Scheduling method and device for communication between terminals of communication system

Abstract

The present invention relates to a scheduling technique for communication between terminals of a communication system. Also provided is a method for a first terminal, comprising the steps of: configuring a resource block (RB) set in a unit obtained by adding a guard band to a listen before talk (LBT) bandwidth in a resource pool of a sidelink; configuring a sub-channel including two or more physical resource blocks (PRBs) in a plurality of PRBs included in each RB set; generating sidelink control information, wherein the sidelink control information comprises identification information of at least one scheduled sub-channel in a plurality of sub-channels configured in the RB set; and transmitting the sidelink control information to the second terminal.

Description

Technical Field

[0001] The present disclosure relates to a scheduling technique for communication between terminals in a communication system, and more particularly, to a scheduling technique for communication between terminals in a communication system, which configures transmission resources by considering channel occupancy and occupied bandwidth of an unlicensed band to achieve scheduling. Background Art

[0002] With the development of information and communication technologies, various wireless communication technologies have been developed. Typical wireless communication technologies include Long-Term Evolution (LTE) and New Radio (NR), which are defined in the standards of the 3rd Generation Partnership Project (3GPP). LTE can be one of the fourth-generation (4G) wireless communication technologies, and NR can be one of the fifth-generation (5G) wireless communication technologies.

[0003] To handle the rapidly growing wireless data after the commercialization of fourth-generation (4G) communication systems (e.g., Long-Term Evolution (LTE) communication systems or Long-Term Evolution-Advanced (LTE-A) communication systems), fifth-generation (5G) communication systems (e.g., New Radio (NR) communication systems) using frequency bands higher than those of 4G communication systems (e.g., frequency bands of 6 GHz or higher) as well as frequency bands of 4G communication systems (e.g., frequency bands of 6 GHz or lower) are being considered. 5G communication systems can support enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (URLLC), and massive machine-type communication (mMTC).

[0004] In addition, in a communication system, terminals can transmit or receive data using a sidelink (SL). The sidelink can be configured in an unlicensed band. A terminal can identify the channel occupancy status of radio resources to transmit data via the sidelink of the unlicensed band. In this case, the radio resources that a terminal wants to use may be occupied by another terminal. In this case, the terminal cannot use the radio resources to transmit a signal. Therefore, to smoothly transmit a signal from a terminal, the communication system can configure and schedule transmission resources by considering the channel occupancy and occupied bandwidth of the unlicensed band.

[0005] Matters described as the prior art are prepared to facilitate understanding of the background of the present disclosure, and may include matters unknown to those of ordinary skill in the art to which the exemplary embodiments of the present disclosure belong. Summary of the Invention

[0006]

Technical Problem

[0007] The present disclosure aims to provide a scheduling method and apparatus for communication between terminals in a communication system, which configures transmission resources by considering the channel occupancy and occupied bandwidth of an unlicensed band to achieve scheduling.

[0008]

Technical Solution

[0009] According to a first exemplary embodiment of the present disclosure for achieving the above object, a scheduling method for communication between terminals in a communication system, as a method for a first terminal, may include: configuring a resource block (RB) set from a sidelink resource pool, each RB set corresponding to a unit in which a listen-before-talk (LBT) bandwidth and a guard band are combined; configuring a subchannel including two or more physical resource blocks (PRBs) from among a plurality of PRBs included in each RB set; generating sidelink control information including identification information of at least one scheduled subchannel among the plurality of subchannels configured in the RB set; and transmitting the sidelink control information to a second terminal.

[0010] The method may further include: receiving guard band information from a base station, the guard band information including at least one of information on an index of a PRB of a guard band in the resource pool or information on a number of PRBs of the guard band; and identifying a subchannel including the guard band based on the guard band information.

[0011] The method may further include that the guard band information further includes the number N of PRBs included in the guard band GB of information, when each RB set includes N subch subchannels, configuring the PRBs included in the subchannels with indexes from 0 to (N subch - N GB - 1) for transmission; configuring one PRB in each of the subchannels with indexes from (N subch - N GB ) to (N subch - 1) as a guard band; configuring one PRB in each of the subchannels with indexes from (N subch - N GB ) to (N subch - 1) not to be used for transmission; and calculating a transport block size (TBS) by considering one PRB not used for transmission.

[0012] When the number of PRBs excluded from transmission is equal to or greater than a predetermined number, the number of PRBs excluded from transmission may be considered when calculating the TBS.

[0013] When at least one scheduled subchannel is included in each of at least one RB set, the sidelink control information may further include information on whether to use a guard band for transmission.

[0014] When at least one scheduled subchannel is included in each of at least one RB set, the first terminal may assume that data is punctured and transmitted at the PRBs of the guard band.

[0015] The method may further include: performing a listen-before-talk (LBT) operation before transmitting a signal in a first time slot of at least one scheduling sidelink subchannel; in response to a successful LBT operation, transmitting a signal to a second terminal based on a first transmission time in the first time slot; and in response to a failed LBT operation, transmitting a signal to the second terminal based on a second transmission time in the first time slot, wherein the first transmission time is the time of a symbol index indicated by sidelink start symbol information, and the second transmission time is the time obtained by adding an offset to the time of the symbol index indicated by the sidelink start symbol information.

[0016] The method may further include: receiving information on a plurality of candidate start symbols from a base station; and configuring information on a start symbol dynamically indicated by the base station among the plurality of candidate start symbols as sidelink start symbol information.

[0017] The second transmission time may be at least one of a start time including transmission of an automatic gain control (AGC) symbol, a start time of a physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH), or a start time of an AGC symbol.

[0018] The method may further include determining a transport block size (TBS) by considering at least one of a sidelink symbol length, a number of physical sidelink feedback channel (PSFCH) symbols, a number of demodulation reference signal (DMRS) resource elements (REs), or a number of overhead REs.

[0019] When transmitting a second DMRS at the second transmission time, the first terminal may transmit the second DMRS at a time obtained by adding an offset to a transmission time of a first DMRS to be transmitted at the first transmission time.

[0020] According to a first exemplary embodiment of the present disclosure for achieving the above object, a scheduling apparatus for communication between terminals in a communication system, as a first terminal, may include: a processor, and the processor causes the first terminal to perform: configuring a resource block (RB) set from a sidelink resource pool, each RB set corresponding to a unit in which a listen-before-talk (LBT) bandwidth and a guard band are combined; configuring a subchannel including two or more physical resource blocks (PRBs) from a plurality of PRBs included in each RB set; generating sidelink control information including identification information of at least one scheduling sidelink subchannel among the plurality of subchannels configured in the RB set; and transmitting the sidelink control information to a second terminal.

[0021] The processor may also cause the first terminal to perform: receiving guard band information from a base station, where the guard band information includes at least one of information on the index of physical resource blocks (PRBs) of the guard band in a resource pool or information on the number of PRBs of the guard band; and identifying a sub-channel including the guard band based on the guard band information.

[0022] The guard band information may further include the number N of PRBs included in the guard band, and the processor may also cause the first terminal to perform: when each resource block (RB) set includes N GB sub-channels, configuring the PRBs included in the sub-channels with indexes from 0 to (N subch - N subch - 1) for transmission; configuring one PRB in each of the sub-channels with indexes from (N GB - N subch - N GB ) to (N subch - 1) as a guard band; configuring one PRB in each of the sub-channels with indexes from (N subch - N GB ) to (N subch - 1) not for transmission; and calculating the transport block size (TBS) by considering the one PRB not for transmission.

[0023] The processor may also cause the first terminal to perform: performing a listen-before-talk (LBT) operation before transmitting a signal in a first time slot of at least one scheduled sub-channel; transmitting a signal to a second terminal based on a first transmission time in the first time slot in response to the LBT operation being successful; and transmitting a signal to the second terminal based on a second transmission time in the first time slot in response to the LBT operation failing, where the first transmission time is the time of the symbol index indicated by the sidelink start symbol information, and the second transmission time is the time obtained by adding an offset to the time of the symbol index indicated by the sidelink start symbol information.

[0024] The processor may also cause the first terminal to perform: receiving information on a plurality of candidate start symbols from a base station; and configuring the information on the start symbol dynamically indicated by the base station among the plurality of candidate start symbols as the sidelink start symbol information.

[0025] When continuing to transmit in a second time slot that is the next time slot of the first time slot, the first terminal may transmit a signal in the transmission resource of the guard symbol at a position obtained by adding 1 to the sidelink symbol length.

[0026] The first terminal may notify the second terminal through sidelink control information whether to use the guard symbol at the position obtained by adding 1 to the sidelink symbol length.

[0027]

Technical Effects

[0028] According to the present disclosure, in sidelink communication, a terminal may control and manage transmission time or transmission opportunity by temporarily adding transmission time or transmission opportunity according to the determination result of channel occupancy status. In addition, according to the present disclosure, when configuring frequency-domain resources, the terminal may define bandwidth and subchannel configuration divided by the determined channel occupancy status. In addition, according to the present disclosure, a transmitting terminal and a receiving terminal may use a defined transmission resource structure to use time slots that cannot be used for transmission according to the result of the LBT operation. Description of the Drawings

[0029] Figure 1 is a conceptual diagram showing a first exemplary embodiment of a communication system.

[0030] Figure 2 is a block diagram showing an exemplary embodiment of a communication node constituting a communication system.

[0031] Figure 3 is a conceptual diagram showing a first exemplary embodiment of a system frame in a communication system.

[0032] Figure 4 is a conceptual diagram showing a first exemplary embodiment of a subframe in a communication system.

[0033] Figure 5 is a conceptual diagram showing a first exemplary embodiment of a time slot in a communication system.

[0034] Figure 6 is a conceptual diagram showing a second exemplary embodiment of a time slot in a communication system.

[0035] Figure 7 is a conceptual diagram showing a first exemplary embodiment of time-frequency resources in a communication system.

[0036] Figure 8 is a conceptual diagram showing a first exemplary embodiment of the configuration of a resource pool, an SL signal, and an SL channel within an SL bandwidth part (BWP).

[0037] Figure 9 is a conceptual diagram showing a first exemplary embodiment of SL resources.

[0038] Figure 10 is a conceptual diagram showing a first exemplary embodiment of channel occupancy time in a communication system.

[0039] Figure 11 is a conceptual diagram showing a second exemplary embodiment of channel occupancy time in a communication system.

[0040] Figure 12 is a conceptual diagram showing a first exemplary embodiment of an RB set and subchannels.

[0041] Figure 13 It is a conceptual diagram showing a first exemplary embodiment of the transmission time.

[0042] Figure 14 It is a conceptual diagram showing a first exemplary embodiment of the time domain symbol configuration.

[0043] Figure 15 It is a conceptual diagram showing a second exemplary embodiment of the time domain symbol configuration. Detailed Embodiment

[0044] Since the present disclosure can be modified in various ways and have several forms, specific exemplary embodiments will be shown in the drawings and described in detail in the detailed description. However, it should be understood that it is not intended to limit the present disclosure to these specific exemplary embodiments. On the contrary, the present disclosure is intended to cover all modifications and alternatives falling within the spirit and scope of the present disclosure.

[0045] Relational terms such as first, second, etc. can be used to describe various elements, but the elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, the first component can be named the second component, and the second component can be similarly named the first component without departing from the scope of the present disclosure. The term "and / or" means any one or combination of a plurality of related and described items.

[0046] In an exemplary embodiment of the present disclosure, "at least one of A and B" can mean "at least one of A or B" or "at least one of a combination of one or more of A and B". In addition, "one or more of A and B" can mean "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0047] When it is mentioned that a certain component "is coupled" or "is connected" to another component, it should be understood that the component is directly "coupled" or "connected" to the other component, or other components can be provided therebetween. On the contrary, when it is mentioned that a certain component "is directly coupled" or "is directly connected" to another component, it should be understood that no other components are provided therebetween.

[0048] The terms used in the present disclosure are only used to describe specific exemplary embodiments and are not intended to limit the present disclosure. Unless otherwise clearly specified in the context, singular expressions include plural expressions. In the present disclosure, terms such as "including" or "having" are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but it should be understood that these terms do not exclude the presence or addition of one or more features, numbers, steps, operations, components, parts, or combinations thereof.

[0049] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms that are commonly used and that appear in a dictionary should be interpreted as having a meaning that matches the context of the art. In this specification, terms are not necessarily to be interpreted as having a formal meaning unless explicitly defined.

[0050] Hereinafter, forms of the present disclosure will be described in detail with reference to the drawings. In describing the present disclosure, for the sake of facilitating an overall understanding of the present disclosure, throughout the description of the drawings, the same numerals represent the same elements, and repeated descriptions thereof will be omitted.

[0051] A wireless communication network to which exemplary embodiments of the present disclosure are applied will be described. The wireless communication network to which exemplary embodiments of the present disclosure are applied is not limited to the content described below, and can be applied to various wireless communication networks according to exemplary embodiments of the present disclosure. Here, the wireless communication network can be used in the same sense as a wireless communication system.

[0052] Figure 1 is a conceptual diagram showing a first exemplary embodiment of a communication system.

[0053] Referring to Figure 1 , the communication system 100 may include a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Here, the communication system may be referred to as a "communication network". Each of the plurality of communication nodes may support a communication protocol based on code division multiple access (CDMA), a communication protocol based on wideband CDMA (WCDMA), a communication protocol based on time division multiple access (TDMA), a communication protocol based on frequency division multiple access (FDMA), a communication protocol based on orthogonal frequency division multiplexing (OFDM), a communication protocol based on orthogonal frequency division multiple access (OFDMA), a communication protocol based on single carrier FDMA (SC-FDMA), a communication protocol based on non-orthogonal multiple access (NOMA), or a communication protocol based on space division multiple access (SDMA), etc. Each of the plurality of communication nodes may have the following structure.

[0054] Figure 2 is a block diagram showing an exemplary embodiment of a communication node constituting a communication system.

[0055] Referring to Figure 2, the communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, etc. Each component included in the communication node 200 may communicate with each other as connected by a bus 270. However, each component included in the communication node 200 may be connected to the processor 210 via an interface or a discrete bus instead of the common bus 270. For example, the processor 210 may be connected to at least one of the memory 220, the transceiver 230, the input interface device 240, the output interface device 250, and the storage device 260 through a dedicated interface.

[0056] The processor 210 may execute a program stored in at least one of the memory 220 and the storage device 260. The processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which a method according to an embodiment of the present disclosure is executed. Each of the memory 220 and the storage device 260 may be constituted by at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may include at least one of a read-only memory (ROM) and a random access memory (RAM).

[0057] Referring again to Figure 1 , the communication system 100 may include a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and a plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell, and each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the cell coverage area of the first base station 110-1. Furthermore, the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the cell coverage area of the second base station 110-2. Furthermore, the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the cell coverage area of the third base station 110-3. Furthermore, the first terminal 130-1 may belong to the cell coverage area of the fourth base station 120-1, and the sixth terminal 130-6 may belong to the cell coverage area of the fifth base station 120-2.

[0058] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may refer to a Node-B, evolved Node-B (eNB), base transceiver station (BTS), radio base station, radio transceiver, access point, access node, roadside unit (RSU), digital unit (DU), cloud digital unit (CDU), radio remote head (RRH), radio unit (RU), transmission point (TP), transmission and reception point (TRP), or relay node, etc. Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may refer to a user equipment (UE), terminal, access terminal, mobile terminal, station, user station, mobile station, portable user station, node, or device, etc.

[0059] Each of the multiple communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may support cellular communication (e.g., Long-Term Evolution (LTE) specified in the 3rd Generation Partnership Project (3GPP), or LTE-Advanced (LTE-A), etc.). The multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in the same frequency band or different frequency bands. The multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other via ideal backhaul or non-ideal backhaul and exchange information with each other through ideal backhaul or non-ideal backhaul. Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to the core network via ideal backhaul or non-ideal backhaul. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may transmit the signals received from the core network to the corresponding UE 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6, and transmit the signals received from the corresponding UE 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 to the core network.

[0060] Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can support OFDMA-based downlink transmission and SC-FDMA-based uplink transmission. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can support multiple-input multiple-output (MIMO) transmission (e.g., single-user MIMO (SU-MIMO), multi-user MIMO (MU-MIMO), massive MIMO, etc.), coordinated multi-point (CoMP) transmission, carrier aggregation (CA) transmission, unlicensed band transmission, or device-to-device (D2D) communication (or proximity service (ProSe)), etc. Here, each of the plurality of UEs 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can perform operations corresponding to the operations of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 and the operations supported by the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2.

[0061] A method of operating a communication node in a wireless communication network will be described below. Even if a method (e.g., transmission or reception of a signal) performed at a first communication node in a communication node is described, a corresponding second communication node can perform a method corresponding to the method performed at the first communication node (e.g., reception or transmission of a signal). That is, when the operation of a terminal is described, a corresponding base station can perform an operation corresponding to the operation of the terminal. Conversely, when the operation of a base station is described, a corresponding terminal can perform an operation corresponding to the operation of the base station.

[0062] Figure 3 is a conceptual diagram showing a first exemplary embodiment of a system frame in a communication system.

[0063] Referring to Figure 3 , the time resources in a communication system can be divided based on frames. For example, the system frame of a communication system can be configured continuously in the time domain. The length of the system frame can be 10 milliseconds (ms). The system frame number (SFN) can be set to one of #0 to #1023. In this case, 1024 system frames can be repeated in the time domain of the communication system. For example, the SFN of the system frame after system frame #1023 can be #0.

[0064] One system frame can include two half-frames. The length of one half-frame can be 5 ms. The half-frame located in the starting area of the system frame can be called "half-frame #0", and the half-frame located in the ending area of the system frame can be called "half-frame #1". One system frame can include 10 sub-frames. The length of one sub-frame can be 1 ms. The 10 sub-frames within one system frame can be called sub-frames #0 to #9.

[0065] Figure 4 It is a conceptual diagram showing a first exemplary embodiment of a subframe in a communication system.

[0066] Referring to Figure 4 , a subframe may include n time slots, and n may be a natural number. Therefore, a subframe may be composed of one or more time slots.

[0067] Figure 5 It is a conceptual diagram showing a first exemplary embodiment of a time slot in a communication system.

[0068] Referring to Figure 5 , a time slot may include one or more symbols. For example, a time slot may include 14 symbols.

[0069] Figure 6 It is a conceptual diagram showing a second exemplary embodiment of a time slot in a communication system.

[0070] Referring to Figure 6 , a time slot may include one or more symbols. For example, a time slot may include 7 symbols.

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[0072] and <000Symbols can be configured as downlink (DL) symbols, flexible (FL) symbols, or uplink (UL) symbols. A time slot consisting only of DL symbols can be referred to as a "DL time slot", a time slot consisting only of FL symbols can be referred to as an 'FL time slot', and a time slot consisting only of UL symbols can be referred to as a "UL time slot".

[0074] Figure 7 is a conceptual diagram showing a first exemplary embodiment of time-frequency resources in a communication system.

[0075] Referring to Figure 7 , a resource composed of one OFDM symbol on the time axis and one subcarrier on the frequency axis can be defined as a "resource element (RE)". A resource composed of one OFDM symbol on the time axis and K subcarriers on the frequency axis can be defined as a "resource element group (REG)". A REG can include K REs. A REG can be used as a basic unit for resource allocation in the frequency domain. K can be a natural number. For example, K can be 12. N can be a natural number. In Figure 5 the shown time slot, N can be 14. N OFDM symbols can be used as a basic unit for resource allocation in the time domain.

[0076] A method of transmitting and receiving data in a communication network will be described below. In downlink communication, downlink data can be transmitted through the PDSCH. In uplink communication, uplink data can be transmitted through the PUSCH. In the present disclosure, the PDSCH can refer to downlink data or a resource for transmitting and receiving downlink data, and the PUSCH can refer to uplink data or a resource for transmitting and receiving uplink data. A base station can transmit downlink control information (DCI) including configuration information of the PDSCH (e.g., resource allocation information, scheduling information) through a physical downlink control channel (PDCCH). In the present disclosure, the PDCCH can refer to DCI (e.g., control information) or a resource for transmitting DCI.

[0077] A terminal can receive DCI on the PDCCH and identify the configuration information of the PDSCH included in the DCI. For example, the configuration information of the PDSCH can include time domain resource allocation (TDRA), frequency domain resource allocation (FDRA), and / or modulation and coding scheme (MCS) information. The TDRA can indicate the resource region of the PDSCH in the time domain. The FDRA can indicate the resource region of the PDSCH in the frequency domain. The MCS information can indicate the MCS level or MCS index.

[0078] A sidelink (SL) communication method in a communication network will be described. SL communication can be performed in an authorized frequency band and / or an unauthorized frequency band. SL communication in the unauthorized frequency band can be referred to as sidelink unauthorized (SL-U) communication or unauthorized sidelink (U-SL) communication. SL resources can be used for the transmission of SL signals and / or channels. SL resources can be configured based on a resource pool. The resource pool can be referred to as an SL resource pool. The resource pool can include a Tx resource pool and / or an Rx resource pool. The Tx resource pool can be used for SL transmission, and the Rx resource pool can be used for SL reception. The Tx resource pool and the Rx resource pool can be distinguished from each other. The Tx resource pool and the Rx resource pool can be configured independently.

[0079] In the time domain, the resource pool can include one or more time slots, and in the frequency domain, the resource pool can include one or more subchannels. One subchannel can include N PRB physical resource blocks (PRBs). N PRB can be one of 10, 12, 15, 20, 25, 50, 75, or 100. The resource pool can be configured periodically. For example, the resource pool can be configured with a period of 10240 milliseconds (ms) in the time domain. Some of the time slots in all the time slots belonging to the period corresponding to the 10240 ms periodicity can be configured as the resource pool. According to the time division duplex (TDD) configuration, the time slots including downlink (DL) symbols can not be configured as the resource pool. The time slots including the resources for transmitting sidelink synchronization signal blocks (S-SSBs) can not be configured as the resource pool. The time slots that can be configured as the resource pool can be defined by a bitmap. In other words, the bitmap can indicate the time slots that can be configured as the resource pool.

[0080] In addition, the sidelink (SL) channel can be as follows. In other words, the sidelink channel can deliver traffic, data, etc. related to the sidelink service. Alternatively, the sidelink channel can deliver control information related to sidelink management and scheduling.

[0081] The SL channel can be used for transmitting and receiving traffic (e.g., data), management information, and / or control information (e.g., control information related to scheduling) related to the SL service. The SL channel can include a physical sidelink broadcast channel (PSBCH), a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), and / or a physical sidelink feedback channel (PSFCH). The SL signal can include a synchronization signal (e.g., sidelink primary synchronization signal (S-PSS), sidelink secondary synchronization signal (S-SSS)) and / or a reference signal (e.g., demodulation reference signal (DMRS), channel state information reference signal (CSI-RS), phase tracking (PT)-RS, and positioning reference signal (PRS)).

[0082] The PSSCH can be a channel for transmitting and receiving transport blocks (TBs), data, and / or traffic. The PSCCH can be a channel for transmitting and receiving control information. The PSFCH can be a channel for transmitting and receiving hybrid automatic repeat request (HARQ) feedback indicating the reception status of the PSSCH. The sidelink synchronization signal block (S-SSB) can include at least one of the PSBCH, S-PSS, or S-SSS. The S-SSB can also include DMRS. Synchronization between terminals can be performed using synchronization signals (e.g., S-PSS and / or S-SSS).

[0083] Figure 8 is a conceptual diagram of a first exemplary embodiment showing the configuration of a resource pool, sidelink (SL) signals, and SL channels within an SL bandwidth part (BWP).

[0084] Referring to Figure 8 , the resource pool can include one or more time slots, but excludes time slots that do not meet the resource pool configuration conditions and / or time slots not indicated by a bitmap among the multiple time slots. Discontinuous time slots in the time domain can be interpreted as continuous time slots within the resource pool. In other words, even if the time slots configured as the resource pool are discontinuous, the indices of the time slots within the resource pool can be continuous.

[0085] In the present disclosure, an SL resource (e.g., an SL transmission resource) can refer to a resource within the resource pool. An SL resource can refer to a resource for transmitting an SL signal and / or an SL channel. In the present disclosure, signal transmission can refer to the transmission of an SL signal and / or an SL channel, and signal reception can refer to the reception of an SL signal and / or an SL channel. A "signal" can be interpreted as "signal" or "signal + channel", while a "channel" can be interpreted as "channel" or "channel + signal". An "SL signal / channel" can be interpreted as "SL signal", "SL channel", or "SL signal + SL channel".

[0086] Figure 9 is a conceptual diagram of a first exemplary embodiment showing an SL resource.

[0087] Referring to Figure 9, the basic transmission unit of the SL signal / channel in the time domain can be a time slot, and the basic transmission unit of the SL signal / channel in the frequency domain can be a sub-channel. The transmission resources of the SL signal / channel can include one or more time slots and / or one or more sub-channels. The transmission resources can include PSCCH and / or PSSCH. In addition, the transmission resources can include PSFCH. The time slot including PSFCH (e.g., time slot position) can be predefined. The time slot including PSFCH can be referred to as a PSFCH time slot. The configuration conditions of the PSFCH time slot in the authorized band can be different from those of the PSFCH time slot in the unauthorized band. The transmission operation of HARQ feedback in the PSFCH time slot in the authorized band can be different from that in the PSFCH time slot in the unauthorized band. The configuration information of the SL channel actually transmitted in the transmission resources can be transmitted by signaling (e.g., RRC message, SCI). The configuration information of the SL channel can include frequency resource information (e.g., the position of the frequency resource area), time resource information (e.g., the position of the time resource area), etc.

[0088] In an exemplary embodiment, the OFDM symbols available for signal transmission within the time slot of the basic transmission unit can be defined according to the SL start symbol (e.g., sl-StartSymbol) and the SL symbol length (e.g., sl-LengthSymbols). Here, when configuring the sidelink in the unauthorized band, a sub-time slot with a time length less than the time slot length or OFDMA symbols of any length can be used as the OFDM symbols for signal transmission. In an exemplary embodiment, the OFDM symbols available for signal transmission within the time slot of the basic transmission unit can be defined according to the RRC message including sl-LengthSymbols. Alternatively, in another exemplary embodiment, the relevant information can be included in the SCI.

[0089] In the case of a sidelink sub-channel, one sub-channel can be configured with N PRB4subchannel consecutive PRBs. Here, N PRB4subchannel can be defined by the RRC message or the base station. Each sub-channel can be continuously configured within the resource pool. When configuring the sidelink in the unauthorized band, the sub-channel can be configured as a set of physically distributed PRBs. For example, the sub-channel can be configured with N PRB4subchannel consecutive PRBs at regular PRB intervals. In the present disclosure, the structure of the sub-channel configured as a set of regularly spaced PRBs can be defined as an "interleaved sub-channel".

[0090] The base station can transmit the configuration information of the SL channel (e.g., transmission resource information) to the terminal. The terminal can receive the configuration information of the SL channel from the base station and transmit the SL channel based on the configuration information (e.g., the transmission resources indicated by the configuration information). Alternatively, the terminal can select resources by performing a resource sensing operation and / or a resource selection operation, and can transmit the SL channel on the selected resources. The selected resources can mean transmission resources. The transmission resources can include one or more subchannels and one or more time slots.

[0091] The transmitting terminal can transmit an SCI including the transmission resource information (e.g., scheduling information) of the PSSCH to the receiving terminal. The transmission resource information can be the allocation information of the subchannel and / or time slot of the PSSCH. The transmitting terminal can refer to the terminal that transmits the PSSCH (e.g., data). The receiving terminal can refer to the terminal that receives the PSSCH (e.g., data). The transmission resource information included in the SCI can indicate the transmission resources of the PSSCH in the time slot when the SCI is transmitted. Alternatively, the transmission resource information included in the SCI can indicate the transmission resources of the PSSCH in a time slot other than the time slot when the SCI is transmitted.

[0092] In SL-U communication, a listen-before-talk (LBT) operation can be performed to coexist with other communication nodes (e.g., communication devices). The actual transmission resources can be determined based on the result of the LBT operation. The terminal can perform the LBT operation, and if the LBT operation is successful, the terminal can use the channel within a specific time (e.g., channel occupancy time (COT)). For example, if the LBT operation of the terminal is successful, the terminal can initiate the COT, and the terminal can perform communication (e.g., SL-U communication) during the COT. According to specific conditions, other terminals (e.g., terminals that have not initiated the COT) can perform communication (e.g., SL-U communication) during the COT. In other words, the COT can be shared with other terminals, and in this case, other terminals can perform communication within the shared COT.

[0093] The transmission unit (e.g., symbol configuration) within the COT can vary. The configuration information of the transmission unit within the COT can be transmitted by signaling (e.g., SCI). The symbol can refer to an OFDM symbol. In Figure 9 an exemplary embodiment, the PSCCH and the PSSCH can be configured together within the transmission resources. The PSCCH can be configured starting from the PRB with the lowest index among the subchannels with the lowest index configured for PSSCH transmission.

[0094] The number of OFDM symbols for PSCCH configuration can be 2 or 3. In this case, the starting position of the OFDM symbols for PSCCH configuration can be defined as index [SL-start symbol (e.g., sl-StartSymbol)+1].

[0095] Operations, procedures, control information, and / or configuration information regarding the occupation of working channels in SL-U communication will be described. A working channel may refer to a frequency resource with a bandwidth of a predefined size. Resources in the unlicensed band (e.g., time resources, frequency resources, carriers, subcarriers, sub-channels) may be occupied by communication nodes belonging to a network other than a cellular network (e.g., a 4G network, a 5G network), such as a wireless local area network (WLAN). Resources in the unlicensed band may be occupied by signals / channels transmitted and received between a base station and a terminal belonging to a cellular network. Resources in the unlicensed band may be occupied by signals / channels transmitted and received between terminals belonging to a cellular network.

[0096] In this disclosure, a communication node (e.g., a base station, a terminal) transmitting a signal / channel may be represented as a transmitting node, and a communication node (e.g., a base station, a terminal) receiving a signal / channel may be represented as a receiving node. In the unlicensed band, communication nodes may share a working channel. An LBT operation may be performed to minimize interference between communication nodes. The LBT operation may include an operation of checking whether a working channel is occupied by another signal before transmitting a signal / channel. If the LBT operation is supported, a communication node (e.g., a transmitting node) may perform a random backoff process.

[0097] If the LBT operation is successful, a communication node may occupy the working channel. The occupation of the working channel may be referred to as channel occupation (CO). A terminal may ensure CO by performing the LBT operation. The configuration of CO may vary according to the type of LBT operation performed by the terminal. For example, the maximum length of CO may vary according to the type of LBT operation performed by the terminal. The type of LBT operation performed by the terminal may vary according to the priority class of the data that the terminal wishes to transmit within CO.

[0098] A terminal may perform the LBT operation using different parameters (e.g., different LBT parameters) to obtain a CO corresponding to each priority class. When performing the LBT operation according to the priority class, the parameters determining the LBT operation execution time may vary. In the LBT operation involving a random backoff process, the minimum and / or maximum size of the contention window (CW) may be set differently for each priority class. A terminal may select a random backoff counter within the CW and perform a random backoff process based on the selected random backoff counter.

[0099] A fixed time period for performing the LBT operation may be determined based on the type of LBT operation and / or LBT parameters. The length of the fixed time period may be 16 μs or 25 μs.

[0100] In the present disclosure, the LBT process that requires a random backoff process may be represented as "LBT type A". In addition, the present disclosure may represent an LBT process having a fixed time length of 25 μs as "LBT type B". In addition, the present disclosure may represent an LBT process having a fixed time length of 16 μs as "LBT type C". As described above, LBT type A may have a CO configuration (CO length in an exemplary embodiment) that varies according to the LBT type or LBT parameter. In addition, LBT type C may be defined as one of the LBT types, but this may mean that the terminal may not actually perform the LBT process, and the terminal does not transmit a signal / channel within a fixed time of 16 μs.

[0101] A communication node (e.g., a transmitting node) that performs an LBT operation may transmit CO information (e.g., CO configuration information) ensured by the LBT operation to another communication node (e.g., a receiving node). The CO configuration information may include LBT parameters for the LBT operation of the terminal. The LBT parameters may include information on the priority class. The CO configuration information may include at least one of start time information of the CO, length information of the CO, or end time information of the CO. In the present disclosure, the term "time point" and the term "time" may be used with the same meaning.

[0102] The receiving node may receive the CO configuration information from the transmitting node and identify the LBT parameters for ensuring the CO based on the CO configuration information. The receiving node may identify the priority class of the CO initiated by the transmitting node based on the LBT parameters.

[0103] In addition, the transmitting device may transmit information on the CO ensured by the LBT process to the receiving device. The information on the CO (e.g., CO configuration information) may include one or more of start time information of the CO, time length information of the CO, and end time information of the CO. The receiving device may transmit a signal / channel at any time within the CO using the indicated CO configuration information.

[0104] The transmitting device may configure a COT based on the LBT type "LBT type A". The COT may indicate a time resource, a frequency resource, or a time-frequency resource. The COT may be referred to as a CO or a channel occupancy resource (COR). Since the time-frequency resources in the unlicensed band are shared with other communication nodes, a specific communication node may use the time-frequency resources discontinuously. Therefore, the transmission of signals / channels in the unlicensed band may occur in a discontinuous burst form. Here, the burst form may represent a transmission structure configured with one or more time slots. In addition, the burst form may also include a transmission structure composed of consecutive OFDM symbols, and the length of this transmission structure is shorter than the time slot length. In sidelink communication, transmission resources may be continuously configured during the COT.

[0105] Figure 10 is a conceptual diagram showing a first exemplary embodiment of the channel occupancy time in a communication system.

[0106] Referring to Figure 10 , the transmitting device may transmit an initial signal and / or a burst signal (e.g., PSSCH, PSFCH, PSCCH, reference signal) within the COT. Here, the initial signal may be a signal copied from the first symbol transmitted from the sidelink. Alternatively, the initial signal may be a signal configured as a cyclic prefix.

[0107] Figure 11 is a conceptual diagram showing a second exemplary embodiment of the channel occupancy time in a communication system.

[0108] Referring to Figure 11 , the transmitting device may transmit PSCCH and / or a burst signal within the COT.

[0109] Hereinafter, the present disclosure will describe a method for allocating sidelink transmission resources and control information related to the allocation. First, the present disclosure will describe resource allocation (RA) as a method for allocating sidelink transmission resources. Transmission resources for transmitting or receiving signals / channels may be allocated to sidelink terminals.

[0110] The SL resources may be allocated based on mode 1 or mode 2. Mode 1 may be referred to as resource allocation (RA) mode 1, and mode 2 may be referred to as RA mode 2. When using RA mode 1, the base station may transmit DCI (e.g., SL grant) including SL resource allocation information to the terminal, and the terminal may perform SL communication using the SL resources allocated by the base station. When using RA mode 2, the terminal may perform a resource sensing operation within a resource pool, perform a resource selection operation on the resources sensed by the resource sensing operation, and perform SL communication using the resources selected by the resource selection operation.

[0111] In RA mode 1, when there is data to be transmitted, the terminal may transmit a scheduling request (SR) for the transmitted data to the base station, and the base station may allocate resources (e.g., SL resources) to the terminal using dynamic grant (DG) based on the SR of the terminal. In RA mode 1, the base station may allocate periodic resources to the terminal in a semi-static manner, and the terminal may perform SL communication using the periodic resources allocated by the base station.

[0112] The periodically allocated resources in a semi-static manner can be configured grant (CG) resources. The base station can transmit the allocation information of the CG resources to the terminal. The allocation information of the CG resources can include at least one of the location information of the CG resources, the time resource information of the CG resources, the frequency resource information of the CG resources, or the periodic information of the CG resources. According to the release process or deactivation process of the CG resources, the CG scheme can be divided into CG-Type1 and CG-Type2. In CG-Type1, the CG resources can be released through RRC signaling. In CG-Type2, the CG resources can be deactivated through DCI signaling.

[0113] In RA mode 2, the terminal can perform a resource sensing operation during the sensing window, select resources that meet predefined conditions from the resources sensed by the resource sensing operation, and use the selected resources to transmit SL signals / channels. The resource sensing / selection method according to RA mode 2 can be divided into a dynamic scheme and a semi-static scheme. According to the semi-static scheme, specific time resources can be occupied. The dynamic scheme and the semi-static scheme can be distinguished according to the time of selecting new resources. When using the dynamic scheme, the terminal can select resources for TB transmission each time it wants to transmit a new TB. The TB transmission can include 'new TB transmission (e.g., initial TB transmission)' and / or 'TB retransmission'. One or more resources (e.g., one or more transmission resources) can be used, occupied, and / or reserved for TB transmission.

[0114] When using the semi-static scheme, the counter value of the TB transmission can be 0 during a specific time (e.g., resource reservation interval (RRI)). Alternatively, when using the semi-static scheme, new transmission resources can be selected under specific conditions. The counter value of the TB transmission can be randomly selected. When a TB transmission (e.g., new TB transmission and / or TB retransmission) is completed, the selected counter value can be decreased by 1. When using the semi-static scheme, the terminal can continue to occupy the selected resources within a specific time. In other words, the terminal can continue to use the selected resources within a specific time. The specific time can represent the time during which the terminal can exclusively occupy. The specific time can be defined as RRI.

[0115] The base station can transmit an RRI list to the terminal. The RRI list can include up to 16 RRIs (e.g., up to 16 RRI values). The signaling can be at least one of system information (SI) signaling, RRC signaling, MAC CE signaling, or PHY signaling. The terminal can receive the RRI list from the base station, select one RRI from the RRIs belonging to the RRI list, and use the selected resources (e.g., selected transmission resources) during the selected RRI. The terminal can occupy continuous resources during the RRI. The continuous resources can be configured in the logical resource area of the SL.

[0116] The first terminal may transmit a SCI including information on the selected RRI to the second terminal. The second terminal may receive the SCI from the first terminal and identify the RRI selected by the first terminal based on the information element included in the SCI. The second terminal may not select the resources during the RRI (e.g., the resources selected by the first terminal) indicated by the SCI. Information on the resources selected by the first terminal may be included in the SCI.

[0117] When using RA mode 2, a resource sensing window and / or a resource selection window may be configured. The resource sensing window may be referred to as a sensing window (SSW), and resource sensing operations may be performed within the SSW. The resource selection window may be referred to as a selection window (SLW), and resource selection operations may be performed within the SLW. Resources used during the RRI (e.g., RRI value) indicated by the SCI may be identified through the resource sensing operations performed in the SSW.

[0118] The SCI may include scheduling information (e.g., scheduling information of the TB) and / or parameters applied to the transmission of the TB. The parameters applied to the transmission of the TB may be used to perform demodulation / decoding of the TB at the receiving terminal. The SCI may be divided into a first-phase SCI (1st SCI) and a second-phase SCI (2nd SCI). The first-phase SCI may be transmitted on the PSCCH, and the second-phase SCI may be transmitted on the PSSCH. The second-phase SCI may be associated with the first-phase SCI. The first-phase SCI may include scheduling information for the initial TB transmission and / or scheduling information for the TB retransmission. The second-phase SCI may include at least one of information on the transmitting terminal of the PSSCH, information on the receiving terminal of the PSSCH, HARQ feedback information, or retransmission information.

[0119] Y transmission resources including the time slot for transmitting the first-phase SCI may be configured. Y may be a natural number. For example, Y may be 2 or 3. The first transmission resource among the Y transmission resources may be configured in the time slot for transmitting the first-phase SCI. In other words, the first transmission resource among the Y transmission resources may be the time slot for transmitting the first-phase SCI. The time slots for configuring the remaining (Y - 1) transmission resources may be defined by a time slot offset. The time slot offset may be a positive integer. The maximum value of the time slot offset may be 32.

[0120] The scheduled first transmission resource may include N subchannel sub-channels in the frequency domain. The first sub-channel among the N subchannel sub-channels (e.g., the starting sub-channel) may be the sub-channel for transmitting the first-phase SCI. N subchannel may be a natural number. N subchannelIt can be set to be equal to or less than the maximum number of sub-channels set by the high-layer signaling. The first-phase SCI can include frequency resource information of the second transmission resource (e.g., information of N sub-channels, information of the starting sub-channel in N sub-channels) and / or frequency resource information of the third transmission resource (e.g., information of N sub-channels, information of the starting sub-channel in N sub-channels). The number of sub-channels N of the second transmission resource can be the same as the number of sub-channels N of the first transmission resource. subchannel The same. The number of sub-channels N of the third transmission resource can be the same as the number of sub-channels N of the first transmission resource. subchannel The same. The first transmission resource among the Y transmission resources can be the transmission resource for the first TB transmission (e.g., initial TB transmission). The remaining (Y - 1) transmission resources can be the transmission resources for TB retransmission.

[0121] The first-phase SCI can include one or more information elements defined in Table 1 below.

[0122] [Table 1]

[0123]

[0124]

[0125] The second-phase 2SCI can include one or more information elements. The information elements included in the second-phase SCI can vary according to the format of the second-phase SCI. The second-phase SCI can include one or more information elements defined in Table 2 below.

[0126] [Table 2]

[0127] Information element HARQ process number New data indicator (NDI) Redundancy version (RV) Source ID Destination ID HARQ feedback enable / disable indicator Transmission type indicator Other information element

[0128] In addition, the frequency-domain / time-domain signal / channel configuration or time-domain signal / channel configuration of the transmission resource allocated to or selected by the terminal can be as follows. As an exemplary embodiment, the signal / channel configuration of the PSSCH for TB transmission can be continuous OFDM symbols within the transmission resource. Hereinafter, "symbol" can refer to "OFDM symbol". The terminal can configure and transmit the PSSCH through continuous symbols within a time slot period or transmission resource. The continuous symbols can include demodulation reference signals (DMRS) for signal demodulation. The terminal can not configure the PSSCH or can not transmit the PSSCH in the symbols that satisfy the following conditions. Here, the conditions can include one or more of the following conditions.

[0129] - The PSSCH cannot be configured or transmitted in symbols other than the symbols configured for the sidelink.

[0130] ○ Here, symbols for the sidelink can be defined based on the SL start symbol (e.g., sl-StartSymbol) and the SL symbol length (e.g., sl-LengthSymbols). Here, the SL start symbol can indicate the index of the first symbol in a continuous sequence of symbols as long as the SL symbol length. Here, the PSSCH allocation can start from the symbol indicated by the index (SL start symbol + 1). Here, a symbol for automatic gain control (AGC) can be configured at the position indicated by the SL start symbol. This symbol can be configured to be the same as the symbol indicated by the index (SL start symbol + 1).

[0131] - The PSFCH can be configured in any time slot. If the PSFCH is configured in any time slot, then the PSSCH cannot be configured or transmitted in the symbols in which the PSFCH is configured. Here, the time slot in which the PSFCH is configured can be a time slot configured periodically (e.g., 1, 2, or 4) according to the PSFCH configuration. Here, the periodicity can be applied within a set of time slots configured for the sidelink.

[0132] - The PSFCH can be configured in any time slot. If the PSFCH is configured in any time slot, then the PSSCH cannot be configured or transmitted in the symbol immediately preceding the symbol in which the PSFCH is configured.

[0133] - The PSSCH cannot be configured in the last symbol among the symbols configured for the sidelink.

[0134] In the above description, symbols not included in the PSSCH configuration during a transmission resource or a time slot period can be referred to as "gap symbols" or "gap OFDM symbols". Additionally, the sidelink can be a link between terminals. Therefore, the received signal strength can vary according to the positions of the transmitting terminal and the receiving terminal. Therefore, AGC may be required to ensure that the signal is input to the receiver at an appropriate level according to the received signal strength. The AGC symbol can be included in the first symbol of the PSCCH / PSSCH transmission. Additionally, the AGC symbol can be configured at the symbol position before the PSFCH transmission. In addition to the AGC symbol, the time required for transmission after signal reception can also be configured as a "gap symbol". Therefore, the last symbol transmitted or the last symbol of the time slot can be configured as a gap symbol. Additionally, even in a time slot in which PSCCH / PSSCH symbols and PSFCH symbols are configured, a gap symbol can be configured after the last PSCCH / PSSCH symbol.

[0135] When configuring a gap symbol in a sidelink transmission in an unlicensed band, if the time of the gap symbol is longer than a predetermined time length, the resource can be occupied by another device in the unlicensed band. Therefore, when using physically continuous resources in the unlicensed band, the gap symbol may not be configured. In addition, a specific number of samples of a previous symbol or a subsequent symbol can be copied and configured as a cyclic prefix or a cyclic suffix, such that the gap symbol is configured to have a length less than one symbol length.

[0136] The length of the cyclic prefix can be a predefined value. Alternatively, the length of the cyclic prefix can be a value specified by the SCI. When performing transmission using time - continuous time slots, the terminal can transmit the cyclic prefix by advancing the cyclic prefix of the first symbol of the time slot after the previously transmitted time slot by a predefined length without an SCI indication.

[0137] In addition, the PSFCH can be configured periodically within the SL resource region. The time slot in which the PSFCH is configured can be referred to as the PSFCH time slot. The PSFCH time slot can be configured according to a periodicity. The period of the PSFCH time slot can be referred to as the PSFCH transmission occasion resource (PSFCH TPR). The PSFCH TRP can be configured as 1 time slot, 2 time slots, or 4 time slots. The PRBs capable of performing PSFCH transmission in the frequency domain can be indicated by a bitmap. The PRBs that can be used for PSFCH transmission can be all PRBs or some PRBs. One PSFCH can be transmitted in one PRB. Alternatively, in the unlicensed band, one PSFCH can be transmitted in one or more PRBs.

[0138] The PRB for transmitting the PSFCH can be determined based on the position of the time slot for receiving the PSSCH associated with the PSFCH. The difference (e.g., time slot offset, interval) between the time slot for receiving the PSSCH and the time slot for transmitting the PSFCH can be considered. For example, the PSFCH can be transmitted in the first PSFCH time slot after K time slots starting from the time slot n for receiving the PSSCH. The PRB index (e.g., the index of the PRB for transmitting the PSFCH) can be defined based on the function f(P PSFCH ,n,K,k subch ). P PSFCH can be the periodicity of the PSFCH. n can be the index of the time slot for receiving the PSSCH. K can be the time slot offset for determining the PSFCH time slot for transmitting the PSFCH. k subch can be the index of the sub - channel for configuring the PSCCH. In the unlicensed band, a set of interleaved PRBs can enable X PRBs. In this case, the number of sets of interleaved PRBs can be 10 or less.

[0139] In the function f(.) for determining the PRB index, at least one of different codes q, the identifier (ID) of the transmitting terminal, or the ID of the receiving terminal that transmits the PSFCH may be considered. The code q may be defined by a cyclic shift or a cyclic shift pair. The cyclic shift may be associated with different Zadoff-Chu sequences. The cyclic shift pair may refer to a pair of different sequences according to an acknowledgement (ACK) or a negative acknowledgement (NACK).

[0140] The PRB set for PSFCH transmission may be determined based on the time slot n in which the PSSCH is transmitted and / or the index of the subchannel in which the PSSCH is transmitted. The PRB in the PRB set and the code carried by the PSFCH may be determined based on a function that considers at least one of the ID of the transmitting terminal or the ID of the receiving terminal that transmits the PSFCH.

[0141] In addition, the resource block set (RB set) may be as follows. The LBT operation using the unlicensed band may be performed in any bandwidth unit. The present disclosure may define any bandwidth used to perform the LBT operation as the LBT bandwidth (LBT BW). In an exemplary embodiment, the LBT bandwidth may be 20 MHz. The frequency domain size of the sidelink resource pool may be larger than the LBT bandwidth. In this case, multiple LBT bandwidths may be configured in the resource pool. Alternatively, multiple RB sets may be configured in the resource pool.

[0142] In this case, any size of bandwidth or PRB may be regarded as a guard band (GB) for filtering between RB sets or between LBT bandwidths. The guard band may be configured between two adjacent RB sets.

[0143] The subchannels of the sidelink may be configured with one or more PRBs as described above. Depending on how the RB set and the guard band are configured, any PRB in any subframe may not be included in the RB set but may be included in the guard band. In this case, different subchannels in one RB set may be configured with different numbers of PRBs. As an exemplary embodiment, a subchannel having fewer PRBs than other subchannels may be used for other purposes. As an exemplary embodiment, a subchannel having fewer PRBs than other subchannels may be a common subchannel. Here, the common subchannel may be used for the terminal to transmit any signal or sequence. This may be considered to satisfy the technical condition of occupying more than a certain bandwidth within the LBT bandwidth.

[0144] In addition, the resources for PSCCH / PSSCH transmission used by the terminal can be configured based on sub-channels. A sub-channel can be configured with a certain number of physically consecutive PRBs. Alternatively, a sub-channel can be configured with a certain number of PRBs that are physically spaced apart at regular intervals in the frequency domain. A sub-channel configured with consecutive PRBs can be defined as a "C sub-channel". A sub-channel configured with PRBs spaced apart at regular intervals can be defined as an "I sub-channel".

[0145] To summarize the above, the resources for sidelink in the unlicensed band can be configured with RB sets, and each RB set is a unit obtained by adding the LBT bandwidth and the guard band in the resource pool. An RB set can include multiple sub-channels. According to the configuration of the guard band, any sub-channel in the sub-channels of the same RB set can have a smaller number of PRBs than other sub-channels.

[0146] In the case of an I sub-channel, according to the subcarrier spacing (SCS), any sub-channel in the sub-channel can have a smaller number of PRBs than other sub-channels. Here, a sub-channel with a smaller number of PRBs than other sub-channels can be defined as an "r sub-channel".

[0147] Figure 12 is a conceptual diagram showing a first exemplary embodiment of an RB set and sub-channels.

[0148] Referring to Figure 12 , the bandwidth obtained by adding the guard band to the LBT bandwidth can be the same as the bandwidth of the RB set. Therefore, the bandwidth obtained by adding the first guard band to the first LBT bandwidth can be the same as the bandwidth of RB set #A. In addition, the bandwidth obtained by adding the second guard band to the second LBT bandwidth can be the same as the bandwidth of RB set #A+1. Consecutive PRBs can configure a C sub-channel. PRBs spaced apart at regular intervals can configure an I sub-channel. In Figure 12 , the sub-channel (i.e., the C sub-channel with index 4) distinguished by a thick line in the C sub-channel can be an r sub-channel. In addition, the I sub-channel with index 3 in the I sub-channel can be an r sub-channel.

[0149] PSCCH can be configured to have PRBs with low indices in each sub-channel. In this case, the starting point of each RB set can coincide with the starting point of the first sub-channel. Therefore, the terminal can minimize the complexity of performing PSCCH blind detection.

[0150] Referring to Figure 12, RB set #A can start from the first PRB of the subchannel with index 0. Additionally, RB set #A + 1 can start from the first PRB of the subchannel with index 5. As an exemplary embodiment, the subchannel index of the I subchannel can be configured independently of the starting PRB of the RB set. In this example, indices 5, 6, 7, 8, and 9 can be defined as indices 0, 1, 2, 3, and 4. The terminal can identify the position of the RB set in the resource pool.

[0151] In an exemplary embodiment, the terminal can identify the frequency-domain starting position of each RB set by considering the LBT bandwidth of the starting PRB from the resource pool. The base station can configure the resource pool by considering multiples of the LBT bandwidth to achieve efficient resource usage. Alternatively, the base station can provide the terminal with information about the index of the starting PRB of the first RB set, information about the PRB periodicity of the RB set, and / or information about the number of PRBs in the RB set.

[0152] Furthermore, the base station can provide the terminal with information about the PRBs included in the guard band. Here, the information about the PRBs included in the guard band can include information about the number of PRBs included in the guard band, information about the index of the PRBs included in the guard band, and / or information about the index of the subchannels included in the guard band and the number of PRBs in the corresponding subchannels. As an exemplary embodiment, the terminal can calculate the position of each RB set based on the PRB periodicity of the RB set and the starting position of the first PRB. The terminal can use information such as the number of PRBs in the guard band or the index of the PRBs in the guard band to identify the subchannel including the guard band.

[0153] The terminal can calculate the transport block size (TBS) by considering the PRBs in the subchannels included in the guard band that are not used for PSSCH transmission. As an exemplary embodiment, the base station can provide the terminal with information about the number of PRBs included in the guard band. In this case, the number of PRBs included in the guard band can be N GB . Here, N GB can be 0 or a positive integer.

[0154] The RB set can include N subch subchannels. Here, N subch can be a positive integer. In each RB set, the subchannel index starts from 0. Thus, in the C subchannel structure, the terminal can use all the PRBs of the subchannels with indices from 0 to (N subch - 2) for PSSCH / PSCCH transmission. Conversely, in the C subchannel structure, the terminal can refrain from using the N subch PRBs of the subchannel with index [N GB - 1] for PSSCH / PSCCH transmission.

[0155] In the I sub-channel structure, the terminal can perform PSSCH / PSCCH transmission using all the PRBs of the sub-channels with indices from 0 to (N subch -N GB -1). Conversely, one PRB of each of the sub-channels with indices from (N subch -N GB ) to (N subch -1) can be used as a guard band. Therefore, the terminal may not be able to perform PSSCH transmission using all the PRBs of the sub-channels with indices from (N subch -N GB ) to (N subch -1). The terminal can identify the number of PRBs to be considered for TBS determination according to the calculation method of the above exemplary embodiment.

[0156] In addition, the terminal can receive scheduling information of the sub-channels belonging to two consecutive RB sets from the base station. In this case, the terminal can determine the unallocated guard band. For example, referring to Figure 12 , the terminal can receive scheduling information of the sub-channels with indices from 0 to at least 5 from the base station. In this case, the terminal can determine the PRBs that are not used as guard bands.

[0157] In addition, the scheduling method can be defined according to the method of defining the indices of the respective sub-channels. The method of defining the index of each sub-channel according to the first exemplary embodiment can be a method of sequentially increasing the index of the sub-channels starting from the sub-channels included in the RB set with the lowest PRB index.

[0158] The method of defining the index of each sub-channel according to the second exemplary embodiment can be a method of indexing the sub-channels in each RB set starting from 0. In this case, the sub-channel indices of each RB set can be distinguished by considering the RB set index of each RB set together. Here, the index of each sub-channel can be defined starting from 0 across different RB sets. In this case, the scheduling information can be defined by the scheduled RB set and the sub-channel index scheduled in the RB set. If adjacent RB sets are scheduled, the PRBs between the RB sets can also be used for PSSCH transmission. Therefore, all the PRBs in the guard band located between adjacent RB sets can be used for PSSCH transmission.

[0159] The in-cell guard band may not be used for sub-channel configuration. The operations of the terminal on the in-cell guard band or the PRBs in the r sub-channel may be defined as follows. In the configuration of the I sub-channel and / or the C sub-channel, the PRBs of the guard band between the inter-cell RB sets may include some PRBs of some sub-channels with some I sub-channel indices. In the configuration of the I sub-channel and / or the C sub-channel, the PRBs of the guard band between the inter-cell RB sets may include some PRBs of some sub-channels with some C sub-channel indices. In addition, the PRBs expected to configure the PSCCH may be included in the PRBs of the guard band.

[0160] In the case of the I sub-channel, the PRBs with high (high value) PRB indices may be included in the guard band. In this case, some PRBs with high indices of the I sub-channel may be included in the guard band. When the sub-channel is scheduled, the terminal may assume one or more of the following defined combinations in PSSCH / PSCCH transmission, TBS determination, etc.

[0161] - When transmitting the PSSCH, the terminal may assume that the TB or data of the corresponding PRB is transmitted through puncturing processing.

[0162] - The downlink or sidelink control information may include information on whether the PRBs included in the guard band of the sub-channel are included in the TB or data transmission or excluded from the TB or data transmission. In addition, when the TB or data transmission includes the PRBs included in the guard band of the sub-channel, the terminal may assume puncturing.

[0163] - The information on whether the PRBs included in the guard band of the sub-channel are included in the TB or data transmission or excluded from the TB or data transmission may be defined or configured through RRC messages.

[0164] - As described above, the information on the sub-channels included in the guard band may be defined or configured in the terminal through RRC messages.

[0165] - The PRBs excluded from the PSSCH transmission may not be included in the number of PRBs considered for TBS determination. Alternatively, if the proportion or number of the excluded PRBs is equal to or higher than a specific proportion or equal to or greater than a specific number, the terminal may not include these excluded PRBs in the number of PRBs considered for TBS determination.

[0166] In the case of the I sub-channel, the PRBs with small (small value) PRB indices may be included in the guard band. In this case, some PRBs with small indices of the I sub-channel may be included in the guard band. When the sub-channel is scheduled, the terminal may assume one or more of the following defined combinations in PSSCH / PSCCH transmission, TBS determination, etc.

[0167] - When transmitting the PSSCH, the terminal may assume that the TB or data of the corresponding PRB is transmitted through puncturing processing.

[0168] - The downlink or sidelink control information may include information on whether the PRBs included in the guard band of the subchannel are included in the TB or data transmission or excluded from the TB or data transmission. The PRBs included in the guard band of the subchannel may be included in the TB or data transmission. In this case, puncturing may be assumed.

[0169] - Information on whether the PRBs included in the guard band of the subchannel are included in the TB or data transmission or excluded from the TB or data transmission may be defined or configured by an RRC message.

[0170] - As described above, the information on the subchannels included in the guard band may be defined or configured in the terminal by an RRC message.

[0171] - The PRBs excluded from the PSSCH transmission may not be included in the number of PRBs considered for TBS determination. Alternatively, if the proportion or number of the excluded PRBs is equal to or higher than a specific proportion or equal to or greater than a specific number, the terminal may not include these excluded PRBs in the number of PRBs considered for TBS determination.

[0172] - The PSCCH transmission may be performed in the reverse order starting from the PRBs with high indices in the subchannel.

[0173] In addition, in the case of the C subchannel, the subchannels with high (high value) indices may be included in the guard band. When the subchannel is scheduled, the terminal may assume one or more of the following defined combinations in the PSSCH / PSCCH transmission, TBS determination, etc.

[0174] - When transmitting the PSSCH, the terminal may assume that the TB or data of the corresponding PRB is transmitted through puncturing processing.

[0175] - The downlink or sidelink control information may include information on whether the PRBs included in the guard band of the subchannel are included in the TB or data transmission or excluded from the TB or data transmission. When the TB or data transmission includes the PRBs included in the guard band of the subchannel, the terminal may assume puncturing.

[0176] - Information on whether the PRBs included in the guard band of the subchannel are included in the TB or data transmission or excluded from the TB or data transmission may be defined or configured by an RRC message.

[0177] - As described above, the information of the subchannels included in the guard band can be defined or configured in the terminal through RRC messages.

[0178] - The PRBs excluded from PSSCH transmission may not be included in the number of PRBs considered for TBS determination. Alternatively, if the proportion or number of the excluded PRBs is equal to or higher than a specific proportion or equal to or greater than a specific number, the terminal may not include these excluded PRBs in the number of PRBs considered for TBS determination.

[0179] In addition, in the case of C subchannels, the subchannels with low (low value) indices may be included in the guard band. When scheduling subchannels, the terminal may assume one or more of the following combinations defined below in PSSCH / PSCCH transmission, TBS determination, etc.

[0180] - When transmitting PSSCH, the terminal may assume that the TB or data of the corresponding PRB is transmitted through puncturing processing.

[0181] - The downlink or sidelink control information may include information on whether the PRBs included in the guard band of the subchannel are included in the TB or data transmission or excluded from the TB or data transmission. When the TB or data transmission includes the PRBs included in the guard band of the subchannel, the terminal may assume puncturing.

[0182] - The information on whether the PRBs included in the guard band of the subchannel are included in the TB or data transmission or excluded from the TB or data transmission can be defined or configured through RRC messages.

[0183] - As described above, the information of the subchannels included in the guard band can be defined or configured in the terminal through RRC messages.

[0184] - The PRBs excluded from PSSCH transmission may not be included in the number of PRBs considered for TBS determination. Alternatively, if the proportion or number of the excluded PRBs is equal to or higher than a specific proportion or equal to or greater than a specific number, the terminal may not include the PRBs excluded from PSSCH transmission in the number of PRBs considered for TBS determination.

[0185] - PSCCH transmission may start from the PRBs with high indices in the subchannel in the reverse order.

[0186] The transmission or reception of PSSCH or PSCCH in the C subchannel or I subchannel including the PBR designated or configured as the in-cell guard band will be described in more detail below with reference to exemplary embodiments. The PRBs in the guard band can be used for PSSCH configuration. However, the PRBs in the guard band cannot be used for PSCCH.

[0187] Exemplary embodiments of PSCCH configuration may be as follows. The terminal may identify the time-domain symbol position and the number of PRBs from the higher-layer messages sl-TimeResourcePSCCH and sl-FreqResourcePSCCH that determine the PSCCH resources. Here, the number of PRBs may represent the number of PRBs starting from the next PRB after excluding the PRBs used as the guard band. Here, the PSSCH may be configured to include the PRBs used as the guard band. Thus, in the subchannel configured with the PRBs of the guard band, the PSCCH may be configured starting from the next lower PRB after excluding the PRBs of the guard band of the subchannel, including the PRBs of the associated PSSCH.

[0188] Another exemplary embodiment of PSCCH configuration may be as follows. This may be the case where the SCI format 1-A includes information about the start portion of the subchannel for the PSCCH / PSSCH. Here, the exemplary embodiment may assume the case where the subchannel including the guard band PRBs is used for the PSSCH, and the PSCCH is configured in the subchannel whose index is immediately after this subchannel.

[0189] Based on the above information, the terminal may determine that the PSSCH is configured starting from a subchannel with an index lower than that of the subchannel where the PSCCH is detected. Here, the bits indicating the above information may be configured and indicated in the SCI format 1-A. The indication bit is expected to be configured in the SCI format 1-A only when it comes to within a cell composed of two or more RB sets. Other bits indicating the above information may be defined as a combined code in the frequency resource indication value (FRIV) for scheduling the PSSCH subchannel resources, or may be defined according to any rule. Alternatively, it may be defined as a combined code in the FRIV for scheduling the RB set resources, or may be defined according to any rule.

[0190] Another exemplary embodiment of PSCCH configuration may be as follows. If the PSCCH is configured in the subchannel after the subchannel including the guard band PRBs according to the configuration of the higher-layer message, it may be determined that the subchannel including the guard band PRBs is included in the PSSCH transmission. Alternatively, it may be indicated as "the lowest index of the subchannel assigned to the initial transmission" in the SCI format 1-A. Alternatively, a new field may be defined in the SCI format 1-A to indicate that the start subchannel of the PSSCH resources starts from the previous subchannel.

[0191] Another exemplary embodiment of the PSCCH configuration may be as follows. This may correspond to an example where the PSCCH is configured at the center of the subchannels constituting the PSSCH. As an exemplary embodiment, when X subchannels are configured, the PSCCH may be configured in the (Floor(X / 2))-th or (Floor(X / 2)-1)-th subchannel among the X subchannels. Alternatively, when considering the start of the X subchannels as 0, the PSCCH may be configured in the (Floor(X / 2))-th or (Floor(X / 2)-1)-th subchannel.

[0192] The second or third resource may be indicated by resource reservation, and in the case where the start subchannel includes a guard band, the terminal may expect to configure the PSCCH from the start PRB of the subchannel immediately following the subchannel including the guard band. Alternatively, the second or third resource may be indicated by resource reservation, and in the case where the start subchannel includes a guard band, the terminal may expect to configure the PSCCH from the PRB immediately following the guard band PRB.

[0193] In addition, the scheduling may include reservation of two or three resources. The terminal may identify the subchannel start index of the first resource by detecting the PSCCH. The terminal may identify the second index or the second and third indexes and the number of subchannels from the frequency resource allocation information (FRIV) provided by the SCI. When following the definition of "subchannel index" in the first exemplary embodiment, the terminal may identify the start position of the allocated subchannels according to the sequential index. The number of subchannels of all subchannels of the first, second, and third subchannels may be the same. When following the definition of "subchannel index" in the second exemplary embodiment, the terminal may identify the RB set index and the subchannel index of each transmission resource. As an exemplary embodiment, the number of subchannels L in the FRIV subch may include information about the number of subchannels used in one RB set and the number of RB sets. That is, the number of used RB sets and subchannels may be jointly defined in L subch Here, the resources may be determined by the index starting from the RB set index of the RB set where the PSCCH is detected and the subchannel index of the subchannel where the PSCCH is detected. When the RB set reaches the last index, the RB set with the RB set index calculated by modulo operation may be determined. In addition, for the second index or the second and third indexes, the start RB set index and the subchannel index are jointly defined in one variable.

[0194] Additionally, the transmission time and its resource structure of PSCCH / PSSCH can be defined according to the SL-start symbol (e.g., sl-StartSymbol) and SL symbol length (e.g., sl-LengthSymbols) as described above. Additionally, PSFCH can be included in any time slot according to the PSFCH transmission period. As described above, if sidelink is configured in the unlicensed band, an LBT operation may be required to be performed before transmission. According to the result of the LBT operation, the PSCCH / PSSCH transmission may not be performed. Additional transmission time (or time point or timing) can be defined to ensure the transmission opportunity. This disclosure will be described by taking two transmission times, "transmission time-A" and "transmission time-B", as examples.

[0195] The first terminal can transmit a signal / channel to the second terminal using the SL transmission method. The second terminal can receive the signal / channel from the first terminal using the SL reception method. The first terminal can transmit a TB on the PSSCH. The first terminal can transmit control information on the PSSCH. The control information can include information elements required for demodulating and / or decoding the TB transmitted on the PSSCH. The first terminal can transmit control information on the PSCCH. The second terminal can receive the control information from the first terminal and identify resource usage information based on the control information. The second terminal can receive the PSSCH (e.g., TB) and transmit HARQ-ACK feedback (e.g., HARQ feedback, HARQ response) for the PSSCH to the first terminal. The HARQ-ACK feedback for the PSSCH can be transmitted on the PSFCH.

[0196] In this disclosure, a terminal that performs PSCCH transmission, PSSCH transmission, and / or PSFCH reception may be referred to as a transmitting terminal or a first terminal, and a terminal that performs PSCCH reception, PSSCH reception, and / or PSFCH transmission may be referred to as a receiving terminal or a second terminal.

[0197] In SL-U communication, a terminal may perform an LBT operation before transmitting a signal / channel. If the result of the LBT operation indicates an idle state, the terminal may transmit the signal / channel. If the result of the LBT operation indicates a busy state, the terminal may not transmit the signal / channel. "The result of the LBT operation indicates an idle state" may mean that the LBT operation is successful. "The result of the LBT operation indicates a busy state" may mean that the LBT operation fails. Based on the comparison result between the detected energy level and a predefined threshold, it can be determined whether the result of the LBT operation is idle or busy.

[0198] As described above, the terminal can perform the LBT operation immediately before transmitting the PSCCH / PSSCH in any time slot. When the LBT operation is successful (i.e., when the channel is not occupied by another signal or channel, etc.), the terminal can transmit the PSCCH / PSSCH based on the transmission time - A of the time slot. When the LBT operation fails (i.e., when the channel is occupied by another signal or channel, etc.), the terminal can transmit the PSCCH / PSSCH based on the transmission time - B of the time slot.

[0199] Figure 13 is a conceptual diagram showing a first exemplary embodiment of the transmission time.

[0200] Referring to Figure 13 , the transmission time - A can correspond to the symbol index of the time slot indicated by the SL start symbol. In this case, the PSCCH / PSSCH symbol can be transmitted in the time slot corresponding to the symbol index of (SL start symbol + 1). Regarding the transmission time - A, the terminal can use one or more of the following exemplary embodiments to determine or configure the transmission time.

[0201] Exemplary embodiment 1) Information about the transmission time - A can be configured by the base station or a higher layer message (e.g., an RRC message, etc.). This information can be set to a single value of 0, 1, 2, 3, 4, 5, or 6.

[0202] Exemplary embodiment 2) Information about multiple transmission times - A can be configured by the base station or a higher layer message (e.g., an RRC message, etc.). Multiple values can be configured as a list. Among the multiple candidate values, the value to be used as the transmission time can be dynamically indicated by the DCI of the base station. Alternatively, the transmission time among the multiple candidate values can be indicated by the SCI of the terminal.

[0203] The transmission time - A defined by one or more of the above methods can be set differently for each BWP. The transmission time - A defined by one or more of the above methods can be set differently for each terminal. In the unlicensed band, the transmission can be determined based on the channel occupancy according to the LBT operation of each terminal. Therefore, the same transmission time - A can be configured for all terminals within the same BWP.

[0204] Here, the transmission time according to the transmission time - A can represent the transmission start time including the AGC symbol.

[0205] Regarding the transmission time - B, the terminal can determine or configure the transmission time in one or more of the following exemplary embodiments.

[0206] Exemplary embodiment 1) It can be the time of (transmission time - A + N offset ).

[0207] Here, Noffset It can be a fixed value or a natural number. N offset An example of the fixed value of N can be 7. Alternatively, N offset can be one of the values 1, 2, 3, 4, 5, 6, or 7.

[0208] Alternatively, N offset value can be set by the base station or a higher layer message (e.g., an RRC message). This value can be set to a single value.

[0209] Alternatively, multiple N offset values can be configured by the base station or a higher layer message (e.g., an RRC message). The value to be applied among these values can be dynamically determined by DCI or SCI.

[0210] Alternatively, the N offset value can be dynamically set for the terminal by including it in DCI or SCI.

[0211] Exemplary embodiment 2) The transmission time - B can be dynamically set for the terminal by including it in DCI or SCI.

[0212] Exemplary embodiment 3) Information about the transmission time - B can be configured by the base station or a higher layer message (e.g., an RRC message, etc.). This information can be set to a single value of 3, 4, 5, 6, or 7.

[0213] Exemplary embodiment 4) Information about multiple transmission times - B can be configured by the base station or a higher layer message (e.g., an RRC message, etc.). Multiple values can be configured as a list. The value used as the transmission time among the multiple candidate values can be dynamically indicated by the DCI of the base station. Alternatively, the transmission time among the multiple candidate values can be indicated by the SCI of the terminal.

[0214] The transmission time - B defined by one or more of the above methods can be set differently for each BWP. The transmission time - B defined by one or more of the above methods can be set differently for each terminal. In the unlicensed band, transmission can be determined based on the channel occupancy status according to the LBT operation of each terminal. Therefore, the same transmission time - B can be configured for all terminals within the same BWP.

[0215] Here, the transmission time according to the transmission time - B can mean the start time of the transmission including the AGC symbol. Alternatively, the transmission time according to the transmission time - B can mean the start time of the valid PSCCH / PSSCH. Alternatively, the transmission time can mean the transmission time of the symbol for AGC. Here, the symbol for AGC can be a replicated symbol of the first valid PSCCH / PSSCH symbol. As an exemplary embodiment, when the symbol index corresponding to the transmission time - B is defined as S IdxWhen, the index of the first valid PSCCH / PSSCH symbol can be S Idx . Alternatively, when symbols for AGC are configured, the index of the first valid PSCCH / PSSCH symbol can be (S Idx + 1). The above-mentioned valid PSCCH / PSSCH can represent the signals / channels configured by the symbols used by the receiving terminal for demodulation and / or decoding.

[0216] As an exemplary implementation, the terminal can occupy the working channel and start transmitting at the time corresponding to N symbols before the transmission time - B (S Idx - N (i.e., (S Idx - N) > 0)) to ensure the transmission opportunity. This allows, after the LBT operation starting at the transmission time - A fails, if the channel is not occupied before the transmission time - B, the terminal to perform the transmission. Here, the terminal can transmit the symbols for AGC copied from the PSCCH / PSSCH to be transmitted. Alternatively, the terminal can configure and transmit the synchronization signal. In this case, the start time of the COT can be defined as the transmission time of (S Idx - N). However, since the above operations may affect the LBT results of other terminals, it may be limited to the cases indicated by the base station. As an exemplary implementation, the DCI of the base station can include whether transmission can be performed before the transmission time - B. If the DCI indicates that transmission can be performed before the transmission time - B, the terminal operating in RA mode 1 by receiving the DCI of the base station can perform the transmission before the transmission time - B according to the LBT result. Alternatively, during a non - COT period, the terminal performing the LBT operation of LBT type A can perform the transmission at the symbols before the transmission time - B without any other configuration information.

[0217] The transmission time - B can be restricted to be valid only under specific conditions. That is, if one or more of the following conditions are met, the terminal can transmit PSCCH / PSSCH at the transmission time - B.

[0218] Condition 1) The case where the time slot is not a PSFCH opportunity

[0219] Here, the PSFCH opportunity can mean the symbols or time slots in which the PSFCH can be configured periodically according to the PSFCH transmission.

[0220] Condition 2) The case of hoping to transmit in the next time slot. Here, the next time slot can represent the next physically consecutive time slot. In addition, the case of hoping to perform the transmission can mean that resources are reserved for this.

[0221] In addition, the terminal may define the PSCCH / PSSCH transmission resource configuration for transmission at transmission time - B as follows. As an exemplary implementation, the symbol length for transmission at transmission time - B may be calculated based on the symbols defined by the SL start symbol and the SL symbol length within a time slot.

[0222] If transmissions are configured continuously in the next time slot, the transmission resources of up to ["SL symbol length" + 1] may be configured for transmissions at transmission time - A and / or transmission time - B. Alternatively, this method may be applied when the consecutive time slots in the resource pool are not physically consecutive time slots. This may mean that the last symbol of the time slot is also used for PSSCH transmission. In other words, this may mean that the last guard symbol is used for PSSCH transmission. Here, within one time slot of the same BWP, the positions of the last symbols, end times, or positions of the end symbols of the transmissions at transmission time - A and transmission time - B may need to be kept the same. In addition, if consecutive time slots are configured, the transmission at transmission time - A may correspond to the time period of the entire transmission resource (i.e., the time period of symbols with indices from 0 to 14 (in the case of normal CP) and the time period of symbols with indices from 0 to 12 (in the case of extended CP)).

[0223] The information on whether to use the last symbol may be provided to the terminal by including it in an information field such as "additional symbol" or "no last guard symbol" in the SCI. When using transmission time - A and / or transmission time - B, whether to use the last symbol or the symbol indexed by ["SL symbol length" + 1] for PSSCH transmission may be applicable. The base station may indicate to the terminal the information on whether to use the last symbol via DCI. The terminal receiving this indication may transmit the PSCCH by setting the SCI field indicating whether to use the last symbol to "enabled". The SCI field may be transmitted by including it in the first - stage SCI. In the case of RA mode 2, the transmitting terminal may transmit the SCI by enabling the field of the SCI. Here, in the case of RA mode 2, it is only applicable when the next time slot after the time slot in the sidelink resource pool is not physically configured continuously. Here, the case of non - physical continuous configuration may mean that a time slot that does not belong to the resource pool appears subsequently. Alternatively, it is only applicable when the resource pools of RA mode 1 and RA mode 2 are configured separately.

[0224] Hereinafter, the present disclosure will describe a method for determining the TBS in a resource pool where both transmission time - A and transmission time - B are configurable. Since the number of symbols configurable as transmission resources varies according to the transmission time, the TBS determination method may be defined based on the symbols configurable by the terminal. The number of resource elements (REs) N' of the PSSCH assigned to one PRB or one sub - channel may be used REto define the TBS. When determining N' RE one or more of the SL symbol length, the number of PSFCH symbols, the number of DMRS REs, and the number of overhead REs may be considered. When the transmission times are different, the SL symbol length for transmission time - A and the SL symbol length for transmission time - B may be different. When the SL symbol length is defined based on transmission time - A and configured in the terminal, the terminal may assume that the symbol positions at the end of the transmission within one time slot according to transmission time - A and transmission time - B are the same. In this case, the symbol position at the end of the transmission may be determined by the SL symbol length of transmission time - A and the SL start symbol. In this case, the terminal may determine the number of symbols for transmission according to the configured transmission time - B. For ease of description, the present disclosure describes the number of symbols for transmission time - A as "transmission time - A - symbol length", and the number of symbols for transmission time - B as "transmission time - B - symbol length". In addition to the above description, the terminal may also receive the symbol length of transmission time - B through an RRC message. When determining the TBS, the SL symbol length of transmission time - A may be used. More specifically, the value obtained by subtracting 2 from the SL symbol length may be considered. In the case of transmission time - B, or in the case of both transmission time - A and transmission time - B, the number of symbols considered for TBS determination may be determined by one or more methods according to the conditions defined in the following exemplary embodiments.

[0225] Condition 1) If the symbol index difference between transmission time - A and transmission time - B is equal to or less than X symbols, the SL symbol length of transmission time - A may be equally considered or applied in the TBS determination for transmission according to transmission time - B. In this case, as in the case of transmission time - A, the value obtained by subtracting 2 from the SL symbol length may be considered. Here, as an exemplary embodiment, X may be a single predefined value. As an exemplary embodiment, X may be 5 and / or 6. Alternatively, the value of X may be a value set in the terminal through an RRC message.

[0226] Condition 2) If the symbol index difference between transmission time - A and transmission time - B is equal to or greater than 5, 6, or 7 symbols, the SL symbol length of transmission time - B may be considered in the TBS determination for transmission according to transmission time - B.

[0227] Condition 3): For a resource pool that can be transmitted according to Transmission Time - A and can also be transmitted according to Transmission Time - B, it is possible to consider using the same SL symbol length for Transmission Time - A and Transmission Time - B. Here, as an exemplary embodiment, the average value of the Transmission Time - A symbol length and the Transmission Time - B symbol length can be considered. As an exemplary embodiment, the largest integer value not exceeding the average value can be considered. As another example, the smallest integer value greater than the average value can be considered. Alternatively, the value of the SL symbol length to be considered for TBS determination can be set through an RRC message.

[0228] Condition 4): For a resource pool that can be transmitted according to Transmission Time - A and can also be transmitted according to Transmission Time - B, if the symbol index difference between Transmission Time - A and Transmission Time - B is equal to or less than X symbols, the same SL symbol length can be considered. If the symbol index difference is greater than X symbols, for transmissions according to Transmission Time - A and according to Time - B, the Transmission Time - A symbol length and the Transmission Time - B symbol length can be considered separately. In the case where the same SL symbol length is considered due to the symbol index difference being less than or equal to X symbols, the average value between the Transmission Time - A symbol length and the Transmission Time - B symbol length can be considered. As an exemplary embodiment, the largest integer value not exceeding the average value can be considered. As another exemplary embodiment, the smallest integer value greater than the average value can be considered. Alternatively, the value of the SL symbol length to be considered for TBS determination can be set through an RRC message.

[0229] Condition 5): For transmissions according to Transmission Time - A, the Transmission Time - A symbol length can be considered, and for transmissions according to Transmission Time - B, the SL symbol length can be set according to Transmission Time - B through an RRC message. As an exemplary embodiment, different symbol lengths can be defined for each symbol index of Transmission Time - B, or the same SL symbol length can be configured for some symbol indexes. Among them, when Transmission Time - B corresponds to symbols with a symbol index lower than a certain value, the SL symbol length of Transmission Time - B can be set to be the same as that of Transmission Time - A.

[0230] Condition 6) can determine the TBS by considering the same reference symbol length for transmission time - A and transmission time - B. Here, as an example, the reference symbol length can be defined as the symbol length defined in the RRC message, and its value can be defined as one value among 7 to 14. Here, when two transmission times can be configured, the reference symbol length defined in the RRC message can be used as the SL symbol length for TBS calculation. Here, the number of AGC symbols and the number of guard symbols can be subtracted from the SL symbol length. If AGC symbols are configured in both transmission time - A and transmission time - B, the number of two AGC symbols, 2, can be subtracted from the SL symbol length. In another exemplary embodiment, regardless of the AGC symbol configuration, only one AGC symbol can be subtracted in both transmission time - A and transmission time - B. When the reference symbol length is defined to be less than the actual length of transmission time - A, this can prevent the AGC from further reducing the symbol length.

[0231] If a guard band is included here, the reference symbol length can be used as the SL symbol length, and the TBS can be calculated by subtracting 2 from the SL symbol length. In addition, the value to be subtracted according to the DMRS mode can be defined as the same value as when there is one transmission time. If it needs to be defined as a different value from when there is only one transmission time, any offset calculated or defined by considering transmission time - A and transmission time - B can be applied to the value according to the DMRS mode when calculating the TBS.

[0232] When considering COT sharing and transmission time - B, it can be expected that there is no PSSCH / PSCCH transmission at transmission time - B during the COT sharing period. Therefore, it can be expected that during COT sharing, except for the UE that initiates the COT, there is no transmission time - B. Here, it can be expected that only one AGC symbol can be configured during the COT sharing period. Therefore, in TBS determination, it can be considered that only one AGC symbol is configured to calculate the TBS. In addition, in the case where only transmission time - A is configured without considering the reference symbol length of the SL symbol length, the TBS can be calculated by considering the resource quantity based on the SL symbol length. Here, when the first PSSCH / PSCCH is transmitted during the COT sharing period and the second or third transmission is performed through resource reservation, the terminal can expect to configure the same TBS as the TBS during the COT sharing period for the second or third transmission.

[0233] For the DMRS configuration in the transmission period, the symbol configuration index of Transmission Time - A can be configured to increase to the index of Transmission Time - B. This index can increase the symbol offset (hereinafter referred to as Noffset) between Transmission Time - A and Transmission Time - B. As an example, the symbol position index of PSSCH DMRS can be set to the index obtained by adding Noffset. In this case, the value in the DMRS index definition table can be used as the index for generating the DMRS sequence.

[0234] Figure 14 is a conceptual diagram showing a first exemplary embodiment of the time - domain symbol configuration.

[0235] Referring to Figure 14 , the first case can be the case where the LBT operation is successful, and can be the case where SL start symbol = 0 and SL symbol length = 13 are given as the information of Transmission Time - A. The information of Transmission Time - A can be configured, and Transmission Time - B can be configured, determined, or calculated to have a symbol index of 7. Here, the terminal can determine the symbol length of Transmission Time - B to be 6.

[0236] The second case can be the case where the LBT operation fails. In the second case, the positions of the DMRS can be 1 and 5. The positions of the DMRS can correspond to symbol indices 8 and 12 within the time slot. That is, the positions of the DMRS can be indexed by the index starting from the symbols used for PSSCH / PSCCH transmission, including the replicated symbols. In this case, the values used for generating the DMRS sequence can be defined as the same values as the position values, i.e., 1 and 5. As another exemplary embodiment, the positions of the DMRS can be calculated as the index value plus Noffset. In this case, the positions of the DMRS can be defined as 1 and 5. However, the values used for generating the DMRS sequence can be defined as 7 and 12 obtained by adding Noffset to the positions of the DMRS.

[0237] The third case can be the case of considering a symbol length of 6 and DMRS maintenance. The SCI can include information indicating that the last symbol is used for PSSCH transmission. In this case, the transmission symbols can be configured as in the second case. The receiving terminal can consider this case to determine the TBS. Performing PSSCH transmission using the symbol indicated as the last guard symbol can be configured in the same way as the transmission of Transmission Time - A. Here, when the next time slot of the currently transmitted time slot is scheduled to the same terminal, the last symbol for PSSCH transmission can be configured.

[0238] This can be configured by the base station to the transmitting terminal via DCI. The transmitting terminal that receives the DCI can include information on the PSSCH in the SCI. The last symbol used for PSSCH transmission can be indicated by defining it as "enabled" in the information.

[0239] Figure 15 is a conceptual diagram showing a second exemplary embodiment of the time-domain symbol configuration.

[0240] Referring to Figure 15 , the transmission time - B can be 4. The number of symbols for transmission performed according to the transmission time - B can be regarded as 9. If PSSCH transmission is enabled in the last symbol, it can correspond to Case 2.

[0241] The operations of the method according to an exemplary embodiment of the present disclosure can be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium can include various recording devices for storing data that can be read by a computer system. In addition, the computer-readable recording medium can store and execute a program or code that can be distributed in computer systems connected via a network and read by a computer in a distributed manner.

[0242] The computer-readable recording medium can include hardware devices specifically configured to store and execute program commands, such as ROM, RAM, or flash memory. The program commands can include not only machine language code created by a compiler but also high-level language code that can be executed by a computer using an interpreter.

[0243] Although certain aspects of the present disclosure have been described in the context of devices, these aspects can indicate corresponding descriptions according to the method, and a block or device can correspond to a step or a feature of a step of the method. Similarly, aspects described in the context of the method can be expressed as features of the corresponding block or item or the corresponding device. Some or all steps of the method can be performed by (or using) hardware devices, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important steps of the method can be performed by such a device.

[0244] In some exemplary embodiments, a programmable logic device, such as a field-programmable gate array, can be used to perform some or all of the functions of the methods described herein. In some exemplary embodiments, the field-programmable gate array can operate with a microprocessor to perform one of the methods described herein. Generally, the method is preferably performed by a specific hardware device.

[0245] The description of the present disclosure is merely exemplary, and thus variations that do not depart from the essence of the present disclosure are intended to be within the scope of the present disclosure. Such variations should not be regarded as departing from the spirit and scope of the present disclosure. Accordingly, those of ordinary skill in the art should understand that various changes may be made in form and detail without departing from the spirit and scope defined by the appended claims.

Claims

1. A method for a first terminal, comprising: configuring a resource block (RB) set from a sidelink resource pool, each RB set corresponding to a unit in which a listen-before-talk (LBT) bandwidth and a guard band are combined; configuring a subchannel including two or more physical resource blocks (PRBs) from among a plurality of PRBs included in each RB set; generating sidelink control information including identification information of at least one scheduled subchannel among a plurality of subchannels configured in the RB set; and transmitting the sidelink control information to a second terminal.

2. The method according to claim 1, further comprising: receiving guard band information from a base station, the guard band information including at least one of information on an index of a PRB of the guard band in the resource pool or information on a number of PRBs of the guard band; and identifying a subchannel including the guard band based on the guard band information.

3. The method according to claim 2, further comprising: The protected band information further includes the number N of PRBs included in the protected band GB when the information of When each RB set includes N subch sub-channels, the PRBs included in the sub-channels with indexes from 0 to (N subch - N GB - 1) are configured for transmission; Configure one PRB in each of the sub-channels indexed from (N subch - N GB ) to (N subch - 1) to be used as the guard band; Configure one PRB in each of the sub-channels indexed from (N subch - N GB ) to (N subch - 1) not to be used for transmission; and calculating a transport block size (TBS) by considering one PRB not used for transmission.

4. The method according to claim 3, wherein when the number of PRBs excluded from transmission is equal to or greater than a predetermined number, the number of PRBs excluded from transmission is considered when calculating the TBS.

5. The method according to claim 1, wherein when the at least one scheduled subchannel is included in each of at least one RB sets, the sidelink control information further includes information on whether to use the guard band for transmission.

6. The method according to claim 1, wherein when the at least one scheduled subchannel is included in each of at least one RB sets, the first terminal assumes that data is punctured and transmitted at the PRBs of the guard band.

7. The method according to claim 1, further comprising: performing a listen-before-talk (LBT) operation before transmitting a signal in a first time slot of the at least one scheduled subchannel; in response to the LBT operation being successful, transmitting a signal to the second terminal based on a first transmission time in the first time slot; and in response to the LBT operation failing, transmitting a signal to the second terminal based on a second transmission time in the first time slot, wherein the first transmission time is a time of a symbol index indicated by sidelink start symbol information, and the second transmission time is a time obtained by adding an offset to the time of the symbol index indicated by the sidelink start symbol information.

8. The method according to claim 7, further comprising: receiving information on a plurality of candidate start symbols from a base station; and configuring information on a start symbol dynamically indicated by the base station among the plurality of candidate start symbols as the sidelink start symbol information.

9. The method according to claim 7, wherein the second transmission time is at least one of a start time including transmission of an automatic gain control (AGC) symbol, a start time of a physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH), or a start time of an AGC symbol.

10. The method according to claim 1, further comprises: determining the transport block size (TBS) by considering at least one of the sidelink symbol length, the number of physical sidelink feedback channel (PSFCH) symbols, the number of demodulation reference signal (DMRS) resource elements (REs), or the number of overhead REs.

11. The method according to claim 7, wherein, when transmitting a second DMRS at the second transmission time, the first terminal transmits the second DMRS at a time obtained by adding an offset to the transmission time of the first DMRS to be transmitted at the first transmission time.

12. A first terminal, comprising a processor, wherein, the processor causes the first terminal to perform: configuring a set of resource blocks (RBs) from a sidelink resource pool, each set of RBs corresponding to a unit in which the listen-before-talk (LBT) bandwidth and the guard band are combined; configuring a subchannel including two or more physical resource blocks (PRBs) from among the plurality of PRBs included in each set of RBs; generating sidelink control information, the sidelink control information including identification information of at least one scheduled subchannel among the plurality of subchannels configured in the set of RBs; and transmitting the sidelink control information to a second terminal.

13. The first terminal according to claim 12, wherein, the processor further causes the first terminal to perform: receiving guard band information from a base station, the guard band information including at least one of information on the index of the PRBs of the guard band in the resource pool or information on the number of PRBs of the guard band; and and identifying a subchannel including the guard band based on the guard band information.

14. The first terminal according to claim 12, wherein, The protected band information further includes the number N of PRBs included in the protected band GB of information, and the processor further causes the first terminal to perform: When each RB set includes N subch sub-channels, the PRBs included in the sub-channels with indexes from 0 to (N subch - N GB - 1) are configured for transmission; Configure one PRB in each of the sub-channels indexed from (N subch - N GB ) to (N subch - 1) to be used as the guard band; Configure one PRB in each of the sub-channels indexed from (N subch - N GB ) to (N subch - 1) not to be used for transmission; and the transport block size (TBS) is calculated by considering one PRB not used for transmission.

15. The first terminal according to claim 12, wherein, the processor further causes the first terminal to perform: performing a listen-before-talk (LBT) operation before transmitting a signal in a first time slot of the at least one scheduled subchannel; in response to the LBT operation being successful, transmitting a signal to the second terminal based on a first transmission time in the first time slot; and and in response to the LBT operation failing, transmitting a signal to the second terminal based on a second transmission time in the first time slot, wherein the first transmission time is the time of the symbol index indicated by the sidelink start symbol information, and the second transmission time is the time obtained by adding an offset to the time of the symbol index indicated by the sidelink start symbol information.

16. The first terminal according to claim 15, wherein, the processor further causes the first terminal to perform: receiving information on a plurality of candidate start symbols from a base station; and configuring information on the start symbol dynamically indicated by the base station among the plurality of candidate start symbols as the sidelink start symbol information.

17. The first terminal according to claim 15, wherein, When continuing transmission in a second time slot that is the next time slot of the first time slot, the first terminal transmits a signal in a transmission resource of a guard symbol at a position obtained by adding 1 to the sidelink symbol length.

18. The first terminal according to claim 17, wherein, the first terminal notifies the second terminal whether to use the guard symbol at the position obtained by adding 1 to the sidelink symbol length through the sidelink control information.

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