Method and apparatus for performing sidelink communications over unlicensed spectrum

Abstract

A method for performing sidelink communication over an unlicensed spectrum, the method comprising determining total resource elements (RE) for a physical sidelink shared channel (PSSCH), and determining a transport block size (TBS) based on the total RE.

Description

[Technical Field]

[0001] This disclosure proposes a rate matching method for transmitting and receiving NR SL-U data channels over unlicensed spectrum. [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, 5G communication can support the transmission of physical signals or physical channels through multiple beams to overcome poor channel conditions such as high path loss, phase noise, and frequency offset that occur at high carrier frequencies. This enables 5G communication to support applications such as enhanced Mobile Broadband (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communication (URLLC).

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

[0006] The present invention relates to a rate matching method and apparatus for transmitting and receiving an NR SL-U data channel over an unlicensed spectrum, and to a method and apparatus for determining a transport block size (TBS) for a physical sidelink shared channel (PSSCH) in an NR SL-U system over an unlicensed spectrum. [Means for solving the problem]

[0007] A method for performing sidelink communication over an unlicensed spectrum, the method comprising: determining total resource elements (RE) for a physical sidelink shared channel (PSSCH); and determining a transport block size (TBS) based on the total RE. [Effects of the Invention]

[0008] The present disclosure can provide a rate matching method for transmitting and receiving NR SL-U data channels over unlicensed spectrum.

[0009] The present disclosure may provide a method for determining a transport block size (TBS) for a physical sidelink shared channel (PSSCH) in an NR SL-U system on an unlicensed spectrum. [Brief explanation of the drawings]

[0010] [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 may be a CPE and PSSCH RM operation for sidelink unlicensed spectrum applicable to the present disclosure. [Figure 21]FIG. 21 is a diagram showing PSSCH allocation and the presence or absence of AGC / Gap in various cases of SL-U scheduling and channel occupancy applicable to the present disclosure. [Figure 22] FIG. 22 is a diagram illustrating a PSSCH applicable to the present disclosure. [Figure 23] FIG. 23 is a diagram illustrating PSSCH DMRS overhead control in consideration of multi-TTI scheduling in SL-U, which is applicable to the present disclosure. [Figure 24] FIG. 24 is a diagram showing PSCCH duplication allocated to and transmitted by an RBS applicable to the present disclosure. [Figure 25] FIG. 25 is a diagram showing an SL-SSB applicable to the present disclosure. [Figure 26] FIG. 26 is a diagram showing an apparatus to which the present disclosure can be applied. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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).

[0022] 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.

[0023] First, a brief description will be given of the physical resource structure of the NR system to which the present invention is applied.

[0024] FIG. 1 is a diagram for explaining an NR frame structure to which the present disclosure can be applied.

[0025] 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 multiplication relationship between the base unit of NR time and the base unit of LTE time is κ = T s / T c =64.

[0026] 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.

[0027] 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:

[0028]

number

[0029] 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.

[0030] FIG. 2 is a diagram illustrating an NR resource structure to which the present disclosure may be applied.

[0031] 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.

[0032] 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.

[0033]

number

[0034] 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.

[0035] 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.

[0036] Table 1 below shows examples of pneumoradio supported by the NR system.

[0037] [Table 1]

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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).

[0044] [Table 2]

[0045] Table 2 shows the number of OFDM symbols per slot (N) for normal CP, depending on the subcarrier spacing setting (u). slot symb ), number of slots per frame (N frame,u slot ), the number of slots per subframe (N subframe,u slot) Table 2 shows the above values based on a normal slot having 14 OFDM symbols.

[0046] [Table 3]

[0047] 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.

[0048] 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.

[0049] [Table 4]

[0050] 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.

[0051] 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.

[0052] 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.

[0053] [Table 5-1] [Table 5-2]

[0054] 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.

[0055] 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.

[0056] Here, NR V2X capability is not necessarily limited to supporting only V2X services, and may optionally support the use of a certain V2X RAT.

[0057] 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).

[0058] 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.

[0059] 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.

[0060] FIG. 3 is a diagram illustrating an NR sidelink slot structure to which the present disclosure can be applied.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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).

[0065] 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.

[0066] 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.

[0067] [Table 6]

[0068] [Table 7-1] [Table 7-2] [Table 7-3]

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] [Table 8]

[0077] 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.

[0078] 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., the number of RBs does not equal 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) may refer to the remaining slots in a situation where a multiple of the length of the bitmap on the time resource (e.g., sl-TimeResource) is not established, and may not be used as an NR sidelink resource.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] [Table 9]

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] Referring to FIG. 9, to support wideband operation in shared spectrum access, the UE may receive an IntraCellGuardBandsPerSCS parameter for each uplink carrier (UL carrier) and downlink carrier (DL carrier) from the base station based on the base station configuration. The UE may receive N subcarrier spacing indexes (μ) on one carrier. RB-set,x A terminal may be provided with an intra-cell guard band of -1. Referring to FIG. 9, the terminal may be provided with higher layer signaling regarding the starting common resource block (CRB) for each guard band and the size of the number of CRBs. For example, a CRB may be a resource block defined / set based on point A, which is the starting point of the transmission bandwidth on a carrier in the frequency domain. The terminal 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. JPEG2025526098000016.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. JPEG2025526098000018.jpg972, N RB-set,x is the number of RB sets, and x may be set to DL or UL for downlink and uplink. RB-set,xThe RB 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 the RBS within one carrier.

[0094] 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.

[0095] Here, each RBS can be defined as a start CRB and an end CRB. The start CRB is JPEG2025526098000019.jpg1326 and the end CRB is JPEG2025526098000020.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 JPEG2025526098000021.jpg1322 will interfere with the wireless bandwidth.

[0096] 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 JPEG2025526098000022.jpg971. That is, the RBS index s is JPEG2025526098000023.jpg may be a resource block having a size of 1323, JPEG2025526098000024.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.

[0097]

number

[0098]

number

[0099]

number

[0100] 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 JPEG2025526098000028.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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] [Table 10]

[0107] 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.

[0108] [Table 11]

[0109] 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.

[0110] 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.

[0111] 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.

[0112] [Table 12]

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] [Table 13]

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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. As 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.

[0122] [Table 14]

[0123] 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.

[0124] [Table 15]

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] [Table 16]

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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).

[0145] 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.

[0146] 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.

[0147] FIG. 19 illustrates a sidelink unlicensed band resource pool configuration method applicable to the present disclosure.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] Furthermore, as an example, frequency resource reservation can also be indicated through the PSCCH (physical sidelink control channel). At this time, the frequency resource reservation indication can be executed in the second slot or the second / third slots based on the PSCCH received within the lowest interleaving index among the interleaving indexes defined within one carrier bandwidth. The interleaving structure can be set to 10 interleavings (i.e., M = 10) with a 15 kHz SCS and 5 interleavings (i.e., M = 5) with a 30 kHz SCS based on the LBT BW considered in the unlicensed band, as described above. Specifically, considering that the number of RBs for constituting one RBS is 100 to 110 RBs with a 15 kHz SCS and 50 to 55 RBs with a 30 kHz SCS based on the LBT BW, the interleaving structure can be set as described above.

[0158] That is, in the case of a 15 kHz SCS, there may exist a partial resource (i.e., RB) of the same interleaving every 10 RBs. However, the interleaving value can also be configured with other values based on at least any one of other RBS sizes (LBT BW), SCS, and the number of RBs constituting one interleaving, and is not limited to a specific embodiment.

[0159] <Proposal for TBS Size Determination Method for PSSCH in NR SL-U System> For the PSSCH assigned by SCI in an existing wireless communication system (e.g., R16 NR SL system), the terminal operation regarding which TBS size value should be determined within the indicated TBS table is defined considering the set TBS tables (normal table, URLLC purpose table).

[0160] On the other hand, unlike existing SL systems, the NR SL-U system has many newly designed standard technologies that take into account various regulations required on unlicensed channels and the channel environment and characteristics of unlicensed bands. It is expected that new physical channel structures, such as various slot structures, channel transmission schemes, new resource allocation methods, LBT application, minislot structures, and dynamic PSFCH resource structures, required for operating NR SL on unlicensed bands will be considered. Therefore, a new method for rate matching must be introduced for PSSCH transmission. This invention proposes a method for determining the TBS size for PSSCH transmission taking into account the new NR SL-U system.

[0161] The terminal must first determine the number of REs allocated for PSSCH transmission in one slot. Here, the terminal must first determine the number of REs allocated for PSSCH transmission in one slot (N' RE ) must be determined, which can be expressed as Equation 6 below.

[0162]

number

[0163] As an example, in Equation 6 JPEG2025526098000037.jpg89 is 12, JPEG2025526098000038.jpg89 can be sl-LengthSymbols-2:sl-LengthSymbols upper layer parameters. JPEG2025526098000039.jpg89 can be 3 if the "PSFCH overhead indication" field in SCI format 1-A indicates "1", otherwise it can be 0 (if sl-PSFCH-Period has the value 2 or 4). If the value of sl-PSFCH-Period is 0, TIFF2025526098000040.tif17126 If the value of sl-PSFCH-Period is 1, then TIFF2025526098000041.tif15126 is.

[0164] Furthermore, as an example, JPEG2025526098000042.jpg89 may be the overhead given by the upper layer parameter "sl-X-Overhead". JPEG2025526098000043.jpg89 may be as shown in Table 17 below, determined by the upper layer parameter "sl-PSSCH-DMRS-TimePattern".

[0165] [Table 17]

[0166] The UE may determine the total number of REs allocated for the PSSCH, which may be expressed as Equation 7 below.

[0167]

number

[0168] where: JPEG2025526098000046.jpg89 is the total number of PRBs allocated for PSSCH, JPEG2025526098000047.jpg89 is the total number of REs occupied by PSCCH and PSCCH DMRS, JPEG2025526098000048.jpg89 is the number of coded modulation symbols generated for secondary SCI transmission with the assumption that γ = 0. In the case of two-layer transmission, it may be, but is not limited to, the number of corresponding symbols before duplication.

[0169] Based on the determined total number of REs for the PSSCH, the terminal determines the TBS by performing steps 2), 3), and 4) in Table 18 below.

[0170] [Table 18-1] [Table 18-2]

[0171] Basically, when determining the TBS, the difference between the target coding rate indicated by the MCS and the actual coding rate (the ratio of the TBS to the actual amount of used resources) must be minimized. Furthermore, whether the overhead that may occur in each slot among multiple slots in which one TB is transmitted is deterministic or non-deterministic is also considered to be an important factor to consider in determining the TBS in the present invention. From this perspective, it is necessary to design a new TBS determination method that takes into account new operations and technologies that can be considered by NR SL-U. A specific handling method for this is proposed as follows.

[0172] In the signaling proposed below, SCI signaling can refer to the primary SCI or secondary SCI, and higher layer signaling refers to signaling from layers above the PHY layer, including the MAC and RRC layers, and pre-configured signals can also be collectively referred to as higher layer configurations.

[0173] Discussion on PSSCH TBS determination Basically, RAN1 does not consider the case where a terminal has different TBS sizes between initial transmission and retransmission (as agreed upon in previous RAN1#100).

[0174] In the case of Uu, the gNB can always recognize the PDCCH reception status of the terminal. Therefore, the gNB can ensure that the TBS size is maintained the same between initial transmission and retransmission. That is, the base station can adjust the TBS calculation equation or reuse the previous TBS so that the terminal always determines the same TBS.

[0175] On the other hand, in SL, the Tx UE sometimes does not know information about the PSCCH decoding status of the receiving terminal. For example, in cases such as blind HARQ retransmission and NACK-only feedback, it is difficult for the Tx UE to accurately grasp the PSCCH reception status. Therefore, in this case, in the current standard, the terminal only determines the TBS through the TBS calculation equation.

[0176] In existing SL, the MCS, the presence or absence of PSFCH, and SL RSs (DMRS, PT-RS) may be changed between initial transmission and retransmission. Therefore, the number of reference REs must be determined to determine the TBS. For example, the PSFCH overhead indicator, averaged DMRS over configured patterns, and a configured overhead per resource pool are all taken into consideration to ensure that the same TBS is determined. However, some flexibility in Tx parameters must be ensured.

[0177] The gamma value is usually a value that considers the secondary SCI to have PRB-level mapping granularity, meaning that the actual secondary SCI may not be an integer multiple of the PRB unit.

[0178] In some cases, the Tx UE may have difficulty adjusting the 2nd SCI RE mapping according to the resource pool level configuration (eg, the PSFCH period which affects the time domain DMRS pattern and the corresponding 2nd SCI RE mapping).

[0179] The DMRS pattern in the initial transmission and the DMRS pattern in the retransmission may be different considering different channel conditions and speeds. In addition, the PT-RS may also be changed since it is determined based on the DMRS pattern. This may cause different gamma values, which may result in different TBS sizes.

[0180] -> When determining the PSSCH TBS, the gamma value is assumed to be 0.

[0181] Design Issue 1: PSSCH TBS determination operation considering the presence or absence of various Gap / AGC symbols to determine the number of PSSCH transmission symbols In conventional NR SL systems, Gap symbols for AGC and Tx-Rx switching are always excluded from PSSCH transmission symbols because they exist in all PSSCH slots (non-PSFCH slots).

[0182] On the other hand, as shown in the figure above, in an NR SL-U system, after a successful LBT, transmission must be maintained for a period longer than a small gap (e.g., a 16 us or 25 us gap) to prevent other transmitting nodes from seizing the unlicensed channel during the COT time interval. The AGC / Gap symbols in the existing SL slot structure are located in the first and last OFDM symbols, respectively (when there is no PSFCH). Furthermore, in slots with additional PSFCH resources, additional overhead is incurred due to PSFCH transmission. The figure above generally illustrates the case where transmissions including at least SL RSs related to the PSCCH / 2nd SCI / PSSCH are performed per slot. In such cases, since there is no SL transmission during the time corresponding to the AGC (@OFDM Symbol #0) / Gap (@OFDM Symbol #13) symbols, there is a risk that the occupied resources of the unlicensed channel may be seized by other transmitting nodes. To prevent this, NR SL-U can apply CPE (CP Extension), as in existing NR-U. That is, the CP length of the previous OFDM symbol can be further extended to fill the empty time space in the AGC or Gap symbol with SL transmission. The left side of the above figure shows an example of such an operation. For example, to maintain the resources occupied by the last Gap symbol (OFDM symbol #13, based on a normal slot with a normal CP), the CP of the first OFDM symbol (OFDM#0, green symbol) of the previous slot can be extended and transmitted over part or the entire time of the corresponding Gap symbol in advance.

[0183] Instead of this method, a PSSCH RM method may be used as a method for performing SL transmission on the corresponding AGC or Gap symbol. That is, this method utilizes the resources on the corresponding symbol as resources for PSSCH transmission in order to utilize them more efficiently. This method basically assumes the transmission of sidelink channels / signals such as continuous PSSCH / PSCCH / 2nd SCI. That is, after the transmitting terminal has successfully completed LBT, it maintains the transmission of sidelink channels / signals on continuous slots for the COT time, thereby avoiding unnecessary LBT procedures. This has the advantage of improving channel utilization efficiency for the entire unlicensed band and providing a positive impact on other RAT systems. Of course, a disadvantage is that PSSCH RM operation may be somewhat complicated, but this method is quite plausible considering the performance improvements obtained through additional standard changes.

[0184] That is, unlike the existing SL, the presence or absence of AGC / Gap symbols is not stable in SL-U. Therefore, the TBS size can be determined through various methods, such as a method that can indicate the presence or absence of such overhead or an assumption about the presence of specific overhead.

[0185] As described above, the method of processing or utilizing the AGC / Gap symbols requires structural changes to the existing PSSCH TBS determination method, and the present invention proposes a specific method for doing so as follows.

[0186] FIG. 20 may be a CPE and PSSCH RM operation for sidelink unlicensed spectrum applicable to the present disclosure.

[0187] How to handle AGC / Gap symbol overhead: The terminal allocates the number of REs (N') allocated for PSSCH transmission within one PRB. REIf interlace-based resource allocation is configured or determined for PSSCH transmission, the number of REs allocated for PSSCH transmission may be determined based on one PRB in an interlace, as shown in Equation 8 below.

[0188]

number

[0189] With respect to the method defined on the existing SL system, a new handling method for the new SL-U system is proposed as follows.

[0190] ○Method 1 . On the other hand, if AGC / Gap symbols are used for PSSCH transmission through PSSCH Rate Matching (RM) without applying CPE, whether or not to use the AGC / Gap symbols can be indicated / determined dynamically by SCI signaling (primary SCI or secondary SCI) or semi-statically by upper layer configuration, unlike existing methods. The signaling is actually a value for the receiving terminal rather than the transmitting terminal, and from the transmitting terminal's perspective, it is assumed to be a value determined by itself and already known. That is, the AGC / Gap symbols that are always excluded from PSSCH transmission symbols in existing PSSCH RM operations can be used as additional PSSCH transmission symbols dynamically by SCI signaling (primary SCI or secondary SCI) or depending on whether or not an upper layer configuration is available, so this can be applied to the PSSCH TBS determination method.

[0191] Alt1 JPEG2025526098000052.jpg1091

[0192] Alt2 JPEG2025526098000053.jpg10100

[0193] where: JPEG2025526098000054.jpg818 is a value reflecting whether or not AGC and / or Gap symbols are present according to the proposed signaling. If it is determined by an upper layer parameter of the terminal or a terminal scheduler, it is possible to determine whether or not AGC / Gap is present in one slot according to the determined value and calculate the number of PSSCH transmission symbols. For example, The JPEG2025526098000055.jpg818 value can be selected and indicated by one of {0, 1, 2}. Of course, values greater than 2 may also be included when additional settings (e.g., whether or not to transmit PSFCH) are considered within one slot. The JPEG2025526098000056.jpg818 value can also be applied.

[0194] Furthermore, as in Alt2), the value of the number of symbols for the presence or absence of AGC and Gap symbols JPEG2025526098000057.jpg842 can be indicated separately and can be determined independently to determine the number of symbols for the sidelink transmission. For example, depending on the scheduling of the transmitting terminal, there may be all AGC and / or Gap (Tx-Rx switching) symbols, only one symbol, or no symbols per slot. Therefore, depending on such a scheduling scheme, SCI signaling for the information may be required.

[0195] As another example, when SL transmission resources are indicated based on a configured grant, information related to the AGC / Gap can be provided based on higher layer parameters.

[0196] In the case of SCI signaling, a new field corresponding to 1 or 2 bits can be configured and defined in the primary SCI or secondary SCI format.

[0197] sl-LengthSymbols: This is the number of OFDM symbols used for SL transmission within one slot as a higher layer parameter.

[0198] ○Method 2 The transmitting terminal shall newly define a new sl_unlicensed-LengthSymbols value that reflects the use of AGC / Gap symbols and / or considerations regarding non-slot-based PSSCH transmission for determining the PSSCH TBS. JPEG2025526098000058.jpg818 value can be determined. That is, the sl-LengthSymbols parameter, which is an upper layer parameter, can be replaced with the new sl_unlicensed-LengthSymbols.

[0199] Alt3 JPEG2025526098000059.jpg979

[0200] ○Method 3 With a view to having a certain amount of overhead between the initial transmission and subsequent retransmissions for one TB transmission, JPEG2025526098000060.jpg849 Parameters for can be defined and applied to the PSSCH RM operation. JPEG2025526098000061.jpg846 is a method of determining the reference number by slot or SCI signaling or upper layer configuration based on an overall average value or the largest / smallest value, rather than the number of actual AGC or Gap symbols used, and performing PSSCH RM. As described above, the number of reference symbols that can be provided by the SCI signaling described herein is signaling for the receiving terminal, and the transmitting terminal determines the value related to the number of symbols by itself, so naturally, it is not required to receive the signaling.

[0201] JPEG2025526098000062.jpg852 ○For each COT In this case, it can be considered as a reference value determined based on the average AGC / Gap symbol overhead of slots present in one COT. That is, the PSSCH transmission symbol for one TB transmission can be determined taking into account the overhead (number of symbols) of the reference AGC / Gap symbol in the COT. And / or ○ Per resource pool, per carrier / BWP and / or per RBS In this case, it can be considered as a reference value determined based on the average AGC / Gap symbol overhead of slots present in one resource pool, Carrier / BWP and / or RBS.

[0202] The transmitting terminal determines the number of independent reference symbols to determine the PSSCH TBS size, which can be set by upper layer parameters. Of course, from the perspective of the receiving terminal, the transmitting terminal also performs decoding by executing PSSCH RM based on the value indicated by SCI signaling or set by upper layers.

[0203] FIG. 21 is a diagram showing PSSCH allocation and the presence or absence of AGC / Gap in various cases of SL-U scheduling and channel occupancy applicable to the present disclosure.

[0204] Case1) Tx UE->Rx UE#1 and Tx UE->Rx UE#2 Sidelink transmission (PSSCH / PSCCH / 2nd SCI) for Tx UE -> Rx UE #1. After the LBT procedure performed by the transmitting terminal is successful, the transmitting terminal performs sidelink transmission to receiving terminal #1 over two consecutive slots. The transmitting terminal also performs sidelink transmission to receiving terminal #2 over two consecutive slots. There may not be a gap symbol between two consecutive slots transmitted to each receiving terminal. In this case, the gap symbol portion can be taken into account by the proposed method when determining the TBS size for PSSCH transmission.

[0205] Case2)Tx UE->Rx UE#1 with single TTI scheduling As in Case 1, after a successful LBT, the transmitting terminal can transmit four PSSCHs over four consecutive slots for one Rx UE #1. In this case, the presence or absence of AGC and / or Gap symbols in each slot can be determined as shown in the figure, so the proposed method for determining the TBS size taking such characteristics into account can be applied.

[0206] Case3)Tx UE->Rx UE#1 with multi TTI scheduling Unlike Case 2 above, the transmitting terminal can transmit multiple TBs to the receiving terminal through a single SCI signal. In this case, as shown in the figure, AGC is performed only in the first slot for PSSCH transmission after a successful LBT, but there may be a Gap symbol for Tx-Rx switching in the last PSSCH transmission slot. Reflecting this, the PSSCH TBS size can be determined using the proposed method.

[0207] PSSCH Symbol Decision Method Considering LBT Results In addition to the PSSCH symbol determination method that takes into account the presence or absence of the dynamic AGC / GAP symbol, non-slot-based PSSCH / PSCCH can be considered instead of slot-based PSSCH / PSCCH transmission. As shown in the figure below, the success or failure of LBT performed to occupy a channel in an unlicensed band does not always occur at a slot boundary, but can occur at some point in between. Therefore, PSSCH / PSCCH transmission can be performed from any OFDM symbol index in the middle of a slot so that the channel can be occupied immediately after the LBT is successful.

[0208] Since this transmission method is completely different from the existing PSCCH / PSSCH allocation in terms of determining the TBS size, the TBS size must be determined taking these characteristics into consideration.

[0209] FIG. 22 is a diagram illustrating a PSSCH applicable to the present disclosure.

[0210] In addition to the PSSCH symbol determination method that takes into account the presence or absence of the dynamic AGC / GAP symbol, if information about the COT duration is taken into account including PSSCH transmission, an additional PSSCH symbol determination method can be applied. The following equation is one of the equations proposed in Issue 1. Other equations may be applied depending on Issue 1. It is mentioned here as just one example. If the start of PSSCH transmission taking into account the LBT result below can consider additional positions rather than always fixing only the slot boundary, the method proposed below can also be further considered. Here, we propose a method that uses the sl-LengthSymbols value differently. JPEG2025526098000063.jpg981

[0211] Method 1) Use the number of PSSCH transmission symbols for a non-slot-based PSSCH such as PSSCH #0 provided by SCI signaling. The sl-LengthSymbols value can be determined by SCI signaling.

[0212] Method 2) By SCI signaling, the average value of the PSSCH symbols for slot n and slot n+1, i.e., non-slot and slot-based transmission, is used as the PSSCH transmission symbol. This value can also be set by the transmitting terminal to the receiving terminal via SCI signaling or by higher layer parameters for each resource pool.

[0213] Method 3) The largest value among slot n and slot n+1, i.e., PSSCH symbols for non-slot and slot-based transmission, is used as the PSSCH transmission symbol by SCI signaling. This value can also be set by the transmitting terminal to the receiving terminal via SCI signaling or by higher layer parameters for each resource pool.

[0214] Design Issue 2. PSSCH DMRS Overhead In order to minimize the LBT procedure performed by the transmitting terminal, a method of scheduling and transmitting large data size transmissions in consecutive slots at once during the time when the channel is occupied upon one successful LBT may be considered. In the existing SL system, data transmission scheduling was possible in multiple slots for only one TB transmission through one SCI signaling, but as shown in the above figure, it is possible to consider scheduling for multiple TB transmissions in multiple consecutive slots through one SCI signaling in consideration of the possibility of opportunistic resource utilization in unlicensed bands.

[0215] That is, in the SL-U system, a transmitting terminal can schedule one or more TB transmissions in multiple consecutive slots to the same receiving terminal(s) through one SCI signaling. Such a resource allocation method can minimize the LBT execution by the transmitting terminal and open up opportunities for additional spectral efficiency improvements.

[0216] FIG. 23 is a diagram illustrating PSSCH DMRS overhead control in consideration of multi-TTI scheduling in SL-U, which is applicable to the present disclosure.

[0217] When such a resource allocation method is configured and used to instruct scheduling, the transmitting terminal can potentially eliminate the existing overhead transmitted for each slot. From the perspective of PSSCH DMRS, when data TB transmission is performed across multiple slots to the same receiving terminal(s), the DMRS overhead can be reduced in some slots. In particular, when considering a scenario using an unlicensed band, the mobility of terminals performing sidelink transmission and reception over an unlicensed band is limited.

[0218] The terminal allocates the number of REs (N') allocated for PSSCH transmission within one PRB. RE ) may need to be determined, which may be as follows:

[0219]

number

[0220] As an example, in Equation 9 JPEG2025526098000065.jpg89 is 12, JPEG2025526098000066.jpg89 can be sl-LengthSymbols-2:sl-LengthSymbols upper layer parameters. JPEG2025526098000067.jpg89 can be 3 if the "PSFCH overhead indication" field in SCI format 1-A indicates "1", otherwise it can be 0 (if the value of sl-PSFCH-Period is 2 or 4). If the value of sl-PSFCH-Period is 0, TIFF2025526098000068.tif16126 If the value of sl-PSFCH-Period is 1, then TIFF2025526098000069.tif15126 is.

[0221] Furthermore, as an example, JPEG2025526098000070.jpg89 may be the overhead given by the upper layer parameter "sl-X-Overhead". JPEG2025526098000071.jpg89 may be as shown in Table 19 below, determined by the upper layer parameter "sl-PSSCH-DMRS-TimePattern".

[0222] [Table 19]

[0223] The existing PSSCH DMRS REs are considered as overhead within one PRB, and are therefore excluded from the number of REs for PSSCH transmission resources. In fact, the existing SL system also allows PSSCH scheduling per slot, and can indicate different DMRS mapping patterns for each slot by each SCI signaling. However, by indicating different DMRS mapping patterns depending on the UE's mobility, channel environment, and scheduling accordingly, stable resource utilization is possible when determining TBS.

[0224] Method 1 An additional DMRS pattern is configured in the upper layer parameter sl-PSSCH-DMRS-TimePattern that configures the DMRS table. At least no DMRS pattern TIFF2025526098000073.tif17126 can be added to the parameters and configured in the table above.

[0225] Method 2 With the DMRS pattern actually used based on the SCI field value indicating the PSSCH DMRS pattern TIFF2025526098000074.tif17126 That is, a different PSSCH DMRS actual DMRS overhead value is applied for TBS determination for each slot.

[0226] Method 3 The reference DMRS pattern was considered based on the DMRS pattern dictated by primary SCI signaling. JPEG2025526098000075.jpg89 is determined. That is, a reference DMRS pattern for TBS determination, rather than a DMRS pattern for actual PSSCH decoding, can be indicated through SCI signaling. Therefore, the actual PSSCH DMRS mapping pattern and the DMRS mapping pattern considered for TBS determination may be different, and the DMRS allocation pattern considered for TBS determination is defined as a reference DMRS allocation pattern and used to determine the TBS size.

[0227] Design Issue 3. PSCCH / PSCCH DMRS Overhead The UE divides the total number of REs allocated for PSSCH into the number of REs per RB, N', as follows: RE The final determination is made taking into account the number of scheduled RBs and the associated SCI overhead, and can be expressed as Equation 10 below.

[0228]

number

[0229] As an example, JPEG2025526098000077.jpg710 is the total number of PRBs allocated for PSSCH, JPEG2025526098000078.jpg813 is the total number of REs occupied by PSCCH and PSCCH DMRS, TIFF2025526098000079.tif16126 With the above assumptions, it is the number of coded modulation symbols generated for the second SCI transmission. In the case of two-layer transmission, it is the number of corresponding symbols before duplication.

[0230] Here, the total number of REs occupied by the PSCCH and PSCCH DMRS differs from the conventional method, and the PSCCH may not exist in all SL slots. That is, depending on the scheduling method set, it is difficult to always assume the same PSCCH overhead for PSSCH transmissions on multiple slots scheduling the same TB in SL-U. Referring to FIGS. 18 and 19 as an example, when multi-TTI scheduling is used, PSCCH transmission associated with one TB transmission may be performed in only some or one of all PSSCH transmission slots. That is, PSCCH transmission scheduling multiple PSSCHs transmitted across multiple slots associated with one TB transmission may be performed in only some or one of the multiple slots. In such a case, an enhancement technique related to the formula needs to be applied to determine the PSSCH TBS.

[0231] LBT success or failure (success or failure per RBS) - The existence of PSCCH may differ depending on the success or failure of LBT for each configured RBS. Alternatively, if LBT is successful for at least one RBS, it may exist only in one RBS, or it may exist in other RBSs as well.

[0232] If multi-TTI scheduling is configured or indicated, ○Method 1 PSCCH / PSCCH DMRS overhead JPEG2025526098000080.jpg813 is determined using a value calculated as the average over its scheduled PSSCH transmission slot. ○Method 2 PSCCH / PSCCH DMRS overhead JPEG2025526098000081.jpg813 uses PSCCH / PSCCH DMRS overhead values determined by higher layer parameters.

[0233] If LBT is successful on one or more additional consecutive RBSs (as shown in the figure below), the additional PSCCH overhead is calculated taking into account whether PSCCH duplication is applicable.

[0234] In addition to the above method, PSCCH / PSCCH DMRS overhead in the frequency domain JPEG2025526098000082.jpg813 is multiplied by the number of PSCCH duplications, so the PSCCH / PSCCH DMRS overhead is Calculate JPEG2025526098000083.jpg813.

[0235] FIG. 24 is a diagram showing PSCCH duplication allocated to and transmitted by an RBS applicable to the present disclosure.

[0236] Design Issue 4. Possibility of PSFCH overhead The terminal allocates the number of REs (N') allocated for PSSCH transmission within one PRB. RE ) must be determined, which can be expressed as Equation 11 below.

[0237]

number

[0238] As an example, JPEG2025526098000085.jpg89 can be 3 if the "PSFCH overhead indication" field in SCI format 1-A indicates "1". Otherwise, it can be 0 (if the sl-PSFCH-Period value is 2 or 4). If the value of sl-PSFCH-Period is 0, TIFF2025526098000086.tif18126 If the value of sl-PSFCH-Period is 1, then TIFF2025526098000087.tif16126 is.

[0239] As another example, JPEG2025526098000088.jpg89 could be 3.

[0240] Unlike the existing SL PSFCH transmission periodicity setting, in SL-U, PSFCH transmission / reception can be performed based on an SCI trigger if LBT is successful. That is, instead of considering PSFCH overhead through an SCI indication on PSFCH resources periodically set by a higher layer, PSFCH transmission on a specific SL slot can be considered together with an SCI trigger without PSFCH resource setting by the higher layer or based on the ability to set PSFCH transmission resources in specific slots within a COT.

[0241] In this case, unlike the existing method of accurately determining PSFCH overhead through higher layer parameters and SCI signaling, various types of PSFCH transmission methods may be considered depending on the results of LBT and the proposed PSFCH resource configuration and SCI indication methods.

[0242] When more than one PSFCH transmission per slot is performed in SL-U, the increased number of PSFCH transmission symbols must be removed from the number of REs allocated for PSSCH transmission.

[0243] Design Issue 5.SL SSB Existence Existing SL does not consider SL-SSB transmission within a resource pool. In contrast, in SL-U, if LBT is successful, SL-SSB transmission is generally possible, so SL-SSB transmission must be considered along with PSSCH transmission. Furthermore, to meet the OCB requirement, SL-SSBs transmitted over 11 RBs must be multiplexed with PSSCH rather than transmitted alone. For example, after LBT is successful, SL-SSBs and PSSCHs can be multiplexed in the same slot using FDM or TDM. In this case, the overhead for SL-SSBs must be considered when determining the number of resources for PSSCH transmission.

[0244] FIG. 25 is a diagram showing an SL-SSB applicable to the present disclosure.

[0245] Method 1 The total number of REs allocated for PSSCH is determined to reflect the actual SL-SSB overhead as follows:

[0246] The terminal divides the total number of REs allocated for the PSSCH by the number of REs per RB, N', as follows: RE The TBS size for the PSSCH is finally determined taking into consideration the number of scheduled RBs and the associated SL SSB overhead. As shown in the above figure, the TBS size for the PSSCH can be determined by excluding resources for S-SSBs from the REs allocated to the PSSCH, and can be expressed as follows:

[0247]

number

[0248] The TBS value is calculated by excluding REs corresponding to SL-SSB from the total number of PSSCH REs.

[0249] Method 2 The terminal allocates the number of REs (N') allocated for PSSCH transmission within one PRB. RE ) must be determined.

[0250] Alt1 JPEG2025526098000090.jpg11126

[0251] Alt2 JPEG2025526098000091.jpg8128

[0252] As an example, when S-SSBs are multiplexed with PSSCH resources as shown in FIG. 25, the TBS size can be determined taking into account the S-SSB overhead.

[0253] FIG. 26 is a diagram illustrating a base station apparatus and a terminal apparatus to which the present disclosure can be applied.

[0254] The base station device 3200 may include a processor 3220 , an antenna unit 3212 , a transceiver 3214 , and a memory 3216 .

[0255] The processor 3220 performs baseband-related signal processing and may include an upper layer processing unit 3230 and a physical layer processing unit 3240. The upper layer processing unit 3230 may process operations of a Medium Access Control (MAC) layer, a Radio Resource Control (RRC) layer, or higher layers. The physical layer processing unit 3240 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 3220 may control the overall operation of the base station device 3200.

[0256] The antenna unit 3212 may include one or more physical antennas, and when multiple antennas are included, it may support MIMO (Multiple Input Multiple Output) transmission and reception, and may also support beamforming.

[0257] The memory 3216 can store information processed by the processor 3220, software associated with the operation of the base station device 3200, an operating system, applications, etc., and can include components such as buffers.

[0258] The processor 3220 of the base station device 3200 may be configured to perform the operations of the base station in the embodiments described herein.

[0259] The terminal device 3250 may include a processor 3270, an antenna unit 3262, a transceiver 3264, and a memory 3266. As an example, in the present invention, the terminal device 3250 can communicate with the base station device 3200. As another example, in the present invention, the terminal device 3250 can perform sidelink communication with another terminal device. That is, the terminal device 3250 of the present invention refers to a device that can communicate with at least one of the base station device 3200 and another terminal device, and is not limited to communication with a specific device.

[0260] The processor 3270 performs baseband-related signal processing and may include an upper layer processing unit 3280 and a physical layer processing unit 3290. The upper layer processing unit 3280 may process operations of the MAC layer, the RRC layer, or higher layers. The physical layer processing unit 3290 may process operations of the PHY layer (e.g., downlink receive signal processing, uplink transmit signal processing). In addition to performing baseband-related signal processing, the processor 3270 may control the overall operation of the terminal device 3250.

[0261] The antenna unit 3262 may include one or more physical antennas, and when multiple antennas are included, may support MIMO transmission and reception, and may also support beamforming.

[0262] The memory 3266 can store information processed by the processor 3270, software associated with the operation of the terminal device 3250, an operating system, applications, etc., and can include components such as buffers.

[0263] The terminal device 3250 according to an embodiment of the present invention may be associated with a vehicle. For example, the terminal device 3250 may be built into, located in, or located on the vehicle. The terminal device 3250 according to the present invention may also be the vehicle itself. The terminal device 3250 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 3250 to which the present invention is applicable may include any of various types of communication devices that support interactive services using a sidelink for services such as Internet connection, service execution, navigation, real-time information, autonomous driving, safety, and hazard diagnosis. The terminal device 3250 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.

[0264] Here, vehicles to which the present invention is applicable may include autonomous vehicles, semi-autonomous vehicles, non-autonomous vehicles, etc. Meanwhile, although the terminal device 3250 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.

[0265] In addition, the terminal device 3250 according to an embodiment of the present invention may include various types of communication devices that can cooperate to support an interactive service using a sidelink. That is, the terminal device 3250 can be used not only to directly support an interactive service using a sidelink, but also as a cooperating device to support an interactive service using a sidelink.

[0266] 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-purpose processors, controllers, microcontrollers, microprocessors, etc.

[0267] 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.

[0268] 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]

[0269] The above may also be applied to other systems.

Claims

[Claim 1] 1. A method for conducting sidelink communication over an unlicensed spectrum, comprising: determining total resource elements (REs) for a physical sidelink shared channel (PSSCH); and determining a transport block size (TBS) based on the total REs.

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