Method and apparatus for performing sidelink communication in unlicensed spectrum

Abstract

A method performed by a first device in a wireless communication system and a device supporting the same are provided. A method performed by a first apparatus in a wireless communication system comprises the steps of: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); transmitting, to the second device over a physical sidelink control channel (PSCCH), a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI); transmitting the data and a second SCI to a second device through the PSSCH, the second SCI including information indicating a hybrid automatic repeat request (HARQ) feedback enabling mode; and determining a PSFCH resource related to the PSSCH based on the configuration information. Here, the HARQ feedback mode is changed from the HARQ feedback enabling mode to the HARQ feedback disabling mode on the basis that the number of PSFCH receptions from the second device has been ignored due to a listen before talk (LBT) failure has reached a threshold value.

Description

Technical Field

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

[0002] Sidelink (SL) refers to a communication method in which a direct link is configured between user equipment (UE) to directly exchange voice or data between user equipment 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) refers to 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 the Uu interface.

[0003] In addition, as more and more communication devices require greater communication capacity, the demand for enhanced mobile broadband communication compared to previous radio access technologies (RAT) is rising. Therefore, communication systems for reliability and latency-sensitive services or user equipment (UE) are discussed. And, the next generation of 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] According to an embodiment, a method performed by a first device may be provided. The method may include: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); sending a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) to a second device on a physical sidelink control channel (PSCCH); sending a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode; and determining a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device that are skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enable mode to a HARQ feedback disable mode.

[0006] According to an embodiment, a first device configured to perform wireless communication may be provided. The first device may include: at least one transceiver; at least one processor; and at least one memory connected to at least one processor and storing instructions. For example, the instructions are based on being executed by at least one processor so that the first device performs operations, the operations including: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); sending a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) to a second device on a physical sidelink control channel (PSCCH); sending a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode; and determining a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device that are skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enable mode to a HARQ feedback disable mode.

[0007] According to an embodiment, a processing device configured to control a first device may be provided. The processing device may include: at least one processor; and at least one memory connected to at least one processor and storing instructions. For example, the instructions are based on being executed by at least one processor so that the first device performs operations, the operations including: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); sending a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) to a second device on a physical sidelink control channel (PSCCH); sending a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode; and determining a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device that are skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enable mode to a HARQ feedback disable mode.

[0008] According to an embodiment, a non-transitory computer-readable storage medium storing instructions may be provided. The instructions are executed to cause a first device to perform operations, the operations including: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); sending a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) to a second device on a physical sidelink control channel (PSCCH); sending a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode; and determining a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device that are skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enable mode to a HARQ feedback disable mode. 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 The electromagnetic spectrum according to an embodiment of the present disclosure is shown.

[0011] Figure 3 The structure of the NR system based on 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 the radio frame of NR based on the 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 according to 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 An example of a wireless communication system supporting a license-free band according to an embodiment of the present disclosure is shown.

[0020] Fig.12 A method for occupying resources in an unlicensed frequency band according to an embodiment of the present disclosure is shown.

[0021] Fig.13 A case in which a plurality of LBT-SBs are included in a license-exempt band according to an embodiment of the present disclosure is shown.

[0022] Fig.14 A CAP operation performed by a base station to transmit a downlink signal through an unlicensed frequency band according to an embodiment of the present disclosure is shown.

[0023] Fig.15 A Type 1 CAP operation performed by a UE to transmit an uplink signal according to an embodiment of the present disclosure is shown.

[0024] Fig.16 The channel access process according to the embodiment of the present disclosure is shown.

[0025] Fig.17 An implementation of the UE switching resource allocation mode due to SL LBT failure based on an implementation of the present disclosure is shown.

[0026] Fig.18 An implementation of switching the HARQ feedback mode due to SL LBT failure based on an implementation of the present disclosure is shown.

[0027] Fig.19 A method for performing wireless communication by a first device according to an embodiment of the present disclosure is shown.

[0028] Fig. 20 A method for performing wireless communication by a second device according to an embodiment of the present disclosure is shown.

[0029] Fig.21 A communication system 1 according to an embodiment of the present disclosure is shown.

[0030] Fig. 22 A wireless device according to an embodiment of the present disclosure is shown.

[0031] Fig.23 A signal processing circuit for transmitting a signal according to an embodiment of the present disclosure is shown.

[0032] Fig.24 Another example of a wireless device according to an embodiment of the present disclosure is shown.

[0033] Fig.25 A handheld device according to an embodiment of the present disclosure is shown.

[0034] Fig.26 A vehicle or autonomous vehicle according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0035] 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".

[0036] 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".

[0037] 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".

[0038] 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".

[0039] In addition, brackets used in the present disclosure may mean "for example". Specifically, when indicated as "control information (PDCCH)", this may mean proposing "PDCCH" 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 (i.e., PDCCH)", this may also mean proposing "PDCCH" as an example of "control information".

[0040] In the following description, "when, if, or in the event of" may be replaced with "based on".

[0041] The technical features respectively described in one drawing in the present disclosure may be implemented separately or may be implemented simultaneously.

[0042] 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.

[0043] The techniques described below can 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 can be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA-2000. TDMA can 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 can 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) using E-UTRA. 3GPP LTE uses OFDMA in the downlink and SC-FDMA in the uplink. LTE-Advanced (LTE-A) is an evolution of LTE.

[0044] 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.

[0045] 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 Table 1 below. That is, Table 1 shows the requirements of the 6G system.

[0046] [Table 1]

[0047] Peak data rate per device 1Tbps E2E Latency 1ms Maximum spectral efficiency 100bps / Hz Mobility support Up to 1000 km / h Satellite Integration Completely AI Completely Autonomous Vehicles Completely XR Completely Tactile communication Completely

[0048] 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.

[0049] 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 invention can be combined with various embodiments of the present disclosure.

[0050] 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 delay 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.

[0051] -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.

[0052] -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 described below).

[0053] - Seamless integration of wireless information and energy transfer: 6G wireless networks can transmit power to facilitate charging the batteries of devices such as smartphones and sensors. Therefore, wireless information and energy transfer (WIET) will be integrated.

[0054] -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 ubiquity.

[0055] Among the new network features of 6G, several general requirements are as follows.

[0056] - 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, the small cell network is an essential feature of the 5G and beyond 5G (5GB) communication system. Therefore, the 6G communication system also adopts the characteristics of the small cell network.

[0057] -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.

[0058] - High Capacity Backhaul: Backhaul connections are characterized by high capacity backhaul networks in order to support high capacity traffic. High speed optical fiber and free space optics (FSO) systems can be possible solutions to this problem.

[0059] - 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.

[0060] -Software and virtualization: Software and virtualization are two important functions that are the basis of the design process in 5GB networks in order to ensure flexibility, reconfigurability and programmability.

[0061] The core implementation technology of the 6G system is described below.

[0062] - 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 methods 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.

[0063] -THz (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 considered to be 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 The 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 frequency band. Therefore, advanced adaptive placement techniques that can overcome range limitations can be used.

[0064] - Massive MIMO technology (Large MIMO)

[0065] -Holographic Beamforming (HBF)

[0066] -Optical wireless technology

[0067] - Free Space Optical Backhaul Network (FSO Backhaul Network)

[0068] -Non-Terrestrial Network (NTN)

[0069] -Quantum communication

[0070] - No cellular communication

[0071] -Integration of wireless information and power transmission

[0072] -Integration of wireless communication and sensing

[0073] -Integrated access and backhaul network

[0074] -Big Data Analysis

[0075] - Reconfigurable smart surface

[0076] -Metaverse

[0077] -Blockchain

[0078] - Unmanned Aerial Vehicles (UAV): Unmanned aerial vehicles (UAV) or drones will become an important factor in 6G wireless communications. In most cases, UAV technology is used to provide high-speed data wireless connections. A base station entity is installed inside the UAV to provide cellular connectivity. UAVs have certain features that are not sought in fixed base station infrastructure, such as ease of deployment, strong line-of-sight links, and freedom of mobility control. During emergencies such as natural disasters, it is economically unfeasible 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.

[0079] -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.

[0080] 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.

[0081] Figure 3 The structure of the NR system based on 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.

[0082] Reference 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.

[0083] Figure 3 The embodiment of the present invention illustrates a case where only gNB is included. BS20 may be connected to each other via an Xn interface. BS20 may be connected to each other via a fifth generation (5G) core network (5GC) and an NG interface. More specifically, BS20 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.

[0084] 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.

[0085] 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) in FIG. 5 shows a radio protocol stack of a control plane for Uu communication. Figure 4 (c) in FIG. 1 shows a radio protocol stack of a user plane for SL communication, and Figure 4 (d) in FIG. 5 shows a radio protocol stack of a control plane for SL communication.

[0086] Reference 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.

[0087] Data is transmitted through a physical channel between different physical layers (ie, a PHY layer of a transmitter and a PHY layer of a receiver). The physical channel may be modulated using an Orthogonal Frequency Division Multiplexing (OFDM) scheme, and uses time and frequency as radio resources.

[0088] The MAC layer provides services to the Radio Link Control (RLC) layer via logical channels, and the RLC layer is a higher layer of the MAC layer. 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.

[0089] 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).

[0090] 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 networks 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).

[0091] The functions of the Packet Data Convergence Protocol (PDCP) in the user plane include transmission, header compression and encryption of user data. The functions of the Packet Data Convergence Protocol (PDCP) in the control plane include transmission and encryption / integrity protection of control plane data.

[0092] 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.

[0093] 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.

[0094] When the 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 can be in the RRC idle (RRC_IDLE) state. In the case of NR, the RRC inactive (RRC_INACTIVE) state is additionally defined, and the UE in the RRC_INACTIVE state can maintain the connection with the core network and release its connection with the BS.

[0095] 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.

[0096] Examples of logical channels belonging to a higher layer of a transport channel and mapped to a 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.

[0097] 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.

[0098] Reference Figure 5In NR, a radio frame can be used to perform uplink and downlink transmissions. The length of a radio frame is 10ms and can be defined as consisting of two half frames (HF). A half frame can include five 1ms subframes (SF). A subframe (SF) can be divided into one or more time slots, and the number of time slots within a subframe can be determined according to the subcarrier spacing (SCS). Each time slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0099] 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).

[0100] 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 ).

[0101] [Table 2]

[0102]

[0103] In the NR system, OFDM (A) parameter sets (e.g., SCS, CP length, etc.) between multiple cells integrated into one UE may be configured differently. Therefore, the (absolute time) duration (or interval) of a time resource (e.g., a subframe, a time slot, or a 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.

[0104] In NR, multiple parameter sets or SCSs can be supported to support various 5G services. For example, with an SCS of 15kHz, a wide range of traditional cellular bands can be supported, and with an SCS of 30kHz / 60kHz, dense cities, lower latency, and wider carrier bandwidths can be supported. With an SCS of 60kHz or higher, bandwidths greater than 24.25GHz can be used to overcome phase noise.

[0105] 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).

[0106] [Table 3]

[0107] Frequency range specification Corresponding frequency range Subcarrier Spacing (SCS) FR1 450MHz–6000MHz 15, 30, 60kHz FR2 24250MHz–52600MHz 60, 120, 240kHz

[0108] 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 frequency bands. Unlicensed frequency bands may be used for various purposes, for example, unlicensed frequency bands are used for vehicle-specific communications (e.g., autonomous driving).

[0109] [Table 4]

[0110] Frequency range specification Corresponding frequency range Subcarrier Spacing (SCS) FR1 410MHz–7125MHz 15, 30, 60kHz FR2 24250MHz–52600MHz 60, 120, 240kHz

[0111] 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.

[0112] Reference 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.

[0113] A carrier includes multiple subcarriers in the frequency domain. A resource block (RB) can be defined as multiple consecutive subcarriers in the frequency domain (e.g., 12 subcarriers). A bandwidth part (BWP) can be defined as multiple consecutive (physical) resource blocks ((P)RBs) in the frequency domain, and a BWP can correspond to a parameter set (e.g., SCS, CP length, etc.). A carrier can include up to N BWPs (e.g., 5 BWPs). Data communication can be performed via an activated BWP. Each element can be referred to as a resource element (RE) in a resource grid, and a complex symbol can be mapped to each element.

[0114] Hereinafter, the bandwidth part (BWP) and the carrier will be described in detail.

[0115] 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.

[0116] 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 the 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.

[0117] In addition, a BWP can be defined for SL. The same SL BWP can be used in transmission and reception. For example, a transmitting UE can send a SL channel or a SL signal on a specific BWP, and a receiving UE can receive a SL channel or a SL signal on a specific BWP. In a licensed carrier, the SL BWP can be defined separately from the Uu BWP, and the SL BWP can have configuration signaling separate from the Uu BWP. For example, the UE can receive a configuration for the SL BWP from the BS / network. For example, the UE can 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 can be activated in the carrier.

[0118] 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. Figure 7 In an implementation manner, the number of BWPs is 3.

[0119] Reference 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 a resource block grid.

[0120] 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 can 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 can be the PRB distance between the lowest subcarrier within a given parameter set and point A. For example, the bandwidth can be the number of PRBs within a given parameter set.

[0121] Hereinafter, V2X or SL communication will be described.

[0122] 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.

[0123] The physical sidelink broadcast channel (PSBCH) can be a (broadcast) channel for sending default (system) information, which the UE must first know before SL signal transmission / reception. For example, the default information can 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 can be 56 bits, including a 24-bit cyclic redundancy check (CRC).

[0124] 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.

[0125] Figure 8 A process of performing V2X or SL communication based on a transmission mode by a UE 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.

[0126] 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.

[0127] 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 operations related to NR resource allocation mode 2.

[0128] Reference 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 for reporting SL HARQ feedback to the base station.

[0129] 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.

[0130] In step S810, the first UE may send a PSCCH (e.g., a sidelink control indicator (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.

[0131] Hereinafter, an example of DCI format 3_0 will be described.

[0132] DCI format 3_0 is used for scheduling NR PSCCH and NR PSSCH in one cell.

[0133] The following information is sent via DCI format 3_0 with CRC scrambled by SL-RNTI or SL-CS-RNTI:

[0134] -Resource pool index-ceiling(log 2 I) bits, where I is the number of resource pools used for transmission configured by the higher layer parameter sl-TxPoolScheduling.

[0135] - Time gap - 3 bits determined by the higher layer parameter sl-DCI-ToSL-Trans

[0136] -HARQ process number - 4 bits

[0137] - New data indicator - 1 bit

[0138] - the lowest index of the subchannel allocated to the initial transmission -ceiling(log 2 (N SL subChannel ))Bit

[0139] -SCI format 1-A field: frequency resource assignment, time resource assignment

[0140] -PSFCH-to-HARQ feedback timing indicator -ceiling(log 2 N fb_timing ) bits, where N fb_timing is the number of entries in the higher layer parameter sl-PSFCH-ToPUCCH.

[0141] -PUCCH resource indicator - 3 bits

[0142] - Configuration Index - 0 bit if the UE is not configured to monitor DCI format 3_0 with CRC scrambled by SL-CS-RNTI; otherwise 3 bits. If the UE is configured to monitor DCI format 3_0 with CRC scrambled by SL-CS-RNTI, this field is reserved for DCI format 3_0 with CRC scrambled by SL-RNTI.

[0143] - Counter sidelink assignment index - 2 bits, 2 bits if the UE is configured with pdsch-HARQ-ACK-Codebook = dynamic; 2 bits if the UE is configured with pdsch-HARQ-ACK-Codebook = semi-static

[0144] - Filling bits if necessary

[0145] Reference Figure 8 (b) in LTE transmission mode 2, LTE transmission mode 4 or NR resource allocation mode 2, the UE can 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 can be a resource pool. For example, the UE can autonomously select or schedule resources for SL transmission. For example, the UE can perform SL communication by autonomously selecting resources within the configured resource pool. For example, the UE can autonomously select resources within the selection window by performing a sensing process and a resource (re)selection process. For example, sensing can be performed in units of subchannels. For example, in step S810, the first UE that has selected resources from the resource pool by itself can send a PSCCH (e.g., a side link control indicator (SCI) or a first-level SCI) to a second UE by using the resources. In step S820, the first UE can 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 can receive a PSFCH related to the PSCCH / PSSCH from the second UE.

[0146] Reference 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.

[0147] Hereinafter, an example of SCI format 1-A will be described.

[0148] SCI format 1-A is used for scheduling PSSCH and secondary SCI on PSSCH.

[0149] The following information is sent via SCI Format 1-A:

[0150] - Priority - 3 bits

[0151] - Frequency resource assignment - When the value of the higher layer parameter sl-MaxNumPerReserve is configured as 2, the ceiling (log 2 (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 log 2 (N SL subChannel (N SL subChannel +1)(2N SL subChannel +1) / 6) bits.

[0152] - 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

[0153] -Resource reservation period - If the higher layer parameter sl-MultiReserveResource is configured, the ceiling(log 2N rsv_period ) bits, where N rsv_period is the number of entries in the higher layer parameter sl-ResourceReservePeriodList; otherwise, 0

[0154] -DMRS pattern -ceiling(log 2 N pattern ) bits, where N pattern is the number of DMRS patterns configured by the higher layer parameter sl-PSSCH-DMRS-TimePatternList

[0155] - Second level SCI format - 2 bits, as defined in Table 5

[0156] - Beta_offset indicator - 2 bits, as provided by the higher layer parameter sl-BetaOffsets2ndSCI

[0157] - Number of DMRS ports - 1 bit, as defined in Table 6

[0158] - Modulation and coding scheme - 5 bits

[0159] - 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

[0160] -PSFCH overhead indication - 1 bit if higher layer parameter sl-PSFCH-Period = 2 or 4; otherwise, 0 bit

[0161] - Reserved bits - The number of bits determined by the higher layer parameter sl-NumReservedBits, whose value is set to zero.

[0162] [Table 5]

[0163] 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

[0164] [Table 6]

[0165] Value of the Number of DMRS Ports field Antenna Port 0 1000 1 1000 and 1001

[0166] Hereinafter, an example of SCI format 2-A will be described.

[0167] 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.

[0168] The following information is sent via SCI Format 2-A:

[0169] -HARQ process number - 4 bits

[0170] - New data indicator - 1 bit

[0171] - Redundancy version - 2 bits

[0172] - Source ID - 8 bits

[0173] -Destination ID - 16 bits

[0174] -HARQ feedback enable / disable indicator - 1 bit

[0175] - Broadcast Type Indicator - 2 bits, as defined in Table 7

[0176] -CSI request - 1 bit

[0177] [Table 7]

[0178] 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

[0179] Hereinafter, an example of SCI format 2-B will be described.

[0180] 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.

[0181] The following information is sent via SCI Format 2-B:

[0182] -HARQ process number - 4 bits

[0183] - New data indicator - 1 bit

[0184] - Redundancy version - 2 bits

[0185] - Source ID - 8 bits

[0186] -Destination ID - 16 bits

[0187] -HARQ feedback enable / disable indicator - 1 bit

[0188] - Region ID - 12 digits

[0189] -Communication range requirement - 4 bits determined by the higher layer parameter sl-ZoneConfigMCR-Index

[0190] Reference 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.

[0191] Reference Figure 8 (a), in step S840, the first UE may send SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0192] Fig. 9 Three types of broadcasts are shown in accordance with embodiments of the present disclosure. 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) in FIG. 4 shows unicast type SL communication, and Fig. 9 (c) 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.

[0193] Hereinafter, a hybrid automatic repeat request (HARQ) process will be described.

[0194] 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.

[0195] 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.

[0196] (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 sending 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 sending UE.

[0197] (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 may send HARQ-NACK to the transmitting UE via 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 may send HARQ-ACK to the transmitting UE via the PSFCH.

[0198] For example, if multicast option 1 is used for SL HARQ feedback, all UEs performing multicast communication can share PSFCH resources. For example, UEs belonging to the same group can send HARQ feedback by using the same PSFCH resources.

[0199] 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.

[0200] 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.

[0201] At the same time, in the traditional unlicensed spectrum (NR-U), the communication method between the UE and the base station is supported in the unlicensed band. In addition, it is planned to support a mechanism for supporting communication between sidelink UEs in the unlicensed band in Release 18.

[0202] 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) and power spectral density (PSD).

[0203] Fig.10 Interleaved RBs based on an embodiment of the present disclosure are shown. Fig.10The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0204] Reference 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 interlace RBs given by Table 8.

[0205] [Table 8]

[0206] u M 0 10 1 5

[0207] A communication device (eg, a device, UE, vehicle, drone, etc., as proposed in various embodiments of the present disclosure) may send a signal / channel by using one or more interleaved RBs.

[0208] In the present disclosure, a channel may refer to a set of frequency domain resources in which listen-before-talk (LBT) is performed. In NR-U, a channel may refer to a LBT bandwidth of 20 MHz and may have the same meaning as an RB set. For example, an RB set may be defined in Section 7 of 3GPP TS 38.214 V17.0.0.

[0209] In the present disclosure, channel occupancy (CO) may refer to time domain / frequency domain resources obtained by a base station or UE after LBT succeeds.

[0210] In the present disclosure, channel occupation time (COT) may refer to the time domain resources obtained by the base station or UE after LBT is successful. It can be shared between the base station (or UE) and the UE (or base station) that obtains CO, and this may be referred to as COT sharing. Depending on the initiating device, this may be referred to as gNB-initiated COT or UE-initiated COT.

[0211] Hereinafter, a wireless communication system supporting an unlicensed band / shared spectrum will be described.

[0212] Fig.11 An example of a wireless communication system supporting an unlicensed frequency band based on an embodiment of the present disclosure is shown. For example, Fig.11 Unlicensed spectrum (NR-U) wireless communication systems may be included. Fig.11 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0213] In the following description, a cell operating in a licensed band (hereinafter referred to as L band) may be defined as an L cell, and a carrier of the L cell may be defined as (DL / UL / SL)LCC. In addition, a cell operating in an unlicensed band (hereinafter referred to as U band) may be defined as a U cell, and a carrier of the U cell may be defined as (DL / UL / SL)UCC. A carrier / carrier frequency of a cell may refer to an operating frequency (e.g., center frequency) of the cell. A cell / carrier (e.g., CC) is generally referred to as a cell.

[0214] When the base station and the UE send and receive signals on the LCC and UCC of the carrier aggregation, such as Fig.11 As shown in (a) of FIG. 1 , the LCC and the UCC can be configured as a primary CC (PCC) and a secondary CC (SCC), respectively. The base station and the UE can send and receive signals on one UCC or multiple carrier aggregated UCCs, such as Fig.11 As shown in (b) of . In other words, the base station and the UE can send and receive signals only on the UCC without using any LCC. For independent operation, PRACH transmission, PUCCH transmission, PUSCH transmission, SRS transmission, etc. can be supported on the UCell.

[0215] exist Fig.11 In the implementation manner, the base station can be replaced by a UE. In this case, for example, PSCCH transmission, PSSCH transmission, PSFCH transmission, S-SSB transmission, etc. can be supported on the UCell.

[0216] Unless otherwise stated, the following definitions may apply to the following terms used in this disclosure.

[0217] - Channel: A carrier or a part of a carrier consisting of a set of consecutive RBs, where a channel access procedure is performed in a shared spectrum.

[0218] - Channel Access Procedure (CAP): A procedure to evaluate channel availability based on sensing before signal transmission in order to determine whether other communication nodes are using the channel. A basic sensing unit is a unit with a duration of T sl = 9us sensing time slot. The base station or UE senses the channel during the sensing time slot duration. If the power detected within at least 4us of the sensing time slot duration is less than the energy detection threshold X thresh , then the sensing time slot duration T sl is considered idle. Otherwise, the sensing time slot duration T sl = 9us is considered busy. CAP can also be called Listen Before Talk (LBT).

[0219] - Channel occupancy: Transmission of the base station / UE on the channel after the channel access procedure.

[0220] - Channel Occupancy Time (COT): The total time that a base station / UE and any base station / UE sharing the channel occupancy can perform transmission on the channel after the base station / UE performs the channel access procedure. In the case of determining the COT, if the transmission gap is less than or equal to 25us, the gap duration can be counted into the COT. The COT can be shared by the base station and the corresponding UE for transmission.

[0221] -DL transmission burst: A collection of transmissions from a base station without any gaps greater than 16us. Transmissions from a base station separated by gaps greater than 16us are considered separate DL transmission bursts. Without sensing channel availability within a DL transmission burst, the base station may perform a transmission after a gap.

[0222] -UL or SL transmission burst: A collection of transmissions from a UE without any gaps greater than 16us. Transmissions from a UE separated by gaps greater than 16us are considered separate UL or SL transmission bursts. Without sensing channel availability within a UL or SL transmission burst, the UE may perform a transmission after a gap.

[0223] -Discovery Burst: A DL transmission burst that includes a set of signals and / or channels that are confined within a window and associated with a duty cycle. In an LTE-based system, a discovery burst may be a base station-initiated transmission that includes PSS, SSS, and cell-specific RS (CRS), and further includes a non-zero power CSI-RS. In an NR-based system, a discovery burst may be a transmission initiated by a base station that includes at least an SS / PBCH block, and further includes a CORESET of a PDCCH for scheduling a PDSCH carrying SIB1, a PDSCH carrying SIB1, and / or a non-zero power CSI-RS.

[0224] Fig.12 A method for occupying resources in an unlicensed frequency band according to an embodiment of the present disclosure is shown. Fig.12 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0225] Reference Fig.12, a communication node (e.g., base station, UE) in an unlicensed band should determine whether other communication nodes are using the channel before signal transmission. To this end, a communication node in an unlicensed band may perform a channel access procedure (CAP) to access the channel on which the transmission is performed. The channel access procedure may be performed based on sensing. For example, a communication node may perform carrier sensing (CS) before sending a signal to check whether other communication nodes are performing signal transmission. When other communication nodes are not performing signal transmission, it is said that an idle channel assessment (CCA) is confirmed. If a CCA threshold (e.g., X) is predefined or configured by a higher layer (e.g., RRC), the CCA threshold may be set to the value of the CCA threshold. Thresh ), if the detected channel energy is above the CCA threshold, the communication node may determine that the channel is busy. Otherwise, the communication node may determine that the channel is idle. If the channel is determined to be idle, the communication node may initiate signal transmission in the unlicensed band. CAP may be replaced by LBT.

[0226] Table 9 shows an example of a channel access procedure (CAP) supported in NR-U.

[0227] [Table 9]

[0228]

[0229] Referring to Table 9, LBT types or CAPs for DL / UL / SL transmission may be defined. However, Table 9 is only an example, and new types or CAPs may be defined in a similar manner. For example, Type 1 (also known as Cat-4 LBT) may be a channel access procedure based on random backoff. For example, in the case of Cat-4, the contention window may change. For example, in the case of COT sharing within a COT acquired by a base station (gNB) or UE, Type 2 may be performed.

[0230] Hereinafter, an LBT-subband (SB) (or RB set) will be described.

[0231] In a wireless communication system supporting an unlicensed band, a cell (or carrier (e.g., CC)) or BWP configured for a UE may have a broadband with a larger bandwidth (BW) than legacy LTE. However, according to regulations, the BW of a CCA that requires independent LBT operation may be restricted. A subband (SB) for performing LBT alone is defined as an LBT-SB. Then, multiple LBT-SBs may be included in one broadband cell / BWP. The set of RBs included in the LBT-SB may be configured through higher layer (e.g., RRC) signaling. Therefore, based on (i) the BW of the cell / BWP and (ii) the RB set allocation information, one or more LBT-SBs may be included in one cell / BWP.

[0232] Fig.13A case where a plurality of LBT-SBs are included in a license-free band according to an embodiment of the present disclosure is shown. Fig.13 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0233] Reference Fig.13 , a plurality of LBT-SBs may be included in the BWP of a cell (or carrier). The LBT-SB may have, for example, a 20 MHz frequency band. The LBT-SB may include a plurality of consecutive (P)RBs in the frequency domain, and may therefore be referred to as a (P)RB set. Although not shown, a guard band (GB) may be inserted between the LBT-SBs. Therefore, the BWP may be configured in the form of {LBT-SB#0 (RB set #0) + GB#0 + LBT-SB#1 (RB set #1 + GB#1) + ... + LBT-SB#(K-1) (RB set (#K-1))}. For convenience, the LBT-SB / RB index may be configured / defined in increasing order from the lowest frequency to the highest frequency.

[0234] Hereinafter, a channel access priority class (CAPC) will be described.

[0235] The CAPC of the MAC CE and radio bearers can be fixed or configured to operate in FR1:

[0236] - Fixed to the lowest priority for filling the Buffer Status Report (BSR) and the Bit Rate Recommendation MAC CE;

[0237] -For SRB0, SRB1, SRB3 and other MAC CEs, it is fixed as the highest priority;

[0238] -Configured by the base station for SRB2 and DRB.

[0239] 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.

[0240] [Table 10]

[0241]

[0242] Hereinafter, a method of transmitting a downlink signal through an unlicensed frequency band will be described. For example, the method of transmitting a downlink signal through an unlicensed frequency band may be applied to a method of transmitting a sidelink signal through an unlicensed frequency band.

[0243] The base station may perform one of the following channel access procedures (eg, CAP) for downlink signal transmission in the unlicensed band.

[0244] (1) Type 1 Downlink (DL) CAP method

[0245] In a Type 1 DL CAP, the length of the duration spanned by a sensing slot sensed as idle prior to a transmission may be random. Type 1 DL CAP may be applied to the following transmissions:

[0246] - a transmission initiated by a base station, comprising (i) a unicast PDSCH with user plane data or (ii) a unicast PDSCH with user plane data and a unicast PDCCH scheduling user plane data, or

[0247] - A transmission initiated by a base station, comprising (i) only a discovery burst or (ii) a discovery burst multiplexed with non-unicast information.

[0248] Fig.14 A CAP operation of transmitting a downlink signal through an unlicensed frequency band by a base station according to an embodiment of the present disclosure is shown. Fig.14 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0249] Reference Fig.14 , the base station can sense whether the channel is idle to sense the delay duration T d Then, if the counter N is zero, the base station may perform transmission (S134). In this case, the base station may adjust the counter N by sensing a channel for additional sensing of the time slot duration according to the following steps:

[0250] Step 1) (S120) The base station sets N to N init (N=N init ), where N init is evenly distributed between 0 and CW p Then, step 4 continues.

[0251] Step 2) (S140) If N>0 and the base station determines to decrease the counter, the base station sets N to N-1 (N=N-1).

[0252] Step 3) (S150) The base station senses the channel for the additional sensing time slot duration. If the additional sensing time slot duration is idle (Y), step 4 is continued. Otherwise (N), step 5 is continued.

[0253] Step 4) (S130) If N=0 (Y), the base station terminates CAP (S132). Otherwise (N), step 2 continues.

[0254] Step 5) (S160) The base station senses the channel until the additional delay duration T d The busy sensing time slot or the additional delay duration T d All time slots are detected as idle.

[0255] Step 6) (S170) If the additional delay duration T d If the channel is sensed to be idle during all time slots of the channel (Y), then step 4 is continued. Otherwise (N), step 5 is continued.

[0256] Table 11 shows the m applied to CAP p , minimum contention window (CW), maximum CW, maximum channel occupancy time (MCOT) and allowed CW size vary depending on the channel access priority class.

[0257] [Table 11]

[0258]

[0259] Referring to Table 11, the contention window size (CWS), maximum COT value, etc. for each CAPC may be defined. d Can be equal to T f +m p *T sl (T d =T f +m p *T sl ).

[0260] Delay duration T d Configured in the following order: Duration T f (16us)+m p The duration of the continuous sensing time slot is T sl (9us).T f The sensing time slot duration T includes the beginning of the 16us duration sl .

[0261] Satisfies the following relationship: CW min,p <=CW p <=CW max,p .CW p Available via CW p =CW min,p is configured and updated (CW size update) based on HARQ-ACK feedback (e.g., ratio of ACK or NACK) for the previous DL burst (e.g., PDSCH) before step 1. pCan be initialized to CW based on HARQ-ACK feedback for previous DL burst min,p . Alternatively, CW p Can be increased to the next higher allowed value or left as is.

[0262] (2) Type 2 Downlink (DL) CAP Method

[0263] In a Type 2 DL CAP, the length of the duration spanned by a sensing slot sensed to be idle before transmission may be determined. The Type 2 DL CAP is classified into Type 2A / 2B / 2C DL CAPs.

[0264] Type 2A DL CAP may be applied to the following transmissions. In Type 2A DL CAP, the base station may transmit the following transmissions at least during the sensing duration T short_dl = Transmission is performed immediately after sensing that the channel is idle within 25us. Here, T short_dl Including duration T f (=16us) and then the duration T f The duration of a sensing time slot is T f A sensing time slot is included at its beginning.

[0265] - A transmission initiated by a base station includes (i) only a discovery burst or (ii) a discovery burst multiplexed with non-unicast information, or

[0266] - Transmission by the base station within the shared channel occupation after a transmission interval of 25us with the UE.

[0267] Type 2B DL ​​CAP is applicable to transmissions performed by the base station during the shared channel occupancy time and after a 16us interval between transmissions by the UE. In Type 2B DL ​​CAP, the base station can f = Transmission is performed immediately after sensing that the channel is idle within 16us. f Includes a sensing slot within 9us starting from the end of the duration. Type 2C DL CAP is applicable to transmissions performed by the base station within the shared channel occupancy time and up to 16us after transmission by the UE. In Type 2C DL CAP, the base station does not perform channel sensing before performing transmission.

[0268] A method of transmitting an uplink signal through an unlicensed frequency band will be described below. For example, the method of transmitting an uplink signal through an unlicensed frequency band may be applied to a method of transmitting a sidelink signal through an unlicensed frequency band.

[0269] The UE may perform a Type 1 or Type 2 CAP for UL signal transmission in an unlicensed band. Typically, the UE may perform a CAP (e.g., Type 1 or Type 2) configured by the base station for UL signal transmission. For example, a UL grant (e.g., DCI formats 0_0 and 0_1) for scheduling PUSCH transmission may include CAP type indication information for the UE.

[0270] (1) Type 1 Uplink (UL) CAP method

[0271] In Type 1 UL CAP, the duration spanned by the sensing slots sensed as idle before transmission is random. Type 1 UL CAP may be applied to the following transmissions.

[0272] -PUSCH / SRS transmission scheduled and / or configured by the base station

[0273] - PUCCH transmissions scheduled and / or configured by the base station

[0274] - Transmissions related to the Random Access Procedure (RAP)

[0275] Fig.15 A Type 1 CAP operation performed by a UE according to an embodiment of the present disclosure to transmit an uplink signal is shown. Fig.15 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0276] Reference Fig.15 , the UE can sense whether the channel is idle to sense the delay duration T d Then, if the counter N is zero, the UE may perform transmission (S234). In this case, the UE may adjust the counter N by sensing the channel during the additional sensing slot duration according to the following steps:

[0277] Step 1) (S220) UE sets N to N init (N=N init ), where N init is evenly distributed between 0 and CW p Then, step 4 continues.

[0278] Step 2) (S240) If N>0 and the UE determines to decrease the counter, the UE sets N to N-1 (N=N-1).

[0279] Step 3) (S250) The UE senses the channel during the additional sensing time slot duration. If the additional sensing time slot duration is idle (yes), step 4 is continued. Otherwise (no), step 5 is continued.

[0280] Step 4) (S230) If N=0 (Yes), the UE terminates the CAP (S232). Otherwise (No), continue to execute step 2.

[0281] Step 5) (S260) The UE senses the channel until the additional delay duration T d A busy sensing time slot or an additional delay duration T is detected. d All time slots of are detected as being idle.

[0282] Step 6) (S270) If the additional delay duration T d If the channel is sensed to be idle during all time slot durations (yes), then step 4 is continued. Otherwise (no), step 5 is continued.

[0283] Table 12 shows the m applied to CAP p , minimum CW, maximum CW, maximum channel occupancy time (MCOT) and allowed CW size vary depending on the channel access priority category.

[0284] [Table 12]

[0285]

[0286] Referring to Table 12, the contention window size (CWS), maximum COT value, etc. for each CAPC may be defined. d Can be equal to T f +m p *T sl (T d =T f +m p *T sl ).

[0287] Delay duration T d Configure in the following order: Duration T f (16us)+m p The duration of the continuous sensing time slot is T sl (9us).T f The sensing time slot duration T includes the beginning of the 16us duration sl .

[0288] Satisfies the following relationship: CW min,p <=CW p <=CW max,p .CW p Can be by CW p =CW min,pConfiguration, and before step 1, update (CW size update) based on explicit / implicit reception response to previous UL burst (e.g., PUSCH). For example, CW size can be updated based on explicit / implicit reception response to previous UL burst. p Initialize to CW min,p . Alternatively, CW p Can be increased to the next higher allowed value or left as is.

[0289] (2) Type 2 Uplink (UL) CAP method

[0290] In a Type 2 UL CAP, the length of the duration spanned by the sensing time slots that are sensed to be idle before transmission can be determined. Type 2 UL CAP is classified into Type 2A / 2B / 2C UL CAP. In a Type 2A UL CAP, the UE can determine the length of the duration spanned by the sensing time slots that are sensed to be idle before transmission. short_dl = Transmission is performed immediately after sensing that the channel is idle within 25us. Here, T short_dl Including duration T f (=16us) and immediately after the duration T f The duration of a sensing slot after that. In Type 2A UL CAP, T f In a Type 2B UL CAP, the UE may include a sensing time slot at its beginning. f = Transmission is performed immediately after sensing that the channel is idle within 16us. In Type 2B UL CAP, T f The sensing slot within 9us starting from the end of the duration is included. In Type 2C UL CAP, the UE does not perform channel sensing before performing transmission.

[0291] For example, according to NR-U operation based on Type 1 LBT, a UE with uplink data to be sent can select a CAPC mapped to the 5QI of the data, and the UE can perform NR-U operation by applying the parameters of the corresponding CACP (e.g., minimum contention window size, maximum contention window size, mp, etc.). For example, after selecting a random value between the minimum CW and the maximum CW mapped to the CAPC, the UE can select a backoff counter (BC) between zero and a random value. In this case, for example, BC can be a positive integer less than or equal to the random value. If the channel is idle, the UE sensing the channel reduces BC by 1. If BC becomes zero and the UE is at time T d (T d =T f +m p *T sl) detects that the channel is idle within 10 seconds, the UE may attempt to send data by occupying the channel. If the UE attempting to send data detects a conflict, the UE may increase the CW size mapped to the CAPC, and the UE may reselect the BC between zero and the increased CW. The UE that successfully sends the packet may initialize the CW size (to the CW minimum value).

[0292] For example, T sl (=9 microseconds) is a basic sensing unit or sensing time slot and may include a measurement duration of at least 4 microseconds. f The first 9 microseconds of (=16 microseconds) can be configured as T sl For example, m p Can be mapped per CAPC and in T d A constant used in the calculation. For example, smaller values ​​may map to lower CACP values ​​(higher priority).

[0293] For example, according to NR-U operation based on Type 2 LBT, the UE may send data by performing Type 2 LBT (e.g., Type 2A LBT, Type 2B LBT, or Type 2C LBT) within the COT.

[0294] For example, Type 2A (also known as Cat-2 LBT (one-time LBT) or one-time LBT) can be a 25 microsecond one-time LBT. In this case, the transmission can start immediately after idle sensing within a gap of at least 20 microseconds. Type 2A can be used to initiate transmission of SSB and non-unicast DL information. That is, the UE can sense the channel within 25 microseconds within the COT, and if the channel is idle, the UE can attempt to send data by occupying the channel.

[0295] For example, type 2B may be a 16 microsecond one-time LBT. In this case, the transmission may start immediately after idle sensing within a 16 microsecond gap. That is, the UE may sense the channel within 16 microseconds within the COT, and if the channel is idle, the UE may attempt to send data by occupying the channel.

[0296] For example, in the case of Type 2C (also known as Cat-1 LBT or no LBT), LBT may not be performed. In this case, the transmission may start immediately after a gap of up to 16 microseconds, and the channel may not be sensed before the transmission. The duration of the transmission may be up to 584 microseconds. The UE may attempt to transmit after 16 microseconds without sensing, and the UE may perform the transmission within up to 584 microseconds.

[0297] In the sidelink unlicensed band, the UE may perform a channel access operation based on listen before talk (LBT). Before the UE accesses a channel in the unlicensed band, the UE should check whether the channel to be accessed is idle (e.g., a state in which the UE does not occupy the channel, a state in which the UE is able to access the corresponding channel and send data) or busy (e.g., a state in which the channel is occupied and data transmission / reception is performed on the corresponding channel, and a UE attempting to access the channel cannot send data while the channel is busy). That is, the operation in which the UE checks whether the channel is idle or busy may be referred to as a clear channel assessment (CCA), and the UE may check whether the channel is idle or busy during the CCA duration.

[0298] Fig.16 The channel access process based on the embodiment of the present disclosure is shown. Specifically, Fig.16 (a) shows an example of a dynamic channel access process (load-based equipment, LBE), Fig.16 (b) shows an example of a semi-static channel access procedure (frame-based equipment, FBE). Fig.16 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0299] Reference Fig.16 (a), if the channel is idle, the UE can compete with other UEs in the unlicensed band to immediately occupy the channel. In addition, if the UE occupies the channel, the UE can send data.

[0300] Reference Fig.16 (b), the UE may contend with other UEs on the unlicensed band for the last time (e.g., at a certain time (or start time) before the start of the next FFP) within a synchronization frame boundary (or fixed frame period (FFP)). In addition, if the UE occupies the channel within the fixed frame period (FFP), the UE may send data. The data transmission should be completed before the start of the next FFP. The UE may perform type 2 series LBT operations within the FFP. For example, within the FFP, the UE may not perform LBT based on random backoff, and the UE may sense the channel for a short period of time and perform data transmission when the channel is idle.

[0301] For example, in SL-U, the UE should first occupy a channel in the sidelink unlicensed band to send SL data. In order to occupy a channel in the sidelink unlicensed band, the UE may perform LBT (e.g., Type 1 LBT: LBT based on random backoff) to find a channel that is not occupied by a neighboring sidelink UE. For example, if a UE performing LBT finds a channel that is not occupied by other UEs, it may occupy the channel and may perform SL data transmission.

[0302] In the present disclosure, a resource allocation mode switching operation when LBT fails (e.g., fails in the process of finding an unoccupied channel) may be proposed. In the present disclosure, a UE operation when LBT fails (e.g., fails in the process of finding an unoccupied channel) may be proposed.

[0303] When sidelink data to be sent occurs (for example, when available SL data appears on the SL logical channel), a transmitting UE operating in resource allocation mode 1 can send an SR to the base station and can be allocated an authorization for BSR transmission. For example, when the transmitting UE is allocated a mode 1 authorization for BSR transmission, the transmitting UE can send the BSR using the allocated mode 1 authorization. The transmitting UE can be allocated a mode 1 authorization for sidelink data transmission by sending the BSR. However, when the transmitting UE sends an SR or the BSR fails to exceed a threshold (configured or pre-configured by the base station) due to an LBT failure of the User Universal Mobile Telecommunications System (UE-UMTS) (Uu) link, the resource allocation mode can be switched from resource allocation mode 1 to resource allocation mode 2 to enable sidelink data transmission.

[0304] For example, when sidelink data to be sent appears (e.g., when available SL data appears on the SL logical channel), the sending UE can send the sidelink data to the destination UE by including the data in the sidelink grant. For example, when the receiving UE receives a MAC PDU with HARQ feedback enabled from the sending UE (e.g., the HARQ feedback mode is set to HARQ feedback enabled), the receiving UE should send a PSFCH (e.g., HARQ feedback: ACK or NACK) to the sending UE. However, the receiving UE may not be able to send the PSFCH due to LBT failure when performing LBT for PSFCH transmission. For example, when the receiving UE does not send the PSFCH for as many times as a threshold value (e.g., configured or preconfigured by the base station) due to consecutive LBT failures reaching a threshold, the receiving UE may request the sending UE to switch the HARQ feedback mode (e.g., from HARQ feedback enabled to HARQ feedback disabled) through the SCI. For example, when the receiving UE does not send the PSFCH for as many times as the threshold value due to consecutive LBT failures reaching a threshold, the receiving UE may request the sending UE to switch the HARQ feedback mode through the MAC CE. For example, when the receiving UE does not send PSFCH for as many times as the threshold due to consecutive LBT failures reaching the threshold, the receiving UE may request the sending UE to switch the HARQ feedback mode through a PC5 RRC message. For example, when the sending UE receives a request for switching the HARQ feedback mode from the receiving UE, the sending UE may send a MAC PDU with the switched HARQ feedback mode to the receiving UE.

[0305] Fig.17An implementation of the UE switching resource allocation mode due to SL LBT failure based on an implementation of the present disclosure is shown. Fig.17 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0306] Reference Fig.17 If the sending UE fails to send an SR or BSR due to LBT failure of the Uu link exceeding a threshold (for example, configured or pre-configured by the base station. For example, the value of the threshold may also be configured per logical channel. Alternatively, the value of the threshold may be configured per CAPC), the resource allocation mode may be switched from resource allocation mode 1 to resource allocation mode 2 to perform sidelink data transmission.

[0307] Fig.18 An implementation of switching the HARQ feedback mode due to SL LBT failure based on an implementation of the present disclosure is shown. Fig.18 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0308] Reference Fig.18 , when the receiving UE does not send PSFCH due to continuous LBT failure reaching the threshold and the number of times reaches the threshold (configured or preconfigured by the base station), the receiving UE can request the sending UE to switch the HARQ feedback mode (for example, switch from HARQ feedback enable to HARQ feedback disable) through SCI. When the receiving UE does not send PSFCH due to continuous LBT failure reaching the threshold and the number of times reaches the threshold (configured or preconfigured by the base station), the receiving UE can request the sending UE to switch the HARQ feedback mode (for example, switch from HARQ feedback enable to HARQ feedback disable) through MAC CE. When the receiving UE does not send PSFCH due to continuous LBT failure reaching the threshold and the number of times reaches the threshold (configured or preconfigured by the base station), the receiving UE can request the sending UE to switch the HARQ feedback mode (for example, switch from HARQ feedback enable to HARQ feedback disable) through PC5 RRC message. For example, when the sending UE receives a request for switching the HARQ feedback mode from the receiving UE, the sending UE can send a MAC PDU with the switched HARQ feedback mode (HARQ feedback disable) to the receiving UE.

[0309] According to an embodiment of the present disclosure, unlicensed band operation in multicast NACK-only mode may be proposed as follows.

[0310] For example, when sidelink multicast data to be sent appears in the multicast NACK-only mode (for example, when available SL data appears on the SL logical channel), the sending UE can send the sidelink data to the destination UE by placing the data in the sidelink grant. When the receiving UE receives the MAC PDU from the sending UE, the receiving UE sends the PSFCH to the sending UE only when the decoding fails (for example, HARQ feedback: NACK). However, the receiving UE may not be able to send the PSFCH due to the failure of LBT when performing LBT for PSFCH transmission. In the multicast NACK-only mode, if the decoding of the PSCCH / PSSCH sent by the sending UE is successful (for example, ACK), the receiving UE may not send the PSFCH (for example, HARQ feedback: ACK). If the sending UE does not receive the PSFCH after sending the PSCCH / PSSCH, the sending UE may also determine that the corresponding PSCCH / PSSCH is sent successfully.

[0311] However, if the receiving UE performs LBT for PSFCH transmission, the receiving UE may not be able to transmit PSFCH (e.g., NACK) due to LBT failure exceeding a threshold. For example, in this case, if the transmitting UE fails to receive a certain number (threshold) or more of PSFCHs from the receiving UE, the transmitting UE may not be able to determine whether the receiving UE successfully received the PSCCH / PSSCH it transmitted without transmitting the PSFCH, or whether the receiving UE did not successfully transmit the PSFCH due to LBT failure.

[0312] Therefore, in the present disclosure, when the sending UE sends PSCCH / PSSCH but does not receive PSFCH from the receiving UE to reach a threshold (configured or pre-configured by the base station), it can be proposed to send a request through SCI to switch the HARQ feedback mode from NACK-only mode to ACK / NACK mode. In the present disclosure, when the sending UE sends PSCCH / PSSCH but does not receive PSFCH from the receiving UE to reach a threshold (configured or pre-configured by the base station), it can be proposed to send a request through MAC CE to switch the HARQ feedback mode from NACK-only mode to ACK / NACK mode. In the present disclosure, when the sending UE sends PSCCH / PSSCH but does not receive PSFCH from the receiving UE to reach a threshold (configured or pre-configured by the base station), it can be proposed to send a request through PC5 RRC message to switch the HARQ feedback mode from NACK-only mode to ACK / NACK mode.

[0313] In the present disclosure, in the groupcast NACK-only mode, if the sending UE sends PSCCH / PSSCH and fails to receive PSFCH from the receiving UE for more than a threshold value (for example, configured or pre-configured by the base station), the sending UE can indicate the switch from the NACK-only mode to the HARQ feedback disabled mode by sending an SCI, and send the SL TB with the HARQ feedback disabled MAC PDU. In the groupcast NACK-only mode, if the sending UE sends PSCCH / PSSCH and fails to receive PSFCH from the receiving UE for more than a threshold value, the sending UE can indicate the switch from the NACK-only mode to the HARQ feedback disabled mode by sending an MAC CE, and send the SL TB with the HARQ feedback disabled MAC PDU. In the groupcast NACK-only mode, if the sending UE sends PSCCH / PSSCH and fails to receive PSFCH from the receiving UE for more than a threshold value, the sending UE can indicate the switch from the NACK-only mode to the HARQ feedback disabled mode by sending a PC5 RRC message, and send the SL TB with the HARQ feedback disabled MAC PDU.

[0314] In the present disclosure, if the UE satisfies the following conditions, the UE may switch the HARQ feedback option from HARQ feedback enabled to HARQ feedback disabled, or if the UE may switch the HARQ feedback option from HARQ feedback enabled to disabled, the UE may indicate the switch to the peer UE through the SCI. This HARQ feedback option switching operation may be allowed only in units of SL TB, SLLCH or SL RB set.

[0315] - When the sending UE detects a preconfigured number of (consecutive) LBT failures

[0316] -When the CBR (Channel Busy Ratio) measurement is above a preconfigured threshold

[0317] - When the receiving UE is indicated that the RB set associated with the sidelink grant of the transmitting UE has SL (continuous) LBT failure Table 13 shows an example of SL CBR (Channel Busy Ratio) and SL RSSI (Received Signal Strength Indicator).

[0318] [Table 13]

[0319]

[0320] Referring to Table 13, the slot index may be based on the physical slot index.

[0321] In various embodiments of the present disclosure, the term “channel” may be applied by replacing it with “carrier” or “a set of resource blocks of a specific carrier” or “frequency band”.

[0322] For example, whether to apply (some) proposed methods / rules and / or related parameters (e.g., thresholds) of the present disclosure may be configured (differently or independently) for each SL channel access priority category (CAPC). For example, whether to apply (some) proposed methods / rules and / or related parameters (e.g., thresholds) of the present disclosure may be configured (differently or independently) for each SL-LBT type (e.g., type 1 LBT, type 2A LBT, type 2B LBT, type 2C LBT). For example, whether to apply (some) proposed methods / rules and / or related parameters (e.g., thresholds) of the present disclosure may be specifically (or differently or independently) configured depending on whether frame-based LBT (FBE) is applied. For example, whether to apply (some) proposed methods / rules and / or related parameters (e.g., thresholds) of the present disclosure may be specifically (or differently or independently) configured depending on whether load-based LBT (LBE) is applied.

[0323] For example, whether to apply (some) of the methods / rules and / or related parameters (e.g., thresholds) proposed in the present disclosure may be configured for each resource pool (differently or independently). For example, whether to apply (some) of the methods / rules and / or related parameters (e.g., thresholds) proposed in the present disclosure may be configured for each congestion level (differently or independently). For example, whether to apply (some) of the methods / rules and / or related parameters (e.g., thresholds) proposed in the present disclosure may be configured for each service priority (differently or independently). For example, whether to apply (some) of the methods / rules and / or related parameters (e.g., thresholds) proposed in the present disclosure may be configured for each service type (differently or independently). For example, whether to apply (some) of the methods / rules and / or related parameters (e.g., thresholds) proposed in the present disclosure may be configured for each QoS requirement (e.g., latency, reliability) (differently or independently). For example, whether to apply (some) of the methods / rules and / or related parameters (e.g., thresholds) proposed in the present disclosure may be configured for each PQI (5G QoS Identifier (5QI) for PC5) (differently or independently). For example, whether to apply (some) of the proposed methods / rules and / or related parameters (e.g., thresholds) of the present disclosure may be configured (differently or independently) for each service type (e.g., periodic generation or non-periodic generation). For example, whether to apply (some) of the proposed methods / rules and / or related parameters (e.g., thresholds) of the present disclosure may be configured (differently or independently) for each SL transmission resource allocation mode (e.g., mode 1 or mode 2). For example, whether to apply (some) of the proposed methods / rules and / or related parameters (e.g., thresholds) of the present disclosure may be configured (differently or independently) for each Tx profile (e.g., a Tx profile indicating that the service supports sidelink DRX operation or a Tx profile indicating that the service does not need to support sidelink DRX operation).

[0324] For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be specifically (or differently or independently) configured depending on whether PUCCH configuration is supported (e.g., when PUCCH resources are configured or when PUCCH resources are not configured). For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured (differently or independently) for each resource pool (e.g., a resource pool with PSFCH or a resource pool without PSFCH). For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured (differently or independently) for each side link logical channel / logical channel group (or Uu logical channel or Uu logical channel group).

[0325] For example, it is possible to configure for each resource pool (differently or independently) whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure. For example, it is possible to configure for each service / packet type (differently or independently) whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure. For example, it is possible to configure for each service / packet priority (differently or independently) whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure. For example, it is possible to configure for each QoS requirement (e.g., URLLC / EMBB service, reliability, delay) (differently or independently) whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure. For example, it is possible to configure for each PQI (differently or independently) whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure. For example, it is possible to configure for each PFI (differently or independently) whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure. For example, it is possible to configure for each play type (e.g., unicast, multicast, broadcast) (differently or independently) whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured (differently or independently) for each (resource pool) congestion level (e.g., CBR). For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured (differently or independently) for each SL HARQ feedback option (e.g., NACK feedback only, ACK / NACK feedback). For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured specifically (or differently or independently) for MAC PDU transmissions enabled for HARQ feedback. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured specifically (or differently or independently) for MAC PDU transmissions disabled for HARQ feedback. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured specifically (or differently or independently) based on whether a PUCCH-based SL HARQ feedback reporting operation is configured. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured specifically (or differently or independently) for preemption or depending on whether to perform resource reselection based on preemption. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured specifically (or differently or independently) for reassessment or depending on whether to perform resource reselection based on reassessment. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured (differently or independently) for each (L2 or L1) (source and / or destination) identifier. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured (differently or independently) for each (L2 or L1) (combination of source ID and destination ID) identifier.For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure can be configured (differently or independently) for each (L2 or L1) (a combination of a pair of source ID and destination ID and a playback type) identifier. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure can be configured (differently or independently) for each direction of a pair of source layer ID and target layer ID. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure can be configured (differently or independently) for each PC5 RRC connection / link. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure can be configured specifically (or differently or independently) depending on whether SL DRX is performed. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure can be configured specifically (or differently or independently) depending on whether SL DRX is supported. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure can be configured specifically (or differently or independently) for each SL mode type (e.g., resource allocation mode 1 or resource allocation mode 2). For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured specifically (or differently or independently) for the case of performing (non-)periodic resource reservation. For example, whether to apply the proposed rules and / or related parameter configuration values ​​of the present disclosure may be configured specifically (or differently or independently) for each Tx profile (e.g., a Tx profile indicating that the service supports sidelink DRX operation or a Tx profile indicating that the service does not need to support sidelink DRX operation).

[0326] It is proposed that the rules (and / or related parameter configuration values) proposed by the present disclosure may also be applied to millimeter wave (mmWave) SL operations.

[0327] Fig.19 A method for performing wireless communication by a first device according to an embodiment of the present disclosure is shown. Fig.19 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0328] Reference Fig.19In step S1910, the first device may obtain configuration information related to a physical sidelink feedback channel (PSFCH). In step S1920, the first device may send a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) to the second device on a physical sidelink control channel (PSCCH). In step S1930, the first device may send a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode. In step S1940, the first device may determine a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device that are skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enable mode to a HARQ feedback disable mode.

[0329] For example, the HARQ feedback mode may be switched by the first device.

[0330] For example, the HARQ feedback mode may be switched by information sent from the second device requesting to switch the HARQ feedback mode from the HARQ feedback enabled mode to the HARQ feedback disabled mode.

[0331] For example, the first device may send a medium access control (MAC) protocol data unit (PDU) to the second device based on the switched HARQ feedback mode.

[0332] For example, information requesting to switch the HARQ feedback mode may be sent via the SCI.

[0333] For example, information requesting to switch the HARQ feedback mode may be sent via a Medium Access Control (MAC) Control Element (CE).

[0334] For example, the information requesting switching of the HARQ feedback mode may be transmitted through a PC5-RRC (Radio Resource Control) message.

[0335] For example, the first device may send information related to the switched HARQ feedback mode to the second device.

[0336] For example, the information related to the switched HARQ feedback mode may be sent via at least one of an SCI, a MAC CE, or a PC5 message.

[0337] For example, based on the HARQ feedback mode being a negative acknowledgement (NACK)-only mode, the HARQ feedback mode may be switched from the NACK-only mode to an acknowledgement-NACK (ACK-NACK) mode.

[0338] For example, based on the HARQ feedback mode being the NACK-only mode, the HARQ feedback mode may be switched from the NACK-only mode to the HARQ feedback disabled mode.

[0339] For example, the first device can skip sending a scheduling request (SR) to the base station based on the failure of LBT for SR sending, based on the first device operating in resource allocation mode 1; based on the number of skipped SR transmissions reaching a threshold, the resource allocation mode of the first device can be switched from resource allocation mode 1 to resource allocation mode 2; and the first device can send data to the second device on PSSCH based on resource allocation mode 2.

[0340] For example, the first device may skip sending a buffer status report (BSR) to the base station based on the failure of LBT for sending a BSR, based on the first device operating in resource allocation mode 1; the resource allocation mode of the first device may be switched from resource allocation mode 1 to resource allocation mode 2 based on the number of skipped BSR transmissions reaching a threshold; and data may be sent to the second device on the PSSCH based on resource allocation mode 2.

[0341] The proposed method can be applied to devices according to various embodiments of the present disclosure. First, the processor 102 of the first device 100 can obtain configuration information related to a physical side link feedback channel (PSFCH). In addition, the processor 102 of the first device 100 can control the transceiver 106 to send a first side link control indicator (SCI) for scheduling a physical side link shared channel (PSSCH) and a second side link control indicator (SCI) to the second device on a physical side link control channel (PSCCH). In addition, the processor 102 of the first device 100 can control the transceiver 106 to send a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enabling mode. In addition, the processor 102 of the first device 100 can determine a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device being skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enabling mode to a HARQ feedback disabling mode.

[0342] According to an embodiment of the present disclosure, a first device configured 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 at least one processor and storing instructions. For example, the instructions are based on being executed by at least one processor so that the first device performs operations, the operations including: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); sending a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) to a second device on a physical sidelink control channel (PSCCH); sending a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode; and determining a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device that are skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enable mode to a HARQ feedback disable mode.

[0343] According to an embodiment of the present disclosure, a processing device configured to control a first device may be provided. The processing device may include: at least one processor; and at least one memory connected to at least one processor and storing instructions. For example, the instructions are executed by at least one processor to cause the first device to perform operations, the operations including: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); sending a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) to a second device on a physical sidelink control channel (PSCCH); sending a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode; and determining a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device that are skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enable mode to a HARQ feedback disable mode.

[0344] According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions may be provided. The instructions are based on being executed to cause a first device to perform an operation, the operation including: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); sending a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) to a second device on a physical sidelink control channel (PSCCH); sending a second SCI and data to the second device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enabling mode; and determining a PSFCH resource related to the PSSCH based on the configuration information. For example, based on the number of PSFCH receptions from the second device that are skipped due to a listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from a HARQ feedback enabling mode to a HARQ feedback disabling mode.

[0345] Fig. 20 A method for performing wireless communication by a second device according to an embodiment of the present disclosure is shown. Fig. 20 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0346] Reference Fig. 20 , in step S2010, the second device may obtain configuration information related to a physical sidelink feedback channel (PSFCH). In step S2020, the second device may receive a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) from the first device on a physical sidelink control channel (PSCCH). In step S2030, the second device may receive a second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enablement mode. In step S2040, the second device may determine a PSFCH resource related to the PSSCH based on the configuration information. In step S2050, the second device may skip PSFCH transmission to the first device in the PSFCH resource based on a listen-before-talk (LBT) failure for PSFCH transmission in the PSFCH resource. In step S2060, the second device transmits information related to switching the HARQ feedback mode from the HARQ feedback enabled mode to the HARQ feedback disabled mode to the first device based on the number of skipped PSFCH transmissions reaching the threshold.

[0347] The proposed method can be applied to devices according to various embodiments of the present disclosure. First, the processor 202 of the second device 200 can obtain configuration information related to a physical side link feedback channel (PSFCH). In addition, the processor 202 of the second device 200 can control the transceiver 206 to receive a first side link control indicator (SCI) for scheduling a physical side link shared channel (PSSCH) and a second side link control indicator (SCI) from the first device on a physical side link control channel (PSCCH). In addition, the processor 202 of the second device 200 can control the transceiver 206 to receive a second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode. In addition, the processor 202 of the second device 200 can determine a PSFCH resource related to the PSSCH based on the configuration information. In addition, the processor 202 of the second device 200 can skip the PSFCH transmission to the first device in the PSFCH resource based on the failure of the listen-before-talk (LBT) transmission for the PSFCH in the PSFCH resource. In addition, the processor 202 of the second device 200 may control the transceiver 206 to transmit information related to switching the HARQ feedback mode from the HARQ feedback enabled mode to the HARQ feedback disabled mode to the first device.

[0348] According to an embodiment of the present disclosure, a second device configured 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 instructions are based on being executed by at least one processor so that the second device performs operations, and the operations include: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); receiving a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) from the first device on a physical sidelink control channel (PSCCH); receiving a second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enabling mode; determining a PSFCH resource related to the PSSCH based on the configuration information; skipping PSFCH transmission to the first device in the PSFCH resource based on a listen-before-talk (LBT) failure for PSFCH transmission in the PSFCH resource; and sending information related to switching the HARQ feedback mode from a HARQ feedback enabling mode to a HARQ feedback disabling mode to the first device based on the number of skipped PSFCH transmissions reaching a threshold.

[0349] According to an embodiment of the present disclosure, a processing device configured to control a second device may be 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. For example, the instructions are based on being executed by at least one processor so that the second device performs operations, and the operations include: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); receiving a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) from the first device on a physical sidelink control channel (PSCCH); receiving a second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enabling mode; determining a PSFCH resource related to the PSSCH based on the configuration information; skipping PSFCH transmission to the first device in the PSFCH resource based on a listen-before-talk (LBT) failure for PSFCH transmission in the PSFCH resource; and sending information related to switching the HARQ feedback mode from a HARQ feedback enabling mode to a HARQ feedback disabling mode to the first device based on the number of skipped PSFCH transmissions reaching a threshold.

[0350] According to an embodiment of the present disclosure, a non-temporary computer-readable storage medium storing instructions can be provided. The instructions are executed so that the second device performs an operation, the operation including: obtaining configuration information related to a physical sidelink feedback channel (PSFCH); receiving a first sidelink control indicator (SCI) for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control indicator (SCI) from the first device on a physical sidelink control channel (PSCCH); receiving a second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enable mode; determining a PSFCH resource related to the PSSCH based on the configuration information; skipping PSFCH transmission to the first device in the PSFCH resource based on a listen-before-talk (LBT) failure for PSFCH transmission in the PSFCH resource; sending information related to switching the HARQ feedback mode from the HARQ feedback enable mode to the HARQ feedback disable mode to the first device based on the number of skipped PSFCH transmissions reaching a threshold.

[0351] Various embodiments of the present disclosure may be combined with each other.

[0352] Hereinafter, devices to which various embodiments of the present disclosure can be applied will be described.

[0353] 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 between devices (e.g., 5G).

[0354] 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.

[0355] Fig.21 A communication system 1 according to an embodiment of the present disclosure is shown. Fig. 20 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0356] Reference Fig.21 , 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, but is not limited to, 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 appliance devices, 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.

[0357] 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 as various names.

[0358] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. The 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., side link communication) with each other without passing 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., a sensor) or other wireless devices 100a to 100f.

[0359] Wireless communication / connection 150a, 150b or 150c can be established between wireless devices 100a to 100f / BS200 or BS200 / BS 200. Here, the wireless communication / connection can be established through various RATs (e.g., 5GNR) 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 can send / receive radio signals to / from each other through wireless communication / connection 150a and 150b. For example, wireless communication / connection 150a and 150b can 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 the resource allocation process can be performed based on various proposals of the present disclosure.

[0360] Fig. 22 A wireless device according to an embodiment of the present disclosure is shown. Fig. 22 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0361] Reference Fig. 22 , the first wireless device 100 and the second wireless device 200 may transmit radio signals through various RATs (e.g., LTE and NR). Herein, {the first wireless device 100 and the second wireless device 200} may correspond to Fig.21 {wireless device 100x and BS200} and / or {wireless device 100x and wireless device 100x} in.

[0362] 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 transmit 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 (one or more) memories 104 may be connected to the (one or more) processors 102, and may store various information related to the operation of the (one or more) processors 102. For example, (one or more) memory 104 may store software code including commands for executing part or all of the processing controlled by (one or more) processor 102 or for executing the description, function, process, proposal, method and / or operation flow disclosed in this document. Here, (one or more) processor 102 and (one or more) memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). (One or more) transceiver 106 may be connected to (one or more) processor 102 and send and / or receive radio signals through (one or more) antenna 108. Each transceiver 106 may include a transmitter and / or a receiver. (One or more) transceiver 106 may be used interchangeably with (one or more) radio frequency (RF) units. In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0363] 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. (One or more) memory 204 can be connected to (one or more) processors 202, and can store various information related to the operation of (one or more) processors 202. For example, (one or more) memory 204 can store software code including commands for executing part or all of the processing controlled by (one or more) processors 202 or for executing the description, function, process, proposal, method and / or operation flow disclosed in this document. Here, (one or more) processors 202 and (one or more) memory 204 can be part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). (One or more) transceivers 206 can be connected to (one or more) processors 202, and send and / or receive radio signals through (one or more) antennas 208. Each transceiver 206 may include a transmitter and / or a receiver. (One or more) transceivers 206 can be used interchangeably with (one or more) RF units. In the present disclosure, a wireless device can represent a communication modem / circuit / chip.

[0364] 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.

[0365] 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 perform 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.

[0366] 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.

[0367] 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.

[0368] Fig.23 A signal processing circuit for transmitting a signal according to an embodiment of the present disclosure is shown. Fig.23 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0369] Reference Fig.23 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.23 Operation / function, not limited to Fig. 22The processor (102, 202) and / or transceiver (106, 206) of Fig. 22 The processor (102, 202) and / or the transceiver (106, 206) are implemented Fig.23 For example, you can Fig. 22 The processor (102, 202) implements blocks 1010 to 1060. Alternatively, Fig. 22 The processor (102, 202) implements blocks 1010 to 1050 and can be implemented by Fig. 22 The transceiver (106, 206) is used to implement box 1060.

[0370] Can be through Fig.23 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).

[0371] 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.

[0372] 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.

[0373] Can Fig.23 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. Fig. 22 100, 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.

[0374] Fig.24 Another example of a wireless device according to an embodiment of the present disclosure is shown. The wireless device can be implemented in various forms according to use cases / services (see Fig.21 ). Fig.24 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0375] Reference Fig.24 , the wireless device (100, 200) may correspond to Fig. 22 The wireless device (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. 22 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. 22The 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.

[0376] The additional component 140 may be configured in various ways depending on the type of the 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.21 100a), vehicles ( Fig.21 100b-1 and 100b-2), XR devices ( Fig.21 100c), handheld device ( Fig.21 100d), household appliances ( Fig.21 100e), IoT devices ( Fig.21 100f), digital broadcast terminal, hologram device, public safety device, MTC device, medical device, fintech device (or financial device), security device, climate / environmental device, AI server / device ( Fig.21 400), BS( Fig.21 210), network nodes, etc. Depending on the use case / service, the wireless device can be used in a mobile or fixed place.

[0377] exist Fig.24In the wireless device (100, 200), all the various elements, components, units / parts and / or modules in the wireless device (100, 200) can be connected to each other through a wired interface, or at least part of them can be connected wirelessly 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 connected wirelessly 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.

[0378] Hereinafter, the implementation will be described in detail with reference to the accompanying drawings. Fig.24 .

[0379] Fig.25 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.25 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0380] Reference Fig.25 , 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.24 Frame 110 to 130 / 140.

[0381] 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.

[0382] 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.

[0383] Fig.26 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.26 The embodiments of the present invention can be combined with various embodiments of the present disclosure.

[0384] Reference Fig.26 , 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.24 Frame 110 / 130 / 140.

[0385] 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 when a destination is set, and the like.

[0386] For example, the communication unit 110 can receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d can generate an autonomous driving path and a driving plan from the acquired data. The control unit 120 can control the drive unit 140a so that the vehicle or the autonomous vehicle 100 can 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 can aperiodically / periodically obtain the latest traffic information data from the external server and obtain the surrounding traffic information data from the adjacent vehicle. In the middle of autonomous driving, the sensor unit 140c can obtain vehicle status and / or surrounding environment information. The autonomous driving unit 140d can update the autonomous driving path and driving plan based on the newly acquired data / information. The communication unit 110 can transmit information about the vehicle position, autonomous driving path and / or driving plan to the external server. The external server can predict traffic information data based on the information collected from the vehicle or autonomous vehicle using AI technology, etc., and provide the predicted traffic information data to the vehicle or autonomous vehicle.

[0387] 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 performed by a first device in a wireless communication system, the method comprising the following steps: Obtain configuration information related to a physical side link feedback channel PSFCH; Sending a first sidelink control indicator SCI for scheduling a physical sidelink shared channel PSSCH and a second sidelink control indicator SCI to the second device on a physical sidelink control channel PSCCH; sending the second SCI and data to the second device, wherein the second SCI includes information related to a hybrid automatic repeat request (HARQ) feedback enabled mode; as well as Based on the configuration information, determining a PSFCH resource associated with the PSSCH, Wherein, based on the number of PSFCH receptions from the second device skipped due to listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from the HARQ feedback enabled mode to the HARQ feedback disabled mode.

2. The method according to claim 1, in, The HARQ feedback mode is switched by the first device.

3. The method according to claim 1, in, The HARQ feedback mode is switched by information sent from the second device requesting to switch the HARQ feedback mode from the HARQ feedback enabled mode to the HARQ feedback disabled mode.

4. The method according to claim 1, further comprising the steps of: Based on the switched HARQ feedback mode, a medium access control MAC protocol data unit PDU is sent to the second device.

5. The method according to claim 3, in, The information requesting to switch the HARQ feedback mode is sent through SCI.

6. The method according to claim 3, in, The information requesting to switch the HARQ feedback mode is sent through a medium access control MAC control element CE.

7. The method according to claim 3, in, The information requesting to switch the HARQ feedback mode is sent through a PC5-Radio Resource Control RRC message.

8. The method according to claim 2, further comprising the steps of: Information related to the switched HARQ feedback mode is sent to the second device.

9. The method according to claim 8, in, The information related to the switched HARQ feedback mode is sent through at least one of SCI, MAC CE or PC5 messages.

10. The method according to claim 2, in, Based on the HARQ feedback mode being a negative acknowledgement (NACK)-only mode, the HARQ feedback mode is switched from the NACK-only mode to an ACK-NACK mode.

11. The method according to claim 2, in, Based on the HARQ feedback mode being a NACK-only mode, the HARQ feedback mode is switched from the NACK-only mode to the HARQ feedback disabled mode.

12. The method according to claim 1, Based on the first device operating in resource allocation mode 1, and based on the LBT failure for the scheduling request SR sent, skipping the SR sending to the base station; Based on the number of skipped SR transmissions reaching a threshold, switching the resource allocation mode of the first device from the resource allocation mode 1 to the resource allocation mode 2; as well as Based on the resource allocation mode 2, the data is sent to the second device on the PSSCH.

13. The method according to claim 1, Based on the first device operating in resource allocation mode 1, and based on the LBT failure for the buffer status report BSR transmission, skipping the BSR transmission to the base station; Based on the number of skipped BSR transmissions reaching a threshold, switching the resource allocation mode of the first device from the resource allocation mode 1 to the resource allocation mode 2; as well as Based on the resource allocation mode 2, the data is sent to the second device on the PSSCH.

14. A first device configured 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 being executed by the at least one processor, the operations comprising: Obtain configuration information related to a physical side link feedback channel PSFCH; Sending a first sidelink control indicator SCI for scheduling a physical sidelink shared channel PSSCH and a second sidelink control indicator SCI to the second device on a physical sidelink control channel PSCCH; sending the second SCI and data to the second device, wherein the second SCI includes information related to a hybrid automatic repeat request (HARQ) feedback enabling mode; and Based on the configuration information, determining a PSFCH resource associated with the PSSCH, Wherein, based on the number of PSFCH receptions from the second device skipped due to listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from the HARQ feedback enabled mode to the HARQ feedback disabled mode.

15. A processing device configured 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 being executed by the at least one processor, the operations comprising: Obtain configuration information related to a physical side link feedback channel PSFCH; Sending a first sidelink control indicator SCI for scheduling a physical sidelink shared channel PSSCH and a second sidelink control indicator SCI to the second device on a physical sidelink control channel PSCCH; sending the second SCI and data to the second device, wherein the second SCI includes information related to a hybrid automatic repeat request (HARQ) feedback enabling mode; and Based on the configuration information, determining a PSFCH resource associated with the PSSCH, Wherein, based on the number of PSFCH receptions from the second device skipped due to listen-before-talk (LBT) failure reaching a threshold, the HARQ feedback mode is switched from the HARQ feedback enabled mode to the HARQ feedback disabled mode.

16. A non-transitory computer-readable storage medium storing instructions, wherein the instructions, upon being executed, cause a first device to perform operations, the operations comprising: Obtain configuration information related to a physical side link feedback channel PSFCH; Sending a first sidelink control indicator SCI for scheduling a physical sidelink shared channel PSSCH and a second sidelink control indicator SCI to the second device on a physical sidelink control channel PSCCH; sending the second SCI and data to the second device, wherein the second SCI includes information related to a hybrid automatic repeat request (HARQ) feedback enabled mode; as well as Based on the configuration information, determining a PSFCH resource associated with the PSSCH, Wherein, based on the number of receptions of the PSFCH from the second device skipped due to the failure of listen-before-talk (LBT) reaching a threshold, the HARQ feedback mode is switched from the HARQ feedback enabled mode to the HARQ feedback disabled mode.

17. A method performed by a second device in a wireless communication system, the method comprising the following steps: Obtain configuration information related to a physical side link feedback channel PSFCH; receiving a first SCI for scheduling a physical sidelink shared channel PSSCH and a second sidelink control indicator SCI from a first device on a physical sidelink control channel PSCCH; receiving the second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enabled mode; Based on the configuration information, determining a PSFCH resource associated with the PSSCH; skipping the PSFCH transmission in the PSFCH resource to the first device based on a listen-before-talk (LBT) failure for the PSFCH transmission in the PSFCH resource; Based on the number of skipped PSFCH transmissions reaching a threshold, information related to switching a HARQ feedback mode from the HARQ feedback enabled mode to a HARQ feedback disabled mode is sent to the first apparatus.

18. A second device configured 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 causing the second device to perform operations upon being executed by the at least one processor, the operations comprising: Obtain configuration information related to a physical side link feedback channel PSFCH; receiving a first SCI for scheduling a physical sidelink shared channel PSSCH and a second sidelink control indicator SCI from a first device on a physical sidelink control channel PSCCH; receiving the second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enabled mode; Based on the configuration information, determining a PSFCH resource associated with the PSSCH; skipping the PSFCH transmission in the PSFCH resource to the first device based on a listen-before-talk (LBT) failure for the PSFCH transmission in the PSFCH resource; Based on the number of skipped PSFCH transmissions reaching a threshold, information related to switching a HARQ feedback mode from the HARQ feedback enabled mode to a HARQ feedback disabled mode is sent to the first apparatus.

19. A processing device configured 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 causing the second device to perform operations upon being executed by the at least one processor, the operations comprising: Obtain configuration information related to a physical side link feedback channel PSFCH; receiving a first SCI for scheduling a physical sidelink shared channel PSSCH and a second sidelink control indicator SCI from a first device on a physical sidelink control channel PSCCH; receiving the second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enabled mode; Based on the configuration information, determining a PSFCH resource associated with the PSSCH; skipping the PSFCH transmission in the PSFCH resource to the first device based on a listen-before-talk (LBT) failure for the PSFCH transmission in the PSFCH resource; Based on the number of skipped PSFCH transmissions reaching a threshold, information related to switching a HARQ feedback mode from the HARQ feedback enabled mode to a HARQ feedback disabled mode is sent to the first apparatus.

20. A non-transitory computer-readable storage medium storing instructions, wherein the instructions, upon being executed, cause a second device to perform operations, the operations comprising: Obtain configuration information related to a physical side link feedback channel PSFCH; receiving a first SCI for scheduling a physical sidelink shared channel PSSCH and a second sidelink control indicator SCI from a first device on a physical sidelink control channel PSCCH; receiving the second SCI and data from the first device, the second SCI including information related to a hybrid automatic repeat request (HARQ) feedback enabled mode; Based on the configuration information, determining a PSFCH resource associated with the PSSCH; skipping the PSFCH transmission in the PSFCH resource to the first device based on a listen-before-talk (LBT) failure for the PSFCH transmission in the PSFCH resource; Based on the number of skipped PSFCH transmissions reaching a threshold, information related to switching a HARQ feedback mode from the HARQ feedback enabled mode to a HARQ feedback disabled mode is sent to the first apparatus.

Images