METHOD AND APPARATUS FOR PERFORMING SIDELINK COMMUNICATIONS IN A WIRELESS COMMUNICATION SYSTEM - Patent application

Abstract

A method for configuring a sidelink resource pool in a terminal in a wireless communication system, comprising: receiving, by the terminal, resource pool configuration information from a base station based on higher layer signaling; transmitting, by the terminal, sidelink control information to another terminal based on the resource pool configuration information; and performing sidelink communication with the other terminal, wherein the resource pool configuration information may be information based on a sidelink resource pool configuration of an unlicensed band.

Description

[Technical Field]

[0001] The present disclosure relates to a method and apparatus for performing sidelink communication in a wireless communication system. [Background technology]

[0002] The International Telecommunication Union (ITU) is developing the International Mobile Telecommunication (IMT) framework and standards, and recently discussions for fifth-generation (5G) communications have been underway through a program called "IMT for 2020 and beyond."

[0003] To meet the requirements set out in "IMT for 2020 and beyond," the 3GPP (registered trademark) 3rd Generation Partnership Project (NR) New Radio (NR) system is currently discussing the support of various numerologies for time-frequency resource unit standards, taking into account various scenarios, service requirements, potential system compatibility, etc.

[0004] 5G communication can support the transmission of physical signals or physical channels through multiple beams to overcome adverse channel conditions such as high path loss, phase noise, and frequency offset that occur at high carrier frequencies. This enables 5G communication to support applications such as enhanced Mobile Broadband (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communication (URLLC).

[0005] V2X communication, a communication method for exchanging or sharing information such as traffic conditions while communicating with road infrastructure and other vehicles while driving, can also be considered. V2X can include vehicle-to-vehicle (V2V), which refers to Long Term Evolution (LTE) / New Radio (NR)-based communication between vehicles, vehicle-to-pedestrian (V2P), which refers to LTE / NR-based communication between vehicles and personally carried devices, and vehicle-to-infrastructure / network (V2I / N), which refers to LTE / NR-based communication between vehicles and roadside units / networks. Here, roadside units (RSUs) can be transportation infrastructure entities implemented by base stations or fixed devices. For example, they can be entities that transmit speed notifications to vehicles. Summary of the Invention [Problem to be solved by the invention]

[0006] The technical problem of the present disclosure relates to a method and apparatus for performing sidelink (SL) communication in a wireless communication system.

[0007] The technical problem of the present disclosure relates to a method and apparatus for configuring an SL resource pool on an unlicensed band.

[0008] The technical problem of the present disclosure relates to a method and apparatus for configuring a SL resource pool on an unlicensed spectrum based on RBS (resource block set) and interlace / subchannel.

[0009] The technical problem of the present disclosure relates to a method and apparatus for transmitting a physical sidelink control channel (PSCCH) in an SL resource pool on an unlicensed band.

[0010] The technical problem of the present disclosure relates to a method and apparatus for allocating PSCCH resources in an SL resource pool on an unlicensed band.

[0011] The technical problems of this disclosure are: st SCI (sidelink control information) (hereinafter referred to as "1st SCI") and 2nd nd The present invention relates to a method and apparatus for allocating SCI (hereinafter referred to as "second SCI") resources.

[0012] The technical problem of the present disclosure relates to a method and apparatus for allocating PSCCH resources based on whether or not LBT (listen before talk) is successful in an RBS in an SL resource pool.

[0013] The technical problems to be solved by the present disclosure are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the following description. [Means for solving the problem]

[0014] A method for configuring a sidelink resource pool in a terminal in a wireless communication system according to one embodiment of the present disclosure may include the steps of: receiving resource pool configuration information from a base station based on higher layer signaling by the terminal; checking whether channel occupancy of at least one resource block set (RBS) in the resource pool is successful based on the resource pool configuration information; allocating physical sidelink control channel (PSCCH) resources in at least one RBS based on whether the channel occupancy is successful, and performing PSCCH transmission; and performing sidelink communication with another terminal.

[0015] Furthermore, according to one aspect of the present disclosure, when PSCCH resources are allocated in at least one or more RBSs that have successfully occupied the channel based on whether or not the channel occupation is successful, the PSCCH resources can be allocated only in any of the at least one or more RBSs that have successfully occupied the channel.

[0016] Furthermore, according to one aspect of the present disclosure, when PSCCH resources are allocated within at least one or more RBSs that have successfully occupied the channel based on whether or not the channel occupation is successful, the PSCCH resources can be allocated to each of the at least one or more RBSs that have successfully occupied the channel, and the PSCCH can be duplicated and allocated to each of the at least one or more RBSs that have successfully occupied the channel.

[0017] Furthermore, according to one aspect of the present disclosure, when PSCCH resources are allocated within at least one RBS, the PSCCH resources can be allocated to resources corresponding to a set number of consecutive interlaces from the lowest interlace RB included in the lowest subchannel within the RBS.

[0018] Furthermore, according to one aspect of the present disclosure, when PSCCH resources are allocated within at least one RBS, the PSCCH resources can be allocated to resources corresponding to a non-consecutive number of interlaces set from the lowest interlace RB included in the lowest subchannel within the RBS. [Effects of the Invention]

[0019] According to the present disclosure, a method for performing sidelink (SL) communication in a wireless communication system can be provided.

[0020] According to the present disclosure, a method for configuring a SL resource pool on an unlicensed band can be provided.

[0021] According to the present disclosure, a method for configuring a SL resource pool on an unlicensed spectrum based on a resource block set (RBS) and an interlace / subchannel can be provided.

[0022] According to the present disclosure, it is possible to provide a method for transmitting a physical sidelink control channel (PSCCH) in an SL resource pool on an unlicensed band.

[0023] According to the present disclosure, a method for allocating PSCCH resources in an SL resource pool on an unlicensed spectrum can be provided.

[0024] According to the present disclosure, a method for allocating first sidelink control information (SCI) and second SCI resources can be provided.

[0025] According to the present disclosure, it is possible to provide a method for allocating PSCCH resources based on whether or not an LBT (listen before talk) is successful in an RBS in an SL resource pool.

[0026] The effects obtained by the present disclosure are not limited to the effects described above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present disclosure pertains from the following description. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a diagram for explaining an NR frame structure to which the present disclosure can be applied. [Figure 2] FIG. 2 is a diagram illustrating an NR resource structure to which the present disclosure may be applied. [Figure 3] FIG. 3 is a diagram illustrating an NR sidelink slot structure to which the present disclosure can be applied. [Figure 4] FIG. 4 is a diagram illustrating NR sidelink frequencies to which the present disclosure can be applied. [Figure 5] FIG. 5 is a diagram illustrating an NR sidelink resource pool configuration to which the present disclosure can be applied. [Figure 6] FIG. 6 is a diagram illustrating unlicensed bands by region for NR sidelink communication to which the present disclosure can be applied. [Figure 7] FIG. 7 is a diagram illustrating 5 GHz unlicensed band usage to which the present disclosure may be applied. [Figure 8] FIG. 8 illustrates a method for increasing bandwidth taking into account PSD limitations to which the present disclosure may be applied. [Figure 9] FIG. 9 is a diagram showing a method for setting a guard band in consideration of a shared band within an intra-cell to which the present disclosure can be applied. [Figure 10] FIG. 10 is a diagram illustrating an interlace-based RB resource allocation method to which the present disclosure can be applied. [Figure 11] FIG. 11 is a diagram illustrating a method for performing a listen before talk (LBT) procedure in an unlicensed spectrum to which the present disclosure may be applied. [Figure 12] FIG. 12 is a diagram illustrating COT sharing and discovery burst transmission to which the present disclosure can be applied. [Figure 13]FIG. 13 is a diagram illustrating a method for applying a CP extension to an uplink when performing COT sharing between a downlink and an uplink to which the present disclosure may be applied. [Figure 14] FIG. 14 is a diagram illustrating a semi-static channel connection procedure to which the present disclosure can be applied. [Figure 15] FIG. 15 is a diagram illustrating a method for performing channel occupation to which the present disclosure may be applied. [Figure 16] FIG. 16 illustrates a method for configuring RBS with BWP and resource pool in a sidelink unlicensed band to which the present disclosure may be applied. [Figure 17] FIG. 17 is a diagram illustrating time and frequency resources of a PSCCH to which the present disclosure can be applied. [Figure 18] FIG. 18 illustrates a method for allocating PSCCH resources in adjacent RBSs to which the present disclosure may be applied. [Figure 19] FIG. 19 illustrates a method for allocating PSCCH resources in adjacent RBSs to which the present disclosure may be applied. [Figure 20] FIG. 20 is a diagram showing a case where a plurality of RBSs are set in one resource pool to which the present disclosure can be applied. [Figure 21] FIG. 21 is a diagram showing a case where multiple RBSs are set in a resource pool to which the present disclosure can be applied. [Figure 22] FIG. 22 is a diagram showing a case where multiple RBSs are set in a resource pool to which the present disclosure can be applied. [Figure 23] FIG. 23 is a diagram showing a case where multiple RBSs are set in a resource pool to which the present disclosure can be applied. [Figure 24] FIG. 24 is a diagram showing a case where multiple RBSs are set in a resource pool to which the present disclosure can be applied. [Figure 25] FIG. 25 illustrates a method for allocating PSCCH RBs based on the interlaces associated within a subchannel to which the present disclosure may be applied. [Figure 26]FIG. 26 illustrates a method for allocating PSCCH RBs based on the interlaces associated within a subchannel to which the present disclosure may be applied. [Figure 27] FIG. 27 is a diagram illustrating an SL channel to which the present disclosure can be applied. [Figure 28] FIG. 28 is a diagram illustrating a second SCI resource allocation method to which the present disclosure can be applied. [Figure 29] FIG. 29 is a diagram illustrating a second SCI resource allocation method to which the present disclosure can be applied. [Figure 30] FIG. 30 is a diagram illustrating a second SCI resource allocation method to which the present disclosure can be applied. [Figure 31] FIG. 31 is a diagram illustrating a method for allocating a second SCI to which the present disclosure can be applied. [Figure 32] FIG. 32 is a diagram illustrating a method for allocating a second SCI based on a plurality of subchannels to which the present disclosure can be applied. [Figure 33] FIG. 33 is a flowchart illustrating a PSCCH resource allocation method to which the present disclosure can be applied. [Figure 34] FIG. 34 is a flowchart illustrating a PSCCH resource allocation method to which the present disclosure can be applied. [Figure 35] FIG. 35 is a diagram showing a base station apparatus and a terminal apparatus to which the present disclosure can be applied. DETAILED DESCRIPTION OF THE INVENTION

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present disclosure will be described in detail below with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be embodied in various different forms and is not limited to the embodiments described herein.

[0029] In describing embodiments of the present disclosure, if it is determined that a detailed description of a known configuration or function would obscure the gist of the present disclosure, the detailed description will be omitted. In addition, in the drawings, parts that are not related to the description of the present disclosure will be omitted, and similar parts will be designated by similar reference numerals.

[0030] In this disclosure, when a component is said to be "coupled," "coupled," or "connected" to another component, this refers not only to a direct connection, but also to an indirect connection where there is another component between them. Furthermore, when a component is said to "include" or "have" another component, this does not exclude the other component, but means that the component may further include the other component, unless otherwise specified.

[0031] In this disclosure, terms such as first and second are used only to distinguish one component from another, and do not limit the order or importance of the components unless otherwise specified. Therefore, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0032] In this disclosure, components that are distinguished from one another are used to clearly describe the characteristics of each component and do not necessarily mean that the components are separate. That is, multiple components may be integrated into a single hardware or software unit, or a single component may be distributed into multiple hardware or software units. Therefore, even if not otherwise specified, such integrated or distributed embodiments are also included within the scope of this disclosure.

[0033] In this disclosure, the components described in various embodiments are not necessarily essential components, and some may be optional components. Therefore, an embodiment consisting of a subset of the components described in one embodiment is also included in the scope of this disclosure. Note that an embodiment including other components in addition to the components described in various embodiments is also included in the scope of this disclosure.

[0034] The present disclosure describes a wireless communication network, and operations performed in the wireless communication network may be performed in a process of controlling the network and transmitting or receiving signals by a system (e.g., a base station) that manages the wireless communication network, or in a process of transmitting or receiving signals by a terminal coupled to the wireless network.

[0035] It is apparent that various operations performed for communication with a terminal in a network consisting of multiple network nodes including a base station may be performed by the base station or other network nodes other than the base station. The term "base station (BS)" may be replaced with terms such as fixed station, Node B, eNodeB (eNB), ng-eNB, gNodeB (gNB), access point (AP), etc. Furthermore, the term "terminal" may be replaced with terms such as user equipment (UE), mobile station (MS), mobile subscriber station (MSS), subscriber station (SS), non-AP station (non-AP STA), etc.

[0036] In this disclosure, transmitting or receiving a channel includes transmitting or receiving information or signals through the channel. For example, transmitting a control channel means transmitting control information or signals through the control channel. Similarly, transmitting a data channel means transmitting data information or signals through the data channel.

[0037] In the following description, the term NR (New Radio) system is used to distinguish the system to which various examples of the present disclosure are applied from existing systems, but the scope of the present disclosure is not limited by these terms.

[0038] The NR system supports various subcarrier spacings (SCS) taking into account various scenarios, service requirements, and potential system compatibility. The NR system can also support the transmission of physical signals / channels through multiple beams to overcome adverse channel conditions such as high path loss, phase noise, and frequency offset that occur at high carrier frequencies. This allows the NR system to support applications such as enhanced Mobile Broadband (eMBB), massive Machine Type Communications (mMTC) / ultra Machine Type Communications (uMTC), and Ultra Reliable and Low Latency Communications (URLLC).

[0039] Hereinafter, 5G mobile communication technology may be defined to include not only the NR system but also the existing LTE-A (Long Term Evolution-Advanced) and LTE (Long Term Evolution) systems. That is, 5G communication may include not only the newly defined NR system but also technologies that operate in consideration of backward compatibility with previous systems. Therefore, the 5G mobile communication described below may include technologies that operate based on the NR system and technologies that operate based on previous systems (e.g., LTE-A, LTE), and is not limited to a specific system.

[0040] First, a brief description will be given of the physical resource structure of the NR system to which the present invention is applied.

[0041] FIG. 1 is a diagram for explaining an NR frame structure to which the present disclosure can be applied.

[0042] The basic unit of time domain in NR is T c =1 / (Δf max N f ) and Δf max =480 10 3 and N f = 4096, whereas the time domain base unit in LTE is Ts = 1 / (Δf ref N f,ref ) and Δf ref =15 10 3 and N f,ref = 2048. The constant for the multiple relationship between the base unit of NR time and the base unit of LTE time is κ = T s / T c =64.

[0043] Referring to FIG. 1, the time structure of a frame for downlink / uplink (DL / UL) transmission is T f =(Δf max N f / 100)·T s = 10 ms, where one frame is T sf =(Δf max N f / 1000)·T s The number of consecutive OFDM symbols in each subframe is N subframe,u symb =N slot symb N subframe,u slot Also, each frame can be divided into two half frames of the same size, with half frame 1 consisting of subframes 0 to 4 and half frame 2 consisting of subframes 5 to 9.

[0044] N TA denotes the timing advance (TA) between the downlink (DL) and the uplink (UL), where the transmission timing of the uplink transmission frame i is determined based on the downlink reception timing at the terminal according to the following Equation 1:

[0045]

number

[0046] where N TA,offset is the TA offset value that occurs due to differences in duplex modes. TA,offset has a value of 0, but in TDD (Time Division Duplex), N is set to N in consideration of the margin for DL-UL switching time. TA,offset For example, in TDD (Time Division Duplex) in FR1 (Frequency Range 1), which is a frequency below 6 GHz, N TA,offset is 39936T C or 25600T C It can be. 39936T C is 20.327μs, and 25600T C is 13.030μs. Also, at the millimeter wave (mmWave) frequency FR2 (Frequency Range 2), N TA,offset is 13792T C At this time, 39936T C is 7.020μs.

[0047] FIG. 2 is a diagram illustrating an NR resource structure to which the present disclosure may be applied.

[0048] The resource elements (REs) in the resource grid can be indexed by each subcarrier spacing, where one resource grid can be generated for each antenna port and each subcarrier spacing, and uplink and downlink transmission and reception can be performed based on the resource grid.

[0049] In the frequency domain, one resource block (RB) consists of 12 REs, and an index (n PRB ) can be configured. The index for the RB can be used within a specific frequency band or system bandwidth. The index for the RB can be defined as in Equation 2 below. Here, N RB sc denotes the number of subcarriers per RB, and k denotes the subcarrier index.

[0050]

number

[0051] Various neural networks can be configured to meet the various services and requirements of the NR system. For example, an LTE / LTE-A system can support one subcarrier spacing (SCS), while an NR system can support multiple SCSs.

[0052] New pneumatics for NR systems supporting multiple SCSs can operate in frequency ranges or carriers such as below 3 GHz, 3 GHz to 6 GHz, 6 GHz to 52.6 GHz, or above 52.6 GHz, solving the problem of not being able to use wide bandwidths in frequency ranges or carriers such as 700 MHz or 2 GHz.

[0053] Table 1 below shows examples of pneumoradio supported by the NR system.

[0054] [Table 1]

[0055] Referring to Table 1, the neural network parameters can be defined based on the subcarrier spacing (SCS), cyclic prefix (CP) length, and number of OFDM symbols per slot used in an Orthogonal Frequency Division Multiplexing (OFDM) system. These values can be provided to the UE through upper layer parameters DL-BWP-mu and DL-BWP-cp for the downlink and through upper layer parameters UL-BWP-mu and UL-BWP-cp for the uplink.

[0056] In Table 1, when the subcarrier spacing setting index (u) is 2, the subcarrier spacing (Δf) is 60 kHz, and normal CP and extended CP can be applied. In other cases, only normal CP can be applied.

[0057] A normal slot can be defined as a basic time unit used to transmit one piece of data and control information in an NR system. The length of a normal slot can be basically set to 14 OFDM symbols. Furthermore, unlike a slot, a subframe has an absolute time length corresponding to 1 ms in an NR system and can be used as a reference time for the length of other time intervals. Here, for coexistence or backward compatibility between LTE and NR systems, a time interval similar to an LTE subframe may be required in the NR standard.

[0058] For example, in LTE, data may be transmitted based on a transmission time interval (TTI), which is a unit of time, and the TTI may be set in units of one or more subframes. Here, in LTE, one subframe may be set to 1 ms and may include 14 OFDM symbols (or 12 OFDM symbols).

[0059] Furthermore, non-slots can be defined in NR. A non-slot may refer to a slot having a number of symbols at least one smaller than that of a normal slot. For example, when providing low latency, such as in a URLLC service, the latency can be reduced by using a non-slot having a number of symbols smaller than that of a normal slot. Here, the number of OFDM symbols included in a non-slot can be determined taking into account the frequency range. For example, in a frequency range of 6 GHz or higher, a non-slot having a length of one OFDM symbol can be considered. As a further example, the number of OFDM symbols defining a non-slot can include at least two OFDM symbols. Here, the range of the number of OFDM symbols included in a non-slot can be set as the length of a mini-slot up to a predetermined length (e.g., the normal slot length minus 1). However, as a non-slot standard, the number of OFDM symbols may be limited to, but not limited to, 2, 4, or 7 symbols.

[0060] For example, in unlicensed bands below 6 GHz, subcarrier spacing where u is 1 and 2 can be used, and in unlicensed bands above 6 GHz, subcarrier spacing where u is 3 and 4 can be used. For example, when u is 4, it can be used for SSB (Synchronization Signal Block).

[0061] [Table 2]

[0062] Table 2 shows the number of OFDM symbols per slot (N) for normal CP, depending on the subcarrier spacing setting (u). slot symb ), number of slots per frame (N frame,u slot ), the number of slots per subframe (N subframe,u slot) Table 2 shows the above values based on a normal slot having 14 OFDM symbols.

[0063] [Table 3]

[0064] Table 3 shows the number of slots per frame and the number of slots per subframe when extended CP is applied (i.e., when u is 2 and the subcarrier spacing is 60 kHz), based on a normal slot with 12 OFDM symbols per slot.

[0065] As mentioned above, one subframe may correspond to 1 ms on the time axis. Furthermore, one slot may correspond to 14 symbols on the time axis. For example, one slot may correspond to 7 symbols on the time axis. Therefore, the number of slots and symbols that can be considered within 10 ms, which corresponds to one radio frame, can be set differently. Table 4 shows the number of slots and symbols according to each SCS. In Table 4, the 480 kHz SCS may not be considered, but is not limited to these examples.

[0066] [Table 4]

[0067] V2X services (e.g., LTE Rel-14 V2X) can support basic requirements for V2X services. The requirements are primarily designed with road safety services in mind. Here, V2X User Equipment (UE) can exchange status information with each other through sidelink. Furthermore, V2X UE can exchange information with infrastructure nodes and / or pedestrians.

[0068] V2X services (e.g., LTE Rel-15) can support at least one of carrier aggregation, high order modulation, latency reduction, transmit diversity, and sTTI (Transmission Time Interval) in the sidelink. This allows new features to be applied to V2X communication. Specifically, V2X UEs can operate while taking into account coexistence with other V2X UEs. For example, V2X UEs can use the same resource pool as other V2X UEs.

[0069] As an example, considering use cases for supporting V2X services in SA (System Aspect) 1, technical features can be classified into four categories as shown in Table 5 below, but are not limited to these. In Table 5, Vehicle Platooning can be a technology in which multiple vehicles dynamically form a group and operate in a similar manner. Extended Sensors can be a technology that collects and exchanges data obtained from sensors or video footage. Advanced Driving can be a technology in which vehicles drive based on full automation or semi-automation. Remote Driving can be a technology that provides technology and applications for remote control of vehicles, and more specific details of the above can be seen in Table 5 below.

[0070] [Table 5]

[0071] Furthermore, SA1 is an eV2X (enhanced V2X) support technology for supporting V2X services and can support cases where it operates in various systems (e.g., LTE, NR). As an example, a case can be considered in which the NR V2X system is a first V2X system and the LTE V2X system is a second V2X system. That is, the NR V2X system and the LTE V2X system can be different V2X systems.

[0072] Hereinafter, a method for achieving low latency and high reliability required for an NR sidelink will be described based on an NR V2X system. However, the same or similar configuration may be extended and applied to an LTE V2X system, and the present invention is not limited to the following embodiments. That is, the present invention may be applied to parts that are interoperable with an LTE V2X system.

[0073] Here, NR V2X capability is not necessarily limited to supporting only V2X services, and may optionally support the use of a certain V2X RAT.

[0074] Additionally, NR V2X services can additionally consider new service requirements for public safety and commercial use cases. For example, use cases may include, but are not limited to, at least one of more advanced V2X services, public safety services, NCIS (Network Controlled Interactive Service), MONASTERYEND (Gap Analysis for Railways), REFEC (Enhanced Relays for Energy eFficiency and Extensive Coverage), and AVPROD (Audio-Visual Service Production).

[0075] For the NR V2X, physical channels, signals, a basic slot structure, and physical resources can be configured. Here, the NR Physical Sidelink Shared Channel (NR PSSCH) can be a physical layer NR Sidelink (SL) data channel. V2X terminals can exchange data and control information (e.g., 2nd SCI, CSI) through the NR PSSCH. The NR Physical Sidelink Control Channel (NR PSCCH) is a physical layer NR SL control channel. The NR PSCCH is a channel for transmitting control information (1st SCI, Sidelink Control Information) including scheduling information for the NR SL data channel and a 2nd SCI indication. That is, a V2X terminal can transmit control information for sidelink data communication to another V2X terminal through the PSCCH. The NR Physical Sidelink Feedback Channel (NR PSFCH) is a channel for transmitting physical layer NR Hybrid Automatic Repeat Request (HARQ) feedback information and for transmitting HARQ-ACK feedback information corresponding to the NR SL data channel (i.e., PSSCH). After transmitting data to another V2X terminal, a V2X terminal can receive HARQ feedback information for the data via the NR PSFCH. The NR Sidelink Synchronization Signal / Physical Sidelink Broadcast Channel block (SLSS / PSBCH block) is a channel block in which an NR sidelink synchronization signal and a broadcast channel are transmitted over a continuous time period in the physical layer. Here, the SLSS / PSBCH block may be transmitted periodically based on a set of one or more block indexes to support beam-based transmission in the NR frequency band.The synchronization signal consists of a Primary Sidelink Synchronization Signal (PSSS) and a Secondary Sidelink Synchronization Signal (SSSS). The synchronization signal is generated in a sequence based on at least one SLSSID value. The NR Physical Sidelink Broadcast Channel (PSBCH) is a channel that carries system information required for V2X sidelink communication. The NR PSBCH is transmitted together with the SLSS and is periodically transmitted in the form of an aggregate of the SLSS / PSBCH block index to support beam-based transmission.

[0076] In addition, a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH) can be defined based on NR V2X. A terminal can transmit sidelink control information (SCI) to another terminal through the PSCCH. Here, a transmitting terminal can transmit a primary SCI (1st SCI, SCI format 1-A) to a receiving terminal through the PSSCH. In this case, the primary SCI can be used to schedule the PSSCH and the secondary SCI (2nd SCI) within the PSSCH, and the primary SCI can include at least one of priority information, time / frequency resource allocation information, resource reservation information, Demodulation Reference Signal (DMRS) pattern information, secondary SCI format indication information, beta-offset indicator information as a parameter for the secondary SCI and PSSCH rate matching operation, DMRS port number information, MCS (Modulation Coding Scheme) information, additional MCS table indicator information (e.g., indicating one of 64QAM, 256QAM, or URLLC MCS tables), PSFCH overhead indication information (a parameter for the 2nd SCI and PSSCH rate matching operation), and reserved bits.

[0077] FIG. 3 is a diagram illustrating an NR sidelink slot structure to which the present disclosure can be applied.

[0078] Referring to FIG. 3, one sidelink slot (SL slot) includes one automatic gain control (AGC) symbol. One SL slot also includes one transmit-receive (Tx-Rx) switching symbol. In one SL slot, the PSSCH, which is a channel for transmitting data, is transmitted through one or more subchannels (e.g., two subchannels in the case of FIG. 3). In addition, in the time domain, the remaining orthogonal frequency division multiplexing (OFDM) symbols, excluding the AGC symbol and the Tx-Rx switching symbol, may transmit the PSCCH (1st SCI), the secondary SCI, the PSSCH (Data), and a demodulation RS (DMRS) for demodulation. Specifically, the positions of the PSCCH (1st SCI), the secondary SCI, the PSSCH (Data), and the DMRS (Demodulation RS) for demodulation are as shown in FIG. 3, but are not limited thereto. For example, in Fig. 3, the first subchannel has a PSCCH and a secondary SCI, and the PSSCH and DMRS can be allocated taking this into consideration. As another example, the second subchannel in Fig. 3 is a subchannel without a PSCCH or a secondary SCI, and the PSSCH and DMRS can be allocated as shown in Fig. 3.

[0079] Here, the number of OFDMs for the PSSCH DMRS can be set to one or more depending on the channel environment of the terminal through higher layer configuration. The PSCCH (1st SCI) is decoded and received using the DMRS of the PSCCH (i.e., the PSCCH DMRS) and is transmitted by being evenly allocated to every four resource elements within one resource block (RB). On the other hand, the 2nd SCI is decoded using the PSSCH DMRS.

[0080] For example, one resource pool related to the NR sidelink can support all of frequency division multiplexing (FDM), time division multiplexing (TDM), and spatial division multiplexing (SDM). That is, each resource in one resource pool can be divided and used based on frequency, time, and space, thereby improving resource efficiency.

[0081] 4 is a diagram illustrating NR sidelink frequencies to which the present disclosure can be applied. For example, the NR sidelink can operate based on at least one of FR1 (Frequency Range 1, sub 6 GHz) and FR2 (Frequency Range 2, i.e., up to 52.6 GHz), unlicensed ITS bands, and licensed bands. As a specific example, referring to FIG. 4, 5,855 to 5,925 MHz can be allocated for ITS services (technology neutral manner).

[0082] Furthermore, NR V2X Quality of Service (QoS) requirements can be considered. That is, as requirements for NR V2X services, delay, reliability, and data rate must meet certain conditions. Here, the requirements can be set as shown in Table 6 below, and Table 7 can be a table showing PC5 QoS for NR V2X.

[0083] Here, to meet QoS requirements, access stratum (AS)-level QoS management may be necessary. For this purpose, HARQ and CSI feedback associated with link adaptation may be required. Furthermore, each NR V2X UE may have a different maximum bandwidth capability. In consideration of the above, NR V2X UEs may exchange AS-level information including at least one of UE capability, QoS-related information, radio bearer configuration, and physical layer configuration.

[0084] [Table 6]

[0085] [Table 7-1] [Table 7-2] [Table 7-3]

[0086] NOTE 1: For the standardized PQI to QoS characteristic mapping, the table will be extended or updated to support service requirements for other specific V2X services. (NOTE 1: For Standardized PQI to QoS characteristics mapping, the table will be extended / updated to support service requirements for other identified V2X services.)

[0087] Note 2: PQI can also be used for services other than V2X. (NOTE 2: The PQIs may be used for other services than V2X.)

[0088] Next, the sidelink HARQ procedure will be described. Whether a V2X terminal reports HARQ feedback is indicated by higher layer (e.g., RRC) configuration and SCI signaling (e.g., 2nd SCI). For example, when a V2X terminal performs communication based on groupcast, it can determine whether to report HARQ feedback based on the distance between the transmitting terminal and the receiving terminal.

[0089] When a V2X terminal performs unicast and / or groupcast, it may enable or disable sidelink HARQ feedback, where the enable / disable of HARQ feedback may be determined based on at least one of channel conditions (e.g., RSRP), the distance between the transmitting terminal and the receiving terminal, and QoS requirements.

[0090] In the case of groupcast, whether to transmit HARQ feedback can be determined depending on the physical distance between the transmitting terminal and the receiving terminal. Here, when HARQ feedback is performed based on groupcast, the receiving terminal can operate to feed back a negative acknowledgment only when PSSCH decoding fails. This can be the operation of option 1. On the other hand, when HARQ feedback is performed based on groupcast, the receiving terminal can operate to feed back a positive or negative acknowledgment depending on whether PSSCH decoding is successful, which can be the operation of option 2. In the operation of option 1, which feeds back only a negative acknowledgment to the HARQ NACK based on groupcast, feedback for the PSSCH can be performed if the physical distance between the transmitting terminal and the receiving terminal is smaller than or equal to the communication range requirement. On the other hand, if the physical distance between the transmitting terminal and the receiving terminal is larger than the communication range requirement, the V2X terminal does not need to feed back PSSCH.

[0091] At this time, the location of the transmitting terminal is indicated to the receiving terminal through the SCI associated with the PSSCH. The receiving terminal can estimate the distance to the transmitting terminal based on the information included in the SCI and its own location information and operate as described above.

[0092] In addition, when performing unicast communication based on V2X, the case where sidelink HARQ feedback is enabled can be taken into consideration. The receiving terminal can generate and transmit HARQ ACK / NACK for PSSCH based on whether the corresponding TB (Transport Block) has been successfully decoded.

[0093] Next, the NR sidelink resource allocation mode includes a mode in which the base station schedules sidelink transmission resources. Here, the mode in which the base station schedules sidelink transmission resources may be Mode 1. For example, when a V2X terminal is located within the base station coverage, the V2X terminal may receive sidelink resource information from the base station based on Mode 1. On the other hand, there is also a mode in which the V2X terminal directly determines resources for sidelink transmission from sidelink resources configured by the base station / network or pre-configured sidelink resources. Here, the mode in which the terminal directly determines sidelink transmission resources may be Mode 2.

[0094] Also, the numerology and waveform for the sidelink may be considered, and may be as shown in Table 8 below. Specifically, in relation to the PSSCH / PSCCH and PSFCH in the sidelink, the SCS and CP lengths supported by each of FR1 and FR2 may be as shown in Table 8 below. Here, the waveform may not support DFT-S-OFDM and may support only OFDM, but is not limited thereto. A sidelink-synchronization signal block (SL-SSB) may be defined independently for each frequency range, which may be similar to NR-Uu.

[0095] [Table 8]

[0096] FIG. 5 is a diagram illustrating an NR sidelink resource pool configuration to which the present disclosure can be applied. Referring to FIG. 5, a resource pool may refer to time and frequency resources used for sidelink transmission and reception. As an example, at least one resource pool may be configured within one SL BWP within one carrier. Here, the resources of the resource pool may be configured based on time resources in units of slot sets and frequency resources in units of consecutive subchannel sets. Furthermore, the resource pool may be configured separately for transmission and reception.

[0097] More specifically, the time resource for resource pool configuration provided in the NR sidelink is the time period of the resource pool, a set of sidelink slots (sl-TimeResource(length=L bitmap)), the first symbol for a set of consecutive symbols within one slot, and / or the number of consecutive symbols may be configured. The frequency resource may be configured as at least one of the bandwidth of one subchannel (e.g., sl-SubchannelSize={10, 15, 20, 25, 50, 75, and 100} RBs), the total bandwidth of a resource pool indicated by the number of consecutive subchannels (a set of consecutive subchannels (e.g., sl-NumSubchannel={1 to 27}), and the frequency domain position of the first subchannel of the resource pool (sl-StartRBsubchannel={0 to 265}). For example, resources in the time domain and the frequency domain may be configured based on higher layer parameters. In FIG. 5, the frequency resource corresponding to the excluded resource block (RB) may refer to some RBs remaining when the total available RB resources do not exactly match the subchannel size (i.e., when the number of RBs does not match one subchannel). In this case, the resource may not be used in the NR sidelink. Also, for example, reserved slots (reserved slots) may be configured. The sl-slot) can refer to the remaining slots when the length of the bitmap on the time resource (e.g., sl-TimeResource) is not a multiple of the length, and does not need to be used as an NR sidelink resource.

[0098] Next, a case where an unlicensed spectrum is used for communication between a base station and a terminal may be considered. For example, a communication scheme based on an unlicensed spectrum may occupy a channel through contention and perform communication based on the occupied channel. Communication based on an unlicensed spectrum may also be performed between a base station and a terminal. Hereinafter, an operation based on a case where an unlicensed spectrum is used for sidelink communication will be described. That is, an unlicensed spectrum may also be used in sidelink communication, which is communication between terminals. Furthermore, a sidelink resource pool needs to be configured taking into account the use of a sidelink unlicensed spectrum. More specifically, sidelink communication may be performed based on a resource pool, and if communication is performed through an unlicensed spectrum, the resource pool configuration needs to be different.

[0099] For example, the resource pool for sidelink communication may be configured on a slot-by-slot basis to determine symbols available for sidelink within a slot, as shown in Figure 5. In addition, in the frequency domain, the resource pool may be configured based on the number of consecutive subchannels, as shown in Figure 5. The sidelink resource pool configuration may be performed taking into account unlicensed band communication, as will be described later.

[0100] 6 is a diagram illustrating unlicensed bands by region for NR sidelink communication to which the present disclosure can be applied. In Table 8 above, the frequency range of R FR1 may be 450 MHz to 6 GHz, but the corresponding frequency range may be changed to 450 MHz to 7.125 GHz. The NR FR1 frequency range may be changed for the unlicensed band in the 6 GHz band, but is not limited to this.

[0101] By way of example, and without limitation, the unlicensed bands may be located below 1 GHz, 2.4 GHz, 5 GHz, 6 GHz, 37 GHz (US only), and 60 GHz. Referring to Figure 6, for example, the 5 GHz band in the system may be Band 46, defined as 5150-5925 MHz. Furthermore, by way of example, and without limitation, Band 49 (3550-3700 MHz) may be defined as a CBRS (citizens broadband radio service) band for LAA operations.

[0102] Figure 7 is a diagram illustrating the use of the 5 GHz unlicensed band to which the present disclosure can be applied. Referring to Figure 7, each band within the 5 GHz unlicensed band can be set, and the use of the unlicensed band can be set based on that band. For example, the bands can be divided into 20 MHz units for use, and each 20 MHz can be one channel.

[0103] In most areas, the low frequency band from 5150 to 5350 MHz is intended for indoor use and is regulated to have a maximum transmission power of 23 dBm. In the band above 5470 MHz, a transmission power of up to 30 dBm is permitted for outdoor use. In addition to the maximum transmission power limit, some areas may have additional requirements, such as the EIRP (effective isotropic radiated power) value shown in Table 9 below.

[0104] [Table 9]

[0105] Here, PSD (power spectral density) can mean that a device is limited to transmitting at full power within a reference bandwidth. As a specific example, European regulations may limit PSD to 10 dBm / MHz. Therefore, if the bandwidth is not 20 MHz, a device cannot transmit at a maximum transmission power of 23 dBm.

[0106] 8 is a diagram illustrating a method for increasing bandwidth in consideration of PSD limitations to which the present disclosure may be applied. As an example, consider the case of small data transmission, which requires only a small bandwidth, as shown in FIG. 8. In this case, if small data transmission is performed over a wide bandwidth, coverage can be expanded. Furthermore, transmission over a wide bandwidth can satisfy minimum bandwidth occupancy regulations. In consideration of the above, a method for transmitting small data over a wide bandwidth may be preferable.

[0107] For example, when a channel is occupied through a channel access procedure in an unlicensed band, the maximum channel occupancy time (COT), which corresponds to the maximum time that a channel can be occupied, can be set differently for each region. For example, Japan allows a maximum COT of 4 ms, while Europe allows a maximum COT of 8 ms or 10 ms. However, this is merely an example and is not limited to the above-described embodiment. For example, Europe can support Frame Based Equipment (FBE) and Load Based Equipment (LBE) rules. Here, FBE is set to High Performance Radio LAN (HiperLAN) / 2, and LBE can be adopted and applied in the Wi-Fi standard, and both can be supported in NR as a new communication system.

[0108] Further, as an example, the minimum occupied bandwidth may be a specification of a bandwidth that must be minimally occupied once a channel connection is successful. For example, the specification of the minimum occupied bandwidth may be set to occupy 80 to 90% or more of the nominal channel BW. As a specific example, when a terminal transmits a PUSCH to a base station in an unlicensed band, it may request that resources for the PUSCH be allocated to the entire band in an interlaced form with a specific bandwidth, but this may not be limited to this embodiment.

[0109] Furthermore, the dynamic frequency selection provision may be a provision to limit bandwidth usage in order to protect systems (e.g., radio) that have a high priority for using unlicensed bands. Furthermore, the transmit power control provision may be a provision to limit the use of transmit power lower than the maximum permitted transmit power value. Furthermore, the LBT (listen before talk) provision is a provision regarding procedures for channel access, and Europe can support FBE and LBE rules. At this time, FBE is Hiperlan / 2, and LBE can be adopted and applied in Wi-Fi standards, and both can be supported in NR.

[0110] For example, the 5 GHz unlicensed band can be used based on the above, but discussions regarding the use of the 6 GHz band are underway among various countries and organizations. Unlike the 5 GHz band, the 6 GHz band may be a band that has not yet been used by a mobile system. That is, unlike the 5 GHz band, which is shared by multiple mobile communication systems, the 6 GHz band can be used for a single, specific communication system. This reduces the problems and inefficiencies that arise from the coexistence of multiple different systems.

[0111] FIG. 9 is a diagram showing a method for setting a guard band in consideration of a shared band (e.g., an unlicensed band) within an intra-cell to which the present disclosure can be applied.

[0112] Referring to FIG. 9, to support wideband operation in shared spectrum access, the UE may receive an IntraCellGuardBandsPerSCS parameter for each of the uplink carrier (UL carrier) and the downlink carrier (DL carrier) from the base station based on the base station configuration. The UE may receive the IntraCellGuardBandsPerSCS parameter for each of the uplink carrier (UL carrier) and the downlink carrier (DL carrier) from the base station based on the base station configuration. 9, the UE may be provided with an intra-cell guard band of JPEG2025526036000015.jpg936. Referring to FIG. 9, the UE may be provided with higher layer signaling regarding the starting common resource block (CRB) for each guard band and the size of the number of CRBs. For example, a CRB may be a resource block defined / set based on point A, which is the starting point of the transmission bandwidth on a carrier in the frequency domain. The UE may check information regarding point A through base station signaling and, based on the information, recognize the CRB position in the frequency domain. Here, each guard band is provided with a starting CRB. JPEG2025526036000016.jpg1326 is defined based on the parameters, and the size of the number of CRBs in each guard band is The UE may be provided with the above information through higher layer signaling based on the startCRB and nrofCRBs parameters, respectively. JPEG2025526036000018.jpg972, JPEG2025526036000019.jpg928 is the number of RB sets, and x may be set to DL or UL for downlink and uplink. The 928RB set may be configured as a resource block set (RBS) within one carrier through guard band configuration. For example, the guard band may be configured based on the IntraCellGuardBandsPerSCS parameter, thereby configuring an RBS within one carrier.

[0113] Here, each RBS frequency bandwidth may correspond to an LBT frequency bandwidth. That is, each RBS may be set to a bandwidth corresponding to an LBT procedure performed between a base station and a terminal. For example, in FIG. 9, RB set 1 (911) and RB set 2 (922) correspond to an LBT bandwidth, and if LBT is successful in that area, the band can be occupied to perform communication. That is, an RBS may correspond to an LBT bandwidth. For example, a transmitting node (e.g., a gNB or UE) can determine channel occupancy for an unlicensed band through an LBT channel access procedure performed on RBS resources corresponding to an LTE bandwidth. If the LBT procedure on one RBS is successful, the transmitting node can transmit on resources corresponding to that RBS.

[0114] Here, each RBS can be defined as a start CRB and an end CRB. The start CRB is JPEG2025526036000021.jpg1326 and the end CRB is JPEG2025526036000022.jpg1320. Here, the size of the guard band 913 may be nrofCRBs. As an example, the size of the guard band 913, nrofCRB, is determined by the subcarrier spacing μ and the carrier size It is not necessary to expect the size to be set to be smaller than the number of applicable intracell guard bands defined taking into consideration requirements regarding whether or not JPEG2025526036000023.jpg1322 will interfere with the wireless bandwidth.

[0115] At this time, the start CRB and the end CRB for each RBS 911, 912 can be determined based on the RBS index s, and the RBS index s is JPEG2025526036000024.jpg971. That is, the RBS index s is JPEG2025526036000025.jpg1323 may be a resource block having a size of JPEG2025526036000026.jpg1323 is the number of CRBs determined through the start CRB and end CRB based on the following Equation 3. Also, the start CRB and end CRB for each RBS may be as shown in Equation 4 and Equation 5.

[0116]

number

[0117]

number

[0118]

number

[0119] For example, if the UE is not provided with the IntraCellGuardBandsPerSCS parameter setting, the μ and carrier size of the carrier The CRB index for the nominal intra-cell guard band and RBS pattern based on JPEG2025526036000030.jpg1321 can be determined according to the requirements of the RF standard. Also, as an example, if the nominal intra-cell guard band and RBS pattern do not include the intra-cell guard band, the RBS of the corresponding carrier can be assumed to be 1.

[0120] For example, in FIG. 9, two LBT BWs (RBS0, RBS1) may be configured within one BWP 922 within one carrier bandwidth. In this case, one guard band 913 may be configured between the two RBSs 911, 913. The positions of the two RBSs 911, 913 may be determined as shown in FIG. 9 based on the above-mentioned higher layer parameters. Also, for example, when multiple BWPs 921, 923 are configured within one carrier bandwidth, the RBS associated with each BWP may be identified. Here, the RBSs corresponding to the first RBS (=s0, 912) and the last RBS (=s1, 911) of each BWP among the RBSs 911, 912 within the carrier may be indexed using the s0 and s1 indexes.

[0121] FIG. 10 illustrates an interlace-based RB resource allocation method applied to the present disclosure. PUCCH / PUSCH transmission can be performed using RB resources allocated on an interlace basis in an unlicensed band. Here, the reference point for the RB resources allocated on an interlace basis may be point A1010. The terminal may obtain information about point A1010 through base station signaling, as described above. Furthermore, CRBs may be resource blocks defined / configured with reference to point A1010, which is the starting point of the transmission bandwidth on a carrier. That is, when PUCCH / PUSCH transmission is performed on interlace-based RB resources, the interlaces can all be used on the carrier based on the same configuration with reference to reference point A1010 and CRBs. As an example, existing wireless communication systems (e.g., LTE LAA) and wireless communication systems (e.g., NR) can perform PUCCH / PUSCH transmission on interlace-based RB resources as described above, but are not limited thereto.

[0122] For example, in the case of a 15 kHz SCS, M=10 interlaces can be defined for all bandwidths. In the case of a 30 kHz SCS, M=5 interlaces can be defined for all bandwidths. Furthermore, X bits can be provided for interlace allocation in frequency resource allocation-related signaling. As a specific example, in the case of a 30 kHz SCS, if X is 5, the X bits can indicate all possible interlace combinations. As another example, in the case of a 15 kHz SCS, if X is 6, the X bits can indicate the starting interlace index and the number of consecutive interlaces. For example, 55 values may be required based on the combination of the starting interlace index and the number of consecutive interlaces. Therefore, when indicated by 6 bits, there can be 9 remaining RIV values, and the 9 remaining RIV values can indicate specific pre-defined interlace combinations.

[0123] Furthermore, Y bits can be provided for RB set allocation in frequency resource allocation-related signaling. The RB set allocation can be a start and end RB set based on the RIV format. Here, the RB sets can always be consecutive. Furthermore, as an example, when two adjacent RB sets are allocated, a guard band between the RB sets can be allocated and can be used as a frequency resource.

[0124] For example, in unlicensed bands, a method may be needed to allow various wireless access technologies / systems (e.g., Wi-Fi, LAA, NR-U, etc.) to use channels fairly and closely. For example, regulations (e.g., ETSI rules) for channel access may be provided, focusing on the above-mentioned 5 GHz and 6 GHz frequency bands, and items such as those shown in Table 10 below may be specified, but are not limited thereto.

[0125] [Table 10]

[0126] Here, the FBE (Frame Based Equipment) and LBE (Load Based Equipment) rules can be supported as channel access methods based on Table 10. As an example, the LBE channel access rule can take into account the factors in Table 11 below. Channel access can be performed by determining whether or not a channel is occupied based on CCA measurement. In addition, transmission based on an occupied channel can be performed after determining the transmission power based on the channel occupation.

[0127] [Table 11]

[0128] In addition, a channel access priority class (CANC) can be set for channel access, which may be similar to Table 12 below. Here, the priority class can define a priority based on a specific traffic type and quality of service (QoS) requirements. As an example, four priority classes can be defined in Table 12. Here, a different priority counter (p) value can be defined for each priority class. In this case, the higher the priority class, the lower the priority counter value.

[0129] Further, as an example, the channel occupancy time (CONT) may be a transmission burst interval. Here, the maximum COT limit may be determined differently for each priority class, and a higher priority class may have a shorter maximum COT interval. That is, the higher the priority class, the lower the priority counter value may be and the shorter the maximum COT interval may be.

[0130] Furthermore, as an example, the contention window (CW) may be a window used to select a counter value for performing a backoff procedure for channel access, where the contention window may be different for each priority class, which may be similar to Table 12 below.

[0131] [Table 12]

[0132] FIG. 11 is a diagram illustrating a method for performing a listen before talk (LBT) procedure in an unlicensed band to which the present disclosure can be applied. As an example, a Type 1 LBT procedure (LBT category 4) can be considered based on the LBE described above. The LBT procedure can be configured based on Category 1 to Category 4, which will be described later. Referring to FIG. 11, a transmitting node can wait for a defer period to determine whether a channel is available (S1110). Here, the defer period can be determined based on the priority class in Table 13 below. As an example, the defer period can measure whether a channel is available for at least 25 us. Here, it can be considered that feedback information regarding data transmission is transmitted within a maximum of 16 us. Taking the above into consideration, the defer period can measure whether a channel is available for at least 25 us.

[0133] Thereafter, if the node determines that the channel is available during the deferral period, it can perform a backoff procedure. At this time, the backoff counter N can be initialized to any value between 0 and the CW value (S1120). That is, any value between 0 and CW can be used as the backoff counter. Here, it is possible to count whether the channel is available based on 9us slots, and perform backoff by the backoff count value. Here, a larger average backoff value can be set based on a larger contention window, which can reduce the collision probability.

[0134] Thereafter, it is determined whether the backoff counter value is 0 (S1130). If the backoff counter value is 0, the node can perform transmission. The node can use the channel for transmission up to the maximum COT that can be occupied based on the priority class. On the other hand, if the backoff counter value is not 0, the backoff counter value can be decremented (S1140). Then, it is determined whether the next 9 us slot is idle (S1150). At this time, if the 9 us slot is idle, it checks again whether the backoff counter value is 0. If the backoff counter value is not 0, it repeats the operation of decrementing the backoff counter value. When the backoff counter value becomes 0, the above-mentioned transmission can be performed.

[0135] On the other hand, if the channel is not idle in the 9 us slot, the node waits again for the deferral interval and then checks whether the channel is available based on the backoff counter value (S1160). Based on the above, the node can occupy the unlicensed band and perform transmission. Furthermore, as an example, the deferral interval, possible contention window value, and maximum COT for the downlink / uplink based on the priority class may be the same as those in Table 13 below.

[0136] [Table 13]

[0137] Here, as an example, the size of the contention window may be adjusted based on HARQ feedback. Specifically, if the HARQ feedback received for the first transmission performed by the node within the COT is a NACK, the size of the contention window may be increased by up to twice to account for retransmission. On the other hand, if the HARQ feedback received for each transmission is an ACK, the size of the contention window may be reset to the CW min value. In this case, adjusting the size of the contention window for the first transmission within the COT may cause a collision in the first transmission after the node occupies the channel, and in such cases, it is necessary to update the size of the contention window. On the other hand, receiving a NACK for a transmission after the first transmission within the COT may be more likely to occur due to poor channel conditions or other reasons than a collision. Therefore, the size of the contention window may be adjusted based on the feedback of the first transmission within the COT, as described above.

[0138] As another example, the contention window adjustment for configured grant-based downlink / uplink (DL / UL) transmission may be performed based on feedback information on the downlink / uplink, respectively. Furthermore, as another example, when there is no downlink feedback transmission in uplink grant (UL grant-based uplink transmission), the contention window adjustment may be performed through a new data indicator (NDI), but is not limited to a specific embodiment.

[0139] Further, as an example, the energy detection (ED) threshold (TL) may be determined based on parameters, channel bandwidth, and other values. As another example, the ED threshold may be determined based on whether the carrier frequency is shared with other wireless access technologies (e.g., Wi-Fi) or whether the installation method ensures the use of only a specific wireless communication system (e.g., NR). As a specific example, the maximum threshold in the 5 GHz band coexisting with other systems may be set to −72 dBm for a 20 MHz carrier. Here, −72 dBm may be a value determined in comparison with other wireless communication systems (e.g., Wi-Fi systems), but is not limited to a specific embodiment. As another example, when the carrier frequency is used exclusively with a specific wireless communication system (e.g., NR), the maximum threshold may be −62 dBm for a 20 MHz carrier, and the threshold for uplink transmission may be set through RRC signaling based on regulations, but is not limited to a specific embodiment.

[0140] Next, FIG. 12 illustrates COT sharing and discovery burst transmissions applied to the present disclosure. Referring to FIG. 12, when a channel is occupied based on the aforementioned Type 1 LBT procedure, transmission can be performed within the COT. Here, Type 2 transmission can have three options based on the gap duration within the COT, as shown in Table 14 below. For example, Type 2A (LBT cat2) transmission sets the COT gap to 25 us or more and can be used for discovery burst transmission. For example, Type 2A can be considered for SSB transmission, but is not limited thereto. For another example, Type 2B transmission can apply a COT gap of 16 us. Furthermore, Type 2C transmission can apply a COT gap of 16 us or less. For example, if the next transmission is at most 16 us, idle sensing may not be required, and Type 2C can be applied.

[0141] [Table 14]

[0142] Here, due to the above-mentioned COT sharing, the gap may be smaller than the OFDM symbol duration. This is because the OFDM symbol-based resource allocation method may be insufficient, and a method of indicating CP extension can be applied taking the above-mentioned issue into consideration. That is, it is possible to indicate that the CP is extended earlier than the OFDM symbol boundary, and one of the following Table 15 can be indicated.

[0143] [Table 15]

[0144] As an example, Figure 13 is a diagram illustrating a method for applying a CP extension to an uplink when COT sharing is performed between a downlink and an uplink, which is applicable to the present disclosure. Figure 13 may illustrate, but is not limited to, a case in which a 16 us gap is present based on COT sharing and C2 is set to 1. Referring to Figure 13, a TA value can be considered to ensure a 16 us gap between the downlink and the uplink in a base station. As an example, the C value can be set through RRC signaling. Furthermore, a CP extension for uplink transmission can be indicated in an uplink grant.

[0145] As another example, a case where channel access is performed based on the FBE method can be considered. FBE may be a channel occupation method applicable to areas where the absence of other systems is guaranteed by regulation (e.g., a specific building or factory). Here, when channel access is performed based on the FBE method, transmission can start at a specific time. As a specific example, FIG. 14 illustrates a semi-static channel access procedure applicable to the present disclosure. Referring to FIG. 14, one COT can be started every Tx ms. At this time, the channel can be occupied if it is idle for at least 9 us before the COT. Here, Tx ms can be set to a value between 1 ms and 10 ms. Furthermore, the gap can be at least 5% of Tx. Here, COT sharing can be used similarly to LBE, and the gap can be at most 16 us.

[0146] As an example, Figure 15 illustrates a method for performing channel occupation applicable to the present disclosure. Referring to Figure 15, before performing transmission on an operating channel, a device may perform a CCA check based on energy detection with a CCA observation period of no less than 20 us. Furthermore, as an example, when transmitting a control frame (e.g., ACK, Block ACK) in consideration of multicast, the transmission may skip the CCA procedure and be performed immediately after packet reception. That is, the terminal may perform control frame transmission without a new CCA procedure, but may not exceed the maximum COT.

[0147] For example, if a device transmits an ACK / NACK signal after receiving data, the device can skip CCA, but this must be within the maximum COT. Also, for example, in short control signaling, a signal having a maximum duty cycle of 5% or less of 50 ms in the observation period can be transmitted without CCA, but this is not limited to a specific form.

[0148] Further, as an example, LBT categories can be considered, including category 1, which performs transmission immediately after a short switching gap, category 2, which performs LBT without random backoff, category 3, which performs a fixed-size contention window and random backoff, and category 4, which performs a variable-size contention window and random backoff.

[0149] Specifically, Category 1 may be a scheme in which transmission is performed immediately after a short switching gap. In this case, Category 1 can be used to perform transmission immediately after a switching gap within one COT. The switching gap from receive to transmit within one COT may include the transceiver switching time and may not be longer than 16 μs. Furthermore, as an example, Category 2 may be an operation in which LBT is performed without random backoff. For example, when performing LBT, initial CCA may be performed, and if the channel is idle, the channel is occupied and data is transmitted over an unlicensed channel. Here, random backoff counting may not be performed. On the other hand, Category 3 may be an LBT scheme in which a contention window of a fixed size is used and random backoff is performed. When LBT is performed based on Category 3, if initial CCA is performed and the channel is idle, random backoff may be performed within a fixed contention window (e.g., a fixed “q” value, where q is a value that determines the contention window size by selecting a random N counter between 0 and q). As an example, the random backoff operation may involve randomly selecting a counter value within the contention window, decrementing the count depending on whether the channel is idle for each ECCA slot, and occupying the channel when the value is 0.

[0150] As another example, Category 4 may be an LBT scheme with a variable-sized contention window and random backoff. Category 4 may differ from Category 3 in that it has a variable contention window. However, the operation of applying the N value based on the random backoff value to occupy a channel may be similar. That is, Category 4 may be the same as Category 3 except that the contention window size may vary based on time or events, and may be used in multiple wireless communication systems (e.g., LAA, NR-U, WiFi). This is not limited to a specific embodiment. Here, as an example, different channel access categories (e.g., LBT categories) may be defined and used for transmission of different channels / signals within one COT. Furthermore, as an example, in a new wireless communication system (e.g., NR-U), Category 4 LBT and Category 2 may be used within a COT, which may be similar to Table 16 below. Category 2 LBT may be used for discovery burst transmission when there is no unicast transmission and its transmission characteristics are constrained transmission, with a transmission time of 1 ms or less and a duty cycle of 5% or less, but is not limited to a specific form.

[0151] [Table 16]

[0152] The following describes a method for allocating frequency resources so that sidelink communication in a wireless communication system (e.g., NR) can operate on an unlicensed frequency band. For example, the size of an RB set included in 20 MHz in an unlicensed band (e.g., NR-U) of a current wireless communication system may vary depending on the SCS. For example, in the case of a 15 kHz SCS, the size of the RB set may be 100 to 110 PRBs. Furthermore, in the case of a 30 kHz SCS, the size of the RB set may be 50 to 55 PRBs. In this case, for example, when allocating RB resources based on interlaces, some interlaces may include 11 PRBs, while the remaining interlaces may include only 10 PRBs.

[0153] Here, as an example, a case where subchannel sizes are different to use the entire bandwidth in the sidelink may be considered. That is, a case where the number of PRBs included in each subchannel is set to be different may be considered. However, if different subchannel sizes are set, it may be difficult to ensure transmission when retransmissions are performed after the initial transmission of TBs having the same transport block size (TBS). In consideration of the above, the subchannel size (i.e., the number of PRBs) may be set to the same for each subchannel, but is not limited thereto. However, if the subchannel size is set to the same for each subchannel, some of the subchannels may not be used in one interlace based on interlace-based RB resource configuration.

[0154] 16 is a diagram illustrating a method for configuring RBSs in a BWP and a resource pool in a sidelink unlicensed band to which the present disclosure is applicable. The frequency domain resource structure of a sidelink unlicensed band wireless communication system (e.g., NR SL-U) may consider a BWP (bandwidth part), a RP (resource pool), interlaced RBs, and an RBS (RB set). For example, an RBS may also be considered in an unlicensed band wireless communication system (e.g., NR U), and is not limited to a specific embodiment.

[0155] Referring to Figure 16, one sidelink unlicensed band (SL-U) BWP 1610 may be configured in a sidelink terminal, one SL-U RP 1620 may be configured in the SL-UBWP 1610, and two RBSs 1631 and 1632 may be configured in the SL-U RP 1620. However, this is merely an example for convenience of explanation and is not limited to the above-mentioned embodiment. Here, as an example, an interlaced structure may be considered in an SL-U system to satisfy the OCB and PSD requirements required in the unlicensed band. That is, in an SL-U system, CRB indexing may be performed based on point A, which is a reference frequency point of one carrier, and a sidelink interlaced structure may be applied. In Figure 16, a frequency domain corresponding to CBR index 47 to CRB index 90 can be configured in the SL-U BWP 1610 based on the SL-U BWP 1610 configuration, and frequency resources including two RBSs 1631 and 1632 can be configured based on the SL-U RP 1620 configuration, but this is only an example and is not limited thereto. Hereinafter, a method for configuring frequency domain resources for an SL-U system as shown in Figure 16 and a method for allocating resources for actual SL-U data transmission based thereon will be described.

[0156] For example, the channel access procedure of a sidelink unlicensed band wireless communication system (e.g., NR SL-U) can apply the above-described Type 1 channel access procedure and Type 2 channel access procedure. Also, for example, UE-to-UE COT sharing can be applied between terminals operating in a sidelink unlicensed band. That is, a transmitting terminal can share a portion of unlicensed resources acquired through the LBT procedure with a receiving terminal or another terminal.

[0157] For example, in a sidelink unlicensed band wireless communication system (e.g., NR SL-U), frequency resources can be configured based on subchannels, as in an existing sidelink wireless communication system (NR SL). That is, the term "subchannel" can be used in NR SL-U as in NR SL. However, the names of subchannels can be configured differently in a sidelink unlicensed band wireless communication system (e.g., NR SL-U) and are not limited to a specific embodiment. For convenience of explanation, the following description will be based on subchannels.

[0158] As an example, an interlace-based RB structure for satisfying the requirements of the unlicensed spectrum described above may be defined with M RBs in the frequency domain. Here, the interlace-based RB structure may be defined as RBs spaced apart by a uniform number of RBs. As another example, the interlace-based RB structure may also be set to RBs spaced apart by a non-uniform number of RBs, and is not limited to a specific embodiment.

[0159] Here, the interlace-based RB structure may be pre-configured commonly for NR SL UEs, cell-specific or carrier-specific, based on bandwidth / pneumatics. As another example, the interlace-based RB structure may be configured specific to a physical link between UEs through higher layer configuration, and is not limited to a specific embodiment. In this case, the interlace-based RB structure may be applied to all interlaces regardless of carrier bandwidth. Therefore, the interlace-based RB structure may be configured by a CRB defined based on point A, a specific reference point in the frequency domain. Here, one sub-channel may be pre-defined to have k interlaces. As another example, one sub-channel may be configured with k interlaces through higher layer signaling. k may be the number of interlaces per sub-channel. The number of interlaces per sub-channel may have a fractional (or decimal) or integer value, as will be described later. Furthermore, as an example, when multiple RBSs are configured in one SL BWP, the frequency resource allocation instruction may include RBS allocation information and sub-channel or interlace-based RB frequency resource allocation information.

[0160] As another example, in a sidelink unlicensed spectrum system (e.g., NR SL-U), resource allocation can be performed based on interlace-based RB units rather than "subchannel" units. In this case, the frequency resource allocation unit can be an interlace-based RB unit rather than the existing subchannel, but this is merely an example and is not limited to a specific embodiment.

[0161] Hereinafter, both subchannel units and interlace-based RB units can be considered as resource allocation units in the frequency domain. Herein, a subchannel can be configured with k interlaces or a number of consecutive RBs. However, for convenience of explanation, a "subchannel unit" based on an interlace structure will be described as a unit of frequency resource allocation. However, frequency resource allocation can also be configured in interlace-based RB units rather than in subchannel units by applying the proposed method, and is not limited to a specific form.

[0162] Figure 17 is a diagram illustrating time and frequency resources of a PSCCH to which the present disclosure can be applied. One sidelink slot (SL slot) can include one automatic gain control (AGC) symbol. Here, the PSCCH may be transmitted over two or three OFDM symbols starting from the symbol next to the AGC symbol at the start of the slot in the time domain. Furthermore, the PSCCH can be set to one of {10, 12, 15, 20, 25} PRBs in the frequency domain, as shown in Table 17 below.

[0163] Here, the frequency resources configured for the PSCCH may be allocated within one subchannel. Furthermore, the PSCCH DMRS may be located in all PSCCH symbols and may be located in every fourth RE (Resource Element) among 12 REs in one PRB in terms of frequency, as shown in FIG. 17. For example, in order to reduce the impact of PSCCH transmission collision between UEs with different OCC codes in the frequency domain, the PSCCH DMRS may be applied, and the PSCCH may be allocated in the time / frequency domain as shown in FIG. 17. When sidelink communication is performed based on a sidelink unlicensed band, a method for allocating and transmitting PSCCH resources may be required, which will be described below.

[0164] [Table 17]

[0165] As an example, at least one RBS may be configured in a resource pool within one SL BWP. Here, the available PSCCH transmission resource area for PSCCH transmission of a transmitting terminal may be dynamically changed depending on whether a channel access requested for each RBS (LBT BW) on the unlicensed spectrum is successful (whether the LBT is successful or not). Further, as an example, to meet the requirements for the unlicensed spectrum, such as OCB and PSD, a subchannel having an "interlace-based RB structure" or an interlace-based RB structure may be configured in the resource pool, as described above. As an example, PSCCH resources may need to be allocated in a manner different from that of FIG. 3, taking into account various conditions required for using the unlicensed spectrum, as will be described below.

[0166] The subchannel-based time resource and frequency resource configuration for SL communication may be as shown in Table 18. However, a method for the SL resource pool to meet the unlicensed band regulations may be required, and the following description will be based on the case where interface-based transmission is performed, but is not limited to this.

[0167] [Table 18]

[0168] First SCI and second SCI resource allocation method

[0169] The relationship between the CRB, interlace index, and subchannel indexing can be configured in various ways. For example, PSCCH resource allocation may be performed based on physical resources associated with a specific subchannel index within the PSSCH resources designated for SL communication. For another example, PSCCH resource allocation may be performed based on physical resources associated with a specific interlace index within the PSSCH resources designated for SL communication. That is, PSCCH resource allocation may be performed based on a specific index of a subchannel or interlace considered as a basic sidelink resource allocation structure. Alternatively, PSCCH resource allocation may be performed based on a PSCCH PRB configured within the specific subchannel or interlace within the PSSCH resources designated for SL communication. Hereinafter, it is assumed that PSCCH resources can be allocated based on a basic resource allocation structure (e.g., subchannel or interlace) regardless of which physical resource structure and resource index are applied in the SL unlicensed band. The PSCCH resource allocation method proposed below can be applied to the first SCI transmitted over the PSCCH described above. However, the PSCCH resource allocation method is not limited to the first SCI and can also be considered as an allocation method for second SCI resources on the PSSCH, which will be described later.

[0170] As a specific example, the second SCI may be allocated together with the PSSCH / PSCCH transmission on other OFDM symbols / frequency resources that do not overlap with a specific interlace / specific RB in a specific subchannel that is a frequency resource index determined for PSCCH transmission in the PSSCH resource region allocated for SL communication (i.e., within the same subchannel index / interlace index / RB). Also, as an example, hereinafter, the PSCCH may be allocated in the order of a specific SL carrier index (in the case of SL CA), a specific RBS, a specific subchannel index, and a specific interlace RB index, as will be described later. Furthermore, the second SCI may be allocated to a part of an existing PSSCH region using at least one resource among resources within the same carrier, RBS, subchannel, and interlace index as the resource region to which the PSCCH is allocated, as will be described later.

[0171] For the sake of convenience, the following describes a resource allocation method for PSCCH allocation, but the following resource allocation method can also be considered as a resource allocation method for transmitting a second SCI transmitted within a PSSCH within a selected resource region, and is not limited to a specific embodiment.

[0172] Resource Allocation Method for PSCCH Blind Monitoring

[0173] A terminal operating in an SL unlicensed band can be configured to perform SL control signal and data transmission / reception based on an interlaced RB structure based on a configuration of a higher layer. As another example, a terminal operating in an SL unlicensed band can be pre-configured to perform SL control signal and data transmission / reception on interlaced RBs based on the provisions of the unlicensed band. That is, the terminal can perform SL control signal and data transmission / reception on interlaced RBs based on a configuration of a higher layer or a predetermined configuration. The configuration information may be provided from the base station through higher layer signaling, or, if such information is not available, may be pre-configured in the terminal independently for each carrier / BWP or resource pool.

[0174] Furthermore, one or more RBSs corresponding to the LBT bandwidth on the unlicensed bandwidth may be configured to exist in one resource pool. Here, the RBS and resource pool configuration may be provided by the base station to the SL terminal through higher layer (e.g., RRC, MAC) signaling. As another example, pre-defined parameters (i.e., pre-defined parameters) may be provided in advance based on values stored in the terminal and then applied. As an example, if pre-defined parameters (i.e., pre-defined parameters) are provided in advance based on values stored in the terminal and then applied, when the terminal connects to a network (e.g., NR, LTE), they may be replaced with new parameter values and applied through higher layer signaling from the base station, and this is not limited to a specific embodiment.

[0175] Here, for example, PSCCH resources may be allocated within each RBS, regardless of PSSCH resource allocation associated with the success or failure of LBT performed on multiple RBSs. More specifically, a receiving terminal can confirm PSSCH resource allocation information based on SCI(PSCCH) detection and receive PSSCH through this. Here, the receiving terminal may receive PSSCH through multiple consecutive RBSs without any problems. On the other hand, when the receiving terminal attempts to decode PSCCH, it cannot confirm in advance the RBS and subchannel / interlace on which the PSCCH is received, and can confirm the PSCCH through blind decoding. Therefore, the terminal must perform blind decoding in all SL resource pools. In the case of an SL resource pool in an unlicensed band, the range of PSSCH transmission frequency resources may be dynamically changed depending on which RBS among multiple RBSs in the SL resource pool the LBT is successful on. Furthermore, for example, a guard band may exist between two adjacent RBSs, as described above. When a resource pool includes two adjacent RBSs, the PRBs within the guard band can also be used for SL communication as resources in the resource pool. That is, the resource pool can use not only the PRBs in the two adjacent RBSs but also the PRBs in the guard band between them as resources for SL communication. Therefore, from the perspective of the transmitting terminal, it can determine whether to use frequency resources in the guard band for at least PSSCH transmission and reception based on whether LBTs between two adjacent RBSs are successful. For example, if LBTs for two adjacent RBSs are all successful, the guard band resources between the frequency resources in the guard band between the adjacent RBSs can also be used for PSSCH transmission based on at least one of subchannels and interlace RBs.

[0176] As a specific example, Table 19 below shows a case where a resource pool configured in a receiving terminal includes four RBSs. The success or failure of the LBT may differ for each RBS configured in the resource pool. Since the receiving terminal cannot check whether the LBT is successful on which RBS before receiving the PSCCH, it needs to check the PSCCH through blind decoding. Here, the blind decoding combination for receiving the PSCCH may be as shown in Table 19 below, taking into account various resource utilization situations. That is, a problem may occur where the receiving terminal must perform an increased number of blind decodings considering the success or failure of the LBT on each RBS, and a solution to this problem may be required.

[0177] [Table 19]

[0178] The range of physical resources within a resource pool including at least any subchannel or interlace may vary depending on whether the LBT is successful. Therefore, as shown in Table 19, the number of blind decoding combinations for checking the PSCCH may increase, which may increase the complexity of blind decoding and the power consumption of the terminal. In consideration of the above, PSCCH resource allocation may be limited to each RBS. That is, PSCCH resource allocation may be limited to each RBS resource regardless of whether the LBT is successful for two adjacent RBSs.

[0179] Here, as an example, if one or more RBSs are configured in a resource pool and LBT is successful on only one of the RBSs, the terminal can perform PSCCH and PSSCH transmission in the RBS where LBT is successful. That is, if LBT is successful on only one of the RBSs in a resource pool configured based on the SL unlicensed band, the terminal can perform PSCCH and PSSCH transmission in the RBS.

[0180] On the other hand, a case where the LBT of at least one adjacent (consecutive) RBSs among multiple RBSs in the SL resource pool is successful can be considered. Here, the PSCCH can be transmitted in a specific RBS among at least one adjacent RBS that has successfully undergone the LBT. That is, the PSCCH may be transmitted through a specific RBS among multiple RBSs (hereinafter referred to as option 1). Here, as an example, the PSCCH may be transmitted through an RBS with the lowest or highest RBS index among the RBSs that have successfully undergone the LBT. As another example, the PSCCH may be transmitted through a specific RBS selected by the transmitting terminal among the RBSs that have successfully undergone the LBT, and this is not limited to a specific embodiment. Figure 18 illustrates a method of allocating PSCCH resources to adjacent RBSs according to one embodiment. As another example, both the transmitting terminal and the receiving terminal may be configured in advance by a higher layer to always perform PSCCH transmission through a specific RBS among the RBSs configured in the resource pool. In this case, the transmitting terminal must have a successful LBT in at least a specific RBS in order to transmit the PSCCH, but the receiving terminal may have the advantage of not having to monitor the PSCCH in all RBSs. Referring to FIG. 18, a terminal may transmit PSSCH 1811 and PSCCH 1812 to other terminals through resources in a resource pool established based on the SL unlicensed band. RBS #0 (1821) and RBS #1 (1822) may be adjacent RBSs, and a guard band 1823 may exist between RBS #0 (1821) and RBS #1 (1822). As an example, consider the case in FIG. 18 where both the LBT in RBS #0 (1821) and the LBT in RBS #1 (1822) are successful. In this case, the terminal may transmit PSCCH 1812 in RBS #0 (1821) determined by the above method, but may not transmit PSCCH 1812 in RBS #1 (1822). The terminal can transmit PSSCH 1811 and PSCCH 1812 in RBS #0 (1821) and transmit only PSSCH 1811 in RBS #1 (1822).Furthermore, the guard bands 1823 between adjacent RBSs may also be resources in the resource pool, so that the PSSCH 1811 transmission can be carried out through these resources.

[0181] That is, if the LBT is successful on adjacent (contiguous) RBSs in the resource pool of the SL unlicensed band, the terminal can perform PSCCH transmission only in a specific one of the RBSs where the LBT was successful. As an example, the specific one RBS may be the RBS with the lowest RBS index. As another example, the specific one RBS may be the RBS with the highest RBS index or an RBS set based on specific conditions, and this is not limited to a specific embodiment. That is, the PSCCH may be transmitted only through a specific one (part) of the adjacent RBSs where the LBT was successful.

[0182] As another example, if the LBT of at least one adjacent (consecutive) RBSs in a plurality of RBSs in an SL resource pool is successful, the PSCCH may be transmitted in each of the at least one adjacent RBS where the LBT was successful. That is, the PSCCH may be transmitted in each of the plurality of RBSs (hereinafter referred to as option 2). That is, if the LBT is successful on adjacent (consecutive) RBSs in the resource pool of the SL unlicensed band, the UE may transmit the PSCCH in the frequency resources of each RBS where the LBT was successful. Here, PSCCH processing may perform channel coding and rate matching based on the amount of PSCCH transmission resources allocated to one RBS. For example, the amount of PSCCH transmission resources may be, but is not limited to, the number of OFDM symbols and the number of interlaced RBs set by upper layer parameters. That is, PSCCH processing may be performed based on the PSCCH transmission resources allocated in one RBS. The PSCCH transmitted in other RBSs may be duplicated by duplicating the PSCCH. That is, the PSCCH transmitted in each RBS may be copied and transmitted on the same PSCCH. Furthermore, for example, the frequency resource-related index and position of the PSCCH within an RBS may all be the same. As another example, the frequency resource-related index and position of the PSCCH may be determined based on a preset offset value for each RBS. For example, the frequency resource-related index and position of the PSCCH may be determined based on the RBS with the lowest index among the RBSs that have succeeded in the LBT, and the offset may be determined according to the RBS index. That is, the frequency resource-related index and position of the PSCCH may be determined in the RBS with the lowest index, and in other RBSs, the PSCCH may be allocated to frequency resources shifted by the offset determined according to the RBS index, but this is not limited to this. As another example, PSCCH channel coding and rate matching may be performed taking into account the total amount of PSCCH resources transmitted in successful RBSs based on the same SCI information.This method has the advantage that more redundant channel coded bits can be transmitted to the receiving terminal than the previously described method, and therefore the reception performance can be further improved. In addition, the PSSCH may be transmitted through resources within the guard band between the RBS that has succeeded in the LBT and the adjacent RBS, as described above.

[0183] Figure 19 illustrates a method for allocating PSCCH resources in adjacent RBSs according to an embodiment. Referring to Figure 19, a terminal can transmit PSCCH 1911 and PSCCH 1912 to other terminals through resources in a resource pool established based on the SL unlicensed band. In this case, RBS #0 (1921) and RBS #1 (1922) may be adjacent RBSs, and a guard band 1923 may exist between RBS #0 (1921) and RBS #1 (1922). As an example, consider a case in Figure 19 where both the LBT of RBS #0 (1921) and the LBT of RBS #1 (1922) are successful. In this case, the terminal can transmit PSCCHs 1912 and 1913 in RBS #0 (1921) and RBS #1 (1922). Here, the PSCCH 1913 transmitted in RBS #1 (1922) may be a PSCCH that is a duplication of the PSCCH 1912 transmitted in RBS #0 (1921). The terminal can transmit the PSCCH 1911 in RBS #0 (1921), RBS #1 (1922), and guard band 1923.

[0184] As another example, the method of copying the PSCCH and transmitting it in each RBS may vary depending on the configuration of a higher layer. For example, information instructing PSCCH copy transmission may be configured by the configuration of a higher layer, and if the information instructs PSCCH copy transmission, the PSCCH may be copied and transmitted in each RBS. Specifically, if a configuration instructing PSCCH copy transmission exists, the UE may copy and transmit the PSCCH in each RBS where LBT is successful (Option 2). On the other hand, if a configuration instructing PSCCH copy transmission does not exist, even if LBT is successful in multiple RBSs, the UE may transmit the PSCCH through a specific RBS index (e.g., the lowest RBS index among the RBSs where channel occupancy is successful) (Fallback) (Option 1).

[0185] As another example, an operation in which the PSCCH is transmitted through one RBS when the LBT is successful on adjacent RBSs (option 1) or an operation in which the PSCCH is transmitted through each RBS after PSCCH copying (option 2) can be indicated through at least one of the SCI and MAC CE. Furthermore, as another example, the above-mentioned operations may be preset. As another example, in the absence of specific configuration or signaling, a specific operation among the above-mentioned operations may be set as a basic operation (e.g., option 1), but this is not limited to a specific embodiment.

[0186] For example, four RBSs may be configured in one resource pool. However, this is merely an example for convenience of explanation and is not limited to the above-described embodiment. For example, interlace indexes and subchannel indexes may be assigned in a 1:1 relationship, but the present invention is not limited to this. Here, the terminal may independently perform an LBT procedure for each frequency band corresponding to each RBS in the unlicensed band. In this case, the PSCCH / PSSCH resource region may differ depending on the LBT execution result. For example, resource allocation may be performed based on consecutive subchannels in the SL unlicensed band. As another example, interlace-based resource allocation may be configured or defined in addition to the consecutive subchannel-based resource allocation method in the SL unlicensed band. This may be applied to meet the above-described PSD / OCB requirements for the unlicensed band, but is not limited to a specific embodiment.

[0187] Therefore, when at least one subchannel is scheduled within one RBS, PSSCH resources (e.g., subchannel units) may be allocated at regular frequency intervals (e.g., every M interlaces) across the entire band within the RBS. The following description will be based on the case where SL transmission and reception are performed on consecutive adjacent RBSs. Here, as mentioned above, resources on guard bands between RBSs can be utilized when consecutive RBSs occupy the channel. Therefore, since the terminal can perform SL transmission on as many consecutive frequency resources as possible, it is possible to increase frequency utilization efficiency and transmission power efficiency. Considering the above, the following description will be based on the case where SL transmission is performed on consecutive adjacent RBSs, but is not limited thereto.

[0188] Figure 20 illustrates an embodiment in which multiple RBSs are configured in one resource pool. Referring to Figure 20, a terminal can successfully perform LBT in RBS #0 (2010). The terminal can use subchannels #0 and #1 associated with RBS #0 (2010) for PSCCH / PSSCH transmission. PSCCH resource allocation may be limited to each RBS to minimize blind decoding and power consumption. That is, the transmitting terminal can determine, using the proposed method, that the PSCCH is allocated only to RBS #0 (2010). The receiving terminal can perform blind detection for PSCCH reception on each subchannel allocated to each RBS, excluding the guard bands, of the four RBSs 2010, 2020, 2030, and 2040 configured in the resource pool. As another example, the receiving terminal may perform blind detection for PSCCH reception for each interlace resource associated with each subchannel allocated within each of the four RBSs 2010, 2020, 2030, and 2040 configured in the resource pool, excluding the guard bands. That is, the receiving terminal may perform PSCCH reception without increasing the complexity for blind detection, regardless of the LBT result performed by the transmitting terminal. As another example, when configured to transmit the PSCCH only on specific RBSs according to the proposed method as described above, the receiving terminal may perform blind decoding for PSCCH reception only on specific RBSs among the configured RBSs.

[0189] 21 and 22 are diagrams illustrating a case where multiple RBSs are configured in a resource pool according to an embodiment. Referring to FIG. 21, unlike FIG. 20, LBT was successful on two adjacent RBSs (e.g., RBS#0 and RBS#1, 2110, 2120). However, since the receiving terminal cannot recognize information regarding the success or failure of the transmitting terminal's LBT, it can perform blind detection assuming PSCCH transmission limited within the LBT BW(RBS). Here, as an example, the transmitting terminal has successfully performed LBT on two consecutive RBSs 2110 and 2120, but can only perform PSCCH transmission within one specific RBS. Here, the PSCCH transmission resource may be the lowest interlace RB associated with the lowest subchannel index within the RBS. However, this is merely an example, and the PSCCH transmission resource may be assigned to an interlace RB index that is different from certain other subchannel indexes.

[0190] 22(a), the transmitting terminal may successfully perform LBT in two consecutive RBSs 2210 and 2220 and perform PSCCH transmission in each RBS. Here, the PSCCH transmission resource may be the lowest interlace RB associated with the lowest subchannel index in each RBS. However, this is merely an example, and the PSCCH transmission resource may be assigned to an interlace RB index that is different from certain other subchannel indexes.

[0191] As another example, referring to FIG. 22(b), when one or more RBSs are configured in the frequency domain and PSSCH transmission is performed over one or more adjacent RBSs, a method can be applied in which interlace RBs associated with the same specific subchannel index (e.g., the lowest subchannel index among the PSSCH-scheduled subchannels) among the scheduled subchannels for the PSSCH between the adjacent RBSs are sequentially allocated for PSCCH transmission. That is, unlike the above-described Option 1 and Option 2 related to PSCCH blind decoding, one PSCCH can be transmitted over adjacent RBSs. Here, since it is not possible to know in advance from the perspective of the receiving terminal on which RBS the LBT will be successful and the transmitting terminal will perform SL data transmission, a problem may occur in which the complexity of blind decoding for PSCCH decoding increases. However, since the constraint on PSSCH scheduling that requires resources at least larger than the PSCCH transmission resources may be removed, the above-described method can be applied taking trade-offs into consideration.

[0192] As a specific example, if LBT is successful on RBS#0 (2210) and RBS#1 (2220) for PSSCH scheduling, PSSCH transmission can be performed using specific subchannels among the subchannels and associated interlace RBs within RBS#0 (2210) and RBS#1 (2220) and between RBS#0 (2210) and RBS#1 (2220) (whether or not resources can be utilized within the guard band between adjacent RBS#0 and #1 can be predetermined or configured). Here, the PSCCH can be transmitted by allocating the number of PSCCH RBs using the interlace RB associated with the smallest subchannel index among the subchannels allocated for PSSCH transmission within each RBS. That is, PSCCH RBs can be allocated between RBS#0 (2210) and RBS#1 (2220). As an example, the PSCCH RB resource allocation order can be allocated for the PSCCH for each interlace RB sequentially from the lowest frequency, but is not limited to this embodiment.

[0193] 23 and 24 are diagrams illustrating a case where multiple RBSs are configured in a resource pool according to an embodiment. Referring to FIG. 23, a terminal can successfully perform LBT using three RBSs (RBS#1, RBS#2, RBS#3, 2320, 2330, and 2340). In this case, PSCCH / PSSCH transmission can be performed using the lowest RBS among the RBSs 2320, 2330, and 2340 where LBT was successful. Furthermore, PSCCH transmission resources may be allocated starting with the lowest subchannel index within the RBS and the lowest interlace RB index associated with the lowest subchannel index.

[0194] On the other hand, referring to Figure 24, the terminal can successfully perform LBT in three RBSs (RBS#1, RBS#2, RBS#3, 2420, 2430, and 2440). In this case, PSCCH / PSSCH transmission may be performed in each of the successful LBT RBSs 2420, 2430, and 2440. PSCCH transmission resources may be allocated starting from the lowest subchannel index within each RBS and the lowest interlace RB index associated with the lowest subchannel index.

[0195] That is, if the LBT is successful on consecutive RBSs (i.e., the LBT is successful on one or more consecutive RBSs), the PSSCH transmission resource can be transmitted using additional frequency resources in the guard band between the resource in the RBS where the LBT was successful and the adjacent RBS where the LBT was successful. On the other hand, unlike the PSSCH resource allocation method, the PSCCH transmission resource can be allocated only within each RBS frequency resource within the actually scheduled PSCCH resource region, thereby preventing an increase in blind decoding and an increase in power consumption.

[0196] PSCCH resource allocation considering subchannel / interlace RB

[0197] For example, a subchannel may be configured using non-contiguous interlace-based RBs, and a PSCCH resource allocation method may be required for the non-contiguous interlace-based subchannels. Here, the resource allocation method may be performed within a slot including a subchannel-interlace RB unit for PSCCH resource allocation, but is not limited thereto.

[0198] As an example, the radio resource for PSCCH transmission may be determined as a specific RBS among the RBSs that have successfully passed the LBT based on whether the LBT of the RBSs in the resource pool has been successful, or may be determined within each RBS, as described above.

[0199] The following describes which resources among the scheduled resources are used to transmit the PSSCH. As an example, Table 20 and Table 21 may be tables showing the number of subchannels per RBS, the number of interlaces per subchannel, the number of interlaces (M), and the number of RBs per interlace (N) based on the subcarrier spacing. The resources for PSCCH transmission will be described taking Table 20 and Table 21 into consideration.

[0200] [Table 20]

[0201] [Table 21]

[0202] Subchannel and interlace RB frequency resource allocation for PSSCH transmission may be provided to the receiving terminal via SCI signaling. On the other hand, PSCCH frequency resources may be allocated based on higher layer parameters and may be as shown in Table 17 above. As an example, the parameter values in Table 17 may be values provided by higher layer parameters. The number of PSCCH transmission RBs associated with the frequency domain may be pre-provided and configured in the terminal as one of {10, 12, 15, 20, 25} PRB values. As another example, the number of PSCCH transmission RBs may be set to other values and is not limited to a specific embodiment.

[0203] In this case, for example, the PSCCH may be limited to be allocated to the lowest subchannel among the subchannels scheduled in consideration of the number of PSCCH RBs. However, as described above, instead of allocating the PSCCH only to the lowest subchannel among the subchannels scheduled in consideration of unlicensed band operation, a method of allocating the PSCCH to one or more subchannels may be considered. In this case, for example, a method of allocating the PSCCH to one or more subchannels may be considered based on the above-described requirements for the unlicensed band and an interlace-based structure.

[0204] Specifically, the interlaced RB structure to be applied to a 20 MHz unlicensed band / channel (LBT BW=RBS) can be determined depending on the SCS value and whether PSD / OCB is enabled. For example, the applied interlaced RB structure can be determined semi-statically. However, applying the interlaced RB structure semi-statically may reduce flexibility in configuration. The number of subchannels or the number of interlaced RBs per subchannel may be limited by the interlaced RB structure, which may affect the granularity and flexibility of scheduling allocation. On the other hand, the number of RBs for PSCCH transmission can basically determine the amount of resources taking into account PSCCH reception performance. Therefore, the main factor in determining the number of RBs may be the PSCCH coding rate, and the number of RBs can be appropriately set for reliable PSCCH reception. In consideration of the above, the PSCCH resource allocation method may differ from existing methods depending on the structure and configuration of the unlicensed carrier, which will be described below.

[0205] As an example, PSCCH resource allocation may be performed based on the number of PSCCH RB resources and the number of interlaced RBs per subchannel. Specifically, a case where the number of interlaced RBs per subchannel is equal to or greater than the number of PSCCH RBs (hereinafter referred to as case 1) and a case where the number of interlaced RBs per subchannel is smaller than the number of PSCCH RBs (hereinafter referred to as case 2) may be considered. Here, as an example, a case where PSCCH monitoring is configured or predetermined by a higher layer to be performed for every one or more subchannels may be considered.

[0206] In addition, more than one subchannel number unit can be set for each resource pool as the basic frequency unit for blind decoding through upper layer parameters. As a specific example, a terminal performing SL communication can allocate a PSCCH frequency resource within at least one of the two lowest subchannel indexes and interlace indexes on the frequency resources scheduled for SL data transmission. In this case, unlike the conventional operation in which blind decoding is performed for each subchannel, the receiving terminal can perform blind decoding for PSCCH reception for each two subchannels. Of course, in this case, there may be a restriction that resources for PSSCH transmission must use at least two subchannels, but there is also an advantage that PSCCH resource allocation can be more flexible.

[0207] Here, in Case 1, the number of interlace RBs per subchannel may be equal to or greater than the number of PSCCH RBs. Therefore, the PSCCH may be allocated within one subchannel. That is, RB resources for PSCCH transmission may be allocated to the interlace RBs included in the lowest subchannel among the scheduled subchannels. Here, the lowest subchannel is merely an example and is not limiting, and other specific subchannel indexes may also be used as a reference.

[0208] On the other hand, Case 2 may be a case where the number of interlace RBs per subchannel is smaller than the number of RBs set or determined for PSCCH transmission. That is, it may be a case where more PSCCH RBs are required than the number of interlace RBs present in one subchannel. Here, Case 2 may be applied when PSCCH monitoring is configured or pre-configured by an upper layer for one or more subchannels. As a specific example, a case may be considered where the number of interlace RBs per subchannel is smaller than the number of PSCCH RBs required for reliable PSCCH reception. Referring to Tables 19 and 20 above, the number of interlace RBs per subchannel may be 10 or 11. On the other hand, the number of PSCCH RBs may be set to any one of 12, 15, 20, and 25 PRBs among the upper layer parameters in Table 17. That is, it may be a case where the number of PSCCH RBs is greater than the number of interlace RBs per subchannel. Since more RBs than the number of PSCCH RBs may be required to successfully receive the PSCCH, there may be a limit to performing transmission based on one subchannel.

[0209] For example, the blind monitoring unit for PSCCH reception may be configured for at least each resource pool through higher layer parameters to have one or more subchannels. That is, it is possible to consider cases where the blind monitoring unit for PSCCH reception is not one subchannel. Here, for example, the PSCCH may be sequentially allocated and transmitted from the smallest subchannel index in the scheduled SL PSSCH resource region to the subchannel index corresponding to the number of subchannels for PSCCH monitoring that have been configured. For example, the PSCCH transmission may be allocated and transmitted to the two smallest subchannel indexes in the PSSCH resource region scheduled for SL data transmission. The receiving terminal may determine the blind monitoring unit for PSCCH reception (i.e., how many subchannel indexes are used as one PSCCH allocation) through higher layer parameters or a predetermined value, and may perform blind decoding for each configured resource unit. Here, the resource unit may be the number of subchannels or interlaced RBs, and may be provided as one or more possible values.

[0210] Below, a method for allocating PSCCH RBs will be described taking into consideration the above-mentioned cases 1 and 2. As an example, a new frequency resource allocation method needs to be defined from the viewpoint of defining a radio interface for SL transmission / reception on an unlicensed band, and this will be described.

[0211] As an example, PSCCH resource allocation may be performed within an RBS selected for scheduled PSSCH transmission. The PSCCH may be configured starting from the lowest interlace RB index(ies) included in the lowest subchannel index(ies) within the RBS, and allocated to resources corresponding to consecutive interlaces (or RBs). As another example, PSCCH allocation may be performed starting from the highest subchannel index(ies) or any subchannel index within the RBS, rather than the lowest subchannel index(ies) / interlace RB index(ies), and is not limited to a specific embodiment. Here, when PSSCH / PSCCH are allocated to one or more subchannels, the PSCCH may be allocated from the lowest subchannel up to the subchannel corresponding to the configured number of monitors.

[0212] FIG. 25 illustrates a method for allocating PSCCH RBs based on the interlaces associated within a subchannel, according to one embodiment.

[0213] Referring to FIG. 25, subchannel index #0 may be scheduled for PSSCH transmission within one RBS. Here, the number of interlaces per subchannel may be one. Subchannel index #0 may be configured to be associated with the interlace RB corresponding to interlace index #0. Alternatively, the number of interlaces M may be 10, and 10 interlaces may exist within one RBS. Furthermore, the number of RBs associated with one interlace index may be 10 (100 RBs / 20 MHz). Here, a case where the number of PSCCHs is 6 may be considered. That is, as in the above-described Case 1, the number of PSCCH RBs may be smaller than the number of interlace RBs per subchannel. However, FIG. 25 is merely an example for convenience of explanation and is not limited to the above-described embodiment. Six PSCCHs may be allocated sequentially from the interlace RB 2510 having the lowest subchannel / interlace index within the PSCCH allocation resource. Since the number of interlace RBs is greater than the number of PSCCH RBs, the number of PSCCH RBs may be allocated to consecutive interlace RBs.

[0214] Here, as an example, when PSCCH resources are allocated within one RBS, PSCCH resource allocation may be performed taking into consideration at least one of the number of PSCCH RBs, the number of interlaces per subchannel (K), the number of RBs per interlace, and the number of interlaces (M). The UE may check and configure information regarding at least one of the number of PSCCH RBs, the number of interlaces per subchannel (K), the number of interlaces (M), the number of RBs per interlace, the number of PSCCH allocation units, and whether or not discontinuous PSCCH RBs are configured through higher layer parameters, which may be as shown in Table 22. The number of interlaces (M) may be determined without higher layer signaling configuration based on the SCS and RBS size associated with the SL Carrier / BWP for which the resource pool is configured, and may be as shown in Tables 19 and 20. Furthermore, if there is no configuration for the number of PSCCH allocation units, it may be set to one subchannel (or one interlace) as a default value. On the other hand, if there is a configuration for the number of PSCCH allocation units, the number of PSCCH allocation units may be determined differently depending on the configuration. Also, if there is no setting for whether or not to configure discontinuous PSCCH RBs, they can be configured based on consecutive interlace indexes / RBs as shown in Figure 25. On the other hand, if there is a setting for whether or not to configure discontinuous PSCCH RBs, they can operate based on that setting, which will be described later. Such an interlace RB allocation method can be applied and executed for each RBS.

[0215] [Table 22]

[0216] In this case, PSCCH resources may be allocated based on the upper layer parameters in Table 22 and the scheduled PSSCH frequency resources. That is, PSCCH RB allocation may be performed based on the upper layer parameters in Table 22 and the subchannel index (or interlace index). Here, PSCCH RBs may be allocated starting with the lowest subchannel index or the lowest interlace RB index associated with the lowest subchannel index. Furthermore, PSCCH RBs may be consecutively allocated to RBs of the same interlace index starting with the lowest frequency RB in the lowest interlace RB index. Here, if the number of PSCCH RBs is greater than the number of RBs in the lowest subchannel / interlace, PSCCH RBs may be allocated sequentially starting with the lowest RB in the next subchannel / interlace index, up to the number of PSCCH RBs. Furthermore, if the number of PSCCH RBs is greater than the number of interlace RBs associated with one subchannel, PSCCH RBs may be allocated following the next lowest subchannel index among the PSSCH resources scheduled in the same RBS. That is, the PSCCH may be allocated to the subchannel with the lowest index among the subchannels to which the scheduled PSSCH is allocated, taking into consideration the complexity of blind decoding of the PSCCH in the receiving terminal. However, if there is more than one subchannel allocated to the PSSCH and the number of RBs in one subchannel is less than the number of PSCCHs, the same allocation method may be used starting from the interlaced RBs in the next subchannel. Alternatively, as described above, if the PSSCH is scheduled on one or more RBSs, the PSCCH may be allocated between adjacent RBSs according to the proposed allocation method, depending on the configuration of the higher layer.

[0217] Further, as an example, the PSCCH may be transmitted within an RBS selected for scheduled PSSCH transmission. Here, the PSCCH resources may be allocated to resources corresponding to a set number of discontinuous interlaces (or RBs) starting from the lowest interlace RB included in the lowest subchannel. As an example, the PSCCH may be allocated from both ends of the RBS to the interlace RBs associated with the subchannel corresponding to the PSCCH transmission resource.

[0218] Figure 26 illustrates a method for allocating PSCCH RBs based on an interlace associated with one subchannel according to an embodiment. Referring to Figure 26, the PSCCH may be transmitted in an RBS selected for scheduled PSCCH transmission. In this case, PSCCH resources may be allocated on interlace RBs associated with a specific subchannel (e.g., the lowest subchannel index). However, the mapping order of PSCCH resources may differ from that in Figure 25. For example, to maximize PSCCH frequency diversity gain, PSCCH RBs may be allocated from both ends of the RBS frequency, taking into account the number of PSCCH RBs.

[0219] Specifically, referring to FIG. 26(a), the number of PSCCH RBs may be allocated so as to maintain equal intervals from associated interlace RBs located at both ends of the frequency band based on a specific subchannel index within an RBS (hereinafter, referred to as Alternative 1). As another example, referring to FIG. 26(b), the number of PSCCH RBs may be allocated to consecutive interlace RBs, starting with associated interlace RBs located at both ends of the frequency band based on a specific subchannel index within an RBS (hereinafter, referred to as Alternative 2). That is, compared to FIG. 25, FIG. 26 does not allocate PSCCHs to RBs within consecutive interlaces, and the allocation order of interlace RBs within one subchannel may be set differently to maximize PSCCH frequency diversity gain. Other settings may be the same as FIG. 25. In this case, if the number of subchannels allocated to the PSCCH is greater than one and the number of RBs in one subchannel is less than the number of PSCCHs, the PSCCH may be further allocated from the interlace RBs in the next subchannel according to the scheme of FIG. 26.

[0220] The above describes a method for allocating a PSSCH in the frequency domain. Here, the number of OFDM symbols used for PSCCH transmission in the time domain can be determined for each PSCCH transmission slot by configuration from a higher layer. Furthermore, the starting OFDM symbol position for PSCCH allocation in the time domain may always be allocated starting from the second symbol for the set number of symbols, regardless of whether an AGC symbol is present. As another example, the starting OFDM symbol position for PSSCH transmission may be flexibly changed for each slot depending on whether an AGC symbol is present. As a specific example, if an AGC symbol is not present in a slot, PSCCH transmission may be allocated starting from the first OFDM symbol of the slot. For example, in a situation where PSSCH / PSCCH transmission is performed through consecutive slots in a sidelink on an unlicensed band, the presence or absence of an AGC symbol may be signaled and changed. In consideration of the above, the PSCCH allocation in the time domain may also be changed as described above.

[0221] Furthermore, the starting OFDM position of the PSCCH transmission symbol can be determined depending on whether sub-slot-based sidelink transmission / reception (sub-slot based SL communication) is applied. That is, unlike the existing sidelink transmission / reception architecture that performs slot-based sidelink transmission / reception, when data transmission / reception is applied in sub-slot units to the sidelink unlicensed spectrum (SL-U), PSCCH / PSSCH transmission can be performed from the middle of the sidelink slot or from a specific OFDM symbol index. In this case, the PSCCH starting OFDM symbol may also be determined and used as a specific OFDM symbol depending on the results of the above-mentioned configuration, scheduling, and LBT.

[0222] Here, the PSCCH transmission method in the time domain can be applied together with the above-mentioned PSCCH transmission method in the frequency domain and is not limited to a specific PSCCH transmission method. That is, the PSCCH transmission method in the time domain is not limited to a specific method among the above-mentioned PSCCH transmission methods in the frequency domain and can be applied together with each PSCCH transmission method in the frequency domain.

[0223] Second SCI mapping method

[0224] FIG. 27 illustrates an SL channel according to an embodiment. Referring to FIG. 27(a), the first SCI may be transmitted over a PSCCH. Conversely, referring to FIG. 27(b), the second SCI may be allocated and transmitted within PSSCH resources together with SL-SCH (SL Data). Referring to FIG. 27(c), HARQ feedback may be transmitted over a PSFCH, and referring to FIG. 27(d), S-MIB may be transmitted over a PSBCH. Here, the second SCI may not be allocated to resources allocated to other signals for SL transmission and reception (e.g., SL CSI-RS, PT-RS, DMRS, SL Sync. Signal, PSBCH, PSFCH, PSCCH). The second SCI mapping may be performed taking into consideration the above-described PSSCH / PSCCH allocation method. For example, the second SCI may be transmitted within an RBS determined for the PSCCH, or may be transmitted based on at least one of the same subchannel and interlace RB. Here, the second SCI may be allocated to a specific resource within a physical resource region where the PSSCH is scheduled, rather than being allocated to the same resource element (RE). For example, the second SCI may not be allocated to resources allocated to DMRS, PT-RS, CSI-RS, or PSCCH for the sidelink within one slot, as described above. Therefore, allocation may be performed within the remaining resource region within the physical resource region determined for PSSCH transmission, excluding the resource region allocated to DMRS, PT-RS, or PSCCH. That is, the second SCI may be allocated and transmitted together with the PSCCH on the same resource as the RBS, subchannel, or interlace RB to which the PSCCH is allocated.

[0225] For example, the second SCI may be allocated within the remaining scheduling resources based on an allocation method within a subchannel associated with the PSCCH allocation method. Specifically, the second SCI may be allocated starting from the first PSSCH symbol and starting from a scheduled resource index, starting from REs excluding resources used for associated DMRS, PT-RS, CSI-RS, or PSCCH transmission. That is, the second SCI may be allocated starting from REs excluding REs within an interlace RB used for associated DMRS, PT-RS, CSI-RS, or PSCCH transmission. Here, the second SCI resource allocation may be allocated by different methods within a subchannel or interlace RB, taking into account at least one of the PSCCH, associated DMRS, PT-RS, or CSI-RS allocation method, and CRB-interlace-subchannel frequency configuration.

[0226] Figure 28 illustrates a method for allocating second SCI resources according to an embodiment. Referring to Figure 28, the PSCCH (first SCI) may be allocated starting from the lowest interlace RB associated with a subchannel corresponding to the lowest subchannel index within the scheduled resources. In this case, the PSCCH may be allocated sequentially by the number of consecutive interlace RB indexes according to the number of PSCCH RBs. Here, if there are interlace RBs and REs to which no PSCCH is allocated in the same OFDM symbol, the second SCI may be allocated starting from the corresponding resource. The second SCI may also be allocated in the order of interlace RBs within the sequentially associated subchannels, starting from the aforementioned resource. That is, it may be allocated in the direction from low-frequency REs to high-frequency REs.

[0227] 29 and 30 are diagrams illustrating a second SCI resource allocation method according to an embodiment.

[0228] 29 and 30, PSCCH allocation may be performed based on the above-described Method 2. As an example, PSCCH resources may be allocated sequentially from both ends of the frequency band starting with the lowest subchannel index / lowest interlace index within the scheduled resources. If RBs / REs for second SCI allocation exist within the same subchannel / interlace / OFDM symbol to which the PSCCH is allocated on the physical resources on which the PSCCH is scheduled, the second SCI may be allocated starting with the lowest frequency RB / RE among the RBs / REs. Then, the second SCI may be allocated sequentially in the order of the next OFDM symbol. Here, the second SCI allocation method may be based on either Method 1 or Method 2, which are the allocation methods proposed for the PSCCH allocation, starting with the first RB / RE in the first OFDM symbol within the scheduled physical resources.

[0229] As a specific example, referring to FIG. 29, the PSCCH may be allocated sequentially from both ends of the frequency band starting with the lowest subchannel index / lowest interlace index within the scheduled resources. Conversely, the second SCI may be allocated sequentially from both ends of the frequency band starting with the lowest subchannel index / lowest interlace index within the resources where the PSCCH is scheduled. Also, referring to FIG. 30, both the PSCCH and the second SCI may be allocated sequentially from both ends of the frequency band starting with the lowest subchannel index / lowest interlace index within the resources where the PSCCH is scheduled. For example, after the PSCCH is allocated starting with the lowest subchannel index / lowest interlace index according to one of the proposed methods, transmission can be performed on resources within that index available in the same or the next OFDM symbol for the second SCI allocation.

[0230] Also, Figure 31 illustrates a method for allocating a second SCI according to an embodiment. Referring to Figure 31, only time division multiplexing (TDM) can be applied to the PSCCH allocation and the second SCI allocation. Here, the second SCI may be allocated within resources scheduled from OFDM symbols after the PSCCH is allocated. Here, the second SCI allocation may be performed based on any of the methods described above for PSCCH allocation.

[0231] As another example, a case may be considered in which the PSCCH and the second SCI are allocated to multiple subchannels. For example, the PSCCH may be allocated to multiple subchannels based on a configuration by a higher layer or a predetermined setting. Here, FIG. 32 illustrates a method of allocating the second SCI based on multiple subchannels according to an embodiment. Referring to FIG. 32, for PSCCH allocation, allocation may be performed for the number of RBs corresponding to the PSCCH interlace indexes in two subchannels. Referring to FIG. 32, subchannel #0 and subchannel #1 may be considered within the scheduled PSSCH resource region. In this case, frequency domain allocation may be performed sequentially from the lowest subchannel index and the lowest interlace RB index starting from the first OFDM symbol, and then time domain allocation may be performed. Here, two methods may be considered for allocating the PSCCH to two subchannels in the frequency domain. First, as an example, a method may be considered in which a subchannel index is allocated first, and then the next subchannel index / interlace RB index resource is allocated. That is, the PSCCH and second SCI resources may be allocated to the lowest subchannel index / interlace RB index within the scheduled PSSCH resource region. Then, the PSCCH and second SCI resources may be allocated in the order corresponding to the subchannel index / interlace RB index. That is, the PSCCH and second SCI resources may be allocated starting from the resources corresponding to the lowest subchannel index #0 / interlace RB index #0 among the scheduled subchannels, and if RBs for additional PSCCH allocation remain, the PSCCH and second SCI resources may be allocated starting from the resources corresponding to the next subchannel, subchannel #1 / interlace RB index #1.

[0232] As another example, the PSCCH and the second SCI may be preferentially allocated to resources corresponding to corresponding subchannel indexes / interlace RB indexes based on the lowest frequency resource. That is, they may be allocated starting from the lowest subchannel index / interlace RB index within the scheduled PSSCH resource region. However, the PSCCH and second SCI resource allocation may be allocated in the order of multiple subchannels / interlace RBs, which are PSCCH resource allocation units, starting from the lowest frequency resource in the frequency domain, rather than in the order of resources corresponding to subchannels or interlace RBs. Specifically, referring to FIG. 32, the PSCCH allocation may be preferentially allocated starting from the lowest subchannel index #0 within the scheduled resource region (subchannel #0 / 1). That is, allocation may be sequentially performed to physical resources corresponding to the lowest two subchannel indexes corresponding to the PSCCH allocation, starting from the lowest RB / RE index in terms of the frequency domain.

[0233] FIG. 33 is a flowchart illustrating a PSCCH resource allocation method applied to the present disclosure.

[0234] Referring to FIG. 33, a terminal may acquire resource information for a sidelink unlicensed band of one carrier bandwidth (S3310). Here, resource pool information for the sidelink unlicensed band may be provided to the terminal based on at least one of RBS configuration / index information and interlace / subchannel-based configuration information. Then, a sidelink unlicensed band resource pool may be configured based on the resource pool configuration information for the sidelink unlicensed band (S3320). Here, at least one RBS may be configured in the resource pool of the SL unlicensed band, and the success or failure of the LBT for each RBS may be confirmed (S3330). Then, PSCCH resources may be allocated to at least one RBS that has successfully completed the LBT, and PSCCH transmission may be performed (S3340). Here, the PSCCH resources may be allocated to only one RBS as a specific RBS among the at least one RBS that has successfully completed the LBT. For example, the specific RBS may be an RBS with the lowest RBS index among the at least one RBS that has successfully completed the LBT, but this is not limited to a specific embodiment. That is, the PSCCH resource can be included in only one of the RBSs that have been successfully subjected to LBT, thereby preventing an increase in blind decoding and power consumption.

[0235] As another example, a PSCCH resource may be allocated to each of at least one or more RBSs that have successfully passed the LBT. As an example, a PSCCH resource may be determined based on one RBS, and the same PSCCH may be allocated to other RBSs through PSCCH duplication, thereby preventing an increase in blind decoding and power consumption.

[0236] FIG. 34 is a flowchart illustrating a PSCCH resource allocation method applied to the present disclosure.

[0237] Referring to FIG. 34, a UE may acquire resource information for a sidelink unlicensed band of one carrier bandwidth (S3410). Here, resource pool information for the sidelink unlicensed band may be provided to the UE based on at least one of RBS configuration / index information and interlace / subchannel-based configuration information. For example, the resource pool for the sidelink unlicensed band may be configured as interlace-based RB resources in consideration of a mapping relationship between CRBs and sidelink interlace indexes. Furthermore, the corresponding sidelink interlace(s) may be mapped to subchannels. Then, a sidelink unlicensed band resource pool may be configured based on the resource pool configuration information for the sidelink unlicensed band (S3420). Here, at least one RBS may be configured in the resource pool for the SL unlicensed band, and the success or failure of LBT for each RBS may be confirmed. In addition, the UE may confirm the number of PSCCH RBs, the number of interlaces per subchannel (K), and the number of interlaces (M) based on higher layer parameters (S3430). Furthermore, the terminal may check at least one of the number of PSCCH allocation units and whether discontinuous PSCCH RBs are configured based on higher layer parameters. Here, if there is no configuration for the number of PSCCH allocation units, the PSCCH may be allocated to one subchannel (or one interlace) based on the number of PSCCH allocation units, as described above. Furthermore, as an example, depending on whether discontinuous PSCCH RBs are configured, PSCCH RBs may be allocated contiguously or discontinuously to interlace RBs associated with one subchannel, as described above. Here, if there is no configuration for discontinuous PSCCH RBs, the PSCCH RBs may be configured to be allocated contiguously to interlace RBs associated with one subchannel as a default configuration, but this is not limited to this. PSCCH resources may be allocated starting from the lowest interlace RB index included in the lowest subchannel index within an RBS that has successfully completed LBT.That is, the terminal may allocate PSCCH resources from a specific interlace RBS index included in a specific subchannel index within an RBS determined based on the higher layer parameters and whether the LBT is successful (S3440). As an example, an RBS for sidelink communication may be determined within a resource pool based on whether the LBT is successful. Here, PSCCH resources may be allocated from a specific interlace RBS index included in the lowest subchannel index within an RBS determined based on the higher layer parameters and whether the LBT is successful. As another example, PSCCH resources may be allocated from a specific interlace RBS index included in the highest subchannel index or any subchannel index within an RBS determined based on the higher layer parameters and whether the LBT is successful, and this is not limited to a specific embodiment.

[0238] As another example, PSCCH resources may be allocated to resources corresponding to discontinuous interlace numbers starting from the lowest interlace RB index included in the lowest subchannel index within an RBS. For example, PSCCH resources may be allocated to maintain equal intervals from associated interlace RBs located at both ends of the frequency band based on a specific subchannel index within an RBS. As another example, PSCCH resources may be allocated to consecutive interlace RBs starting from associated interlace RBs located at both ends of the frequency band based on a specific subchannel index within an RBS, as described above.

[0239] FIG. 35 is a diagram showing a base station apparatus and a terminal apparatus to which the present disclosure can be applied.

[0240] The base station device 3500 may include a processor 3520 , an antenna unit 3512 , a transceiver 3214 , and a memory 3516 .

[0241] The processor 3520 performs baseband-related signal processing and may include an upper layer processing unit 3530 and a physical layer processing unit 3540. The upper layer processing unit 3530 may process operations of a medium access control (MAC) layer, a radio resource control (RRC) layer, or higher layers. The physical layer processing unit 3540 may process operations of a physical (PHY) layer (e.g., uplink receive signal processing, downlink transmit signal processing). In addition to performing baseband-related signal processing, the processor 3520 may control the overall operation of the base station device 3500.

[0242] The antenna unit 3512 may include one or more physical antennas, and when multiple antennas are included, it may support MIMO (Multiple Input Multiple Output) transmission and reception, and may also support beamforming.

[0243] The memory 3516 can store information processed by the processor 3520, software associated with the operation of the base station device 3500, an operating system, applications, etc., and can include components such as buffers.

[0244] The processor 3520 of the base station device 3500 may be configured to perform the operations of the base station in the embodiments described herein.

[0245] The terminal device 3550 may include a processor 3570, an antenna unit 3562, a transceiver 3564, and a memory 3566. As an example, in the present invention, the terminal device 3550 can communicate with the base station device 3500. As another example, in the present invention, the terminal device 3550 can perform sidelink communication with another terminal device. That is, the terminal device 3550 of the present invention refers to a device that can communicate with at least one of the base station device 3500 and another terminal device, and is not limited to communication with a specific device.

[0246] The processor 3570 performs baseband-related signal processing and may include an upper layer processing unit 3580 and a physical layer processing unit 3590. The upper layer processing unit 3580 may process operations of the MAC layer, the RRC layer, or higher layers. The physical layer processing unit 3590 may process operations of the PHY layer (e.g., downlink receive signal processing, uplink transmit signal processing). In addition to performing baseband-related signal processing, the processor 3570 may control the overall operation of the terminal device 3550.

[0247] The antenna unit 3562 may include one or more physical antennas, and when multiple antennas are included, may support MIMO transmission and reception, and may also support beamforming.

[0248] The memory 3566 can store information processed by the processor 3570, software associated with the operation of the terminal device 3550, an operating system, applications, etc., and can include components such as buffers.

[0249] A terminal device 3550 according to an embodiment of the present invention may be associated with a vehicle. For example, the terminal device 3550 may be built into, located in, or located on the vehicle. The terminal device 3550 according to the present invention may also be the vehicle itself. The terminal device 3550 according to the present invention may be at least one of a wearable terminal, an AV / VR terminal, an IoT terminal, a robot terminal, and a public safety terminal. The terminal device 3550 to which the present invention is applicable may include any of various types of communication devices that support interactive services using a sidelink for services such as Internet connection, service execution, navigation, real-time information, autonomous driving, safety, and hazard diagnosis. The terminal device 3550 may also include any type of communication device that functions as an AR / VR device capable of sidelink operation or a sensor that performs a relay operation.

[0250] Here, vehicles to which the present invention is applied may include autonomous vehicles, semi-autonomous vehicles, non-autonomous vehicles, etc. Meanwhile, although the terminal device 3550 according to an example of the present invention is described as being associated with a vehicle, one or more of the UEs may not be associated with a vehicle. This is merely an example, and the application of the present invention should not be construed as being limited by the described example.

[0251] In addition, the terminal device 3550 according to an embodiment of the present invention may include various types of communication devices capable of cooperating to support an interactive service using a sidelink. That is, the terminal device 3550 may not only directly support an interactive service using a sidelink, but also be used as a cooperating device to support an interactive service using a sidelink.

[0252] Further, as an example, the terminal device 3550 may acquire resource information for a sidelink unlicensed band of one carrier bandwidth. Here, resource pool information for the sidelink unlicensed band may be provided to the terminal device 3550 based on at least one of RBS configuration / index information and interlace / subchannel-based configuration information. Then, a sidelink unlicensed band resource pool may be configured based on the resource pool configuration information for the sidelink unlicensed band. Here, at least one RBS may be configured in the resource pool of the SL unlicensed band, and the success or failure of the LBT for each RBS may be confirmed. Then, PSCCH resources may be allocated to at least one RBS for which the LBT has been successful, and PSCCH transmission may be performed. Here, the PSCCH resource may be allocated to only one RBS as a specific RBS among the at least one RBS for which the LBT has been successful. For example, the specific RBS may be an RBS with the lowest RBS index among the at least one RBS for which the LBT has been successful, but this is not limited to a specific embodiment. That is, the PSCCH resource may be included in only one RBS among the RBSs for which the LBT has been successful, thereby preventing an increase in blind decoding and power consumption.

[0253] As another example, a PSCCH resource may be allocated to each of at least one or more RBSs that have successfully passed the LBT. As an example, a PSCCH resource may be determined based on one RBS, and the same PSCCH may be allocated to other RBSs through PSCCH duplication, thereby preventing an increase in blind decoding and power consumption.

[0254] The terminal device 3550 may acquire resource information regarding a sidelink unlicensed band of one carrier bandwidth. Here, resource pool information for the sidelink unlicensed band may be provided to the terminal device 3550 based on at least one of RBS configuration / index information and interlace / subchannel-based configuration information. For example, the resource pool of the sidelink unlicensed band may be configured as interlace-based RB resources in consideration of a mapping relationship between CRBs and sidelink interlace indexes. Furthermore, the corresponding sidelink interlace(s) may be mapped to subchannels. Then, a sidelink unlicensed band resource pool may be configured based on the resource pool configuration information of the sidelink unlicensed band. Here, at least one RBS may be configured in the resource pool of the SL unlicensed band, and the success or failure of LBT for each RBS may be confirmed. Furthermore, the terminal device 3550 may confirm the number of PSCCH RBs, the number of interlaces per subchannel (K), and the number of interlaces (M) based on higher layer parameters. Furthermore, the terminal device 3550 may confirm at least one of the number of PSCCH allocation units and whether non-contiguous PSCCH RBs are configured based on higher layer parameters. Here, if there is no configuration for the number of PSCCH allocation units, the PSCCH may basically be allocated within one subchannel (or one interlace), as described above. Furthermore, as an example, depending on whether discontinuous PSCCH RBs are configured, PSCCH RBs may be allocated contiguously or discontinuously to interlace RBs associated within one subchannel, as described above. Here, if there is no configuration for discontinuous PSCCH RBs, the PSCCH RBs may be configured to be allocated contiguously to interlace RBs associated within one subchannel as a default configuration, but this is not limited to this. PSCCH resources may be allocated starting from the lowest interlace RB index included in the lowest subchannel index within an RBS that has successfully completed LBT.That is, the terminal device 3550 may allocate PSCCH resources from a specific interlace RBS index included in a specific subchannel index within an RBS determined based on the higher layer parameters and whether the LBT is successful. As an example, an RBS for sidelink communication may be determined within a resource pool based on the success or failure of the LBT. Here, PSCCH resources may be allocated from a specific interlace RBS index included in the lowest subchannel index within an RBS determined based on the higher layer parameters and whether the LBT is successful. As another example, PSCCH resources may be allocated from a specific interlace RBS index included in the highest subchannel index or any subchannel index within an RBS determined based on the higher layer parameters and whether the LBT is successful, and this is not limited to a specific embodiment.

[0255] As another example, PSCCH resources may be allocated to resources corresponding to discontinuous interlace numbers starting from the lowest interlace RB index included in the lowest subchannel index within an RBS. For example, PSCCH resources may be allocated to maintain equal intervals from associated interlace RBs located at both ends of the frequency band based on a specific subchannel index within an RBS. As another example, PSCCH resources may be allocated to consecutive interlace RBs starting from associated interlace RBs located at both ends of the frequency band based on a specific subchannel index within an RBS, as described above.

[0256] Furthermore, various embodiments of the present disclosure may be implemented using hardware, firmware, software, or a combination thereof, etc. In the case of a hardware implementation, the implementation may be using one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), general processors, controllers, microcontrollers, microprocessors, etc.

[0257] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that cause the operations of the methods of the various embodiments to be performed on a device or computer, as well as non-transitory computer-readable media on which such software or instructions are stored and which can be executed on a device or computer.

[0258] The various embodiments of the present disclosure do not enumerate all possible combinations, but are intended to describe representative aspects of the present disclosure, and the matters described in the various embodiments may be applied independently or in combination of two or more. [Industrial Applicability]

[0259] The above may also be applied to other systems.

Claims

1. 1. A method for configuring a sidelink resource pool in a terminal in a wireless communication system, comprising: The terminal receives resource pool configuration information from a base station based on higher layer signaling; determining whether channel occupation of at least one resource block set (RBS) in the resource pool is successful based on the resource pool configuration information; allocating physical sidelink control channel (PSCCH) resources in the at least one RBS based on whether the channel occupation is successful, and performing PSCCH transmission; performing sidelink communication with the other terminal.

2. 2. The method of claim 1, wherein, if the PSCCH resources are allocated to at least one RBS that has successfully occupied the channel based on whether the channel occupation is successful, the PSCCH resources are allocated to only one of the at least one RBS that has successfully occupied the channel.

3. If the PSCCH resource is allocated to at least one RBS that has successfully occupied the channel based on whether the channel occupation is successful, the PSCCH resource is allocated to each of the at least one RBS that has successfully occupied the channel; The method of claim 1, wherein the PSCCH is duplicated and assigned to each of at least one RBS that has successfully occupied the channel.

4. 2. The method of claim 1, wherein when the PSCCH resources are allocated in the at least one RBS, the PSCCH resources are allocated to resources corresponding to a set number of consecutive interlaces starting from the lowest interlace RB included in the lowest subchannel in the RBS.

5. 2. The sidelink resource pool configuration method according to claim 1, wherein when the PSCCH resources are allocated in the at least one RBS, the PSCCH resources are allocated to resources corresponding to a set number of discontinuous interlaces starting from the lowest interlace RB included in the lowest subchannel in the RBS.

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