Method and apparatus for processing a signal of a sidelink feedback channel in a wireless communication system

Abstract

The present disclosure relates to a pre-fifth generation (5G) or 5G communication system to be configured to support higher data rates than fourth generation (4G) communication systems such as long term evolution (LTE). An apparatus and method for performing efficient signal processing on a sidelink feedback channel in a wireless communication system is provided. The method of operating a UE in a wireless communication system includes: obtaining at least one of a source ID, a destination ID, or a cell ID; generating sidelink feedback control information (SFCI) to be sent via a sidelink feedback channel (physical sidelink feedback channel (PSFCH)); performing channel coding and scrambling on the SFCI using at least one of a source ID, a destination ID, or a cell ID; and sending the SFCI via the PSFCH.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, and more particularly to an apparatus and method for processing a signal of a sidelink feedback channel in a wireless communication system. Background Art

[0002] In order to meet the growing demand for wireless data services since the deployment of the fourth generation (4G) communication system, efforts have been made to develop improved fifth generation (5G) or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also called "beyond 4G networks" or "post-long term evolution (LTE) systems."

[0003] The 5G communication system is considered to be implemented in a higher frequency (millimeter (mm) wave) band (e.g., 60 GHz) in order to achieve a higher data rate. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-size MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technology are being discussed in the 5G communication system.

[0004] In addition, in the 5G communication system, development is being carried out for system network improvements based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, collaborative communications, coordinated multi-point (CoMP), receiving-end interference cancellation, etc.

[0005] In 5G systems, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coded modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0006] In a 5G system, a vehicle-to-everything (V2X) technology has been developed. In a V2X system where a sidelink feedback channel exists between terminals, a method and apparatus for processing a signal to effectively transmit and receive a sidelink feedback channel by a user equipment (UE) is being discussed.

[0007] The above information is presented as background information only to assist in understanding the present disclosure. No determination has been made and no assertion is made as to whether any of the above may be applicable as prior art with respect to the present disclosure. Summary of the invention

[0008] Solution to the problem

[0009] Aspects of the present disclosure are to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below. Therefore, one aspect of the present disclosure is to provide an apparatus and method for effectively processing a signal of a sidelink feedback channel in a wireless communication system.

[0010] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

[0011] According to one aspect of the present disclosure, a method for operating a UE in a wireless communication system is provided. The method includes: acquiring at least one of a source identifier (ID), a destination ID, or a cell ID; generating sidelink feedback control information (SFCI) to be sent through a sidelink feedback channel (physical sidelink feedback channel (PSFCH)); performing channel coding and scrambling on the SFCI using at least one of the source ID, the destination ID, or the cell ID; and sending the SFCI through the PSFCH.

[0012] According to another embodiment of the present disclosure, a device of a UE in a wireless communication system is provided. The device includes: at least one transceiver; and at least one processor, wherein the at least one processor is configured to obtain at least one of a source ID, a destination ID, or a cell ID, generate sidelink feedback control information (SFCI) to be sent through a sidelink feedback channel (physical sidelink feedback channel (PSFCH)), perform channel coding and scrambling on the SFCI using at least one of the source ID, the destination ID, or the cell ID, and send the SFCI through the PSFCH.

[0013] Various embodiments provide apparatus and methods for efficiently processing a signal of a sidelink feedback channel in a wireless communication system.

[0014] Other aspects, advantages, and salient features of the present disclosure will become readily apparent to those skilled in the art from the following detailed description which, in conjunction with the accompanying drawings, discloses various embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0016] Figure 1A A wireless communication system according to an embodiment of the present disclosure is shown. Figure 1B A wireless communication system according to an embodiment of the present disclosure is shown. Figure 1C A wireless communication system according to an embodiment of the present disclosure is shown, and Figure 1DA wireless communication system according to an embodiment of the present disclosure is shown;

[0017] Figure 2A A wireless communication system according to an embodiment of the present disclosure is shown, and Figure 2B A wireless communication system according to an embodiment of the present disclosure is shown;

[0018] Figure 3A shows a configuration of a base station (BS) in a wireless communication system according to an embodiment of the present disclosure;

[0019] Figure 3B The configuration of a UE in a wireless communication system according to an embodiment of the present disclosure is shown;

[0020] Figure 4 is a flowchart illustrating the operation of a UE in a wireless communication system according to an embodiment of the present disclosure;

[0021] Figure 5 A UE protocol for V2X communication in a wireless communication system according to an embodiment of the present disclosure is shown;

[0022] Figure 6 is a signal flow chart showing a V2X communication process in a wireless communication system according to an embodiment of the present disclosure;

[0023] Figure 7 The present invention shows a process of transmitting a sidelink feedback channel by a V2X UE in a wireless communication system according to an embodiment of the present disclosure;

[0024] Figure 8 The present invention shows a process of transmitting a sidelink feedback channel by a V2X UE in a wireless communication system according to an embodiment of the present disclosure;

[0025] Fig. 9 The present invention shows a process of transmitting a sidelink feedback channel by a V2X UE in a wireless communication system according to an embodiment of the present disclosure;

[0026] Fig.10 A sidelink resource through which a V2X UE performs V2X communication in a wireless communication system according to an embodiment of the present disclosure is shown;

[0027] Fig.11 A multiplexing scheme of a sidelink control channel, a sidelink data channel, and a sidelink feedback channel within a sidelink resource in a wireless communication system according to an embodiment of the present disclosure is shown;

[0028] Fig.12 The structure of a sidelink feedback channel in a wireless communication system according to an embodiment of the present disclosure is shown; and

[0029] Fig.13The structure of a sidelink feedback channel in a wireless communication system according to an embodiment of the present disclosure is shown.

[0030] Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. DETAILED DESCRIPTION

[0031] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist understanding, but these details are to be regarded as merely exemplary. Therefore, those of ordinary skill in the art will recognize that various changes and modifications may be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, for the sake of clarity and brevity, descriptions of well-known functions and configurations may be omitted.

[0032] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Therefore, it should be clear to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustrative purposes only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0033] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0034] For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted or schematically shown. In addition, the size of each element does not fully reflect the actual size. In the accompanying drawings, the same or corresponding elements are given the same reference numerals.

[0035] By referring to the embodiments described below in conjunction with the accompanying drawings, the advantages and features of the present disclosure and their implementation will be clear. However, the present disclosure is not limited to the embodiments set forth below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose the present disclosure and inform the technicians in the field of the scope of the present disclosure, and the present disclosure is limited only by the scope of the attached claims. Throughout the specification, the same or similar reference numerals designate the same or similar elements.

[0036] Here, it will be understood that each box in the flowchart illustration and the combination of boxes in the flowchart illustration can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate means for implementing the functions specified in one or more flow boxes. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can guide the computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-usable or computer-readable memory generate products including means for indicating the functions specified in one or more flow boxes. Computer program instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operations to be performed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide operations for implementing the functions specified in one or more flow boxes.

[0037] In addition, each frame in the flowchart diagram may represent a module, segment or a part of code including one or more executable instructions for implementing the specified (one or more) logical functions. It should also be noted that in some alternative implementations, the functions indicated in the frame may not occur in order. For example, depending on the functions involved, two frames shown in succession may actually be performed substantially simultaneously, or these frames may sometimes be performed in reverse order.

[0038] As used herein, "unit" refers to a software element or hardware element such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) that performs a predetermined function. However, the meaning of "unit" is not always limited to software or hardware. "Unit" can be constructed to be either stored on an addressable storage medium, or executed on one or more processors. Therefore, "unit" includes, for example, a software element, an object-oriented software element, a class element or a task element, a process, a function, an attribute, a procedure, a subroutine, a segment of a program code, a driver, a firmware, a microcode, a circuit, a data, a database, a data structure, a table, an array and a parameter. The element and function provided by "unit" can be either combined into a smaller number of elements or "units", or divided into a larger number of elements or "units". In addition, element and "unit" or can be implemented as one or more central processing units (CPUs) in a reproduction device or a secure multimedia card. In addition, "unit" in an embodiment can include one or more processors.

[0039] The detailed description of the embodiments is mainly based on the new radio (NR) access network (or new RAN) and the packet core (5G system, 5G core network or next generation (NG) core), that is, the core network of the fifth generation (5G) mobile communication standard specified by the third generation partnership project (3GPP) corresponding to the mobile communication standardization organization, but the main subject matter of the present disclosure may be other communication systems with similar technical backgrounds that are slightly modified without departing from the scope of the present disclosure that can be determined by technicians in this field.

[0040] In the 5G system, a network data collection and analysis function (NWDAF) can be defined, i.e., a network function for analyzing and providing data collected through the 5G network to support network automation. The NWDAF can collect information from the 5G network, store and analyze the information, and provide the results to a non-specific network function (NF), and the analysis results can be used independently by each NF.

[0041] For ease of description, the present disclosure may use terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard, the 5G New Radio (NR) standard, or similar system standards. However, the present disclosure is not limited to the terms or names and may be equally applied to systems conforming to other standards.

[0042] For the convenience of description, the terms used to identify access nodes, the terms referring to network entities, the terms referring to messages, the terms referring to interfaces between network entities, and the terms referring to various identification information in the following description are used. Therefore, the present disclosure is not limited to the terms used in the present disclosure, and other terms referring to entities with equivalent technical meanings may be used.

[0043] In order to meet the increased demand for wireless data traffic after the commercialization of 4G communication systems, efforts have been made to develop improved 5G communication systems (new radio (NR)). 5G communication systems have been designed to use resources in millimeter wave bands (e.g., 28GHz bands) to achieve high data transmission rates. In 5G communication systems, technologies such as beamforming, massive multiple input multiple output (MIMO), full-size MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas are being discussed to reduce propagation path losses in millimeter wave bands and increase propagation transmission distances. In addition, unlike LTE, 5G communication systems support various subcarrier spacings such as 30kHz, 60kHz, and 120kHz including 15 kilohertz (kHz), and the physical control channel uses polarity coding and the physical data channel uses low-density parity check (LDPC) coding. In addition, as a waveform for uplink transmission, not only discrete Fourier transform extended orthogonal frequency division multiplexing (DFT-S-OFDM) is used, but also cyclic prefix-based orthogonal frequency division multiplexing (CP-OFDM) is used. Although resources for hybrid automatic repeat request (HARQ) retransmission in units of transport blocks (TBs) are allocated in LTE, resources for HARQ retransmission based on a code block group (CBG) including multiple code blocks (CBs) may be additionally allocated in 5G.

[0044] In addition, technologies such as evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, vehicle-to-everything networks (V2X networks), cooperative communications, coordinated multi-point (CoMP), and reception interference cancellation have been developed to improve system networks in 5G communication systems.

[0045] In addition, the Internet has evolved from a human-centered connection network, in which people generate and consume information, to the Internet of Things (IoT), in which distributed components such as things exchange and process information. Internet of Everything (IoE) technology has emerged, which combines big data processing technology connected with cloud servers and the like with IoT technology. In order to realize IoT, research is being conducted on technical factors such as sensing technology, wired / wireless communication, and network infrastructure, and service interface technology and security technology are required, so technologies such as sensor networks, machine-to-machine (M2M), machine-type communication (MTC), etc. are used for connection between things. In the IoT environment, by collecting and analyzing data generated in connected things, smart Internet technology (IT) services can be provided, thereby creating new value for people's lives. Through the convergence between information technology (IT) and various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart cars, connected cars, smart grids, healthcare, smart appliances, or high-tech medical services.

[0046] Therefore, various attempts have been made to apply 5G communication to IoT networks. For example, beamforming, MIMO, and array antenna schemes are used to implement 5G communication technologies such as sensor networks, machine-to-machine (M2M) communications, and machine-type communications (MTC). The application of cloud RAN as a big data processing technology is an example of the integration of 5G technology and IoT technology. As described above, a plurality of services can be provided to a user in a communication system, and in order to provide a plurality of services to a user, a method for providing each service within the same time interval according to its characteristics and a device using the method are required. Various services provided by the 5G communication system are being studied, one of which is a service that meets the requirements of low latency and high reliability.

[0047] In the case of vehicle communication, standardization competition for LTE-based V2X has been launched in 3GPP Rel-14 and Rel-15 based on the device-to-device (D2D) communication structure, and development research on 5G New Radio (NR)-based V2X is currently underway. In NR V2X, unicast communication, groupcast communication, multicast communication, and broadcast communication between UEs will be supported. In addition, the goal of NR V2X is to provide deeper services such as scheduling, advanced driving, extended sensors, and remote driving, while the goal of LTE V2X is to send and receive basic safety information required for driving a vehicle.

[0048] The NR V2X transmitting UE may transmit sidelink control information and data information to the NR V2X receiving UE. The NR V2X receiving UE receiving the sidelink control information and data information may transmit an ACK or NACK for the sidelink data information received by the NR V2X receiving UE to the NR V2X transmitting UE. The ACK / NACK information may be referred to as sidelink feedback control information (SFCI). The SFCI may be transmitted through a sidelink feedback channel (physical sidelink feedback channel (PSFCH)) of the physical layer.

[0049] At the same time, the NR V2X transmitting UE may transmit a sidelink reference signal so that the NR V2X receiving UE may obtain information about the sidelink channel state. The sidelink reference signal may be a demodulation reference signal (DMRS) used by the NR V2X receiving UE to estimate the channel or a channel state information reference signal (CSI-RS) used to obtain channel state information. When using CSI-RS, the CSI-RS may be sent using frequency / time / code resources different from the DMRS. The NR V2X receiving UE that obtains the sidelink channel state information through the DMRS or CSI-RS sent by the NR V2X transmitting UE may report the sidelink channel state information to the NR V2X transmitting UE. At this time, the CSI report information may correspond to the above-mentioned SFCI and may be sent through the sidelink feedback channel.

[0050] In another example, HARQ-ACK / NACK information and CSI report information may be multiplexed and simultaneously transmitted through a sidelink feedback channel.

[0051] In order to support the above scenario, an embodiment of the present specification is proposed, and the goal of this embodiment is to provide a method and device for NR V2X UE to send and receive sidelink feedback channels.

[0052] Figure 1A A wireless communication system according to an embodiment of the present disclosure is shown. Figure 1B A wireless communication system according to an embodiment of the present disclosure is shown. Figure 1C A wireless communication system according to an embodiment of the present disclosure is shown, and Figure 1D A wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Figure 1A , Figure 1B , Figure 1C and Figure 1D An example of a system for describing an embodiment is shown.

[0053] Reference Figure 1A , Figure 1B , Figure 1C and Figure 1D, base stations (SB) 101 and 102 are network infrastructures for providing wireless access to terminals 121, 122, 123, 124, 125, 126, and 127. BSs 101 and 102 have coverage areas defined as predetermined geographical areas based on the distance to which a signal can be transmitted. In addition to "base station", BSs 101 or 102 may be referred to as "access points (APs)", "eNodeBs (eNBs)", "fifth generation (5G) nodes", "next generation NodeBs (gNBs)", "wireless points", "transmission / reception points (TRPs)", "roadside units (RSUs)", or other terms with equivalent technical meanings.

[0054] In the present specification, the terminals 121, 122, 123, 124, 125, 126, and 127 are devices for users to use, and communicate with the BSs 101 and 102 through radio channels. Depending on the situation, at least one of the terminals 121, 122, 123, 124, 125, 126, and 127 may operate without any involvement of the user. For example, at least one of the terminals 121, 122, 123, 124, 125, 126, and 127 may be a device that performs machine type communication (MTC) and may not be carried by the user. In addition to the "terminal", the UEs 121, 122, 123, 124, 125, 126, and 127 may be referred to as "user equipment", "mobile station", "user station", "remote terminal", "wireless terminal", "user device", or other terms with equivalent technical meanings.

[0055] Figure 1A A situation is shown where all V2X terminals (that is, UE-1 121 and UE-2 122) are located within the coverage area 103 of BS 101.

[0056] The V2X terminals 121 and 122 can all receive data and control information from the BS 101 through a downlink (DL), or send data and control information to the BS through an uplink (UL). The data and control information can be data and control information for V2X communication. Alternatively, the data and control information can be data and control information for common cellular communication. The V2X terminal can send and receive data and control information for V2X communication through a sidelink (SL).

[0057] Figure 1B A case where UE-1 121 among the V2X terminals 121 and 122 is located within the coverage area 103 of the BS 101 and UE-2 102 is located outside the coverage area 103 of the BS 101 is shown. Figure 1B An example of may be an example related to a partial coverage area.

[0058] UE-1 121 located within the coverage area of ​​BS 101 may receive data and control information from BS 101 through a downlink (DL) and transmit data and control information to BS 101 through an uplink (UL).

[0059] UE-2 122 located outside the coverage area 103 of BS 101 cannot receive data or control information from BS 101 through a downlink, and cannot transmit data or control information to BS 101 through an uplink.

[0060] UE-2 122 may transmit / receive data and control information for V2X communication to / from UE-1 121 via a sidelink.

[0061] Figure 1C A situation is shown where the V2X terminals 121 and 122 are located outside the coverage area 103 of the BS 101.

[0062] Therefore, UE-1 121 and UE-2 122 cannot receive data or control information from BS 101 through a downlink, and cannot transmit data or control information to BS 101 through an uplink.

[0063] UE-1 121 and UE-2 122 may transmit / receive data and control information for V2X communication through a sidelink.

[0064] Figure 1D The diagram shows a scenario where terminals 121 and 122 located in different cells 103 and 104 perform V2X communication. Specifically, Figure 1D A state in which a V2X transmitting UE and a V2X receiving UE access different BSs (that is, a radio resource control (RRC) connection state) or a state in which a terminal camps on a BS (that is, an RRC connection release state (RRC idle state)) is shown. UE-1 121 may be a V2X transmitting UE, and UE-2 122 may be a V2X receiving UE. Alternatively, UE-1 121 may be a V2X receiving UE, and UE-2 122 may be a V2X transmitting UE. UE-1 121 may receive a V2X dedicated system information block (SIB) from a BS 101 accessed by UE-1 121 or on which UE-1 121 camps, and UE-2 122 may receive a V2X dedicated SIB from another BS 102 accessed by UE-2 122 or on which UE-2 122 camps. Information about the V2X dedicated SIB received by UE-1 121 and information about the V2X dedicated SIB received by UE-2 122 may be different from each other. Therefore, for V2X communication between terminals 121 and 122 located in different cells 103 and 104, unified information is required.

[0065] although Figures 1A to 1D For the convenience of description, a V2X system including two terminals (UE-1 and UE-2) is shown, but the present disclosure is not limited thereto. The downlink and uplink between the BS and the V2X UE may be referred to as a Uu interface, and the sidelink between the V2X UEs may be referred to as a PC5 interface. Therefore, these terms may be used interchangeably in the present disclosure.

[0066] Meanwhile, in the present disclosure, a UE may be a vehicle supporting vehicle-to-vehicle (V2V) communication, a mobile phone of a vehicle or a pedestrian (that is, a smart phone supporting vehicle-to-pedestrian (V2P) communication), a vehicle supporting vehicle-to-network (V2N) communication, or a vehicle supporting vehicle-to-infrastructure (V2I) communication. In the present disclosure, a terminal may be a roadside unit (RSU) having a UE function, an RSU having a BS function, or an RSU having some of the BS functions and some of the UE functions.

[0067] In the present disclosure, the predefined BS is a BS that supports both V2X communication and common cellular communication or a BS that supports only V2X communication. The BS may be a 5G BS (gNB), a 4G BS (eNB), or an RSU. Therefore, unless otherwise specifically mentioned, the BS and the RSU may be the same concept and thus may be used interchangeably.

[0068] Figure 2A A wireless communication system according to an embodiment of the present disclosure is shown, and Figure 2B A wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Figure 2A and Figure 2B An example of a V2X communication method performed through a side link is shown.

[0069] Reference Figure 2A , the sending UE and the receiving UE can communicate in a one-to-one manner, which can be called unicast communication.

[0070] Reference Figure 2B , the sending UE and the receiving UE can communicate in a one-to-many manner, which can be called groupcast or multicast communication.

[0071] Reference Figure 2B, UE-1 121, UE-2 122, and UE-3 123 form group A 128 to perform groupcast communication, and UE-4 124, UE-5 125, UE-6 126, and UE-7 127 may form group B 129 to perform groupcast communication. Each UE may perform groupcast communication only within the group to which the UE belongs, and may perform unicast, multicast, or broadcast communication with terminals located in different groups. Although Figure 2B It is shown that two groups 128 and 128 are formed, but the present disclosure is not necessarily limited to these two groups.

[0072] In addition, despite the Figure 2A and Figure 2B Although not shown in FIG. 1 , the V2X UE may perform broadcast communication. Broadcast communication is communication whereby all V2X UEs receive data and control information sent by a V2X transmitting UE via a sidelink. For example, when Figure 2B Assuming that UE-1 121 is a transmitting UE for broadcasting, all UEs (that is, UE-2 122, UE-3 123, UE-4 124, UE-5 125, UE-6 126 and UE-7 127) can receive data and control information transmitted by UE-1 121.

[0073] Figure 3A A configuration of a BS in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 3A The configuration shown in may be understood as the configuration of BS 101 or 102. The term "~ unit" or "~ device" used hereinafter may refer to a unit that processes at least one function or operation and may be implemented in hardware, software, or a combination of hardware and software.

[0074] Reference Figure 3A , the BS 101 or 102 includes a wireless communication unit 310, a backhaul communication unit 320, a storage unit 330, and a controller 340.

[0075] The wireless communication unit 310 performs functions for sending and receiving signals through a wireless channel. For example, the wireless communication unit 310 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when data is transmitted, the wireless communication unit 310 generates complex symbols by encoding and modulating the transmitted bit stream. When data is received, the wireless communication unit 310 recovers the received bit stream by demodulating and decoding the baseband signal.

[0076] The wireless communication unit 310 up-converts the baseband signal into a radio frequency (RF) band signal and transmits the signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For this purpose, the wireless communication unit 310 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. In addition, the wireless communication unit 310 may include multiple transmission / reception paths. In addition, the wireless communication unit 310 may include at least one antenna array composed of multiple antenna units.

[0077] On the hardware side, the wireless communication unit 310 may include a digital unit and an analog unit, and the analog unit may include a plurality of sub-units according to operating power, operating frequency, etc. The digital unit may be implemented by, for example, a digital signal processor (DSP).

[0078] The wireless communication unit 310 transmits and receives signals as described above. Therefore, all or some of the wireless communication units 310 may be referred to as "transmitters", "receivers" or "transceivers". In addition, transmission and reception performed through the radio channel described in the following description may be understood to mean that the above-mentioned processing is performed by the wireless communication unit 310.

[0079] The backhaul communication unit 320 provides an interface for performing communication with other nodes within the network. That is, the backhaul communication unit 320 converts a bit stream sent from a base station to another node (e.g., another access node, another base station, a higher node, or a core network) into a physical signal, and converts a physical signal received from another node into a bit stream.

[0080] The storage unit 330 stores data such as basic programs, applications, or configuration information for the operation of the BS 101 or 102. The storage unit 330 may be configured as a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, the storage unit 330 provides the stored data in response to a request from the controller 340.

[0081] The controller 340 controls the overall operation of the BS 101 or 102. For example, the controller 340 sends and receives signals through the wireless communication unit 310 or the backhaul communication unit 320. In addition, the controller 340 records data in the storage unit 330, and reads the recorded data. The controller 340 can perform the functions of the required protocol stack according to the communication standard. According to another implementation, the protocol stack can be included in the wireless communication unit 310. For this purpose, the controller 340 may include at least one processor. According to various embodiments, the controller 340 may be functionally connected to the wireless communication unit 310, the backhaul communication unit 320 and the storage unit 330 of the BS 101 or 102, and may be configured to perform the operating method of the BS 101 or 102.

[0082] Figure 3B The configuration of a UE in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 3B It may be understood as a configuration of UE 121, 122, 123, 124, 125, 126 or 127. The term "~ unit" or "~ device" used hereinafter may refer to a unit that processes at least one function or operation and may be implemented in hardware, software, or a combination of hardware and software.

[0083] refer to Figure 3B , UE 121 , 122 , 123 , 124 , 125 , 126 or 127 includes a communication unit 350 , a storage unit 360 and a controller 370 .

[0084] The communication unit 350 performs a function for transmitting / receiving a signal through a wireless channel. For example, the communication unit 350 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when data is transmitted, the communication unit 350 generates complex symbols by encoding and modulating the transmitted bit stream. When data is received, the communication unit 350 recovers the received bit stream by demodulating and decoding the baseband signal. In addition, the communication unit 350 up-converts the baseband signal to an RF band signal, transmits the RF band signal through an antenna, and then down-converts the RF band signal received by the antenna to a baseband signal. For example, the communication unit 350 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0085] In addition, the communication unit 350 may include multiple transmit / receive paths. In addition, the communication unit 350 may include at least one antenna array consisting of multiple antenna units. On the hardware side, the communication unit 350 may include digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFIC)). The digital circuits and analog circuits may be implemented as a single package. The communication unit 350 may include multiple RF chains. The communication unit 350 may perform beamforming.

[0086] In addition, the communication unit 350 may include multiple communication modules for supporting a variety of different radio access technologies. For example, different radio access technologies may include Bluetooth Low Energy (BLE), Wireless Fidelity (Wi-Fi), Wi-Fi Gigabyte (WiGig), and cellular networks, such as Long Term Evolution (LTE) or 5G NR. In addition, different frequency bands may include ultra-high frequency (SHF) (e.g., a frequency band from 3.5 GHz to 5 GHz) and millimeter (mm) waves (e.g., a frequency band of 60 GHz).

[0087] The communication unit 350 transmits and receives signals as described above. Therefore, all or some of the communication units 350 may be referred to as "transmitters", "receivers" or "transceivers". In addition, transmission and reception performed through the radio channel described in the following description may be understood to mean that the above-mentioned processing is performed by the communication unit 350.

[0088] The storage unit 360 stores data such as basic programs, applications, and configuration information for the operation of the UE 121, 122, 123, 124, 125, 126, or 127. The storage unit 360 may be configured as a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, the storage unit 360 provides the stored data in response to a request from the controller 370.

[0089] The controller 370 controls the overall operation of UE 121, 122, 123, 124, 125, 126 or 127. For example, the controller 370 sends and receives signals through the communication unit 310. In addition, the controller 370 records data in the storage unit 360, and reads the recorded data. The controller 370 can perform the protocol stack functions required by the communication standard. For this purpose, the controller 370 may include at least one processor or microprocessor, or may act as a processor. In addition, a part of the communication unit 350 or the controller 370 may be referred to as a communication processor (CP). The controller 370 may be functionally connected to the communication unit 350 and the storage unit 360 of the UE 121, 122, 123, 124, 125, 126 or 127, and may be configured to perform the operation method of the UE 121, 122, 123, 124, 125, 126 or 127 according to various embodiments.

[0090] Figure 4 is a flowchart illustrating an operation of a UE in a wireless communication system according to an embodiment of the present disclosure.

[0091] Reference Figure 4 , in operation S401, the UE acquires at least one of a transmitter ID (source identifier), a destination ID, and a cell ID. The destination ID may be one of a unicast destination ID, a multicast destination ID, and a broadcast destination ID. According to an embodiment of the present disclosure, the UE may acquire information about the transmitter ID and the destination ID through a service search process performed in an application layer. According to an embodiment of the present disclosure, when the UE and another UE performing V2X communication with the UE are both within the coverage area of ​​the same BS, the UE and the other UE may acquire a cell ID from the corresponding BS. According to an embodiment of the present disclosure, when the UE and another UE performing V2X communication with the UE are both outside the coverage area of ​​the BS, the UE and the other UE may acquire a predefined cell ID or a preconfigured cell ID. The predefined cell ID or the preconfigured cell ID may be a specific cell ID that the UE and the other UE already know before the V2X communication. According to an embodiment of the present disclosure, when the UE and another UE performing V2X communication with the UE are within the coverage areas of different BSs, the UE and the other UE may acquire a predefined cell ID and a preconfigured cell ID. At this time, information about the cell IDs of different BSs may be exchanged.

[0092] In operation S402, the UE generates sidelink feedback control information (SFCI) to be transmitted through a sidelink feedback channel (physical sidelink feedback channel (PSFCH)). According to an embodiment of the present disclosure, the UE may generate SFCI to be transmitted through the PSFCH according to a configuration or instruction from another UE or BS performing V2X communication with the UE. For example, the UE may receive a configuration or instruction indicating whether only NACK information should be transmitted or each of ACK and NACK information should be transmitted.

[0093] In operation S403, the UE performs channel coding and scrambling on the SFCI based on at least one of the transmitter ID, the destination ID, and the cell ID. According to an embodiment of the present disclosure, a scrambling sequence generator for scrambling may be initialized based on at least one of the transmitter ID, the destination ID, and the cell ID. According to an embodiment of the present disclosure, the PSFCH may include one or more orthogonal frequency division multiplexing (OFDM) symbols. According to an embodiment of the present disclosure, the PSFCH may have one or more formats, and the corresponding formats may use different signal processing methods. According to an embodiment of the present disclosure, the PSFCH may have one or more formats with different signal processing methods according to the number of bits of the SFCI, and may include one or more OFDM symbols. According to an embodiment of the present disclosure, the PSFCH may alternately include OFDM symbols in which a demodulation reference signal (DMRS) is present and OFDM symbols in which the DMRS is not present. According to an embodiment of the present disclosure, in the OFDM symbols included in the PSFCH, the positions of resource elements (REs) for transmitting the DMRS are different.

[0094] In operation S404, the UE transmits SFCI through the PSFCH. According to an embodiment of the present disclosure, the transmission of SFCI may be performed through one of unicast, groupcast, and broadcast schemes. At this time, the resources of the PSFCH may include resources distinguished not only in the time or / and frequency domains, but also resources distinguished using codes such as scrambling codes or orthogonal cover codes, and resources distinguished using different sequences and cyclic shifts applied to the sequences.

[0095] Figure 5 The UE protocol for V2X communication in a wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Figure 5 An example of a UE protocol for V2X communication according to various embodiments is shown.

[0096] Despite Figure 5Although not shown in the figure, the application layer of UE-A 501 and UE-B 503 may perform service discovery. The service discovery may include discovery indicating a V2X communication scheme (that is, a communication scheme to be performed by each UE among unicast, groupcast, and broadcast communication schemes).

[0097] Reference Figure 5 , it can be assumed that UE-A 501 and UE-B 503 recognize that a unicast communication scheme will be performed via a service discovery process performed on the application layer. The NR V2X UE can obtain information about a transmitter ID (source identifier) ​​and a destination ID (identifier) ​​for NR V2X communication through the service discovery process.

[0098] When the service discovery process is complete, you can Figure 5 The PC5 signaling protocol layer shown performs a direct link establishment process between UEs. At this time, security setting information for direct communication between UEs can be exchanged.

[0099] When the direct link setup is complete, you can Figure 5 The PC5 RRC configuration process between UEs is performed in the PC5 RRC layer of UE-A 501. At this time, UE capability information of UE-A 501 and UE-B 503 can be exchanged, and access stratum (AS) layer parameter information for unicast communication can be exchanged.

[0100] When the PC5 Radio Resource Control (RRC) configuration procedure is completed, UE-A 501 and UE-B 503 may perform unicast communication.

[0101] Although unicast communication is described as an example, multicast communication may be applied. Figure 5 When UE-C, not shown in the figure, performs multicast communication, service discovery between UE-A 501 and UE-B 503, direct link establishment and PC5 RRC configuration procedures can be performed between UE-B 503 and UE-C and between UE-A 501 and UE-C.

[0102] Figure 6 is a signal flow chart showing a V2X communication process in a wireless communication system according to an embodiment of the present disclosure. Specifically, Figure 6 An example of a V2X communication process according to an embodiment of the present disclosure is shown.

[0103] Reference Figure 6In operation S601, the BS 601 may configure parameters for V2X communication in the V2X UEs 603 and 605 through system information. For example, the BS 601 may configure information about a resource pool through which V2X communication may be performed in its own cell. A resource pool may be referred to as a transmission resource pool for V2X transmission or a reception resource pool for V2X reception. The V2X UEs 603 and 605 may receive configuration of information about one or more resource pools from the BS 601. The BS 601 may configure unicast, multicast, and broadcast communications to be performed in different resource pools through system information. For example, resource pool 1 may be used for unicast communication, resource pool 2 may be used for multicast communication, and resource pool 3 may be used for broadcast communication. In another example, the BS 601 may configure unicast, multicast, and broadcast communications to be performed within the same resource pool. The resource pool information configured by the BS 601 may include at least one of the following information.

[0104] 1. Information on the time axis about the resource pool through which the physical sidelink control channel (PSCCH) and the physical sidelink shared channel (PSSCH) can be sent: specifically including the time slot index for sending PSCCH and PSSCH or the time slot index for sending PSCCH and PSSCH and the symbol index within the corresponding time slot.

[0105] 2. Information about frequency resources of the sidelink feedback channel: refers to information on the frequency axis about the resource pool through which PSCCH and PSSCH can be sent, and specifically includes the index of the resource blocks included in the resource pool or the index of the subchannel including two or more resource blocks.

[0106] 3. Information on whether sidelink HARQ-ACK is operating may be included in the resource pool configuration information.

[0107] (1) In case of sidelink HARA-ACK operation, at least one of the following information may be included.

[0108] (1-1) Maximum number of retransmissions

[0109] (1-2) HARQ-ACK timing: indicates the time from the time point when the V2X receiving UE 605 receives the sidelink control information and data information from the V2X transmitting UE 603 ​​to the time point when the V2X receiving UE 605 transmits HARQ-ACK / NACK information intended for it to the V2X transmitting UE 603. The time unit may be a time slot or one or more OFDM symbols.

[0110] (1-3) Physical Sidelink Feedback Channel (PSFCH) Format: When operating two or more PSFCH formats, one PSFCH format may be used to send 1-bit or 2-bit HARQ-ACK / NACK information. Another PSFCH format may be used to send 3-bit or more HARQ-ACK / NACK information. In addition, when HARQ-ACK / NACK information is sent through PSFCH, each of ACK information and NACK information may be sent through PSFCH. When the PSSCH sent from the NR V2X sending UE is successfully decoded, the NR V2X receiving UE may send ACK through PSFCH. When the decoding fails, the NR V2X receiving UE may send NACK through PSFCH. In another example, the NR V2X receiving UE may not send ACK when the PSSCH sent from the NR V2X sending UE is successfully decoded, and may send NACK through PSFCH only when the decoding fails.

[0111] (1-4) A set of time / frequency / code resources included in the PSFCH: In the case of time resources, it includes the index of the time slot or symbol in which the PSFCH is transmitted and the period. In the case of frequency resources, the set of time / frequency / code resources may include the start and end points of a subchannel (or the start and length of a frequency resource), which subchannel includes a frequency resource block (RB) or two or more consecutive blocks in which the PSFCH is transmitted.

[0112] 4. Information about whether blind retransmission is running may be included in the resource pool configuration information.

[0113] (1) Unlike HARQ-ACK / NACK-based retransmission, blind retransmission can be repeated transmission by the NR transmitting UE when the NR transmitting UE does not receive feedback information of ACK or NACK from the NR receiving UE. When blind retransmission is running, the number of blind retransmissions can be included in the resource pool information. For example, when the number of blind retransmissions is 4, the NR transmitting UE can always send the same information four times when sending PSCCH / PSSCH to the NR receiving UE. At this time, the redundancy version (RV) value can be included in the sidelink control information (SCI) sent through the PSCCH.

[0114] 5. Information about the DMRS pattern that can be used for PSSCH sent in the corresponding resource pool.

[0115] (1) The DMRS pattern that can be used for PSSCH can change according to the UE speed. For example, when the speed is fast, it is necessary to increase the number of OFDM symbols used for DMRS transmission on the time axis in order to improve the accuracy of channel estimation. When the UE speed is slow, the accuracy of channel estimation can be guaranteed even if a small number of DMRS symbols are used, so that it is necessary to reduce the number of OFDM symbols used for DMRS transmission on the time axis in order to reduce DMRS overhead. Therefore, the information about the resource pool may include information about the DMRS pattern that can be used for the corresponding resource pool. At this time, two or more DMRS patterns can be configured in one resource pool, and the NR V2X transmitting UE 603 ​​can select and use one DMRS pattern from the configured DMRS patterns according to its own speed. The NR V2X transmitting UE 603 ​​can send information about the DMRS pattern for selection by the NR V2X transmitting UE to the NR V2X receiving UE 605 through the SCI of the PSCCH. The NR V2X receiving UE 605 can receive information through demodulation and decoding processing, obtain DMRS pattern information, estimate the channel for PSSCH, and obtain sidelink data information.

[0116] 6. Information on whether the sidelink channel state information reference signal (CSI-RS) is operational.

[0117] (1) In the case of sidelink CSI-RS operation, at least one of the following information may be included.

[0118] (1-1) CSI-RS transmission start time point: indicates the start time point at which the V2X transmitting UE 603 ​​should transmit the CSI-RS to the V2X receiving UE 605. The start time point may refer to the index of the time slot in which the CSI-RS is transmitted, the index of the symbol in which the CSI-RS is transmitted, or the index of both the time slot and the symbol.

[0119] (1-2) CSI reporting timing: indicates the time from the time point when the V2X receiving UE 605 receives the CSI-RS from the V2X transmitting UE 603 ​​(that is, the index of the received time slot or the index of the symbol within the received time slot) to the time point when the V2X receiving UE sends a CSI report to the V2X transmitting UE (that is, the index of the time slot for sending the CSI report or the index of the symbol within the sent time slot). The time unit may be a time slot or one or more OFDM symbols.

[0120] 7. Parameters for controlling sidelink transmit power

[0121] Although the above information is included in the configuration of the resource pool for V2X communication, the present disclosure is not limited thereto. For example, the information may be configured in the V2X transmitting UE 603 ​​or the V2X receiving UE 605 independently of the configuration of the resource pool.

[0122] Reference Figure 6 , when the V2X transmitting UE 603 ​​has data to be transmitted to the V2X receiving UE 605 in operation S602, the V2X transmitting UE 603 ​​may issue a request for a sidelink resource to be transmitted to the V2X receiving UE 605 to the BS 601 through a scheduling request (SR) or / and a buffer status report (BSR). The BS 601 receiving the BSR may recognize that the V2X transmitting UE 603 ​​has data for sidelink transmission, and determine resources required for the sidelink transmission based on the BSR.

[0123] In operation S604, the BS 601 may send a sidelink scheduling grant including at least one of resource information for sidelink control information (SCI) transmission, resource information for sidelink data transmission, and resource information for sidelink feedback information to the V2X transmission UE 603. The sidelink scheduling grant is information for permitting dynamic scheduling in the sidelink, and may be downlink control information (DCI) transmitted through a physical downlink control channel (PDCCH). The sidelink scheduling grant may include information indicating a bandwidth part (BWP) in which the sidelink transmission is performed, a carrier indicator field (CIF) or a carrier frequency indicator for the sidelink transmission when the BS 601 is an NR BS, and may include only the CIF when the BS is an LTE BS. In addition, the sidelink scheduling grant may also include feedback information for the sidelink data, that is, resource allocation related information of the PSFCH in which ACK / NACK information is transmitted. When the sidelink transmission corresponds to a groupcast, the resource allocation information may include information for allocating multiple PSFCH resources to multiple UEs in the group. The information related to resource allocation of the feedback information may be information indicating at least one of a plurality of feedback information resource candidate sets configured through higher layer signaling.

[0124] In operation S605, the V2X transmitting UE 603 ​​receiving the sidelink scheduling grant transmits SCI for scheduling sidelink data according to the sidelink scheduling grant to the V2X receiving UE 605 through a physical sidelink control channel (PSCCH), and transmits the sidelink data through a physical sidelink shared channel (PSSCH). The SCI may include resource allocation information for sidelink data transmission, modulation and coding scheme (MCS) information applied to the sidelink data, group destination ID information, transmitter ID (source ID) information, unicast destination ID information, power control information for controlling sidelink power, timing advance (TA) information, DMRS configuration information for sidelink transmission, information related to repeated transmission of a data packet (e.g., information on the number of repeated transmissions of a data packet, information on resource allocation when the data packet is repeatedly transmitted), a redundancy version (RV), and at least one of a HARQ process ID. The SCI may also include feedback information for the sidelink data, that is, information indicating a resource through which ACK / NACK information is transmitted.

[0125] The V2X receiving UE 605 receiving the SCI receives the sidelink data. Thereafter, in operation S606, the V2X receiving UE 605 sends ACK / NACK information indicating whether the decoding of the sidelink data is successful or failed to the V2X sending UE 603 ​​through the physical sidelink feedback channel (PSFCH). The transmission of the sidelink feedback information can be applied to unicast transmission or multicast transmission, but does not exclude the case of broadcast transmission. When the sidelink transmission corresponds to the multicast transmission, the corresponding UE receiving the multicast data can send feedback information through different PSFCH resources. Alternatively, the corresponding UE receiving the multicast data can send feedback information through the same PSFCH resource, in which case only NACK information can be fed back. For example, in the case of ACK, the UE receiving the data does not perform feedback. At this time, the PSFCH resources may include resources that are distinguished not only in the time or / and frequency domains, but also resources that are distinguished using codes such as scrambling codes or orthogonal cover codes and resources that are distinguished using different sequences and cyclic shifts applied to the sequences.

[0126] Figure 6 1 shows a scenario in which the V2X transmitting UE 603 ​​configures an uplink connection with the BS 601 (that is, an RRC connected state), and both the V2X transmitting UE 603 ​​and the V2X receiving UE 605 exist within the coverage area of ​​the BS 601. Figure 6, when the V2X transmitting UE 603 ​​has not configured an uplink connection with the BS 601 (that is, is in the RRC idle state), the V2X transmitting UE 603 ​​may perform a random access procedure for configuring an uplink connection with the BS 601. Figure 6 , but in a scenario where the V2X transmitting UE 603 ​​exists within the coverage area of ​​the BS 601 and the V2X receiving UE 605 exists outside the coverage area of ​​the BS 601, the V2X receiving UE 605 may receive the configuration of the information for V2X communication in advance. At the same time, the V2X transmitting UE 603 ​​may receive the configuration of the information for V2X communication from the BS 601, such as Figure 6 . When both the V2X transmitting UE 603 ​​and the V2X receiving UE 605 are outside the coverage area of ​​the BS 601, the V2X transmitting UE 603 ​​and the V2X receiving UE 605 may receive and use the configuration of the information of the V2X communication in advance. At this time, receiving the configuration in advance may be interpreted as using the value included in the UE when the UE is issued. Alternatively, it may refer to the most recently acquired information when the V2X transmitting UE 603 ​​or the V2X receiving UE 605 has visited the BS 601 and has previously acquired the information about the V2X communication through the RRC configuration or has acquired the information about the V2X communication through the system information of the BS 601.

[0127] Despite Figure 6 603 before sending the SR / BSR to the BS 601. Figure 5 The process shown in completes the service discovery, direct link establishment process and PC5 RRC configuration with the V2X receiving UE 605.

[0128] Figure 7 The process of V2X UE sending a sidelink feedback channel in a wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Figure 7 An example of a signal processing method by which a V2X UE transmits a sidelink feedback channel according to an embodiment is shown.

[0129] Reference Figure 7 In operation S701, the NR V2X receiving UE may obtain parameters for sending a sidelink feedback channel through at least one of the following methods.

[0130] 1. When the NR V2X receiving UE configures an RRC connection with the BS within the coverage area of ​​the BS, the NR V2X receiving UE may receive configuration of parameters for sidelink feedback channel transmission from the BS through UE-specific RRC. At this time, the BS is the BS that configures the RRC connection and may be an NR BS or an LTE BS.

[0131] 2. When the NR V2X receiving UE does not configure an RRC connection with the BS within the coverage area of ​​the BS (that is, in the RRC idle state), the NR V2X receiving UE may receive configuration of parameters for sidelink feedback channel transmission from the BS through system information (system information block (SIB)).

[0132] 3. In another example, the NR V2X receiving UE may receive the configuration of the parameters for the sidelink feedback channel transmission from the NR V2X transmitting UE that desires to perform unicast or multicast communication with the NR V2X receiving UE. At this time, the NR V2X transmitting UE may transmit the parameters for the sidelink feedback channel transmission to the NR V2X receiving UE via the sidelink control channel.

[0133] Information about parameters used for sidelink feedback channel transmission may be included in Figure 6 PSFCH related information described in and one or more of the following information.

[0134] 4. Information about the time resources of the sidelink feedback channel: including information about the resource pool on the time axis in which the PSFCH can be sent, specifically, the index of the time slot in which the PSFCH is sent or the index of the time slot in which the PSFCH is sent and the index of the symbol in the corresponding time slot.

[0135] (1) The NR V2X receiving UE may receive information about a time slot in which a PSFCH may be transmitted from a BS or an NR V2X transmitting UE in the form of a bitmap. For example, an NR V2X UE receiving the bitmap information "1001" may transmit a PSFCH in a time slot indicated by "1", but may not transmit a PSFCH in a time slot indicated by "0". At this time, the BS or the NR V2X transmitting UE may transmit information at a starting point, that is, transmit information at a starting time slot to which the corresponding bitmap is applied. For example, the information about the starting point may inform an offset based on a system frame number (SFN) 0 of the BS, and the offset may be a starting point to which the bitmap may be applied. When there is no BS, that is, when the NR V2X receiving UE exists outside the BS coverage area, the starting point may be indicated, that is, an offset of the bitmap may be applied based on a direct frame number (DFN) 0 transmitted through a physical sidelink broadcast channel (PSBCH) by a UE providing a sidelink synchronization signal. In another example, information about the time slot in which the PSFCH can be transmitted can be interpreted based on the time slot in which the NR V2X UE receives the PSCCH or PSSCH. For example, the BS or the NR V2X transmitting UE can inform the NR V2X receiving UE of the transmission of the PSFCH after the "Kth time slot" from the time slot in which the PSCCH or PSSCH is received.

[0136] (2) When information about a symbol index is included in the PSFCH time resource information, the index of the symbol at which the PSFCH starts and the length of the symbol, that is, the number of symbols occupied by the PSFCH may be explicitly included. In another example, when the length of the symbol varies according to the format of the PSFCH, information about the time slot in which the PSFCH is transmitted and information about the PSFCH format may be transmitted. For example, it may be assumed that PSFCH format 1 includes one orthogonal frequency division multiplexing (OFDM) symbol and PSFCH format 2 includes two OFDM symbols. At this time, the NR V2X receiving UE may obtain information about the time resource of the PSFCH to be transmitted by the NR V2X receiving UE through the index of the time slot in which the PSFCH is transmitted and the starting point and format of the PSFCH symbol in the time slot. In another example, the position of the PSFCH in the time slot may be fixed. For example, when one time slot consists of 14 OFDM symbols, the PSFCH may always be located at the 12th OFDM symbol in the time slot only when the PSFCH is in operation. In this case, information about the time resources of the PSFCH within the time slot can be obtained by information about the number of OFDM symbols included in the PSFCH. In another example, when the number of OFDM symbols is defined according to the PSFCH format and the PSFCH exists at a fixed position within the time slot as described above, information about the time resources of the PSFCH can be obtained using only the PSFCH format information.

[0137] 5. Information about frequency resources of the sidelink feedback channel: refers to information on the frequency axis about the resource pool through which the PSFCH can be sent, and specifically includes the index of the resource blocks included in the resource pool or the index of the subchannel including two or more resource blocks.

[0138] (1) The NR V2X receiving UE may receive information about resource blocks in which the PSFCH may be transmitted from the BS or the NR V2X transmitting UE in the form of a bitmap. For example, the NR V2X UE receiving the bitmap information "1001" may transmit the PSFCH in the RB or subchannel indicated by "1", and may not transmit the PSFCH in the RB or subchannel indicated by "0". The BS or the NR V2X transmitting UE may transmit the information at the starting point, that is, transmit the information at the starting RB or starting subchannel to which the corresponding bitmap is applied. For example, the information about the starting point may inform an offset based on an RB with the lowest index (that is, index 0) in the system bandwidth operated by the BS, and the offset may be the starting point to which the bitmap may be applied. When there is no BS, that is, when the NR V2X receiving UE exists outside the BS coverage area, the starting point may be indicated, that is, the offset of the bitmap may be applied based on the lowest index in the V2X communication bandwidth transmitted by the UE providing the sidelink synchronization signal through the physical sidelink broadcast channel (PSBCH).

[0139] (2) In another example, information about the RB or subchannel in which the PSFCH can be transmitted can be interpreted based on the RB or subchannel in which the NR V2X UE receives the PSCCH or PSSCH. For example, the BS or the NR V2X transmitting UE can inform the NR V2X receiving UE of the transmission of the PSFCH after the "Nth RB or subchannel" from the RB or subchannel in which the PSCCH or PSSCH is received. Information about the number of RBs or subchannels in which the PSFCH is actually transmitted can also be transmitted together with the information about the starting point. The NR V2X UE receiving the information can transmit the PSFCH based on the information about the starting point of the frequency resources used for PSFCH transmission and the number of RBs or the number of subchannels.

[0140] (3) In another example, the NR V2X receiving UE may know in advance the transmission of the PSFCH in the "Nth RB or subchannel" based on the RB or subchannel in which the PSCCH or PSSCH is received. At this time, the information that the UE knows in advance may be a value included in the UE when the UE is issued. Alternatively, the information that the UE knows in advance may be the most recently acquired information when the UE has accessed the BS and has acquired information about frequency resources through RRC information or when the UE has acquired information about frequency resources through system information of the BS without accessing the BS.

[0141] 6. Type of SFCI sent through PSFCH: The NR V2X receiving UE may receive information about the type of SFCI sent through PSFCH from the BS or the NR V2X transmitting UE. The SFCI may include HARQ-ACK information or CSI information.

[0142] (1) When HARQ-ACK information is transmitted through PSFCH, that is, when SFCI is HARQ-ACK information, the NR V2X receiving UE may receive configuration or indication of information indicating whether ACK information and NACK information should be transmitted separately or only NACK information should be transmitted from the BS or the NR V2X transmitting UE. The configuration or indication method may be one of the following methods.

[0143] (1-1) It is possible to explicitly configure or indicate whether the NR V2X receiving UE should send only NACK information or send ACK information and NACK information separately. For example, the configuration or indication may be performed when the NR V2X transmitting UE and the NR V2X receiving UE perform PC5 RRC configuration. When the NR V2X transmitting UE and the NR V2X receiving UE are present in the coverage area of ​​the BS, the NR V2X receiving UE may obtain information indicating whether only NACK information should be sent or ACK information and NACK information should be sent separately through the RRC configuration of the BS or the system information of the BS. In addition, the NR V2X transmitting UE may analyze the SFCI sent from the NR V2X UE through the PSFCH by acquiring the information. For example, the information may be included in the information about the resource pool through which the PSFCH may be sent or the PSCCH / PSSCH may be sent. For example, resource pool 1 may be configured to send only HARQ NACK, and resource pool 2 may be configured to send both HARQ-ACK and NACK. In another example, the NR V2X transmitting UE may send an indication to the NR V2X receiving UE using sidelink control information (SCI) sent over the PSCCH, indicating whether the NR V2X receiving UE should send only NACK information or send both ACK information and NACK information separately.

[0144] (1-2) It may be implicitly configured or indicated whether the NR V2X receiving UE should send only NACK information or send ACK information and NACK information separately. For example, the corresponding information may be mapped to the format of the PSFCH sent by the NR V2X receiving UE. For example, PFSCH format 1 may indicate the transmission of only HARQ-NACK, and PSFCH format 2 may indicate the transmission of HARQ-ACK and HARQ-NACK separately. The BS or NR V2X sending UE may send information about the PSFCH format to be used by the NR V2X receiving UE, and the PSFCH UE receiving the information may determine whether to send only NACK information or send ACK information and NACK information separately according to the corresponding format. In another example, the BS or NR V2X sending UE may send information about the resources of the PSFCH to be used by the NR V2X receiving UE, and the NR V2X receiving UE receiving the information may determine whether to send only NACK information or send ACK information and NACK information separately according to the corresponding format. Specifically, when the NR V2X receiving UE should only send NACK information, the BS or the NR V2X transmitting UE may allocate one PSFCH resource to the NR V2X receiving UE in the time, frequency, or code domain. When the NR V2X receiving UE should send ACK information and NACK information respectively, the BS or the NR V2X transmitting UE may allocate two PSFCH resources to the NR V2X receiving UE in the time, frequency, or code domain. The case where two PSFCH resources are allocated in the code domain may be a case where the resources in the time axis and the frequency axis are the same but different sequences are used. Alternatively, the resources in the time axis and the frequency axis are the same and the same type of sequence is used, but different cyclic shift (CS) values ​​are used. For example, the ACK information may be CS=0, and the NACK information may be CS=6. Similarly, the case where one PSFCH resource is allocated in the code domain may be a case where the resources in the time axis and the frequency axis are the same, and the same type of sequence and the same CS value are used.

[0145] (1-3) When there are two or more NR V2X receiving UEs, that is, in groupcast communication, each NR V2X receiving UE may operate in a manner similar to the above. For example, the BS or the NR V2X transmitting UE may send a configuration or indication to each NR V2X receiving UE indicating whether only NACK information should be sent or both ACK information and NACK information should be sent. Such configuration or indication information may be sent explicitly or implicitly as described above. The operation of the NR V2X receiving UE may be the same within the group. For example, according to the configuration or indication of the BS or the NR V2X transmitting UE, all NR V2X receiving UEs in the group may send only NACK information or send both ACK information and NACK information. When only NACK information is sent, all NR V2X receiving UEs in the group may share at least the PSFCH resources on the time / frequency / code axis. When both ACK information and NACK information should be sent, the NR V2X receiving UE can orthogonally use the PSFCH resources on the time / frequency / code axis according to the configuration or indication of the BS or the NR V2X transmitting UE (that is, the PSFCH resources on the time / frequency / code axis used by NR V2X receiving UE 1 and NR V2X receiving UE 2 are different), or two or more NR V2X receiving UEs can share at least one of the PSFCH resources on the time / frequency / code axis.

[0146] (2) The CSI information may be at least one of a channel quality indicator (CQI), a rank indicator (RI), and a precoder matrix indicator (PMI). The CSI information may be included in the SFCI, but may be transmitted to the NR V2X transmitting UE through a sidelink data channel (physical sidelink shared channel (PSSCH)) instead of the PSFCH. If the NR V2X receiving UE has sidelink data information to be transmitted to the NR V2X transmitting UE when the CSI information is transmitted to the corresponding NR V2X transmitting UE through the PSSCH, the CSI information and the sidelink data information may be multiplexed and transmitted through the PSSCH in the same time slot. In another example, if the NR V2X receiving UE has sidelink data information to be transmitted to the NR V2X transmitting UE when the CSI information is transmitted to the corresponding NR V2X transmitting UE through the PSSCH, only one of the CSI information and the sidelink data information may be transmitted. For example, the NR V2X receiving UE may discard the transmission of the sidelink data information and transmit only the CSI information. Alternatively, the NR V2X receiving UE may discard the CSI information and may only send the sidelink data information.

[0147] (3) When CSI information is sent through PSFCH, the CSI information can be multiplexed with HARQ-ACK information and sent simultaneously.

[0148] In operation S702, the NR V2X receiving UE may generate SFCI information to be sent through the PSFCH according to the configuration or instruction of the BS or the NR V2X sending UE.

[0149] 1. For example, the NR V2X receiving UE may receive a configuration or indication of information indicating whether HARQ-ACK / NACK information of one transport block (TB) is to be transmitted or HARQ-ACK / NACK information of two or more TBs is to be transmitted from the BS or the NR V2X transmitting UE. When HARQ-ACK / NACK information of two or more TBs should be transmitted, a configuration or indication of information indicating the number of TBs for which HARQ-ACK / NACK information should be transmitted may be received.

[0150] 2. In operation S701, as described above, a configuration or indication of information indicating whether only NACK information should be sent or ACK information and NACK information should be sent separately may be received.

[0151] 3. In another example, an indication or configuration of information indicating whether HARQ-ACK / NACK information is sent in units of code block groups (CBGs) rather than in units of TBs may be received. In this case, information about the number of CBGs may be configured or indicated.

[0152] 4. When CSI information is transmitted through PSFCH, information about SFCI included in CSI may be configured or indicated. For example, information indicating whether all CQI, RI, and PMI are transmitted or only CQI other than RI and PMI is transmitted may be configured or indicated.

[0153] 5. Although the example describes that all configurations or instructions are performed by the BS or the NR V2X transmitting UE, the present disclosure is not limited thereto. For example, the NR V2X receiving UE may receive in advance the configuration of the SFCI information transmitted through the PSFCH. The pre-configured configuration may be a value included in the UE when the UE is issued. Alternatively, the pre-configured configuration may be the most recently acquired information when the UE has accessed the BS and has acquired the corresponding information through the RRC information or when the UE has acquired the corresponding information through the system information of the BS without accessing the BS.

[0154] In operation S703, the NR V2X receiving UE may encode the channel using the SFCI information (that is, the bit sequence) generated in operation S702. At this time, different channel coding schemes may be applied according to the length of the generated bit sequence.

[0155] 1. When the length of the bit sequence included in the SFCI information is 3 bits or more and 11 bits or less (32, 0), a Reed-Muller (RM) code may be used. At this time, 0 may be the SFCI information as the input of the RM code, and 32 may be the output of the RM code. For example, 3 to 11 bits are encoded as 32 bits.

[0156] 2. When the length of the bit sequence included in the SFCI information is 12 bits or more, polar coding can be used. At this time, when the SFCI is 12 bits or more and 19 bits or less, for example, when it is assumed that the SFCI is [x] bits, a 6-bit cyclic redundancy check (CRC) can be added to the [x]-bit SFCI (that is, [x] + 6 bits), and then channel coding can be performed. When the SFCI is 20 bits or more, for example, when it is assumed that the SFCI is [y] bits, an 11-bit CRC can be added to the [y]-bit SFCI (that is, [y] + 11 bits), and then channel coding can be performed.

[0157] In operation S704, the NR V2X receiving UE may scramble the bit sequence obtained through the channel coding in operation S703.

[0158] 1. When it is assumed that an M-bit sequence is generated by channel coding in operation 703, the M-bit sequence may be expressed as b(0), b(1), ..., b(M-1). At this time, a scrambling sequence c(i) may be added to b(0), b(1), ..., b(M-1), a modulo 2 operation may be performed, and b(i) may be generated as shown in Formula 1.

[0159] Modulo 2, where i = 0, 1, ..., M-1 ... Formula 1

[0160] In Formula 1, the scrambling sequence c(i) is a pseudo-random sequence and may correspond to a golden sequence having a length of 31. The scrambling sequence generator of c(i) used in Formula 1 may be initialized by Formula 2.

[0161] c inlt =A·2 α +B·2 β +γ...Formula 2

[0162] In Formula 2, there may be various combinations depending on α, β, γ, A and B, and α, β, γ, A and B may be determined by at least one of a transmitter ID (source ID), a destination ID and a cell ID. It may be assumed that the transmission ID (source ID) includes [s] bits, the destination ID includes [d] bits, and the cell ID includes [c] bits. When both the NR V2X transmitting UE and the NR V2X receiving UE exist in the coverage area of ​​the same BS, the NR V2X transmitting UE and the NR V2X receiving UE may acquire the cell ID used in Formula 2 from the corresponding BS. In another example, the NR V2X transmitting UE and the NR V2X receiving UE may always use a fixed cell ID of Formula 2. For example, cell ID = 510 or cell ID = 1024. At the same time, the NR V2X transmitting UE may obtain the cell ID used in Formula 2 by referring to Figure 5 At least one of the service discovery process, direct link establishment process, or PC5 RRC configuration process described for unicast or multicast communication obtains the destination ID information of the UE that the NR V2X transmitting UE expects to transmit from a higher layer (e.g., an application layer or an L2 layer). In addition, the NR V2X transmitting UE can obtain information about the transmitter ID (source ID) of the NR V2X transmitting UE from its higher layer. Formula 2 may include the case where both A and B are 0 and one of A and B is 0. In Formula 2, β may be affected by γ, and α may be affected by B and β. For example, as described above, when cell ID=1024 is used as γ, γ can be changed to 210 through binary conversion. In this case, β=11. When it is assumed that B=1, α=12. However, this is merely an example and is not limited to this. For example, similar to the example, even if cell ID=1024 is used as γ, β=14.

[0163] 2. The NR V2X transmitting UE may send information about a transmitter ID (source ID) or a destination ID for use by the NR V2X transmitting UE to the NR V2X receiving UE through at least one of the following methods.

[0164] (1) Method 1) The [s] bit of the transmitter ID (source ID) and the [d] bit of the destination ID are transmitted via the PSCCH

[0165] (1-1) The V2X receiving UE that acquires information about the transmitter ID (source ID) and the destination ID transmitted through the SCI of the PSCCH can determine whether the destination ID included in the SCI corresponds to the V2X receiving UE itself. When the destination ID corresponds to the V2X receiving UE itself, that is, when the destination ID transmitted by the V2X transmitting UE is the same as the destination ID received from the upper layer of the V2X receiving UE, the V2X receiving UE can decode the PSSCH through the resource allocation information of the PSSCH included in the SCI. When the V2X receiving UE successfully decodes the PSSCH, the V2X receiving UE can send ACK information to the V2X transmitting UE through the PSFCH. When the V2X receiving UE fails to decode the PSSCH, the V2X receiving UE can send NACK information to the V2X transmitting UE through the PSFCH. The PSFCH can be scrambled by initializing the scrambling sequence generator as shown in Formula 2 based on at least one of the transmitter ID (source ID), the destination ID, and the cell ID acquired by the V2X UE through method 1) and the above method.

[0166] (1-2) When the destination ID transmitted through the SCI in the above example does not correspond to the V2X receiving UE, the V2X receiving UE may delete the corresponding SCI from its own buffer and may not decode the PSSCH.

[0167] (2) Method 2) Send [s] bits of the transmitter ID (source ID) and some bits of the destination ID via PSCCH

[0168] (2-1) The remaining bits of the destination ID may be transmitted using a MAC header transmitted through a PSSCH or a media access control protocol data unit (MAC PDU). For example, the most significant bit (MSB) or the least significant bit (LSB) [d1] of the [d] bits of the destination ID may be transmitted through a PSCCH, and the remaining [d2] bits may be transmitted using a MAC header transmitted through a PSSCH or a MAC PDU ([d1]+[d2]=[d]).

[0169] (2-2) The V2X receiving UE that obtains information about the transmitter ID (source ID) and the destination ID transmitted through the SCI of the PSCCH can determine whether the [d1] bit of the destination ID included in the SCI corresponds to the V2X receiving UE itself. When the destination ID corresponds to the V2X receiving UE itself, the V2X receiving UE can decode the PSSCH through the resource allocation information of the PSSCH included in the SCI. When the V2X receiving UE successfully decodes the PSSCH, the V2X receiving UE can generate a [d] bit destination ID using the remaining bits (that is, [d1] bits) of the destination ID transmitted through the PSSCH and the [d2] bits of the destination ID received through the SCI. The V2X receiving UE can compare the generated destination ID with the destination ID received from the upper layer of the V2X receiving UE, and finally identify whether the corresponding PSSCH is the sidelink data to be received by the V2X receiving UE. When, through the final identification, it is identified that the corresponding PSSCH is the sidelink data to be received by the V2X receiving UE, the V2X receiving UE can transmit the decoding result to the upper layer. When it is identified through final recognition that the corresponding PSSCH is not the sidelink data to be received by the V2X receiving UE, the V2X receiving UE may delete the decoding result from its own buffer without transmitting it to a higher layer.

[0170] (2-3) At the same time, the V2X receiving UE that successfully decodes the PSSCH and recognizes that the corresponding PSSCH is the sidelink data that the V2X receiving UE will receive can send ACK information to the V2X sending UE through the PSFCH. When the V2X receiving UE fails to decode the PSSCH, the V2X receiving UE can send NACK information to the V2X sending UE through the PSFCH. At this time, the V2X receiving UE can initialize the scrambling sequence generator and perform scrambling as shown in Formula 2 based on at least one of the transmitter ID (source ID), destination ID, and cell ID obtained by method 2) and the above method.

[0171] (2-4) When the destination ID transmitted through the SCI in the above example does not correspond to the V2X receiving UE, the V2X receiving UE may delete the corresponding SCI from its own buffer and may not decode the PSSCH.

[0172] (3) Method 3) Some bits of the transmitter ID (source ID) and [d] bits of the destination ID are transmitted via PSCCH

[0173] (3-1) The remaining bits of the transmitter ID may be transmitted using a medium access control (MAC) header transmitted via a PSSCH or a MAC protocol data unit (PDU). For example, the most significant bit (MSB) or least significant bit (LSB) [s1] bit of the [s] bit of the transmitter ID (source ID) may be transmitted via a PSCCH, and the remaining [s2] bits may be transmitted using a MAC header transmitted via a PSSCH or a MAC PDU ([s1]+[s2]=[d]).

[0174] (3-2) The V2X receiving UE that obtains information about the transmitter ID (source ID) and the destination ID transmitted through the SCI of the PSCCH can determine whether the destination ID included in the SCI corresponds to the V2X receiving UE itself. When the destination ID corresponds to the V2X receiving UE itself, that is, when the destination ID transmitted by the V2X transmitting UE is the same as the destination ID received from the upper layer of the V2X receiving UE, the V2X receiving UE can decode the PSSCH through the resource allocation information of the PSSCH included in the SCI. When the V2X receiving UE successfully decodes the PSSCH, the V2X receiving UE can send ACK information to the V2X transmitting UE through the PSFCH. When the V2X receiving UE fails to decode the PSSCH, the V2X receiving UE can send NACK information to the V2X transmitting UE through the PSFCH. The PSFCH can be scrambled by initializing the scrambling sequence generator as shown in Formula 2 based on at least one of the transmitter ID (source ID), the destination ID, and the cell ID obtained by the V2X UE through method 3) and the above method.

[0175] (3-3) When the destination ID transmitted through the SCI in the above example does not correspond to the V2X receiving UE, the V2X receiving UE may delete the corresponding SCI from its own buffer and may not decode the PSSCH.

[0176] (4) Method 4) Some bits of the transmitter ID (source ID) and some bits of the destination ID are transmitted through the PSCCH. The remaining bits of the transmitter ID (source ID) and the destination ID can be transmitted using a MAC header transmitted through the PSSCH or MAC PDU.

[0177] (4-1) The remaining bits of the transmitter ID may be transmitted using a MAC header transmitted via PSSCH or MAC PDU. For example, the MSB or LSB [s1] bit of the [s] bit of the transmitter ID (source ID) may be transmitted via PSCCH, and the remaining [s2] bits may be transmitted using a medium access control (MAC) header transmitted via PSSCH or MAC protocol data unit (PDU) ([s1]+[s2]=[s]).

[0178] (4-2) The remaining bits of the destination ID may be transmitted via the PSSCH or the MAC header transmitted by the MAC PDU. For example, the MSB or LSB [d1] bit of the [d] bit of the destination ID may be transmitted via the PSCCH, and the remaining [d2] bits may be transmitted using the MAC header transmitted via the PSSCH or the MAC PDU ([d1]+[d2]=[d]).

[0179] (4-3) The V2X receiving UE that obtains information about the transmitter ID (source ID) and the destination ID transmitted through the SCI of the PSCCH can determine whether the [d1] bit of the destination ID included in the SCI corresponds to the V2X receiving UE itself. When the destination ID corresponds to the V2X receiving UE itself, the V2X receiving UE can decode the PSSCH through the resource allocation information of the PSSCH included in the SCI. When the V2X receiving UE successfully decodes the PSSCH, the V2X receiving UE can generate a [d] bit destination ID using the remaining bits (that is, [d2] bits) of the destination ID transmitted through the PSSCH and the [d1] bit of the destination ID received through the SCI. The V2X receiving UE can compare the generated destination ID with the destination ID received from the upper layer of the V2X receiving UE, and finally identify whether the corresponding PSSCH is the sidelink data to be received by the V2X receiving UE. When it is identified through the final identification that the corresponding PSSCH is the sidelink data to be received by the V2X receiving UE, the V2X receiving UE can transmit the decoding result to the upper layer. When it is identified through final recognition that the corresponding PSSCH is not the sidelink data to be received by the V2X receiving UE, the V2X receiving UE may delete the decoding result from its own buffer without transmitting it to a higher layer.

[0180] (4-4) At the same time, the V2X receiving UE that successfully decodes the PSSCH and recognizes that the corresponding PSSCH is the sidelink data that the V2X receiving UE will receive can send ACK information to the V2X sending UE through the PSFCH. When the V2X receiving UE fails to decode the PSSCH, the V2X receiving UE can send NACK information to the V2X sending UE through the PSFCH. At this time, the V2X receiving UE can initialize the scrambling sequence generator and perform scrambling as shown in Formula 4 based on at least one of the transmitter ID (source ID), destination ID, and cell ID obtained by method 2) and the above method.

[0181] (4-5) When the destination ID transmitted through the SCI in the above example does not correspond to the V2X receiving UE, the V2X receiving UE may delete the corresponding SCI from its own buffer and may not decode the PSSCH.

[0182] In operation S705, quadrature phase shift keying (QPSK) modulation may be performed on the scrambled sequence.

[0183] In operation S706, the QPSK modulated symbol may be mapped to a frequency resource (resource element (RE)) as a physical resource of the PSFCH. At this time, a demodulation reference signal (DMRS) may be added to the PSFCH, and the QPSK modulated symbol may be mapped to the remaining frequency resources except the frequency resource of the PSFCH in which the DMRS is transmitted.

[0184] Although not in Figure 7 As shown in FIG. 1 , after operation S706, an OFDM symbol may be generated through an inverse fast Fourier transform (IFFT), a cyclic prefix (CP) may be added to the OFDM symbol, and the OFDM symbol may be transmitted through the antenna.

[0185] Although the above example has been described based on unicast communication in which the number of NR V2X receiving UEs is 1, the present disclosure can also be applied to multicast communication in which the number of NR V2X receiving UEs is 2 or more.

[0186] Figure 8 The process of V2X UE sending a sidelink feedback channel in a wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Figure 8 An example of a signal processing method by which a V2X UE transmits a sidelink feedback channel according to an embodiment is shown.

[0187] Reference Figure 8 In operation S801, the NR V2X receiving UE may Figure 7 At least one of the methods described in operation S701 of the method of obtaining a parameter for sending a sidelink feedback channel. Information about the parameter for sending a sidelink feedback channel may include Figure 6 PSFCH related information described in Figure 7 The PSFCH-related information described in operation S701 and at least one of the following information.

[0188] 1. Information about code resources of PSFCH: Code resources may include resources distinguished by codes such as scrambling codes or orthogonal cover codes that can be used for PSFCH and resources distinguished by different sequences (and cyclic shifts (CS) applied to the sequences). For example, when HARQ ACK / NACK is sent over PSFCH, there may be a CS that can be used for ACK and a CS that can be used for NACK.

[0189] 2. Information about PSFCH format: For example, when it is assumed that two PSFCH formats are supported, PSFCH format 1 can be used to send 2 bits or less of SFCI information, and PSFCH format 2 can be used to send 3 bits or more of SFCI information. Therefore, in the above example, the information about the PSFCH format can be PSFCH format 1 or PSFCH format 2.

[0190] In operation S802, the NR V2X receiving UE may generate SFCI information to be sent through the PSFCH according to the configuration or instruction of the BS or the NR V2X sending UE.

[0191] 1. For example, it may be configured or indicated whether only NACK information should be sent or ACK information and NACK information should be sent separately.

[0192] In operation S803, a sequence may be generated using the SFCI information generated in operation S802 and one of the methods described in operation S801.

[0193] 1. A sequence can be mapped to one piece of SFCI information. For example, 1-bit ACK information can indicate sequence 1, and 1-bit NACK information can indicate sequence 2. 2-bit ACK information can indicate sequence 3, and 2-bit NACK information can indicate sequence 4. In the above examples, different sequences can refer to using different CS values. More specifically, when 1-bit ACK / NACK information is sent in the above example, the ACK information can use CS=0 and the NACK information can use CS=6. Similarly, when 2-bit ACK / NACK information is sent, (ACK, ACK) information can use CS=0, (ACK, NACK) information can use CS=3, (NACK, ACK) information can use CS=6, and (NACK, NACK) information can use CS=9.

[0194] 2. In the above example, the length of the sequence may be proportional to the size of the frequency resource configured or indicated by the BS or V2X transmitting UE for PSFCH transmission. For example, when the size of the frequency resource of the PSFCH is configured or indicated as 1, the length of the sequence that the V2X receiving UE should generate may be 12×1=12. When the size of the frequency resource of the PSFCH is configured or indicated as 2, the length of the sequence that the V2X receiving UE should generate may be 12×2=24.

[0195] 3. In another example of configuration of sequence length, the BS or V2X transmitting UE may configure or indicate a set of sizes of frequency resources that the V2X receiving UE may use, and the V2X receiving UE may select and use one size of frequency resources from the corresponding set. At this time, the selection reference may follow the reception quality of the PSCCH and / or PSSCH received by the V2X receiving UE from the V2X transmitting UE. For example, when the reception quality is good, a sequence with a short length may be selected, that is, frequency resources of small size may be used. When the reception quality is not good, a sequence with a long length may be selected. The BS or V2X transmitting UE may configure or indicate a threshold value that provides a determination reference by which the V2X receiving UE determines whether the reception quality is good or not. More specifically, when the quality of the channel received by the V2X receiving UE is equal to or less than a threshold value configured or indicated by the BS or V2X transmitting UE through comparison therebetween, it may be determined that the channel quality is not good. In the opposite case, the channel quality may be good.

[0196] In operation S804, the generated sequence may be mapped to frequency resources (resource elements (REs)) as physical resources of the PSFCH. Figure 7 Different from operation S706, DMRS may not be added.

[0197] Although not in Figure 8 As shown in FIG. 8 , after operation S804, an OFDM symbol may be generated through an inverse fast Fourier transform (IFFT), a cyclic prefix (CP) may be added to the OFDM symbol, and the OFDM symbol may be transmitted through an antenna.

[0198] Although the above example has been described based on unicast communication in which the number of NR V2X receiving UEs is 1, the present disclosure can also be applied to multicast communication in which the number of NR V2X receiving UEs is 2 or more.

[0199] Fig. 9 The process of V2X UE sending a sidelink feedback channel in a wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Fig. 9 Another example of a signal processing method by which a V2X UE transmits a sidelink feedback channel according to an embodiment is shown.

[0200] Reference Fig. 9 In operation S901, the NR V2X receiving UE may Figure 7 At least one of the methods described in operation S701 of the method of obtaining a parameter for sending a sidelink feedback channel. Information about the parameter for sending a sidelink feedback channel may include Figure 6 PSFCH related information described in Figure 7The PSFCH related information described in operation S701, Figure 8 At least one of the PSFCH related information described in operation S801.

[0201] In operation S902, the NR V2X receiving UE may generate SFCI information transmitted through the PSFCH according to the configuration or instruction of the BS or the NR V2X transmitting UE. Figure 7 As described in operation S702 of the embodiment, it can be configured or indicated whether only NACK information should be sent or ACK information and NACK information should be sent separately.

[0202] In operation S903, binary phase shift keying (BPSK) or QPSK modulation may be performed using the SFCI information generated in operation S902.

[0203] 1. For example, the V2X receiving UE may perform operation S902 or Figure 7 Whether to send 1-bit SFCI information or 2-bit SFCI information is determined by one of the methods in operation S702.

[0204] 2. When the V2X receiving UE determines to send 1-bit SFCI information, the corresponding SFCI information can be BPSK modulated. When the V2X receiving UE determines to send 2-bit SFCI information, the corresponding SFCI information can be QPSK modulated.

[0205] 3. The SFCI information after BPSK or QPSK modulation can be 1 modulated symbol. For example, the SFCI information after BPSK modulation can be a BPSK modulated symbol, and the SFCI information after QPSK modulation can be a QPSK modulated symbol. For example, when the SFCI information is BPSK modulated, "+1" can indicate ACK information and "-1" can indicate NACK information. Depending on the situation, vice versa. When the SFCI information is QPSK modulated, "+1" can indicate (ACK, ACK) information, "-j" can indicate (ACK, NACK) information, "-1" can indicate (NACK, ACK) information, and "+j" can indicate (NACK, NACK) information. However, this is only an embodiment of the present disclosure, and another one-to-one correspondence between (ACK, ACK), (ACK, NACK), (NACK, ACK), (NACK, NACK) and {+1, -1, +j, -j} can be used.

[0206] In operation S904, the SFCI information modulated by BPSK or QPSK in operation S903 may be sequence modulated using at least one of the following methods.

[0207] 1. At this time, sequence modulation may mean that the symbol after BPSK or QPSK modulation of operation S903 (that is, "+1" or "-1" in the case of BPSK modulation, or "+1", "-j", "-1" or "+j" in the case of QPSK modulation) is multiplied by a sequence of length M.

[0208] (1) The sequence length M may be proportional to the size of the frequency resource configured or indicated by the BS or V2X transmitting UE for PSFCH transmission. For example, when the size of the frequency resource of the PSFCH is configured or indicated as 1, the length M of the sequence that the V2X receiving UE should generate may be 12×1=12. When the size of the frequency resource of the PSFCH is configured or indicated as 2, the length M of the sequence that the V2X receiving UE should generate may be 12×2=24.

[0209] (2) In another example of configuration of sequence length, the BS or V2X transmitting UE may configure or indicate a set of sizes of frequency resources that the V2X receiving UE may use, and the V2X receiving UE may select and use one size of frequency resources from the corresponding set. At this time, the selection reference may follow the reception quality of the PSCCH and / or PSSCH received by the V2X receiving UE from the V2X transmitting UE. For example, when the reception quality is good, a sequence with a short length (e.g., a frequency resource of small size) may be selected. When the reception quality is poor, a sequence with a long length may be selected. The BS or V2X transmitting UE may configure or indicate a threshold value that provides a determination reference relative to good or poor reception quality. More specifically, when the quality of the channel received by the V2X receiving UE is equal to or less than a threshold value configured or indicated by the BS or V2X transmitting UE through comparison therebetween, it may be determined that the channel quality is poor. In the opposite case, the channel quality may be good.

[0210] 2. In addition to the meaning of multiplying the sequence length M by the above-mentioned BPSK or QPSK modulation system, sequence modulation can also have the following meanings.

[0211] (1) An orthogonal cover code (OCC) may be additionally multiplied with the generated sequence. This is to share the PSFCH using the same time / frequency resources between different users. For example, the same time / frequency resources are used for user multiplexing, but different code resources, that is, different OCCs, may be used. At this time, the axis through which the OCC is multiplied may be the frequency axis before performing an inverse fast Fourier transform (IFFT) or the time axis after performing an IFFT.

[0212] In operation S905, the generated sequence may be mapped to frequency resources (resource elements (REs)) as physical resources of the PSFCH. Figure 7Different from operation S706, DMRS may not be added.

[0213] Although not in Fig. 9 As shown in FIG. 1 , after operation S905 , an OFDM symbol may be generated through an inverse fast Fourier transform (IFFT), a cyclic prefix (CP) may be added to the OFDM symbol, and the OFDM symbol may be transmitted through an antenna.

[0214] Although the above example has been described based on unicast communication in which the number of NR V2X receiving UEs is 1, the present disclosure can be applied to multicast communication in which the number of NR V2X receiving UEs is 2 or more.

[0215] Fig.10 Sidelink resources through which a V2X UE performs V2X communication in a wireless communication system according to an embodiment of the present disclosure are illustrated. Fig.10 An example of sidelink resources through which a V2X UE performs V2X communication according to an embodiment is shown.

[0216] Reference Fig.10 , the sidelink resource 1003 may include K symbols 1001 on the time axis and M resource blocks (RBs) 1002 on the frequency axis. One resource block 1002 may consist of 12 subcarriers. The K symbols 1001 may be physically or logically continuous on the time axis. When the K symbols are logically continuous, the K symbols are physically discontinuous. Similarly, the M resource blocks 1002 may be physically or logically continuous on the frequency axis. When the K symbols are logically continuous, the K symbols are physically discontinuous.

[0217] Although not in Fig.10 As shown, the V2X transmitting UE can use Fig.10 Some or all of the sidelink resources 1003 may be used to send sidelink control information or data information. The V2X receiving UE may use Fig.10 some or all of the sidelink resources 1003 to receive sidelink control information or data information.

[0218] In another example, a V2X receiving UE may use Fig.10 Some or all of the sidelink resources 1003 are used to send sidelink feedback information to the V2X UE. Fig.10 In the embodiment, K and M may be the same or may vary according to the time point when the sidelink control information or the sidelink data information is sent. For example, K and M at the time point T1 when the V2X transmitting UE sends the sidelink control information or the sidelink data information may be the same as or different from K and M at the time point T2 when the sidelink control information or the sidelink data information is sent.

[0219] Similarly, refer to Fig.10 , K and M may be the same or may vary according to the time point at which the V2X receiving UE receives the sidelink control information or the sidelink data information. For example, K and M at the time point T1 at which the V2X receiving UE receives the sidelink control information or the sidelink data information may be the same as or different from K and M at the time point T2 at which the sidelink control information or the sidelink data information is received.

[0220] Reference Fig.10 , K and M may be the same or may vary according to the time point at which the V2X receiving UE sends the sidelink feedback information to the V2X sending UE. For example, K and M at the time point T1 at which the V2X receiving UE sends the sidelink feedback information to the V2X sending UE may be the same as or different from K and M at the time point T2 at which the sidelink feedback information is sent to the V2X sending UE.

[0221] Fig.11 The multiplexing scheme of the sidelink control channel, the sidelink data channel and the sidelink feedback channel in the sidelink resource in the wireless communication system according to the embodiment of the present disclosure is shown. Specifically, Fig.11 An example of a multiplexing scheme of a sidelink control channel, a sidelink data channel and a sidelink feedback channel within a sidelink resource according to an embodiment is shown.

[0222] Reference Fig.11 , the sidelink control channel (physical sidelink control channel (PSCCH)) 1105 and the sidelink data channel (physical sidelink shared channel (PSSCH)) 1106 can be multiplexed on the time axis and the frequency axis. For example, time division multiplexing (TDM) and frequency division multiplexing (FDM) are shown.

[0223] The PSCCH 1105 and the PSSCH 1106 may include different numbers of resource blocks on the frequency axis. For example, on the frequency axis, the PSCCH 1105 may include N1 frequency blocks 1003 and the PSSCH 1106 may include M frequency blocks 1104. N1 may be less than M (N1 < M). However, the case where the PSCCH 1105 and the PSSCH 1106 have the same number of resource blocks (M RBs) on the frequency axis is not excluded. The PSCCH 1105 and the PSSCH 1106 may be frequency-division multiplexed in K1 symbols 1110 on the time axis, and only the PSSCH may be transmitted without transmitting the PSCCH in the remaining K2 symbols 1111. For example, the PSCCH 1105 may include N1 frequency blocks 1103 on the frequency axis and K1 symbols 1110 on the time axis. The PSSCH 1106 may include N2 blocks 1104 during the length of the K1 symbols 1110, and the PSSCH 1106 and the PSCCH 1105 may be frequency-division multiplexed. The PSSCH may include M frequency blocks 1102 during the length of the K2 symbols 1111 without frequency-division multiplexing with the PSCCH 1105. The sum of N2 and N1 may be the same as or different from M.

[0224] Although Fig.11 it is shown that the N1 frequency blocks 1103 included in the PSSCH 1106 including (M - N2) frequency blocks and the PSCCH 1105 are physically continuously located, they are physically discontinuous. For example, they may be logically continuous but physically discontinuous. Meanwhile, K1 and K2 may be the same as or different from each other. When K1 and K2 are different from each other, K1 > K2 or K1 < K2. The V2X transmitting UE may insert the time / frequency allocation information of the PSSCH 1106 into the sidelink control information transmitted through the PSCCH 1105 and transmit the sidelink control information. The V2X receiving UE may receive and decode the PSCCH1105, obtain the time / frequency allocation information of the PSSCH 1106, and then decode the PSSCH 1106. Although Fig.11 it is shown that the PSSCH 1106 including K2 symbols is physically continuous with the K1 symbols 1110 included in the PSCCH 1105, the PSSCH1106 may be physically discontinuous. For example, they may be logically continuous but physically discontinuous.

[0225] Fig.11A case where a sidelink feedback channel (physical sidelink feedback channel (PSFCH)) exists within a sidelink resource including K symbols 1101 is shown. In this case, the sidelink resource may include K1 symbols 1110 of PSCCH 1105, K2 symbols 1111 of PSSCH 1106 when only symbols that are not frequency-division multiplexed with PSCCH 1105 are considered, and (K1 1110+K2 1111) symbols of PSSCH 1106 when symbols that are FDMed with PSCCH 1105 are considered, guard symbol #1 1112, PSFCH 1108, K symbols 1113, and guard symbol #2 1114. For example, K11110+K2 1111+guard symbol #1 1112+K2 1113+guard symbol #2 1114=K 1101. At this time, the guard symbol #1 1112 and the guard symbol #2 1114 may be one or more OFDM symbols. When the V2X transmitting UE transmits PSCCH 1105 and PSSCH 1106 and receives PSFCH 1108, the guard symbol #1 1112 is required to switch between transmission and reception. On the other hand, when the V2X receiving UE receives PSCCH 1105 and PSSCH 1106 and transmits PSFCH 1108, the gap 1107 of the guard symbol #1 1112 is required to switch between reception and transmission. Similarly, when the V2X transmitting UE receives PSFCH 1108 from the V2X receiving UE and transmits PSCCH 1105 and PSSCH 1106 in the next sidelink resource, the gap 1109 of the guard symbol #2 1114 is required to switch between reception and transmission. When the V2X receiving UE sends PSFCH 1108 to the V2X transmitting UE and receives PSCCH 1105 and PSSCH 1106 in the next sidelink resource, a gap 1109 of the guard symbol #2 1114 is required to switch between transmission and reception.

[0226] At the same time, although not Fig.11 , but one of the guard symbol #1 1112 and the guard symbol #2 1114 may be 0. For example, when the V2X transmitting UE receives PSFCH 1108 and receives PSCCH 1105 and PSSCH 1106 from another UE in the next sidelink resource, there is no need for conversion between reception and transmission, so the number of guard symbols #2 1114 may be 0. The present disclosure does not exclude the case where at least one of K1 1110, K2 1111, and K3 1113 is 0.

[0227] although Fig.11It is shown that the size of the frequency resource block of PSFCH 1108 is the same as that of PSSCH 1106 (that is, M RBs), but the size of the resource block of PSFCH 1108 on the frequency axis may be the same as or different from the size of the resource blocks of PSCCH 1105 and PSSCH 1106. The V2X receiving UE may decode PSSCH 1106, insert the result (that is, ACK / NACK information) into PSFCH 1108, and transmit the ACK / NACK information to the V2X transmitting UE.

[0228] Fig.12 The structure of the sidelink feedback channel in the wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Fig.12 A structural example of a sidelink feedback channel according to an embodiment is shown.

[0229] Reference Fig.12 , the sidelink feedback channel (PSFCH) can be used to send Figure 7 The process of generating SFCI information. Fig.12 It is shown that the DMRS overhead is 1 / 3 (that is, 4 REs are used as DMRS 1202 among 12 resource elements (REs) 1201), but the present disclosure is not limited thereto. For example, when the DMRS overhead is 1 / 4 (that is, 3 REs are used as DMRS 1202 among 12 resource elements (REs) 1201), DMRS 1202 may be mapped to RE index numbers 1, 5, and 9 (or 2, 6, and 10), and SFCI may be mapped to the remaining RE indexes.

[0230] although Fig.12 The structure of the PSFCH in one RB including 12 REs 1201 is shown, but the structure can be equally applied to a PSFCH including two or more RBs. For example, when it is assumed that two RBs correspond to the size of the PSFCH frequency resource transmitted by one V2X receiving UE, the DMRS can be mapped to RE indexes 1, 4, 7, 10, 13, 16, 19, and 22, and the SFCI can be mapped to the remaining RE indexes.

[0231] When the PSFCH transmitted by a V2X receiving UE includes two or more OFDM symbols on the time axis, the PSFCH 1203 including one OFDM symbol may be repeated. For example, when the PSFCH includes two OFDM symbols (as indicated by reference numeral 1204), or when the PSFCH includes three OFDM symbols (as indicated by reference numeral 1205), the PSFCH 1203 including one OFDM symbol may be repeated, as shown in FIG. Fig.12 Although not shown in Fig.12 As shown in FIG. 1 , based on this principle, an extension of the structure of the PSFCH including four or more OFDM symbols is possible.

[0232] Fig.12 The PSFCH shown in Fig.11 K3 symbols within the sidelink resource. At the same time, when Figures 8 to 9 When the SFCI information generated by the method is sent through the PSFCH, the SFCI information can be mapped to all REs of the PSFCH without any RE being used Fig.12 However, in this case, there is no DMRS, so the channel estimation performance of the V2X transmitting UE receiving the PSFCH will be degraded. Fig.12 As shown in Figures 8 to 9 The SFCI information generated by the method can only be mapped to Fig.12 The remaining REs other than the REs used for DMRS transmission are shown in FIG.

[0233] although Fig.12 It is shown that even if the number of OFDM symbols increases, DMRS 1202 exists in the same RE 1201 on the frequency axis, but the present disclosure is not limited thereto. For example, when PSFCH 1204 includes two OFDM symbols, the position of the DMRS RE in the second OFDM symbol may be different from the position of the DMRS RE existing in the first OFDM symbol. Similarly, when PSFCH 1205 includes three OFDM symbols, the positions of the DMRS RE in each OFDM symbol may be different from each other. In another example, when PSFCH 1205 includes three or more OFDM symbols, the positions of the DMRS RE in two or more OFDM symbols may be the same as each other.

[0234] Fig.13 The structure of the sidelink feedback channel in the wireless communication system according to an embodiment of the present disclosure is shown. Specifically, Fig.13 Another example of the structure of a sidelink feedback channel according to an embodiment is shown.

[0235] Reference Fig.13 , the sidelink feedback channel (PSFCH) can be used to send Figure 7 The process of generating SFCI information. Fig.13It is shown that the DMRS overhead is 1 / 3 (that is, 4 REs are used as DMRS 1302 among 12 resource elements (REs) 1301), but the present disclosure is not limited thereto. For example, when the DMRS overhead is 1 / 4 (that is, 3 REs are used as DMRS 1302 among 12 resource elements (REs) 1301), DMRS 1202 may be mapped to RE index numbers 1, 5, and 9 (or 2, 6, and 10), and SFCI may be mapped to the remaining RE indexes.

[0236] although Fig.13 The structure of the PSFCH 1303 in one RB including 12 REs is shown, but the structure may be equally applied to the PSFCH 1304 including two or more RBs. For example, when it is assumed that two RBs correspond to the size of the PSFCH frequency resource transmitted by one V2X receiving UE, the DMRS may be mapped to RE indexes 1, 4, 7, 10, 13, 16, 19, and 22, and the SFCI may be mapped to the remaining RE indexes. Fig.13 As shown in FIG. 1 , based on this principle, an extension of the structure of the PSFCH including four or more OFDM symbols is possible.

[0237] When the PSFCH transmitted by a V2X receiving UE includes two or more OFDM symbols on the time axis, Fig.12 The PSFCH including 1 OFDM symbol is repeated in Fig.13 In , DMRS may only exist in odd-numbered OFDM symbols, but may not exist in even-numbered OFDM symbols. Fig.13 In , DMRS may only exist in the first OFDM symbol and the third OFDM symbol, but may not exist in the second OFDM symbol. Fig.13 In the embodiment, the PSFCH may alternately include OFDM symbols in which the DMRS exists and OFDM symbols in which the DMRS does not exist.

[0238] Fig.13 The PSFCH shown in Fig.11 K3 symbols within the sidelink resource. At the same time, when Figures 8 to 9 When the SFCI information generated by the method is sent via PSFCH, the SFCI information can be transmitted without Fig.13 In the case of 1302 in FIG, all REs are mapped to PSFCH. However, in this case, there is no DMRS, so the channel estimation performance of the V2X transmitting UE receiving PSFCH will be degraded. Fig.13 As shown in Figures 8 to 9The SFCI information generated by the method can only be mapped to Fig.13 The remaining REs other than the REs for transmitting the DMRS 1302 shown in FIG.

[0239] although Fig.13 It is shown that even if the number of OFDM symbols increases, DMRS exists in the same RE on the frequency axis, but the present disclosure is not limited to this. For example, when PSFCH 1305 includes three OFDM symbols, the position of DMRS RE in the third OFDM symbol may be different from the position of DMRS RE existing in the first OFDM symbol. Similarly, when PSFCH includes four or more OFDM symbols, the positions of DMRS RE in each OFDM symbol may be different from each other. In another example, when PSFCH 1205 includes four or more OFDM symbols, the positions of DMRS RE in OFDM symbols in which two or more DMRS exist may be the same as each other.

[0240] The methods disclosed in the claims and / or methods according to various embodiments described in the specification of the present disclosure may be implemented by hardware, software, or a combination of hardware and software.

[0241] When the method is implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors in an electronic device. The at least one program may include instructions that cause the electronic device to execute the method according to various embodiments of the present disclosure as defined in the appended claims and / or disclosed herein.

[0242] The program (software module or software) may be stored in a non-volatile memory, including random access memory and flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage, compact disk-ROM (CD-ROM), digital versatile disk (DVD) or other types of optical storage devices or tape cassettes. Alternatively, any combination of some or all of them may form a memory in which the program is stored. In addition, a plurality of such memories may be included in an electronic device.

[0243] In addition, the program can be stored in an attachable storage device that can access the electronic device through a network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), and a storage area network (SAN), or a combination thereof. Such a storage device can access the electronic device via an external port. In addition, a separate storage device on a communication network can access the portable electronic device.

[0244] In the above detailed embodiments of the present disclosure, the elements disclosed in the present disclosure are expressed in the singular or plural, depending on the specific embodiment proposed. However, for ease of description, the singular form or plural form is appropriately selected for the presented situation, and the present disclosure is not limited by the elements expressed in the singular or plural. Therefore, an element expressed in the plural may also include a single element, or an element expressed in the singular may also include multiple elements.

[0245] While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a first user equipment UE in a wireless communication system, the method comprising: Receiving sidelink configuration information from a base station BS via radio resource control RRC signaling; Sending sidelink control information SCI for sidelink data to the second UE based on the configuration information; sending the sidelink data to the second UE on a physical sidelink shared channel PSSCH based on the SCI; and receiving hybrid automatic repeat request HARQ-acknowledgement ACK information about a physical sidelink feedback channel PSFCH from the second UE, wherein the SCI includes information about frequency resource allocation for the sidelink data, information about time resource allocation for the sidelink data, information about a modulation and coding scheme MCS for the sidelink data, and information associated with a demodulation reference signal for the sidelink data, and The configuration information includes a period of the PSFCH resources and a time gap between the PSFCH and the PSSCH.

2. The method according to claim 1, wherein: The SCI includes a first SCI transmitted on a physical sidelink control channel PSCCH and a second SCI transmitted on the PSSCH, and The SCI also includes information about the HARQ process identifier ID, information about the redundancy version, information about the source ID and information about the destination ID.

3. The method according to claim 1, in, The configuration information includes at least one of the following: The number of time slots of the period of the PSFCH; A set of frequency resources in a resource pool used for the PSFCH.

4. A method performed by a second user equipment UE in a wireless communication system, the method comprising: Receiving sidelink configuration information from a base station BS via radio resource control RRC signaling; receiving sidelink control information SCI for sidelink data from the first UE based on the configuration information; receiving the sidelink data from the first UE on a physical sidelink shared channel (PSSCH) based on the SCI; and sending hybrid automatic repeat request HARQ-acknowledgement ACK information about a physical sidelink feedback channel PSFCH to the first UE, wherein the SCI includes information about frequency resource allocation for the sidelink data, information about time resource allocation for the sidelink data, information about a modulation and coding scheme MCS for the sidelink data, and information associated with a demodulation reference signal for the sidelink data, and The configuration information includes a period of the PSFCH resources and a time gap between the PSFCH and the PSSCH.

5. The method according to claim 4, wherein: The SCI includes a first SCI transmitted on a physical sidelink control channel PSCCH and a second SCI transmitted on the PSSCH, and The SCI also includes information about the HARQ process identifier ID, information about the redundancy version, information about the source ID and information about the destination ID.

6. The method according to claim 4, in, The SCI instructs the UE to send the HARQ-ACK information, where the HARQ-ACK information includes ACK or non-ACK (NACK), or only NACK.

7. The method according to claim 6, in, A first sequence cyclic shift corresponding to the HARQ-ACK information including NACK is different from a second sequence cyclic shift corresponding to the HARQ-ACK including ACK.

8. The method according to claim 7, further comprising: A sequence is generated based on the first sequence cyclic shift or the second sequence cyclic shift.

9. The method according to claim 8, wherein: The sequence is mapped to the resources of the PSFCH.

10. The method according to claim 9, in, The PSFCH resource includes a first physical resource and a second physical resource, and Wherein, when a first symbol immediately precedes a second symbol, the first physical resource corresponding to the first symbol is repeated to the second physical resource corresponding to the second symbol.

11. The method according to claim 4, in, The configuration information also includes a set of frequency resources in a resource pool used for the PSFCH transmission.

12. The method according to claim 11, wherein: The set of frequency resources is indicated by a bitmap.

13. A second user equipment UE used in a wireless communication system, comprising: Transceiver; at least one processor coupled to the transceiver and configured to: Receiving sidelink configuration information from a base station BS via radio resource control RRC signaling; receiving sidelink control information SCI for sidelink data from the first UE based on the configuration information; receiving the sidelink data from the first UE on a physical sidelink shared channel (PSSCH) based on the SCI; and sending hybrid automatic repeat request HARQ-acknowledgement ACK information about a physical sidelink feedback channel PSFCH to the first UE, wherein the SCI includes information about frequency resource allocation for the sidelink data, information about time resource allocation for the sidelink data, information about a modulation and coding scheme MCS for the sidelink data, and information associated with a demodulation reference signal for the sidelink data, and The configuration information includes a period of the PSFCH resources and a time gap between the PSFCH and the PSSCH.

14. The second UE according to claim 13, wherein: The SCI includes a first SCI transmitted on a physical sidelink control channel PSCCH and a second SCI transmitted on the PSSCH, and The SCI also includes information about the HARQ process identifier ID, information about the redundancy version, information about the source ID and information about the destination ID.

15. The second UE according to claim 13, in, The SCI instructs the UE to send the HARQ-ACK information, where the HARQ-ACK information includes ACK or non-ACK (NACK), or only NACK.

16. The second UE according to claim 15, in, A first sequence cyclic shift corresponding to the HARQ-ACK information including NACK is different from a second sequence cyclic shift corresponding to the HARQ-ACK including ACK.

17. The second UE according to claim 16, wherein: The at least one processor is further configured to: A sequence is generated based on the first sequence cyclic shift or the second sequence cyclic shift.

18. The second UE according to claim 17, wherein: The sequence is mapped to the resources of the PSFCH.

19. The second UE according to claim 18, in, The PSFCH resource includes a first physical resource and a second physical resource, and Wherein, when a first symbol immediately precedes a second symbol, the first physical resource corresponding to the first symbol is repeated to the second physical resource corresponding to the second symbol.

20. The second UE according to claim 13, in, The configuration information also includes a set of frequency resources in a resource pool used for the PSFCH transmission.

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