Method and apparatus for determining TBS in unlicensed band

Abstract

A method of performing wireless communication by a first device and a device supporting the same are provided. The method may comprise the steps of: obtaining information related to a plurality of candidate start symbols in a slot for sidelink (SL) transmission, the plurality of candidate start symbols including a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) in the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

Description

Technical Field

[0001] The present disclosure relates to wireless communication systems. Background Art

[0002] Sidelink (SL) is a communication method that configures a direct link between User Equipment (UE) and exchanges voice or data directly between UEs without passing through a Base Station (BS). SL is being considered as a solution to the burden on base stations caused by the rapid increase in data traffic. V2X (Vehicle to Everything) is a communication technology that exchanges information with other vehicles, pedestrians, and objects equipped with infrastructure through wired / wireless communication. V2X can be divided into four types: V2V (Vehicle to Vehicle), V2I (Vehicle to Infrastructure), V2N (Vehicle to Network), and V2P (Vehicle to Pedestrian). V2X communication can be provided through the PC5 interface and / or Uu interface.

[0003] In addition, as more and more communication devices require greater communication capacity, the demand for mobile broadband communication that is enhanced compared to the previous radio access technology (RAT) is rising. Therefore, the reliability and delay-sensitive services or communication systems of user equipment (UE) are discussed. And, the next generation radio access technology based on improved mobile broadband communication, massive machine type communication (MTC), ultra-reliable low latency communication (URLLC), etc. can be called new radio access technology (RAT) or new radio (NR). Summary of the invention

[0004] Technical Solution

[0005] In an embodiment, a method for performing wireless communication by a first device is provided. The method may include: obtaining information related to a plurality of candidate start symbols in a time slot for side link (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) in the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0006] In an embodiment, a first device adapted to perform wireless communication is provided. The first device may include: at least one transceiver; at least one processor; and at least one memory, which is connected to the at least one processor and stores instructions, which, based on being executed by the at least one processor, cause the first device to perform operations, the operations including: obtaining information related to a plurality of candidate start symbols within a time slot for side link (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0007] In an embodiment, a processing device adapted to control a first device is provided. The processing device may include: at least one processor; and at least one memory connected to the at least one processor and storing instructions, the instructions causing the first device to perform operations based on being executed by the at least one processor, the operations including: obtaining information related to a plurality of candidate start symbols within a time slot for side link (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0008] In an embodiment, a non-transitory computer-readable storage medium storing instructions is provided. When the instructions are executed, a first device may perform operations, the operations including: obtaining information related to a plurality of candidate start symbols in a time slot for side link (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) in the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A communication structure that can be provided in a 6G system based on an embodiment of the present disclosure is shown.

[0010] Figure 2 An electromagnetic spectrum according to an embodiment of the present disclosure is shown.

[0011] Figure 3 The structure of the NR system according to the embodiment of the present disclosure is shown.

[0012] Figure 4 A radio protocol architecture according to an embodiment of the present disclosure is shown.

[0013] Figure 5 The structure of a radio frame of NR according to an embodiment of the present disclosure is shown.

[0014] Figure 6 The structure of the time slot of the NR frame based on the embodiment of the present disclosure is shown.

[0015] Figure 7 An example of a BWP based on an embodiment of the present disclosure is shown.

[0016] Figure 8 A process of performing V2X or SL communication by a UE based on a transmission mode according to an embodiment of the present disclosure is shown.

[0017] Fig. 9 Three cast types based on embodiments of the present disclosure are shown.

[0018] Fig.10 Interleaved RBs based on an embodiment of the present disclosure are shown.

[0019] Fig.11 The problem of increased delay time due to channel sensing failure is shown.

[0020] Fig.12 Multiple starting symbol positions or multiple starting time positions within a time slot according to an embodiment of the present disclosure are shown.

[0021] Fig.13 A process for a UE to determine a transport block size (TBS) according to an embodiment of the present disclosure is shown.

[0022] Fig.14 A method for a first device to perform wireless communication based on an embodiment of the present disclosure is shown.

[0023] Fig.15 A method for a second device to perform wireless communication based on an embodiment of the present disclosure is shown.

[0024] Fig.16 A communication system 1 according to an embodiment of the present disclosure is shown.

[0025] Fig.17 A wireless device according to an embodiment of the present disclosure is shown.

[0026] Fig.18 A signal processing circuit for transmitting a signal according to an embodiment of the present disclosure is shown.

[0027] Fig.19Another example of a wireless device according to an embodiment of the present disclosure is shown.

[0028] Fig. 20 A handheld device according to an embodiment of the present disclosure is shown.

[0029] Fig.21 A vehicle or autonomous vehicle according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0030] In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, in the present disclosure, "A or B" may be interpreted as "A and / or B". For example, in the present disclosure, "A, B or C" may mean "only A", "only B", "only C", or "any combination of A, B, C".

[0031] A slash ( / ) or a comma used in the present disclosure may mean "and / or". For example, "A / B" may mean "A and / or B". Thus, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0032] In the present disclosure, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, in the present disclosure, the expression "at least one of A or B" or "at least one of A and / or B" may be interpreted as "at least one of A and B".

[0033] In addition, in the present disclosure, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B and / or C" may mean "at least one of A, B, and C".

[0034] In addition, brackets used in the present disclosure may mean "for example". Specifically, when indicated as "control information (PDCCH)", this may mean that "PDCCH" is proposed as an example of "control information". In other words, the "control information" of the present disclosure is not limited to "PDCCH", and "PDDCH" may be proposed as an example of "control information". Specifically, when indicated as "control information (ie, PDCCH)", this may also mean that "PDCCH" is proposed as an example of "control information".

[0035] In the following description, "when, if, or in the event of" may be replaced with "based on".

[0036] The technical features respectively described in one drawing in the present disclosure may be implemented separately or may be implemented simultaneously.

[0037] In the present disclosure, the higher layer parameter may be a parameter configured, preconfigured or predefined for the UE. For example, the base station or the network may send the higher layer parameter to the UE. For example, the higher layer parameter may be sent via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0038] The techniques described below may be used in various wireless communication systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc. CDMA may be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA-2000. TDMA may be implemented using radio technologies such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented using radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Evolved UTRA (E-UTRA), etc. IEEE 802.16m is an evolved version of IEEE 802.16e and provides backward compatibility for systems based on IEEE 802.16e. UTRA is part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) that uses E-UTRA. 3GPP LTE uses OFDMA in the downlink and SC-FDMA in the uplink. LTE-Advanced (LTE-A) is an evolution of LTE.

[0039] 5G NR is a subsequent technology of LTE-A corresponding to a new mobile communication system with high performance, low latency, high availability, etc. 5G NR can use all available spectrum resources including low frequency bands less than 1 GHz, intermediate frequency bands from 1 GHz to 10 GHz, and high frequency (millimeter wave) above 24 GHz.

[0040] The 6G (wireless communication) system has objectives such as (i) very high data rates per device, (ii) very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) reduced energy consumption of battery-free IoT devices, (vi) ultra-reliable connectivity, and (vii) networked intelligence with machine learning capabilities. The vision of the 6G system may include four aspects such as intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity, and the 6G system may meet the requirements shown in the following Table 1. That is, Table 1 shows the requirements of the 6G system.

[0041] [Table 1]

[0042] Peak data rate per device 1 Tbps E2E Latency 1 ms Maximum spectral efficiency 100bps / Hz Mobility support Up to 1000km / h Satellite Integration Completely AI Completely Autonomous Vehicles Completely XR Completely Tactile communication Completely

[0043] The 6G system may have key factors such as enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), massive machine type communications (mMTC), AI-integrated communications, tactile Internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0044] Figure 1 A communication structure that can be provided in a 6G system based on an embodiment of the present disclosure is shown. Figure 1 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0045] The 6G system will have 50 times higher simultaneous wireless communication connectivity than the 5G wireless communication system. URLLC, which is the main function of 5G, will become a more important technology by providing an end-to-end latency of less than 1ms in 6G communication. Unlike the frequently used domain spectrum efficiency, the 6G system can have better volume spectrum efficiency. The 6G system can provide advanced battery technology for energy harvesting and very long battery life, and therefore mobile devices may not need to be charged separately in the 6G system. In 6G, new network characteristics may be as follows.

[0046] - Satellite-integrated network: To provide global mobile constellations, 6G will be integrated with satellites. Integrating ground waves, satellites, and public networks into one wireless communication system could be very important for 6G.

[0047] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is innovative, and wireless evolution may be updated from "connected things" to "connected intelligence." AI can be applied in every step of the communication process (or every signal processing process to be described below).

[0048] - Seamless integration of wireless information and energy transfer: 6G wireless networks can transfer power to facilitate charging the batteries of devices such as smartphones and sensors. Therefore, wireless information and energy transfer (WIET) will be integrated.

[0049] - Ubiquitous hyper-3D connectivity: Access to networks and core network functions from drones and very low earth orbit satellites will establish hyper-3D connectivity in 6G ubiquitous.

[0050] Among the new network features of 6G, several general requirements are as follows.

[0051] - Small cell network: The concept of small cell network is introduced to improve the received signal quality as a result of the improvement of the throughput, energy efficiency and spectrum efficiency of the cellular system. Therefore, small cell network is an essential feature of 5G and beyond 5G (5GB) communication system. Therefore, 6G communication system also adopts the characteristics of small cell network.

[0052] - Ultra-dense heterogeneous network: Ultra-dense heterogeneous network will be another important feature of 6G communication system. Multi-tier network composed of heterogeneous networks improves overall QoS and reduces costs.

[0053] - High Capacity Backhaul: Backhaul connectivity is characterized by a high capacity backhaul network in order to support high capacity traffic. High-speed optical fiber and free space optics (FSO) systems can be possible solutions to this problem.

[0054] - Radar technology integrated with mobile technology: High-precision positioning (or location-based services) through communication is one of the functions of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0055] - Software-based and virtualized: Software-based and virtualized are two important functions that are fundamental to the design process in 5Gb networks in order to ensure flexibility, reconfigurability, and programmability.

[0056] The core implementation technology of the 6G system is described below.

[0057] - Artificial Intelligence (AI): As the most important and newly introduced technology in 6G system is AI. AI is not involved in 4G system. 5G system will support partial or very limited AI. However, 6G system will support AI for full automation. Advances in machine learning will create smarter networks for real-time communication in 6G. When AI is introduced into communication, real-time data transmission can be simplified and improved. AI can use countless analyses to determine the way to perform complex target tasks. That is, AI can increase efficiency and reduce processing delays. Time-consuming operations such as switching, network selection, and resource scheduling can be performed instantly by AI. AI can also play an important role in M2M, machine to human, and human to machine. In addition, AI may be instant communication in brain-computer interface (BCI). AI-based communication systems can be supported by metamaterials, smart structures, smart networks, smart devices, smart cognitive radios, self-maintaining wireless networks, and machine learning.

[0058] - Terahertz (THz) communication: Data rates can be increased by increasing bandwidth. This can be achieved by using sub-TH communication with wide bandwidth and applying advanced massive MIMO technology. THz waves are called submillimeter radiation, generally indicating a frequency band between 0.1THz and 10THz with a corresponding wavelength in the range of 0.03mm to 3mm. The band range of 100GHz to 300GHz (sub-THz band) is regarded as the main part of the THz band for cellular communication. When the sub-THz band is added to the millimeter wave band, the 6G cellular communication capacity increases. 300GHz to 3THz of the defined THz band is in the far infrared (IR) band. The band of 300GHz to 3THz is part of the optical band, but is located at the boundary of the optical band and immediately after the RF band. Therefore, the band of 300GHz to 3THz has similarities with RF. Figure 2 An electromagnetic spectrum according to an embodiment of the present disclosure is shown. Figure 2 The embodiments of can be combined with various embodiments of the present disclosure. The main features of THz communication include (i) a wide bandwidth that can be used to support very high data rates; and (ii) high path loss occurs at high frequencies (highly directional antennas are essential). The narrow beamwidth generated in highly directional antennas reduces interference. The small wavelength of THz signals allows a larger number of antenna elements to be integrated with devices and BSs operating in this band. Therefore, advanced adaptive placement techniques that can overcome range limitations can be used.

[0059] - Massive MIMO technology (Large MIMO)

[0060] - Holographic Beamforming (HBF)

[0061] - Optical Wireless Technology

[0062] - Free Space Optical Backhaul Network (FSO Backhaul Network)

[0063] - Non-Terrestrial Network (NTN)

[0064] - Quantum communication

[0065] - No cellular communication

[0066] - Integration of wireless information and power transmission

[0067] - Integration of wireless communication and sensing

[0068] -Integrated access and backhaul network

[0069] -Big Data Analysis

[0070] -Reconfigurable smart surface

[0071] - Metaverse

[0072] - Blockchain

[0073] - Unmanned Aerial Vehicles (UAVs): Unmanned aerial vehicles (UAVs) or drones will be an important factor in 6G wireless communications. In most cases, high-speed data wireless connections are provided using UAV technology. A base station entity is installed inside the UAV to provide cellular connectivity. UAVs have certain features not found in fixed base station infrastructure, such as ease of deployment, robust line-of-sight links, and freedom of mobility control. During emergencies such as natural disasters, it is not economically feasible to deploy terrestrial telecommunication infrastructure and sometimes it is impossible to provide services in turbulent environments. UAVs can easily handle such situations. UAVs will become a new paradigm in the field of wireless communications. This technology promotes the three basic requirements of wireless networks, such as eMBB, URLLC, and mMTC. UAVs can also be used for a variety of purposes, such as network connectivity improvement, fire detection, disaster emergency services, security and monitoring, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most important technologies for 6G communications.

[0074] - Autonomous driving (self-driving): In order to achieve perfect autonomous driving, it is necessary to inform each other of dangerous situations through communication between vehicles and vehicles, to check information such as parking information location and signal change time through communication between vehicles and infrastructure such as parking lots and / or traffic lights. Vehicle-to-Everything (V2X) is a core element for building an autonomous driving infrastructure, and is a technology for vehicles to communicate and share with various elements in the road, such as vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I). In order to maximize the performance of autonomous driving and ensure high safety, high transmission speed and low latency technology are required. In addition, in order to directly control vehicles in dangerous situations and actively intervene in vehicle driving at a level beyond warning or guidance messages to the driver, autonomous driving is expected to be maximized in 6G, which has faster transmission speeds and lower latency than 5G, because the amount of information to be sent and received is large.

[0075] For the sake of clarity of the specification, 5G NR is mainly described, but the technical ideas according to the embodiments of the present disclosure are not limited thereto. Various embodiments of the present disclosure can also be applied to 6G communication systems.

[0076] Figure 3 The structure of the NR system according to the embodiment of the present disclosure is shown. Figure 3 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0077] refer to Figure 3 , the next generation radio access network (NG-RAN) may include a BS 20 that provides user plane and control plane protocol terminations to the UE 10. For example, the BS 20 may include a next generation Node B (gNB) and / or an evolved Node B (eNB). For example, the UE 10 may be fixed or mobile and may be referred to as other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. For example, the BS may be referred to as a fixed station that communicates with the UE 10 and may be referred to as other terms such as a base transceiver system (BTS), an access point (AP), etc.

[0078] Figure 3 The embodiment of illustrates a case where only gNB is included. The BSs 20 may be connected to each other via an Xn interface. The BSs 20 may be connected to each other via a fifth generation (5G) core network (5GC) and an NG interface. More specifically, the BSs 20 may be connected to an access and mobility management function (AMF) 30 via an NG-C interface, and may be connected to a user plane function (UPF) 30 via an NG-U interface.

[0079] The radio interface protocol layer between the UE and the network can be classified into the first layer (L1), the second layer (L2), and the third layer (L3) based on the lower three layers of the open system interconnection (OSI) model known in the communication system. Among them, the physical (PHY) layer belonging to the first layer provides an information transmission service using a physical channel, and the radio resource control (RRC) layer located at the third layer controls the radio resources between the UE and the network. To this end, the RRC layer exchanges RRC messages between the UE and the BS layer.

[0080] Figure 4 A radio protocol architecture according to an embodiment of the present disclosure is shown. Figure 4 The embodiments of can be combined with various embodiments of the present disclosure. Specifically, Figure 4 (a) shows a radio protocol stack for the user plane of Uu communication, and Figure 4 (b) shows the radio protocol stack of the control plane for Uu communication. Figure 4 (c) shows the radio protocol stack of the user plane for SL communication, and Figure 4 (d) shows the radio protocol stack of the control plane for SL communication.

[0081] refer to Figure 4 , the physical layer provides information transfer services to the upper layer through the physical channel. The physical layer is connected to the medium access control (MAC) layer, which is the upper layer of the physical layer, through the transport channel. Data is transferred between the MAC layer and the physical layer through the transport channel. The transport channel is classified according to how the data is transmitted through the radio interface and what characteristics of the data it transmits.

[0082] Data is transmitted between different physical layers (ie, the PHY layer of the transmitter and the PHY layer of the receiver) through a physical channel. The physical channel may be modulated using an orthogonal frequency division multiplexing (OFDM) scheme and uses time and frequency as radio resources.

[0083] The MAC layer provides services to the Radio Link Control (RLC) layer, which is a higher layer of the MAC layer, via logical channels. The MAC layer provides a function of mapping multiple logical channels to multiple transport channels. The MAC layer also provides a function of logical channel multiplexing by mapping multiple logical channels to a single transport channel. The MAC layer provides data transmission services through logical channels.

[0084] The RLC layer performs concatenation, segmentation, and reassembly of Radio Link Control Service Data Units (RLC SDUs). In order to ensure different Quality of Service (QoS) required by Radio Bearers (RBs), the RLC layer provides three types of operation modes, namely, Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through Automatic Repeat Request (ARQ).

[0085] The Radio Resource Control (RRC) layer is defined only in the control plane. The RRC layer is used to control logical channels, transport channels, and physical channels associated with the configuration, reconfiguration, and release of RBs. RBs are logical paths for data transmission between UEs and the network provided by the first layer (i.e., the physical layer or PHY layer) and the second layer (i.e., the MAC layer, the RLC layer, the packet data convergence protocol (PDCP) layer, and the service data adaptation protocol (SDAP) layer).

[0086] The functions of the Packet Data Convergence Protocol (PDCP) in the user plane include transmission of user data, header compression and encryption. The functions of the Packet Data Convergence Protocol (PDCP) in the control plane include transmission and encryption / integrity protection of control plane data.

[0087] The Service Data Adaptation Protocol (SDAP) layer is defined only in the user plane. The SDAP layer performs mapping between Quality of Service (QoS) flows and Data Radio Bearers (DRBs) and QoS Flow ID (QFI) marking in both DL and UL packets.

[0088] Configuration of RB means a process for specifying radio protocol layers and channel attributes to provide a specific service and for determining corresponding detailed parameters and operation methods. RBs can then be classified into two types, namely, signaling radio bearers (SRBs) and data radio bearers (DRBs). SRBs are used as a path for sending RRC messages in the control plane, and DRBs are used as a path for sending user data in the user plane.

[0089] When an RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in the RRC connected (RRC_CONNECTED) state, otherwise the UE may be in the RRC idle (RRC_IDLE) state. In the case of NR, an RRC inactive (RRC_INACTIVE) state is additionally defined, and the UE in the RRC_INACTIVE state may maintain the connection with the core network and release its connection with the BS.

[0090] Data is sent from the network to the UE via a downlink transport channel. Examples of downlink transport channels include a broadcast channel (BCH) for sending system information and a downlink shared channel (SCH) for sending other user traffic or control messages. Traffic or control messages for downlink multicast or broadcast services may be sent via a downlink SCH or may be sent via a separate downlink multicast channel (MCH). In addition, uplink transport channels for sending (or transmitting) data from the UE to the network include a random access channel (RACH) for sending initial control messages and an uplink shared channel (SCH) for sending other user traffic or control messages.

[0091] Examples of logical channels belonging to a higher layer of a transport channel and mapped to the transport channel may include a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), a multicast traffic channel (MTCH), etc.

[0092] Figure 5 The structure of a radio frame of NR according to an embodiment of the present disclosure is shown. Figure 5 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0093] refer to Figure 5 In NR, a radio frame can be used to perform uplink and downlink transmissions. The length of a radio frame is 10 ms and can be defined as consisting of two half frames (HF). A half frame can include five 1 ms subframes (SF). A subframe (SF) can be divided into one or more slots, and the number of slots within a subframe can be determined by a subcarrier spacing (SCS). Each slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0094] When a normal CP is used, each time slot may include 14 symbols. When an extended CP is used, each time slot may include 12 symbols. Herein, a symbol may include an OFDM symbol (or a CP-OFDM symbol) and a single carrier-FDMA (SC-FDMA) symbol (or a discrete Fourier transform spread OFDM (DFT-s-OFDM) symbol).

[0095] Table 2 shown below represents the number of symbols (N) per slot based on the SCS configuration (μ) in the case of using a normal CP or an extended CP. slot symb ), the number of time slots per frame (N frame,μ slot ) and the number of time slots per subframe (N subframe ,μ slot ).

[0096] [Table 2]

[0097]

[0098] In the NR system, OFDM (A) parameter sets (e.g., SCS, CP length, etc.) may be configured differently between multiple cells integrated into one UE. Therefore, the (absolute time) duration (or interval) of a time resource (e.g., subframe, time slot, or TTI) (collectively referred to as a time unit (TU) for simplicity) consisting of the same number of symbols may be configured differently in the integrated cells.

[0099] In NR, multiple parameter sets or SCSs can be supported to support various 5G services. For example, with an SCS of 15 kHz, a wide range of traditional cellular bands can be supported, and with an SCS of 30 kHz / 60 kHz, dense cities, lower latency, and wider carrier bandwidths can be supported. With an SCS of 60 kHz or higher, bandwidths greater than 24.25 GHz can be used to overcome phase noise.

[0100] The NR frequency band may be defined as two different types of frequency ranges. The two different types of frequency ranges may be FR1 and FR2. The values ​​of the frequency ranges may be changed (or varied), for example, the two different types of frequency ranges may be as shown in Table 3 below. Among the frequency ranges used in the NR system, FR1 may mean "a range below 6 GHz", and FR2 may mean "a range above 6 GHz", and may also be referred to as millimeter wave (mmW).

[0101] [Table 3]

[0102] Frequency range specification Corresponding frequency range Subcarrier spacing (SCS) FR1 450 MHz – 6000 MHz 15, 30, 60kHz FR2 24250 MHz – 52600 MHz 60, 120, 240 kHz

[0103] As described above, the value of the frequency range in the NR system may be changed (or varied). For example, as shown in Table 4 below, FR1 may include a bandwidth in the range of 410 MHz to 7125 MHz. More specifically, FR1 may include frequency bands of 6 GHz (or 5850, 5900, 5925 MHz, etc.) and higher. For example, the frequency bands of 6 GHz (or 5850, 5900, 5925 MHz, etc.) and higher included in FR1 may include unlicensed bands. The unlicensed bands may be used for various purposes, for example, the unlicensed bands are used for vehicle-specific communications (e.g., autonomous driving).

[0104] [Table 4]

[0105] Frequency range specification Corresponding frequency range Subcarrier spacing (SCS) FR1 410MHz – 7125MHz 15, 30, 60kHz FR2 24250MHz – 52600MHz 60, 120, 240kHz

[0106] Figure 6 The structure of the time slot of the NR frame according to an embodiment of the present disclosure is shown. Figure 6 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0107] refer to Figure 6 , a time slot includes multiple symbols in the time domain. For example, in the case of normal CP, one time slot may include 14 symbols. For example, in the case of extended CP, one time slot may include 12 symbols. Alternatively, in the case of normal CP, one time slot may include 7 symbols. However, in the case of extended CP, one time slot may include 6 symbols.

[0108] A carrier includes a plurality of subcarriers in the frequency domain. A resource block (RB) may be defined as a plurality of consecutive subcarriers in the frequency domain (e.g., 12 subcarriers). A bandwidth part (BWP) may be defined as a plurality of consecutive (physical) resource blocks ((P)RBs) in the frequency domain, and a BWP may correspond to a parameter set (e.g., SCS, CP length, etc.). A carrier may include a maximum of N BWPs (e.g., 5 BWPs). Data communication may be performed via an activated BWP. Each element may be referred to as a resource element (RE) in a resource grid, and a complex symbol may be mapped to each element.

[0109] Hereinafter, a bandwidth part (BWP) and a carrier will be described in detail.

[0110] A BWP may be a contiguous set of physical resource blocks (PRBs) within a given parameter set. A PRB may be selected from a contiguous set of common resource blocks (CRBs) for a given parameter set on a given carrier.

[0111] For example, the BWP may be at least any one of an active BWP, an initial BWP, and / or a default BWP. For example, the UE may not monitor the downlink radio link quality in a DL BWP other than an activated DL BWP on a primary cell (PCell). For example, the UE may not receive a PDCCH, a physical downlink shared channel (PDSCH), or a channel state information-reference signal (CSI-RS) (excluding RRM) other than an activated DL BWP. For example, the UE may not trigger a channel state information (CSI) report for an unactivated DL BWP. For example, the UE may not send a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) other than an activated UL BWP. For example, in the case of a downlink, the initial BWP may be given as a set of contiguous RBs for a remaining minimum system information (RMSI) control resource set (CORESET) (configured by a physical broadcast channel (PBCH)). For example, in the case of an uplink, the initial BWP may be given by a system information block (SIB) for a random access procedure. For example, a default BWP may be configured by a higher layer. For example, the initial value of the default BWP may be an initial DL BWP.For power saving, if the UE cannot detect downlink control information (DCI) during a specified period, the UE may switch the UE's active BWP to the default BWP.

[0112] In addition, a BWP may be defined for SL. The same SL BWP may be used in transmission and reception. For example, a transmitting UE may send a SL channel or SL signal on a specific BWP, and a receiving UE may receive a SL channel or SL signal on a specific BWP. In a licensed carrier, the SL BWP may be defined separately from the Uu BWP, and the SL BWP may have configuration signaling separate from the Uu BWP. For example, the UE may receive a configuration for the SL BWP from the BS / network. For example, the UE may receive a configuration for the Uu BWP from the BS / network. SLBWP is (pre-)configured in the carrier for out-of-coverage NR V2X UEs and RRC_IDLE UEs. For UEs in RRC_CONNECTED mode, at least one SL BWP may be activated in the carrier.

[0113] Figure 7 An example of a BWP according to an embodiment of the present disclosure is shown. Figure 7 The embodiments of can be combined with various embodiments of the present disclosure. Assume that Figure 7 In the embodiment, the number of BWPs is 3.

[0114] refer to Figure 7, a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier frequency band to the other end thereof. Additionally, a PRB may be a resource block numbered within each BWP. Point A may indicate a common reference point of the resource block grid.

[0115] It can be obtained by point A, the offset relative to point A (N start BWP ) and bandwidth (N size BWP ) to configure the BWP. For example, point A may be an external reference point of the PRBs of the carrier, and subcarrier 0 of all parameter sets (e.g., all parameter sets supported by the network on the corresponding carrier) are aligned in point A. For example, the offset may be the PRB distance between the lowest subcarrier within a given parameter set and point A. For example, the bandwidth may be the number of PRBs within a given parameter set.

[0116] Hereinafter, V2X or SL communication will be described.

[0117] The side link synchronization signal (SLSS) may include a primary side link synchronization signal (PSSS) and a secondary side link synchronization signal (SSSS) as SL specific sequences. The PSSS may be referred to as a side link primary synchronization signal (S-PSS), and the SSSS may be referred to as a side link secondary synchronization signal (S-SSS). For example, an M sequence of length 127 may be used for the S-PSS, and a Gold sequence of length 127 may be used for the S-SSS. For example, the UE may use the S-PSS for initial signal detection and synchronization acquisition. For example, the UE may use the S-PSS and the S-SSS for acquisition of detailed synchronization and for detection of a synchronization signal ID.

[0118] The physical sidelink broadcast channel (PSBCH) may be a (broadcast) channel for transmitting default (system) information that the UE must first know before SL signal transmission / reception. For example, the default information may be information related to SLSS, duplex mode (DM), time division duplex (TDD) uplink / downlink (UL / DL) configuration, information related to resource pool, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in order to evaluate PSBCH performance, in NR V2X, the payload size of PSBCH may be 56 bits, including a 24-bit cyclic redundancy check (CRC).

[0119] S-PSS, S-SSS, and PSBCH can be included in a block format that supports periodic transmission (e.g., SL synchronization signal (SS) / PSBCH block, hereinafter, sidelink synchronization signal block (S-SSB)). The S-SSB can have the same parameter set (i.e., SCS and CP length) as the physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH) in the carrier, and the transmission bandwidth can exist within the (pre-) configured sidelink (SL) BWP. For example, the S-SSB can have a bandwidth of 11 resource blocks (SBs). For example, the PSBCH can exist across 11 RBs. In addition, the frequency position of the S-SSB can be (pre-) configured. Therefore, the UE does not have to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0120] Figure 8 A process of performing V2X or SL communication by a UE based on a transmission mode according to an embodiment of the present disclosure is shown. Figure 8 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure. In various embodiments of the present disclosure, the transmission mode may be referred to as a mode or a resource allocation mode. Hereinafter, for ease of explanation, in LTE, the transmission mode may be referred to as an LTE transmission mode. In NR, the transmission mode may be referred to as an NR resource allocation mode.

[0121] For example, Figure 8 (a) in FIG. 1 shows UE operations related to LTE transmission mode 1 or LTE transmission mode 3. Alternatively, for example, Figure 8 (a) in FIG. 1 shows UE operations related to NR resource allocation mode 1. For example, LTE transmission mode 1 may be applied to conventional SL communication, and LTE transmission mode 3 may be applied to V2X communication.

[0122] For example, Figure 8 (b) in FIG. 4 shows UE operations related to LTE transmission mode 2 or LTE transmission mode 4. Alternatively, for example, Figure 8 (b) in FIG. 1 shows UE operation related to NR resource allocation mode 2.

[0123] refer to Figure 8 (a), in LTE transmission mode 1, LTE transmission mode 3 or NR resource allocation mode 1, the base station may schedule SL resources to be used by the UE for SL transmission. For example, in step S800, the base station may send information related to the SL resources and / or information related to the UL resources to the first UE. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources used to report SL HARQ feedback to the base station.

[0124] For example, the first UE may receive information related to dynamic grant (DG) resources and / or information related to configuration grant (CG) resources from the base station. For example, the CG resources may include CG type 1 resources or CG type 2 resources. In the present disclosure, the DG resources may be resources configured / allocated to the first UE by the base station through downlink control information (DCI). In the present disclosure, the CG resources may be (periodic) resources configured / allocated to the first UE by the base station through DCI and / or RRC messages. For example, in the case of CG type 1 resources, the base station may send an RRC message including information related to the CG resources to the first UE. For example, in the case of CG type 2 resources, the base station may send an RRC message including information related to the CG resources to the first UE, and the base station may send a DCI related to the activation or release of the CG resources to the first UE.

[0125] In step S810, the first UE may send a PSCCH (e.g., sidelink control information (SCI) or a first-level SCI) to a second UE based on resource scheduling. In step S820, the first UE may send a PSSCH (e.g., a second-level SCI, a MAC PDU, data, etc.) related to the PSCCH to the second UE. In step S830, the first UE may receive a PSFCH related to the PSCCH / PSSCH from the second UE. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second UE via the PSFCH. In step S840, the first UE may send / report the HARQ feedback information to the base station via the PUCCH or PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on the HARQ feedback information received from the second UE. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on a preconfigured rule. For example, the DCI may be a DCI for SL scheduling. For example, the format of DCI may be DCI format 3_0 or DCI format 3_1.

[0126] refer to Figure 8(b) in LTE transmission mode 2, LTE transmission mode 4 or NR resource allocation mode 2, the UE may determine the SL transmission resources within the SL resources configured by the base station / network or the preconfigured SL resources. For example, the configured SL resources or the preconfigured SL resources may be a resource pool. For example, the UE may autonomously select or schedule resources for SL transmission. For example, the UE may perform SL communication by autonomously selecting resources within the configured resource pool. For example, the UE may autonomously select resources within the selection window by performing a sensing process and a resource (re)selection process. For example, sensing may be performed in units of subchannels. For example, in step S810, the first UE, which has selected resources from the resource pool by itself, may send a PSCCH (e.g., sidelink control information (SCI) or a first-level SCI) to a second UE by using the resources. In step S820, the first UE may send a PSSCH (e.g., a second-level SCI, a MAC PDU, data, etc.) related to the PSCCH to the second UE. In step S830, the first UE may receive a PSFCH related to the PSCCH / PSSCH from the second UE.

[0127] refer to Figure 8 (a) or (b), for example, the first UE may send the SCI to the second UE via the PSCCH. Alternatively, for example, the first UE may send two consecutive SCIs (e.g., level 2 SCIs) to the second UE via the PSCCH and / or the PSSCH. In this case, the second UE may decode the two consecutive SCIs (e.g., level 2 SCIs) to receive the PSSCH from the first UE. In the present disclosure, the SCI sent via the PSCCH may be referred to as the first SCI, the first SCI, the first level SCI, or the first level SCI format, and the SCI sent via the PSSCH may be referred to as the second SCI, the second SCI, the second level SCI, or the second level SCI format. For example, the first level SCI format may include SCI format 1-A, and the second level SCI format may include SCI format 2-A and / or SCI format 2-B.

[0128] Hereinafter, an example of SCI format 1-A will be described.

[0129] SCI format 1-A is used for scheduling PSSCH and secondary SCI on PSSCH.

[0130] The following information is sent via SCI Format 1-A:

[0131] - Priority - 3 bits

[0132] - Frequency resource assignment - When the value of the higher layer parameter sl-MaxNumPerReserve is configured as 2, ceiling(log2(N SL subChannel (N SL subChannel +1) / 2)) bits; otherwise, when the value of the higher layer parameter sl-MaxNumPerReserve is configured as 3, the ceiling log2 (N SL subChannel (N SL subChannel +1)(2N SL subChannel +1) / 6) bits.

[0133] - Time Resource Assignment - 5 bits when the higher layer parameter sl-MaxNumPerReserve is configured with a value of 2; otherwise, 9 bits when the higher layer parameter sl-MaxNumPerReserve is configured with a value of 3

[0134] -Resource reservation period - If the higher layer parameter sl-MultiReserveResource is configured, the ceiling (log2N rsv_period ) bits, where N rsv_period is the number of entries in the higher layer parameter sl-ResourceReservePeriodList; otherwise, 0

[0135] -DMRS pattern -ceiling(log2N pattern ) bits, where N pattern is the number of DMRS patterns configured by the higher layer parameter sl-PSSCH-DMRS-TimePatternList

[0136] - Second level SCI format - 2 bits, as defined in Table 5

[0137] - Beta_offset indicator - 2 bits, as provided by the higher layer parameter sl-BetaOffsets2ndSCI

[0138] - Number of DMRS ports - 1 bit, as defined in Table 6

[0139] - Modulation and coding scheme - 5 bits

[0140] - Additional MCS table indicator - 1 bit if one MCS table is configured by the higher layer parameter sl-Additional-MCS-Table; 2 bits if two MCS tables are configured by the higher layer parameter sl-Additional-MCS-Table; otherwise, 0 bit

[0141] -PSFCH overhead indication - 1 bit if higher layer parameter sl-PSFCH-Period = 2 or 4; otherwise, 0 bit

[0142] - Reserved bits - The number of bits determined by the higher layer parameter sl-NumReservedBits, whose value is set to zero.

[0143] [Table 5]

[0144] Value of the second level SCI format field Second level SCI format 00 SCI Format 2-A 01 SCI Format 2-B 10 reserve 11 reserve

[0145] [Table 6]

[0146] Value of the Number of DMRS Ports field Antenna Port 0 1000 1 1000 and 1001

[0147] Hereinafter, an example of SCI format 2-A will be described.

[0148] SCI format 2-A is used for decoding of PSSCH and is used together with the HARQ operation when the HARQ-ACK information includes ACK or NACK, when the HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information.

[0149] The following information is sent via SCI Format 2-A:

[0150] -HARQ process number - 4 bits

[0151] - New data indicator - 1 bit

[0152] - Redundancy version - 2 bits

[0153] - Source ID - 8 bits

[0154] -Destination ID - 16 bits

[0155] -HARQ feedback enable / disable indicator - 1 bit

[0156] - Broadcast Type Indicator - 2 bits, as defined in Table 7

[0157] -CSI request - 1 bit

[0158] [Table 7]

[0159] The value of the playback type indicator Broadcast Type 00 broadcast 01 Multicast when HARQ-ACK information includes ACK or NACK 10 Unicast 11 Multicast when HARQ-ACK information includes only NACK

[0160] Hereinafter, an example of SCI format 2-B will be described.

[0161] For HARQ operation, when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information, SCI format 2-B is used for decoding of PSSCH.

[0162] The following information is sent via SCI Format 2-B:

[0163] -HARQ process number - 4 bits

[0164] - New data indicator - 1 bit

[0165] - Redundancy version - 2 bits

[0166] - Source ID - 8 bits

[0167] -Destination ID - 16 bits

[0168] -HARQ feedback enable / disable indicator - 1 bit

[0169] - Region ID - 12 digits

[0170] -Communication range requirement - 4 bits determined by the higher layer parameter sl-ZoneConfigMCR-Index

[0171] refer to Figure 8 (a) or (b), in step S830, the first UE may receive the PSFCH. For example, the first UE and the second UE may determine the PSFCH resources, and the second UE may send the HARQ feedback to the first UE using the PSFCH resources.

[0172] refer to Figure 8 (a), in step S840, the first UE may send SL HARQ feedback to the base station through the PUCCH and / or the PUSCH.

[0173] Fig. 9 Three broadcast types according to embodiments of the present disclosure are shown. Fig. 9 The embodiments of can be combined with various embodiments of the present disclosure. Specifically, Fig. 9 (a) shows broadcast type SL communication, Fig. 9 (b) shows unicast type SL communication, and Fig. 9 (c) in the figure shows multicast SL communication. In the case of unicast SL communication, the UE can perform one-to-one communication with another UE. In the case of multicast SL transmission, the UE can perform SL communication with one or more UEs in the group to which the UE belongs. In various embodiments of the present disclosure, SL groupcast communication may be replaced by SL multicast communication, SL one-to-many communication, etc.

[0174] Hereinafter, a hybrid automatic repeat request (HARQ) process will be described.

[0175] For example, SL HARQ feedback may be enabled for unicast. In this case, in non-code block group (non-CBG) operation, if the receiving UE decodes the PSCCH whose target is the receiving UE and if the receiving UE successfully decodes the transport block associated with the PSCCH, the receiving UE may generate a HARQ-ACK. In addition, the receiving UE may send a HARQ-ACK to the transmitting UE. Otherwise, if the receiving UE fails to successfully decode the transport block after decoding the PSCCH whose target is the receiving UE, the receiving UE may generate a HARQ-NACK. In addition, the receiving UE may send a HARQ-NACK to the transmitting UE.

[0176] For example, SL HARQ feedback may be enabled for multicast.For example, in non-CBG operation, two HARQ feedback options may be supported for multicast.

[0177] (1) Multicast Option 1: After the receiving UE decodes the PSCCH whose target is the receiving UE, if the receiving UE cannot decode the transport block associated with the PSCCH, the receiving UE may send HARQ-NACK to the transmitting UE through the PSFCH. Otherwise, if the receiving UE decodes the PSCCH whose target is the receiving UE and if the receiving UE successfully decodes the transport block associated with the PSCCH, the receiving UE may not send HARQ-ACK to the transmitting UE.

[0178] (2) Multicast Option 2: After the receiving UE decodes the PSCCH whose destination is the receiving UE, if the receiving UE cannot decode the transport block associated with the PSCCH, the receiving UE can send HARQ-NACK to the transmitting UE through the PSFCH. In addition, if the receiving UE decodes the PSCCH whose destination is the receiving UE and if the receiving UE successfully decodes the transport block associated with the PSCCH, the receiving UE can send HARQ-ACK to the transmitting UE through the PSFCH.

[0179] For example, if multicast option 1 is used for SL HARQ feedback, all UEs performing multicast communication may share PSFCH resources. For example, UEs belonging to the same group may send HARQ feedback by using the same PSFCH resources.

[0180] For example, if multicast option 2 is used for SL HARQ feedback, each UE performing multicast communication may use different PSFCH resources for HARQ feedback transmission. For example, UEs belonging to the same group may send HARQ feedback by using different PSFCH resources.

[0181] In the present disclosure, HARQ-ACK may be referred to as ACK, ACK information, or positive ACK information, and HARQ-NACK may be referred to as NACK, NACK information, or negative ACK information.

[0182] Hereinafter, the UE procedure for reporting HARQ-ACK on the secondary link will be described.

[0183] Can be in N PSSCH subch The UE is instructed by the SCI format of the scheduled PSSCH reception in one or more of the subchannels to send a PSFCH with HARQ-ACK information in response to the PSSCH reception. The UE provides HARQ-ACK information including ACK or NACK or only NACK.

[0184] The number of slots in the resource pool used for the PSFCH transmission opportunity resource period may be provided to the UE by sl-PSFCH-Period-r16. If this number is zero, PSFCH transmission from the UE in the resource pool is disabled. The UE expects that if kmod N PSFCH PSSCH = 0, then time slot t' k SL (0≤k <T' max ) has PSFCH transmission opportunity resources, where t' k SL is the time slot belonging to the resource pool, T' max is the number of time slots belonging to the resource pool within 10240 milliseconds, and N PSFCH PSSCH Provided by sl-PSFCH-Period-r16. The UE may be instructed by higher layers not to transmit PSFCH in response to PSSCH reception. If the UE receives PSSCH in a resource pool and the HARQ Feedback Enable / Disable Indicator field in the associated SCI Format 2-A or SCI Format 2-B has a value of 1, the UE provides HARQ-ACK information in the PSFCH transmission in the resource pool. The UE transmits PSFCH in the first slot after at least the number of slots provided by sl-MinTimeGapPSFCH-r16 of the resource pool that includes PSFCH resources and after the last slot of PSSCH reception.

[0185] sl-PSFCH-RB-Set-r16 provides the UE with the M in the resource pool for PSFCH transmission in the PRB of the resource pool. PSFCH PRB,set The number of subchannels N in the resource pool provided by sl-NumSubchannel subchand less than or equal to N PSFCH PSSCH The UE sets M to the number of PSSCH time slots associated with the PSFCH time slot. PRB,set PSFCH [(i+j·N PSFCH PSSCH )·M PSFCH subch,slot , (i+1+j·N PSFCH PSSCH )·M PSFCH subch,slot -1] PRBs are allocated to slot i and subchannel j in the PSSCH slot associated with the PSFCH slot, where M PSFCH subch,slot = M PSFCH PRB , set ⁄ (N subch ·N PSFCH PSSCH ), 0 ≤ i < N PSFCH PSSCH , 0 ≤ j < N subch , and the allocation starts in ascending order of i and continues in ascending order of j. The UE expects M PSFCH PRB,set YesN subch ·N PSFCH PSSCH multiples of.

[0186] The UE determines the number of PSFCH resources available for multiplexing HARQ-ACK information in PSFCH transmission as R PSFCH PRB,CS = N PSFCH type ·M PSFCH subch,slot ·N PSFCH CS , where N PSFCH CS is the number of cyclic shift pairs used for the resource pool, and based on higher layer instructions,

[0187] -N PSFCH type =1 and M PSFCH subch,slot PRBs are associated with the starting subchannel of the corresponding PSSCH

[0188] -N PSFCH type = N PSSCH subch And N PSSCH subch·M PSFCH subch,slot PRBs and corresponding PSSCH N PSSCH subch One or more sub-channels are associated

[0189] PSFCH resources are first based on N PSFCH type ·M PSFCH subch,slot The PRB indices in the N PRBs are indexed in ascending order, and then PSFCH CS The cyclic shift pairs are indexed in ascending order of the cyclic shift pair indices.

[0190] The UE determines the index of the PSFCH resource for PSFCH transmission in response to PSSCH reception as (P ID +M ID ) mod R PSFCH PRB,CS , where P ID is the physical layer source ID provided by SCI format 2-A or 2-B for scheduling PSSCH reception, and M ID M is the identity of the UE receiving the PSSCH indicated by the higher layer if the UE detects SCI format 2-A with the broadcast type indicator field value of "01"; otherwise M ID is zero.

[0191] The UE uses Table 8 to obtain the cyclic shift pair index corresponding to the PSFCH resource index and N PSFCH CS The value of m0 used to calculate the value of the cyclic shift α is determined.

[0192] [Table 8]

[0193]

[0194] In the case where the UE detects SCI format 2-A with a broadcast type indicator field value of "01" or "10" as in Table 9, or in the case where the UE detects SCI format 2-B or SCI format 2-A with a broadcast type indicator field value of "11" as in Table 10, the UE determines m for calculating the value of the cyclic shift α. cs The UE applies one of the cyclic shifts in the cyclic shift pair to the sequence used for PSFCH transmission.

[0195] [Table 9]

[0196] HARQ-ACK value 0 (NACK) 1 (ACK) Sequential cyclic shift 0 6

[0197] [Table 10]

[0198] HARQ-ACK value 0 (NACK) 1 (ACK) Sequential cyclic shift 0 N / A

[0199] At the same time, non-contiguous RBs (equidistant) in frequency may be allocated to the UE. This set of non-contiguous RBs may be referred to as interleaved RBs. This may be useful in a spectrum (e.g., shared spectrum) subject to regulations such as occupied channel bandwidth (OCB), power spectral density (PSD).

[0200] Fig.10 Interleaved RBs based on an embodiment of the present disclosure are shown. Fig.10 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0201] refer to Fig.10 , an interlace of RBs may be defined in the frequency domain. Interlace m∈{0, 1, ..., M-1} may include (common) RBs{m, M+m, 2M+m, 3M+m, ...}, where M may represent the number of RBs of the interlace as given in Table 11.

[0202] [Table 11]

[0203] u M 0 10 1 5

[0204] A communication device (eg, a device, UE, vehicle, drone, etc., as proposed in various embodiments of the present disclosure) may transmit a signal / channel by using one or more interlaced RBs.

[0205] Meanwhile, in the next generation system, the UE may perform a sidelink transmission operation and / or a sidelink reception operation in an unlicensed band. Meanwhile, for the operation in the unlicensed band, depending on the band-specific regulations or requirements, a channel sensing operation (e.g., energy detection / measurement) for the channel to be used may be performed before the UE performs the transmission. The UE may perform the transmission in the unlicensed band only when it is determined that the channel or RB set to be used is idle as a result of the channel sensing (e.g., if the measured energy is less than or equal to a specific threshold). If it is determined that the channel or RB set to be used is busy as a result of the channel sensing (e.g., if the measured energy is greater than or equal to a specific threshold), the UE may cancel all or part of the transmission in the unlicensed band. Meanwhile, in the operation of the unlicensed band, the UE may skip or simplify the channel sensing operation (making the channel sensing interval relatively small) within a specific time after the transmission within a specific time duration. On the other hand, after a specific time has elapsed after the transmission, the UE may determine whether to transmit after performing a conventional channel sensing operation. Meanwhile, for transmission in the unlicensed band, depending on regulations or requirements, the power spectral density (PSD) and / or the size and / or time interval of the frequency occupied domain of the signal / channel sent by the UE may be greater than or equal to a specific level, respectively. Meanwhile, in the unlicensed band, in order to simplify channel sensing, the channel obtained based on the initial general channel sensing may be notified by the channel occupancy time (COT) duration information that the channel is occupied within a specific time, and the maximum length of the COT duration may be configured differently depending on the priority value of the data packet or service.

[0206] At the same time, the base station can share the COT duration event obtained by channel sensing through DCI transmission, and the UE can perform a specific (indicated) channel sensing type and / or CP extension within the COT duration based on the DCI information received from the base station. At the same time, the UE can share the COT duration obtained based on channel sensing with the base station that is the destination of the UE's UL transmission, and can provide relevant information through the UL based on the configured grant uplink control information (CG-UCI). In the above situation, the base station can perform simplified channel sensing within the COT duration shared by the UE. At the same time, in the case of sidelink communication, there is a situation where the UE receives information about the resources to be used for sidelink transmission from the base station through DCI or RRC signaling, such as mode 1 resource allocation (RA) operation, and there is a situation where the UE performs sidelink transmission and reception based on inter-UE sensing operations without the assistance of the base station, such as mode 2 RA operation.

[0207] Meanwhile, in case of channel access type 1, which can be used regardless of the channel occupation time (COT) configuration, DL transmission can be performed based on the procedures shown in Tables 12 to 13.

[0208] [Table 12]

[0209]

[0210]

[0211] [Table 13]

[0212]

[0213]

[0214] Meanwhile, for channel access type 1 which can be used regardless of the channel occupancy time (COT) configuration, UL transmission may be performed based on the procedures shown in Tables 14 to 15.

[0215] [Table 14]

[0216]

[0217] [Table 15]

[0218]

[0219]

[0220] Meanwhile, channel access type 2, which is a simplified channel access type, may be used within a channel occupation time (COT) before transmission, and DL transmission may be performed based on the procedure shown in Table 16.

[0221] [Table 16]

[0222]

[0223]

[0224] Meanwhile, channel access type 2, which is a simplified channel access type, may be used within a channel occupation time (COT) before transmission, and UL transmission may be performed based on the procedure shown in Table 17.

[0225] [Table 17]

[0226]

[0227] In an embodiment of the present disclosure, type 2A SL channel access may be performed in the same manner as type 2A DL and / or UL channel access. For example, type 2A SL channel access may be performed within a sensing interval T_short_sl=25us, where the interval may consist of a duration T_f=16us immediately following a sensing slot, and T_f may include a sensing slot at the beginning of T_f. The basic idle determination in type 2A SL channel access may also borrow idle determination from DL or UL channel access.

[0228] In an embodiment of the present disclosure, type 2B SL channel access may be performed in the same manner as type 2B DL ​​and / or UL channel access. For example, in the case of type 2B SL channel access, the UE may perform transmission immediately after sensing that the channel is idle for a duration of T_f = 16us. T_f may include sensing slots occurring within the last 9us of T_f. The basic idle determination in type 2B SL channel access may also borrow idle determination from DL or UL channel access.

[0229] In an embodiment of the present disclosure, type 2C SL channel access may be performed in the same manner as type 2C DL and / or UL channel access. For example, in the case of type 2C SL channel access, the UE may not perform channel sensing. Alternatively, the time duration of SL transmission may be up to 584us.

[0230] In an embodiment of the present disclosure, type 1 SL channel access may be performed in the same manner as type 1 DL and / or UL channel access. For example, the UE may randomly derive an integer value N based on a contention window size corresponding to a priority class. Then, if the channel sensing result within the delay duration T_d corresponding to the priority class is idle, the UE reduces the N-1 counter value by T_sl when idle. If the counter value is zero, the UE may occupy the RB set or the channel undergoing channel sensing. If it is determined that a portion of the channel sensing results within the T_sl duration are busy, the UE may maintain the counter value until the channel sensing results within the delay duration T_d are idle, and the UE may continue to perform channel sensing. In the above, the delay duration T_d may be composed of T_f=16us and m_p*T_sl consecutively after T_f=16us, where m_p may be a value determined by the priority (p), and T_sl=9us may be a time interval for performing channel sensing.

[0231] Hereinafter, a channel access priority class (CAPC) will be described.

[0232] The CAPC of the MAC CE and radio bearers can be fixed or configured to operate in FR1:

[0233] - Fixed to the lowest priority for filling the Buffer Status Report (BSR) and the Bit Rate Recommendation MAC CE;

[0234] - For SRB0, SRB1, SRB3 and other MAC CEs, they are fixed to the highest priority;

[0235] - Configured by the base station for SRB2 and DRB.

[0236] When selecting the CAPC for a DRB, the base station considers fairness between other service types and transmissions while considering the 5QI of all QoS flows multiplexed to the corresponding DRB. Table 10 shows which CAPC should be used for a standardized 5QI, i.e., the CAPC for a given QoS flow. For a standardized 5QI, the CAPC is defined as shown in the following table, and for a non-standardized 5QI, the CAPC with the best QoS characteristics should be used.

[0237] [Table 18]

[0238]

[0239] Table 19 shows m p , minimum contention window (CW), maximum CW, maximum channel occupancy time (MCOT), and allowed CW size vary in DL depending on the channel access priority class.

[0240] [Table 19]

[0241] Channel access priority class (p) <![CDATA[m p ]]> <![CDATA[CW min,p ]]> <![CDATA[CW max,p ]]> <![CDATA[T mcot,p ]]> <![CDATA[Allowed CW p Size]]> 1 1 3 7 2ms {3,7} 2 1 7 15 3ms {7,15} 3 3 15 63 8 or 10 ms {15,31,63} 4 7 15 1023 8 or 10ms {15,31,63,127,255,511,1023}

[0242] Referring to Table 19, the contention window size (CWS), maximum COT value, etc. for each CAPC may be defined. For example, T d Can be equal to T f + m p * T sl (T d = T f + m p * T sl ).

[0243] Table 20 shows that in UL, mp, minimum contention window (CW), maximum CW, maximum channel occupancy time (MCOT), and allowed CW size vary depending on the channel access priority class.

[0244] [Table 20]

[0245] Channel access priority class (p) <![CDATA[m p ]]> <![CDATA[CW min,p ]]> <![CDATA[CW max,p ]]> <![CDATA[T ulmcot,p ]]> <![CDATA[Allowed CW p Size]]> 1 2 3 7 2 ms {3,7} 2 2 7 15 4 ms {7,15} 3 3 15 1023 6 or 10 ms {15,31,63,127,255,511,1023} 4 7 15 1023 6 or 10 ms {15,31,63,127,255,511,1023}

[0246] Referring to Table 20, the contention window size (CWS), maximum COT value, etc. of each CAPC can be defined. For example, T d Can be equal to T f +m p *T sl (T d =T f +m p *T sl ).

[0247] In an embodiment of the present disclosure, when the UE has occupied a channel through a type 1 SL channel access, the UE may not be ready to send a sidelink transmission. In this case, the UE may configure a delay duration of length T_d and a sensing duration of length T_sl just before the sidelink transmission that it is ready to send. Here, if both are idle, the UE may perform the sidelink transmission immediately, but if at least one of the delay duration and the sensing duration is busy, the UE may perform a type 1 SL channel access again. For example, if the sidelink transmission cannot be performed at the end of the channel sensing (for example, if the end of the channel sensing is after the start of the sidelink transmission), the UE may reselect the sidelink transmission resources.

[0248] Meanwhile, when performing transmission on a shared spectrum band, the wireless device may send a cyclic prefix extension (CPE) before (or together with) the transmission to achieve alignment of orthogonal frequency division multiplexing (OFDM) symbols and reduce inter-symbol interference (ISI). In addition, the UE may perform CPE transmission to increase the probability that a channel on which LBT has been successfully performed can be used for actual transmission. For example, if the UE succeeds in LBT on a specific channel, the UE may perform CPE transmission to prevent other devices from occupying the specific channel.

[0249] At the same time, if two transmissions that start transmission at the same time cannot recognize each other's transmission, a conflict may occur because the channel sensing results are determined to be idle for each other. At the same time, if the start time is randomly adjusted by CP extension and / or puncturing of a single start symbol or multiple start symbols, some channels may be determined to be busy when channel sensing is performed for each transmission. This may lead to the problem of not being able to support FDM between different resources within the same RB set. At the same time, in the case of sidelink mode 2 resource (re)selection, the problem of overlapping transmission resources for different transmissions is avoided or alleviated by the reserved resources indicated in the previous transmission.

[0250] For example, when performing sidelink transmission (e.g., PSCCH / PSSCH transmission and / or PSFCH transmission and / or S-SSB transmission), the UE may adjust the starting position of the actual sidelink channel / signal transmission by extending the CP and / or puncturing one or more starting symbols starting from the first symbol, and the length of the CP extension and / or the length of the puncturing may be randomly selected from specific (pre)configured candidates and / or predefined candidates. For example, the random adjustment of the starting position of the actual sidelink channel / signal transmission may be used only when the sidelink channel / signal uses all frequency resources within the RB set, and / or the number of allocated RBs is greater than or equal to a (pre)configured or predefined value, and / or the number of allocated RBs relative to the total number of RBs within the RB set is greater than or equal to a (pre)configured or predefined value, and / or the sidelink channel / signal transmission is an initial transmission and / or resource reservation of the sidelink channel / signal has not been previously indicated. The fundamental reason for this is that, in the case of initial transmission, the collision between different transmissions may not be avoided by the sidelink reserved resource indication method.

[0251] For example, a UE operation for adjusting the starting position of an actual sidelink channel / signal transmission by using an extension starting from the first symbol CP and / or one or more start symbols when performing a sidelink transmission (e.g., PSCCH / PSSCH transmission and / or PSFCH transmission and / or S-SSB transmission) may be used only when the number of allocated RBs is greater than or equal to a (pre)configured or predefined value, and / or the number of allocated RBs relative to the total number of RBs in the RB set is greater than or equal to a (pre)configured or predefined value, and / or the sidelink channel / signal transmission is an initial transmission and / or resource reservation for which a sidelink channel / signal has not been previously indicated may be used. For example, if the resource pool is configured as a single RB set, a UE operation for adjusting the starting position of an actual sidelink channel / signal transmission by using an extension starting from the first symbol CP and / or one or more start symbols when performing a sidelink transmission (e.g., PSCCH / PSSCH transmission and / or PSFCH transmission and / or S-SSB transmission) may be used. For example, if the resources selected for the sidelink channel / signal transmission are not FDMed with the reserved resources of another UE derived based on the SCI or UE-to-UE coordination information received by the UE, a UE operation for adjusting the starting position of the actual sidelink channel / signal transmission using a CP extension starting from the first symbol and / or one or more starting symbols when performing sidelink transmission (e.g., PSCCH / PSSCH transmission and / or PSFCH transmission and / or S-SSB transmission) may be used. For example, the case where the resources are not FDMed may be a case where the reserved resources of another UE derived based on the SCI or UE-to-UE coordination information received by the UE are not in the same time slot and / or the same RB set. For example, when performing resource (re)selection for sidelink channel / signal transmission with multiple (pre)configured starting positions, if the transmission resources are selected in the form of FDMed with the reserved resources of another UE and / or if the transmission resources are selected in the form of existing in the same time slot and / or the same RB set as the reserved resources of another UE, the UE may perform the sidelink channel / signal transmission based on a (pre)configured single CP extension (length) and / or a single starting symbol position. For example, when performing resource (re)selection for sidelink channel / signal transmission having multiple (pre-)configured starting positions, if the transmission resources are selected in a form of being FDMed with reserved resources of another UE and / or in a form of being present in the same time slot and / or the same RB set as the reserved resources of another UE, the UE can perform sidelink channel / signal transmission by inheriting the CP extension (length) and / or starting symbol position of the reserved resources of another UE that is FDMed.For example, the CP extension (length) and / or the starting symbol position of the reserved resources may be indicated in the first SCI and / or the second SCI and / or the PSSCH indicating the reserved resources, and / or may be (pre)configured. For example, when performing resource (re)selection for sidelink channel / signal transmission with multiple (pre)configured starting positions, if the transmission resources are selected in the form of FDM with the reserved resources of another UE and / or in the form of existing in the same time slot and / or the same RB set as the reserved resources of another UE, the UE may perform resource (re)selection by avoiding FDM with the reserved resources of another UE or by avoiding resources in the corresponding time slot and / or RB set.

[0252] In an embodiment of the present disclosure, based on the RSRP measurement value of the reserved resource and / or the representative SL reception priority value or CAPC value of the reserved resource and / or the representative SL transmission priority value or CAPC value of the side link channel / signal transmission of the UE and / or the congestion control level and / or the channel occupancy rate (CR) / channel busy rate (CBR), etc., the UE can determine whether to perform FDM on the side link channel / signal transmission and the reserved resources of another UE derived based on the reception of SCI or UE-to-UE coordination information, and / or whether there are reserved resources of another UE in the same time slot and / or the same RB set. For example, regardless of the RSRP measurement value and / or the SL transmission priority value and / or the SL reception priority value of the reserved resource, the UE can determine whether to perform FDM on the side link channel / signal transmission and the reserved resources of another UE derived based on the reception of SCI and / or whether there are reserved resources of another UE in the same time slot and / or the same RB set. The above scheme may be useful in protecting the reserved resources of another UE that performs FDM. For example, if the RSRP measurement value of the reserved resources is greater than or equal to the first threshold, and / or if the RSRP measurement value of the reserved resources is less than or equal to the second threshold, and / or the SL transmission priority value is greater than and / or equal to the SL reception priority value of the reserved resources, and / or the SL reception priority value of the reserved resources is less than or equal to the second threshold, the UE can determine the reserved resources FDM of the other UE derived from the opposite link channel / signal transmission and SCI reception, and / or can determine that there are reserved resources of another UE in the same time slot and / or the same RB set. For example, the first threshold can be a (pre) configured value for each resource pool and / or each SL transmission priority and / or each SL reception priority and / or each congestion control level and / or a value derived from these values ​​(by boosting, etc.). For example, the second threshold can be a (pre) configured value for each resource pool and / or each congestion control level. For example, if the RSRP measurement value of the reserved resources is less than or equal to a first threshold, and / or if the RSRP measurement value is greater than or equal to a second threshold, and / or if the SL transmission priority value is less than or equal to the SL reception priority value of the reserved resources, and / or if the SL transmission priority value is less than or equal to the second threshold, the UE may not determine the reserved resources FDM of the opposite link channel / signal transmission and another UE derived based on SCI reception, and / or may not determine the existence of reserved resources of another UE in the same time slot and / or the same RB set, or may ignore the reserved resources of another UE.

[0253] Table 21 shows an example of SL received signal strength indicator (RSSI).

[0254] [Table 21]

[0255] definition The Sidelink Received Signal Strength Indicator (SL RSSI) is defined as the linear average of the total received power (in [W]) observed in the configured subchannels in the OFDM symbols of the slot configured for PSCCH and PSSCH, starting from the 2nd OFDM symbol. For frequency range 1, the reference point for the SL RSSI shall be the antenna connector of the UE. For frequency range 2, the SL RSSI shall be measured based on the combined signals of the antenna elements corresponding to a given receiver branch. For frequency ranges 1 and 2, if the UE uses receiver diversity, the reported SLRSSI value shall not be lower than the corresponding SL RSSI of any of the individual receiver branches. Applies to In RRC_IDLE frequency, between RRC_IDLE frequencies, in RRC_CONNECTED frequency, between RRC_CONNECTED frequencies

[0256] Table 22 shows an example of SL channel occupancy rate (CR).

[0257] [Table 22]

[0258] definition The sidelink channel occupancy rate (SL CR) evaluated at time slot n is defined as the total number of subchannels used for transmission in time slot [na, n-1] and granted in time slot [n, n +b] divided by the total number of configured subchannels in the transmission pool over [na, n+b]. Applies to In RRC_IDLE frequency, between RRC_IDLE frequencies, in RRC_CONNECTED frequency, between RRC_CONNECTED frequencies

[0259] NOTE 1: a is a positive integer and b is 0 or a positive integer; a and b utilize a+b+1 = 1000 or 1000·2u time slots, b < (a+b+1) / 2 is determined by the UE implementation according to the higher layer parameter sl-TimeWindowSizeCR, and n+b shall not exceed the last transmission opportunity granted for the current transmission.

[0260] Note 2: SL CR is evaluated for each (re)transmission.

[0261] NOTE 3: When evaluating the SL CR, the UE shall assume that the transmission parameters used at slot n according to the existing grants in slots [n+1, n+b] are reused in the absence of packet loss.

[0262] Note 4: The slot index is based on the physical slot index.

[0263] Note 5: SL CR can be calculated for each priority level

[0264] Note 6: A resource is considered licensed if it is a member of the selected sidelink license.

[0265] Table 23 shows an example of SL channel busy rate (CBR).

[0266] [Table 23]

[0267] definition <![CDATA[The SL Channel Busy Ratio (SL CBR) measured in time slot n, according to the higher layer parameter sl-TimeWindowSizeCBR, is defined as the fraction of subchannels in the resource pool where the SL RSSI measured by the UE exceeds the (pre)-configured threshold sensed over the CBR measurement window [n-a, n-1], where a is equal to 100 or 100·2 µ time slots. When the UE is configured for partial sensing by the higher layer (including when configuring SL DRX), the SL RSSI is measured in the time slots where the UE performs partial sensing and the UE performs PSCCH / PSSCH reception within the CBR measurement window. The calculation of the SL CBR is limited to the time slots where the SL RSSI is measured. If the number of SL RSSI measurement time slots within the CBR measurement window is lower than the (pre)-configured threshold, the (pre)-configured SL CBR value is used.]]> Applies to In RRC_IDLE frequency, between RRC_IDLE frequencies, in RRC_CONNECTED frequency, between RRC_CONNECTED frequencies

[0268] Note 1: The slot index is based on the physical slot index.

[0269] For example, in the case of symbol puncturing, the presence or absence of puncturing and / or the possible time interval length may be different based on the subcarrier spacing (SCS) used for sidelink communication. For example, in the case of 15kHz and / or 30kHz SCS, puncturing of a portion of the symbol time interval may be allowed, and in the case of 30kHz and / or 60kHz and / or 120kHz, puncturing may not be allowed.

[0270] Meanwhile, in the case of sidelink communication on a shared spectrum, a problem of increased latency may occur due to channel sensing failure.

[0271] Fig.11The problem of increased delay time due to channel sensing failure is shown. Fig.11 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0272] refer to Fig.11 , a UE that has selected / reserved resources on time slot #1 may perform LBT before performing SL transmission on the shared spectrum. If the UE fails LBT, the UE may not be allowed to perform SL transmission using the resources selected / reserved on time slot #1. In this case, because time slots #2 to #7 are time slots where SL communication is not allowed (e.g., time slots that do not belong to the resource pool), the LBT failure may cause severe delays in SL communication. In particular, if time slots where SL communication is not allowed (e.g., time slots that do not belong to the resource pool) are configured continuously, the above problem may become more serious.

[0273] Therefore, in order to alleviate the problem of increased delay time due to channel sensing failure, different starting symbol positions or different starting time positions within a time slot may be allowed for sidelink communication, especially PSCCH / PSSCH transmission.

[0274] Fig.12 Multiple starting symbol positions or multiple starting time positions within a time slot according to an embodiment of the present disclosure are shown. Fig.12 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0275] refer to Fig.12 , the starting symbol position within the time slot can be configured as symbol #A and symbol #B. In this case, for example, the UE can perform SL transmission using symbol #A to the last symbol within the time slot, or the UE can perform SL transmission using symbol #B to the last symbol within the time slot.

[0276] For example, if the UE transmits PSCCH / PSSCH from an additionally allowed starting position, the PSCCH / PSSCH transmission signal may be transmitted in a delayed form depending on the starting position. For example, compared to when the transmission of PSCCH / PSSCH starts from the basic starting position, the transmission interval length of PSCCH / PSSCH may be reduced, and the second half of the time domain of the PSCCH / PSSCH transmission signal may be punctured.

[0277] For example, in this case, in the case of a PSCCH demodulation reference signal (DMRS) and / or a PSSCH DMRS and / or a CSI-RS sequence, a sequence generated based on a case where no transmission delay is performed and starting from a basic starting position (i.e., a sequence generated based on a symbol index to which the RS is mapped in the above case) may be mapped to a symbol index that changes according to the transmission delay. For example, the symbol index of the RS actually transmitted and the symbol index used to generate the RS sequence may be different.

[0278] For example, in this case, the PSCCH DMRS and / or PSSCH DMRS and / or CSI-RS sequence may be changed according to the transmission delay to a sequence generated based on a symbol index in which actual transmission occurs.

[0279] In the embodiments of the present disclosure, it can be processed in different ways depending on the RS type. For example, the PSCCH DMRS can use a sequence based on a reference before the transmission delay, while the PSSCH DMRS can use a sequence changed based on a reference after the transmission delay.

[0280] For example, when the UE transmits PSCCH / PSSCH from an additionally allowed starting position, a portion of the PSCCH / PSSCH transmission signal (symbols before the starting position) may be punctured depending on the starting position. At the same time, decoding of the first SCI and / or the second SCI may be impossible or inefficient due to the puncturing, and in this case, even if the PSCCH / PSSCH is transmitted by changing the starting position, the receiving UE cannot correctly decode the PSCCH / PSSCH.

[0281] For example, the UE may repeatedly transmit the PSCCH starting from an otherwise allowed starting position. For example, a set of symbols for repeatedly mapping the PSCCH may be determined so as not to overlap with a specific PSSCH DMRS symbol candidate. For example, a specific PSSCH DMRS symbol candidate may include DMRS symbols of all PSSCH DMRS patterns supported by the NR SL. For example, a specific PSSCH DMRS symbol candidate may include DMRS symbols of all PSSCH DMRS patterns configured in a resource pool for PSCCH / PSSCH transmission. For example, a symbol group of a specific PSSCH DMRS pattern may be excluded from the avoidance target. A specific PSSCH DMRS pattern may have 2 symbols, in which case puncturing for PSCCH / PSSCH signals may not be allowed. For example, the number of symbols repeated by the PSCCH may be the number of symbols (pre) configured for PSCCH transmission excluding AGC symbols. For example, the number of symbols repeated for the PSCCH may include the number of AGC symbols in addition to the number of symbols (pre) configured for PSCCH transmission. For example, the number of symbols used for PSCCH transmission can be significantly increased, and the position where the PSCCH / PSSCH is allowed to start can be (pre-)configured within the PSCCH symbol duration. For example, the starting symbol position for the PSCCH can be changed to be located in the middle of the symbol duration of the PSSCH. For example, in this case, the AGC symbol used for the PSCCH / PSSCH can be in the form of copying the first symbol of the PSSCH, or can be in the form of copying the PSCCH / PSSCH symbol including the first symbol of the PSCCH. For example, the starting position of the PSCCH can be (pre-)configured per resource pool. For example, the symbol group to which the PSCCH with a changed starting position is mapped can be determined so as not to overlap with the PSSCH DMRS symbol candidates. Table 24 shows an example of the PSSCH DM-RS time domain position in the NR SL.

[0282] [Table 24]

[0283]

[0284] According to Table 24, the position of the DM-RS symbol is given by l, where the number of PSSCH DM-RS is indicated in the SCI, and l d is the duration of the scheduled resources used to transmit the PSSCH and the associated PSCCH, including repeated OFDM symbols.

[0285] For example, the UE may repeatedly map the second SCI starting from an additionally allowed starting position. For example, when mapping the second SCI, an upper limit on the amount of resources to which the second SCI is mapped may be determined only before the next starting position. For example, a beta scaling value (e.g., a beta_offset indicator) for determining the number of REs to which the second SCI is mapped may be indicated by each repetition of the first SCI for the second SCI. For example, the UE may increase the number of REs for the second SCI, and the starting position of the PSCCH / PSSCH may be within the symbol duration to which the second SCI is mapped. For example, alternatively, the symbol duration to which the second SCI is mapped may be determined to include all or part of the starting allowed position candidates for the PSCCH / PSSCH. For example, an increase in the number of REs mapped by the second SCI may mean an increase in the beta value mapped by the second SCI. Alternatively, for example, a scaling value may be additionally multiplied when deriving the number of REs mapped by the second SCI, and the scaling value may be (pre) configured and / or indicated separately from the beta in the first SCI. For example, the position of the symbol at which the second SCI mapping starts can be changed to a time later than the immediately following symbol of the first PSSCH DMRS symbol. For example, the starting symbol position for the second SCI mapping can be determined after a specific symbol offset relative to the first symbol position of the PSCCH / PSSCH (including or excluding AGC), or relative to the first symbol of the time slot, or relative to the first PSSCH DMRS transmission symbol (or immediately following symbol). For example, a specific symbol offset can be (pre)configured and / or indicated in the first SCI. For example, the starting symbol position for the second SCI mapping can be changed to the next symbol of the second PSSCH transmission symbol. For example, the starting symbol position for the second SCI mapping can be changed to the latest symbol among the additional allowed starting positions for PSCCH / PSSCH. For example, if the PSSCH DMRS is sent at the changed symbol position, the second SCI can be mapped from the next symbol of the DMRS symbol.

[0286] For example, if multiple starting (symbol) positions are allowed for PSCCH / PSSCH transmission in a time slot (for example, if multiple starting symbol positions are (pre)configured in a resource pool), when the UE sends PSCCH / PSSCH based on a first starting symbol position, the UE may repeat the transmission of the contents of REs mapped to other symbol positions in a specific case for REs corresponding to a second starting symbol position. For example, the other symbol positions to be replicated may be (pre)configured and / or may be the first symbol position of the PSCCH / PSSCH transmission based on the first starting symbol position and / or may be symbol positions before or after the second starting symbol position. For example, the specific situation may be that the second starting symbol position for PSCCH / PSSCH transmission based on the first starting symbol position is not a PSSCH DMRS symbol, and / or the number of code blocks (CBs) is greater than or equal to a specific level (e.g., a predefined or (pre) configured threshold), and / or the MCS value is greater than or equal to a specific level (e.g., a predefined or (pre) configured threshold), and / or the TB size is greater than or equal to a specific level (e.g., a predefined or (pre) configured threshold), and / or the number of RB sets included in the resource pool is a plural number or is greater than or equal to a specific level (e.g., a predefined or (pre) configured threshold).

[0287] In an embodiment of the present disclosure, the possibility of PSCCH / PSSCH transmission in an additional starting position may be applied differently depending on the number of PSSCH DMRS patterns or DMRS symbols, and / or depending on the channel access type used for side link transmission, and / or depending on the SL priority value, and / or depending on the CAPC. For example, if the number of remaining PSSCH DMRS symbols is zero or 1 due to a change in the starting position, the change in the starting position may not be allowed.

[0288] In an embodiment of the present disclosure, adjusting the starting position of the actual side link channel / signal transmission according to the channel sensing result can be used only when the side link channel / signal uses all frequency resources in the RB set and / or the number of allocated RBs is greater than or equal to a (pre) configured value or a predefined value, and / or the number of allocated RBs relative to the total number of RBs in the RB set is greater than or equal to a (pre) configured value or a predefined value, and / or the side link channel / signal transmission is an initial transmission and / or resource reservation for which the side link channel / signal was not previously indicated and / or the side link channel / signal transmission is a retransmission.

[0289] Meanwhile, even in the case of sending TB transmission through PSSCH, if the number of CBs is large, the entire coded bits of a specific CB may be punctured due to the change in the starting position. In this case, if CBG-based transmission is not performed, partial transmission due to the change in the starting position may not be suitable in terms of TB decoding performance.

[0290] For example, the UE may first map the PSSCH to the time domain in the unlicensed band, and then map it to the frequency domain. For example, when mapping the modulation symbols for the coding of the second SCI and / or TB, the UE may start from the subcarrier with the lowest index and perform RE mapping in ascending order from the lowest symbol index. After increasing the symbol index, the UE may perform RE mapping on the next subcarrier again in ascending order from the lowest symbol index. The UE may then repeat the above process. For example, mapping of the PSCCH may be performed in the order of symbol group index, frequency domain index, and symbol index within the symbol group. For example, different symbol durations may be specified in multiples based on the symbol in which the start of the PSCCH / PSSCH is allowed, and / or may be divided into time intervals in which the PSCCH / PSSCH can be punctured and other time intervals.

[0291] For example, the UE may divide each CB into two or more parts and perform mapping from different starting symbol indices. For example, different symbol durations may be specified in multiples based on the symbol at which the PSCCH / PSSCH is allowed to start, and / or may be divided into time intervals capable of puncturing the PSCCH / PSSCH and other time intervals. For example, a portion of the CB to be mapped to the puncturing capable portion may correspond to a parity bit.

[0292] For example, the UE may change the order of CBs to be mapped starting from the starting symbol differently for each transmission. For example, the offset of the starting CB index to be mapped first above may be indicated in the first SCI and / or the second SCI, and / or may be determined based on the time slot index in which the PSCCH / PSSCH is transmitted.

[0293] For example, the UE may generate and map a PSCCH / PSSCH signal based on the latest symbol index among the symbol indexes that allow the PSCCH / PSSCH to start, and the UE may copy and fill part of the symbols used for the generated PSCCH / PSSCH into the remaining PSCCH / PSSCH resources. For example, the symbol group to be copied may be selected from the first symbol of the generated PSCCH / PSSCH.

[0294] At the same time, even if multiple starting (symbol) positions are allowed for PSCCH / PSSCH transmission, the receiving UE may need to derive the reserved resources and RSRP measurement values ​​of another UE from the received SCI based on different starting symbol positions. For example, based on the symbol starting position where the UE receives PSCCH / PSSCH, the symbol starting position of the reserved resources indicated in PSCCH / PSSCH can be configured identically. For example, if the UE receives PSCCH / PSSCH at the first starting symbol or the second starting symbol, the symbol starting position for the reserved resources indicated by PSCCH / PSSCH can be the first starting symbol position or the second starting symbol position, respectively. For example, whether to exclude resources can be applied differently depending on the symbol position of the reserved resources. For example, when sending PSCCH / PSSCH, the UE can indicate the starting symbol position of the reserved resources for all reserved resources and / or each reserved resource indicated by PSCCH / PSSCH through PSCCH and / or PSSCH. For example, if the UE receives the PSCCH / PSSCH at the first starting symbol or the second starting symbol, the symbol starting position indicated by the PSCCH / PSSCH for the reserved resources may be fixed to the first starting symbol position (e.g., a symbol position earlier in time). For example, the UE may utilize the PSCCH detected in different symbols and / or different RB sets in the same time slot for resource (re)selection during a sensing operation.

[0295] For example, depending on the starting symbol position of PSCCH / PSSCH, the reference signal type for RSRP measurement may be different. For example, each starting symbol position for PSCCH / PSSCH may be (pre-)configured whether RSRP measurement is based on PSCCH DMRS or RSRP measurement is based on PSSCH DMRS.

[0296] Meanwhile, the UE may expect to receive the PSFCH for the SLHARQ-ACK for the TB transmitted through the PSSCH after the PSCCH / PSSCH transmission, and the receiving UE may not be able to transmit the PSFCH depending on the channel sensing result.

[0297] For example, as part of a method to mitigate frequent PSFCH transmission failures, simplified channel sensing may be performed on PSFCH transmissions. For example, a transmitting UE may perform PSCCH / PSSCH transmissions with SL HARQ-ACK feedback enabled, such that the number of PSFCH transmissions within a specific time interval (e.g., 50ms or a (pre)configured value) is less than or equal to a specific level (e.g., 50 or a (pre)configured value) and / or such that the sum of the transmission interval lengths of the PSFCH to be transmitted within a specific time interval (e.g., 50ms or a (pre)configured value) is less than and / or equal to a specific level (e.g., 2500us or a (pre)configured value). For example, scheduling restrictions may be performed per receiving UE and / or per destination ID. For example, in this case, the receiving UE may perform simplified channel sensing (e.g., type 2A or type 2B or type 2C) on PSFCH transmissions.

[0298] For example, if the number of PSFCH transmissions within a specific time interval (e.g., 50ms or a (pre)configured value) exceeds 50, and / or if the sum of the transmission interval lengths of the PSFCH to be transmitted within a specific time interval (e.g., 50ms or a (pre)configured value) is greater than and / or equal to a specific level (e.g., 2500us or a (pre)configured value), the PSCCH / PSSCH receiving UE may omit the PSFCH transmission, and / or perform channel sensing on subsequent PSFCH transmissions based on type 1 channel access (until the above conditions are met again). For example, when determining the above conditions, the PSFCH transmitted by performing type 1 channel access may be excluded.

[0299] For example, as part of a method for alleviating the frequent PSFCH transmission failures described above, the number of PSFCH opportunities or time slots associated with PSCCH / PSSCH may be 2 or more. For example, a PSCCH / PSSCH transmitting UE may indicate in the first SCI and / or the second SCI information about whether it is the earliest PSFCH or the next PSFCH after the minimum PSSCH to PSFCH timing, etc. For example, in this case, if another UE determines in mode 2 resource (re)selection that the resources corresponding to PSCCH / PSSCH are excluded from the candidate resources, the UE may exclude the PSFCH resources indicated by PSCCH / PSSCH and / or all PSFCH resources that PSCCH / PSSCH can indicate from the PSFCH candidate resources. In addition, based on this, the UE may select a PSFCH resource from the PSFCH candidate set when indicated again during PSCCH / PSSCH transmission. For example, the association between PSCCH / PSSCH and PSFCH may exist for each of multiple timings. For example, the PSFCH resources for timing settings can be divided in terms of frequency and / or time (symbol index) and / or cyclic shift pairs. For example, in this case, the PSCCH / PSSCH receiving UE can send SL HARQ-ACK feedback in the first associated PSFCH where channel sensing is successful. For example, in this case, the PSCCH / PSSCH sending UE can attempt PSFCH detection for multiple PSFCH time slots, and if there is ACK in the HARQ-ACK state determined for each PSFCH time slot, the PSCCH / PSSCH sending UE can determine the ACK for the TB sent via the PSSCH.

[0300] At the same time, the UE may allow multiple start symbols for PSCCH / PSSCH transmission. In this case, the UE may prepare in advance the generation of PSCCH / PSSCH and related waveforms based on multiple start symbols, and the UE may send PSCCH / PSSCH based on a specific start symbol depending on the time when the channel sensing result is determined to be idle. For example, depending on the symbol in which the start of PSCCH / PSSCH is allowed, all or part of the indication value indicated by the UE in the first SCI and / or the second SCI may be different. For example, in the case of the number of PSSCH DMRS symbols mentioned above, different values ​​may be indicated in the SCI for each symbol in which the start is allowed. The reason for this is that when the start symbol is different, the symbol duration length of the PSSCH may also be different, and therefore, the number of DMRS symbols that can be supported may also be different. For example, in the case of an indicator for the second SCI format and / or a beta offset value indicator and / or a PSFCH overhead indicator used to adjust the number of REs to which the second SCI is mapped, different values ​​may be indicated in the SCI for each symbol that allows the start. The reason for doing this is to adjust the ratio of control information overhead as the symbol duration length of the PSSCH changes.

[0301] Meanwhile, if multiple start symbols for PSCCH / PSSCH transmission are allowed within a time slot, a problem of a transport block size (TBS) change may occur even if the same TB is transmitted. If the TBS changes, the receiving UE may determine TBs with different TBSs as different TBs, and the receiving UE may perform independent decoding on different TBs. In this case, a problem may also occur that HARQ combining cannot be performed because the TBSs are different even if the TBs are the same.

[0302] For example, in the case where multiple start symbols are allowed, the UE can guarantee the same transport block (TB) size for PSCCH / PSSCH transmission. For example, if multiple PSCCH / PSSCH start symbols are allowed, the UE can calculate the TB size based on the number of allocated REs derived from the maximum PSSCH symbol duration length. For example, if multiple PSCCH / PSSCH start symbols are allowed, the UE can calculate the TB size based on the number of allocated REs derived from the minimum PSSCH symbol duration length. For example, if multiple PSCCH / PSSCH start symbols are allowed, the UE can calculate the TB size based on the number of allocated REs derived from the average PSSCH symbol duration length based on the symbols allowed to start. For example, if multiple PSCCH / PSSCH start symbols are allowed, the UE can calculate the TB size based on the number of allocated REs derived from the reference PSSCH symbol duration length (pre) configured for TBS calculation. For example, if multiple PSCCH / PSSCH start symbols are allowed, the UE can calculate the TB size based on the number of allocated REs derived from the reference PSSCH symbol duration length indicated in the first SCI for TBS calculation. For example, if multiple PSCCH / PSSCH start symbols are allowed, the UE may calculate the TB size based on the number of allocated REs derived from the reference PSSCH symbol duration length indicated in the second SCI for TBS calculation. For example, when calculating the TB size, the PSSCH DMRS overhead and / or the number of REs to which the second SCI is mapped may be determined based on the PSSCH symbol duration length used in the TBS calculation. For example, when calculating the TB size, for the number of REs to which the second SCI is mapped and / or the PSSCH DMRS overhead, the maximum value among the values ​​that can be derived from the PSSCH symbol duration length and / or the PSCCH / PSSCH start symbol index may be used. For example, when calculating the TB size, for the number of REs to which the second SCI is mapped and / or the PSSCH DMRS overhead, the minimum value among the values ​​that can be derived from the PSSCH symbol duration length and / or the PSCCH / PSSCH start symbol index may be used. For example, when calculating the TB size, for the number of REs to which the second SCI is mapped and / or the PSSCH DMRS overhead, an average value of values ​​that can be derived according to the PSSCH symbol duration length and / or the PSCCH / PSSCH start symbol index may be used.

[0303] For example, the UE may first determine the number of REs allocated for PSSCH within a PRB (N' RE ). For example, N' RE It can be obtained by Eq. 1.

[0304] [Equation 1]

[0305]

[0306] Here, for example, N RB sc It can be the number of subcarriers in a PRB. For example, N RB SC It can be 12. For example, N sh symb It can be sl-LengthSymbols-2, where sl-LengthSymbols can be the number of sidelink symbols in a slot and can be provided by higher layers. For example, if multiple PSCCH / PSSCH start symbols are allowed, then N sh symb It can be the reference PSSCH symbol duration length (pre-)configured for TBS calculation. For example, if multiple PSCCH / PSSCH start symbols are allowed, sl-LengthSymbols can be the reference PSSCH symbol duration length (pre-)configured for TBS calculation. For example, N PSFCH symb It can be determined by the PSFCH overhead indication of the first SCI and the higher layer parameter sl-PSFCH-Period. For example, if the higher layer parameter sl-PSFCH-Period is 2 or 4, if the "PSFCH Overhead Indicator" field of the first SCI indicates "1", then N PSFCH symb =3, otherwise N PSFCH symb = 0. If the higher layer parameter sl-PSFCH-Period is 0, then N PSFCH symb = 0. If the higher layer parameter sl-PSFCH-Period is 1, then N PSFCH symb =3. For example, N PSFCH symb It can be determined based on the embodiments proposed in this disclosure. For example, N PRB oh It can be the overhead given by the higher layer parameter sl-X-Overhead. For example, N PRB oh It can be determined based on the embodiments proposed in this disclosure. For example, N DRMS RE It may be given by Table 25 according to the higher layer parameter sl-PSSCH-DMRS-TimePatternList. For example, N may be determined based on the embodiments proposed in the present disclosure. DRMSRE .

[0307] [Table 25]

[0308] sl-PSSCH-DMRS-TimePatternList <![CDATA[N DRMS RE ]]> {2} 12 {3} 18 {4} 24 {2,3} 15 {2,4} 18 {3,4} 21

[0309] In addition, the UE can determine the total number of REs allocated for PSSCH (N RE ). For example, N RE It can be obtained by Equation 2.

[0310] [Equation 2]

[0311]

[0312] Here, for example, n PRB It can be the total number of PRBs allocated for PSSCH. SCI,1 RE It can be the total number of REs occupied by PSCCH and PSCCH DM-RS. SCI,2 RE It can be the number of coded modulation symbols generated for the second stage SCI transmission.

[0313] In addition, the UE can obtain the intermediate value of the information bit (N info ). info It can be obtained by Equation 3.

[0314] [Equation 3]

[0315]

[0316] Here, R can be the coding rate, and Q m It can be the modulation order. v can be the number of layers.

[0317] In addition, based on the calculated N info UE can be based on Fig.13 The process shown determines TBS. Fig.13 A process for a UE to determine a transport block size (TBS) according to an embodiment of the present disclosure is shown. Fig.13 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0318] At the same time, if N info Less than or equal to 3824, the UE can determine the TBS based on Table 26.

[0319] [Table 26]

[0320] index TBS index TBS index TBS index TBS 1 24 31 336 61 1288 91 3624 2 32 32 352 62 1320 92 3752 3 40 33 368 63 1352 93 3824 4 48 34 384 64 1416 5 56 35 408 65 1480 6 64 36 432 66 1544 7 72 37 456 67 1608 8 80 38 480 68 1672 9 88 39 504 69 1736 10 96 40 528 70 1800 11 104 41 552 71 1864 12 112 42 576 72 1928 13 120 43 608 73 2024 14 128 44 640 74 2088 15 136 45 672 75 2152 16 144 46 704 76 2216 17 152 47 736 77 2280 18 160 48 768 78 2408 19 168 49 808 79 2472 20 176 50 848 80 2536 21 184 51 888 81 2600 22 192 52 928 82 2664 23 208 53 984 83 2728 24 224 54 1032 84 2792 25 240 55 1064 85 2856 26 256 56 1128 86 2976 27 272 57 1160 87 3104 28 288 58 1192 88 3240 29 304 59 1224 89 3368 30 320 60 1256 90 3496

[0321] For example, the UE may align all PSSCH symbol duration lengths to be the same for the same TB. For example, the UE may align all PSCCH / PSSCH start symbols to be the same for the same TB transmission. For example, the PSSCH symbol duration length may always be the same regardless of the PSCCH / PSSCH start symbol.

[0322] For example, depending on the symbols allowed to start for PSCCH / PSSCH, the UE may keep all indication values ​​of the first SCI and / or second SCI indication the same. For example, in the case of the number of PSSCH DMRS symbols mentioned above, if the PSSCH symbol duration length does not support the number of DMRS symbols indicated according to the PSSCH start symbol, the UE may replace the actual PSSCH symbol duration length with the maximum number of DMRS symbols that can be supported by the PSSCH symbol duration length among those that are less than the number of DMRS symbols indicated. For example, the maximum number of DMRS symbols that can be supported may be limited to be selected from a (pre) configured value in a resource pool. For example, depending on the symbols in which the start is allowed, the upper limit of the number of REs to which the above-mentioned second SCI is mapped may be determined based on the number of allocated REs derived from the maximum PSSCH symbol duration length and / or the minimum PSSCH symbol duration length and / or the average PSSCH symbol duration length. For example, in the case of the above-mentioned PSFCH overhead indicator, if PSFCH resources are not allowed in the PSSCH symbol duration length that changes according to the symbol that allows startup, the UE may ignore the PSFCH overhead indicator even if the PSFCH overhead indicator is set to 1. In this case, the UE may not consider the PSFCH overhead when calculating the TB size and / or when calculating the RE to which the second SCI is mapped, and the PSFCH overhead may be omitted.

[0323] For example, the symbols allowed for the start of PSCCH / PSSCH may be limited according to an indication value indicated by the first SCI and / or the second SCI through the UE. For example, according to the number of PSSCH DMRS symbols indicated by the UE in the above SCI, when sending PSCCH / PSSCH, only the symbols allowed to start corresponding to the PSSCH symbol duration that can support the indicated number of DMRS symbols may be considered / applied. For example, according to the PSFCH overhead value indicated by the UE in the above SCI, when sending PSCCH / PSSCH, only the symbols allowed to start corresponding to the PSSCH symbol duration that can support the indicated PSFCH overhead value may be considered / applied.

[0324] In an embodiment of the present disclosure, the UE may perform different channel sensing on the starting symbol / position for PSCCH / PSSCH in a time slot. For example, the UE may apply different energy detection thresholds to each starting symbol / position. For example, the UE may set the energy detection threshold for the second starting symbol / position to be lower than the energy detection threshold for the first starting symbol / position. The reason for doing this is to minimize the surrounding impact caused by using the second starting symbol / position. For example, the UE may set the energy detection threshold for the second starting symbol / position to be higher than the energy detection threshold for the first starting symbol / position. The reason for doing this is to increase the possibility of channel access at the second starting symbol / position after the LBT of the first starting symbol / position fails. For example, only when the PSSCH transmission is the initial transmission, the channel access attempt at the second starting symbol / position can be performed after the LBT of the first starting symbol / position fails. For example, only when the number of (re)transmissions for PSSCH transmission is greater than or equal to a certain level (e.g., a (pre)configured value), the channel access attempt at the second starting symbol / position can be performed after the LBT of the first starting symbol / position fails. For example, if the SL priority value and / or the CAPC value is less than or equal to the (pre) configured threshold, a channel access attempt at the second starting symbol / position may be performed after the LBT at the first starting symbol / position fails. The reason for doing this is to provide more transmission opportunities for higher priority transmissions. For example, if the SL priority value and / or the CAPC value is equal to or greater than the (pre) configured threshold, a channel access attempt at the second starting symbol / position may be performed after the LBT at the first starting symbol / position fails. For example, after the LBT at the first starting symbol / position based on the type 1 channel access process fails, a channel access attempt at the second starting symbol / position may be performed based on a series of type 2 channel access processes. For example, in the case of a channel access attempt at the second starting symbol / position after the LBT at the first starting symbol / position based on the type 1 channel access process fails, the ongoing type 1 channel access process may be continuously performed. For example, after the LBT at the first starting symbol / position based on the type 2B channel access process fails, a channel access attempt at the second starting symbol / position may be performed based on the type 2A channel access process. For example, after the LBT at the first starting symbol / position based on the type 2A channel access procedure fails, a channel access attempt at the second starting symbol / position may be performed based on the type 2A channel access procedure. For example, in the case of a channel access attempt at the second starting symbol / position after the LBT at the first starting symbol / position based on the type 1 channel access procedure fails, the ongoing type 1 channel access procedure may be stopped, and a new type 1 channel access procedure may be performed again.

[0325] In an embodiment of the present disclosure, various schemes may be applied differently depending on the CAPC value and / or on the SL priority value and / or on the (remaining) counter value of the Type 1 channel access procedure and / or on the contention window size of the Type 1 channel access procedure.

[0326] At the same time, as part of a method having multiple starting symbols for PSCCH / PSSCH, multiple PSCCH / PSSCH resources in a time slot can be generated along the time domain. For example, by dividing 14 or 12 symbols within a time slot into 7 or 6, two PSCCH / PSSCH resources in the time slot can be ensured. At the same time, in the above structure, the PSSCH DMRS pattern may be limited to the case where the number of DMRS symbols is 2, and even this may be punctured by a portion of the first DMRS due to PSCCH transmission. In addition, in the above structure, PSFCH resources cannot be allocated, and therefore, operations based on SLHARQ-ACK may not be performed.

[0327] For example, in the case of having multiple PSCCH / PSSCH time resources in a time slot, 1 PSSCH DMRS symbol may be allowed for each PSCCH / PSSCH resource. For example, the PSSCH DMRS symbol may be mapped after the last symbol to which the PSCCH is mapped. For example, the PSSCH DMRS symbol may be mapped to the last symbol to which the PSSCH is mapped. For example, among the symbols included in the time slot, the first half may be allocated as a PSCCH / PSSCH resource, and the second half may be allocated as a single or multiple PSFCH resources. For example, in the case of a method of mapping multiple PSFCH resources to half of a time slot, a PSFCH including two symbols may be continuously connected without a gap, and all or part of the last symbol may be a TX-RX switching symbol. For example, among the symbols included in the time slot, the first half may be allocated as a single or multiple PSFCH resources, and the second half may be allocated as a PSCCH / PSSCH resource. For example, the position of the PSFCH resource within the time slot may be (pre)configured for each resource pool.

[0328] At the same time, after determining that LBT fails, the UE may not have enough time to switch back to SL reception operation during the duration of scheduled SL transmission. For example, if the UE fails to perform LBT for the sidelink transmission resource, the UE may skip the sidelink reception operation in the time resource (e.g., time slot) of the transmission resource. For example, if the sidelink reception operation is skipped after LBT fails, when the UE performs mode 2 resource (re)selection, the UE may regard the time slot in which the actual sidelink transmission is not performed as a non-monitoring time slot. For example, for the non-monitoring time slot within the sensing window, the UE may exclude from the available resources all resources of the time slot within the resource selection window derived from the resource reservation cycle value (pre) configured in the resource pool in the non-monitoring time slot for each candidate. For example, if the UE fails to perform LBT for the sidelink transmission resource at the first starting position, the UE may skip the sidelink reception at the first starting position and / or attempt the sidelink reception at the second starting position. For example, if the UE fails to perform LBT for the sidelink transmission resource, the UE may skip the sidelink reception operation for some time intervals in the time resource (e.g., time slot) for the transmission resource, and the UE may perform the reception operation for the subsequent time interval. For example, some time intervals may be restricted to within the CP length.For example, some time intervals may be restricted to the first symbol available for the sidelink or PSCCH / PSSCH.

[0329] At the same time, for transmission within a single RB set, the CP extension method may be different for the case where all PRBs within the RB set are used for transmission and for another case. For example, if the UE performs transmission on all PRBs within the RB set, the UE may determine the CP extension method and / or CP extension length differently depending on the CAPC value or SL priority value, and / or the UE may randomly select or determine the CP extension method and / or CP extension length from the CP extension length candidate values ​​(pre-) configured inside or outside each resource pool and / or COT and / or CAPC or SL priority. For example, if the UE performs transmission on some PRBs within the RB set, the UE may use the CP extension length (pre-) configured inside or outside each resource pool and / or COT and / or COT and / or CAPC or SL priority. At the same time, the UE may perform transmission for multiple RB sets, in which case it may be necessary to determine a method for performing CP extension. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses all PRBs in a specific RB set for transmission, and / or if the UE uses some PRBs in a specific RB set for transmission, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be the CP extension method and length in the case where the UE uses all PRBs in the RB set. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses all PRBs in a specific RB set for transmission, and / or if the UE uses some PRBs in a specific RB set for transmission, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be the CP extension method and length in the case where the UE uses some PRBs in the RB set. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses all PRBs in a specific RB set for transmission, and / or if the UE uses some PRBs in a specific RB set for transmission, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be the longer one of the CP extension methods and lengths derived by the UE in different ways. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses all PRBs in a specific RB set for transmission, and / or if the UE uses some PRBs in a specific RB set for transmission, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be a shorter one of the CP extension methods and lengths derived by the UE in different ways. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses all PRBs in a specific RB set for transmission, and / or if the UE uses some PRBs in a specific RB set for transmission, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be an average of the CP extension methods and lengths derived by the UE in different ways.For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses all PRBs in a specific RB set for transmission, and / or if the UE uses some PRBs in a specific RB set for transmission, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be values ​​that are individually (pre)configured by the UE. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses a single CP extension length for a specific RB set within a time slot, and / or if the UE selects and uses one of multiple CP extension lengths for a specific RB set within a time slot, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be the same as the case where the UE uses a single CP extension length within a time slot. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses a single CP extension length for a specific RB set within a time slot, and / or if the UE selects and uses one of multiple CP extension lengths for a specific RB set within a time slot, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be the same as the case where the UE selects and uses one of multiple CP extension lengths within the time slot. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses a single CP extension length for a specific RB set within a time slot, and / or if the UE selects and uses one of multiple CP extension lengths for a specific RB set within a time slot, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be a longer one of the CP extension methods and lengths derived by the UE in different ways. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses a single CP extension length for a specific RB set within a time slot, and / or if the UE selects and uses one of multiple CP extension lengths for a specific RB set within a time slot, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be a shorter one of the CP extension methods and lengths derived by the UE in different ways. For example, if the UE performs transmission on resources in multiple RB sets, and / or if the UE uses a single CP extension length for a specific RB set within a time slot, and / or if the UE selects and uses one of multiple CP extension lengths for a specific RB set within a time slot, the CP extension method and length used by the UE when performing transmission on all allocated RB sets may be an average of the CP extension methods and lengths derived by the UE in different ways. The basis for this is that a transition period may occur between time intervals when the frequency range used for transmission varies over time, and thus signal distortion may occur.

[0330] For example, when the UE uses resources of multiple RB sets for transmission, a CP extension method and / or length may be determined and applied differently for each RB set.

[0331] In an embodiment of the present disclosure, LBT failure may be limited to failures caused by a channel access procedure of a type 2 series. In an embodiment of the present disclosure, LBT failure may be limited to a case where the time interval between the time when the LBT failure is determined and the time when the transmission resource starts or the time immediately before the transmission resource corresponding to the LBT is less than or equal to a specific level.

[0332] In an embodiment of the present disclosure, the puncturing of a specific symbol may be limited to within the CP. In an embodiment of the present disclosure, the puncturing of a specific symbol may be restrictively applied to a duration other than the duration for performing the actual AGC. In an embodiment of the present disclosure, whether the CP is punctured in whole or in part and / or the length of the duration to be punctured may replace or extend whether or how the CP is extended. For example, whether all or part of the CP is punctured and / or the length of the duration to be punctured may be (pre) configured for each resource pool and / or each SL channel and / or the inside or outside of each COT and / or each CAPC value and / or each SL priority value and / or each CBR range and / or each channel access type. For example, whether all or part of the CP is punctured and / or the length of the duration to be punctured may be different for each resource pool and / or each SL channel and / or the inside or outside of each COT and / or each CAPC value and / or each SL priority value.

[0333] For example, if the UE fails to perform LBT for the previous symbol starting position, and / or if the UE fails to complete the LBT operation, and / or if the transmission of the previous symbol starting position is discarded due to prioritization procedures and / or congestion control, the UE may change the (next) symbol starting position used for PSCCH / PSSCH.

[0334] In an embodiment of the present disclosure, omitting all or part of the CP for side link transmission and / or reception may be applied in different ways depending on the target distance of the side link communication. For example, if the target distance of the side link communication is greater than or equal to a certain level, partial CP omission may not be allowed, and / or the interval length of CP omission may be (pre)configured differently.

[0335] For example, if two start symbols are enabled, when PSCCH / PSSCH is transmitted for the first start symbol, and / or when different symbols are repeated or an AGC sequence is mapped for each start symbol candidate, the PSSCH symbol duration or the reference symbol duration l_d may be a value excluding the second start symbol. For example, the UE may perform mapping on the second start symbol by duplicating symbols after mapping the DMRS according to the DMRS pattern for excluding the virtual symbol duration of the second start symbol.

[0336] For example, the UE may perform PSSCH mapping on the TX-RX switching symbol. In this case, the TX-RX switching symbol for which PSSCH mapping is performed may also be included in the PSSCH symbol duration or the reference symbol duration l_d. For example, in the above case, if the l_d value is 14, it may have the same DMRS pattern as when the l_d value is 13.

[0337] For example, the UE may perform PSSCH mapping on the TX-RX switching symbol. For example, in the above case, the TX-RX switching symbol to which the PSSCH is mapped may be excluded from the PSSCH symbol duration or the reference symbol duration length l_d.

[0338] For example, whether AGC destination mapping is performed on the second starting symbol candidate may be different for each MCS, coding rate, number of CBs, TBS, whether broadband transmission is performed, and / or whether it is inside or outside the COT. For example, whether AGC destination mapping is performed on the second starting symbol candidate may be (pre) configured for each MCS, coding rate, number of CBs, TBS, whether broadband transmission is performed, and / or whether it is inside or outside the COT.

[0339] For example, if the UE detects PSCCH / PSSCH for the 1st starting symbol of all RB sets (within the resource pool or within the SL BWP) (this may be limited to the case where a guard band exists in the SL carrier and / or SL BWP and / or SL resource pool), and / or if the PSSCH allocated by the PSCCH detected by the UE for the 1st starting symbol is mapped to all RB sets and / or all PRBs (within the resource pool or within the SL BWP) (this may be limited to the case where a guard band exists in the SL carrier and / or SL BWP and / or SL resource pool), and / or if reserved resources for the 2nd starting symbol are not identified, and / or if it is determined (via explicit or implicit indication) that the TXUE does not send a signal for the 2nd starting symbol index, the UE may omit the AGC operation for the 2nd starting symbol candidate.

[0340] In various embodiments of the present disclosure, the method may be applied differently for each SL channel and / or depending on whether PSCCH / PSSCH transmission by the UE is outside or inside the COT.

[0341] In various embodiments of the present disclosure, the method may be applied differently per SCS and / or per RB set and / or per RB set size.

[0342] For example, a configuration that allows multiple symbol starting positions for a side link channel (PSCCH / PSSCH) and / or a configuration that adjusts the starting position by CPE or CP puncturing may be used simultaneously. For example, whether to apply CPE or CP puncturing may be different based on multiple symbol starting positions, and / or the length candidates for CPE or CP puncturing may be different. For example, even if CPE is applied for the first symbol starting position, the UE may not apply CPE when attempting transmission for the next symbol starting position. For example, if the UE attempts to perform LBT on the first or previous symbol starting position, and / or if the LBT result is busy, and / or if the UE switches to a receiving operation after canceling the transmission of the first or previous symbol starting position, and / or if the UE detects SCI of another UE during the receiving operation, and / or if the PSSCH resource corresponding to the detected SCI overlaps with the transmission resource of the next symbol starting position of the UE, the UE may not attempt transmission for the next symbol starting position, and / or the UE may skip applying CPE when transmitting for the next symbol starting position. For example, based on the multiple symbol starting positions of the PSCCH / PSSCH transmission for the UE, whether CPE or CP puncturing is applied and its length may be the same. For example, if the UE selects the CPE length for the start of the previous symbol based on CAPC or SL priority and / or randomly, and if the UE attempts to transmit for the start of the next symbol, the UE may use the CPE length selected based on CAPC or SL priority and / or randomly as is.

[0343] For example, the UE may not desire to use a configuration that allows multiple symbol starting positions for sidelink channels (PSCCH / PSSCH) and / or a configuration that simultaneously adjusts the starting position through CPE or CP puncturing.

[0344] Based on various embodiments of the present disclosure, if multiple start symbols for PSCCH / PSSCH transmission are allowed within a time slot, it is possible to ensure that the UE determines that the transport block size (TBS) is the same. Therefore, the problem that the receiving UE performs independent decoding on the same TB, even if it is the same TB, can be solved. In addition, the problem that HARQ merging is impossible even if it is the same TB due to different TBSs can also be solved. In addition, based on the various embodiments of the present disclosure, multiple PSFCH opportunities can be allocated for one PSSCH. By this, the probability that the PSSCH receiving UE cannot perform PSFCH transmission due to LBT failure can be reduced. Therefore, for example, in the case of NACK-only feedback, the problem of NACK-to-ACK error (i.e., the problem of mistaking NACK for ACK) caused by PSFCH transmission loss can be minimized, and the reliability of SL communication can be improved. For example, in the case of ACK / NACK feedback, the problem of unnecessary retransmission due to ACK transmission loss can be minimized, and resources can be used efficiently.

[0345] Fig.14 A method for a first device to perform wireless communication based on an embodiment of the present disclosure is shown. Fig.14 The embodiments of the present disclosure may be combined with the embodiments of the present disclosure.

[0346] See also Fig.14 In step S1410, the first device may obtain information related to multiple candidate start symbols within a time slot for side link (SL) transmission. For example, the multiple candidate start symbols may include a first start symbol and a second start symbol. In step S1420, the first device may obtain the number of reference symbols for transport block size (TBS) determination. In step S1430, the first device may determine the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols. In step S1440, the first device may determine the TBS based on the number of REs allocated for the PSSCH.

[0347] For example, based on a number of candidate starting symbols allowed in a time slot, the number of REs allocated for the PSSCH in the time slot may be determined based on the number of reference symbols.

[0348] For example, the number of reference symbols may be configured or preconfigured for the first device.

[0349] For example, it may be determined that a TBS associated with a first SL transmission based on a first starting symbol and a TBS associated with a second SL transmission based on a second starting symbol are the same.

[0350] For example, based on the first device failing to listen before talk (LBT) on the first start symbol, the first device may be allowed to use the second start symbol.

[0351] In addition, for example, the first device may send first sidelink control information (SCI) for scheduling the second SCI and PSSCH to the second device via a physical sidelink control channel (PSCCH). In addition, for example, the first device may send the second SCI and data to the second device via the PSSCH.

[0352] In addition, for example, the first device may perform physical sidelink feedback channel (PSFCH) monitoring in N PSFCH opportunities related to the PSSCH. For example, N may be a positive integer greater than or equal to 2. For example, N may be configured or preconfigured for the first device. In addition, for example, the first device may receive the PSFCH from the second device in a PSFCH opportunity in which the second device successfully performs channel sensing among the N PSFCH opportunities.

[0353] For example, based on the information included in the first SCI or the second SCI, the starting symbol of the SL transmission can be determined from among multiple candidate starting symbols. For example, based on the information related to the number of PSSCH demodulation reference signal (DMRS) symbols included in the first SCI, the starting symbol of the SL transmission can be determined as a starting symbol that can support the number of PSSCH DMRS symbols among multiple candidate starting symbols. For example, based on the information related to the PSFCH overhead included in the second SCI, the starting symbol of the SL transmission can be determined as a starting symbol that can support the PSFCH overhead among multiple candidate starting symbols.

[0354] For example, a first energy detection threshold for channel sensing performed before a first start symbol may be configured differently from a second energy detection threshold for channel sensing performed before a second start symbol.

[0355] The proposed method can be applied to devices based on various embodiments of the present disclosure. First, the processor 102 of the first device 100 may obtain information related to multiple candidate start symbols within a time slot for side link (SL) transmission. For example, the multiple candidate start symbols may include a first start symbol and a second start symbol. In addition, the processor 102 of the first device 100 may obtain the number of reference symbols for transport block size (TBS) determination. In addition, the processor 102 of the first device 100 may determine the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols. In addition, the processor 102 of the first device 100 may determine the TBS based on the number of REs allocated for the PSSCH.

[0356] Based on an embodiment of the present disclosure, a first device adapted to perform wireless communication may be provided. For example, the first device may include: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instructions may be executed by at least one processor, and may cause the first device to perform operations including: obtaining information related to multiple candidate start symbols within a time slot for side link (SL) transmission, wherein the multiple candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0357] Based on an embodiment of the present disclosure, a processing device adapted to control a first device may be provided. For example, the processing device may include: at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instructions may be executed by at least one processor, and may cause the first device to perform operations including: obtaining information related to a plurality of candidate start symbols within a time slot for side link (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for determining a transport block size (TBS); determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0358] Based on an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions may be provided. For example, when the instructions are executed, the first device may perform operations including: obtaining information related to multiple candidate start symbols in a time slot for side link (SL) transmission, wherein the multiple candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) in the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0359] Fig.15 A method for a second device to perform wireless communication based on an embodiment of the present disclosure is shown. Fig.15 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0360] refer to Fig.15, in step S1510, the second device may obtain information related to multiple candidate start symbols within a time slot for side link (SL) reception. For example, the multiple candidate start symbols may include a first start symbol and a second start symbol. In step S1520, the second device may obtain the number of reference symbols for transport block size (TBS) determination. In step S1530, the second device may determine the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols. In step S1540, the second device may determine the TBS based on the number of REs allocated for the PSSCH.

[0361] For example, based on a plurality of candidate starting symbols allowed in a time slot, the number of REs allocated for the PSSCH in the time slot may be determined based on the number of reference symbols.

[0362] For example, the number of reference symbols may be configured or preconfigured for the second device.

[0363] For example, it may be determined that a TBS associated with a first SL reception based on a first start symbol and a TBS associated with a second SL reception based on a second start symbol are the same.

[0364] In addition, for example, the second device may receive first sidelink control information (SCI) for scheduling the second SCI and PSSCH from the first device through a physical sidelink control channel (PSCCH). In addition, for example, the second device may receive the second SCI and data from the first device through the PSSCH.

[0365] In addition, for example, the second device may perform channel sensing (e.g., LBT) on a physical sidelink feedback channel (PSFCH) transmission in N physical sidelink feedback channel (PSFCH) opportunities related to the PSSCH. For example, N may be a positive integer greater than or equal to 2. For example, N may be configured or preconfigured for the second device. In addition, for example, the second device may send a PSFCH to the first device in a PSFCH opportunity in which channel sensing is successful among the N PSFCH opportunities.

[0366] For example, based on the information included in the first SCI or the second SCI, the starting symbol received by the SL can be determined from among multiple candidate starting symbols. For example, based on the information related to the number of PSSCH demodulation reference signal (DMRS) symbols included in the first SCI, the starting symbol received by the SL can be determined as a starting symbol that can support the number of PSSCH DMRS symbols among multiple candidate starting symbols. For example, based on the information related to the PSFCH overhead included in the second SCI, the starting symbol received by the SL can be determined as a starting symbol that can support the PSFCH overhead among multiple candidate starting symbols.

[0367] The proposed method can be applied to devices based on various embodiments of the present disclosure. First, the processor 202 of the second device 200 may obtain information related to multiple candidate start symbols within a time slot for side link (SL) reception. For example, the multiple candidate start symbols may include a first start symbol and a second start symbol. In addition, the processor 202 of the second device 200 may obtain the number of reference symbols for transport block size (TBS) determination. In addition, the processor 202 of the second device 200 may determine the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within a time slot based on the number of reference symbols. In addition, the processor 202 of the second device 200 may determine the TBS based on the number of REs allocated for the PSSCH.

[0368] Based on an embodiment of the present disclosure, a second device adapted to perform wireless communication may be provided. For example, the second device may include: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instruction is based on being executed by at least one processor, which may cause the second device to perform operations including: obtaining information related to multiple candidate start symbols within a time slot for side link (SL) reception, wherein the multiple candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0369] Based on an embodiment of the present disclosure, a processing device adapted to control a second device may be provided. For example, the processing device may include: at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, based on being executed by at least one processor, the instruction may cause the second device to perform operations including: obtaining information related to multiple candidate start symbols within a time slot for side link (SL) reception, wherein the multiple candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) within the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0370] Based on the embodiments of the present disclosure, a non-transitory computer-readable storage medium storing instructions may be provided. For example, when the instruction is executed, the second device may be caused to perform operations including: obtaining information related to multiple candidate start symbols in a time slot for side link (SL) reception, wherein the multiple candidate start symbols include a first start symbol and a second start symbol; obtaining the number of reference symbols for transport block size (TBS) determination; determining the number of resource elements (REs) allocated for a physical side link shared channel (PSSCH) in the time slot based on the number of reference symbols; and determining the TBS based on the number of REs allocated for the PSSCH.

[0371] Various embodiments of the present disclosure may be combined with each other.

[0372] Hereinafter, devices to which various embodiments of the present disclosure can be applied will be described.

[0373] The various descriptions, functions, processes, proposals, methods and / or operational flows of the present disclosure described herein may be applied to, but not limited to, various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0374] Hereinafter, a description will be given in more detail with reference to the accompanying drawings. In the following drawings / descriptions, unless otherwise described, the same reference numerals may represent the same or corresponding hardware blocks, software blocks or functional blocks.

[0375] Fig.16 A communication system 1 according to an embodiment of the present disclosure is shown. Fig.16 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0376] refer to Fig.16, a communication system 1 to which various embodiments of the present disclosure are applied includes a wireless device, a base station (BS), and a network. Herein, a wireless device refers to a device that performs communication using a radio access technology (RAT) (e.g., 5G new RAT (NR) or long term evolution (LTE)), and may be referred to as a communication / radio / 5G device. The wireless device may include, without limitation, a robot 100a, a vehicle (100b-1, 100b-2), an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device / server 400. For example, a vehicle may include a vehicle with a wireless communication function, an autonomous vehicle, and a vehicle capable of performing inter-vehicle communication. Herein, a vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). XR devices may include augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices and may be implemented in the form of head mounted devices (HMDs), head up displays (HUDs) installed in vehicles, televisions, smart phones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Handheld devices may include smart phones, smart boards, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., notebooks). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters. For example, a BS and a network may be implemented as wireless devices, and a specific wireless device 200a may operate as a BS / network node relative to other wireless devices.

[0377] Here, in addition to LTE, NR and 6G, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may also include a narrowband Internet of Things for low-power communication. In this case, for example, the NB-IoT technology may be an example of a low-power wide area network (LPWAN) technology, and may be implemented as a standard such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may perform communication based on the LTE-M technology. In this case, as an example, the LTE-M technology may be an example of an LPWAN, and may be referred to as various names including enhanced machine type communication (eMTC), etc. For example, the LTE-M technology may be implemented as at least any one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE machine type communication and / or 7) LTE M, and is not limited to the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may include at least one of Bluetooth, a low power wide area network (LPWAN), and ZigBee considering low power communication, and is not limited to the above names. As an example, the ZigBee technology may generate a personal area network (PAN) related to small / low power digital communication based on various standards including IEEE 802.15.4, etc., and may be referred to by various names.

[0378] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. AI technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without going through the BS / network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0379] Wireless communication / connection 150a, 150b or 150c may be established between wireless devices 100a to 100f / BS 200 or BS200 / BS 200. Here, the wireless communication / connection may be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication 150b (or D2D communication) or inter-BS communication (e.g., relay, integrated access backhaul (IAB)). The wireless device and the BS / wireless device may send / receive radio signals to / from each other through wireless communication / connections 150a and 150b. For example, wireless communication / connections 150a and 150b may send / receive signals through various physical channels. To this end, various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and at least a portion of a resource allocation process may be performed based on various proposals of the present disclosure.

[0380] Fig.17 A wireless device according to an embodiment of the present disclosure is shown. Fig.17 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0381] refer to Fig.17 , the first wireless device 100 and the second wireless device 200 may transmit radio signals via various RATs (eg, LTE and NR). Herein, {the first wireless device 100 and the second wireless device 200} may correspond to Fig.16 {wireless device 100x and BS200} and / or {wireless device 100x and wireless device 100x} in.

[0382] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and may also additionally include one or more transceivers 106 and / or one or more antennas 108. The (one or more) processors 102 may control the (one or more) memories 104 and / or the (one or more) transceivers 106, and may be configured to implement the descriptions, functions, processes, proposals, methods and / or operation flows disclosed in this document. For example, the (one or more) processors 102 may process the information in the (one or more) memories 104 to generate first information / signals, and then send a radio signal including the first information / signals through the (one or more) transceivers 106. The (one or more) processors 102 may receive a radio signal including a second information / signal through the transceiver 106, and then store the information obtained by processing the second information / signals in the (one or more) memories 104. The memory (one or more) 104 may be connected to the processor (one or more) 102 and may store various information related to the operation of the processor (one or more) 102. For example, the memory (one or more) 104 may store software code including instructions for executing part or all of the processing controlled by the processor (one or more) 102 or for executing the description, function, process, proposal, method and / or operation flow disclosed in this document. Here, the processor (one or more) 102 and the memory (one or more) 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver (one or more) 106 may be connected to the processor (one or more) 102 and transmit and / or receive radio signals through the antenna (one or more) 108. Each transceiver 106 may include a transmitter and / or a receiver. The transceiver (one or more) 106 may be used interchangeably with the radio frequency (RF) unit (one or more). In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0383] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and may also additionally include one or more transceivers 206 and / or one or more antennas 208. The (one or more) processors 202 may control the (one or more) memories 204 and / or the (one or more) transceivers 206, and may be configured to implement the descriptions, functions, processes, proposals, methods and / or operation flows disclosed in this document. For example, the (one or more) processors 202 may process the information in the (one or more) memories 204 to generate third information / signals, and then send a radio signal including the third information / signals through the (one or more) transceivers 206. The (one or more) processors 202 may receive a radio signal including a fourth information / signal through the (one or more) transceivers 106, and then store the information obtained by processing the fourth information / signals in the (one or more) memories 204. The memory (one or more) 204 may be connected to the processor (one or more) 202 and may store various information related to the operation of the processor (one or more) 202. For example, the memory (one or more) 204 may store software code including commands for executing part or all of the processing controlled by the processor (one or more) 202 or for executing the description, function, process, proposal, method and / or operation flow disclosed in this document. Here, the processor (one or more) 202 and the memory (one or more) 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver (one or more) 206 may be connected to the processor (one or more) 202 and transmit and / or receive radio signals through the antenna (one or more) 208. Each transceiver 206 may include a transmitter and / or a receiver. The transceiver (one or more) 206 may be used interchangeably with the RF unit (one or more). In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0384] Below, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by, but are not limited to, one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). One or more processors 102 and 202 may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the descriptions, functions, processes, proposals, methods, and / or operating procedures disclosed in this document. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operating procedures disclosed in this document. One or more processors 102 and 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the description, function, process, proposal, method, and / or operation flow disclosed in this document, and provide the generated signal to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106 and 206, and obtain the PDU, SDU, message, control information, data, or information according to the description, function, process, proposal, method, and / or operation flow disclosed in this document.

[0385] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. The descriptions, functions, processes, proposals, methods, and / or operational flows disclosed in this document may be implemented using firmware or software, and the firmware or software may be configured to include modules, processes, or functions. Firmware or software configured to execute the descriptions, functions, processes, proposals, methods, and / or operational flows disclosed in this document may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204, thereby being driven by one or more processors 102 and 202. The descriptions, functions, processes, proposals, methods and / or operational flows disclosed in this document may be implemented using software or firmware in the form of codes, commands and / or command sets.

[0386] One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and may store various types of data, signals, messages, information, programs, codes, instructions, and / or commands. One or more memories 104 and 204 may be composed of read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard drive, register, cash memory, computer-readable storage medium, and / or a combination thereof. One or more memories 104 and 204 may be located inside and / or outside one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 via various technologies such as wired or wireless connections.

[0387] One or more transceivers 106 and 206 may send user data, control information and / or radio signals / channels mentioned in the method and / or operation flow of this document to one or more other devices. One or more transceivers 106 and 206 may receive user data, control information and / or radio signals / channels mentioned in the description, function, process, proposal, method and / or operation flow disclosed in this document from one or more other devices. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202, and may send and receive radio signals. For example, one or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may send user data, control information or radio signals to one or more other devices. One or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may receive user data, control information or radio signals from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208, and one or more transceivers 106 and 206 may be configured to send and receive user data, control information and / or radio signals / channels mentioned in the description, functions, processes, proposals, methods and / or operation flows disclosed in this document through one or more antennas 108 and 208. In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106 and 206 may convert received radio signals / channels, etc. from RF band signals to baseband signals to process received user data, control information, radio signals / channels, etc. using one or more processors 102 and 202. One or more transceivers 106 and 206 may convert user data, control information, radio signals / channels, etc. processed using one or more processors 102 and 202 from baseband signals to RF band signals. To this end, one or more of the transceivers 106 and 206 may include (analog) oscillators and / or filters.

[0388] Fig.18 A signal processing circuit for transmitting a signal according to an embodiment of the present disclosure is shown. Fig.18 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0389] refer to Fig.18 The signal processing circuit 1000 may include a scrambler 1010, a modulator 1020, a layer mapper 1030, a precoder 1040, a resource mapper 1050, and a signal generator 1060. Fig.18 Operation / function, not limited to Fig.17The processor (102, 202) and / or transceiver (106, 206) of Fig.17 The processor (102, 202) and / or the transceiver (106, 206) are implemented Fig.18 For example, you can Fig.17 The processor (102, 202) implements blocks 1010 to 1060. Alternatively, Fig.17 The processor (102, 202) implements blocks 1010 to 1050 and can be Fig.17 The transceiver (106, 206) is used to implement block 1060.

[0390] Can be through Fig.18 The signal processing circuit 1000 converts the codeword into a radio signal. Herein, the codeword is a coded bit sequence of an information block. The information block may include a transport block (e.g., UL-SCH transport block, DL-SCH transport block). The radio signal may be transmitted through various physical channels (e.g., PUSCH and PDSCH).

[0391] Specifically, the codeword can be converted into a scrambled bit sequence by the scrambler 1010. The scrambling sequence for scrambling can be generated based on an initial value, and the initial value can include the ID information of the wireless device. The scrambled bit sequence can be modulated into a modulation symbol sequence by the modulator 1020. The modulation scheme may include pi / 2-binary phase shift keying (pi / 2-BPSK), m-phase shift keying (m-PSK), and m-quadrature amplitude modulation (m-QAM). The complex modulation symbol sequence can be mapped to one or more transmission layers by the layer mapper 1030. The modulation symbol of each transmission layer can be mapped (precoded) to (one or more) corresponding antenna ports by the precoder 1040. The output z of the precoder 1040 can be obtained by multiplying the output y of the layer mapper 1030 with the N*M precoding matrix W. Here, N is the number of antenna ports and M is the number of transmission layers. The precoder 1040 can perform precoding after performing transform precoding (e.g., DFT) for the complex modulation symbol. Alternatively, the precoder 1040 may perform precoding without performing transform precoding.

[0392] The resource mapper 1050 may map the modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include multiple symbols in the time domain (e.g., CP-OFDMA symbols and DFT-s-OFDMA symbols) and multiple subcarriers in the frequency domain. The signal generator 1060 may generate a radio signal from the mapped modulation symbols, and the generated radio signal may be sent to other devices through each antenna. To this end, the signal generator 1060 may include an inverse fast Fourier transform (IFFT) module, a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), and an up-converter.

[0393] Can Fig.18 The signal processing process for the signal received in the wireless device is configured in a manner opposite to the signal processing process (1010-1060) of the wireless device. For example, the wireless device (e.g., Fig.17 100, 200) can receive a radio signal from the outside through an antenna port / transceiver. The received radio signal can be converted into a baseband signal by a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Next, the baseband signal can be restored to a codeword through a resource demapping process, a post-coding process, a demodulation processor, and a descrambling process. The codeword can be restored to the original information block by decoding. Therefore, a signal processing circuit (not illustrated) for receiving a signal may include a signal restorer, a resource demapper, a post-encoder, a demodulator, a descrambler, and a decoder.

[0394] Fig.19 Another example of a wireless device based on an embodiment of the present disclosure is shown. The wireless device can be implemented in various forms according to use cases / services (see Fig.16 ). Fig.19 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0395] refer to Fig.19 , the wireless device (100, 200) may correspond to Fig.17 The wireless devices (100, 200) may be configured by various elements, components, units / parts and / or modules. For example, each of the wireless devices (100, 200) may include a communication unit 110, a control unit 120, a storage unit 130 and an additional component 140. The communication unit may include a communication circuit 112 and (one or more) transceivers 114. For example, the communication circuit 112 may include Fig.17 One or more processors (102, 202) and / or one or more memories (104, 204) of the present invention. For example, the transceiver(s) 114 may include Fig.17The control unit 120 is electrically connected to the communication unit 110, the memory 130, and the additional components 140, and controls the overall operation of the wireless device. For example, the control unit 120 can control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the storage unit 130. The control unit 120 can send the information stored in the storage unit 130 to the outside (e.g., other communication devices) via the communication unit 110 through a wireless / wired interface, or store the information received from the outside (e.g., other communication devices) via the communication unit 110 through a wireless / wired interface in the storage unit 130.

[0396] The additional component 140 may be configured in various ways depending on the type of wireless device. For example, the additional component 140 may include at least one of a power unit / battery, an input / output (I / O) unit, a drive unit, and a computing unit. The wireless device may be implemented in the following forms without limitation: a robot ( Fig.16 100a), vehicles ( Fig.16 100b-1 and 100b-2), XR devices ( Fig.16 100c), handheld devices ( Fig.16 100d), household appliances ( Fig.16 100e), IoT devices ( Fig.16 100f), digital broadcasting terminals, hologram equipment, public safety equipment, MTC equipment, medical equipment, fintech equipment (or financial equipment), security equipment, climate / environmental equipment, AI servers / equipment ( Fig.16 400), BS ( Fig.16 200), network nodes, etc. Depending on the use case / service, wireless devices can be used in mobile or fixed places.

[0397] exist Fig.19In the wireless device (100, 200), various elements, components, units / parts and / or modules in the wireless device (100, 200) can all be connected to each other through a wired interface, or at least part of them can be wirelessly connected through the communication unit 110. For example, in each of the wireless devices (100, 200), the control unit 120 and the communication unit 110 can be connected by wire, and the control unit 120 and the first unit (e.g., 130, 140) can be wirelessly connected through the communication unit 110. Each element, component, unit / part and / or module within the wireless device (100, 200) can also include one or more elements. For example, the control unit 120 can be constructed by a set of one or more processors. As an example, the control unit 120 can be constructed by a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing unit, and a memory control processor. As another example, the memory 130 can be constructed by a random access memory (RAM), a dynamic RAM (DRAM), a read-only memory (ROM), a flash memory, a volatile memory, a non-volatile memory, and / or a combination thereof.

[0398] Hereinafter, the implementation will be described in detail with reference to the accompanying drawings. Fig.19 .

[0399] Fig. 20 A handheld device based on an embodiment of the present disclosure is shown. The handheld device may include a smart phone, a smart board, a wearable device (e.g., a smart watch or smart glasses), or a portable computer (e.g., a notebook). The handheld device may be referred to as a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS), or a wireless terminal (WT). Fig. 20 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0400] refer to Fig. 20 , the handheld device 100 may include an antenna unit (108), a communication unit 110, a control unit 120, a storage unit 130, a power supply unit 140a, an interface unit 140b and an I / O unit 140c. The antenna unit 108 may be configured as a part of the communication unit 110. Blocks 110 to 130 / 140a to 140c correspond to Fig.19 Frame 110 to 130 / 140.

[0401] The communication unit 110 may send and receive signals (e.g., data signals and control signals) to and from other wireless devices or BSs. The control unit 120 may perform various operations by controlling the constituent elements of the handheld device 100. The control unit 120 may include an application processor (AP). The storage unit 130 may store data / parameters / programs / codes / commands required to drive the handheld device 100. The storage unit 130 may store input / output data / information. The power supply unit 140a may supply power to the handheld device 100 and include a wired / wireless charging circuit, a battery, etc. The interface unit 140b may support the connection of the handheld device 100 to other external devices. The interface unit 140b may include various ports (e.g., audio I / O ports and video I / O ports) for connecting to external devices. The I / O unit 140c may input or output video information / signals, audio information / signals, data and / or information input by a user. The I / O unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker and / or a tactile module.

[0402] For example, in the case of data communication, the I / O unit 140c can obtain information / signals (e.g., touch, text, voice, image, or video) input by the user, and the obtained information / signals can be stored in the storage unit 130. The communication unit 110 can convert the information / signals stored in the memory into radio signals, and directly send the converted radio signals to other wireless devices or to the BS. The communication unit 110 can receive radio signals from other wireless devices or BSs, and then restore the received radio signals to the original information / signals. The restored information / signals can be stored in the storage unit 130, and can be output as various types (e.g., text, voice, image, video, or tactile) through the I / O unit 140.

[0403] Fig.21 A vehicle or autonomous vehicle based on an embodiment of the present disclosure is shown. The vehicle or autonomous vehicle can be implemented by a mobile robot, a car, a train, a manned / unmanned aerial vehicle (AV), a ship, etc. Fig.21 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0404] refer to Fig.21 , the vehicle or autonomous vehicle 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a drive unit 140a, a power supply unit 140b, a sensor unit 140c, and an autonomous driving unit 140d. The antenna unit 108 may be configured as a part of the communication unit 110. Blocks 110 / 130 / 140a to 140d correspond to Fig.19 Frame 110 / 130 / 140.

[0405] The communication unit 110 may send and receive signals (e.g., data signals and control signals) to and from external devices such as other vehicles, BSs (e.g., gNBs and roadside units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or autonomous vehicle 100. The control unit 120 may include an electronic control unit (ECU). The drive unit 140a may cause the vehicle or autonomous vehicle 100 to travel on the road. The drive unit 140a may include an engine, a motor, a transmission system, wheels, brakes, a steering device, etc. The power supply unit 140b may supply power to the vehicle or autonomous vehicle 100 and may include a wired / wireless charging circuit, a battery, etc. The sensor unit 140c may acquire vehicle status, external environment information, user information, etc. The sensor unit 140c may include an inertial measurement unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, a lighting sensor, a pedal position sensor, etc. The autonomous driving unit 140d can implement technology for maintaining the lane in which the vehicle is traveling, technology for automatically adjusting the speed (e.g., adaptive cruise control), technology for autonomously driving along a determined path, technology for driving by automatically setting a path with a destination set, and the like.

[0406] For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d may generate an autonomous driving path and a driving plan from the acquired data. The control unit 120 may control the drive unit 140a so that the vehicle or autonomous vehicle 100 may move along the autonomous driving path according to the driving plan (e.g., speed / direction control). In the middle of autonomous driving, the communication unit 110 may aperiodically / periodically acquire the most recent traffic information data from an external server and acquire surrounding traffic information data from adjacent vehicles. In the middle of autonomous driving, the sensor unit 140c may acquire vehicle status and / or surrounding environment information. The autonomous driving unit 140d may update the autonomous driving path and driving plan based on the newly acquired data / information. The communication unit 110 may transmit information about the vehicle position, autonomous driving path, and / or driving plan to an external server. The external server may predict traffic information data using AI technology, etc. based on information collected from the vehicle or autonomous vehicle, and provide the predicted traffic information data to the vehicle or autonomous vehicle.

[0407] The claims in this specification can be combined in various ways. For example, the technical features in the method claims of this specification can be combined to be implemented or performed in a device, and the technical features in the device claims can be combined to be implemented or performed in a method. In addition, the technical features in (one or more) method claims and (one or more) device claims can be combined to be implemented or performed in a device. In addition, the technical features in (one or more) method claims and (one or more) device claims can be combined to be implemented or performed in a method.

Claims

1. A method for performing wireless communication by a first device, the method comprising: obtaining information related to a plurality of candidate start symbols within a time slot for a sidelink (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) within the time slot based on the number of reference symbols; as well as A TBS is determined based on the number of REs allocated for the PSSCH.

2. The method according to claim 1, wherein: Based on allowing the plurality of candidate starting symbols in the time slot, the number of REs allocated for the PSSCH in the time slot is determined based on the number of reference symbols.

3. The method according to claim 1, wherein: The number of the reference symbols is configured or preconfigured for the first device.

4. The method according to claim 1, wherein: A TBS associated with a first SL transmission based on the first start symbol and a TBS associated with a second SL transmission based on the second start symbol are determined to be the same.

5. The method according to claim 1, wherein: Based on the first device failing to perform listen before talk (LBT) on the first start symbol, the first device is allowed to use the second start symbol.

6. The method according to claim 1, further comprising: Sending first sidelink control information (SCI) to the second device via a physical sidelink control channel (PSCCH), wherein the first SCI is used to schedule a second SCI and the PSSCH; as well as The second SCI and data are sent to the second device through the PSSCH.

7. The method according to claim 6, further comprising: performing physical sidelink feedback channel (PSFCH) monitoring in N PSFCH opportunities associated with said PSSCH, Wherein, N is a positive integer greater than or equal to 2.

8. The method according to claim 7, wherein: The N is configured or pre-configured for the first device.

9. The method according to claim 7, further comprising: A PSFCH is received from the second device in a PSFCH opportunity in which the second device successfully performs channel sensing among the N PSFCH opportunities.

10. The method according to claim 6, wherein: Based on the information included in the first SCI or the second SCI, a starting symbol for the SL transmission is determined from among the multiple candidate starting symbols.

11. The method according to claim 10, wherein: Based on information related to the number of PSSCH demodulation reference signal (DMRS) symbols included in the first SCI, the start symbol of the SL transmission is determined to be a start symbol that can support the number of the PSSCH DMRS symbols among the multiple candidate start symbols.

12. The method according to claim 10, wherein: Based on the information related to the PSFCH overhead included in the second SCI, the starting symbol of the SL transmission is determined to be a starting symbol that can support the PSFCH overhead among the multiple candidate starting symbols.

13. The method according to claim 1, wherein: A first energy detection threshold for channel sensing performed before the first start symbol is different from a second energy detection threshold configuration for channel sensing performed before the second start symbol.

14. A first device adapted to perform wireless communication, the first device comprising: at least one transceiver; at least one processor; as well as at least one memory connected to the at least one processor and storing instructions, the instructions causing the first device to perform operations upon execution by the at least one processor, the operations comprising: obtaining information related to a plurality of candidate start symbols within a time slot for a sidelink (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) within the time slot based on the number of reference symbols; as well as A TBS is determined based on the number of REs allocated for the PSSCH.

15. A processing device adapted to control a first device, the processing device comprising: at least one processor; as well as at least one memory connected to the at least one processor and storing instructions, the instructions causing the first device to perform operations upon execution by the at least one processor, the operations comprising: obtaining information related to a plurality of candidate start symbols within a time slot for a sidelink (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) within the time slot based on the number of reference symbols; as well as A TBS is determined based on the number of REs allocated for the PSSCH.

16. A non-transitory computer-readable storage medium storing instructions that, when executed, cause a first device to perform operations comprising: obtaining information related to a plurality of candidate start symbols within a time slot for a sidelink (SL) transmission, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) within the time slot based on the number of reference symbols; as well as A TBS is determined based on the number of REs allocated for the PSSCH.

17. A method for performing wireless communication by a second device, the method comprising: obtaining information related to a plurality of candidate start symbols within a time slot for sidelink (SL) reception, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) within the time slot based on the number of reference symbols; as well as A TBS is determined based on the number of REs allocated for the PSSCH.

18. A second device adapted to perform wireless communication, the second device comprising: at least one transceiver; at least one processor; as well as at least one memory connected to the at least one processor and storing instructions, the instructions, upon being executed by the at least one processor, causing the second device to perform operations, the operations comprising: obtaining information related to a plurality of candidate start symbols within a time slot for sidelink (SL) reception, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) within the time slot based on the number of reference symbols; as well as A TBS is determined based on the number of REs allocated for the PSSCH.

19. A processing device adapted to control a second device, the processing device comprising: at least one processor; as well as at least one memory connected to the at least one processor and storing instructions, the instructions, upon being executed by the at least one processor, causing the second device to perform operations, the operations comprising: obtaining information related to a plurality of candidate start symbols within a time slot for sidelink (SL) reception, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) within the time slot based on the number of reference symbols; as well as A TBS is determined based on the number of REs allocated for the PSSCH.

20. A non-transitory computer-readable storage medium storing instructions that, when executed, cause the second device to perform operations comprising: obtaining information related to a plurality of candidate start symbols within a time slot for sidelink (SL) reception, wherein the plurality of candidate start symbols include a first start symbol and a second start symbol; obtaining a number of reference symbols for transport block size (TBS) determination; determining a number of resource elements (REs) allocated for a physical sidelink shared channel (PSSCH) within the time slot based on the number of reference symbols; as well as A TBS is determined based on the number of REs allocated for the PSSCH.

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