Method and apparatus for performing sidelink communications over unlicensed spectrum

Abstract

A wireless user device operating in a sidelink unlicensed band in a wireless communication system includes at least one antenna for transmitting and receiving one or more wireless signals, at least one processor, and a memory for storing instructions for the wireless user device when executed by the at least one processor, wherein operations of the wireless user device can include: determining a number of OFDM symbols available for PSSCH transmission, determining a number of coded symbols of a 2nd SCI based on the number of OFDM symbols available for PSSCH transmission, determining a number of resource elements of the 2nd SCI based on the number of coded symbols of the 2nd SCI, and mapping the 2nd SCI to a radio resource based on a starting OFDM symbol position related parameter and an OFDM symbol number related parameter, and transmitting the mapping to another wireless user device.

Description

[Technical Field]

[0001] The present invention relates to a rate matching method and apparatus for transmitting and receiving a data channel in a sidelink unlicensed band (SL-U) in a wireless communication system. [Background technology]

[0002] The International Telecommunication Union (ITU) is developing the International Mobile Telecommunication (IMT) framework and standards, and has recently been discussing fifth-generation (5G) communications 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] In addition, discussions are underway on how to support seamless communication services at the service level for mobile terminals (e.g., vehicles, trains, ship-type terminals, and personally owned smartphones) using not only terrestrial networks (TN) but also non-terrestrial networks (NTN) in new communication systems. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention relates to a rate matching method and apparatus for transmitting and receiving data channels in SL-U of a wireless communication system.

[0006] The present invention relates to a rate matching method and apparatus for allocating second SCI (sidelink control information) in SL-U.

[0007] The present invention relates to a method and apparatus for determining the number of coded symbols for the 2nd SCI in an SL-U.

[0008] The present invention relates to a rate matching method and apparatus for allocating a second SCI based on a slot in which a physical sidelink feedback channel (PSFCH) exists in SL-U. [Means for solving the problem]

[0009] According to one embodiment, a wireless user device operating in a sidelink unlicensed band in a wireless communication system includes at least one antenna for transmitting and receiving one or more radio signals, at least one processor, and a memory for storing instructions for the wireless user device when executed by the at least one processor, wherein operations of the wireless user device can include: determining a number of orthogonal frequency division multiplexing (OFDM) symbols available for PSSCH (physical sidelink shared channel) transmission; determining a number of coded symbols of a second SCI (sidelink control information) based on the number of OFDM symbols available for PSSCH transmission; determining a number of resource elements (REs) for the second SCI based on the number of coded symbols of the second SCI; and mapping the second SCI to radio resources based on a starting OFDM symbol position related parameter and an OFDM symbol number related parameter, and transmitting the mapping to another wireless user device.

[0010] Furthermore, in one embodiment, the number of OFDM symbols available for PSSCH transmission is determined as a value of sidelink length symbols (SL-lengthSymbols) minus gap symbols, and the value of sidelink length symbols may be determined based on higher layer parameters and / or SCI signaling.

[0011] Furthermore, according to one embodiment, the gap symbols may be determined based on higher layer parameters and / or SCI signaling.

[0012] Furthermore, according to one embodiment, the gap symbols may be implicitly determined based on the starting OFDM symbol position and the number of OFDM symbols determined based on the time when the wireless user equipment has successfully completed listen before talk (LBT).

[0013] Furthermore, according to one embodiment, the number of coded symbols of the 2nd SCI may be determined by further reflecting the number of physical sidelink feedback channel (PSFCH) symbols in addition to the number of OFDM symbols available for PSSCH transmission.

[0014] Also, according to one embodiment, the number of PSFCH symbols may be determined as a specific value based on a PSFCH overhead indication field in the SCI, and if the PSFCH overhead indication field in the SCI indicates the presence of a PSFCH, the number of PSFCH symbols may be determined as a first value, and if the PSFCH overhead indication field in the SCI indicates the absence of a PSFCH, the number of PSFCH symbols may be determined as 0.

[0015] Furthermore, according to one embodiment, the number of resource elements of the 2nd SCI may be determined based on the number of subcarriers associated with PSSCH transmission and the number of subcarriers on the OFDM symbol to which the PSCCH (physical sidelink control channel) and the PSCCH DMRS (demodulation reference signal) associated with the PSSCH are assigned.

[0016] Furthermore, according to one embodiment, when a sidelink-synchronization signal block (SL-SSB) is multiplexed with a physical sidelink control channel (PSSCH / PSCCH) based on a sidelink unlicensed band, the number of resource elements of the 2nd SCI may be determined further based on the number of SL-SSB resource elements. [Effects of the Invention]

[0017] According to the present disclosure, a rate matching method for transmitting and receiving data channels in the SL-U of a wireless communication system can be provided.

[0018] According to the present disclosure, a rate matching method for 2nd SCI allocation in SL-U can be provided.

[0019] According to the present disclosure, a method for determining the number of coded symbols for the 2nd SCI in the SL-U can be provided.

[0020] According to the present disclosure, a rate matching method for allocating a second SCI based on the slot in which the PSFCH exists in the SL-U can be provided.

[0021] The present disclosure is not limited to the above-mentioned effects, and other effects not mentioned herein will be clearly understood by those skilled in the art to which the present disclosure pertains from the following description. [Brief explanation of the drawings]

[0022] [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 a method for configuring a resource pool for a sidelink unlicensed band to which the present disclosure can be applied. [Figure 18] FIG. 18 illustrates a frequency resource-based sidelink unlicensed band resource pool configuration using interlace allocation to which the present disclosure can be applied. [Figure 19] FIG. 19 illustrates a sidelink unlicensed band resource pool configuration method to which the present disclosure can be applied. [Figure 20] FIG. 20 is a diagram illustrating a method for configuring multiple starting symbols and symbol lengths for PSCCH and PSSCH transmission to which the present disclosure may be applied. [Figure 21] FIG. 21 illustrates a rate matching method based on indication of the presence or absence of AGC / gap symbols to which the present disclosure may be applied. [Figure 22] FIG. 22 illustrates a method for transmitting sidelink data based on mid-slot LBT success to which the present disclosure can be applied. [Figure 23] FIG. 23 is a diagram illustrating a SL non-slot-based PSFCH transmission method in SL-U to which the present disclosure can be applied. [Figure 24] FIG. 24 illustrates a method for scheduling multiple TTIs through one SCI signaling to which the present disclosure can be applied. [Figure 25] FIG. 25 illustrates a method for applying multiplexing between SL SSBs and PSSCH / PSCCH to which the present disclosure may be applied. [Figure 26] FIG. 26 is a diagram illustrating a case where an additional SL-SSB occasion to which the present disclosure can be applied is configured in a resource pool. [Figure 27] FIG. 27 is a diagram illustrating a method for performing non-slot-based sidelink transmission including a 2nd SCI after a successful LBT to which the present disclosure can be applied. [Figure 28] FIG. 28 is a diagram illustrating a method for performing non-slot and slot-based sidelink transmission including a 2nd SCI after a successful LBT to which the present disclosure can be applied. [Figure 29] FIG. 29 is a flowchart illustrating the operation of a wireless user equipment (UE) operating in a sidelink unlicensed band to which the present disclosure may be applied. [Figure 30] FIG. 30 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

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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).

[0034] 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.

[0035] First, a brief description will be given of the physical resource structure of the NR system to which the present invention is applied.

[0036] FIG. 1 is a diagram for explaining an NR frame structure to which the present disclosure can be applied.

[0037] 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.

[0038] 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.

[0039] 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:

[0040]

number

[0041] 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 can be 39936Tc or 25600Tc. 39936Tc is 20.327μs, and 25600Tc is 13.030μs. Also, in FR2 (Frequency Range 2), which is a millimeter wave (mmWave) frequency, N TA,offset can be 13792Tc, where 39936Tc is 7.020μs.

[0042] FIG. 2 is a diagram illustrating an NR resource structure to which the present disclosure may be applied.

[0043] 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.

[0044] In the frequency domain, one resource block (RB) consists of 12 REs, and an index (nPRB ) 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.

[0045]

number

[0046] 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.

[0047] 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.

[0048] Table 1 below shows examples of pneumoradio supported by the NR system.

[0049] [Table 1]

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] 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).

[0056] [Table 2]

[0057] Table 2 shows the number of OFDM symbols per slot (N 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.

[0058] [Table 3]

[0059] 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.

[0060] 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.

[0061] [Table 4]

[0062] 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.

[0063] 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. To this end, new features can 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.

[0064] 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.

[0065] [Table 5-1] [Table 5-2]

[0066] 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.

[0067] 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.

[0068] Here, NR V2X capability is not necessarily limited to supporting only V2X services, and may optionally support the use of a certain V2X RAT.

[0069] 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).

[0070] 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.

[0071] 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.

[0072] FIG. 3 is a diagram illustrating an NR sidelink slot structure to which the present disclosure can be applied.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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).

[0077] 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.

[0078] 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.

[0079] [Table 6]

[0080] [Table 7-1] [Table 7-2] [Table 7-3]

[0081] Next, the sidelink HARQ procedure will be described. Whether a V2X UE reports HARQ feedback is indicated by higher layer (e.g., RRC) configuration and SCI signaling (e.g., secondary SCI). For example, when a V2X UE performs communication based on groupcast, it can determine whether to report HARQ feedback based on the distance between the transmitting UE and the receiving UE.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] [Table 8]

[0089] 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.

[0090] 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 a multiple of the length of the bitmap on the time resource (e.g., sl-TimeResource) is not established, and does not need to be used as an NR sidelink resource.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] [Table 9]

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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 JPEG2026508064000016.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. As an 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, may recognize the CRB position in the frequency domain. Here, each guard band is provided with a starting CRB. JPEG2026508064000017.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. JPEG2026508064000019.jpg966, JPEG2026508064000020.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.

[0106] 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.

[0107] Here, each RBS can be defined as a start CRB and an end CRB. The start CRB is JPEG2026508064000022.jpg1326 and the end CRB is JPEG2026508064000023.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 interference with wireless bandwidth is permitted by JPEG2026508064000024.jpg1322.

[0108] 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 JPEG2026508064000025.jpg971. That is, the RBS index s is JPEG2026508064000026.jpg may be a resource block having a size of 1323, JPEG2026508064000027.jpg1323 is the number of CRBs determined through the start CRB and end CRB based on Equation 3. Also, the start CRB and end CRB for each RBS may be as shown in Equation 4 and Equation 5.

[0109]

number

[0110]

number

[0111]

number

[0112] 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 JPEG2026508064000031.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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] [Table 10]

[0119] 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.

[0120] [Table 11]

[0121] 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.

[0122] 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.

[0123] 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.

[0124] [Table 12]

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] [Table 13]

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] [Table 14]

[0135] 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.

[0136] [Table 15]

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] [Table 16]

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] Here, as an example, FIG. 17 illustrates a method for configuring a sidelink unlicensed band resource pool based on contiguous frequency resources to which the present disclosure is applied. Referring to FIG. 17, the sidelink unlicensed band resource pool 1710 may also be configured based on contiguous frequency resources. In this case, the sidelink unlicensed band resource pool 1710 may be indicated only by an RBS index. More specifically, referring to FIG. 17, a case may be considered in which only one RBS 1720 is configured in the sidelink unlicensed band resource pool 1710 in consideration of the LBT procedure for the unlicensed band. Here, the sidelink unlicensed band resource pool configuration may be instructed to the UE based on contiguous frequency resources from a frequency domain perspective (hereinafter, referred to as Case 1). As an example, to satisfy the above-mentioned requirements such as OCB and PSD on the unlicensed band, most frequency resources (e.g., >80%) in at least one LBT BW (RBS 1720) may be configured in one resource pool. Considering the above-mentioned provisions, there may be a limit to configuring more than one resource pool for one RBS in one SL BWP. That is, since only one resource pool exists in one RBS, it can be configured to include most of the frequency resources, thereby satisfying the above-mentioned regulations. In this case, for example, sidelink transmission can be performed by selecting resources to be used for actual transmission through interlace-based frequency resource allocation in a resource pool configured on a contiguous frequency resource basis.

[0156] On the other hand, Figure 18 illustrates frequency resource-based sidelink unlicensed band resource pool configuration using interlace allocation to which the present disclosure is applied. Referring to Figure 18, in order to satisfy the regulations on frequency utilization in the unlicensed band, a resource pool can be configured using new interlace RBs or interlace RB-based subchannels from the initial resource pool configuration step. That is, interlace RBs or interlace RB-based subchannels can be used from the resource pool configuration. As an example, referring to Figure 18, when configuring a frequency resource-based sidelink unlicensed band resource pool using interlace allocation, frequency resources for the resource pool configuration can be indicated based on a combination of RBSs and interlace / subchannel indexes (hereinafter referred to as Case 2).

[0157] That is, in Figure 18, resource pools 1821 and 1822 can be configured using interlaced RBs or interlaced RB-based subchannels from the initial resource pool configuration step to satisfy requirements such as OCB and PSD. Therefore, the sidelink unlicensed band resource pools 1821 and 1822 do not need to have contiguous subchannels or PRB structures. That is, the sidelink unlicensed band resource pools 1821 and 1822 can be configured with non-contiguous PRBs based on interlaced allocation, thereby satisfying requirements such as OCB and PSD. Furthermore, unlike Case 1 (Figure 17), multiple sidelink unlicensed band resource pools can be configured within one RBS, thereby providing flexibility in resource configuration.

[0158] Here, the resource pool configuration methods corresponding to the above-mentioned Case 1 and Case 2 can both consider an interlace-based frequency resource allocation method. However, there may be a difference in whether the frequency resources are configured as contiguous frequency resources similar to the existing NR SL in the step of configuring one resource pool (Case 1), or whether a discontinuous resource pool is configured taking into account the interlace structure from the resource pool configuration step (Case 2). Based on the above, an RBS-based sidelink unlicensed band resource pool configuration method will be described below.

[0159] FIG. 19 illustrates a sidelink unlicensed band resource pool configuration method applicable to the present disclosure.

[0160] The sidelink unlicensed band resource pool can be configured based on the RBS. For example, the sidelink resource pool can be configured based on consecutive subchannels through the resource pool start point and the number of subchannels in the resource pool. For example, as described above, the sidelink unlicensed band pool can also be configured as a resource pool corresponding to an LBT BW through the resource pool start point and the number of subchannels in the resource pool based on consecutive subchannels. However, to efficiently configure the sidelink unlicensed band resource pool, the RBS setting and index can be taken into consideration. That is, the sidelink unlicensed band resource pool can be configured as one resource pool by indicating the RBS setting / index in resource pool configuration signaling.

[0161] As a specific example, a resource pool can be configured with one or more RBSs. Therefore, a specific resource pool can be configured with consecutive RBS indexes associated with the resource pool, allowing for frequency configuration for the resource pool. Here, when the frequency configuration of a resource pool is performed based on consecutive RBS indexes, the resource pool can utilize gap band resources between RBSs, thereby maximizing frequency resource efficiency. Consider the case where four RBSs are configured within one sidelink BWP. Here, a gap band can be configured between each RBS, allowing for three gap band configurations to be configured. In this case, the resource pool of the sidelink unlicensed band can be configured with consecutive RBS indexes based on the LBT BW. Specifically, frequency domain resource configuration for one resource pool configuration can be provided through RBS index information. For example, frequency domain resource configuration for one resource pool configuration can be provided through a starting RBS index and consecutive RBS number information.

[0162] Referring to FIG. 19, configuration 0 (1910) can set a resource pool to four consecutive RBSs, from RBS#0 to RBS#3. Here, configuration 0 (1910) can specify a resource pool configuration by specifying a starting RBS index, RBS#0, and the number of consecutive RBSs, four. As another example, configuration 1 (1920) can specify two consecutive RBSs, with RBS#0 and RBS#1 set to sidelink resource pool#0 and RBS#2 and RBS#3 set to sidelink resource pool#1. Here, configuration 1 can specify a resource pool configuration by specifying a starting RBS index, RBS#0 and RBS#2, and the number of consecutive RBSs, two, for each resource pool. As another example, configuration 2 (1930) can set sidelink resource pool #0 for RBS #0, sidelink resource pool #1 for RBS #1, sidelink resource pool #2 for RBS #2, and sidelink resource pool #3 for RBS #3. In this case, since each resource pool corresponds to a respective RBS, the corresponding RBS index and RBS number 1 can be indicated. As another example, configuration 3 (1940) can set sidelink resource pool #0 for RBS #0, sidelink resource pool #1 for RBS #1 and RBS #2, and sidelink resource pool #2 for RBS #3. Here, the starting RBS index and RBS number corresponding to each sidelink resource pool can be indicated, thereby indicating the configuration for each resource pool. As another example, in configuration 4 (1950), sidelink resource pool #0 can be configured for RBS #0, RBS #1, and RBS #2, and sidelink resource pool #1 can be configured for RBS #3. Here, the starting RBS index and the number of RBSs corresponding to each sidelink resource pool can be specified, thereby specifying the configuration for each resource pool.However, the resource pool configuration in FIG. 19 is merely an example and is not limited to the above-described embodiment.

[0163] In this case, as an example, if multiple RBSs are configured in the SL BWP, frequency resource information for configuring a resource pool of the sidelink unlicensed band can be indicated to the terminal through at least one of interlace / subchannel-based configuration information and RBS configuration information.

[0164] Here, when both interlace / subchannel-based configuration information and RBS configuration information are provided, frequency resource configuration information for one resource pool can be provided to a UE through intersecting frequency resource information. Also, when an intra-cell guard band (GB) existing between consecutive RBSs is configured in one resource pool, the frequency resource corresponding to the GB can also be used for sidelink unlicensed band communication as part of the resource pool.

[0165] Based on the above, a method for allocating frequency resources for sidelink unlicensed band data transmission / reception in the frequency domain will be described below. The following description is applicable to the methods for configuring a resource pool for at least one of the interlace / subchannel-based configuration information and the RBS configuration information, and is not limited to a specific embodiment.

[0166] Also, as an example, the following matters can be applied to both the case where consecutive frequency resources are configured in one resource pool (Case 1) and the case where a resource pool is configured based on discontinuous frequency resources (Case 2) in the above description. However, for convenience of explanation, the following matters will be described based on the case where one resource pool is configured based on consecutive frequency resources (Case 1), but they can also be applied interchangeably to the case where a resource pool is configured on discontinuous frequency resources (Case 2), and are not limited to a specific form.

[0167] For example, the frequency resource configuration of the sidelink unlicensed band may be configured based on consecutive frequency resources according to starting subchannel information and the number of consecutive subchannels. Also, the time resource configuration of the sidelink unlicensed band may be configured by excluding SSB transmission slots, reserved slots, and / or TDD UL-DL configuration, and then applying a bitmap to the remaining slots to configure a resource pool, and the present invention is not limited to a specific embodiment.

[0168] However, the following description will focus on frequency resource configuration for the sidelink unlicensed band. For example, the instruction for the sidelink resource set (SL RBS) index (i.e., bit size) may be configured taking into account the total number of SL RBSs included in one SL BWP. In this case, the instruction for the SL RBS index may indicate one or more SL RBS indexes. For example, the SL RBSs may be configured contiguously in the frequency domain, but this is not a limitation. However, for convenience of explanation, the following description will be based on SL RBSs configured contiguously in the frequency domain.

[0169] Further, as an example, frequency resource reservation can be indicated via a physical sidelink control channel (PSCCH). In this case, the frequency resource reservation indication can be performed in the second slot or the second / third slot based on the PSCCH received in the lowest interlace index among the interlace indexes defined within one carrier bandwidth. The interlace structure can be set to 10 interlaces (i.e., M=10) for 15 kHz SCS and 5 interlaces (i.e., M=5) for 30 kHz SCS based on the LBT BW considered in the unlicensed band, as described above. Specifically, the interlace structure can be set as described above, taking into account that the number of RBs for constituting one RBS is 100 to 110 RBs for 15 kHz SCS and 50 to 55 RBs for 30 kHz SCS based on the LBT BW.

[0170] That is, in the case of a 15 kHz SCS, a partial resource (i.e., RB) of the same interlace may exist for every 10 RBs. However, the interlace value may be configured as another value based on at least one of another RBS size (LBT BW), SCS, and the number of RBs constituting one interlace, and is not limited to a specific embodiment.

[0171] In a wireless communication system (e.g., NR), a terminal may communicate through a sidelink unlicensed band (SL-U). When a terminal communicates through a sidelink unlicensed band, the sidelink communication must be performed taking into account various regulations required for the unlicensed band and the channel environment and characteristics of the unlicensed band. For example, the sidelink communication may operate taking into account various slot structures (e.g., slot, non-slot) for efficient operation in the SL-U. Furthermore, the sidelink communication may operate based on interlaced-RB-based transmission as a channel transmission scheme. Furthermore, new resource allocation methods, new channel access procedures (e.g., listen before talk (LBT)), dynamic physical sidelink feedback channel (PSFCH) resource structures, and other new physical channel structures may be applied to the sidelink communication taking into account the SL-U, but the application of such new resource allocation methods and new channel access procedures may not be limited to specific embodiments.

[0172] As an example, in consideration of the above, a transmission method for the second SCI, which is an SCI included in a PSSCH transmitted by a terminal for sidelink communication, can be newly set in consideration of SL-U. The following describes a second SCI transmission method taking into account the new SL-U system. Specifically, the following describes a transmission method taking into account the number of coded modulation symbols coded using a rate matching scheme for transmitting the second SCI.

[0173] As an example, in an SL system, a terminal can transmit a second SCI to another terminal through a PSSCH. Here, the number of symbols for the second SCI transmission can be determined. The number of symbols for the second SCI transmission may refer to the number of symbols modulated after channel coding. That is, the terminal can perform the second SCI transmission using a portion of the PSSCH resource region and can determine the number of symbols used for the second SCI transmission. As a specific example, the number of symbols used for the second SCI transmission can be determined by the following Equation 6.

[0174]

number

[0175] In Equation 6, O SCI2 is the number of 2nd stage SCI bits, and L SCI2 can be the number of CRC (cyclic redundancy check) bits for the 2nd SCI. SCI2 can be, but is not limited to, 24 bits. JPEG2026508064000040.jpg913 is associated with 1 st Stage SCI (1 st The offset value indicated in the second stage SCI may be a value for adjusting the code rate for the second SCI. JPEG2026508064000041.jpg922 may be the number of resource elements (RE) used for the 2nd SCI transmission in OFDM symbol l, where l may be as shown in Equation 7 below. JPEG2026508064000042.jpg914 can be expressed as Equation 8, where: JPEG2026508064000043.jpg914 is the number of PSSCH symbols for 2nd SCI rate matching, and the number of REs used for 2nd SCI transmission within OFDM symbol l based on the number of PSSCH symbols is JPEG2026508064000044.jpg922 can be determined, as will be described later. JPEG2026508064000045.jpg948, and can be determined taking into consideration the bandwidth of the PSSCH transmission expressed in units of the number of subcarriers. JPEG2026508064000046.jpg922 is the number of subcarriers on OFDM symbol l that carry the PSCCH and the PSCCH DMRS associated with the PSCCH transmission. This can be determined taking into account JPEG2026508064000047.jpg923, as will be described later.

[0176] Furthermore, γ may be the number of unmapped REs in a resource block to which the last coded symbol included in the second SCI is assigned. For example, γ may be a value added to ensure that resource allocation is performed in RB units. Furthermore, R may represent a coding rate indicated by an MCS (modulation and coding scheme) field in SCI format 1-A. Note that α may be a value set by an upper layer parameter "SL-scaling."

[0177]

number

[0178]

number

[0179] Furthermore, in Equation 8, JPEG2026508064000050.jpg911 is the number of OFDM symbols used for PSSCH transmission, JPEG2026508064000051.jpg913 is a value indicated through the PSFCH overhead indication field in SCI format 1-A, and means the number of OFDM symbols corresponding to the PSFCH overhead in one slot. Based on the above, a method for determining the number of coded code symbols for the 2nd SCI in the SL-U system will be described below.

[0180] For example, a procedure for determining a second SCI symbol may be performed. The procedure for determining the second SCI symbol may be configured to minimize an impact on a PSSCH rate matching (e.g., TBS determination) operation. Specifically, if the number of coded symbols for the second SCI transmission (e.g., coded symbols for second SCI resource mapping) is configured such that different TBS sizes are configured between an initial transmission and a retransmission associated with one TBS transmission, the UE may not obtain HARQ combining gain, which may result in performance degradation.

[0181] Considering the above, the number of coded symbols for the second SCI transmission can potentially be configured to minimize variability in radio resource usage due to other channels and reference signals. This allows the same TBS size to be determined between the initial transmission slot and the retransmission slot. As an example, consider a case where multiple PSSCH / PSCCH start OFDM symbols within one slot are configured by RRC signaling. Multiple PSSCH / PSCCH start OFDM symbols within one slot can be pre-configured, and two OFDM symbols per slot can be configured to be used as start OFDM symbols. However, this is merely an example and is not limiting.

[0182] The UE may be configured with a number of OFDM symbols (SL-length symbols) used for the sidelink as an upper layer parameter. Here, SL-length symbols may provide multiple values. Furthermore, the UE may be configured with a start symbol position (SL-start symbol) used for the sidelink as an upper layer parameter. SL-start symbol may also provide multiple values. However, this is merely an example and is not limiting.

[0183] Here, different numbers of symbols can be set depending on the start symbol position used for the sidelink. As a specific example, if the number of start OFDM symbols used for the sidelink is set to two, 'Sl-Startsymbol_1' may indicate the first start OFDM symbol position in one slot, and 'Sl-Startsymbol_2' may indicate the second start OFDM symbol position in one slot. The position and length of the OFDM symbols used for the sidelink in one slot are determined by a parameter for the number of OFDM symbols used for the sidelink (SL-lengthsymbols) and a parameter for the start symbol position used for the sidelink (SL-startsymbol), and these parameters may be configured in pairs through higher layer signaling.

[0184] Table 17 may be a list indicating a pair type of the number of OFDM symbols used for the sidelink (SL-lengthsymbols) parameter and the start symbol position (SL-startsymbol) parameter used for the sidelink. As a specific example, the pair type list may be in the form of "SL-lengthSymbols_1, SL-Startsymbol_1", "SL-lengthSymbols_2, SL-Startsymbol_2", etc., and corresponding index values ​​may be set. That is, the UE may receive the configuration of the number of OFDM symbols and the start symbol position value based on the pair index value of Table 17 through upper layer signaling, but is not limited thereto. As an example, the new upper layer parameters of Table 17 may be configuration values ​​for the SL-U system. Therefore, the UE can receive the configuration of the above-mentioned new upper layer parameters independently of the existing SL parameters.

[0185] [Table 17]

[0186] 20 is a diagram illustrating a method for setting multiple start symbols and symbol lengths for PSCCH and PSSCH transmission, which is applicable to the present disclosure. JPEG2026508064000053.jpg914 may be the number of PSSCH symbols for 2nd SCI rate matching, and the number of REs used for 2nd SCI transmission within OFDM symbol l based on the number of PSSCH symbols may be JPEG2026508064000054.jpg924 may be determined. Here, in Equation 8 for determining the number of PSSCH symbols for 2nd SCI rate matching, JPEG2026508064000055.jpg928 value needs to be determined.

[0187] As a specific example, JPEG2026508064000056.jpg911 may be determined based on the following Equation 9. The JPEG2026508064000057.jpg911 value may represent the number of OFDM symbols available for PSSCH transmission. Referring to Equation 9, JPEG2026508064000058.jpg911 value is the gap symbol from the "SL-lengthSymbols" value set by the upper layer. This can be any value except JPEG2026508064000059.jpg927.

[0188]

number

[0189] Here, as an example, The JPEG2026508064000061.jpg911 value can be determined taking into account channel occupancy based on LBT execution of unlicensed channels. Considering the above, the value of "SL-lengthSymbols" needs to be set to multiple values ​​by higher layer signaling (e.g., {SL-lengthSymbols_1, SL-lengthSymbols_2 ...}), unlike existing sidelink systems.

[0190] The SL-lengthSymbols value may be determined as one of a plurality of set values. As an example, the transmitting terminal may determine one of a plurality of values ​​as the SL-lengthSymbols value at the time when the LBT performed by the transmitting terminal is successful (i.e., when the channel is occupied). As a specific example, the transmitting terminal may determine one of a plurality of values ​​associated with 'SL-lengthSymbols' through the higher layer signaling after the LBT is successful. That is, one of the plurality of 'SL-lengthSymbols' values ​​may be determined and set in the terminal through the higher layer signaling. Through the reference value of the SL symbol The JPEG2026508064000062.jpg920 value can be determined.

[0191] 20, the transmitting terminal may occupy the channel by successfully completing the LBT in the middle of slot n. However, this is merely an example for ease of explanation and is not limited to this. After the LBT is successful, the transmitting terminal may prepare for transmission from the position of the next PSSCH / PSCCH transmission start OFDM symbol 2010. As an example, consider the case where two start OFDM symbol positions are set within a slot as described above, and an 'SL-lengthSymbols' value corresponding to each start position is set. After the LBT is successful, the transmitting terminal may determine the 'SL-lengthSymbols' value (A) based on the position of the second start OFDM symbol 2010, since the next start symbol 2010 is the second start OFDM symbol.

[0192] As another example, the 'SL-lengthSymbols' value may be determined based on SCI signaling, thereby increasing the flexibility of scheduling. As a specific example, the transmitting terminal may detect the PSCCH (SCI, 2020) through blind decoding at the first starting OFDM symbol position of slot n+1. However, this is merely an example for convenience of explanation and is not limited to this. Here, the 'SL-lengthSymbols' value may be determined through SCI signaling. As a specific example, the SCI may indicate non-slot-based PSSCH transmission such as 'B'. Alternatively, the SCI may indicate slot-based PSSCH transmission such as 'C'. In this case, the transmitting terminal may selectively perform scheduling. In consideration of the above, additional signaling regarding which scheduling or resource allocation to apply for the PSSCH may be required.

[0193] As a specific example, slot-based transmission may be transmission performed on a slot-by-slot basis, and non-slot-based transmission may be transmission based on the number of OFDM symbols. Scheduling (or resource allocation) for selective slot-based transmission or non-slot-based transmission, such as slot n+1, may be enabled / disabled and indicated by higher layer configuration. As another example, the enable / disable may be indicated through a field in the SCI without higher layer configuration, and is not limited to a specific embodiment. As another example, a case may be considered in which the UE obtains information about COT sharing from a COT-initiating UE. That is, the UE may receive channel occupancy time sharing from the COT-initiating UE. When the UE performs PSSCH / PSCCH transmission based on the COT sharing information, the UE may determine a starting OFDM symbol index and a symbol length based on the COT sharing information received based on at least one of the SCI and MAC CE signaling.

[0194] For example, the sidelink start OFDM symbol can be used for AGC purposes. That is, the transmitting terminal can repeatedly allocate information allocated to the next OFDM symbol following the start OFDM symbol for AGC purposes and perform transmission. The receiving terminal can perform AGC operation using the start OFDM symbol time. Then, the transmitting terminal can use the OFDM symbols following the AGC symbol for sidelink channels and signals other than the PSSCH / PSCCH. Here, the receiving terminal can determine an associated SL-lengthSymbols value based on the SL-startsymbol value at which to start receiving the PSCCH and the second SCI, and apply it to Equation 9 above. For example, the SL-startsymbol value may be determined based on the channel occupancy time according to the LBT result and from which start OFDM symbol in the slot sidelink transmission is started based on the channel occupancy time.

[0195] As another example, in the existing sidelink, AGC (1st OFDM symbol) and Tx-Rx switching (last symbol) always exist within one slot. However, in SL-U, the channel is occupied based on the channel occupation procedure, and transmission may be required at consecutive times (slot, non-slot) within the channel, which may require a different slot structure from the existing one. Considering the above, in SL-U, AGC and gap symbols may not exist in slots, and a method for indicating this may be required. As a specific example, the gap symbol in Equation 9 The JPEG2026508064000063.jpg927 value may be explicitly indicated based on SCI signaling and / or higher layer signaling. When the JPEG2026508064000064.jpg918 value is explicitly indicated by SCI signaling, the SCI may include a field indicating whether AGC / gap symbols are present and the number of symbols. The UE may determine second SCI matching and PSSCH TBS based on the above indication information. For example, configuration information regarding the number of AGC / gap symbols may be preset by higher layer signaling. The size of the field indicating whether AGC / gap symbols are present and the number of symbols in the SCI may be determined based on the preset number of AGC / gap symbols, and any of the above values ​​may be indicated via the SCI.

[0196] As another example, the gap symbol JPEG2026508064000065.jpg927 may be implicitly determined by PSSCH resource allocation information provided based on the sidelink start OFDM symbol position and the number of sidelink symbols according to the LBT success point. For example, if a specific gap symbol is used for PSSCH transmission based on the LBT success, the gap symbol in Equation 9 can be expressed as The JPEG2026508064000066.jpg927 value can be set differently.

[0197] As another example, The JPEG2026508064000067.jpg918 value is a value determined in advance as a representative value or reference value, and is different from the value used as the actual gap symbol. The reference value can be used. JPEG2026508064000068.jpg956 or gap symbol The JPEG2026508064000069.jpg927 value may be used as a preset value based on the SCI and / or higher layers. When the JPEG2026508064000070.jpg927 value is indicated by SCI signaling, the SCI may include a field indicating whether gap symbols are present and the number of gap symbols. The UE may determine second SCI rate matching and PSSCH TBS based on the indicated information. As another example, configuration information regarding the number of AGC / gap symbols may be preset by higher layer signaling. The size of the field indicating whether AGC / gap symbols are present and the number of symbols in the SCI may be determined based on the preset number of AGC / gap symbols, and any of the above values ​​may be indicated via the SCI.

[0198] FIG. 21 illustrates a rate matching method based on indication of the presence or absence of AGC / gap symbols applicable to the present disclosure.

[0199] Referring to FIG. 21, a transmitting terminal can perform sidelink transmission in consecutive sidelink slots after occupying a channel based on successful LBT for the same receiving terminal. The transmitting terminal can use gap symbols as resources for sidelink PSSCH / PSCCH transmission to maximize transmission efficiency. That is, unlike the existing sidelink, the transmitting terminal can perform sidelink transmission on gap symbols. As an example, referring to FIG. 21, OFDM symbol index 13 (2110) in slot n and OFDM symbol index 0 (2120) in slot n+1 can be used as resources for sidelink PSCCH / PSSCH transmission, thereby maximizing frequency utilization efficiency and improving data transmission rate. Here, the gap symbols The JPEG2026508064000071.jpg927 value may be determined based on a field in the SCI or higher layer signaling. The JPEG2026508064000072.jpg927 value may be explicitly indicated as one of the numbers {0, 1, 2} based on SCI signaling. The JPEG2026508064000073.jpg927 value may be implicitly determined by PSSCH resource allocation based on the LBT result. As an example, in FIG. 21, if specific gap symbols 2110 and 2120 are used for PSSCH transmission, The JPEG2026508064000074.jpg927 value can be implicitly determined to be different. Based on the above, the gap symbol in Equation 9 for the 2nd SCI rate matching The JPEG2026508064000075.jpg927 value can finally be determined.

[0200] As another example, FIG. 22 illustrates a method for transmitting sidelink data based on a successful LBT in the middle of a slot, which is applicable to the present disclosure. For example, a Uu link may not be established in the unlicensed band where SL-U is operated. Here, the sidelink symbol length, "sl-lengthSymbols", may be set to one of values ​​from 0 to 14*k-1. Furthermore, the unlicensed band sidelink symbol length, "Sl-unlicensed-lengthSymbols", may be set to one of values ​​from 0 to 11. As a specific example, sl-lengthSymbols may be set to 14, and Sl-unlicensed-lengthSymbols may be set to 7.

[0201] 22, for example, if the LBT is successful in the middle of slot n (2210), and then slot n (2210) as a partial slot and slot n+1 (2220) as a whole slot are concatenated to perform one PSSCH / PSCCH transmission, S1-lengthSymbols may be set to 21. However, this is merely a configuration for convenience of explanation and is not limited thereto.

[0202] The above description is based on the case where the slot does not include a PSFCH. However, the slot may include a PSFCH, and a rate matching method for allocating the second SCI to a slot including a PSFCH may be required. In Equation 8, the PSFCH overhead symbol is The JPEG2026508064000076.jpg913 value can be determined.

[0203] FIG. 23 is a diagram illustrating a SL non-slot-based PSFCH transmission method in SL-U that can be applied to the present disclosure. As an example, The JPEG2026508064000077.jpg913 value may be indicated on a non-slot basis. When the SL-PSFCH-period value is 1, 2, or 4, the PSFCH overhead indication field in SCI format 1-A can indicate whether or not PSFCH overhead is present. For example, when the SL-PSFCH-period value is 1 and PSFCH resources exist for each slot, the PSFCH overhead indication field in SCI format 1-A can indicate whether or not PSFCH overhead is present. On the other hand, when the SL-PSFCH-period value is 0, PSFCH overhead may not be present, and in this case 23, the terminal can successfully perform LBT in the middle of the slot and determine the starting OFDM symbol 2310 and the number of OFDM symbols available for PSSCH transmission. Here, based on Equation 8, the number of PSSCH symbols for the 2nd SCI rate matching is JPEG2026508064000079.jpg913 value may be reflected to determine the SCI. As an example, the SCI of the PSCCH 2320 detected by the terminal based on blind decoding may include a PSFCH overhead indication field. The JPEG2026508064000080.jpg913 value can be determined based on the PSFCH overhead indication field in the SCI, taking into account whether PSFCH overhead exists. As a specific example, if the PSFCH overhead indication field in the SCI indicates the existence of PSFCH overhead, JPEG2026508064000081.jpg922. However, this is merely an example and is not limited to this. On the other hand, if the PSFCH overhead indication field does not indicate the presence of PSFCH overhead, JPEG2026508064000082.jpg922. Also, as an example, if the SL-PSFCH-period value is additionally introduced and configured so that the PSFCH resource is configured for each non-slot, It may be set to, but is not limited to, JPEG2026508064000083.jpg922.

[0204] As another example, the PSFCH overhead indication may be performed dynamically. Here, the PSFCH overhead indication may be performed without PSFCH resource configuration such as SL-PSFCH-period. For example, the PSFCH overhead may be indicated through a PSFCH overhead indication field. Unlike the above, the PSFCH overhead may not depend on the SL-PSFCH-period value, which is a higher layer parameter, and may be indicated only through a PSFCH overhead indication field in the SCI. For example, in the existing sidelink, periodic PSFCH period configuration may be possible. On the other hand, in the SL-U, a case may be considered in which PSFCH resource configuration is possible only within the COT. Here, the UE may explicitly indicate the PSFCH overhead through SCI signaling on the occupied channel according to the channel occupation status based on the success of the LBT.

[0205] As another example, the PSFCH overhead may be indicated in an implicit manner. For example, if HARQ feedback for a PSSCH transmitted in a previous COT is not performed in the same COT, it may be determined that PSFCH transmission is to be performed in a specific slot in the next COT (e.g., the first slot in the next COT). Here, when a second SCI transmission is performed in the specific slot, On the other hand, if PSFCH transmission is not performed, It may be determined as JPEG2026508064000085.jpg922, but is not limited to this.

[0206] FIG. 24 illustrates a method for scheduling multiple TTIs through one SCI signaling, which is applicable to the present disclosure. For example, in an existing sidelink system, two OFDM symbols are allocated in every slot as gap symbols for AGC / Tx-Rx switching purposes. However, in an SL-U system, not all slots may include the gap symbols. For example, in an SL-U system, a UE can perform continuous sidelink transmissions through channels occupied within a channel occupancy time (COT) after a successful LBT. The transmission scheme described above allows a transmitting UE to perform sidelink transmissions in consecutive slots within the COT. For example, in FIG. 24, the UE can schedule all slots occupied within the COT after a successful LBT through one SCI 2410, thereby enabling data transmission even in the gap symbols. The receiving UE does not need to assume that all slots always include gap symbols. Therefore, gap symbols can be used for data transmission to improve resource efficiency and transmission performance in the SL-U system.

[0207] As a specific example, in the above-mentioned formula 6, The JPEG2026508064000086.jpg922 value, together with the α value, can be a value that determines the upper limit of the number of 2nd SCI encoded symbols. For example, JPEG2026508064000087.jpg922 may represent the number of REs for allocating the second SCI for each OFDM symbol. via JPEG2026508064000088.jpg1311 JPEG2026508064000089.jpg1342 operation can be performed. This allows the number of REs allocated to the 2nd SCI in the OFDM symbol to which the PSSCH is allocated to be calculated and scaled using the α value. As an example, for the 2nd SCI rate matching for the SL-U system, The determination of JPEG2026508064000090.jpg922 can be as follows: JPEG2026508064000091.jpg923 values ​​can be calculated. The JPEG2026508064000092.jpg923 value may represent the number of REs used for PSCCH in one OFDM symbol, and this value can be expressed in Equation 10. The JPEG2026508064000093.jpg922 value can be determined.

[0208]

number

[0209] Also, as an example, a case where multiplexing between SL-SSBs and PSSCH / PSCCH is applied can be considered. That is, a case where SL-SSBs are additionally allocated within PSSCH transmission resources can be considered. For example, in the existing sidelink, SL-SSBs may not be included in the resource pool. However, in SL-U, additional SL-SSB transmission can be considered in consideration of LBT failure, and some of the additional SL-SSBs can be transmitted within the resources where PSSCH / PSCCH are transmitted. Furthermore, it may be preferable for the above-mentioned SL-SSB transmission to be transmitted together with PSCCH / PSSCH to meet OCB / PSD requirements, but this is not limited to this.

[0210] FIG. 25 is a diagram illustrating a method of applying multiplexing between SL SSBs and PSSCH / PSCCH applicable to the present disclosure. As an example, when a terminal performs SL SSB transmission in an unlicensed band, the terminal can multiplex SL-SSB transmission with other sidelink physical layer transmissions such as PSSCH / PSCCH in the same slot to maximize the LBT success probability and improve transmission efficiency. Referring to FIG. 25, a portion of the PSSCH transmission resources can be used as SL-SSB 2510 transmission resources. Here, the second SCI rate matching can be performed taking into account whether or not the SL-SSB is present. As an example, as shown in FIG. 25, when the second SCI 2520 and the SL-SSB 2510 transmission are performed in the same slot, The JPEG2026508064000095.jpg922 value can be determined taking into account the SL-SSB transmission resource, as shown in Equation 10. On the other hand, if the 2nd SCI2520 and SL-SSB2510 transmissions are not performed in the same slot, then in Equation 10, JPEG2026508064000096.jpg925 value can be 0, based on this A JPEG2026508064000097.jpg922 value may be determined.

[0211] 26 is a diagram showing a case where an additional SL-SSB occasion applicable to the present disclosure is configured within a resource pool. Referring to FIG. 26, an additional SL-SSB 2610 transmission can be performed within a resource pool 2620. That is, an additional SL-SSB occasion can be configured within the resource pool. Here, 2nd SCI rate matching can be configured taking into account potential SL-SSB transmissions and is not limited to a specific embodiment.

[0212] As another example, a second SCI resource mapping operation for SL-U may be considered. For example, the UE may perform sidelink transmission in the COT based on the success of the LBT, and may perform sidelink transmission in consecutive slots. Here, for example, the success or failure of the LBT does not need to occur at a slot boundary. That is, the UE may succeed in the LBT in the middle of a slot. The UE may allocate the associated DMRS, PSCCH, and second SCI from a specific OFDM symbol (e.g., the AGC or PSCCH / PSSCH start symbol after the LBT is successful) based on the above-mentioned parameters.

[0213] FIG. 27 illustrates a method for performing non-slot-based sidelink transmission including a second SCI after a successful LBT, which is applicable to the present disclosure. FIG. 28 illustrates a method for performing non-slot-based and slot-based sidelink transmission including a second SCI after a successful LBT, which is applicable to the present disclosure. After a successful LBT, the UE may set a specific OFDM symbol as a starting OFDM symbol for PSSCH / PSCCH transmission within a slot. Referring to FIG. 27, starting OFDM symbol 2710 may be assigned based on AGC. The AGC symbol may be a symbol to which a signal for PSSCH / PSCCH or DMRS, PTRS, or CSI-RS assigned to the next symbol is duplicated and assigned, as described above. Then, the DMRS and PSSCH may be assigned to the next symbol. As an example, in FIG. 28, the UE may successfully perform an LBT in slot n. Therefore, the DMRS time-domain configuration within slot n (e.g., three DMRS symbols in a slot) may be maintained, and the number of available DMRS symbols within slot n, which is the first slot, may be determined based on the time point of the successful LBT. For example, in Figure 28, if AGC is configured as the starting PSSCH OFDM symbol 2810, the starting OFDM symbol may be configured through a higher layer, but is not limited to this. Also, in Figure 28, there may be no gap symbol between slot n and slot n+1 in the COT based on the LBT success of the terminal.

[0214] As an example, an operation considering a case of multiple consecutive slot transmissions associated with the second SCI rate matching may be performed. That is, the UE may successfully perform the LBT and perform sidelink transmission in multiple consecutive slots included in the COT interval based on the LBT. Here, the dynamic PSFCH resource indication associated with the second SCI rate matching may enable indication of one or more PSFCH resources per slot. Furthermore, the SCI may schedule multiple TTIs, as described above. Also, in the SL-U system, a case may be considered in which the SL-SSB is multiplexed and transmitted on the PSCCH / PSSCH resources, as described above. The success or failure of the LBT of the UE in the SL-U system may be determined on an RBS-by-RBS basis. Here, the existence or non-existence of the PSCCH may differ depending on the success or non-existence of the LBT for each configured RBS. Alternatively, if the LBT is successful in at least one RBS, it may be considered whether the PSCCH exists in only one RBS or in other RBSs.

[0215] Further, as an example, in Equation 6, the beta offset value can be higher than the initial transmission value during retransmission, and rate matching operation for the 2nd SCI allocation can be performed to reflect this.

[0216] As another example, the above-described operation may be considered when mapping the second SCI based on the first SCI PSFCH indication in association with the second SCI rate matching. Here, the channel state information (CSI)-reference signal (RS) may not be considered, and the DMRS for the TBS may be considered. Also, the UE may recognize the phase tracking reference signal (PT-RS) before decoding the second SCI. Furthermore, the second SCI may be allocated after the PSSCH DMRS symbol. For example, if the DMRS symbol is omitted, the second SCI allocation method may be different. As another example, when the UE performs blind retransmission, the TBS size may be maintained or set differently, and this is not limited to a specific embodiment.

[0217] Further, as an example, in Equation 6, the γ value for TBS calculation for the second SCI mapping may be set to 0, thereby allowing a fixed TBS size to be considered in HARQ operation. For example, γ is a value considered for generating the second SCI in RB units and may have a value between 0 and 11. Here, the γ value may be a value that is ignored as the actual TBS size increases, since the gap increases. For example, since the TBS value is determined based on quantization, the same TBS may be used in initial transmission and retransmission regardless of the γ value. However, this is not limited thereto. For example, the code rate of the second SCI may be smaller than the code rate of the first SCI, but may be different and is not limited to a specific embodiment.

[0218] FIG. 29 is a flowchart illustrating the operation of a wireless user equipment (UE) operating in a sidelink unlicensed band to which the present disclosure may be applied.

[0219] Referring to FIG. 29, a wireless user equipment (UE) may determine the number of OFDM symbols available for PSSCH transmission (S2910) and, based on the determined number, determine the number of coded symbols of the second SCI (S2920). The wireless user equipment may then determine the number of REs for the second SCI based on the number of coded symbols of the second SCI (S2930), map the second SCI to radio resources based on a starting OFDM symbol position-related parameter and a number-of-OFDM symbol-related parameter, and transmit the result to another wireless user equipment (S2940). Here, for example, the number of OFDM symbols available for PSSCH transmission may be determined as a value obtained by subtracting gap symbols from a sidelink length symbol (SL-length Symbols) value. For example, the sidelink length symbol value may be determined based on at least one of higher layer parameters and SCI signaling. Furthermore, the gap symbols may be determined based on at least one of higher layer parameters and SCI signaling.

[0220] Further, as an example, the gap symbols may be implicitly determined based on the starting OFDM symbol position and the number of OFDM symbols determined based on the LBT success time point of the wireless user equipment. Furthermore, the number of coded symbols of the second SCI may be determined by further reflecting the number of PSFCH symbols in the number of OFDM symbols available for PSSCH transmission. As another example, the number of PSFCH symbols may be determined as a specific value based on the PSFCH overhead indication field in the SCI. If the PSFCH overhead indication field in the SCI indicates the presence of a PSFCH, the number of PSFCH symbols may be determined as a first value, and if the PSFCH overhead indication field in the SCI indicates the absence of a PSFCH, the number of PSFCH symbols may be determined as 0. Furthermore, the number of resource elements of the second SCI may be determined based on the number of subcarriers associated with PSSCH transmission and the number of subcarriers on the OFDM symbols to which the PSCCH and the PSCCH DMRS associated with the PSSCH are allocated, as described above.

[0221] Furthermore, as an example, when SL-SSB is multiplexed with PSSCH / PSCCH based on a sidelink unlicensed band, the number of resource elements of the 2nd SCI may be further determined based on the number of SL-SSB resource elements.

[0222] FIG. 30 is a diagram showing a device configuration to which the present disclosure can be applied.

[0223] 30, a first device 3000 and a second device 3050 may communicate with each other. In this case, as an example, the first device 3000 may be a base station device, and the second device 3050 may be a terminal device. As another example, both the first device 3000 and the second device 3050 may be terminal devices. That is, the first device 3000 and the second device 3050 may be devices that communicate with each other based on NR-based communication.

[0224] As an example, consider a case where the first device 3000 is a base station device and the second device 3050 is a terminal device. In this case, the base station device 3000 may include a processor 3020, an antenna unit 3012, a transceiver 3014, and a memory 3016. The processor 3020 performs baseband-related signal processing and may include an upper layer processing unit 3030 and a physical layer processing unit 3040. The upper layer processing unit 3030 may process operations of a Medium Access Control (MAC) layer, a Radio Resource Control (RRC) layer, or higher layers. The physical layer processing unit 3040 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 3020 may also control the overall operation of the base station device 3000. The antenna unit 3012 may include one or more physical antennas. When multiple antennas are included, MIMO (Multiple Input Multiple Output) transmission and reception may be supported. The base station device 3000 may also support beamforming. The memory 3016 may store information processed by the processor 3020, software associated with the operation of the base station device 3000, an operating system, applications, etc., and may include components such as a buffer. The processor 3020 of the base station device 3000 may be configured to implement the operation of a base station in the embodiments described herein.

[0225] The terminal device 3050 may include a processor 3070, an antenna unit 3062, a transceiver 3064, and a memory 3066. As an example, in the present invention, the terminal device 3050 may communicate with the base station device 3000. As another example, in the present invention, the terminal device 3050 may perform sidelink communication with another terminal device. That is, the terminal device 3050 of the present invention refers to a device capable of communicating with at least one of the base station device 3000 and another terminal device, and is not limited to communication with a specific device. The processor 3070 performs baseband-related signal processing and may include an upper layer processing unit 3080 and a physical layer processing unit 3090. The upper layer processing unit 3080 may process operations of the MAC layer, the RRC layer, or higher layers. The physical layer processing unit 3090 may process operations of the PHY layer (e.g., downlink receive signal processing, uplink transmit signal processing, sidelink signal processing). In addition to performing baseband-related signal processing, the processor 3070 may control the overall operation of the terminal device 3050. The antenna unit 3062 may include one or more physical antennas, and when multiple antennas are included, MIMO transmission and reception may be supported. Beamforming may also be supported. The memory 3066 may store information processed by the processor 3070, software associated with the operation of the terminal device 3050, an operating system, applications, etc., and may include components such as a buffer. The terminal device 3050 according to an example of the present invention may be associated with a vehicle. For example, the terminal device 3050 may be incorporated into, located in, or located on the vehicle. The terminal device 3050 according to the present invention may also be the vehicle itself. The terminal device 3050 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 3050 to which the present invention can be applied 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 risk diagnosis, etc. It may also include any type of communication device that can perform a sidelink operation, such as an AR / VR device, or a sensor that performs a relay operation.

[0226] Here, the vehicle / terminal to which the present invention is applied may include an autonomous vehicle / terminal, a semi-autonomous vehicle / terminal, a non-autonomous vehicle / terminal, etc. Meanwhile, although the terminal device 3050 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. In addition, the terminal device 3050 according to an example of the present invention may also include various types of communication devices capable of cooperating to support an interactive service using a sidelink. That is, the terminal device 3050 may be used not only when directly supporting an interactive service using a sidelink, but also as a cooperating device for supporting an interactive service using a sidelink.

[0227] The terminal device 3050 may determine the number of OFDM symbols available for PSSCH transmission and, based on the number of coded symbols of the second SCI, determine the number of REs for the second SCI. The terminal device 3050 may also determine the number of REs for the second SCI based on the number of coded symbols of the second SCI, map the second SCI to radio resources based on a starting OFDM symbol position-related parameter and a number of OFDM symbols-related parameter, and transmit the result to another wireless user device. Here, for example, the number of OFDM symbols available for PSSCH transmission may be determined as a value obtained by subtracting gap symbols from a sidelink length symbol (SL-lengthSymbols) value. For example, the sidelink length symbol value may be determined based on at least one of higher layer parameters and SCI signaling. Furthermore, the gap symbols may be determined based on at least one of higher layer parameters and SCI signaling. Furthermore, for example, the gap symbols may be implicitly determined based on a starting OFDM symbol position and the number of OFDM symbols determined based on the LBT success time of the wireless user device. Furthermore, the number of coded symbols of the second SCI may be determined by further reflecting the number of PSFCH symbols in the number of OFDM symbols available for PSSCH transmission. As another example, the number of PSFCH symbols may be determined as a specific value based on the PSFCH overhead indication field in the SCI. If the PSFCH overhead indication field in the SCI indicates the presence of a PSFCH, the number of PSFCH symbols may be determined as a first value. If the PSFCH overhead indication field in the SCI indicates the absence of a PSFCH, the number of PSFCH symbols may be determined as 0. Furthermore, the number of resource elements of the second SCI may be determined based on the number of subcarriers associated with PSSCH transmission and the number of subcarriers on the OFDM symbols to which the PSCCH and the PSCCH DMRS associated with the PSSCH are allocated, as described above. As another example, if SL-SSB is multiplexed with PSSCH / PSCCH based on a sidelink unlicensed band, the number of resource elements of the second SCI may be further determined based on the number of SL-SSB resource elements.

[0228] 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.

[0229] 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.

[0230] 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]

[0231] The above may also be applied to other systems.

Claims

1. 1. A wireless user equipment (UE) operating in a sidelink unlicensed spectrum in a wireless communication system, comprising: at least one antenna for transmitting and receiving one or more radio signals; at least one processor; and a memory that stores instructions for the wireless user device when executed by the at least one processor; The operation of the wireless user equipment is to: determining a number of orthogonal frequency division multiplexing (OFDM) symbols available for physical sidelink shared channel (PSSCH) transmission; determining a number of coded symbols for a second sidelink control information (SCI) based on a number of OFDM symbols available for the PSSCH transmission; determining a number of resource elements (REs) for the second SCI based on the number of coded symbols of the second SCI; and The wireless user device includes a step of mapping the second SCI to a radio resource based on a parameter related to a starting OFDM symbol position and a parameter related to the number of OFDM symbols, and transmitting the second SCI to another wireless user device.

2. The number of OFDM symbols available for the PSSCH transmission is determined as a value obtained by subtracting gap symbols from a sidelink length symbol (SL-lengthSymbols) value, The wireless user equipment (UE) of claim 1 , wherein the sidelink length symbol value is determined based on at least one of a higher layer parameter and SCI signaling.

3. The wireless user equipment (UE) of claim 2 , wherein the gap symbols are determined based on at least one of the higher layer parameters and the SCI signaling.

4. The wireless user equipment (10) of claim 2, wherein the gap symbols are implicitly determined based on a starting OFDM symbol position and a number of OFDM symbols determined based on a time point at which the wireless user equipment (10) has successfully performed listen before talk (LBT).

5. 2. The wireless user equipment according to claim 1, wherein the number of coded symbols of the second SCI is determined by further reflecting the number of physical sidelink feedback channel (PSFCH) symbols in the number of OFDM symbols available for the PSSCH transmission.

6. The number of PSFCH symbols is determined as a specific value based on a PSFCH overhead indication field in an SCI; If the PSFCH overhead indication field in the SCI indicates the presence of a PSFCH, the number of PSFCH symbols is determined as a first value; The wireless user equipment (10) of claim 5, wherein if the PSFCH overhead indication field in the SCI indicates that a PSFCH is not present, the number of PSFCH symbols is determined as 0.

7. 2. The wireless user equipment according to claim 1, wherein the number of resource elements of the second SCI is determined based on the number of subcarriers associated with the PSSCH transmission and the number of subcarriers on an OFDM symbol to which a PSCCH (physical sidelink control channel) and a PSCCH DMRS (demodulation reference signal) associated with the PSSCH are allocated.

8. 8. The wireless user equipment according to claim 7, wherein, when a sidelink-synchronization signal block (SL-SSB) is multiplexed on a PSSCH / PSCCH based on the sidelink unlicensed band, the number of resource elements of the second SCI is determined further based on the number of SL-SSB resource elements.

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