Method and apparatus for sidelink multicast communication

Abstract

Methods and apparatus for sidelink multicast communications are disclosed. A method for a first user equipment (UE), the method comprising: receiving information for a plurality of synchronization signal / physical broadcast channel (SS / PBCH) block transmissions for sidelink communication from a base station; transmitting one or more SS / PBCH blocks in a sidelink based on the information; and transmitting a reference signal for sidelink measurement in the sidelink; wherein the number of the one or more SS / PBCH blocks is equal to or less than the number of SS / PBCH block transmissions. Therefore, communication system performance can be improved.

Description

[0001] This application is a divisional application of the invention patent application filed on January 29, 2020, entering the Chinese national phase on July 30, 2021, with application number 202080011824.2, entitled "Method and apparatus for sidelink multicast communication". Technical Field

[0002] This invention relates generally to sidelink communication technology, and more specifically, to beamforming-based sidelink communication technology for supporting multicast services. Background Technology

[0003] Fifth-generation (5G) communication systems (e.g., New Radio (NR) systems) using frequency bands higher than those of fourth-generation (4G) communication systems (e.g., Long Term Evolution (LTE) or LTE-A Advanced (LTE-A) systems), as well as frequency bands used by 4G communication systems, have been considered for processing wireless data. 5G communication systems can support enhanced mobile broadband (eMBB) communication, ultra-reliable and low-latency communication (URLLC), massive machine-type communication (mMTC), and more.

[0004] 4G and 5G communication systems can support vehicle-to-everything (V2X) communication. V2X communication supported in cellular communication systems, such as 4G and 5G systems, can be referred to as "cellular-V2X (C-V2X) communication." V2X communication (e.g., C-V2X communication) can include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, and vehicle-to-network (V2N) communication, among others.

[0005] In cellular communication systems, V2X communication (e.g., C-V2X communication) can be performed based on "sidelink" communication technologies (e.g., Proximity Service (ProSe) communication technologies, Device-to-Device (D2D) communication technologies, etc.). For example, a sidelink channel can be established between vehicles participating in V2V communication, and the sidelink channel can be used to perform communication between vehicles.

[0006] Simultaneously, high-frequency bands (e.g., millimeter-wave bands) can be used to perform sidelink communication. In this case, sidelink communication can be performed in a beam scanning scheme. Therefore, the transmitting terminal can transmit sidelink signals and / or channels in all directions by rotating the beam. Sidelink communication can support broadcast, multicast, and unicast services.

[0007] When sidelink communication supports multicast services, the location of the receiving terminals participating in the multicast service may be restricted to a specific area. Even in this case, if the transmitting terminal transmits sidelink signals and / or channels in all directions according to a beam scanning scheme, transmission delays may occur due to unnecessary transmission processes (e.g., beams being sent to areas where the receiving terminal does not exist), and power loss may also increase. Furthermore, unnecessary transmission processes may interfere with other communication nodes. Summary of the Invention

[0008] Therefore, exemplary embodiments of the present invention provide a method and apparatus for beamforming-based sidelink communication to support multicast services.

[0009] According to an exemplary embodiment of the present invention, an operation method of a transmitting terminal in a communication system may include transmitting a synchronization signal / physical broadcast channel (SS / PBCH) block for sidelink communication in all directions using a beam scanning scheme; receiving first feedback information of the SS / PBCH block from a plurality of receiving terminals; and transmitting the sidelink channel in a specific direction using a beam of the transmitting terminal determined based on the first feedback information, wherein the transmission area corresponding to the specific direction is narrower than the transmission area corresponding to the all directions.

[0010] The SS / PBCH block can be transmitted within a beam scanning interval configured by the transmitting terminal and the base station to which it is connected, and the beam scanning interval can be configured within the bandwidth portion (BWP) used for sidelink communication.

[0011] The first feedback information may include the beam index of the transmitting terminal selected based on beam quality measured according to the SS / PBCH block. The transmission interval can be configured based on the first feedback information, and the sidelink channel can be transmitted to multiple receiving terminals within the transmission interval using a beam scanning scheme.

[0012] The operation method may further include classifying multiple receiving terminals into one or more groups based on the locations of multiple receiving terminals identified by a first feedback information, wherein, for each of the one or more groups, the sidelink channel transmits in a beam scanning scheme during the transmission interval.

[0013] The operation method may further include sending configuration information of the transmission interval to multiple receiving terminals before transmitting the sidelink channel, wherein the configuration information of the transmission interval includes information indicating the start point of the transmission interval, information indicating the length of the transmission interval, information indicating the bandwidth of the transmission interval, information indicating the period of the transmission interval, and identifiers of one or more receiving terminals among the multiple receiving terminals that perform sidelink communication within the transmission interval.

[0014] The operation method may further include receiving second feedback information about the sidelink channel from multiple receiving terminals; and determining whether to perform a beam update operation based on the second feedback information, wherein the second feedback information includes one or more of a Hybrid Automatic Repeat Request (HARQ) response and quality information of the sidelink channel.

[0015] The sidelink channel may include the Physical Sidelink Control Channel (PSCCH) and the Physical Sidelink Shared Channel (PSSCH), and the PSCCH may include the scheduling information of the PSSCH and the triggering information of the beam update operation.

[0016] Furthermore, according to an exemplary embodiment of the present invention, the operation method of the receiving terminal in the communication system may include receiving a synchronization signal / physical broadcast channel (SS / PBCH) block for sidelink communication from a transmitting terminal at a beam scanning interval; selecting a beam index of the transmitting terminal based on quality information measured according to the SS / PBCH block; sending first feedback information including the beam index to the transmitting terminal; and receiving a sidelink channel from the transmitting terminal in a transmission interval configured based on the first feedback information, wherein the SS / PBCH block is transmitted in all directions of the transmitting terminal within the beam scanning interval, and the sidelink channel is transmitted in a specific direction of the transmitting terminal within the transmission interval, and the transmission area corresponding to the specific direction is narrower than the transmission area corresponding to the all directions.

[0017] The SS / PBCH block can be received within a beam scanning interval configured by the receiving terminal and the base station to which it is connected, and the beam scanning interval can be configured within the bandwidth portion (BWP) for sidelink communication. Transmission intervals can be configured for multiple receiving terminals, including the receiving terminal, and sidelink channels for each of the multiple receiving terminals can be transmitted within the transmission interval using a beam scanning scheme.

[0018] The operation method may further include receiving configuration information of the transmission interval from the transmitting terminal before the receiving side link channel, wherein the configuration information of the transmission interval includes information indicating the start point of the transmission interval, information indicating the length of the transmission interval, information indicating the bandwidth of the transmission interval, and information indicating the period of the transmission interval.

[0019] The operation method may further include sending second feedback information of the sidelink channel to the transmitting terminal, wherein the second feedback information includes one or more of a Hybrid Automatic Repeat Request (HARQ) response and quality information of the sidelink channel, and the transmitting terminal determines whether to perform a beam update operation based on the second feedback information. The sidelink channel may include a Physical Sidelink Control Channel (PSCCH) and a Physical Sidelink Shared Channel (PSSCH), and the PSCCH may include scheduling information of the PSSCH and triggering information for the beam update operation.

[0020] Furthermore, according to an exemplary embodiment of the present invention, a transmitting terminal performing sidelink communication may include a processor; and a memory storing at least one instruction executable by the processor, wherein, when executed by the processor, the at least one instruction causes the processor to transmit a sidelink signal for beam measurement in all directions using a beam scanning scheme; receive first feedback information of the sidelink signal from a plurality of receiving terminals; and transmit a sidelink channel in a specific direction using a beam of the transmitting terminal determined based on the first feedback information, wherein the transmission area corresponding to the specific direction is narrower than the transmission area corresponding to the all directions.

[0021] Sidelink signals can be transmitted within a beam scanning interval configured by the transmitting terminal and the base station to which they are connected, and the beam scanning interval can be configured within the bandwidth portion (BWP) used for sidelink communication. The transmission interval can be configured based on first feedback information, and the sidelink channel can be transmitted to multiple receiving terminals within the transmission interval using a beam scanning scheme.

[0022] The at least one instruction may also cause the processor to classify multiple receiving terminals into one or more groups based on the locations of multiple receiving terminals identified by the first feedback information, wherein, for each of the one or more groups, the sidelink channel transmits in a beam scanning scheme during the transmission interval.

[0023] The at least one instruction may also cause the processor to send configuration information of the transmission interval to multiple receiving terminals before transmitting the sidelink channel. The configuration information of the transmission interval includes information indicating the start point of the transmission interval, information indicating the length of the transmission interval, information indicating the bandwidth of the transmission interval, information indicating the period of the transmission interval, and identifiers of one or more receiving terminals among the multiple receiving terminals that perform sidelink communication within the transmission interval.

[0024] The at least one instruction may also cause the processor to receive second feedback information about the sidelink channel from multiple receiving terminals; and determine whether to perform a beam update operation based on the second feedback information, wherein the second feedback information includes one or more of a Hybrid Automatic Repeat Request (HARQ) response and quality information of the sidelink channel.

[0025] According to an exemplary embodiment of the present invention, a transmitting terminal may use one or more beams associated with one or more areas where a receiving terminal participating in the multicast service is located to transmit sidelink signals and / or channels. In other words, the transmitting terminal may transmit one or more beams in one or more specific directions rather than in all directions. Therefore, transmission delay in sidelink communication can be reduced, power consumption of the transmitting terminal can be reduced, and interference caused by sidelink communication can be reduced. Thus, the performance of the communication system can be improved. Attached Figure Description

[0026] Figure 1 A conceptual diagram illustrating a V2X communication scenario;

[0027] Figure 2 A conceptual diagram illustrating an exemplary embodiment of a cellular communication system;

[0028] Figure 3 A conceptual diagram illustrating an exemplary embodiment of a communication node constituting a cellular communication system;

[0029] Figure 4 A block diagram illustrating an exemplary embodiment of the user plane protocol stack of a UE performing sidelink communication;

[0030] Figure 5 A block diagram illustrating a first exemplary embodiment of the control plane protocol stack of a UE performing sidelink communication;

[0031] Figure 6 A block diagram illustrating a second exemplary embodiment of the control plane protocol stack of a UE performing sidelink communication;

[0032] Figure 7 A conceptual diagram illustrating a first exemplary embodiment of a side-link communication method performed in a beam scanning scheme;

[0033] Figure 8 A timing diagram illustrating a first exemplary embodiment of beam scanning operation in the time domain;

[0034] Figure 9 A sequence diagram illustrating a first exemplary embodiment of the sidelink multicast communication method;

[0035] Figure 10 A timing diagram illustrating a first exemplary embodiment of the group transmission interval; and

[0036] Figure 11 A timing diagram illustrating a second exemplary embodiment of the group transmission interval. Detailed Implementation

[0037] The following discloses embodiments of the present invention. However, the specific structural and functional details disclosed herein are merely for the purpose of describing embodiments of the invention. Therefore, embodiments of the present invention may be implemented in many alternative forms and should not be construed as limited to the embodiments of the invention set forth herein.

[0038] Therefore, although the invention can have various modifications and alternatives, specific embodiments thereof are shown by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the specific forms disclosed; rather, the invention is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Throughout the description of the drawings, the same reference numerals denote the same elements.

[0039] It should be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element without departing from the scope of the invention, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] It should be understood that when an element is described as "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. Conversely, when an element is described as "directly connected" or "directly coupled" to another element, there are no intermediate elements. Other terms used to describe the relationship between elements should be interpreted in a similar manner (i.e., "between" and "directly between," "adjacent" and "directly adjacent," etc.).

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well. It should be further understood that, when used herein, the terms “comprising,” “including,” and / or “containing” designate the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0042] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should be further understood that terms defined in commonly used dictionaries shall be interpreted as having the same meaning as their meaning in the context of the relevant field and shall not be interpreted as having an idealized or overly formal meaning unless expressly defined herein.

[0043] It should be understood that the terms "vehicle" or "transportation vehicle" or other similar terms as used herein include motor vehicles in general, such as passenger cars including SUVs, buses, trucks, various commercial vehicles, watercraft including various vessels, aircraft, etc., and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other vehicles powered by alternative fuels (e.g., fuels derived from resources other than petroleum). As mentioned herein, a hybrid vehicle is a vehicle with two or more power sources, such as a gasoline-powered vehicle and an electric vehicle.

[0044] Furthermore, it should be understood that one or more of the following methods or aspects may be performed by at least one control unit. The term "control unit" can refer to a hardware device including a memory and a processor. The memory is configured to store program instructions, and the processor is specifically programmed to execute program instructions to perform one or more processes further described below. As described herein, a control unit can control the operation of units, modules, components, etc. Moreover, it should be understood that the following methods may be performed by a device including a control unit in conjunction with one or more other components (e.g., a communication node), as will be understood by those skilled in the art.

[0045] Furthermore, the control unit of the present invention can be implemented as a non-transitory computer-readable medium containing executable program instructions that are executed by a processor, controller, or the like. Examples of computer-readable media include, but are not limited to, ROM, RAM, compressed optical disc (CD)-ROM, magnetic tape, floppy disk, flash drive, smart card, and optical data storage device. The computer-readable recording medium can also be distributed throughout a computer network, enabling program instructions to be stored and executed in a distributed manner, for example, via a telematics server or controller area network (CAN).

[0046] In the following description, embodiments of the invention will be described in more detail with reference to the accompanying drawings. For ease of general understanding in describing the invention, the same parts in the drawings are denoted by the same reference numerals, and repeated descriptions thereof will be omitted.

[0047] Figure 1 This is a conceptual diagram illustrating a V2X communication scenario.

[0048] like Figure 1As shown, V2X communication can include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, vehicle-to-network (V2N) communication, etc. V2X communication can be supported by a cellular communication system (e.g., cellular communication system 140), and V2X communication supported by cellular communication system 140 can be referred to as "cellular-V2X (C-V2X) communication." Specifically, cellular communication system 140 can include 4G communication systems (e.g., LTE communication systems or LTE-A communication systems), 5G communication systems (e.g., NR communication systems), etc.

[0049] V2V communication can include communication between a first vehicle 100 (e.g., a communication node located in vehicle 100) and a second vehicle 110 (e.g., a communication node located in vehicle 110). Various types of driving information, such as speed, heading, time, and location, can be exchanged between vehicles 100 and 110 via V2V communication. For example, autonomous driving (e.g., queuing) can be supported based on the driving information exchanged via V2V communication. V2V communication supported in the cellular communication system 140 can be performed based on "sidelink" communication technologies (e.g., ProSe and D2D communication technologies). Specifically, communication between vehicles 100 and 110 can be performed using at least one sidelink channel established between vehicles 100 and 110.

[0050] V2I communication may include communication between a first vehicle 100 (e.g., a communication node located in vehicle 100) and roadside infrastructure (e.g., a roadside unit (RSU)) 120. Infrastructure 120 may also include traffic lights or streetlights located on the roadside. For example, when performing V2I communication, communication may be performed between a communication node located in the first vehicle 100 and a communication node located in a traffic light. Traffic information, driving information, etc., may be exchanged between the first vehicle 100 and infrastructure 120 via V2I communication. V2I communication supported in the cellular communication system 140 may be performed based on "sidelink" communication technologies (e.g., ProSe and D2D communication technologies). Specifically, communication between vehicle 100 and infrastructure 120 may be performed using at least one sidelink channel established between vehicle 100 and infrastructure 120.

[0051] V2P communication can include communication between a first vehicle 100 (e.g., a communication node located in vehicle 100) and a person 130 (e.g., a communication node carried by person 130). Driving information of the first vehicle 100 and movement information of the person 130, such as speed, heading, time, and location, can be exchanged between vehicle 100 and person 130 via V2P communication. The communication node located in vehicle 100 or the communication node carried by person 130 can generate a hazard warning based on the obtained driving and movement information by identifying dangerous situations. V2P communication supported in the cellular communication system 140 can be performed based on sidelink communication technologies (e.g., ProSe and D2D communication technologies). Specifically, communication between the communication node located in vehicle 100 and the communication node carried by person 130 can be performed using at least one sidelink channel established between the communication nodes.

[0052] V2N communication can be communication between a first vehicle 100 (e.g., a communication node located in vehicle 100) and a server connected via a cellular communication system 140. V2N communication can be performed based on 4G communication technologies (e.g., LTE or LTE-A) or 5G communication technologies (e.g., NR). Alternatively, V2N communication can be performed based on wireless access (WAVE) communication technologies or wireless local area network (WLAN) communication technologies in an in-vehicle environment, with WLAN communication technologies defined in the Wireless Personal Area Network (WPAN) communication technologies defined in IEEE 802.11 or IEEE 802.15.

[0053] Meanwhile, the cellular communication system 140 that supports V2X communication can be configured as follows.

[0054] Figure 2 A conceptual diagram illustrating an exemplary embodiment of a cellular communication system.

[0055] like Figure 2 As shown, a cellular communication system may include an access network, a core network, etc. The access network may include base station 210, relay 220, user equipment (UE) 231 to 236, etc. UE 231 to 236 may include [missing information - likely related to a specific location or component]. Figure 1 The communication nodes in vehicles 100 and 110, located Figure 1 The communication nodes in the infrastructure 120, by Figure 1 The core network may include communication nodes carried by the person 130, etc. When the cellular communication system supports 4G communication technology, the core network may include a Serving Gateway (S-GW) 250, a Packet Data Network (PDN) Gateway (P-GW) 260, a Mobility Management Entity (MME) 270, etc.

[0056] When the cellular communication system supports 5G communication technology, the core network may include User Plane Function (UPF) 250, Session Management Function (SMF) 260, Access and Mobility Management Function (AMF) 270, etc. Alternatively, when the cellular communication system operates in non-standalone (NSA) mode, the core network consisting of S-GW 250, P-GW 260, and MME 270 can support both 5G and 4G communication technologies, or the core network consisting of UPF 250, SMF 260, and AMF 270 can support both 4G and 5G communication technologies.

[0057] Furthermore, when a cellular communication system supports network slicing technology, the core network can be divided into multiple logical network slices. For example, network slices that support V2X communication (e.g., V2V network slices, V2I network slices, V2P network slices, V2N network slices, etc.) can be configured, and V2X communication can be supported via V2X network slices configured in the core network.

[0058] Communication nodes in cellular communication systems (e.g., base stations, relays, UEs, S-GWs, P-GWs, MMEs, UPFs, SMFs, AMFs, etc.) can use at least one of the following communication technologies to perform communication: Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiplexing (OFDM), Filtered OFDM, Single Carrier FDMA (SC-FDMA), Non-Orthogonal Multiple Access (NOMA), Generalized Frequency Division Multiplexing (GFDM), Filter Bank Multicarrier (FBMC), Universal Filtered Multicarrier (UFMC), and Space Division Multiple Access (SDMA).

[0059] Communication nodes in cellular communication systems (e.g., base stations, relays, UEs, S-GWs, P-GWs, MMEs, UPFs, SMFs, AMFs, etc.) can be configured as follows.

[0060] Figure 3 A conceptual diagram illustrating an exemplary embodiment of a communication node constituting a cellular communication system.

[0061] like Figure 3 As shown, the communication node 300 may include at least one processor 310, a memory 320, and a transceiver 330 connected to a network to perform communication. Additionally, the communication node 300 may also include an input interface device 340, an output interface device 350, a storage device 360, etc. Each component included in the communication node 300 can communicate with each other when connected via a bus 370.

[0062] However, each component included in the communication node 300 may be connected to the processor 310 via a separate interface or a separate bus instead of the common bus 370. For example, the processor 310 may be connected to at least one of the memory 320, transceiver 330, input interface device 340, output interface device 350, and storage device 360 ​​via a dedicated interface.

[0063] Processor 310 can execute at least one instruction stored in at least one of memory 320 and storage device 360. Processor 310 may refer to a central processing unit (CPU), graphics processing unit (GPU), or dedicated processor that performs the methods according to embodiments of the present invention thereon. Each of memory 320 and storage device 360 ​​may include at least one of volatile storage medium and non-volatile storage medium. For example, memory 320 may include at least one of read-only memory (ROM) and random access memory (RAM).

[0064] Refer again Figure 2 In the communication system, base station 210 can form macrocells or small cells and can connect to the core network via ideal or non-ideal backhaul. Base station 210 can transmit signals received from the core network to UEs 231 to 236 and relay 220, and can also transmit signals received from UEs 231 to 236 and relay 220 to the core network. UEs 231, 232, 234, 235, and 236 can be within the cellular coverage area of ​​base station 210. UEs 231, 232, 234, 235, and 236 can connect to base station 210 by performing a connection establishment procedure. UEs 231, 232, 234, 235, and 236 can communicate with base station 210 after connecting to it.

[0065] Relay 220 can connect to base station 210 and relay communication between base station 210 and UEs 233 and 234. In other words, relay 220 can transmit signals received from base station 210 to UEs 233 and 234, and can also transmit signals received from UEs 233 and 234 to base station 210. UE 234 can be within the cellular coverage area of ​​both base station 210 and relay 220, and UE 233 can be within the cellular coverage area of ​​relay 220. That is, UE 233 can be located outside the cellular coverage area of ​​base station 210. UEs 233 and 234 can connect to relay 220 by performing a connection establishment procedure. UEs 233 and 234 can communicate with relay 220 after connecting to it.

[0066] Base station 210 and relay 220 can support multiple-input multiple-output (MIMO) technologies (e.g., single-user (SU)-MIMO, multi-user (MU)-MIMO, massive MIMO, etc.), cooperative multipoint (CoMP) communication technologies, carrier aggregation (CA) communication technologies, unlicensed band communication technologies (e.g., licensed assisted access (LAA), enhanced LAA (eLAA), etc.), and sidelink communication technologies (e.g., ProSe communication technologies, D2D communication technologies). UEs 231, 232, 235, and 236 can perform operations corresponding to base station 210 and operations supported by base station 210. UEs 233 and 234 can perform operations corresponding to relay 220 and operations supported by relay 220.

[0067] Specifically, base station 210 can be referred to as Node B (NB), Evolved Node B (eNB), Base Transceiver Station (BTS), Radio Remote Header (RRH), Transmitter Receiver Point (TRP), Radio Unit (RU), Roadside Unit (RSU), Radio Transceiver, Access Point, Access Node, etc. Relay 220 can be referred to as a small base station, Relay Node, etc. Each of UEs 231 to 236 can be referred to as a terminal, Access Terminal, Mobile Terminal, Station, Subscriber Station, Mobile Station, Portable Subscriber Station, Subscriber Station, Node, Device, On-Board Unit (OBU), etc.

[0068] Simultaneously, communication between UE 235 and UE 236 can be performed based on sidelink communication technology. Sidelink communication can be performed using a one-to-one or one-to-many scheme. When performing V2V communication using sidelink communication technology, UE 235 can provide services to UEs located at... Figure 1 The communication node in the first vehicle 100, and UE 236 can be located in Figure 1 The communication node in the second vehicle 110. When performing V2I communication using sidelink communication technology, UE 235 can be located in Figure 1 The communication node in the first vehicle 100, and UE 236 can be located in Figure 1 The communication nodes in infrastructure 120. When performing V2P communication using sidelink communication technology, UE 235 can provide communication nodes located in... Figure 1 The communication node in the first vehicle 100, and UE 236 can be provided by Figure 1 The communication node carried by person 130.

[0069] Scenarios for applying sidelink communication can be categorized based on the location of the UEs participating in the sidelink communication (e.g., UEs 235 and 236) as shown in Table 1 below. For example, Figure 2 The sidelink communication scenario between UE 235 and UE 236 shown can be sidelink communication scenario C.

[0070] Table 1

[0071]

[0072] Meanwhile, the user plane protocol stack of the UE performing sidelink communication (e.g., UE 235 and 236) can be configured as follows.

[0073] Figure 4 A block diagram illustrating an exemplary embodiment of the user plane protocol stack of a UE performing sidelink communication.

[0074] like Figure 4 As shown, the left UE can be Figure 2 The UE 235 shown can be the right UE. Figure 2 The UE 236 shown is used for sidelink communication between UE 235 and UE 236. The scenario for sidelink communication between UE 235 and UE 236 can be one of the sidelink communication scenarios A to D in Table 1. The user plane protocol stack of each of UE 235 and UE 236 may include a physical (PHY) layer, a media access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer.

[0075] Sidelink communication between UE 235 and UE 236 can be performed using a PC5 interface (e.g., a PC5-U interface). Layer-2 identifiers (IDs) (e.g., source Layer-2 ID, destination Layer-2 ID) can be used for sidelink communication, and the Layer-2 ID can be an ID configured for V2X communication (e.g., V2X services). Furthermore, hybrid automatic repeat request (HARQ) feedback operation can be supported in sidelink communication, and RLC acknowledged mode (RLC AM) or RLC unacknowledged mode (RLC UM) can be supported.

[0076] Meanwhile, the control plane protocol stack of the UE performing sidelink communication (e.g., UE 235 and 236) can be configured as follows.

[0077] Figure 5 This is a block diagram illustrating a first exemplary embodiment of the control plane protocol stack of a UE performing sidelink communication. Figure 6 A block diagram illustrating a second embodiment of the control plane protocol stack of a UE performing sidelink communication.

[0078] like Figure 5 and 6 As shown, the left UE can be Figure 2 The UE 235 shown can be the right UE. Figure 2The UE 236 shown is used for sidelink communication between UE 235 and UE 236. The scenario for sidelink communication between UE 235 and UE 236 can be one of the sidelink communication scenarios A to D in Table 1. Figure 5 The control plane protocol stack shown can be a control plane protocol stack used for sending and receiving broadcast information (e.g., Physical Side Link Broadcast Channel (PSBCH)).

[0079] Figure 5 The control plane protocol stack shown may include a PHY layer, a MAC layer, an RLC layer, and a Radio Resource Control (RRC) layer. Sidelink communication between UE 235 and UE 236 can be performed using a PC5 interface (e.g., a PC5-C interface). Figure 6 The control plane protocol stack shown can be a control plane protocol stack used for one-to-one side link communication. Figure 6 The control plane protocol stack shown may include the PHY layer, MAC layer, RLC layer, PDCP layer, and PC5 signaling protocol layer.

[0080] Meanwhile, the channels used in sidelink communication between UE 235 and UE 236 may include the Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Control Channel (PSCCH), Physical Sidelink Discovery Channel (PSDCH), and Physical Sidelink Broadcast Channel (PSBCH). The PSSCH can be used to send and receive sidelink data and can be configured in the UE (e.g., UE 235 or 236) via higher-layer signaling. The PSCCH can be used to send and receive Sidelink Control Information (SCI) and can also be configured in the UE (e.g., UE 235 or 236) via higher-layer signaling.

[0081] PSDCH can be used for discovery procedures. For example, discovery signals can be sent via PSDCH. PSBCH can be used to send and receive broadcast information (e.g., system information). Additionally, demodulation reference signals (DM-RS), synchronization signals, etc., can be used in sidelink communication between UE235 and UE236.

[0082] Meanwhile, the sidelink transmission mode (TM) can be classified into sidelink TM 1 to 4, as shown in Table 2 below.

[0083] Table 2

[0084]

[0085] When sidelink TM 3 or 4 is supported, each of UEs 235 and 236 can use a resource pool configured by base station 210 to perform sidelink communication. A resource pool can be configured for each of the sidelink control information and sidelink data.

[0086] Resource pools for receiving sidelink control information can be configured based on RRC signaling procedures (e.g., dedicated RRC signaling procedures, broadcast RRC signaling procedures). Resource pools for receiving sidelink control information can be configured using broadcast RRC signaling procedures. When sidelink TM 3 is supported, resource pools for sending sidelink control information can be configured using dedicated RRC signaling procedures. Specifically, sidelink control information can be sent using resources scheduled by base station 210 within the resource pool configured by dedicated RRC signaling procedures. When sidelink TM 4 is supported, resource pools for sending sidelink control information can be configured using either dedicated RRC signaling procedures or broadcast RRC signaling procedures. Specifically, sidelink control information can be sent using resources autonomously selected by the UE (e.g., UE 235 or 236) within the resource pool configured by dedicated RRC signaling procedures or broadcast RRC signaling procedures.

[0087] When sidelink TM 3 is supported, a resource pool for transmitting and receiving sidelink data does not need to be configured. Specifically, sidelink data can be transmitted and received via resources scheduled by base station 210. When sidelink TM 4 is supported, a resource pool for transmitting and receiving sidelink data can be configured via a dedicated RRC signaling procedure or a broadcast RRC signaling procedure. Specifically, sidelink data can be transmitted and received via resources autonomously selected by the UE (e.g., UE 235 or 236) within the resource pool configured by the dedicated RRC signaling procedure or the broadcast RRC signaling procedure.

[0088] Next, a method for transmitting and receiving sidelink control information (SCI), including configuration information for transmission and reception, in a V2X-enabled communication system (e.g., a cellular communication system) as described above will be described. Even when a method (e.g., signal transmission or reception) is described to be performed at a first communication node, the corresponding second communication node can also perform a method (e.g., signal reception or transmission) corresponding to the method performed at the first communication node. In other words, when the operation of the first vehicle is described, the corresponding second vehicle can perform an operation corresponding to the operation of the first vehicle. Conversely, when the operation of the second vehicle is described, the corresponding first vehicle can perform an operation corresponding to the operation of the second vehicle. In the embodiments described below, the operation of the vehicle can be the operation of a communication node located within the vehicle.

[0089] Sidelink communication can be performed using high-frequency bands (e.g., millimeter-wave bands). Specifically, sidelink communication can be performed in beam scanning schemes. Therefore, the transmitting terminal can transmit sidelink signals and / or channels in all directions by rotating the beam. Sidelink signals can be synchronization signals (e.g., a synchronization signal / physical broadcast channel (SS / PBCH) block) and reference signals for sidelink communication. For example, reference signals can be Channel State Information Reference Signals (CSI-RS), DM-RS, Phase Tracking Reference Signals (PT-RS), Cell-Specific Reference Signals (CRS), Sounding Reference Signals (SRS), Discovery Reference Signals (DRS), etc. Sidelink channels can be PSSCH, PSCCH, PSDCH, PSBCH, Physical Sidelink Feedback Channel (PSFCH), etc. Additionally, a sidelink channel can refer to a sidelink channel that includes sidelink signals mapped to specific resources in the corresponding sidelink channel. Sidelink communication can support broadcast, multicast, and unicast services.

[0090] In the following exemplary embodiments, sidelink broadcast communication may refer to "sidelink communication performed in a broadcast manner," and sidelink multicast communication may refer to "sidelink communication performed in a multicast manner." Additionally, sidelink multicast communication may refer to "sidelink communication performed in a multicast manner," and sidelink unicast communication may refer to "sidelink communication performed in a unicast manner."

[0091] Figure 7 This is a conceptual diagram illustrating a first exemplary embodiment of a side-link communication method performed in a beam scanning scheme, while Figure 8 This is a timing diagram illustrating a first exemplary embodiment of beam scanning operation in the time domain.

[0092] like Figure 7 and Figure 8 As shown, the transmitting terminal 710 can transmit sidelink signals and / or channels using a beam scanning scheme. For example, the transmitting terminal 710 can use beam #1 in beam interval #1 to transmit sidelink signals and / or sidelink channels, and receive sidelink signals and / or sidelink channels from a receiving terminal (e.g., receiving terminal #1 721) via beam #1 in beam interval #1. Furthermore, the transmitting terminal 710 can use beam #2 in beam interval #2 to transmit sidelink signals and / or sidelink channels, and receive sidelink signals and / or sidelink channels from a receiving terminal via beam #2 in beam interval #2.

[0093] For example, the transmitting terminal 710 can use the beams defined in Table 3 below in beam intervals #1 to #12 to perform sidelink communication with the receiving terminal. The beam scanning intervals including beam intervals #1 to #12 can be configured periodically, and the transmitting terminal 710 can use beams #1 to #12 to perform sidelink communication within the beam scanning interval.

[0094] Table 3

[0095]

[0096] Meanwhile, receiving terminals 721 to 724 can be located in specific areas. For example, receiving terminal #1 721 can be located in an area associated with beam #1 of transmitting terminal 710, receiving terminal #2 722 can be located in an area associated with beam #3 of transmitting terminal 710, receiving terminal #3 723 can be located in an area associated with beam #8 of transmitting terminal 710, and receiving terminal #4 724 can be located in an area associated with beam #9 of transmitting terminal 710. Even when the locations of receiving terminals 721 to 724 are limited to specific areas, transmitting terminal 710 can still use beams #1 to #12 to transmit sidelink signals and / or channels in all directions. Therefore, unnecessary sidelink signals and / or channels can be transmitted through beams #2, #4 to #7, and #10 to #12. Such transmission of unnecessary sidelink signals and / or channels increases transmission delay, power consumption, and interference. To solve this problem, a method is needed to perform sidelink communication using one or more beams associated with one or more specific areas where one or more receiving terminals are located.

[0097] Figure 9 A sequence diagram illustrating a first exemplary embodiment of the sidelink multicast communication method.

[0098] like Figure 9 As shown, the communication system may include a base station (not shown), a transmitting terminal, and receiving terminals #1 to #4. The base station may be... Figure 2 The base station 210 shown can be a transmitting terminal that is Figure 2 The UE 235 shown can have each of the receiving terminals #1 to #4 as follows: Figure 2 The UE 236 shown. Receiving terminals #1 to #4 can be located within or outside the coverage area of ​​the base station. Additionally, the transmitting terminal can be... Figure 7 The transmitting terminal 710 shown, and each of the receiving terminals #1 to #4 can be Figure 7 The receiving terminals shown are #1 to #4 (i.e., 721 to 724). The transmitting and receiving terminals #1 to #4 can be connected with... Figure 3 The communication nodes 300 shown are configured identically or similarly. Transmitting terminals and receiving terminals #1 to #4 can support... Figures 4 to 6The protocol stack shown.

[0099] Transmitting terminals and receiving terminals #1 to #4 can participate in sidelink communication (e.g., sidelink multicast communication). Transmitting terminals and receiving terminals #1 to #4 can connect to the base station and can obtain configuration information for sidelink communication (e.g., sidelink multicast communication configuration information) during the access procedure (e.g., attach procedure) with the base station. The configuration information for sidelink communication may include one or more information elements defined in Table 4 below. Configuration information for sidelink communication can be obtained through a combination of one or more of RRC messages, MAC control elements (CE), and downlink control information (DCI).

[0100] Table 4

[0101]

[0102] The transmitting terminal and receiving terminals #1 to #4 can use the configuration information for sidelink communication received from the base station (e.g., the configuration information shown in Table 4) to perform sidelink communication.

[0103] Sidelink multicast communication can be initiated by one of the terminals (e.g., the transmitting terminal). The transmitting terminal can transmit an SS / PBCH block (or PSDCH, reference signal) in a beam scanning scheme (S901). The SS / PBCH block can be an SS / PBCH block configured for sidelink multicast communication. In step S901, sidelink signals for beam or channel measurement can be transmitted instead of SS / PBCH blocks. For example, synchronization signals (e.g., PSSS, SSSS) or reference signals (e.g., CSI-RS, DRS (e.g., a DRS consisting of PSSS and SSSS)) can be transmitted in step S901.

[0104] In step S901, SS / PBCH blocks can be transmitted within the SL-group bandwidth portion (BWP) configured at the base station. Furthermore, SS / PBCH blocks can be based on a reference... Figure 7 and Figure 8 The beam scanning scheme described is used for transmission. For example, the transmitting terminal may use the corresponding beam (e.g., one of beams #1 to #12) in each of beam intervals #1 to #12 within a beam scanning interval to transmit SS / PBCH blocks. The number of times an SS / PBCH block is repeatedly transmitted within a beam interval can be configured by the base station. An SS / PBCH block may include one or more information elements defined in Table 5 below. One or more information elements configured by the base station (e.g., information elements defined in Table 4) may be included in the SS / PBCH block transmitted from the transmitting terminal.

[0105] Table 5

[0106]

[0107] Receiver terminals #1 to #4 can receive SS / PBCH blocks (or PSDCH, reference signal) from the transmitting terminal by performing monitoring operations within a beam scanning interval (e.g., a beam scanning interval within an SL-group BWP). The beam scanning interval can be pre-configured by the base station via RRC messages, MAC CE, and / or DCI. Receiver terminals #1 to #4 can be receiver terminals participating in sidelink multicast communication. Receiver terminals not participating in sidelink multicast communication may not perform monitoring operations within the beam scanning interval within an SL-group BWP.

[0108] Receiver terminals #1 to #4 can identify information elements included in the SS / PBCH block (e.g., information elements defined in Table 5). Receiver terminals #1 to #4 can identify the quality of a beam or signal (e.g., SS / PBCH block, PDSCH, reference signal) by performing beam measurement operations based on the signal and / or channel received from the transmitting terminal. For example, receiver terminals #1 to #4 can perform beam measurement operations to identify channel state information (CSI), channel quality indicator (CQI), reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-noise ratio (SNR), and / or signal-to-interference-plus-noise ratio (SINR).

[0109] Receiver terminals #1 to #4 can select the beam with the best quality from the transmitter terminals' beams #1 to #12 based on measured quality information. (See again...) Figure 7 Since receiving terminal #1 is located in the region corresponding to beam #1 of transmitting terminal, beam #1 may have the best quality among beams #1 to #12 measured at receiving terminal #1. Therefore, receiving terminal #1 can select beam #1 from beams #1 to #12 of transmitting terminal. Similarly, since receiving terminal #2 is located in the region corresponding to beam #3 of transmitting terminal, the quality of beam #3 may be the best among beams #1 to #12 measured at receiving terminal #2. Therefore, receiving terminal #2 can select beam #1 from beams #3 to #12 of transmitting terminal.

[0110] Since receiving terminal #3 is located in the region corresponding to beam #8 of transmitting terminal, the quality of beam #8 is likely the best among beams #1 to #12 measured at receiving terminal #3. Therefore, receiving terminal #3 can select beam #1 from beams #8 to #12 of transmitting terminal. Since receiving terminal #4 is located in the region corresponding to beam #9 of transmitting terminal, the quality of beam #9 is likely the best among beams #1 to #12 measured at receiving terminal #4. Therefore, receiving terminal #4 can select beam #1 from beams #9 to #12 of transmitting terminal.

[0111] Each of the receiving terminals #1 to #4 can send feedback information including the index of the selected beam to the transmitting terminal (S902). The feedback information may also include beam quality information (e.g., CSI, CQI, RSRP, RSRQ, SNR, SINR, etc.), the identifier of the receiving terminal sending the feedback information, etc. In step S902, the feedback information can be sent to the transmitting terminal using resources (e.g., PSSCH, PSFCH) indicated by the feedback configuration information received from the base station. Alternatively, in step S902, the feedback information can be sent to the transmitting terminal using resources (e.g., PSSCH, PSFCH) indicated by the feedback configuration information contained in the SS / PBCH block received from the transmitting terminal.

[0112] Each of the receiving terminals #1 through #4 may use feedback resources (e.g., resources indicated by feedback configuration information) within the beam interval associated with the selected beam index to notify the transmitting terminal of the corresponding beam index. Receiving terminal #1 may use... Figure 8 The feedback resources in beam spacing #1 (e.g., the feedback resources indicated by the SS / PBCH block received in beam spacing #1) send feedback information including information indicating beam #1 to the transmitting terminal, and the receiving terminal #2 can use it. Figure 8 The feedback resources in the beam spacing #3 shown (e.g., the feedback resources indicated by the SS / PBCH block received in the beam spacing #3) send feedback information, including information indicating beam #3, to the transmitting terminal.

[0113] Receiver terminal #3 can be used Figure 8 The feedback resources in beam spacing #8 (e.g., the feedback resources indicated by the SS / PBCH block received in beam spacing #8) send feedback information including information indicating beam #8 to the transmitting terminal, and the receiving terminal #4 can use... Figure 8 The feedback resource in the beam spacing #9 shown (e.g., the feedback resource indicated by the SS / PBCH block received in the beam spacing #9) sends feedback information including information indicating beam #9 to the transmitting terminal.

[0114] The transmitting terminal can receive feedback information (e.g., beam index, quality information) from the receiving terminals (e.g., receiving terminals #1 to #4). The transmitting terminal can configure one or more groups for sidelink communication based on the feedback information (S903). For example, the transmitting terminal can determine that all receiving terminals that sent feedback information participated in sidelink multicast communication. In response to receiving feedback information from receiving terminals #1 to #4, the transmitting terminal can determine that receiving terminals #1 to #4 participated in sidelink multicast communication and can configure receiving terminals #1 to #4 participating in sidelink multicast communication into one or more groups. The number of groups configured in step S903 can be equal to or less than the number indicated by "Number of Groups" in Table 4 or Table 5, and the number of terminals included in a group configured in step S903 can be equal to or less than the number indicated by "Number of Terminals" in Table 4 or Table 5.

[0115] For example, the transmitting terminal can configure receiving terminals #1 to #4 as a group (hereinafter referred to as "Scenario #1"). Alternatively, the transmitting terminal can configure receiving terminals #1 to #4 into multiple groups based on the location of the receiving terminals (hereinafter referred to as "Scenario #2"). In Scenario #2, the transmitting terminal can configure receiving terminals belonging to the same area into the same group. When the sector area corresponding to the beam of the transmitting terminal is defined as shown in Table 6 below, the transmitting terminal can configure receiving terminals #1 and #2 belonging to sector area #1 as group #1, and receiving terminals #3 and #4 belonging to sector area #3 as group #2.

[0116] Table 6

[0117]

[0118] Upon completion of step S903, the sending terminal can generate control information for sidelink multicast communication (S904). In scenario #1, the control information may include one or more information elements defined in Table 7 below.

[0119] Table 7

[0120]

[0121] In scenario #2, the control information for group #1 may include one or more information elements defined in Table 8 below, and the control information for group #2 may include one or more information elements defined in Table 9 below.

[0122] Table 8

[0123]

[0124] Table 9

[0125]

[0126] In scenario #1, the group sending interval can be configured as follows.

[0127] Figure 10 A timing diagram illustrating a first exemplary embodiment of the group transmission interval.

[0128] like Figure 10 As shown, sidelink multicast communication can be performed between transmitting terminals and receiving terminals #1 to #4 within a group transmission interval. The group transmission interval may include a control resource set (CORESET) and a data channel (e.g., PSSCH). The group transmission interval may include sub-transmission interval #1 for receiving terminal #1, sub-transmission interval #2 for receiving terminal #2, sub-transmission interval #3 for receiving terminal #3, and sub-transmission interval for receiving terminal #4. The sub-transmission intervals for each receiving terminal can be distinguished in the time domain and / or frequency domain. Within each sub-transmission interval, a CORESET (e.g., a control channel) and a data channel can be configured. Alternatively, the sub-transmission intervals for each receiving terminal may not be configured within the group transmission interval.

[0129] The group transmission interval can be configured within the SL-group BWP and can repeat according to a pre-configured period. The start point of the group transmission interval can be indicated by an offset from a pre-configured reference point. The reference point in the frequency domain can be the resource block (RB) #0 of the SL-group BWP or the initial BWP (e.g., subcarrier #0 of common resource block (CRB) #0). The reference point in the time domain can be the start time of time slot #0 or subframe #0.

[0130] The period of a group transmission interval can be one or more time slots, subframes, or radio frames. The length of a group transmission interval can be configured in units of time slots or subframes. The bandwidth of a group transmission interval can be configured in units of RBs or CRBs, and can be equal to or less than the bandwidth of the SL-group BWP.

[0131] In scenario #2, the group sending intervals #1 and #2 can be configured as follows.

[0132] Figure 11 A timing diagram illustrating a second exemplary embodiment of the group transmission interval.

[0133] like Figure 11As shown, sidelink multicast communication can be performed between the transmitting terminal and receiving terminals #1 to #2 belonging to group #1 within group transmission interval #1, and between the transmitting terminal and receiving terminals #3 to #4 belonging to group #2 within group transmission interval #2. Each of group transmission intervals #1 and #2 may include a CORESET (e.g., PSCCH) and a data channel (e.g., PSSCH). Group transmission interval #1 may include a sub-transmission interval #1 for receiving terminal #1 and a sub-transmission interval #2 for receiving terminal #2. Group transmission interval #2 may include a sub-transmission interval #1 for receiving terminal #3 and a sub-transmission interval #2 for receiving terminal #4. The sub-transmission intervals of each receiving terminal can be distinguished in the time domain and / or frequency domain. A CORESET and a data channel can be configured in each sub-transmission interval. Alternatively, the sub-transmission intervals of each receiving terminal may not be configured within group transmission intervals #1 and #2.

[0134] Group transmission intervals #1 and #2 can be configured within the SL-group BWP and can repeat according to a pre-configured period. Group transmission intervals #1 and #2 can be configured continuously or discontinuously. The start point of group transmission intervals #1 and #2 can be indicated by an offset from a pre-configured reference point. The reference point in the frequency domain can be subcarrier #0 of RB#0 (e.g., CRB#0) of the SL-group BWP or the initial BWP. The reference point in the time domain can be the start time of time slot #0 or subframe #0.

[0135] The period of group transmission intervals #1 and #2 can be one or more time slots, subframes, or radio frames. The length of group transmission intervals #1 and #2 can be set in units of time slots or subframes. The bandwidth of group transmission intervals #1 and #2 can be configured in units of RBs or CRBs, and can be less than or equal to the bandwidth of the SL-group BWP.

[0136] Return to reference Figure 9 The transmitting terminal can send the control information set in step S904 to the receiving terminals #1 to #4 (S905). The control information can be sent to the receiving terminals #1 to #4 via one or more of the following: RRC message, MAC CE, and SCI. The control information can be found in Table 3 and... Figure 8 The beam period is defined in the diagram. For example, the transmitting terminal can send control information to the receiving terminal #1 in beam interval #1, to the receiving terminal #2 in beam interval #3, to the receiving terminal #3 in beam interval #8, and to the receiving terminal #4 in beam interval #9. Alternatively, it can be transmitted via... Figure 10 and 11 The group transmission intervals shown are used to send control information.

[0137] Receiving terminals #1 to #4 can receive control information from the sending terminal and can identify the information elements contained in the control information. For example, receiving terminals #1 to #4 can identify the group transmission interval. When step S905 is completed, sidelink multicast communication can be performed within the group transmission interval (S906).

[0138] In scenario #1, the sending terminal can... Figure 10 In the group transmission interval shown, a SCI including scheduling information is transmitted to one or more receiving terminals #1 to #4. The SCI may indicate the PSSCH resources within the group transmission interval. Furthermore, the SCI may also include triggering information for beam update operations. Specifically, the Cyclic Redundancy Check (CRC) of the SCI can be scrambled using an SL-group-RNTI. Each of receiving terminals #1 to #4 can use the SL-group-RNTI to perform a monitoring operation to detect the SCI in the group transmission interval (e.g., the CORESET of the group transmission interval). When an SCI is detected in the group transmission interval, each of receiving terminals #1 to #4 can transmit sidelink data to the transmitting terminal using the PSSCH indicated by the SCI.

[0139] Alternatively, each of receiving terminals #1 through #4 may receive sidelink data from the transmitting terminal via PSSCH indicated by SCI. Each of receiving terminals #1 through #4 may send a HARQ response (e.g., ACK or NACK) to the transmitting terminal regarding the sidelink data. The HARQ response may be sent within the group transmission interval.

[0140] Furthermore, the transmitting terminal may transmit a reference signal to each of the receiving terminals #1 to #4 within the group transmission interval. Each of the receiving terminals #1 to #4 may measure channel quality (e.g., beam quality) based on the reference signal received within the group transmission interval and transmit the measured quality information (e.g., CSI, CQI, RSRP, RSRQ, SNR, SINR, etc.) to the transmitting terminal.

[0141] In scenario #2, the sending terminal can... Figure 11In the group transmission interval #1 shown, SCI#1, including scheduling information, is transmitted to receiving terminals #1 and / or #2. SCI#1 may indicate PSSCH resources within group transmission interval #1. Furthermore, SCI#1 may also include triggering information for beam update operations. Specifically, the CRC of SCI#1 can be scrambled using SL-group-RNTI. Each of receiving terminals #1 and #2 can use SL-group-RNTI to perform a monitoring operation to detect SCI#1 in group transmission interval #1 (e.g., the CORESET of group transmission interval #1). When SCI#1 is detected in group transmission interval #1, each of receiving terminals #1 and #2 can transmit sidelink data to the transmitting terminal using the PSSCH indicated by SCI#1.

[0142] Alternatively, each of receiving terminals #1 and #2 may receive sidelink data from the transmitting terminal via the PSSCH indicated by SCI#1. Each of receiving terminals #1 and #2 may send a HARQ response (e.g., ACK or NACK) to the transmitting terminal for the sidelink data. The HARQ response may be sent within group transmission interval #1.

[0143] Furthermore, the transmitting terminal may transmit a reference signal to each of the receiving terminals #1 and #2 within the group transmission interval #1. Each of the receiving terminals #1 and #2 may measure channel quality (e.g., beam quality) based on the reference signal received within the group transmission interval #1, and transmit the measured quality information (e.g., CSI, CQI, RSRP, RSRQ, SNR, SINR, etc.) to the transmitting terminal.

[0144] In scenario #2, the sending terminal can... Figure 11 In the group transmission interval #1 shown, SCI#2, including scheduling information, is transmitted to receiving terminals #3 and / or #4. SCI#2 may indicate PSSCH resources within group transmission interval #2. Furthermore, SCI#2 may also include triggering information for beam update operations. Specifically, the CRC of SCI#2 can be scrambled using SL-group-RNTI. Each of receiving terminals #3 and #4 can use SL-group-RNTI to perform a monitoring operation to detect SCI#2 in group transmission interval #2 (e.g., the CORESET of group transmission interval #2). When SCI#2 is detected in group transmission interval #2, each of receiving terminals #3 and #4 can transmit sidelink data to the transmitting terminal using the PSSCH indicated by SCI#2.

[0145] Alternatively, each of receiving terminals #3 and #4 may receive sidelink data from the sending terminal via the PSSCH indicated by SCI#2. Each of receiving terminals #3 and #4 may send a HARQ response (e.g., ACK or NACK) to the sending terminal for the sidelink data. The HARQ response may be sent within group transmission interval #2.

[0146] Furthermore, the transmitting terminal may transmit a reference signal to each of the receiving terminals #2 and #4 within the group transmission interval #3. Each of the receiving terminals #3 and #4 may measure channel quality (e.g., beam quality) based on the reference signal received within the group transmission interval #2, and transmit the measured quality information (e.g., CSI, CQI, RSRP, RSRQ, SNR, SINR, etc.) to the transmitting terminal.

[0147] Simultaneously, the transmitting terminal can determine whether to perform a beam update operation based on feedback information (e.g., HARQ response and quality information) received from receiving terminals #1 to #4 (S907). For example, the transmitting terminal can determine that a beam update operation is necessary when one or more of the following conditions are met.

[0148] Condition 1: Number of HARQ-NACKs > Threshold #1

[0149] Condition 2: Channel quality (e.g., CQI) < threshold #2

[0150] Condition 3: The number of receiving terminals with channel quality (e.g., CQI) less than threshold #2 > threshold #3

[0151] In response to the necessity of determining that a beam update operation is required, the transmitting terminal can restart from step S901. Specifically, the group configured in step S903 can be initialized, and the group transmission interval configured in step S904 can be initialized. Accordingly, the transmitting terminal can execute step S901 again after sending a message indicating that the side-link multicast communication has ended.

[0152] Alternatively, the beam update operation can be triggered by receiving terminals #1 to #4. For example, when conditions 1 and / or 2 are met, each of receiving terminals #1 to #4 can send a message requesting the triggering of the beam update operation to the sending terminal. If a message requesting the triggering of the beam update operation is received from one or more of the receiving terminals #1 to #4 participating in the sidelink multicast communication, the sending terminal can again start from step S901.

[0153] Exemplary embodiments of the present invention can be implemented as program instructions executable by various computers and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, or combinations thereof. The program instructions recorded on the computer-readable medium may be specifically designed and configured for the present invention, or may be well-known and available to those skilled in the art of computer software.

[0154] Examples of computer-readable media may include hardware devices such as ROM, RAM, and flash memory, specifically configured to store and execute program instructions. Examples of program instructions include machine code produced by, for example, a compiler, and high-level language code executable by a computer using an interpreter. The above-described exemplary hardware devices may be configured to operate as at least one software module to perform embodiments of the present invention, and vice versa.

[0155] While embodiments of the invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made without departing from the scope of the invention.

Claims

1. A method for a first user equipment (UE), the method comprising the steps of: Receive information transmitted from the base station using multiple synchronization signal / physical broadcast channel (SS / PBCH) blocks for sidelink communication; Based on the information, one or more SS / PBCH blocks are sent in the side link; as well as A reference signal for side link measurement is transmitted in the side link; The number of the one or more SS / PBCH blocks is equal to or less than the number of SS / PBCH blocks transmitted.

2. The method according to claim 1, wherein, The number of SS / PBCH block transmissions is the maximum number of SS / PBCH block transmissions performed by the first UE within a time interval.

3. The method according to claim 1, wherein, The one or more SS / PBCH blocks are transmitted based on a beam scanning scheme, and the one or more SS / PBCH blocks are used for the side link measurement.

4. The method according to claim 1, wherein, Each of the one or more SS / PBCH blocks includes feedback configuration information and receives feedback information from one or more UEs in a resource indicated by the feedback configuration information.

5. The method according to claim 1, further comprising the following step: Receive first feedback information from one or more UEs, the first feedback information including the measurement result of the reference signal; Generate control information for sidelink multicast communication, the control information including an identifier of the second UE among the one or more UEs; The control information is sent to the second UE; as well as The sidelink multicast communication is performed by sending a sidelink channel based on the control information.

6. The method according to claim 5, wherein, The reference signal is transmitted within the beam scanning time interval configured at the base station, and the beam scanning time interval is configured within the bandwidth portion (BWP) for the sidelink communication.

7. The method according to claim 5, wherein, The measurement results include the beam index of the first UE, which is selected based on the beam quality measured from the reference signal.

8. The method according to claim 5, wherein, Configure the transmission interval based on the first feedback information, and transmit the sidelink channel to the one or more UEs in the beam scanning scheme within the transmission interval.

9. The method according to claim 5, further comprising the following step: Receive second feedback information from the sidelink channel from the one or more UEs; as well as Based on the second feedback information, determine whether to perform a beam update operation. The second feedback information includes one or more of a Hybrid Automatic Repeat Request (HARQ) response and quality information for the sidelink channel.

10. The method according to claim 5, wherein, The sidelink channel includes the Physical Sidelink Control Channel (PSCCH) and the Physical Sidelink Shared Channel (PSSCH), and the PSCCH includes the scheduling information of the PSSCH and the triggering information of the beam update operation.

11. A method for a second user equipment (UE), the method comprising the steps of: Receive information transmitted from the base station using multiple synchronization signal / physical broadcast channel (SS / PBCH) blocks for sidelink communication; Based on the information, perform monitoring operations on one or more SS / PBCH blocks in the side link; as well as In the side link, a reference signal for side link measurement is received from the first UE; The number of the one or more SS / PBCH blocks is equal to or less than the number of SS / PBCH blocks transmitted.

12. The method according to claim 11, wherein, The number of SS / PBCH block transmissions is the maximum number of SS / PBCH block transmissions to be sent within a time interval.

13. The method according to claim 11, wherein, The one or more SS / PBCH blocks are transmitted based on a beam scanning scheme, and the one or more SS / PBCH blocks are used for the side link measurement.

14. The method according to claim 11, wherein, Each of the one or more SS / PBCH blocks includes feedback configuration information, and the feedback information of the second UE is transmitted in the resource indicated by the feedback configuration information.

15. The method of claim 11, further comprising the step of: Send first feedback information, including the measurement results of the reference signal, to the first UE; The first UE receives control information for sidelink multicast communication, the control information including the identifier of the second UE; as well as Based on the control information, the first UE receives a sidelink channel for the sidelink multicast communication.

16. The method according to claim 15, wherein, The reference signal is transmitted within the beam scanning time interval configured at the base station, and the beam scanning time interval is configured within the bandwidth portion (BWP) for the sidelink communication.

17. The method according to claim 15, wherein, The measurement results include the beam index of the first UE, which is selected based on the beam quality measured from the reference signal.

18. The method according to claim 15, wherein, Configure the transmission interval based on the first feedback information, and transmit the side link channel in a beam scanning scheme within the transmission interval.

19. The method of claim 15, further comprising the step of: Send the second feedback information of the sidelink channel to the first UE. The second feedback information includes at least one of the Hybrid Automatic Repeat Request (HARQ) response or quality information of the side link channel, and the first UE determines whether to perform a beam update operation based on the second feedback information.

20. The method of claim 15, wherein, The sidelink channel includes the Physical Sidelink Control Channel (PSCCH) and the Physical Sidelink Shared Channel (PSSCH), and the PSCCH includes the scheduling information of the PSSCH and the triggering information of the beam update operation.

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