KR20220148693A - A method and an apparatus for resource allocation by sidelink inter-ue coordination in wireless communication system - Google Patents

Abstract

The present disclosure relates to a communication technique for converging a 5G communication system with IoT technology to support a higher data transfer rate than a 4G system and a system thereof. The present disclosure can be applied to intelligent services (for example, smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, security- and safety-related services, etc.) based on 5G communication technology and IoT-related technology. In addition, the present disclosure proposes a method and apparatus for resource allocation by sidelink inter-UE coordination in a wireless communication system.

Description

A METHOD AND AN APPARATUS FOR RESOURCE ALLOCATION BY SIDELINK INTER-UE COORDINATION IN WIRELESS COMMUNICATION SYSTEM

The present invention relates to a wireless mobile communication system, and in particular, in a process in which a vehicle terminal supporting vehicle-to-everything (V2X) transmits and receives information using a sidelink with another vehicle terminal and a pedestrian portable terminal. It relates to a method and apparatus for performing resource allocation through Inter-UE coordination.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system in order to meet the increasing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a 4G network after (Beyond 4G Network) communication system or an LTE system after (Post LTE) system. In order to achieve a high data rate, the 5G communication system is being considered for implementation in a very high frequency (mmWave) band (eg, such as a 60 gigabyte (60 GHz) band). In order to alleviate the path loss of radio waves and increase the propagation distance of radio waves in the very high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud radio access network: cloud RAN), an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Technology development is underway. In addition, in the 5G system, the advanced coding modulation (ACM) methods FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), and advanced access technologies FBMC (Filter Bank Multi Carrier), NOMA (non orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, in technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication), 5G communication technology is implemented by techniques such as beam forming, MIMO, and array antenna. there will be The application of a cloud radio access network (cloud RAN) as the big data processing technology described above is an example of the convergence of 5G technology and IoT technology.

The present invention relates to a wireless communication system, in a method and apparatus for selecting a transmission resource through cooperation between terminals in a process in which a vehicle terminal supporting V2X exchanges information with another vehicle terminal and a pedestrian portable terminal using a sidelink. it's about Specifically, it relates to a method of exchanging information for inter-UE coordination, a method of allocating sidelink transmission resources through the method, and operations of a base station and a terminal therefor.

The present invention for solving the above problems is a control signal processing method in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting a second control signal generated based on the processing to the base station.

The present invention is to propose a method for inter-UE coordination in sidelink communication and a procedure for the UE to select resources through this method. Through the proposed method, the performance of resource allocation can be improved. In addition, it can be effectively used to minimize the power consumption of the terminal.

1 is a diagram illustrating a communication system to which an embodiment of the present disclosure can be applied.
2 is a diagram illustrating a V2X communication method made through a sidelink according to an embodiment of the present disclosure.
3 is a diagram for explaining a resource pool defined as a set (set) of resources on time and frequency used for sidelink transmission and reception according to an embodiment of the present disclosure.
4 is a diagram illustrating a method for a base station to allocate transmission resources in a sidelink according to an embodiment of the present disclosure.
5 is a diagram illustrating a method in which a terminal directly allocates a sidelink transmission resource through sensing in a sidelink according to an embodiment of the present disclosure.
6 is a diagram illustrating a mapping structure of physical channels mapped to one slot in a sidelink according to an embodiment of the present disclosure.
7 is a diagram illustrating a scenario of performing Inter-UE coordination according to an embodiment of the present disclosure.
8 is a diagram illustrating two methods of cooperation between terminals according to an embodiment of the present disclosure.
9 is a diagram illustrating a sensing window and a resource selection window when (re)selection of a resource is triggered for a terminal performing a Mode 2 operation.
10 is a diagram illustrating an operation in which the terminal-to-terminal cooperation method 1 and the terminal-to-terminal cooperation method 2 are combined according to an embodiment of the present disclosure.
11 is a diagram illustrating an example in which a resource set for transmission of UE-A and a resource set for transmission of UE-B are associated according to an embodiment of the present disclosure.
12A is a diagram illustrating operations of UE-A and UE-B performing inter-terminal cooperation according to an embodiment of the present disclosure.
12B is a diagram illustrating an operation of a terminal for performing cooperation between terminals according to an embodiment of the present disclosure.
13 is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.
14 is a block diagram illustrating an internal structure of a base station according to an embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to more clearly convey the gist of the present disclosure without obscuring the gist of the present disclosure by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present disclosure and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the present disclosure to be complete, and those of ordinary skill in the art to which the present disclosure pertains. It is provided to fully inform the person of the scope of the present disclosure, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible for the instructions stored in the flowchart block(s) to produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in the blocks to occur out of order. For example, it is possible that two blocks shown in succession are actually performed substantially simultaneously, or that the blocks are sometimes performed in the reverse order according to the corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA or ASIC, and '~ unit' performs certain roles. However, '-part' is not limited to software or hardware. '~unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' denotes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card. Also, in an embodiment, '~ unit' may include one or more processors.

In describing the embodiments of the present disclosure in detail, the wireless access network New RAN (NR) on the 5G mobile communication standard initiated by the 3rd generation partnership project long term evolution (3GPP), a mobile communication standard standardization organization, and the packet core as the core network ( 5G System, or 5G Core Network, or NG Core: next generation core), but the main gist of the present disclosure is other communication systems having a similar technical background in a range that does not significantly deviate from the scope of the present disclosure Applicable with slight modifications, which will be possible at the judgment of a person skilled in the art of the present disclosure.

In the 5G system, in order to support network automation, a network data collection and analysis function (NWDAF), which is a network function that provides a function to analyze and provide data collected from a 5G network, may be defined. NWDAF can collect/store/analyze information from the 5G network and provide the result to an unspecified network function (NF), and the analysis result can be used independently in each NF.

For convenience of description below, some terms and names defined in the 3GPP standard (standards of 5G, NR, LTE, or similar systems) may be used. However, the present disclosure is not limited by terms and names, and may be equally applied to systems conforming to other standards.

In addition, a term for identifying an access node used in the following description, a term referring to a network entity, a term referring to messages, a term referring to an interface between network entities, and various identification information Terms and the like referring to them are exemplified for convenience of description. Therefore, it is not limited to the terms used in the present disclosure, and other terms referring to objects having equivalent technical meanings may be used.

Efforts are being made to develop an improved 5G communication system (NR, New Radio) to meet the increasing demand for wireless data traffic after the commercialization of the 4G communication system. In order to achieve high data rates, the 5G communication system is designed to enable resources in the very high frequency (mmWave) band (such as, for example, the 28 GHz frequency band). In order to alleviate the path loss of radio waves and increase the propagation distance of radio waves in the very high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, unlike LTE, the 5G communication system supports various subcarrier spacings such as 15 kHz, 30 kHz, 60 kHz, and 120 kHz, and the Physical Control Channel uses Polar Coding, The data channel (Physical Data Channel) uses LDPC (Low Density Parity Check). In addition, CP-OFDM as well as DFT-S-OFDM are used as a waveform for uplink transmission. In LTE, HARQ (Hybrid ARQ) retransmission in units of TB (Transport Block) is resourced, whereas 5G may additionally support CBG (Code Block Group)-based HARQ retransmission in which a plurality of CBs (Code Blocks) are bundled.

In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud radio access network: cloud RAN), an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, vehicle communication network (V2X (Vehicle to Everything) network), cooperative communication, Coordinated Multi-Points (CoMP), and reception Techniques such as interference cancellation are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication) are being implemented by 5G communication technologies such as beamforming, MIMO, and array antenna. . The application of a cloud radio access network (cloud RAN) as the big data processing technology described above is an example of the convergence 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 such a plurality of services to a user, a method and an apparatus using the same are required to provide each service within the same time period according to the characteristics. . Various services provided in the 5G communication system are being studied, and one of them is a service that satisfies the requirements of low latency and high reliability. In particular, in the case of vehicle communication, in the NR V2X system, unicast communication, groupcast (or multicast) communication, and broadcast communication between the terminal and the terminal are supported. In addition, NR V2X is different from LTE V2X, which aims to transmit and receive basic safety information necessary for vehicle road driving. We aim to provide more advanced services together.

In particular, inter-UE coordination in the sidelink may be considered. Here, the cooperation between terminals may mean providing a more improved sidelink service by sharing information that can be helpful between terminals. In the present invention, information shared for cooperation between terminals is not limited to specific information. As such information, resource allocation information may be included. In general, the terminal performing transmission in the sidelink allocates resources through direct sensing and resource selection procedure (Mode2), or when the terminal performing transmission is within the coverage of the base station, the resource may be allocated from the base station (Mode1) ). However, a method in which the UE receives resource allocation and resource allocation related information from another UE through Inter-UE coordination may be additionally considered. The method of receiving resource allocation and resource allocation related information from another terminal through cooperation between terminals may have the following advantages. First, there are cases in which it is more advantageous to be allocated resources from other terminals. For example, when considering a groupcast scenario, it is better for the leader terminal of the group to directly control the resource allocation of other terminals belonging to the group to provide resource allocation and resource allocation related information to other terminals belonging to the group. It can be advantageous for groupcast operation. In addition, when the terminal performing transmission is located outside the coverage of the base station and the terminal receiving it is located within the coverage of the base station, it is assumed that the base station can better allocate resources to the sidelink terminal by receiving information related to resource allocation from the terminals. , a method in which a terminal within coverage of a base station receives resource allocation information from a base station and transmits it to a terminal outside the coverage of the base station may be considered. In addition, rather than a method in which a terminal performing transmission allocates a resource through a direct sensing and resource selection procedure, a receiving terminal directs the resource allocation location to be received from the transmitting terminal through a direct sensing and resource selection procedure to the transmitting terminal. The method may provide improved resource allocation performance by solving the problems of hidden nodes, exposed nodes, and half duplex. The second reason that it is more advantageous to receive resource allocation from another terminal is that if the terminal performing the transmission is a terminal requiring low power consumption, such as a mobile terminal, power consumption of the terminal is reduced when another terminal performs resource allocation instead. can be minimized. Note that a lot of power may be consumed for the UE to perform sensing to select a sidelink transmission resource. Therefore, in consideration of these advantages, UE and base station operations for sharing resource allocation related information by performing Inter-UE coordination should be defined. Accordingly, the present invention proposes detailed methods for determining how a terminal performing a corresponding operation is determined, what information is required, and indicating resource allocation information in order to perform inter-terminal cooperation.

An embodiment of the present specification is proposed to support the above-described scenario, and in particular, a method for performing Inter-UE coordination in a sidelink, and a method and apparatus for providing resource allocation related information through this. intended to provide

An embodiment of the present specification is proposed to support the above-described scenario, and in particular, it is an object of the present specification to provide a method and an apparatus for performing DRX in a sidelink.

1 is a diagram illustrating a communication system to which an embodiment of the present disclosure can be applied.

Referring to FIG. 1, (a) of FIG. 1 shows an example of a case (In-Coverage, IC) in which all V2X terminals (UE-1 and UE-2) are located within the coverage of the base station. All V2X terminals may receive data and control information from the base station through downlink (DL) or transmit data and control information through uplink (UL) to the base station. In this case, the data and control information may be data and control information for V2X communication. The data and control information may be data and control information for general cellular communication. In addition, V2X terminals may transmit/receive data and control information for V2X communication through a sidelink (SL).

Referring to FIG. 1, (b) of FIG. 1 shows an example of a case in which UE-1 is located within the coverage of the base station and UE-2 is located outside the coverage of the base station among V2X terminals. That is, Figure 1 (b) shows an example of partial coverage (partial coverage, PC) in which some V2X terminals (UE-2) are located outside the coverage of the base station. A V2X terminal (UE-1) located within the coverage of the base station may receive data and control information from the base station through downlink or transmit data and control information through uplink to the base station. A V2X terminal (UE-2) located outside the coverage of the base station cannot receive data and control information from the base station through downlink, and cannot transmit data and control information through uplink to the base station. The V2X terminal UE-2 may transmit/receive data and control information for V2X communication through a sidelink with the V2X terminal UE-1.

Referring to FIG. 1, (c) of FIG. 1 shows an example of a case in which all V2X terminals are located outside the coverage of the base station (out-of coverage, OOC). Therefore, the V2X terminals (UE-1, UE-2) cannot receive data and control information from the base station through the downlink, and cannot transmit data and control information through the uplink to the base station. V2X terminals (UE-1, UE-2) may transmit/receive data and control information for V2X communication through a sidelink.

Referring to FIG. 1, (d) of FIG. 1 shows an example of a scenario in which V2X communication is performed between V2X terminals (UE-1, UE-2) located in different cells. Specifically, (d) of FIG. 1 illustrates a case in which V2X terminals (UE-1, UE-2) are connected to different base stations (RRC connection state) or camping (RRC connection release state, that is, RRC idle state). show At this time, the V2X terminal (UE-1) may be a V2X transmitting terminal and the V2X terminal (UE-2) may be a V2X receiving terminal. Alternatively, the V2X terminal (UE-1) may be a V2X receiving terminal, and the V2X terminal (UE-2) may be a V2X transmitting terminal. The V2X terminal (UE-1) may receive a system information block (SIB) from the base station to which it is connected (or to which it is camping), and the V2X terminal (UE-2) is connected to (or by itself) It can receive SIB from another base station (which is camping). At this time, as the SIB, an existing SIB or a SIB defined separately for V2X may be used. In addition, information on the SIB received by the V2X terminal UE-1 and information on the SIB received by the V2X terminal UE-2 may be different from each other. Therefore, in order to perform V2X communication between terminals (UE-1, UE-2) located in different cells, information is unified or information about this is signaled, and a method of interpreting SIB information transmitted from different cells is additionally required. may be

In FIG. 1, for convenience of explanation, a V2X system composed of V2X terminals (UE-1, UE-2) is illustrated, but communication may be made between more V2X terminals without being limited thereto. In addition, the interface (uplink and downlink) between the base station and the V2X terminals may be named a Uu interface, and the sidelink between the V2X terminals may be named a PC5 interface. Therefore, in the present disclosure, these may be used interchangeably. On the other hand, in the present disclosure, the terminal supports vehicle-to-vehicle communication (vehicular-to-vehicular, V2V), vehicle-to-pedestrian communication (vehicular-to-pedestrian, V2P) supporting vehicle or pedestrian handset (for example, , smartphones), vehicles supporting vehicle-to-network communication (vehicular-to-network, V2N), or vehicles supporting vehicle-to-infrastructure communication (vehicular-to-infrastructure, V2I). have. In addition, in the present disclosure, the terminal may include a road side unit (RSU) equipped with a terminal function, an RSU equipped with a base station function, or an RSU equipped with a part of the base station function and a part of the terminal function.

In addition, according to an embodiment of the present disclosure, the base station may be a base station supporting both V2X communication and general cellular communication, or a base station supporting only V2X communication. In this case, the base station may be a 5G base station (gNB), a 4G base station (eNB), or an RSU. Accordingly, in this disclosure, the base station may be referred to as an RSU.

2 is a diagram illustrating a V2X communication method made through a sidelink according to an embodiment of the present disclosure.

Referring to (a) of Figure 2, UE-1 (201, for example, TX terminal) and UE-2 (202, for example, RX terminal) may perform one-to-one communication, and this It can be called cast (unicast) communication.

Referring to (b) of FIG. 2 , the TX terminal and the RX terminal may perform one-to-many communication, which may be referred to as a groupcast or multicast. In (b) of FIG. 2 , UE-1 211 , UE-2 212 , and UE-3 213 form one group (Group A) to perform groupcast communication. and UE-4 214 , UE-5 215 , UE-6 216 , and UE-7 217 form another group (Group B) to communicate with groupcast (groupcast) can be performed. Each terminal performs groupcast communication only within a group to which it belongs, and communication between different groups may be performed through unicast, groupcast, or broadcast communication. Although it is shown that two groups (Group A, Group B) are formed in (b) of FIG. 2 , the present invention is not limited thereto.

On the other hand, although not shown in Figure 2, V2X terminals can perform broadcast (broadcast) communication. Broadcast communication means a case in which all V2X terminals receive data and control information transmitted by a V2X transmitting terminal through a sidelink. As an example, when it is assumed that UE-1 211 in FIG. 2B is a transmitting terminal for broadcast, all terminals (UE-2 212 , UE-3 213 , UE -4 214 , UE-5 215 , UE-6 216 , and UE-7 217 ) may receive data and control information transmitted by UE-1 211 .

In NR V2X, support of a form in which a vehicle terminal transmits data to only one specific node through unicast and a form in which data is transmitted to a specific number of nodes through a groupcast can be considered, unlike in LTE V2X. For example, these unicast and group cast technologies can be usefully used in service scenarios such as platooning, which is a technology for moving two or more vehicles in a group by connecting them to one network. Specifically, unicast communication may be required for the leader node of a group connected by group driving to control one specific node, and group cast communication may be required for the purpose of simultaneously controlling a group consisting of a number of specific nodes. have.

3 is a diagram for explaining a resource pool defined as a set (set) of resources on time and frequency used for sidelink transmission and reception according to an embodiment of the present disclosure. In the resource pool, a resource granularity of the time axis may be a slot. In addition, the resource allocation unit on the frequency axis may be a sub-channel composed of one or more physical resource blocks (PRBs). In the present disclosure, an example of a case in which the resource pool is non-contiguously allocated in time is described, but the resource pool may be continuously allocated in time. In addition, although the present disclosure describes an example of a case in which a resource pool is continuously allocated on a frequency, a method in which a resource pool is allocated non-contiguously on a frequency is not excluded.

,

,

,...)로 도시 되었다. 301에서 색칠된 부분은 자원 풀에 속한 사이드링크 슬롯들을 나타낸다. 자원 풀에 속한 사이드링크 슬롯들은 비트맵을 통해 자원 풀 정보로 (pre-)configuration될 수 있다. 302를 참조하면, 시간상에서 자원 풀에 속한 사이드링크 슬롯의 셋(집합)이 (

,

,

,...)로 도시 되었다. 본 발명에서 (pre-)configuration의 의미는 단말에 pre-configuration되어 미리 저장되어 있는 설정 정보를 의미할 수도 있고, 단말이 기지국으로부터 cell-common한 방법으로 configuration되는 경우를 의미할 수 도 있다. 여기서 cell-common은 셀안의 단말들이 기지국으로부터 동일한 정보의 설정을 수신함을 의미할 수 있다. 이때, 단말은 기지국으로부터 사이드링크 SL-SIB (sidelink system information block)을 수신하여 cell-common한 정보를 획득하는 방법이 고려될 수 있다. 또한 단말이 기지국과 RRC 연결이 수립된 이후 UE-specific한 방법으로 configuration되는 경우를 의미할 수 도 있다. 여기서 UE-specific은 UE-dedicated라는 용어로 대체될 수 도 있으며 단말마다 특정한 값으로 설정 정보를 수신함을 의미할 수 있다. 이때, 단말은 기지국으로부터 RRC 메시지를 수신하여 UE-specific한 정보를 획득하는 방법이 고려될 수 있다. 또한 (pre-)configuration은 자원 풀 정보로 설정되는 방법과 자원 풀 정보에 설정되지 않는 방법이 고려될 수 있다. 자원 풀 정보로 (pre-)configuration되는 경우는 단말이 기지국과 RRC 연결이 수립된 이후 UE-specific한 방법으로 configuration되는 경우를 제외하고는 해당 자원 풀에서 동작하는 단말들은 모두 공통된 설정 정보로 동작될 수 있다. 하지만 (pre-)configuration이 자원 풀 정보에 설정되지 않는 방법은 기본 적으로 자원 풀 설정 정보와 독립적으로 설정되는 방법이다. 예를 들어, 자원 풀에 하나 이상의 모드가 (pre-)configuration 되고 (예를들어, A, B, 그리고 C) 자원 풀 설정 정보와 독립적으로 (pre-)configuration된 정보가 자원 풀에 (pre-)configuration된 모드 중 어떤 모드를 사용할지 (예를들어, A 또는 B 또는 C)를 지시해 줄 수 있다. Referring to FIG. 3 , a case 301 in which a resource pool is non-contiguously allocated in time is illustrated. Referring to FIG. 3 , a case is shown in which the granularity of resource allocation in time consists of slots. First, a sidelink slot may be defined in a slot used for uplink. Specifically, the length of a symbol used as a sidelink in one slot may be set as sidelink BWP (Bandwidth Part) information. Therefore, among the slots used for the uplink, the slots in which the length of the symbol set for the sidelink is not guaranteed cannot be the sidelink slots. In addition, slots belonging to the resource pool are excluded from slots in which S-SSB (Sidelink Synchronization Signal Block) is transmitted. Referring to 301, except for such slots, a set (set) of slots that can be used as a sidelink in time (

,

,

,...) was shown. Colored parts in 301 indicate sidelink slots belonging to the resource pool. Sidelink slots belonging to the resource pool may be (pre-)configured with resource pool information through a bitmap. Referring to 302, the set (set) of sidelink slots belonging to the resource pool in time (

,

,

,...) was shown. In the present invention, the meaning of (pre-)configuration may mean configuration information pre-configured in the terminal and stored in advance, or may mean a case in which the terminal is configured in a cell-common manner from the base station. Here, cell-common may mean that terminals in a cell receive the same information configuration from the base station. In this case, a method of obtaining cell-common information by receiving a sidelink SL-SIB (sidelink system information block) from the base station may be considered. It may also mean a case in which the terminal is configured in a UE-specific manner after the RRC connection with the base station is established. Here, UE-specific may be replaced with the term UE-dedicated, and may mean that configuration information is received with a specific value for each UE. In this case, a method of obtaining UE-specific information by receiving an RRC message from a base station may be considered. In addition, (pre-)configuration may consider a method set by the resource pool information and a method not set in the resource pool information. In the case of (pre-)configuration with resource pool information, all terminals operating in the resource pool are operated with common configuration information, except when the terminal is configured in a UE-specific manner after RRC connection with the base station is established. can However, the method in which (pre-)configuration is not set in the resource pool information is basically a method that is set independently of the resource pool configuration information. For example, one or more modes are (pre-)configured in the resource pool (eg, A, B, and C), and information that is (pre-)configured independently of the resource pool configuration information is (pre-)configured in the resource pool. ) can indicate which of the configured modes to use (eg, A or B or C).

Referring to 303 in FIG. 3, a case in which a resource pool is continuously allocated on a frequency is illustrated. In the frequency axis, resource allocation may be set with sidelink BWP (Bandwidth Part) information and may be performed in units of sub-channels. A subchannel may be defined as a resource allocation unit on a frequency composed of one or more physical resource blocks (PRBs). That is, a subchannel may be defined as an integer multiple of PRB. Referring to 303, a subchannel may be composed of five consecutive PRBs, and a subchannel size (sizeSubchannel) may be the size of five consecutive PRBs. However, the content shown in the drawings is only an example of the present invention, the size of the subchannel may be set differently, and it is common that one subchannel is configured as a continuous PRB, but it is not necessarily configured as a continuous PRB. A subchannel may be a basic unit of resource allocation for the PSSCH. In 303, startRB-Subchannel may indicate the start position of a subchannel on a frequency in the resource pool. When resource allocation is performed in units of subchannels on the frequency axis, the RB (Resource Block) index (startRB-Subchannel) at which the subchannel starts, information on how many PRBs the subchannel consists of (sizeSubchannel), and the total number of subchannels A resource on a frequency may be allocated through configuration information on (numSubchannel) and the like. In this case, information on startRB-Subchannel, sizeSubchannel, and numSubchannel may be (pre-)configured as resource pool information on frequency.

4 is a diagram illustrating a method for a base station to allocate transmission resources in a sidelink according to an embodiment of the present disclosure.

A method for the base station to allocate transmission resources in the sidelink will be referred to as Mode 1 hereinafter. Mode 1 may be a scheduled resource allocation (scheduled resource allocation). Mode 1 may indicate a method in which the base station allocates resources used for sidelink transmission to RRC-connected terminals in a dedicated scheduling method. The method of Mode 1 can be effective for interference management and resource pool management because the base station can manage sidelink resources.

Referring to FIG. 4 , a transmitting terminal 401 may camp on a base station (cell) 403 ( 405 ). The camp on is, for example, a state in which a terminal in a standby state (RRC_IDLE) can select (or reselect) a base station (cell) as needed and receive system information or paging information. have.

Meanwhile, when the receiving terminal 402 is located within the coverage of the base station (cell) 403 , the receiving terminal 402 may camp on the base station (cell) 403 ( 407 ). On the other hand, when the receiving terminal 402 is located outside the coverage of the base station (cell) 403 , the receiving terminal 402 may not camp on the base station (cell) 403 .

In the present disclosure, the receiving terminal 402 represents a terminal receiving data transmitted by the transmitting terminal 401 .

The transmitting terminal 401 and the receiving terminal 402 may receive a sidelink system information block (SL-SIB) from the base station 403 (410). The SL-SIB information includes sidelink resource pool information for sidelink transmission/reception, parameter setting information for sensing operation, information for setting sidelink synchronization, or a carrier for sidelink transmission/reception operating at different frequencies information may be included.

When data traffic for V2X is generated in the transmitting terminal 401, the transmitting terminal 401 may be RRC-connected to the base station 403 (420). Here, the RRC connection between the terminal and the base station may be referred to as Uu-RRC. The Uu-RRC connection process 420 may be performed before data traffic generation of the transmitting terminal 401 . Also, in Mode 1, in a state in which the Uu-RRC connection process 420 between the base station 403 and the receiving terminal 402 is performed, the transmitting terminal may transmit to the receiving terminal through a sidelink. Contrary to this, in Mode 1, even when the Uu-RRC connection process 420 between the base station 403 and the receiving terminal 402 is not performed, the transmitting terminal may transmit to the receiving terminal through the sidelink.

The transmitting terminal 401 may request a transmission resource capable of performing V2X communication with the receiving terminal 402 from the base station (430). At this time, the transmitting terminal 401 requests the base station 403 for a sidelink transmission resource using an uplink physical uplink control channel (PUCCH), an RRC message, or a medium access control (MAC) control element (CE). can On the other hand, MAC CE may be a buffer status report (BSR) MAC CE of a new format (includes at least an indicator indicating that it is a buffer status report for V2X communication and information on the size of data buffered for D2D communication). have. Also, the transmitting terminal 401 may request a sidelink resource through a scheduling request (SR) bit transmitted through an uplink physical control channel.

Next, the base station 403 may allocate a V2X transmission resource to the transmission terminal 401 . In this case, the base station may allocate transmission resources in a dynamic grant or configured grant method.

First, in the case of the dynamic grant method, the base station may allocate resources for TB transmission through downlink control information (DCI). The sidelink scheduling information included in DCI may include parameters related to transmission time and frequency allocation location information fields of initial transmission and retransmission. DCI for the dynamic grant scheme may be CRC scrambled with SL-V-RNTI to indicate that it is a dynamic grant scheme.

Next, in the case of the configured grant method, the base station may periodically allocate resources for TB transmission by setting a semi-persistent scheduling (SPS) interval through Uu-RRC. In this case, the base station may allocate resources for one TB through DCI. The sidelink scheduling information for one TB included in DCI may include parameters related to transmission time and frequency allocation location information of initial transmission and retransmission resources. When resources are allocated in the configured grant method, the transmission time (occasion) and frequency allocation location of the initial transmission and retransmission for one TB may be determined by the DCI, and the resource for the next TB may be repeated at SPS interval intervals. have. DCI for the configured grant method may be CRC scrambled with SL-SPS-V-RNTI to indicate that it is a configured grant method. In addition, the configured grant (CG) method can be divided into Type1 CG and Type2 CG. In the case of Type2 CG, it is possible to activate / deactivation a resource set as a grant configured through DCI.

Therefore, in the case of Mode 1, the base station 403 may instruct the transmitting terminal 401 to schedule for sidelink communication with the receiving terminal 402 through DCI transmission through a physical downlink control channel (PDCCH) (440).

Specifically, DCI format 3_0 or DCI format 3_1 may be used as downlink control information (DCI) used by the base station 403 for sidelink communication with the transmitting terminal 401 . DCI format 3_0 may be defined as a DCI for scheduling an NR sidelink in one cell, and DCI format 3_1 may be defined as a DCI for scheduling an LTE sidelink in one cell.

In the case of broadcast transmission, the transmitting terminal 401 may perform transmission without the RRC setting 415 for the sidelink. Contrary to this, in the case of unicast or groupcast transmission, the transmitting terminal 401 may perform RRC connection with another terminal on a one-to-one basis. Here, the RRC connection between terminals may be referred to as a PC5-RRC 415 to be distinguished from the Uu-RRC. In the case of groupcast, the PC5-RRC 415 may be individually connected between the terminals in the group and the terminals. Referring to FIG. 4 , although the connection of the PC5-RRC 415 is shown as an operation after the transmission 410 of the SL-SIB, it may be performed at any time before the transmission 410 of the SL-SIB or before the transmission of the SCI.

Next, the transmitting terminal 401 may transmit a 1st stage (SCI) to the receiving terminal 402 through a physical sidelink control channel (PSCCH) (460). Also, the transmitting terminal 401 may transmit a 2nd stage (SCI) to the receiving terminal 402 through the PSSCH ( 470 ). In this case, information related to resource allocation may be included in the 1st stage SCI, and other control information may be included in the 2nd stage SCI. Also, the transmitting terminal 401 may transmit data to the receiving terminal 402 through the PSSCH (480). In this case, 1st stage (SCI), 2nd stage (SCI), and PSSCH may be transmitted together in the same slot.

5 is a diagram illustrating a method in which a terminal directly allocates a sidelink transmission resource through sensing in a sidelink according to an embodiment of the present disclosure.

Hereinafter, a method in which the terminal directly allocates the transmission resource of the sidelink through sensing in the sidelink will be referred to as Mode 2. For Mode 2, it may also be referred to as UE autonomous resource selection. In Mode 2, the base station 503 may provide a sidelink transmission/reception resource pool for V2X as system information, and the transmission terminal 501 may select a transmission resource according to a predetermined rule. Unlike Mode 1 in which the base station directly participates in resource allocation, there is a difference in that the transmitting terminal 501 autonomously selects resources and transmits data based on a resource pool previously received through system information in FIG. 5 .

Referring to FIG. 5 , a transmitting terminal 501 may camp on a base station (cell) 503 ( 505 ). The camp on is, for example, a state in which a terminal in a standby state (RRC_IDLE) can select (or reselect) a base station (cell) as needed and receive system information or paging information. have. 5, in the case of Mode 2, unlike the aforementioned FIG. 4, when the transmitting terminal 501 is located within the coverage of the base station (cell) 503, the transmitting terminal 501 is the base station (cell) You can camp on (503) (507). On the other hand, when the transmitting terminal 501 is located outside the coverage of the base station (cell) 503 , the transmitting terminal 501 may not camp on the base station (cell) 503 .

Meanwhile, when the receiving terminal 502 is located within the coverage of the base station (cell) 503 , the receiving terminal 502 may camp on the base station (cell) 503 ( 507 ). On the other hand, when the receiving terminal 502 is located outside the coverage of the base station (cell) 503 , the receiving terminal 502 may not camp on the base station (cell) 503 .

In the present disclosure, the receiving terminal 502 represents a terminal receiving data transmitted by the transmitting terminal 501 .

The transmitting terminal 501 and the receiving terminal 502 may receive a sidelink system information block (SL-SIB) from the base station 503 (510). The SL-SIB information includes sidelink resource pool information for sidelink transmission/reception, parameter setting information for sensing operation, information for setting sidelink synchronization, or carrier information for sidelink transmission/reception operating at different frequencies. may be included.

The difference between FIG. 4 and FIG. 5 is that in FIG. 4, the base station 503 and the terminal 501 operate in an RRC connected state, whereas in FIG. 5, the terminal operates in an idle mode 520 (RRC connected state). state) can also work. Also, even in the RRC connected state 520 , the base station 503 may allow the transmitting terminal 501 to autonomously select a transmission resource without directly participating in resource allocation. Here, the RRC connection between the terminal 501 and the base station 503 may be referred to as a Uu-RRC 520 . When data traffic for V2X is generated in the transmitting terminal 501, the transmitting terminal 501 sets a resource pool through the system information received from the base station 503, and the transmitting terminal 501 senses within the set resource pool. It is possible to directly select a resource in the time/frequency domain through (530). When a resource is finally selected, the selected resource is determined as a grant for sidelink transmission.

In the case of broadcast transmission, the transmitting terminal 501 may perform transmission without the RRC setting 515 for the sidelink. Contrary to this, in the case of unicast or groupcast transmission, the transmitting terminal 501 may perform RRC connection with another terminal on a one-to-one basis. Here, the RRC connection between terminals may be referred to as a PC5-RRC 515 to be distinguished from the Uu-RRC. In the case of groupcast, the PC5-RRC 515 may be individually connected between the terminal in the group and the terminal. Referring to FIG. 5 , although the connection of the PC5-RRC 515 is illustrated as an operation after the transmission 510 of the SL-SIB, it may be performed at any time before the transmission 510 of the SL-SIB or before the transmission of the SCI.

Next, the transmitting terminal 501 may transmit a 1st stage (SCI) to the receiving terminal 502 through the PSCCH ( 550 ). In addition, the transmitting terminal 401 may transmit a 2nd stage (SCI) to the receiving terminal 402 through the PSSCH (560). In this case, information related to resource allocation may be included in the 1st stage SCI, and other control information may be included in the 2nd stage SCI. Also, the transmitting terminal 501 may transmit data to the receiving terminal 502 through the PSSCH ( 570 ). In this case, 1st stage (SCI), 2nd stage (SCI), and PSSCH may be transmitted together in the same slot.

Specifically, the downlink control information (SCI) used by the transmitting terminals 401 and 501 for sidelink communication to the receiving terminals 402 and 502 may include SCI format 1-A as a first stage (SCI). In addition, there may be SCI format 2-A or SCI format 2-B as a 2nd stage (SCI). In the second stage (SCI), SCI format 2-A includes information for PSSCH decoding when HARQ feedback is not used or when HARQ feedback is used and includes both ACK and NACK information. In contrast, SCI format 2-B may include information for PSSCH decoding when HARQ feedback is not used or when HARQ feedback is used and only NACK information is included. For example, SCI format 2-B may be limitedly used for groupcast transmission.

6 is a diagram illustrating a mapping structure of physical channels mapped to one slot in a sidelink according to an embodiment of the present disclosure.

Specifically, the mapping for PSCCH/PSSCH/PSFCH physical channels is illustrated in FIG. 6 . In the case of the PSFCH, when the HARQ feedback of the sidelink is activated in the upper layer, the resource in time of the PSFCH may be (pre-)configured with resource pool information. Here, the resource in time for transmitting the PSFCH may be (pre-)configured with a value of one of every 0, 1, 2, and 4 slots. Here, '0' means that the PSFCH resource is not used. And 1, 2, and 4 may mean that the PSFCH resource is transmitted in every 1, 2, and 4 slots, respectively. In FIG. 6(a), the structure of a slot in which a PSFCH resource is not configured, and in FIG. 6(b), a structure of a slot in which a PSFCH resource is configured is shown. PSCCH/PSSCH/PSFCH may be allocated to one or more subchannels in terms of frequency. For details on sub-channel allocation, refer to the description of FIG. 3 . Next, referring to FIG. 6 to describe the temporal mapping of PSCCH/PSSCH/PSFCH, one or more symbols before the transmitting terminal transmits PSCCH/PSSCH/PSFCH in the corresponding slot 601 are in the area 602 for AGC. can be used When the corresponding symbol(s) is used for AGC, a method of transmitting a signal of another channel by repeating it in the corresponding symbol region may be considered. In this case, a portion of a PSCCH symbol or a PSSCH symbol may be considered for a signal that is repeated on another channel. Alternatively, the preamble may be transmitted in the AGC area. When the preamble signal is transmitted, there is an advantage that the AGC execution time can be further shortened compared to the method of repeatedly transmitting signals of other channels. When a preamble signal is transmitted for AGC, a specific sequence may be used as the preamble signal 602, and in this case, a sequence such as PSSCH DMRS, PSCCH DMRS, CSI-RS may be used as the preamble. The sequence used as the preamble in the present disclosure is not limited to the above-described example. Additionally, according to FIG. 6, control information related to resource allocation in the early symbols of the slot is transmitted to the PSCCH 603 as 1st stage SCI (sidelink control information), and other control information is 2nd stage SCI, PSSCH region 604 can be transmitted to Data scheduled by the control information may be transmitted to the PSSCH 605 . In this case, the position in time at which the 2nd stage SCI is transmitted may be mapped from the symbol at which the first PSSCH DMRS 606 is transmitted. A position in time at which the PSSCH DMRS 606 is transmitted may be different in a slot in which the PSFCH is transmitted and a slot in which the PSFCH is not transmitted, as shown in FIGS. 6A and 6B . 6A illustrates that a physical sidelink feedback channel (PSFCH 607), which is a physical channel for transmitting feedback information, is located in the last part of a slot. It is possible to secure a predetermined free time (Guard) between the PSSCH 605 and the PSFCH 607 so that a terminal that has transmitted and received the PSSCH 605 can prepare to transmit or receive the PSFCH 607 . . In addition, after transmission and reception of the PSFCH 607 , an empty period (Guard) may be secured for a predetermined time.

The following embodiment is intended to propose a procedure in which a UE performs resource selection in a sidelink in consideration of Inter-UE coordination. First, in the first embodiment, an overall procedure for when and how cooperation between terminals can be performed in the sidelink will be described. The second embodiment proposes methods for performing cooperation between terminals. In the third embodiment, a detailed operation of a terminal providing cooperation information in a first method of performing cooperation between terminals will be described. In the fourth embodiment, a detailed operation of a terminal providing cooperation information in a second method of performing cooperation between terminals will be described. In the fifth embodiment, an operation of a terminal receiving cooperation information between terminals will be described. And, in the sixth embodiment, an overall operation in which a terminal providing cooperation information and a terminal receiving cooperation information perform cooperation between terminals will be described. Note that the following embodiments may be used in combination with each other in the present invention.

<First embodiment>

In the first embodiment, a specific scenario for Inter-UE coordination in the sidelink is presented through drawings. And the overall procedure for how and when cooperation between terminals can be performed is described. Here, the terminal may be a vehicle terminal or a pedestrian terminal.

7 is a diagram illustrating a scenario of performing Inter-UE coordination according to an embodiment of the present disclosure. Here, cooperation between terminals may mean providing an improved sidelink service by sharing information that can be helpful between terminals. In the present invention, information shared for cooperation between terminals is not limited to specific information. As an example, resource allocation information may be included as information shared for cooperation between terminals. In general, when a terminal performing transmission in the sidelink allocates a resource through a direct sensing and resource selection procedure (Mode2), or when a terminal performing transmission is within the coverage of a base station (BS), a resource from the base station Can be assigned (Mode1). However, a method in which the terminal receives resource allocation and resource allocation related information from another terminal through inter-UE coordination may be considered. It has been described above that a situation may arise in which cooperation between terminals is helpful. In the following embodiments including the first embodiment, resource allocation related information will be described as an example, but the contents disclosed in each embodiment may be applied to any information that can be shared for cooperation between terminals.

Referring to FIG. 7 , a scenario in which Inter-UE coordination is performed in a sidelink is illustrated. In FIG. 7 , UE-A 701 corresponds to a terminal providing resource allocation related information to UE-B 702 , and UE-B 702 receives resource allocation related information from UE-A 701 . It corresponds to a terminal performing sidelink transmission. In the example of FIG. 7A , the UE-A 701 providing resource allocation related information corresponds to a terminal receiving the sidelink transmission transmitted by the UE-B 702 . Alternatively, as shown in FIG. 7B , a terminal other than the terminal receiving the sidelink transmission transmitted by the UE-B 702 may also become the UE-A 701 providing resource allocation related information. Specifically, in the example of FIG. 7( b ), the UE-A 701 is not the receiving terminal 703 for the UE-B 702 . Through the cooperation between terminals, UE-B may receive resource allocation related information from UE-A, and may receive help in performing sidelink transmission through this. In the present invention, a terminal providing related information for cooperation between terminals is called UE-A, and a terminal receiving related information for cooperation between terminals is called UE-B. For resource allocation related information that UE-A can provide to UE-B and detailed operations of UE-A therefor, refer to the second to fourth embodiments below. When UE-B receives resource allocation related information from UE-A, refer to the fifth embodiment below for a method for UE-B to utilize it.

As in FIG. 7 , any terminal(s) in the sidelink may be a terminal providing resource allocation information, such as UE-A, or may be a terminal receiving resource allocation information, such as UE-B. It is also noted that it is not necessary for all terminals to be a terminal providing resource allocation information such as UE-A or a terminal receiving resource allocation information such as UE-B. Specifically, one or more terminals may have a qualification to perform the role of UE-A (or UE-B). However, it is not necessary that all terminals having the qualification to perform the role of UE-A (or UE-B) become UE-A (or UE-B). Accordingly, UE-A (or UE-B) may be selected as needed. In other words, the role of UE-A (or UE-B) may be performed without performing the role of UE-A (or UE-B), and conversely, the role of UE-A (or UE-B) may be performed. However, it may not perform the role of UE-A (or UE-B). Therefore, in the embodiment below, conditions that can become UE-A and conditions that can become UE-B when Inter-UE coordination is performed in the sidelink are presented. First, as a condition for becoming UE-A, at least one or more of the following conditions may be included. In the present invention, the condition of becoming UE-A during cooperation between terminals is not limited only to the following conditions.

Conditions to become UE-A when cooperating between terminals

* Condition 1: A certain terminal has the capability to perform inter-terminal cooperation.

** In condition 1, the corresponding capability may mean the ability to provide related information to other terminals during cooperation between terminals. In addition, the terminal having the corresponding capability may report the corresponding capability to a base station (BS) or another terminal. For example, additional terminal processing may be required in order for the terminal to provide resource allocation related information to another terminal through cooperation between terminals as described with reference to FIG. 7 . Therefore, the terminal may perform an operation of reporting the terminal capability of whether to support inter-terminal cooperation to the base station through Uu-RRC or to another terminal through PC5-RRC. Through this, the base station will be able to determine the possibility of cooperation between the terminals by identifying the capability of the corresponding terminal. In addition, through this, the terminal may determine the capability of another terminal, determine whether cooperation between the terminal and the terminal is possible, and determine whether to request resource allocation related information from the terminal.

* Condition 2: Inter-terminal cooperation is enabled for a certain terminal.

** Whether or not (enabling/disabling) between terminals is activated in condition 2 may be (pre-)configured. In this case, (pre-)configuration may be set for each resource pool. Alternatively, it may be determined whether the cooperation between terminals is activated from the upper layer of the terminal. In the present invention, the method for determining whether inter-terminal cooperation is supported is not limited thereto. For example, a method of signaling enable and disable through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also consist of a combination of one or more of the above methods.

* Condition 3: A certain terminal is set to become UE-A in inter-terminal cooperation.

** The condition 3 may be set through (pre-)configuration or it may be determined whether UE-A is from a UE higher layer. In the present invention, the method in which the terminal is configured as UE-A is not limited thereto. For example, a method configured to serve as UE-A through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI), etc. may be considered. It may also consist of a combination of one or more of the above methods.

** The condition 3 may be a case in which a specific terminal is configured as a terminal providing inter-terminal cooperation information in the groupcast. In this case, the corresponding terminal may be a leader terminal of the group.

* Condition 4: A certain terminal is an intended receiving terminal for UE-B.

** According to condition 4 above, only a UE receiving a signal transmitted by UE-B may become UE-A.

* Condition 5: It is determined that a certain terminal has a poor signal reception state for UE-B.

** According to the above condition 5, if the reception state is not good as a result of receiving the signal transmitted by the UE-B, the UE-A may provide information on this to the UE-B. Therefore, condition 5 can be applied together with condition 4. In this case, determining that the reception state of the signal transmitted by the UE-B is not good may be determined by the error rate of the packet or the failure of continuous packet reception. The error rate of the packet may be a more statistical criterion for determining, and the successive packet reception failure may be a case in which X (≥1) packets fail to be received continuously. Here, the packet may mean PSCCH or PSSCH or both PSCCH and PSSCH. When HARQ feedback is used in the sidelink, if UE-A transmits X (≥1) or more NACKs to UE-B, it may be determined that the reception state of the signal to UE-B is not good. In the present invention, a method of determining that a signal reception state for a UE-B is poor by a certain terminal is not limited thereto.

* Condition 6: A certain terminal has sufficient power to perform inter-terminal cooperation.

** The above condition 6 is due to the fact that more power consumption may occur because UE-A must provide related information to UE-B by performing inter-terminal cooperation. Therefore, in Mode2 operation, only the terminal set to full sensing can be limited to UE-A. Alternatively, UE-A may be limited only when the terminal's battery level is higher than a set threshold. In the present invention, the method in which the terminal is configured as UE-A according to the power state is not limited thereto.

* Condition 7: A certain terminal was triggered to provide information for cooperation between terminals.

** In condition 7, the UE is triggered to provide information for inter-terminal cooperation and becomes UE-A when UE-B transmits a signal requesting inter-terminal cooperation information to UE-A and the UE receives it can be Alternatively, a time point at which a specific UE provides information for cooperation between UEs is defined, and when this time comes, the UE may operate as UE-A. In the former case, it may be aperiodic for UE-A to provide inter-terminal cooperation information, and in the latter case, it may be periodic. In the former case, a method in which UE-B requests inter-terminal cooperation information to UE-A through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also consist of a combination of one or more of the above methods.

* Condition 8: A UE has established a unicast link with UE-B.

** According to condition 8 above, cooperation between terminals can be supported only in unicast. When UE-A and UE-B establish PC5-RRC, information exchange between UEs may be performed through PC5-RRC.

Next, as a condition for becoming UE-B, at least one or more of the following conditions may be included. In the present invention, the condition of becoming UE-B during cooperation between terminals is not limited to the following conditions.

Conditions to become UE-B in case of cooperation between terminals

* Condition 1: Inter-terminal cooperation is enabled for a certain terminal.

** Whether or not (enabling/disabling) between terminals is activated in condition 1 may be (pre-)configured. In this case, (pre-)configuration may be set for each resource pool. Alternatively, it may be determined whether the cooperation between terminals is activated from the upper layer of the terminal. In the present invention, the method for determining whether inter-terminal cooperation is supported is not limited thereto. For example, a method of signaling enable and disable through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also consist of a combination of one or more of the above methods.

* Condition 2: A certain terminal is set to become UE-B in inter-terminal cooperation.

** The condition 2 may be set through (pre-)configuration or it may be determined whether UE-B is from a UE higher layer. In the present invention, the method in which the terminal is configured as UE-B is not limited thereto. For example, a method of configuring UE-B through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also consist of a combination of one or more of the above methods.

* Condition 3: A certain terminal does not have sufficient power.

** The condition 3 is due to the fact that the UE-A receives resource allocation information through inter-terminal cooperation and UE-B does not perform sensing for resource selection, thereby reducing power consumption. Therefore, in Mode2 operation, it is possible to limit UE-B to UE-B configured for partial sensing or random selection. Alternatively, the UE-B may be limited only when the terminal's battery level is lower than a set threshold. In the present invention, the method in which the terminal is configured as UE-B according to the power state is not limited thereto.

* Condition 4: A certain terminal cannot perform sensing or has insufficient sensing results.

** A case in which the UE performs sidelink discontinuous reception (DRX) may be considered as a case in which the UE cannot perform sensing in condition 4 or may have an insufficient sensing result. It may be assumed that the UE cannot perform sensing in the DRX inactive period. When UE-B performs sidelink DRX, UE-A needs to transmit information (resource allocation related information) for cooperation between terminals in the DRX active period of UE-B. This is to ensure that UE-B can successfully receive the inter-terminal cooperation information provided by UE-A.

* Condition 5: A UE has established a unicast link with UE-B.

** According to condition 5 above, cooperation between terminals can be supported only in unicast. When UE-A and UE-B establish PC5-RRC, information exchange between UEs may be performed through PC5-RRC.

Next, when Inter-UE coordination is possible in the sidelink and UE-A and UE-B are determined, UE-A provides resource allocation related information to UE-B through inter- UE cooperation As a result, the following method can be considered.

* Method 1: UE-A may receive inter-terminal cooperation information from the base station and provide it to UE-B.

* Method 2: UE-A may directly determine/determine inter-terminal cooperation information and provide it to UE-B.

In the case of method 1, it may be possible when UE-A is within the base station coverage. In addition, information shared from UE-B to UE-A (information that helps the base station to control cooperation between UE-A and UE-B) may be reported to the base station through Uu-RRC. When UE-B is out of base station coverage, it requests inter-terminal cooperation information from UE-A (which may be considered PC5-RRC, sidelink MAC CE, SCI (1 ^st SCI or 2 ^nd SCI), etc.), and the UE -A may request inter-terminal cooperation information (resource allocation information) for UE-B from the base station (this may be considered Uu-RRC, Uu MAC CE, etc.). When UE-A receives inter-terminal cooperation information for UE-B from the base station, this information may be provided to UE-B as it is, or information determined by UE-A by referring to this information may be provided to UE-B . On the other hand, in the case of method 2, since UE-A directly determines/determines cooperation information between terminals and provides it to UE-B, it can be supported regardless of the location of UE-A (either within the coverage of the base station or outside the coverage of the base station). have. A method of determining/indicating cooperation information between terminals when method 2 is supported in the embodiments below will be described in more detail. Information exchange for inter-UE coordination in the sidelink between the UE and the UE may be made through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI). It may also consist of a combination of one or more of the above methods. In the present invention, the method of indicating information for performing cooperation between terminals is not limited thereto.

<Second embodiment>

In the second embodiment, details are provided when UE-A provides resource allocation related information to UE-B as information on inter-UE coordination in the sidelink. Here, the terminal may be a vehicle terminal and a pedestrian terminal. The following two methods may be considered as a cooperative method between UEs in which UE-A provides resource allocation related information to UE-B. In the present invention, the method of cooperation between terminals is not limited to the following method.

How to cooperate between terminals

* Method 1: UE-A transmits a set of time-frequency resource allocation for transmission of UE-B as inter-terminal cooperation information.

** In the method 1, the set of time-frequency resource allocation for UE-B transmission may be resource allocation information selected for (re)transmission of one or more TB (Transport Block). In addition, the set of resource allocation selected at this time may be resource allocation information suitable (preferred) or inappropriate (non-preferred) for transmission of UE-B. In addition, the selected set of resource allocation may include both resources suitable for transmission of UE-B and resources not suitable for transmission. For detailed operation of the terminal with respect to the method 1, refer to the fourth embodiment below.

** In the method 1 above, the UE-A provides information on whether the set of resource allocation selected for transmission of UE-B is suitable (preferred) or inappropriate (non-preferred) resource allocation information for transmission of UE-B. It can be indicated using 1-bit information with -B. The indication of the corresponding information may be made through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI). It may also consist of a combination of one or more of the above methods. The method of indicating corresponding information in the present invention is not limited thereto.

* Method 2: UE-A transmits whether there is a resource conflict with respect to resource allocation information indicated by UE-B by SCI as inter-terminal cooperation information.

** In the method 2, whether there is a resource collision in the resource allocation information indicated by the UE-B through the SCI may be a resource collision detected by the UE-A. Or, it may be whether there is a conflict of expected or potential resources. Alternatively, it may include both whether the resource collides detected by UE-A and whether the expected/potential resource collides. Also, in Method 2, the existence of resource collision may be interpreted as whether the resource allocation information indicated by the UE-B by SCI is inappropriate (non-preferred). For detailed operation of the terminal for method 2, refer to the third embodiment below.

8 is a diagram illustrating two methods of cooperation between terminals according to an embodiment of the present disclosure. According to Inter-Terminal Cooperation Method 1 801, UE-A provides UE-B with set information 803 of time-frequency resource allocation suitable (preferred) or inappropriate (non-preferred) for transmission to UE-B. can give On the other hand, according to the inter-terminal cooperation method 2 802 , UE-A may provide UE-B only whether the resource reserved by UE-B through SCI is suitable. In case of inter-terminal cooperation method 1, since UE-A has to signal the set information 803 of time-frequency resource allocation to UE-B, signaling overhead may be increased compared to inter-terminal cooperation method 2. In the case of the inter-terminal cooperation method 2, since the UE-A signals to the UE-B only whether the resource reserved by the UE-B through the SCI is appropriate, the UE-B may indicate the suitability with 1-bit information.

In the sidelink, only one of method 1 and method 2 for inter-terminal cooperation may be supported, or both methods may be supported. When both methods are supported, the terminal needs to select one of the two methods to operate. In the following embodiment, conditions under which method 1 and method 2 can be selected when both method 1 and method 2 are supported between terminals are presented. First, as a condition for selecting the inter-terminal cooperation method 1, at least one of the following conditions may be included. The present invention is not limited only to the conditions set forth below.

Conditions under which the terminal-to-device cooperation method 1 operates

* Condition 1: UE-A is set to operate as Inter-Terminal Cooperation Method 1.

** The condition 1 may be set through (pre-)configuration or it may be determined whether the UE-to-device cooperation method 1 is from a UE upper layer. In the present invention, the method set as method 1 for cooperation between terminals is not limited thereto. For example, a method configured as the inter-terminal cooperation method 1 through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also consist of a combination of one or more of the above methods.

* Condition 2: UE-A has sufficient power to perform inter-terminal cooperation.

** In condition 2, an additional sensing operation is performed for UE-A when operating in inter-terminal cooperation method 1, and no additional sensing operation is performed when UE-A operates in inter-terminal cooperation method 2 It is based on the assumption that consumption can be reduced. Therefore, it is possible to limit the terminal set to full sensing in Mode2 operation to operating in the inter-terminal cooperation method 1. Alternatively, it may be limited to operating as method 1 for cooperation between terminals only when the battery level of the terminal is higher than a set threshold value. In the present invention, the method in which the cooperative method between the terminals is determined according to the power state of the terminal is not limited thereto.

* Condition 3: UE-A has established a unicast link with UE-B.

** According to condition 3, inter-terminal cooperation method 1 may be supported only in unicast. In the case of Inter-Terminal Cooperation Method 1, UE-A needs to be provided with prior information such as UE-B's traffic-related requirements from UE-B. When UE-A and UE-B establish PC5-RRC, information exchange between UEs may be performed through PC5-RRC.

Next, at least one or more of the following conditions may be included as a condition for selecting the inter-terminal cooperation method 2 . The present invention is not limited only to the conditions set forth below.

Conditions under which the terminal-to-device cooperation method 2 operates

* Condition 1: UE-A is set to operate in Inter-Terminal Cooperation Method 2.

** The condition 1 may be set through (pre-)configuration or it may be determined whether the UE-to-device cooperation method 2 is from an upper layer of the UE. In the present invention, the method set as the inter-terminal cooperation method 2 is not limited thereto. For example, a method configured as Inter-Terminal Cooperation Method 2 through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also consist of a combination of one or more of the above methods.

* Condition 2: UE-A does not have sufficient power.

** In condition 2, an additional sensing operation is performed for UE-A when operating in inter-terminal cooperation method 1, and no additional sensing operation is performed when UE-A operates in inter-terminal cooperation method 2 It is based on the assumption that consumption can be reduced. Therefore, it is possible to limit the terminal set to partial sensing or random selection in Mode2 operation to operating in the inter-terminal cooperation method 2. Alternatively, it may be limited to operating in the cooperative method 2 between terminals only when the battery level of the terminal is lower than a set threshold value. In the present invention, the method in which the cooperative method between the terminals is determined according to the power state of the terminal is not limited thereto.

* Condition 3: UE-A has received SCI from UE-B.

** Unlike method 1 for cooperation between terminals in condition 3 above, in method 2 for cooperation between terminals, UE-A receives SCI (1 ^st SCI, in other words, PSCCH) from UE-B and grasps resource information reserved by UE-B Only then can the suitability be judged.

* Condition 4: UE-A cannot perform resource selection for transmission of UE-B.

** The condition 4 may correspond to a case in which UE-A cannot operate in the inter-terminal cooperation method 1. For example, even if UE-A selects a resource through UE-A cooperation method 1 due to a delay time occurring in cooperation between terminals, a case may occur in which the corresponding information is no longer valid.

The conditions for UE-A to select one of the two methods are presented above when method 1 and method 2 are supported between terminals in the sidelink. However, when UE-A can use both method 1 and method 2 between UEs, it may be determined that the UE directly selects one of the two methods without determining the determination based on the above conditions. This can be interpreted as a terminal implementation. In addition, UE-A may signal to UE-B which method has been selected among the inter-terminal cooperation method 1 and method 2. An indication of which method the UE-A has selected among the inter-terminal cooperation method 1 and method 2 may be possible with 1-bit information, and signaling for this is PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) ) and so on. It may also consist of a combination of one or more of the above methods. In the present invention, the method of indicating information on which method the UE-A has selected among the inter-terminal cooperation method 1 and method 2 is not limited thereto.

<Third embodiment>

In the third embodiment, a detailed operation of the terminal with respect to the method 2 of cooperating between terminals of the sidelink described in the second embodiment will be described. Specifically, a method for UE-A to determine and identify that a resource occupied by UE-B through SCI is not suitable for transmission when the inter-terminal cooperation method 2 is used will be described. Here, the terminal may be a vehicle terminal and a pedestrian terminal.

According to the sidelink inter-terminal cooperation method 2, UE-A transmits, as inter-terminal cooperation information, whether there is a resource collision with respect to resource allocation information indicated by UE-B through SCI. In this case, whether there is a resource collision in the resource allocation information indicated by the UE-B by the SCI may be a resource collision detected by the UE-A. Or, it may be whether there is a conflict of expected or potential resources. Here, whether the resource collision detected by UE-A and the expected/potential resource collision may be interpreted as inappropriate (non-preferred) resource allocation information indicated by UE-B through SCI. The present invention is not limited to such an analysis. Note that other similar interpretations are possible. In the case of the inter-terminal cooperation method 2, since the UE-A signals to the UE-B only whether the resource reserved by the UE-B through the SCI is appropriate, the UE-B may indicate the suitability with 1-bit information. UE-A determines that the resource allocation information indicated by UE-B by SCI is inappropriate (non-preferred), and at least one of the following pieces of information may be considered. The present invention is not limited to the information presented below.

Information for determining that resource allocation information of UE-B is inappropriate in Inter-Terminal Cooperation Method 2

* Information 1: UE-A's reception state of a signal to UE-B

** In the above information 1, when UE-A determines that the reception state of a signal transmitted by UE-B is not good, it may be determined as a packet error rate or continuous packet reception failure. The error rate of a packet may be a statistical determination criterion, and the successive packet reception failure may be a case in which X (≥1) packets fail to be received continuously. Here, the packet may mean PSCCH or PSSCH or both PSCCH and PSSCH. In the present invention, a method of determining that a signal reception state for a UE-B is poor by a certain terminal is not limited thereto.

* Information 2: Result for UE-A to perform sensing

** In the above information 2, sensing by UE-A may mean SCI (1 ^st SCI, in other words, PSCCH) decoding and SL RSRP (Sidelink Reference Signal Received Power) measurement. Both SCI decoding and SL RSRP measurement may be included, or only one of them may be included. UE-A may determine whether a resource reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH) is suitable through sensing.

* Information 3: Resource information selected by UE-A for its NR sidelink transmission

** According to information 3 above, if the resource information selected by UE-A for its NR sidelink transmission overlaps in time and frequency with the resource reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH), half Since transmission and reception cannot be performed at the same time due to duplex, it is possible to determine whether the resource reserved by the UE-B through SCI is appropriate through information 3.

** According to information 3, the resource information selected by UE-A for its NR sidelink transmission may mean a set of time-frequency resource allocation selected for (re)transmission of one or more TB (Transport Block). .

** According to information 3 above, the resource information selected by UE-A for its NR sidelink transmission may include all of a set of time-frequency resource allocations selected for (re)transmission of one or more TB (Transport Block). and may include only a subset of them. When only a subset is included, the subset may be limited to only the initial transmission resource. This may be because determining whether the initial transmission resource is inappropriate is more important than the retransmission resource.

* Information 4: Set information of time-frequency resource allocation selected by UE-A for another UE-B

** According to information 4 above, the set information of time-frequency resource allocation selected by UE-A for another UE-B is the resource and time reserved by UE-B through SCI (1 ^st SCI, in other words PSCCH) and If the frequency overlaps, reception from different UE-Bs cannot be expected at the same time, so through information 4, it can be determined whether the resource reserved by the UE-B through SCI is appropriate.

* Information 5: UE-A is scheduled or configured resource information for UL transmission

** According to information 5 above, if resource information scheduled or configured for UL transmission by UE-A overlaps with resources reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH) in time and frequency, half duplex Since transmission and reception cannot be performed at the same time due to , it is possible to determine whether the resource reserved by the UE-B through SCI is appropriate through information 5.

* Information 6: LTE sidelink transmission/reception information of UE-A

** According to information 6 above, when the resource allocation information for LTE sidelink transmission and reception of UE-A overlaps with the resource reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH) in time and frequency, it is half duplex. Due to the fact that simultaneous transmission and reception cannot be performed or resource collision can be expected, it is possible to determine whether the resource reserved by UE-B through SCI is suitable through information 6 .

* Information 7: PSFCH transmission/reception information of UE-A

** According to information 7 above, since PSFCH transmission and reception is determined by the location of a resource allocated for PSSCH transmission, the time and frequency resource location of the PSSCH resource reserved by the UE-B through SCI (1 ^st SCI, in other words, PSCCH) may be determined not to be suitable for PSFCH transmission/reception, and thus, through information 7, it may be determined whether a resource reserved by UE-B through SCI is suitable.

* Information 8: Inter-terminal cooperation information received by UE-A from another UE

** According to information 8 above, when UE-A receives appropriate (preferred) or inappropriate (non-preferred) resource allocation related information from another UE, the resource allocation information determined ^therefrom is In case of overlap in time and frequency with the resource reserved through SCI (in other words, PSCCH), simultaneous transmission and reception due to half duplex or resource collision may be expected. It can be determined whether this is appropriate.

* Information 9: Location information provided by UE-A from UE-B or other terminals

** Even when resource collision is expected for resources reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH) according to information 9 above, it is expected that interference is small if the distance is long according to the location information Therefore, through information 9, it is possible to determine whether the resource reserved by the UE-B through SCI is appropriate.

* Information 10: information on whether UE-B can use inter-terminal cooperation information

** In the case of information 10, even when resource collision is expected for a resource reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH) according to information 10, UE-B is inter-terminal by information 10 When the cooperation information is not available, UE-A may not provide inter-terminal cooperation information to UE-B. Whether the UE-B can use the inter-terminal cooperation information is related to the determination of the UE-B, and refer to the condition of becoming UE-B during inter-terminal cooperation of the first embodiment.

It is noted that information for determining that the resource allocation information of UE-B is inappropriate in method 2 for cooperation between terminals presented above may also be used in method 1 for cooperation between terminals. For details on this, refer to the fourth embodiment.

<Fourth embodiment>

In the fourth embodiment, a detailed operation of the terminal with respect to the method 1 of cooperation between terminals of the sidelink described in the second embodiment will be described. In detail, a method in which UE-A selects a preferred transmission resource of UE-B through sensing when inter-terminal cooperation method 1 is used will be described. Here, the terminal may be a vehicle terminal and a pedestrian terminal.

First, a Mode2 operation in which a general terminal selects a transmission resource through sensing may be performed through seven steps as shown in Table 1 below. When the (re)selection of a resource in slot 'n' is triggered when the terminal performs the Mode2 operation, the sensing window and the resource selection window refer to FIG. 9 . 9 is a diagram illustrating a sensing window and a resource selection window when (re)selection of a resource is triggered for a terminal performing a Mode 2 operation.

[Table 1] 7 steps in which the terminal selects a transmission resource through sensing

를 파악한다. 단말은 단계 2)에서 도 9에 도시된 바와 같이 sensing window (902)안에서 SCI 디코딩과 SL RSRP (Sidelink Reference Signal Received Power) 측정을 통해, 사이드링크 전송으로 인해 모니터링 하지 못한 슬롯을 제외하고 모니터링(센싱)을 수행한다. 이 때 SCI 디코딩은 PSSCH 디코딩과 동일한 의미를 가지며 SCI 디코딩을 통해 다른 단말이 점유한 자원 할당 정보를 파악할 수 있다. 단말은 단계 3)에서 RSRP 임계값(

)을 설정하며 이때 RSRP 임계 값은 단말의 자원선택에 대한 priority 값(

)과 수신한 SCI의 priority 값(

)의 함수로 결정될 수 있다. 단말은 단계 4)에서 후보 자원의 세트

을 단계 1)에서 파악한 선택 가능한 모든 후보 자원으로 초기화 한다. 단말은 단계 5)에서 단계 2)에서 사이드링크 전송으로 인해 모니터링 하지 못한 슬롯이 존재하는 경우, 해당 슬롯에 대해 상위 레이어로 설정된 sl-ResourceReservePeriodList내에 있는 모든 Resource reservation period를 반영하여 해당 자원이 후보 자원의 세트

내의 자원과 중첩(overlap)되는 경우 해당 자원을

에서 배제한다. 단말은 단계 6)에서, 단계 2)에서 모니터링(센싱)을 수행한 슬롯에 대해 SCI가 디코딩 되고 SCI 디코딩을 통해 다른 단말이 점유한 자원 할당 정보가 해당 자원이 후보 자원의 세트

내의 자원과 중첩(overlap)되는 경우 그리고 측정된 SL RSRP 가 RSRP 임계 값보다 높은 경우에 해당 자원을

에서 배제한다. 마지막으로 단말은 단계 7)에서 후보 자원의 세트

내의 남이 있는 자원의 수가

보다 작은 경우에 RSRP 임계 값을 3dB 증가시키고 단계 4)-7)을 반복한다.

내의 남이 있는 자원의 수가

이상이 되면 단말은

를 단말 상위로 보고한다. 보다 상세한 내용은 표 1를 참고한다. According to Table 1, the terminal in step 1) as shown in FIG. 9, the total number of selectable candidate resources in the resource selection window 901

figure out In step 2), as shown in FIG. 9, the terminal performs SCI decoding and SL RSRP (Sidelink Reference Signal Received Power) measurement in the sensing window 902 to monitor (sensing) except for slots that are not monitored due to sidelink transmission. ) is performed. At this time, SCI decoding has the same meaning as PSSCH decoding, and resource allocation information occupied by other terminals can be identified through SCI decoding. The terminal in step 3) the RSRP threshold (

), and at this time, the RSRP threshold is the priority value (

) and the received SCI priority value (

) can be determined as a function of The terminal sets the candidate resource in step 4)

is initialized with all selectable candidate resources identified in step 1). If there is a slot that cannot be monitored due to sidelink transmission in step 5) to step 2) in step 2), the UE reflects all resource reservation periods in the sl-ResourceReservePeriodList set as a higher layer for the slot, so that the corresponding resource is the candidate resource. set

If it overlaps with a resource within

excluded from In step 6), in step 2), SCI is decoded for the slot for which monitoring (sensing) is performed, and resource allocation information occupied by another terminal through SCI decoding is determined that the corresponding resource is a set of candidate resources.

If it overlaps with a resource within and the measured SL RSRP is higher than the RSRP threshold, the resource

excluded from Finally, the UE sets the candidate resource in step 7)

The number of resources remaining within

If it is less than, increase the RSRP threshold by 3 dB and repeat steps 4)-7).

The number of resources remaining within

In case of abnormality, the terminal

is reported to the top of the terminal. For more details, see Table 1.

When UE-A selects a preferred transmission resource of UE-B through sensing using Inter-Terminal Cooperation Method 1, the Mode2 resource selection steps shown in Table 1 and FIG. 9 may be reused. However, unlike the general Mode2 operation described with reference to Table 1 and FIG. 9, when UE-A selects a resource for UE-B transmission through UE-A cooperation method 1, in Mode2 operation through Table 1 and FIG. 9 An operation according to at least one of the following operations or a combination thereof may vary. The present invention is not limited to the variants presented below.

Modification of Mode2 operation when Inter-Terminal Cooperation Method 1 is used

* Operation 1: The resource selection window 901 in step 1) in Table 1 may be determined as [n+T _X , n+T ₂ ]. Here, T _X may be determined by the following conditions.

** T _X =T ₁ if T _d < T ₁

** T _X =T _d if T _d ≥T ₁

** T _d is a value defined as a value in which the delay generated for performing inter-terminal cooperation in the sidelink is reflected, and may be set through an upper layer or a fixed value. Here, T _d may be set in units of slots or ms. However, the present disclosure does not limit the value set as T _d to a specific value.

* Operation 2: In step 3) in Table 1, the RSRP threshold value may be set independently of the threshold value set in the general Mode2 operation when the inter-terminal cooperation method 1 is used, or may be set by applying an offset value.

내서 배제하는 단계로 대체될 수 있다. * Operation 3: In Table 1, step 5) is skipped or UE-B is determined by information for determining suitability of resource allocation information of UE-B in method 2 for inter-terminal cooperation presented through the third embodiment. The resource(s) for which the resource allocation information indicated by the SCI is determined to be inappropriate (non-preferred), the resource is a set of candidate resources

It can be replaced by the step of excluding from within.

** If step 5) is skipped in operation 3, since the resource excluded in step 5) of Table 1 is not a resource excluded through sensing unlike step 6), suitable (preferred) or This is because the resource allocation information determined to be inappropriate (non-preferred) may not be suitable.

내서 배제하는 동작은 단말 간 협력 방법 1과 단말 간 협력 방법 2가 결합된 동작으로 해석할 수도 있다. 이와 달리, 해당 동작은 단말 간 협력 방법 2와 독립적인 것으로 해석될 수도 있다.** In operation 3, it is determined that the resource allocation information indicated by the UE-B by SCI is inappropriate (non-preferred) by the information for determining the suitability of the resource allocation information of the UE-B in the inter-terminal cooperation method 2 A set of resource(s) for which that resource is a candidate resource

The operation to exclude from within may be interpreted as an operation in which the inter-terminal cooperation method 1 and the inter-terminal cooperation method 2 are combined. Alternatively, the corresponding operation may be interpreted as being independent of the method 2 for cooperation between terminals.

에서 배제하는 동작으로 수행될 수 있을 것이다. 그리고 (1003)에서 UE-A는 단말 간 협력 방법 1를 통해 UE-B의 전송을 위한 시간-주파수 자원 할당의 세트를 선택할 수 있을 것이다.When inter-terminal cooperation is performed and UE-A provides (preferred) resource allocation information suitable for transmission of UE-B, FIG. 10 shows inter-terminal cooperation method 1 and inter-terminal cooperation method according to an embodiment of the present disclosure 2 is a diagram showing the combined operation. When inter-terminal cooperation is performed and UE-A uses inter-terminal cooperation method 2, as shown in ( 1001 ) of FIG. Whether or not is transmitted as cooperation information between terminals. Here, the existence of a resource collision may be interpreted as whether the UE-B's resource allocation information is appropriate. In addition, UE-A may provide UE-B with 1-bit information only whether the resource reserved by UE-B is appropriate. On the other hand, when UE-A uses the inter-terminal cooperation method 1, the combined operation of the inter-terminal cooperation method 2 may be considered, and the operations of ( 1001 ) to ( 1003 ) of FIG. 10 may be considered together. As described above, (1001) means inter-terminal cooperation method 2, and when inter-terminal cooperation method 1 is used in (1002), as in operation 3 of a modification of the Mode2 operation, step 5) in Table 1 is the third Resources for which resource allocation information indicated by SCI by UE-B is determined to be inappropriate (non-preferred) by information for determining suitability of resource allocation information of UE-B in method 2 for cooperation between terminals presented through the embodiment A set of candidate resource(s) for that resource

It may be performed as an operation to exclude from And in 1003, UE-A may select a set of time-frequency resource allocation for transmission of UE-B through inter-terminal cooperation method 1.

In addition, the following methods may be considered when selecting a set of time-frequency resource allocation for UE-B transmission through the inter-terminal cooperation method 1. The present invention is not limited to the method presented below.

Resource selection method in which terminal-to-device cooperation method 1 is used

* Method 1: UE-A independently selects and reserves a set of resources for transmission of UE-A and a set of resources for transmission of UE-B through cooperative method 1 between terminals

** According to the method 1, UE-A may separately select and reserve a resource set X for UE-A transmission and a resource set Y for UE-B transmission. Therefore, periodic reservations can also be applied independently.

* Method 2: UE-A selects and reserves a set of resources for transmission of UE-A by associating a set of resources for transmission of UE-B through method 1 of cooperation between terminals

** According to the method 2, when UE-A selects and reserves the resource set X for UE-A's transmission, the resource set Y for UE-B's transmission may be determined in association with the resource set X. Specifically, an example of the corresponding case is shown in FIG. 11( a ). According to FIG. 11 ( a ), resource X 1101 for transmission of UE-A is selected within the resource selection window 1100 , and resource Y 1102 for transmission of UE-B is for transmission of UE-A. It may be determined from resource X 1101 . For example, a resource reservation period 1103 for resource selection/reservation for transmission of UE-B is set, and resource Y 1102 for transmission of UE-B may be selected/reserved therefrom.

** According to method 2, when UE-A has selected and reserved a resource set Y for UE-B transmission, the resource set X for UE-A transmission may be determined in association with the resource set Y. Specifically, an example of the corresponding case is shown in FIG. 11(b). According to FIG. 11 ( b ), in the resource selection window 1100 , a resource Y 1104 for transmission of UE-B is selected, and a resource X 1105 for transmission of UE-A is for transmission of UE-B. It may be determined from resource Y 1104 . For example, a resource reservation period 1106 for resource selection/reservation for transmission of UE-A is set, and resource X 1105 for transmission of UE-A may be selected/reserved therefrom.

Resource allocation provided by UE-A to UE-B when UE-A cooperation method 1 is used and UE-A provides resource allocation information suitable (preferred) or inappropriate (non-preferred) for transmission of UE-B Whether the information is suitable (preferred) resource allocation information for UE-B transmission or inappropriate (non-preferred) resource allocation information may be additionally indicated. Corresponding information may be signaled as 1-bit information. Such an indication may be made through PC5-RRC when a PC5-RRC connection between terminals is made. In the present invention, the method of exchanging information required for cooperation between terminals is not limited to PC5-RRC. For example, a method in which necessary information is signaled through Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also consist of a combination of one or more of the above methods.

In addition, UE-A cooperation method 1 is used and prior information necessary for UE-A to provide resource allocation information to UE-B needs to be shared between UE-A and UE-B. Specifically, information such as transmission resource pool (TX pool) information used by UE-B, traffic requirements of UE-B, resource configuration information, and CBR measurement result of UE-B needs to be provided to UE-A. . For example, assuming that the transmission resource pool (TX pool) used by UE-B is resource pool A, UE-A must provide the resource selected from resource pool A to UE-B. In general, this is because a transmission resource pool configured in UE-A and a transmission resource pool configured in UE-B may be different from each other. In order for UE-A to provide resource allocation information to UE-B, the UE-B's TX pool is the same as the UE-A's transmission resource pool, or otherwise, it may need to know information about it. If multiple transport pools are configured in UE-B, UE-A may provide a preferred transport pool among multiple transport pools to UE-B. In addition, UE-A may provide UE-B with time-frequency resource allocation information selected for actual resource transmission in the UE-B's transmission resource pool. In this way, in order for UE-A to know the TX pool information of UE-B and to perform inter-terminal cooperation, UE-A indicates to UE-B the transmission resource pool to be used by UE-B, or UE-B The transmission resource pool information to be used by UE-A needs to be indicated to UE-A, or transmission resource pool information needs to be shared between UE-A and UE-B. In addition, it may be assumed that UE-A and UE-B perform inter-terminal cooperation in the corresponding transmission resource pool. When Inter-UE coordination is enabled and UE-A and UE-B are determined, information required for Inter-Terminal Cooperation Method 1 between UE-A and UE-B is limited to the resource pool information presented above. does not Such information exchange may be performed through PC5-RRC when a PC5-RRC connection is established between terminals. In the present invention, the method of exchanging information required for cooperation between terminals is not limited to PC5-RRC. For example, a method in which necessary information is signaled through Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also consist of a combination of one or more of the above methods.

<Fifth embodiment>

In the fifth embodiment, when UE-B receives resource allocation related information from UE-A through inter-terminal cooperation, UE-B's terminal operation will be described. Here, the terminal may be a vehicle terminal and a pedestrian terminal.

First, when the inter-terminal cooperation method 1 is used, the following methods may be considered as the terminal operation of the UE-B. The present invention is not limited to the method presented below. For the condition in which the inter-terminal cooperation method 1 is used, refer to the second embodiment.

Operation of UE-B when Inter-Terminal Cooperation Method 1 is used

* Method 1: UE-B selects a resource for transmission of UE-B using resource allocation information provided from UE-A through inter-terminal cooperation and a result directly sensed by UE-B.

* Method 2: UE-B selects a resource for transmission of UE-B only with resource allocation information provided from UE-A through inter-terminal cooperation.

When the inter-terminal cooperation method 1 is used, only one of the methods presented above may be supported as an operation of the UE-B. Alternatively, when all of the above methods are supported, whether the UE-B uses the method 1 or the method 2 may be determined by the UE implementation. For example, whether to use method 1 or method 2 may be determined according to the power state of UE-B. This is based on the assumption that power consumption can be reduced by performing an additional sensing operation when operating in method 1 and not performing additional sensing when operating in method 2. Therefore, in Mode2 operation, the terminal set to partial sensing or random selection can be limited to operating by method 2. Alternatively, it may be limited to operating in the inter-terminal cooperation method 2 only when the battery level of the terminal is lower than a set threshold value. In the present invention, the method in which the UE-B operation is determined according to the power state of the UE is not limited thereto.

On the other hand, when the inter-terminal cooperation method 2 is used, the following methods may be considered as the terminal operation of the UE-B. The present invention is not limited to the method presented below. For the conditions under which the inter-terminal cooperation method 2 is used, refer to the second embodiment.

Operation of UE-B when Inter-Terminal Cooperation Method 2 is used

* Method 1: UE-B may perform resource reselection from resource allocation information (whether the resource reserved by UE-B is suitable) provided from UE-A through inter-terminal cooperation.

* Method 2: UE-B may perform resource retransmission from resource allocation information (whether or not the resource reserved by UE-B is appropriate) provided from UE-A through cooperation between terminals.

When the inter-terminal cooperation method 2 is used, only one of the methods presented above may be supported as an operation of the UE-B. On the other hand, when all of the above methods are supported, whether the UE-B uses the method 1 or the method 2 may be determined by the UE implementation.

<Sixth embodiment>

In the sixth embodiment, an overall operation in which UE-A and UE-B perform inter-terminal cooperation will be described with reference to FIG. 12A . In the present invention, a terminal providing related information for cooperation between terminals is called UE-A 1201 , and a terminal receiving related information for cooperation between terminals is called UE-B 1202 . For the condition of becoming UE-A and the condition of becoming UE-B when inter-terminal cooperation is performed in the sidelink, refer to the first embodiment. Inter-terminal cooperation information 1203 provided by the UE-A 1201 to the UE-B 1202 may be information related to resource allocation for transmission of the UE-B. For details on such resource allocation related information, refer to the second embodiment. Referring to the second embodiment, the inter-terminal cooperation method 1 and the inter-terminal cooperation method 2 are presented according to the details of resource allocation related information. Also, referring to the second embodiment, conditions for using the inter-terminal cooperation method 1 and the inter-terminal cooperation method 2 are proposed. If the inter-terminal cooperation method 1 is used, refer to the third embodiment for detailed operations for UE-A. In addition, when the inter-terminal cooperation method 2 is used, refer to the fourth embodiment for detailed operations for UE-A. Referring to the fourth embodiment, a terminal operation in which the inter-terminal cooperation method 1 and the inter-terminal cooperation method 2 are combined and operated has also been proposed. Finally, when UE-B receives resource allocation related information from UE-A through inter-terminal cooperation, refer to the fifth embodiment for a method for UE-B to utilize it. The UE may determine a resource to be transmitted by the UE-B or reselect or retransmit a resource to be transmitted by the UE-B by using the inter- UE cooperation information 1203 . In this case, the operation of the UE-B may vary depending on whether the inter-terminal cooperation information 1203 is the inter-terminal cooperation method 1 or the inter-terminal cooperation method 2. Finally, the UE-B may determine the transmission resource of the UE-B from the inter-terminal cooperation information 1203 to perform the PSCCH/PSSCH transmission 1204 . According to FIG. 12A , it is illustrated that the UE-B 1202 performs the PSCCH/PSSCH transmission 1204 to the UE-A 1201 , but the UE-B 1202 is a terminal other than the UE-A 1201 . A case of performing PSCCH/PSSCH transmission 1204 may also be included. In other words, UE-A 1201 may not be the intended receiving terminal for UE-B 1202 .

<Seventh embodiment>

In the seventh embodiment, as another embodiment of the present invention, the overall operation of performing cooperation between terminals will be described with reference to FIG. 12B. For details of the scenario for the TX UE and the Coordinator UE shown in FIG. 12B, refer to FIG. 7 . In particular, in the present embodiment, the scenario of FIG. 7A may be applied. However, it is noted that the scenario of FIG. 7(b) may also be applied. As shown in FIG. 12b, for inter-terminal cooperation in 1210, the TX UE (ie, corresponding to UE-B) provides the Coordinator UE (ie, corresponding to UE-A) to RSAI (Resource Selection Assistant Information, that is, the coordinating of FIG. 7 ) info) can be requested. For a method in which a TX UE and a coordinator UE are determined for cooperation between terminals, refer to Embodiment 1 above. In this case, the request for RSAI may be indicated by SCI (1 ^st SCI or 2 ^nd SCI). The TX UE may instruct the coordinator UE with resource allocation information of the TX UE through SCI (1 ^st SCI) while requesting RSAI from the coordinator UE. Then, the coordinator UE can determine the resource allocation information of the TX UE from the corresponding information. Next, as shown in FIG. 12b, the inter-terminal cooperation method 2 is used in 1211 to determine whether there is a non-preferred resource in the resource allocation information of the TX UE indicated through the SCI (1 ^st SCI). In this case, it may correspond to the method 2 of cooperation between terminals described in the second embodiment. However, in 1211 illustrated in FIG. 12B , information used in method 2 for cooperation between terminals may be limited to the following information capable of solving the half duplex problem. However, in the present invention, only some of the following information may be considered. Also, it is not limited to the following information only. Note that UE-A may be replaced with a coordinator UE and UE-B may be replaced with a TX UE below.

Information for determining that UE-B's resource allocation information is unpreferred in Inter-Terminal Cooperation Method 2

* Information 1: Resource information selected by UE-A for its NR sidelink transmission

** According to information 1 above, when the resource information selected by UE-A for its NR sidelink transmission overlaps in time and frequency with the resource reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH), half Since simultaneous transmission and reception cannot be performed due to duplex, it is possible to determine whether the resource reserved by the UE-B through SCI is suitable through information 1 or not.

** According to information 1, the resource information selected by UE-A for its NR sidelink transmission may mean a set of time-frequency resource allocation selected for (re)transmission of one or more TB (Transport Block). .

** According to information 1, the resource information selected by UE-A for its NR sidelink transmission may include all sets of time-frequency resource allocations selected for (re)transmission of one or more TB (Transport Block). and may include only a subset of them. When only a subset is included, the subset may be limited to only the initial transmission resource. This may be because determining whether the initial transmission resource is inappropriate is more important than the retransmission resource.

* Information 2: Set information of time-frequency resource allocation selected by UE-A for another UE-B

** According to information 2 above, the set information of time-frequency resource allocation selected by UE-A for another UE-B is the resource and time reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH) and In case of overlap in frequency, since reception from different UE-Bs cannot be expected at the same time, information 2 may determine whether the resource reserved by UE-B through SCI is appropriate.

* Information 3: UE-A is scheduled or configured resource information for UL transmission

** According to information 3 above, if resource information scheduled or configured for UL transmission by UE-A overlaps with resources reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH) in time and frequency, half duplex Since transmission and reception cannot be performed at the same time due to , it is possible to determine whether the resource reserved by the UE-B through SCI is appropriate through information 3.

* Information 4: LTE sidelink transmission/reception information of UE-A

** According to information 4 above, when the resource allocation information for LTE sidelink transmission and reception of UE-A overlaps with the resource reserved by UE-B through SCI (1 ^st SCI, in other words, PSCCH) in time and frequency, it is half duplex. Due to the fact that simultaneous transmission and reception cannot be performed or resource collision may be expected, it is possible to determine whether the resource reserved by UE-B through SCI is appropriate through information 4 .

* Information 5: PSFCH transmission/reception information of UE-A

** According to information 5 above, since the PSFCH transmission and reception is determined by the location of the resource allocated for PSSCH transmission, the time and frequency resource location of the PSSCH resource reserved by the UE-B through SCI (1 ^st SCI, in other words, PSCCH) may be determined not to be suitable for PSFCH transmission/reception, and thus, through information 5, it may be determined whether a resource reserved by UE-B through SCI is suitable.

* Information 6: Inter-terminal cooperation information received by UE-A from another UE

** According to information 6 above, when UE-A receives appropriate (preferred) or inappropriate (non-preferred) resource allocation related information from another UE, the resource allocation information determined ^therefrom is In case of overlap in time and frequency with the resource reserved through SCI (in other words, PSCCH), simultaneous transmission and reception due to half duplex or resource collision may be expected. It can be determined whether this is appropriate.

Next, according to FIG. 12B , if the coordinator UE is set to use the inter-terminal cooperation method 2 according to step 1212 , the coordinator UE may transmit an RSAI to the TX UE in step 1214 . At this time, the RSAI may indicate only whether resource collision is expected with 1 bit because it is determined that the resource allocation information of UE-B is unpreferred.

On the other hand, as shown in FIG. 12B , if the coordinator UE is set to use the inter-terminal cooperation method 1 in 1212 , it moves to step 1213 and uses the sensing result of the coordinator UE to resource allocation information of the TX UE. Select (preferred resource). The setting of the inter-terminal cooperation method 1 or the inter-terminal cooperation method 2 in 1212 refers to the second embodiment. In addition, for details of step 1213, refer to the method 1 of cooperation between terminals described through the second and fourth embodiments. For example, step 1213 may be described as follows. Note that UE-A may be replaced with a coordinator UE and UE-B may be replaced with a TX UE below.

How to select a preferred resource of UE-B in Inter-Terminal Cooperation Method 1

* Result for UE-A to perform sensing

** In the above method, sensing by UE-A may mean SCI (1 ^st SCI, in other words, PSCCH) decoding and SL RSRP (Sidelink Reference Signal Received Power) measurement. Both SCI decoding and SL RSRP measurement may be included, or only one of them may be included. UE-A may select a resource suitable for transmission of UE-B through sensing, and refer to Embodiment 4 for details. Specifically, referring to step 5) in Example 4, a resource unfavorable to the resource allocation information of the TX UE identified in step 1211 may be excluded from the candidate resource. In other words, it is noted that the inter-terminal cooperation method 1 and the inter-terminal cooperation method 2 may be used and applied at the same time. If, when the inter-terminal cooperation method 1 is used in step 1213 but information through the inter-terminal cooperation method 2 in step 1211 is not available, the corresponding information may not be used in step 1213 .

Next, as shown in FIG. 12B, moving to step 1214 to the next step of 1213, the coordinator UE may transmit the RSAI to the TX UE. In this case, RSAI may indicate time and frequency location information of a resource selected as UE-B's preferred resource set information through the UE-B cooperation method 1 determined in step 1213 .

12B, when the coordinator UE transmits the RSAI to the TX UE in step 1214, when the inter-terminal cooperation method 1 or the inter-terminal cooperation method 2 is used, both may be indicated through ^2nd SCI. However, the present invention is not limited to the corresponding instruction method.

12B, the TX UE that finally received the RSAI from the coordinator UE in 1215 may (re)select a transmission resource using the corresponding RSAI information. For details, refer to Example 5 above.

In order to carry out the above embodiments of the present invention, the transmitting unit, the receiving unit, and the processing unit of the terminal and the base station are shown in FIGS. 13 and 14, respectively. In the above embodiments, a method for the terminal to perform multi-antenna transmission and reception in the sidelink is shown, and to perform this, the receiving unit, the processing unit, and the transmitting unit of the base station and the terminal may each operate according to the embodiment.

13 is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.

As shown in FIG. 13 , the terminal of the present invention may include a terminal receiving unit 1300 , a terminal transmitting unit 1304 , and a terminal processing unit 1302 . The terminal receiving unit 1300 and the terminal transmitting unit 1304 may be collectively referred to as a transceiver in the embodiment of the present invention. The transceiver may transmit/receive a signal to/from the base station. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel and output it to the terminal processing unit 1302 , and transmit the signal output from the terminal processing unit 1302 through a wireless channel. The terminal processing unit 1302 may control a series of processes so that the terminal can operate according to the above-described embodiment of the present invention.

14 is a block diagram illustrating an internal structure of a base station according to an embodiment of the present disclosure.

As shown in FIG. 14 , the base station of the present invention may include a base station receiving unit 1401 , a base station transmitting unit 1405 , and a base station processing unit 1403 . The base station receiving unit 1401 and the base station transmitting unit 1405 may be collectively referred to as a transceiver in the embodiment of the present invention. The transceiver may transmit/receive a signal to/from the terminal. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel and output it to the base station processing unit 1403 , and transmit the signal output from the base station processing unit 1403 through the wireless channel. The base station processing unit 1403 may control a series of processes so that the base station can operate according to the above-described embodiment of the present invention.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are only presented as specific examples to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. That is, it will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications can be implemented based on the technical spirit of the present invention. In addition, each of the above embodiments may be operated in combination with each other as needed. For example, in all embodiments of the present invention, parts may be combined with each other to operate a base station and a terminal.

Claims (1)

A control signal processing method in a wireless communication system, comprising:
Receiving a first control signal transmitted from the base station;
processing the received first control signal; and
and transmitting a second control signal generated based on the processing to the base station.

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