit the signal output from the controller <NUM> through a radio channel. The signal generation unit may frequency or time-selectively configure baseband signals of the first waveform and the second waveform and transmit the baseband signals to the transceiver. The controller <NUM> may control a series of processes to make the BS operate according to the embodiments of the disclosure.

<FIG> illustrates a UE apparatus capable of performing embodiments of the disclosure. A UE apparatus <NUM> may include a transceiver <NUM>, a memory/controller <NUM>, and a signal generator/reconstructor <NUM>, and the transceiver <NUM> may transmit and receive a signal to and from the BS. The signal may include control information, a reference signal, and data. To this end, the transceiver <NUM> may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal and an RF receiver for low-noise amplifying a received signal and down-converting the frequency. The signal generator/reconstructor <NUM> may reconstruct a baseband signal transmitted from the transceiver <NUM> to predetermined information or data on the basis of the first waveform or the second waveform through control channel information, or attempt the reconstruction on the basis of both the first waveform and the second waveform and, if the reconstruction is successful, identify waveform information of the signal as the assumed waveform. Further, the transceiver may receive a signal through a radio channel, output the signal to the controller <NUM>, and transmit the signal output from the controller <NUM> through a radio channel. The controller <NUM> may control a series of processes to make the UE operate according to the aforementioned embodiments.

Claim 1:
A method performed by a base station, BS, in a wireless communication system, the method comprising:
identifying whether a bandwidth of a cell controlled by the BS corresponds to a first frequency band; and
in case that the bandwidth of the cell corresponds to the first frequency band, transmitting a synchronization signal block, SSB,
wherein the SSB comprises a primary synchronization signal, PSS, a secondary synchronization signal, SSS, and a physical broadcast channel, PBCH, for transmitting system information for an initial access,
wherein the PSS and the SSS are transmitted using a first waveform or a second waveform in a first bandwidth,
wherein in case that the first frequency band is included in a frequency range <NUM>, the PBCH is transmitted using the second waveform in a second bandwidth, and in case that the first frequency band is included in frequency ranges <NUM>, <NUM> or <NUM> having lower starting frequency than the frequency range <NUM>, the PBCH is transmitted using the first waveform in the second bandwidth, and
wherein the first waveform corresponds to a cyclic prefix - orthogonal frequency division multiplexing, CP-OFDM, and the second waveform is a single-carrier waveform.