KR20230042980A - A method and an apparatus for sidelink inter-ue coordination in wireless communication system - Google Patents

Abstract

The present invention provides a cooperation information providing method of a terminal which comprises the following steps of: receiving a message requesting resource selection assistance information (RSAI) to be used for communication of a second terminal from the second terminal; determining whether to provide feedback information for an RSAI request based on the message; determining the RSAI based on a determination result; and transmitting feedback information including the determined RSAI to the second terminal.

Description

Method and apparatus for cooperation between sidelink terminals in a wireless communication system

The present disclosure relates to a wireless mobile communication system, and in particular, inter-UE cooperation (Inter-UE) in a process in which a terminal supporting vehicle-to-everything (V2X) transmits and receives information with another terminal using a side link. It relates to a method and apparatus for performing coordination.

An improved 5G communication system or pre-5G communication system is being developed to meet the explosively increasing demand for wireless data traffic due to the commercialization of 4G communication systems and the increase in multimedia services. For this reason, the 5G communication system or pre-5G communication system is being called a system after a 4G network (Beyond 4G Network) communication system or an LTE system (Post LTE).

In order to increase the data transmission rate, the 5G communication system is being considered for implementation in a mmWave band (eg, a 60 gigabyte (60 GHz) band). In order to mitigate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used in 5G communication systems. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed.

In addition, in order to improve the network performance of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), and an ultra-dense network network), Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and receive interference cancellation cancellation) is being developed. In addition, in the 5G system, advanced coding modulation (Advanced Coding Modulation: ACM) methods FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), advanced access technologies FBMC (Filter Bank Multi Carrier), NOMA (non orthogonal multiple access), SCMA (sparse code multiple access), etc. are being developed.

On the other hand, the Internet is evolving from a human-centered network in which humans create and consume information to an Internet of Things (IoT) network in which information is exchanged and processed between distributed components such as things. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with a cloud server, etc., is also emerging. In order to implement IoT, technical elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, sensor networks for connection between objects and machine to machine , M2M), and MTC (Machine Type Communication) technologies are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new values in human life by collecting and analyzing data generated from connected objects 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 appliances, 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 machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antenna, and 5G communication technologies There is. The application of the cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of convergence of 5G technology and IoT technology.

As various services can be provided according to the above and the development of wireless communication systems, there is a demand for a method for providing a method of cooperation between terminals, particularly in sidelink.

The present disclosure relates to a wireless communication system, in which a terminal supporting V2X exchanges information with another terminal using a side link, a method for sharing information that can be helpful between terminals through cooperation between terminals, and It's about the device. Specifically, it relates to a method for exchanging information for inter-UE coordination and a terminal operation therefor.

The present disclosure provides a method for providing cooperation information of a first terminal, comprising: receiving a message requesting resource selection assistance information (RSAI) to be used for communication of the second terminal from a second terminal; Determining whether to provide feedback information for the RSAI request based on the message; determining the RSAI based on the determination result; and transmitting feedback information including the determined RSAI to the second terminal.

The disclosed embodiment provides a device and method capable of effectively providing services in a mobile communication system.

1 is a diagram illustrating a communication system according to an embodiment of the present disclosure.
2 is a diagram illustrating a V2X communication method through a sidelink according to an embodiment of the present disclosure.
3 is a diagram illustrating a resource pool defined as a set (set) of resources on time and frequency used for transmission and reception of a sidelink according to an embodiment of the present disclosure.
4 is a diagram illustrating a method of allocating transmission resources in a sidelink by a base station according to an embodiment of the present disclosure.
5 is a diagram illustrating a method of directly allocating transmission resources of a sidelink through sensing in a sidelink according to an embodiment of the present disclosure.
6 is a diagram illustrating a mapping structure of sidelink physical channels mapped to one slot according to an embodiment of the present disclosure.
7 is a diagram illustrating a method of performing cooperation between terminals in a sidelink according to an embodiment of the present disclosure.
8 is a diagram illustrating two methods of performing cooperation between terminals according to an embodiment of the present disclosure.
9 is a diagram for explaining a first method of performing cooperation between terminals based on an explicit request according to an embodiment of the present disclosure.
10 is a diagram for explaining a first method of performing cooperation between terminals based on a specific condition according to an embodiment of the present disclosure.
11 is a diagram for explaining a second method of performing cooperation between terminals according to an embodiment of the present disclosure.
12 is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.
13 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 it by omitting unnecessary description.

For the same reason, in the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. In each figure, the same reference number is assigned to the same or corresponding component.

Advantages and features of the present disclosure, and methods of achieving them, will become clear 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 and may be implemented in various different forms, only the present embodiments make the present disclosure complete, and those of ordinary skill in the art to which the present disclosure belongs 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 numbers designate like elements throughout the specification.

At this time, it will be understood that each block of the process flow chart diagrams and combinations of the flow chart diagrams can 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, so that the instructions executed by the processor of the computer or other programmable data processing equipment are described in the flowchart block(s). It creates means to perform functions. These computer program instructions may also be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular way, such that the computer usable or computer readable memory The instructions stored in are also capable of producing an article of manufacture containing instruction means that perform the functions described in the flowchart block(s). The computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to generate computer or other programmable data processing equipment. Instructions for performing processing equipment may also provide steps for carrying out 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 possible for the functions mentioned in the blocks to occur out of order. For example, two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in reverse order depending on their function.

At this time, the term '~unit' used in this embodiment means software or a hardware component such as FPGA or ASIC, and '~unit' performs certain roles. However, '~ part' is not limited to software or hardware. '~bu' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Therefore, as an example, '~unit' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Functions provided within components and '~units' may be combined into smaller numbers 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 a secure multimedia card. Also, in the embodiment, '~ unit' may include one or more processors.

In the specific description of the embodiments of the present disclosure, the radio access network New RAN (NR) on the 5G mobile communication standard disclosed by the 3rd generation partnership project long term evolution (3GPP), a mobile communication standardization organization, and the packet core (a core network) 5G System, or 5G Core Network, or NG Core: next generation core) as the main target, but the main point of the present disclosure is to other communication systems having a similar technical background to the extent that it does not greatly depart from the scope of the present disclosure. It can be applied with slight modifications, which will be possible with the judgment of those 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 of analyzing and providing data collected from the 5G network, can 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 standards (5G, NR, LTE, or similar system standards) 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.

Also used in the following description are terms for identifying access nodes, terms for network entities (network entities), terms for messages, terms for interfaces between network entities, and various types of identification information. Terms and the like referring to are illustrated for convenience of description. Therefore, it is not limited to the terms used in this disclosure, and other terms that refer to objects having equivalent technical meanings may be used.

Efforts are being made to develop an improved 5G communication system (NR, New Radio) in order to meet the growing demand for wireless data traffic after the commercialization of the 4G communication system. In order to achieve a high data rate, the 5G communication system is designed to enable resources in a mmWave band (eg, a 28 GHz frequency band). In order to mitigate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used in 5G communication systems. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, unlike LTE, the 5G communication system volunteers various subcarrier spacings such as 30 kHz, 60 kHz, and 120 kHz, including 15 kHz, and uses Polar Coding for the physical control channel. The data channel (Physical Data Channel) uses LDPC (Low Density Parity Check). In addition, not only DFT-S-OFDM but also CP-OFDM are used as waveforms for uplink transmission. In LTE, HARQ (Hybrid ARQ) retransmission in units of TB (Transport Block) is resourced, whereas 5G may additionally volunteer HARQ retransmission based on Code Block Group (CBG) in which several Code Blocks (CBs) are bundled.

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

On the other hand, the Internet is evolving from a human-centered connection network in which humans create and consume information to an Internet of Things (IoT) network in which information is exchanged and processed between distributed components such as things. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, etc., is also emerging. In order to implement IoT, technical elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, sensor networks for connection between objects and machine to machine , M2M), and MTC (Machine Type Communication) technologies are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new values in human life by collecting and analyzing data generated from connected objects 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 appliances, 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 machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antenna, which are 5G communication technologies. . The application of the cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of convergence of 5G technology and IoT technology. In this way, a plurality of services can be provided to users in a communication system, and in order to provide such a plurality of services to users, a method capable of providing each service within the same time period according to characteristics and a device using the same are required. . Various services provided by 5G communication systems are being studied, and one of them is a service that satisfies low latency and high reliability requirements. In particular, in the case of vehicle communication, unicast communication between terminals and terminals, groupcast (or multicast) communication, and broadcast communication are supported in the NR V2X system. In addition, NR V2X, unlike LTE V2X, which aims to transmit and receive basic safety information required for vehicle road driving, is group driving (platooning), advanced driving (Advanced Driving), extended sensor (Extended Sensor), remote driving (Remote Driving) and We aim to provide more advanced services together.

In particular, inter-UE coordination may be considered in sidelink. Cooperation between terminals may mean providing a more improved sidelink service by sharing helpful information between terminals. In the present disclosure, information shared through cooperation between terminals is not limited to specific information. For example, information shared through cooperation between terminals may include resource selection assistance information (hereinafter referred to as RSAI). Of course, it is not limited to the above examples.

In the present disclosure, various methods may be considered when a UE provides RSAI as cooperation information between UEs. In addition, the present disclosure may provide a cooperation procedure between terminals according to a method of providing RSAI. The cooperation procedure between UEs includes RSAI information setting method, RSAI triggering method, RSAI feedback or RSAI validity confirmation when RSAI is received, RSAI signaling method when UE feedbacks RSAI, and RSAI receiving RSAI. How to use it may be included. Of course, it is not limited to the above examples.

Also, in the present disclosure, a method of signaling RSAI when RSAI feedback is provided in detail. For example, when sharing cooperation information between UEs, 2nd Sidelink Control Information (SCI) transmitted through a Physical Sidelink Shared Channel (PSSCH) channel may be considered. At this time, detailed information that can be included in the 2nd SCI and methods for using the detailed information that can be included in the 2nd SCI are presented. Through the method proposed in the present disclosure, cooperation information between terminals can be transmitted through 2nd SCI regardless of whether or not the terminal has data to be transmitted, and thus latency of providing cooperation information between terminals can be reduced.

An embodiment of the present disclosure is proposed to support the above-described scenario, and in particular, in the present disclosure, a method for transmitting control information for cooperation between terminals through 2 ^nd SCI, and a case in which control information is transmitted together with data An object of the present invention is to provide a procedure for performing cooperation between terminals through a corresponding indication considering a case where it is not the case.

In the present invention, it is to propose an inter-UE coordination method in sidelink communication and a procedure for sharing information that can be helpful between terminals through this. The proposed method can prevent an increase in delay time occurring in sharing the corresponding information.

1 is a diagram showing a system according to an embodiment of the present disclosure.

Referring to FIG. 1, (a) of FIG. 1 shows an example of a case in which all V2X terminals (UE-1 and UE-2) are located within the coverage of a base station (In-Coverage, IC). All V2X terminals may receive data and control information from the base station through downlink (DL) or transmit data and control information to the base station through uplink (UL). At this time, data and control information may be data and control information for V2X communication. Data and control information may be data and control information for general cellular communication. In addition, V2X terminals can transmit / receive data and control information for V2X communication through sidelink (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 a base station and UE-2 is located outside the coverage of the base station among V2X terminals. That is, (b) of FIG. 1 may show an example of 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 to the base station through uplink. 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 with the V2X terminal (UE-1) through a side link.

Referring to FIG. 1, (c) of FIG. 1 shows an example of a case where all V2X terminals are located outside the base station's coverage (out-of coverage, OOC). Therefore, the V2X terminals (UE-1 and UE-2) 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. V2X terminals (UE-1, UE-2) can transmit / receive data and control information for V2X communication through sidelinks.

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 and UE-2) located in different cells. Specifically, in (d) of FIG. 1, V2X terminals (UE-1, UE-2) are connected to different base stations (RRC connection state) or camping (RRC connection disconnection state, ie 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.

A V2X terminal (UE-1) may receive a system information block (SIB) from a base station to which it has accessed (or is camping), and a V2X terminal (UE-2) to which it has accessed (or is camping) camping) can receive SIBs from other base stations. At this time, as the SIB, an existing SIB may be used or a SIB defined separately for V2X may be used. In addition, SIB information received by the V2X terminal (UE-1) and SIB information 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, it is necessary to additionally interpret SIB information transmitted from different cells by unifying information or signaling information about this. may be

1 shows a V2X system composed of V2X terminals (UE-1 and UE-2) for convenience of description, but is not limited thereto and communication may be made between more V2X terminals. In addition, an interface (uplink and downlink) between a base station and V2X terminals may be named a Uu interface, and a sidelink between V2X terminals may be named a PC5 interface. Therefore, in the present disclosure, they may be used interchangeably. Meanwhile, in the present disclosure, a terminal is a vehicle supporting vehicle-to-vehicular (V2V) communication, a vehicle supporting communication between a vehicle and a pedestrian (vehicular-to-pedestrian, V2P), or a handset of a pedestrian (eg, , smartphone), a vehicle supporting communication between a vehicle and a network (vehicular-to-network, V2N), or a vehicle supporting communication between a vehicle and a transportation infrastructure (vehicular-to-infrastructure, V2I). there is. In addition, in the present disclosure, a 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 a base station function and a part of a 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. Therefore, in the present disclosure, a base station may be referred to as an RSU.

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

Referring to (a) of FIG. 2, UE-1 (201, eg TX terminal) and UE-2 (202, eg RX terminal) may perform one-to-one communication, which is It can be called 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 groupcast or multicast. In (b) of FIG. 2, UE-1 211, UE-2 212, and UE-3 213 form a group (Group A) to perform groupcast communication. And, the UE-4 (214), UE-5 (215), UE-6 (216), and UE-7 (217) form another group (Group B) to communicate through groupcast can be performed. Each terminal performs groupcast communication only within the group to which it belongs, and communication between different groups may be performed through unicast, groupcast, or broadcast communication. In (b) of FIG. 2, it is shown that two groups (Group A and Group B) are formed, but it is not limited thereto.

Meanwhile, although not shown in FIG. 2, V2X terminals may perform broadcast communication. Broadcast communication refers to a case in which all V2X terminals receive data and control information transmitted by a V2X transmission terminal through a side link. For example, in (b) of FIG. 2, if it is assumed that UE-1 (211) is a transmitting terminal for broadcasting, all terminals (UE-2 (212), UE-3 (213), UE -4 (214), UE-5 (215), UE-6 (216), and UE-7 (217)) can receive data and control information transmitted by UE-1 (211).

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

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.

According to an embodiment of the present disclosure, a resource granularity of a time axis in a resource pool may be a slot. Also, a 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 resource pools are allocated non-contiguously in time is described, but resource pools may be allocated in succession in time. In addition, in the present disclosure, an example of a case in which resource pools are contiguously allocated in frequency is described, but a method in which resource pools are discontiguously allocated in frequency is not excluded.

Referring to FIG. 3, a case 301 in which resource pools are allocated non-contiguously in time is shown. Referring to FIG. 3, a case in which the granularity of resource allocation in time consists of slots is illustrated. First, a sidelink slot may be defined within a slot used for uplink. Specifically, the length of a symbol used as a sidelink within one slot may be set as sidelink BWP (Bandwidth Part) information. Therefore, among slots used for uplink, slots for which the length of symbols set for sidelink is not guaranteed cannot be sidelink slots. Also, slots belonging to the resource pool may exclude slots in which a Sidelink Synchronization Signal Block (S-SSB) is transmitted.

)로 도시 되었다. 도 3의 301에서 색칠된 부분은 자원 풀에 속한 사이드링크 슬롯들을 나타낸다. 자원 풀에 속한 사이드링크 슬롯들은 비트맵을 통해 자원 풀 정보로 (pre-)configuration될 수 있다. 도 3의 302를 참조하면, 시간상에서 자원 풀에 속한 사이드링크 슬롯의 셋(집합)이 (

)로 도시 되었다. Referring to 301 of FIG. 3, a set (set) of slots that can be used as sidelinks in time, except for slots in which the length of symbols set as sidelinks is not guaranteed (

) was shown. Colored parts in 301 of FIG. 3 represent sidelink slots belonging to a resource pool. Sidelink slots belonging to a resource pool may be (pre-)configurated with resource pool information through a bitmap. Referring to 302 of FIG. 3, the set (set) of sidelink slots belonging to the resource pool in time (

) was shown.

In the present disclosure, the meaning of (pre-)configuration may mean configuration information pre-configurated and stored in a terminal, or may mean a case in which a terminal is configured in a cell-common manner from a base station. Here, cell-common may mean that terminals in the cell receive configuration of the same information from the base station.

At this time, a method in which the UE receives 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 where 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.

At this time, a method of obtaining UE-specific information by receiving an RRC message from the base station may be considered. In addition, (pre-)configuration can be considered a method in which resource pool information is set and a method in which resource pool information is not set. In the case of (pre-)configuration with resource pool information, all terminals operating in the resource pool will be operated with common configuration information, except for the case where the terminal is configured in a UE-specific way after the 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 set independently of the resource pool configuration information.

For example, one or more modes are (pre-)configurated in a resource pool (eg, A, B, and C), and (pre-)configurated information independently of the resource pool configuration information is added to the resource pool (pre-)configuration. ) Can indicate which of the configured modes to use (for example, A or B or C).

Referring to 303 in FIG. 3, a case in which resource pools are continuously allocated on a frequency is illustrated. In the frequency axis, resource allocation may be configured with sidelink Bandwidth Part (BWP) 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 5 consecutive PRBs, and a subchannel size (sizeSubchannel) may be the size of 5 consecutive PRBs. However, the content shown in the drawing is only an example of the present invention, and the size of a subchannel may be set differently, and one subchannel is generally composed of continuous PRBs, but it is not necessarily composed of continuous PRBs.

According to an embodiment of the present disclosure, a subchannel may be a basic unit of resource allocation for PSSCH. In 303, startRB-Subchannel may indicate a start position of a subchannel on a frequency in a resource pool. When resource allocation is performed in units of subchannels on the frequency axis, the RB (Resource Block) index at which the subchannel starts (startRB-Subchannel), information on how many PRBs the subchannel consists of (sizeSubchannel), and the total number of subchannels Resources on a frequency may be allocated through setting information such as (numSubchannel). At this time, information on startRB-Subchannel, sizeSubchannel, and numSubchannel may be (pre-)configurated as resource pool information on a frequency.

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

A method of allocating transmission resources in a sidelink by a base station will be referred to as Mode 1 below. Mode 1 may be scheduled resource allocation. Mode 1 may indicate a method in which a base station allocates resources used for sidelink transmission to RRC-connected terminals in a dedicated scheduling scheme. 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). Camp on may mean, 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. .

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). Unlike this, 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 .

According to an embodiment of the present disclosure, 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 and reception, parameter setting information for sensing operation, information for setting sidelink synchronization, or carrier information for sidelink transmission and reception operating in different frequencies. etc. may be included.

When data traffic for V2X is generated in the transmission terminal 401, the transmission terminal 401 may be connected to the base station 403 and RRC (420). 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 is generated by the transmitting terminal 401 . In addition, 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 completed, the transmitting terminal may perform transmission to the receiving terminal through the sidelink. Unlike 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 can transmit to the receiving terminal through the sidelink.

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

Next, the base station 403 may allocate V2X transmission resources to the transmission terminal 401 . At this time, the base station may allocate transmission resources in a dynamic grant or configured grant scheme.

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

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. At this time, the base station may allocate resources for one TB through DCI. 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 initial transmission and retransmission for one TB can be determined by DCI, and resources for the next TB can be repeated at SPS interval intervals. . DCI for the configured grant method may be CRC scrambled with SL-SPS-V-RNTI to indicate that it is the 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/deactivate resources set with configured grant through DCI.

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

Specifically, downlink control information (DCI) used by the base station 403 for sidelink communication with the transmitting terminal 401 may include DCI format 3_0 or DCI format 3_1. 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 RRC configuration 415 for the sidelink. Unlike this, in the case of unicast or group cast transmission, the transmitting terminal 401 may perform a one-to-one RRC connection with another terminal. Here, the RRC connection between terminals may be referred to as PC5-RRC 415, distinguished from Uu-RRC. In the case of a group cast, the PC5-RRC 415 may be individually connected between terminals in a group. Referring to FIG. 4, although the connection of the PC5-RRC 415 is shown as an operation after the transmission of the SL-SIB (410), it may be performed at any time before the transmission of the SL-SIB (410) or before the transmission of the SCI.

Next, the transmitting terminal 401 may transmit SCI (1st stage) to the receiving terminal 402 through a physical sidelink control channel (PSCCH) (460). In addition, the transmitting terminal 401 may transmit SCI (2nd stage) 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, SCI (1st stage), SCI (2nd stage), and PSSCH may be transmitted together in the same slot.

5 is a sequence diagram illustrating a method for a UE to directly allocate transmission resources of a sidelink through sensing in a sidelink according to an embodiment of the present disclosure.

Hereinafter, a method in which a UE directly allocates transmission resources of a sidelink through sensing in the sidelink will be referred to as Mode 2. In the case of Mode 2, it may be referred to as UE autonomous resource selection. In Mode 2, the base station 503 provides a sidelink transmission/reception resource pool for V2X as system information, and the transmission terminal 501 can select transmission resources according to a set rule. Unlike Mode 1, in which the base station directly participates in resource allocation, in FIG. 5, 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.

Referring to FIG. 5 , a transmitting terminal 501 may camp on a base station (cell) 503 (505). Camp on may mean, 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. . Also, referring to FIG. 5, unlike FIG. 4 described above, in the case of Mode 2, 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) 503 ) can camp on (507). Unlike this, 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). In contrast, 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 may include sidelink resource pool information for sidelink transmission and reception, parameter setting information for sensing operation, information for setting sidelink synchronization, or carrier information for sidelink transmission and reception operating in different frequencies. can

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. condition) can work. Also, even in the RRC connected state 520, the base station 503 may allow the transmitting terminal 501 to autonomously select transmission resources without directly participating in resource allocation. Here, the RRC connection between the terminal 501 and the base station 503 may be referred to as Uu-RRC 520. When data traffic for V2X is generated in the transmitting terminal 501, the transmitting terminal 501 receives a resource pool through the system information received from the base station 503, and the transmitting terminal 501 senses within the configured resource pool. It is possible to directly select resources 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 RRC configuration 515 for the sidelink. Unlike this, in the case of unicast or group cast transmission, the transmitting terminal 501 may perform a one-to-one RRC connection with another terminal. Here, the RRC connection between terminals may be referred to as PC5-RRC 515, distinguished from Uu-RRC. In the case of a group cast, the PC5-RRC 515 may be individually connected between terminals in a group. Referring to FIG. 5, although the connection of the PC5-RRC 515 is shown as an operation after the transmission of the SL-SIB (510), it may be performed at any time before the transmission of the SL-SIB (510) or before the transmission of the SCI.

Next, the transmitting terminal 501 may transmit SCI (1st stage) to the receiving terminal 502 through the PSCCH (550). In addition, the transmitting terminal 401 may transmit SCI (2nd stage) 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, SCI (1st stage), SCI (2nd stage), and PSSCH may be transmitted together in the same slot.

Specifically, SCI (Downlink Control Information) used by the transmitting terminals 401 and 501 to the receiving terminals 402 and 502 for sidelink communication may have SCI format 1-A as SCI (1st stage). Also, there may be SCI format 2-A or SCI format 2-B as SCI (2nd stage). In SCI (2nd stage), SCI format 2-A may include information for PSSCH decoding when HARQ feedback is not used or when HARQ feedback is used and includes both ACK or NACK information. In contrast, SCI format 2-B may be used by including 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 used only for groupcast transmission.

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

Specifically, an example in which physical channels of a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), and a Physical Sidelink Feedback Channel (PSFCH) can be mapped is illustrated in FIG. 6 . In the case of PSFCH, when sidelink HARQ feedback is activated in a higher layer, time-wise resources of PSFCH may be (pre-)configurated with resource pool information. For example, a time resource in which the PSFCH is transmitted may be (pre-)configurated with one value among 0, 1, 2, and 4 slots. Here, '0' means that the PSFCH resource is not used. And, 1, 2, and 4 may mean that PSFCH resources are transmitted in every 1, 2, and 4 slots, respectively.

FIG. 6(a) shows a structure of a slot in which PSFCH resources are not used, and FIG. 6(b) shows a structure of a slot in which PSFCH resources are set and can be transmitted. PSCCH/PSSCH/PSFCH may be allocated to one or more subchannels in frequency. For details on subchannel allocation, refer to the description of FIG. 3 . Next, referring to FIG. 6 to explain the mapping of PSCCH/PSSCH/PSFCH in time, one or more symbols before the transmitting terminal transmits the PSCCH/PSSCH/PSFCH in the corresponding slot are a region 601 for automatic gain control (AGC). ) can be used.

According to FIG. 6, control information related to resource allocation in the first symbols of a slot is transmitted through PSCCH 602 as 1st sidelink control information (SCI), and other control information is transmitted as 2nd SCI 604 in PSSCH area 603 can be sent to Data scheduled by the control information may be transmitted through the PSSCH 603. In this case, the position in time at which the 2nd stage SCI is transmitted may be mapped from a symbol in which the first PSSCH DMRS (606 or 607) is transmitted. A position in time at which the PSSCH DMRS is transmitted may vary according to a PSSCH region allocated to a slot as shown in FIGS. 6A and 6B.

605 of FIG. 6 shows an example in which symbols for transmission of signals other than the PSSCH are located in the last area of the slot. Specifically, in FIG. 6(a), there is one symbol corresponding to 605, and in this case, the symbol corresponding to 605 is used as a gap symbol. In contrast, FIG. 6(b) shows a case where a plurality of symbols corresponding to 605 are secured, and the corresponding symbol region can be used as a gap symbol, a PSFCH symbol, and a downlink (DL) / uplink (UL) symbol.

는 하기 수학식 1와 같이 계산될 수 있다. 이하 수학식 1에서 심볼 인덱스

은 AGC를 위해 사용되는 슬롯 내 첫 번째 심볼을 제외하고 PSCCH/PSSCH를 전송하기 위해 사용되는 심볼들을 기준으로 정의될 수 있다.First, in (a-1) and (b-1) of FIG. 6, an example of a case in which data is transmitted together in the PSSCH region when the 2 ^nd SCI is transmitted through the PSSCH is shown. In this way, when data is transmitted in the PSSCH region when the ^2nd SCI is transmitted through the PSSCH, the number of bits or symbols in which the ^2nd SCI is coded using channel coding

Can be calculated as in Equation 1 below. Symbol index in Equation 1 below

may be defined based on symbols used to transmit PSCCH/PSSCH except for the first symbol in a slot used for AGC.

[Equation 1]

In Equation 1,

는 2^nd SCI에 포함된 정보의 비트수를 나타낸다. 사용된 2^nd SCI 포맷에 따라 포함된 정보의 비트수가 달라질 수 있다.*

represents the number of bits of information included in the ^2nd SCI. The number of bits of included information may vary depending on the used ^2nd SCI format.

는 2^nd SCI에 사용되는 CRC 비트수를 사용하며 24비트가 사용될 수 있다.*

uses the number of CRC bits used for ^2nd SCI, and 24 bits can be used.

는 2^nd SCI의 코딩된 비트 수를 조절하기 위한 파라미터로서 1^st SCI에 포함된 비트 필드를 사용하여 결정될 수 있다.*

may be determined using a bit field included in the ^1st SCI as a parameter for adjusting the number of coded bits of the ^2nd SCI.

는 2^nd SCI에 전송에 사용되는 변조도를 나타낸다. 해당 값은 QPSK로 고정될 수 있다.*

represents a modulation degree used for transmission in ^2nd SCI. The corresponding value may be fixed as QPSK.

* R represents the coding rate used for transmission in ^2nd SCI. The corresponding value may be determined using a bit field included in ^1st SCI, and the coding rate may be the same as the coding rate used for data transmission.

는 심볼 인덱스 l 에서 2^nd SCI에 전송에 사용되는 RE (Resource Element)의 수로

로 정의될 수 있다. 여기서

는 심볼 인덱스 l 에서 PSSCH 전송으로 스케줄링 된 bandwidth의 RE수를 나타내며,

는 심볼 인덱스 l에서 PSCCH와 PSCCH DMRS의 전송에 사용되는 subcarrier의 수, 즉 RE수를 나타낸다. *

is the number of REs (Resource Elements) used for transmission to the ^2nd SCI at symbol index l.

can be defined as here

Represents the number of REs of bandwidth scheduled for PSSCH transmission at symbol index l,

represents the number of subcarriers used for transmission of PSCCH and PSCCH DMRS at symbol index l, that is, the number of REs.

는 PSSCH가 전송되는 심볼 수를 나타내며

로 정의될 수 있다. 여기서

=sl-lengthSymbols-2로 정의 될 수 있으며 sl-lengthSymbols는 사이드링크로 사용되는 심볼 수로 {7,8,9,10,11,12,13,14}의 값 중 하나가 상위 레이어로 설정될 수 있다.

의 값을 결정할 때 sl-lengthSymbols에서 2를 빼는 이유는 슬롯의 첫 AGC 심볼과 마지막 gap 심볼을 고려한 것이다.

는 PSFCH가 전송되는 슬롯에서는

으로 PSFCH가 전송되지 않는 슬롯에서는

으로 결정될 수 있다. *

Represents the number of symbols in which the PSSCH is transmitted.

can be defined as here

= sl-lengthSymbols -2, and sl-lengthSymbols is the number of symbols used as sidelinks. One of the values of {7,8,9,10,11,12,13,14} can be set as the upper layer. there is.

The reason for subtracting 2 from sl-lengthSymbols when determining the value of is to consider the first AGC symbol and the last gap symbol of the slot.

In the slot in which the PSFCH is transmitted,

In slots where PSFCH is not transmitted,

can be determined by

는 2^nd SCI가 매핑되는 양을 결정하는 파라미터로 사용되는 값이며 상위 레이어로 설정된 값이 될 수 있다. 예를 들어, {0.5, 0.65, 0.8, 1}의 값 중에서 선택될 수 있다. *

is a value used as a parameter for determining the amount to which ^2nd SCI is mapped, and may be a value set in an upper layer. For example, it may be selected from values of {0.5, 0.65, 0.8, 1}.

는 2^nd SCI가 매핑될 때, 2^nd SCI가 코딩되어 생성된 (변조) 심볼 중 마지막 심볼이 매핑되는 (OFDM 또는 SC-FDMA) 심볼의 RB에 남는 RE(즉 2^nd SCI가 매핑되지 않는 RE)가 있다면, 해당 RB의 남은 모든 RE에 2^nd SCI가 매핑되도록 정해지는 변수이다.*

When the ^2nd SCI is mapped, the RE remaining in the RB of the (OFDM or SC-FDMA) symbol to which the last symbol among the (modulated) symbols generated by coding the ^2nd SCI is mapped (that is, the RE to which the ^2nd SCI is not mapped) ), it is a variable determined so that the 2 ^nd SCI is mapped to all remaining REs of the corresponding RB.

Unlike (a-1) and (b-1), an example of a case in which data is not transmitted together in the PSSCH region when the 2 ^nd SCI is transmitted through the PSSCH is (a-2) and (b-2), respectively. city through When data is not transmitted in the PSSCH region and the 2 ^nd SCI is mapped to the PSSCH region according to Equation 1, as shown in 608 of (a-2) and 609 of (b-2), 2 ^nd SCI If is mapped to only a part of the frequency domain of the PSSCH in the last symbol to be transmitted, power imbalance may occur between the corresponding symbol and the previous symbol (s) to which the 2 ^nd SCI is mapped. In other words, in the previous symbol(s) to which the ^2nd SCI is mapped, all of the ^2nd SCI is transmitted in the frequency domain of the PSSCH, but in the last symbol in which the ^2nd SCI is transmitted, the ^2nd SCI is mapped only to a part of the frequency domain of the PSSCH. The power of the inter-transmission signal may not be constant. When such a power imbalance occurs, difficulties may occur in transmitting and receiving signals. Therefore, in order to solve this problem, when the ^2nd SCI is transmitted through the PSSCH, a ^2nd SCI mapping method can be operated differently when data is transmitted together in the PSSCH region and when it is not.

FIG. 6C is a diagram for explaining the operation of a terminal that operates a ^2nd SCI mapping method differently depending on whether control information is transmitted together with data or not when transmitting control information through a ^2nd SCI according to an embodiment of the present disclosure; am.

의 값을 설정하고

의 값을 1로 설정하고

의 값을 0으로 설정함으로써 2^nd SCI를 PSSCH의 모든 영역에 매핑 되도록 전송할 수 있다. 또 다른 일 예로, 아래 수학식 2와 같이 표현될 수 있다. According to FIG. 6C, when the terminal transmits control information through the ^2nd SCI in step 610, if it is transmitted together with data, it can move to step 611 and use the ^2nd SCI mapping method 1. Specifically, in the ^2nd SCI mapping method 1, according to Equation 1, the number of bits or symbols in which the ^2nd SCI is coded using channel coding may be determined. Unlike this, when the terminal transmits control information through the ^2nd SCI in step 610, if it is not transmitted along with data, the ^2nd SCI mapping method 2 can be used in step 612. As described above, the ^2nd SCI mapping method 1 can be considered as a mapping method for solving the power imbalance problem. For example, in Equation 1 above, a large

set the value of

set the value of to 1

By setting the value of 0 to 0, the 2 ^nd SCI can be transmitted so as to be mapped to all regions of the PSSCH. As another example, it can be expressed as Equation 2 below.

[Equation 2]

Through Equation 2, ^2nd SCI can be transmitted so that it is mapped to all regions of PSSCH. In this way, when the mapping method of ^2nd SCI is changed, power imbalance can be solved. Note that in the present disclosure, when the ^2nd SCI is transmitted through the PSSCH, the ^2nd SCI mapping method for solving power imbalance when data is not transmitted in the PSSCH region is not limited to a specific method. However, in the present disclosure, when the UE transmits control information through the 2 ^nd SCI, when an instruction is given for whether the control information is transmitted together with data or not, the corresponding instruction indicates that the 2 ^nd SCI is mapped to the PSSCH differently. Note that you can Specifically, when control information is transmitted through the ^2nd SCI, an indication of whether or not it is transmitted together with data can be indicated by using a reserved one bit in the 1st SCI. Alternatively, a method of indicating whether the corresponding 2 ^nd SCI format is a format transmitted with data or not may be used by using a 2 ^nd SCI format indicator in the 1st SCI. Of course, it is not limited to the above examples.

The following embodiments relate to a method for exchanging information to perform cooperation between terminals and a terminal operation for this method. Note that in the present disclosure, information shared for cooperation between terminals is not limited to specific information. For example, coordination information between terminals may be resource selection assistance information (RSAI). In this case, coordination information between terminals may be named RSAI. Note that the term for coordination information between terminals used in the present invention may be named as another term. In the present invention, a terminal may include both a vehicle terminal and a pedestrian terminal, and may include all types of terminals without being limited to the above example.

First of all, in the first embodiment, an overall procedure for how and when cooperation between UEs can be performed in the sidelink will be described. The second embodiment proposes a method for setting a cooperation method between terminals. Note that coordination information between terminals may vary according to a method of cooperation between terminals. In the third embodiment, a new 2 ^nd SCI format required when indicating information for inter-UE coordination through 2 ^nd SCI is proposed and a method of configuring detailed information included in the format is proposed. . In the fourth to sixth embodiments below, detailed terminal operations according to the cooperation method between each terminal will be described. Note that the following embodiments may be used in combination with each other in the present disclosure.

<First Embodiment>

In the first embodiment, a specific scenario for inter-UE coordination in sidelink is presented through drawings. In addition, the overall procedure for when and how cooperation between terminals can be performed is described.

7 is a diagram illustrating a method of performing inter-UE coordination according to an embodiment of the present disclosure. Here, cooperation between terminals may mean providing an enhanced sidelink service by sharing helpful information between terminals. Information that can be helpful between terminals may include resource selection assistance information (RSAI). For example, when a terminal performing transmission on a sidelink allocates resources through a direct sensing and resource selection procedure (Mode2), or when a terminal performing transmission is within the coverage of a base station (BS), resources are allocated from the base station. can be assigned (Mode1). However, a method in which a terminal receives resource allocation and resource allocation-related information from another terminal through inter-UE coordination may be considered. Alternatively, location information of the terminal may be included as cooperation information between terminals. For example, in order for a specific terminal to measure the absolute position of the terminal, it is necessary to receive a position measurement signal from another terminal as well as to receive absolute position information of the other terminal. In the present disclosure, information shared for cooperation between terminals is not limited to specific information. In the present disclosure, a case in which information necessary for cooperation between terminals is indicated through 2 ^nd SCI is considered, and this information is referred to as coordination information between terminals.

Referring to FIG. 7, a scenario in which inter-UE coordination is performed in a sidelink is shown. In FIG. 7, UE-A 701 corresponds to a UE that provides coordination information between UEs to UE-B 702, and UE-B 702 cooperates with UE-A 701. Corresponds to a terminal receiving information. According to FIG. 7(a), a case in which UE-A 701 corresponds to a destination UE intended for UE-B 702 is illustrated. Unlike this, according to FIG. 7(b), a case where any UE (Any UE) can be the UE-A 701 is illustrated. Specifically, in FIG. 7( b ), a case in which UE-A 701 is not a receiving terminal 703 for UE-B 702 is shown. Through UE-to-UE cooperation, UE-B can receive inter-UE cooperation information from UE-A and can receive assistance in performing sidelink transmission. In the present invention, a terminal providing related information for inter-device cooperation is referred to as UE-A, and a terminal receiving related information for inter-device cooperation is referred to as UE-B.

As shown in FIG. 7, in a sidelink, certain UE(s) may be a UE that provides cooperation information between UEs, such as UE-A, or a UE receiving cooperation information between UEs, such as UE-B. . Also, note that not all terminals need to be terminals that provide resource allocation information, such as UE-A, or terminals that receive resource allocation information, such as UE-B. Specifically, one or more terminals may have qualifications to perform the role of UE-A (or UE-B). However, it is not necessary for all UEs qualified to perform the role of UE-A (or UE-B) to become UE-A (or UE-B). Therefore, UE-A (or UE-B) can 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 vice versa. However, it may not perform the role of UE-A (or UE-B). Therefore, in the following embodiment, when inter-UE coordination is performed in the sidelink, conditions that can be UE-A and conditions that can be UE-B are presented. First of all, at least one or more of the following conditions may be included as a condition for a specific terminal to become a UE-A. In the present invention, the condition for the specific terminal to become UE-A during cooperation between terminals is not limited to the following conditions.

Conditions for a specific UE to become UE-A in cooperation between UEs

* Condition 1: A UE determined as UE-A has the capability to perform inter-UE cooperation.

** In condition 1, the corresponding capability may mean the ability to provide corresponding information to other terminals during cooperation between terminals. In addition, when the corresponding capability is defined, the terminal may report the corresponding capability to the base station (BS) or other terminals. For example, the terminal may perform an operation of reporting the terminal capability of whether cooperation between terminals can be supported to the base station through Uu-RRC or to another terminal through PC5-RRC. Through this, the base station will be able to determine whether cooperation between the terminals is possible by grasping the capability of the corresponding terminal. In addition, through this, the terminal may grasp the capabilities of other terminals, determine whether cooperation between terminals with the corresponding terminal is possible, and determine whether to request cooperation information between terminals.

* Condition 2: In the UE determined as UE-A, cooperation between UEs is enabled.

** In condition 2, whether or not cooperation between devices is activated (enabling/disabling) may be set as a higher layer (or higher layer signaling). For example, whether to activate cooperation between terminals may be (pre-)configurated. At this time, (pre-)configuration can be configured for each resource pool. In the present invention, the method for determining whether inter-device 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 be made of a combination of one or more of the above methods.

* Condition 3: A UE determined as UE-A is set to become UE-A in cooperation between UEs.

** Condition 3 may be set to a higher layer (or higher layer signaling). For example, whether UE-A may be set through (pre-)configuration. At this time, (pre-)configuration can be configured for each resource pool. In the present invention, the method in which the terminal is configured as UE-A is not limited thereto. For example, a method of configuring to play the role of UE-A through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also be made of a combination of one or more of the above methods.

** Condition 3 may be a case where a specific terminal is set as a terminal providing cooperation information between terminals in the groupcast. In this case, the corresponding terminal may be a leader terminal of the group.

* Condition 4: The UE determined to be UE-A is the intended destination UE for UE-B.

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

* Condition 5: The terminal determined to be UE-A determines that the signal reception state for UE-B is not good.

** According to condition 5, when the corresponding terminal receives a signal transmitted by UE-B and the reception state is poor, the corresponding terminal becomes UE-A and can provide cooperation information between terminals to UE-B. Therefore, condition 5 can be applied together with condition 4. At this time, determining that the reception state of the signal transmitted by the UE-B is poor may be determined by a packet error rate or failure to receive consecutive packets. The error rate of packets may be a more statistical criterion, and reception failure of consecutive packets may be a case in which X (≥1) packets continuously fail to be received. Here, the packet may mean PSCCH or PSSCH or both PSCCH and PSSCH. In the present invention, a method for determining that a reception state of a signal for a UE-B is not good by a UE is not limited thereto.

* Condition 6: A UE determined as UE-A has sufficient power to perform inter-UE cooperation.

** Condition 6 is due to the fact that more power consumption may occur because UE-A must provide UE-B with related information by performing inter-UE cooperation. Therefore, only the terminal set to full sensing in Mode2 operation can be limited to being UE-A. In other words, a terminal operating in power saving mode in Mode 2 operation may not correspond to condition 6. Here, the power saving mode may be a terminal set to operate by random selection or partial sensing. Alternatively, UE-A may be limited to only when the battery level of the UE is higher than a set threshold. In the present disclosure, the method in which the UE is configured as UE-A according to the power state is not limited thereto, and the UE may be determined as UE-A based on a predetermined power state regardless of the operation mode of the UE or the battery level of the UE. .

* Condition 7: The UE determined as UE-A is triggered to provide information for cooperation between UEs.

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

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

** According to condition 8, cooperation between terminals can be supported only in unicast. When UE-A and UE-B establish PC5-RRC, information can be exchanged between UEs through PC5-RRC or sidelink MAC-CE.

* Condition 9: It is determined that the terminal determined to be UE-A is in communication range with UE-B.

** According to condition 9, only when it is determined that the UE-B is within the communication range by measuring the distance from the UE-B, it becomes UE-A and can provide inter-UE cooperation information to the UE-B. This is because when the distance between UE-A and UE-B is greater than the communication range, even if UE-A provides inter-UE cooperation information to UE-B, the corresponding information may not be valid. At this time, UE-A can calculate the distance based on the zone ID information transmitted by UE-B, and UE-A determines whether to provide cooperation information between UEs based on communication range requirement information transmitted by UE-B. can decide

* Condition 10: The UE determined as UE-A is lower than the measured CBR (Channel Busy Ratio) or CR (Channel Occupancy Ratio) set threshold.

** According to the condition 10, when the CBR or CR used for congestion control is low, even if UE-A provides inter-UE cooperation information, it may not cause a problem in channel congestion.

Of course, not all of the above conditions must always be satisfied, and some conditions may be excluded by configuration of the base station or between terminals. For example, when only conditions 1 to 9 are satisfied, the terminal may be determined as UE-A, and the terminal excluding conditions 5 and 6 may be determined as UE-A.

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

Conditions for a specific UE to become a UE-B in cooperation between UEs

* Condition 1: For a UE determined as UE-B, cooperation between UEs is enabled.

** In condition 1, whether or not cooperation between devices is activated (enabling/disabling) may be set as a higher layer. For example, whether to activate cooperation between terminals may be (pre-)configurated. At this time, (pre-)configuration can be configured for each resource pool. In the present invention, the method for determining whether inter-device 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 be made of a combination of one or more of the above methods.

* Condition 2: A UE determined as UE-B is configured to become a UE-B in cooperation between UEs.

** Condition 2 above can be set as a higher layer. For example, whether UE-B may be set through (pre-)configuration. At this time, (pre-)configuration can be configured for each resource pool. 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 to play the role of UE-A through PC5-RRC, Sidelink MAC-CE, SCI (1 ^st SCI or 2 ^nd SCI) may be considered. It may also be made of a combination of one or more of the above methods.

* Condition 3: A UE determined as UE-B does not have sufficient power.

** Condition 3 is due to the fact that power consumption can be reduced because resource allocation information is provided from UE-A through inter-UE cooperation and UE-B does not perform sensing for resource selection. Therefore, in Mode 2 operation, terminals configured for partial sensing or random selection can be limited to UE-B. Alternatively, UE-B may be limited to being UE-B only when the battery level of the UE is lower than a set threshold. In the present invention, the method in which the UE is configured as UE-B according to the power state is not limited thereto, and the UE may be determined as UE-B based on a predetermined power state regardless of the operation mode of the UE or the battery level of the UE. .

* Condition 4: The corresponding terminal cannot perform sensing or has insufficient sensing results.

** In Condition 4, a case in which the UE performs sidelink Discontinuous Reception (DRX) may be considered as a case in which the UE cannot perform sensing 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 for cooperation between UEs (resource allocation information) in the DRX active period of UE-B. This is to ensure that UE-B can successfully receive inter-UE cooperation information provided by UE-A.

* Condition 5: A UE determined to be UE-B establishes a unicast link with UE-A.

** According to condition 5 above, cooperation between terminals can be supported only in unicast. When UE-A and UE-B establish PC5-RRC, information can be exchanged between UEs through PC5-RRC or sidelink MAC-CE.

* Condition 6: The UE determined as UE-B requested cooperation information between UEs from another UE.

** According to condition 6, when a UE requests inter-UE cooperation information from another UE, that is, UE-A, it may become UE-B after requesting it. In addition, the corresponding terminal may expect to receive inter-terminal cooperation information from another terminal, that is, UE-A.

Of course, not all of the above conditions must always be satisfied, and some conditions may be excluded by configuration of the base station or between terminals. For example, when only conditions 1 to 4 are satisfied, the terminal may be determined as UE-B, and the terminal excluding condition 3 may be determined as UE-B.

<Second Embodiment>

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

How to cooperate between devices

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

** In 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 TBs (Transport Blocks). Also, the set of resource allocations selected at this time may be resource allocation information suitable (preferred) or unsuitable (non-preferred) for transmission of the UE-B. Alternatively, the set of selected resource allocations may include both suitable resources and unsuitable resources for UE-B transmission. For the detailed operation of the terminal for the method 1, refer to the following embodiment.

* Method 2: UE-A transmits whether there is a resource collision for the resource allocation information indicated by UE-B through SCI as inter-UE cooperation information.

** In the above method 2, the presence or absence of a resource collision in the resource allocation information indicated by the SCI by the UE-B may be the presence or absence of a resource collision detected by the UE-A. Alternatively, it may be an expected or potential resource conflict. In contrast, both resource collisions detected by UE-A and expected/potential resource collisions may be included. For the detailed operation of the terminal for the method 2, refer to the following embodiment.

8 is a diagram illustrating the above-described two methods of cooperation between terminals according to an embodiment of the present disclosure. According to UE-to-UE cooperation method 1 (801), UE-A provides UE-B with set information 803 of time-frequency resource allocation that is suitable (preferred) or unsuitable (non-preferred) for transmission to UE-B. can In contrast, according to method 2 of cooperation between UEs (802), UE-A may provide UE-B with only whether or not resources reserved by UE-B through SCI are suitable. In case of UE-to-UE cooperation method 1, since UE-A needs to signal time-frequency resource allocation set information 803 to UE-B, signaling overhead can be increased compared to UE-to-UE cooperation method 2. In the case of UE-to-UE cooperation method 2, since UE-A signals to UE-B only whether or not the resource reserved by UE-B through SCI is suitable, the suitability may be indicated with, for example, 1-bit information.

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

Conditions for operating as inter-device cooperation method 1

* Condition 1: UE-A is configured to operate in method 1 of cooperation between UEs.

** The condition 1 may be set through (pre-)configuration or may be determined from the upper layer of the terminal to be the inter-device cooperation method 1. In the present disclosure, the method set as inter-device cooperation method 1 is not limited thereto. For example, a method configured as inter-device 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. For details on this, refer to the examples below.

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

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

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

** According to condition 3, method 1 of cooperation between terminals can be supported only in unicast. In the case of UE-to-UE cooperation method 1, it is necessary for UE-A to receive prior information such as UE-B's traffic-related requirements from UE-B. When UE-A and UE-B establish PC5-RRC, information can be exchanged between UEs through PC5-RRC. Of course, not all of the above conditions must always be satisfied, and some conditions may be excluded by configuration of the base station or between terminals.

Next, at least one of the following conditions may be included as a condition for selecting method 2 of cooperation between terminals. In the present invention, it is not limited only to the conditions presented below.

Conditions for operating with inter-device cooperation method 2

* Condition 1: UE-A is configured to operate in method 2 of inter-UE cooperation.

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

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

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

* Condition 3: UE-A receives SCI from UE-B.

** Unlike method 1 of cooperation between devices in condition 3 above, method 2 of cooperation between devices involves UE-A receiving SCI ( ^1st SCI, in other words, PSCCH) from UE-B to determine resource information reserved by UE-B. Only then can it be judged whether it is suitable for this.

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

** Condition 4 may correspond to a case in which the UE-A cannot operate in the inter-UE cooperation method 1. This may correspond to a case where UE-A cannot operate in inter-device cooperation method 1 due to UE capability. In contrast, this may correspond to a case in which corresponding information is no longer valid even when UE-A selects a resource through method 1 of cooperation between UEs due to a delay time generated in cooperation between UEs.

Previously, conditions for UE-A to select one of the two methods were presented when method 1 and method 2 of cooperation between UEs are supported in the sidelink. Of course, not all of the above conditions must always be satisfied, and some conditions may be excluded by configuration of the base station or between terminals.

Hereinafter, for convenience of explanation, in the case of UE-to-UE cooperation method 1, information 1-1 is a set of resource allocation suitable (preferred) for transmission of UE-B selected by UE-A, and transmission of UE-B selected by UE-A The set of resource allocations that are not suitable for (non-preferred) are named information 1-2. In addition, in the case of UE-to-UE cooperation method 2, information 2-1 indicates whether or not there is a resource collision for transmission of UE-B detected by UE-A, which is expected or potential by UE-A. ) Information 2-2 indicates whether resources collide with respect to UE-B transmission. Subsequently, information 1-1 or information 2-1 is collectively referred to as information 1 according to the selected cooperation method between terminals, and information 1-1 or information 2-1 is collectively referred to as information 2 according to the selected cooperation method between terminals.

In the present disclosure, if only one of {Method 1 and Method 2} is supported, one of {Method 1 and Method 2} is set, only one of {Information 1 and Information 2} is supported, or one of {Information 1 and Information 2} There may be cases in which UE-A and UE-B have a common understanding or agreement on the method and information used in cases where it is configured or not. For example, when a cooperation method or supported information configuration between UE-A and UE-B is (pre-)configurated in a resource pool or a cooperation method or supported information is set by PC5-RRC between UEs, the UE - It may be a case where a common understanding or agreement on the method and information used between A and UE-B has been derived in advance.

However, in many cases presented above, for example, UE-A supports/instructs both {Method 1 and Method 2}, or UE-A selects one of {Method 1 and Method 2} under specific conditions, In cases where UE-A supports/instructs both {Information 1 and Information 2} or UE-A selects one of {Information 1 and Information 2} under a specific condition, UE-B determines that UE-A It is necessary to understand what kind of cooperation method and information between terminals is indicated.

In the following embodiment, whether method 1 or method 2 of cooperation between UEs is used, and whether information 1 or information 2 is used in each method 1 and method 2, when mutual understanding or agreement is needed between UE-A and UE-B Offer a solution. In this case, the following alternatives may be considered. Note that this disclosure is not limited to the alternatives below.

* Alternative 1: Indicates information about {Method 1, Method 2} and {Information 1, Information 2} used by UE-A as UE-B.

* Alternative 2: Indicates information about {Method 1, Method 2} and {Information 1, Information 2} that UE-B prefers to UE-A.

* Alternative 3: UE-A and UE-B indicate preferred inter-terminal cooperation methods and information, respectively, and finally select and indicate information on {Method 1, Method 2} and {Information 1, Information 2}.

First alternative 1 can be used in the following cases.

* Case 1-1: When one or more {Method 1, Method 2} and {Information 1, Information 2} are commonly (pre-)configurated in the resource pool.

** An example of the corresponding case is shown in Table 1 below. According to Table 1, a case where both {Method 1 and Method 2} are set to true and available is shown, and a case where both {Information 1 and Information 2} are set to true and available are shown.

* Case 1-2: When one or more {Method 1, Method 2} and {Information 1, Information 2} are set to PC5-RRC

** An example of the corresponding case is shown in Table 1 below. According to Table 1, a case where both {Method 1 and Method 2} are set to true and available is shown, and a case where both {Information 1 and Information 2} are set to true and available are shown.

* Case 1-3: When one or more of {Method 1, Method 2} and {Information 1, Information 2} are (pre-)configurated to UE dedicated to the resource pool.

** An example of the corresponding case is shown in Table 1 below. According to Table 1, the case where both {Method 1 and Method 2} are set to true and available is shown, and the case where both {Information 1 and Information 2} are set to true and available is shown.

* Case 1-4: When one {Method 1, Method 2} and {Information 1, Information 2} are (pre-)configurated to UE dedicated to the resource pool.

** An example of the corresponding case is shown in Table 2 below. According to Table 1, a case in which only one of {Method 1 and Method 2} is selectable is shown, and a case in which only one of {Information 1 and Information 2} is selectable is shown.

In case 1-4, UE-A may indicate to UE-B the {Method 1, Method 2} and {Information 1, Information 2} that are (pre-)configurated UE-specifically. Unlike this, in case 1-1/1-2/1-3, in one or more {Method 1, Method 2} and {Information 1, Information 2}, UE-A determines a cooperation method and information between UEs, and UE-B can be instructed.

This is the first method in which UE-A determines a cooperation method and information between UEs and instructs UE-B. The method in which UE-A determines {Method 1, Method 2} and {Information 1, Information 2} under certain conditions is can be considered Specifically, according to the condition for operating in method 1 or method 2 of cooperation between terminals presented above, the power state and capability of UE-A may be conditions.

As a second method in which UE-A determines a cooperation method and information between UEs and instructs UE-B, a method in which UE-A randomly determines {Method 1, Method 2} and {Information 1, Information 2} may be considered. can As the last method in which UE-A determines cooperation method and information between UEs and instructs UE-B, UE-A determines {Method 1, Method 2} and {Information 1, Information 2} by UE implementation. can be considered Note that the present disclosure is not limited to these three methods.

Next, methods for indicating {Method 1, Method 2} and {Information 1, Information 2} determined by UE-A to UE-B are proposed.

* Method 1-1: Instruction through PC5-RRC or sidelink MAC-CE

* Method 1-2: Instruction through SCI (1 ^st SCI or 2 ^nd SCI)

* Method 1-3: Instruction via PSFCH

In the case of method 1-1, since PC5-RRC or sidelink MAC-CE is supported only in sidelink unicast, it has a disadvantage that it cannot be supported in broadcast or groupcast. In the case of method 1-2, 1 ^st SCI may be indicated using a reserved bit in the existing 1 ^st SCI, or a method of introducing a new 1 ^st SCI may be considered. In the case of method 1-3, the PSFCH resource may be determined in association with the PSCCH or PSSCH received from UE-B, which is a PSCCH (eg, 1 ^st SCI) or PSSCH (eg, 1st SCI) requesting cooperation information between UEs. 2 ^nd SCI). In the above methods, a bit field indicating corresponding information may be determined according to {Method 1, Method 2} and {Information 1, Information 2}. For example, when {Method 1, Method 2} or {Information 1, Information 2} is indicated, the instruction may be made with 1-bit information. Unlike this, when both {Method 1, Method 2} and {Information 1, Information 2} are indicated, 2-bit information may be required. Also, the instruction may be made in a combination of one or more of the above methods. In addition, the method of indicating the corresponding information in the present invention is not limited thereto.

Next, alternative 2 can be used in the following cases.

* Case 2-1: When one or more {Method 1, Method 2} and {Information 1, Information 2} are commonly (pre-)configurated in the resource pool.

** Table 1 shows an example for that case. According to Table 1, a case where both {Method 1 and Method 2} are set to true and available is shown, and a case where both {Information 1 and Information 2} are set to true and available are shown.

* Case 2-2: Including all cases

** Case 2-2 may include both a case where one or more {Method 1, Method 2} and {Information 1, Information 2} are preset and not set.

In the above case 2-1/2-2, UE-B may determine (preferred) {Method 1, Method 2} and {Information 1, Information 2} to be received and instruct UE-A. In addition, UE-A may provide UE-B with information and a method for cooperation between corresponding UEs according to {Method 1, Method 2} and {Information 1, Information 2} instructed by UE-B. The first method for determining (preferred) UE-to-UE cooperation methods and information that UE-B wants to receive from UE-A in one or more of {Method 1, Method 2} and {Information 1, Information 2} is the UE under certain conditions. -B is the method for determining {Method 1, Method 2} and {Information 1, Information 2}. Specifically, according to the condition for operating in the method 1 or method 2 of the UE-to-UE cooperation presented above, the power state and capability of the UE-B may be conditions. As a second method in which UE-B determines (preferred) UE-to-UE cooperation methods and information that UE-B wants to receive from UE-A in one or more of {Method 1, Method 2} and {Information 1, Information 2}, UE-B { Method 1, method 2} and a method of randomly determining {information 1, information 2} may be considered. The final method for determining (preferred) inter-UE cooperation methods and information that UE-B wants to receive from UE-A in one or more of {Method 1, Method 2} and {Information 1, Information 2} is UE-B implemented by the UE. Methods in which -B determines {Method 1, Method 2} and {Information 1, Information 2} may also be considered. Note that the present disclosure is not limited to these three methods.

Next, we propose methods for indicating (preferred) {Method 1, Method 2} and {Information 1, Information 2} to UE-A that UE-B wants to receive.

* Method 2-1: Instruction via PC5-RRC or Sidelink MAC-CE

* Method 2-2: Instruction through SCI (1 ^st SCI or 2 ^nd SCI)

In the case of method 2-1, since PC5-RRC or sidelink MAC-CE is supported only in sidelink unicast, it cannot be supported in broadcast or groupcast. In the case of method 2-2, 1 ^st SCI may be indicated by using a reserved bit in the existing 1 ^st SCI, or a method of introducing a new 1 ^st SCI may be considered. When method 2-2 is used, when corresponding information is indicated through SCI, an indicator requesting cooperation information between terminals may be included together. In the above methods, a bit field indicating corresponding information may be determined according to {Method 1, Method 2} and {Information 1, Information 2}. For example, when {Method 1, Method 2} or {Information 1, Information 2} is indicated, the instruction may be made with 1-bit information. Unlike this, when both {Method 1, Method 2} and {Information 1, Information 2} are indicated, 2-bit information may be required. Also, the instruction may be made in a combination of one or more of the above methods. In addition, the method of indicating the corresponding information in the present invention is not limited thereto.

Next, alternative 3 can be used in the following cases.

* Case 3-1: When applicable to Case 1-1 or Case 1-2 or Case 1-3 above

* Case 3-2: Case 2-1 or Case 2-2 above

According to case 3-1, when UE-A indicates preferred {method 1, method 2} and {information 1, information 2} information to UE-B, and UE-B receives information from UE-A If there are (preferred) {Method 1, Method 2} and {Information 1, Information 2}, UE-A and UE-B identify the preferred UE-to-UE cooperation method and information, so that UE-B can { Method 1, method 2} and information on {information 1, information 2} may be finally selected and instructed to UE-A. In this case, UE-A may provide information and a method for cooperation between UEs to UE-B according to information indicated by UE-B. This is a method in which UE-B finally selects information on {Method 1, Method 2} and {Information 1, Information 2} from UE-A and UE-B's preferred inter-terminal cooperation method and information. Priority information of UE-B may be utilized. Specifically, when UE-A transmission priority is high, UE-A's preferred inter-UE cooperation method and information may take precedence. In contrast, when the transmission priority of UE-B is high, priority may be given to a cooperation method and information between UEs preferred by UE-B. However, note that information other than priority information of UE-A and UE-B may be used as the final method and information selection method in the present invention. For a method for UE-B to indicate the corresponding information to UE-A, refer to Methods 2-1 and 2-2 above.

According to the above case 3-2, when UE-B indicates information on {method 1, method 2} and {information 1, information 2} preferred by UE-A to UE-A, and when UE-A prefers {method 2} 1, method 2} and {information 1, information 2}, UE-A and UE-B determine the preferred inter-terminal cooperation method and information, respectively, so that UE-A can perform {method 1, method 2} and {method 2} Information 1, information 2} can be finally selected and instructed to UE-B. This is a method in which UE-B finally selects information on {Method 1, Method 2} and {Information 1, Information 2} from UE-A and UE-B's preferred inter-terminal cooperation method and information. Priority information of UE-B may be utilized. Specifically, when UE-A transmission priority is high, UE-A's preferred inter-UE cooperation method and information may take precedence. In contrast, when the transmission priority of UE-B is high, priority may be given to a cooperation method and information between UEs preferred by UE-B. However, note that information other than priority information of UE-A and UE-B may be used as the final method and information selection method in the present invention. For a method for UE-A to indicate the corresponding information to UE-B, refer to Methods 1-1 to 1-3 above.

Tables 3 and 4 below show another example of setting cooperation methods and information between UEs in a sidelink. Tables 3 and 4 below show cooperation methods between UEs and a method of (pre-)configurating information into sidelink resource pool information. First, according to Table 3, cooperation between UEs in sidelink can be activated and deactivated (sl-InterUECoordination-r17). If inter-device cooperation is activated, an inter-device cooperation method (sl-InterUECoordinationType-r17) may be set. Method 1 and Method 2 between UEs can be basically designed differently from each other, and the operation when UE-B receives different cooperation information according to Method 1 and Method 2 from one or more UE-A can become complicated. As shown in Table 3, method 1 (sl-Scheme1-r17) or method 2 (sl-Scheme2-r17) can be (pre-)configurated as resource pool information. If method 1 (sl-Scheme1-r17) is set, refer to Table 4 for more detailed method 1 setting method.

Table 4 below shows an example of a detailed setting method for inter-device cooperation method 1. First, in the case of method 1, resource selection assistance information (RSAI) may be preferred (Preferred-Info) or non-preferred (Non-Preferred-Info) resource allocation information. When Method 1 is used, both pieces of information may be set together in the resource pool or only one of the two pieces of information may be set. In addition, when inter-UE cooperation method 1 is used, the bitmap size for indicating resource allocation information suitable (preferred) or unsuitable (non-preferred) for transmission of UE-B is resource pool information (pre-)configuration It can be.

When the corresponding resource allocation information is a set including a plurality of preferred or non-preferred time-frequency resource allocation information, a method of indicating the corresponding time-frequency location using a bitmap may be useful. As the corresponding bitmap size increases, the overhead increases when indicating it. As the corresponding bitmap size decreases, the overhead may decrease when indicating it. may not be able to provide

When the corresponding information is indicated as 2 ^nd SCI, if the total number of bits included in 2 ^nd SCI changes, it is necessary to maintain a constant number of bits because the complexity of detecting this by the receiving terminal increases. Therefore, in the case of (pre-)configuration of the bitmap size in time (sl-TimeBitmapSize-r17) for resource allocation information or the bitmap size in frequency (sl-FreqBitmapSize-r17) for resource allocation information as resource pool information, the corresponding pool Since terminals operating in can assume the same size, it may be possible to more flexibly adjust the amount of cooperation information between terminals by setting the corresponding size as shown in Table 4. Finally, a method in which cooperation information between devices is provided by an explicit request (sl-Scheme1-A) and a method in which specific conditions are satisfied (sl-Scheme1-B) can be considered. Depending on the two methods, the cooperation method between devices can be designed differently, and when the corresponding method exists in the resource pool at the same time, the device operation can become more complicated. A method of (pre-)configuration with selected resource pool information may be considered. Details of the two methods refer to the examples below.

<Third Embodiment>

In the third embodiment, when cooperation between terminals of a sidelink is performed and when control information necessary for performing a cooperation method between terminals is indicated, control information and corresponding control that can be included in the 1 ^st SCI and 2 ^nd SCI by the terminal Explain how to interpret and use information. In particular, it is noted that the present embodiment focuses on a method for indicating resource selection assistance information (RSAI) as cooperation information between terminals. However, note that even when information other than RSAI is indicated for inter-UE cooperation, the control information proposed in this embodiment can be used in a similar manner.

First of all, one or more of the control information included in Table 5 may be considered as control information necessary for performing cooperation between terminals. However, note that the control information required to perform inter-device cooperation in the present invention is not limited to the control information presented in Table 5. For example, Table 5 shows an example in which control information necessary for HARQ operation is not included. This is because the cooperation information between terminals may vary depending on the transmission time, so if the information changes, HARQ combine cannot be performed, and when HARQ feedback and retransmission are performed, a delay in transmission of cooperation information between terminals may occur. attributed to its shortcomings. However, this is just one example, and according to another example, the corresponding information may additionally include information such as HARQ process ID, New data indicator, redundancy version, and HARQ feedback enable/disable indicator for HARQ operation.

In Table 5, Inter-UE coordination (e.g., RSAI) request means control information for requesting cooperation between UEs. Specifically, 1-bit control information is used, and if the information is '1', cooperation information between terminals is requested, and if the information is '0', it can be interpreted as not requesting cooperation information between terminals ( Alternatively, if the corresponding information is '0' or '1', it may be interpreted in the opposite way).

In addition, when the Inter-UE coordination (e.g., RSAI) request field has a specific value (eg, '0' or '1'), inter-UE cooperation feedback information, Inter-UE coordination information (e.g. , RSAI) feedback may also be indicated together. However, if the Inter-UE coordination (e.g., RSAI) request field is '1', it may be constrained that Inter-UE coordination information (e.g., RSAI) feedback, which is cooperation feedback information between UEs, is not transmitted. .

The Inter-UE coordination (eg, RSAI) request field may be included in the 1 ^st SCI or may be included in the 2 ^nd SCI. If the Inter-UE coordination (eg, RSAI) request field is included in the 1 ^st SCI, the use of the reserved bit field of the 1 ^st SCI may be considered. In addition, when the corresponding field is set to '0' and it is indicated that cooperation information between terminals is not requested, the ^2nd SCI format indicated through ^{the 1st} SCI can be interpreted in the same way as before. In contrast, when the corresponding field is set to '1' and it is indicated that cooperation information between terminals is requested, the ^2nd SCI format indicated through ^{the 1st} SCI can be interpreted differently from the existing one. Specifically, referring to Table 6, when it is indicated that cooperation information between terminals is requested, the '00' field is interpreted as being transmitted along with data in the case of SCI format 2-C in which cooperation information between terminals is indicated. In the case where the 01' field is SCI format 2-C in which information related to cooperation between terminals is indicated, it may be interpreted as not being transmitted together with data.

In Table 5, Priority may be priority information for a message requesting cooperation between UEs. Therefore, it may be indicated with a value different from the priority for PSSCH transmission generally included in 1 ^st SCI. As shown in Table 5, when priority information for a message requesting cooperation between terminals is indicated, the UE-A that has received the request for cooperation between terminals prioritizes a terminal having a higher priority and provides cooperation information between terminals. In Table 5, Inter-UE coordination (eg, RSAI) configuration may be control information for indicating whether {Scheme1-Preferred, Scheme1-Non-Preferred} is used in Inter-UE Cooperation Method 1. In Table 5, Inter-UE coordination (eg, RSAI) latency bound may be information for indicating the traffic requirements of UE-B.

Here, the traffic requirement can be interpreted as PDB (packet delay budget). In general, when UE-B selects a transmission resource through sensing, it selects a transmission resource by setting a resource selection window to satisfy PDB. If UE-A does not know the traffic requirements of UE-B, the resource selected by UE-A for UE-B may not satisfy the traffic requirements of UE-B. Therefore, if the corresponding information is provided to UE-A, UE-A will be able to select and feed back an RSAI that satisfies UE-B's traffic requirements. At this time, the Inter-UE coordination (eg, RSAI) latency bound may include the amount of information of A bits, and the corresponding size may be determined as a fixed value or the corresponding size may be (pre-)configurated in the resource pool. In Table 5, Resource size L _subCH means the number of consecutive L _subCH subchannels as a unit of frequency resource selection determined by the UE during sensing and resource selection. If UE-B provides the corresponding value to UE-A, UE-A will be able to select RSAI by reflecting it and provide it to UE-B. However, if UE-B does not provide the corresponding value to UE-A, UE-A may provide UE-B with RSAI with Resource size L _subCH reflected when RSAI is selected. In Table 5, Inter-UE coordination information (eg, RSAI) feedback represents cooperation information between UEs. As mentioned above, in this embodiment, a method of providing RSAI as cooperation information between terminals is described. In this case, three alternatives can be considered: However, the present invention is not limited to the following alternatives.

* Alternative 1: time and frequency bitmap - [X] x [Y] bits

* Alternative 2: time bitmap only - [X] bits

* Alternative 3: Reuse TRA/FRA field in the 1st-stage SCI format (i.e. SCI format 1-A)

In the case of Alternatives 1 and 2, when the UE-to-UE cooperation method 1 described in Embodiment 2 is used, a plurality of time and frequency resource candidates suitable (preferred) or unsuitable (non-preferred) for transmission of UE-B are selected. As a case where a bitmap is used as a method for indicating, the size of the corresponding bitmap may be fixed to a specific value or the size of the bitmap may be (pre-)configurated as resource pool information. In the case of alternative 1, the time and frequency bitmaps are used as X bits and Y bits, respectively, and in the case of alternative 2, only the time bitmaps are used as X bits. When alternative 2 is used, it has the disadvantage of not providing frequency-based resource allocation information, but has the advantage of reducing signaling overhead. In the case of alternative 3, it is a method for selecting and indicating only one or two time and frequency resource information candidates suitable (preferred) or unsuitable (non-preferred) for transmission of UE-B, and indicating resources indicated in the existing 1 ^st SCI. An allocation information indication field and a corresponding indication method may be utilized and used. Specifically, Table 7 shows fields included in the existing 1 ^st SCI format.

In Table 7, the bit information amount of the Frequency resource assignment and Time resource assignment fields can be used as the information amount of the resource allocation information indication field when Alternative 3 is used. In Table 5, Zone ID and Communication range requirement are control information for determining the communication range between terminals, and the terminal can calculate the distance between terminals based on the zone ID information provided by other terminals. It is possible to determine whether the terminal is in a communication range with another terminal. Zone ID and communication range requirement are control information for determining the communication range between terminals, and can be used to feedback RSAI only when it is determined that the distance between terminals is within the communication range or to determine whether the received RSAI is valid. In Table 5, Source ID and Destination ID are used to determine the source and destination of data transmission, and if they are not transmitted together with the ^2nd SCI and data, the Source ID and Destination ID may not be included in the ^2nd SCI.

Next, various methods of indicating the control information included in Table 5 are considered below. First of all, in order to perform inter-device cooperation in the first method, one or more of the control information shown in Table 5 can be included in one ^2nd SCI format, and the corresponding ^2nd SCI is a new format SCI format as shown in the '10' field of Table 8 It can be defined as 2-C.

As a second method, as shown in Table 9 below, control information necessary to request cooperation information between terminals is included in one ^2nd SCI format, and control information necessary to provide cooperation information between terminals is included in another format as shown in Table 10 below. This is a method of including in the ^2nd SCI format. In addition, the corresponding 2 ^nd SCI may be defined in each new format. '10' in Table 11 may be defined as SCI format 2-C indicating control information in Table 9. And '11' of Table 11 may be defined as SCI format 2-D indicating control information of Table 10.

Control information providing cooperation information between terminals

Control information requesting cooperation information between terminals

<The fourth embodiment>

In the fourth embodiment, for providing information when cooperation method 1 between terminals of sidelink is used and when coordination information between terminals is triggered through an explicit request. The detailed operation of the terminal will be described. For a more detailed description of the method 1 of cooperation between terminals, refer to the above embodiment 2.

9 is a diagram for explaining a procedure for performing cooperation between terminals in a sidelink in case of supporting method 1 of cooperation between terminals based on an explicit request according to an embodiment of the present disclosure. Note that FIG. 9 focuses on a method for indicating resource selection assistance information (RSAI) as cooperation information between terminals. However, in the present disclosure, cooperation information between terminals is not limited to RSAI. In other words, note that RSAI in FIG. 9 can be interpreted as meaning general cooperation information between UEs.

Specifically, as shown in FIG. 9 , UE-B 901 may request RSAI 903 to UE-A 902 . For a method of indicating RSAI when requesting it, refer to the third embodiment. Upon receiving a signal for the RSAI request from UE-B, UE-A may perform validation of whether to provide feedback on the corresponding RSAI request in step 904. At this time, validation can be determined from other control information that UE-A receives from UE-B along with RSAI request 903, and other control information that UE-A receives from UE-B along with RSAI request 903. As shown in Table 5 of the third embodiment, may include RSAI latency bound, Zone ID, communication range requirement, and the like. At this time, refer to the third embodiment for a detailed description of determining validity through the corresponding control information. If it is determined in step 904 that providing feedback on the RSAI request is valid, the UE-A moves to step 905 for RSAI transmission. TX resource selection can be performed. Also, moving to step 906, an RSAI for providing RSAI feedback may be determined. As described in Embodiment 2, in method 1 of cooperation between UEs, RSAI may be resource allocation information suitable (preferred) or unsuitable (non-preferred) for transmission of UE-B. In addition, resource allocation information suitable (preferred) or unsuitable (non-preferred) for transmission of UE-B is determined by UE-B and instructed to UE-A, and UE-A determines and instructed to UE-B. You can consider giving.

In step 906, UE-A may determine suitable (preferred) or unsuitable (non-preferred) RSAI, which may be determined from other control information that UE-A receives from UE-B together with the RSAI request 903. and the corresponding control information may include RSAI latency bound, Resource size L _subCH , etc., as shown in Table 5 of Example 3. For a detailed description of this, refer to Example 3.

If UE-A determines the RSAI in step 906, the corresponding information can be provided to UE-B in step 907. At this time, UE-A may provide RSAI configuration (Preferred, Non-Preferred), Zone ID, communication range requirements, etc. as shown in Table 5 of Embodiment 3 along with RSAI feedback information. As shown in FIG. 9, UE-B 901 requests RSAI from UE-A 902 (903), and then provides RSAI information from UE-A within the corresponding time considering the RSAI latency bound (907). If not received, RSAI information may not be expected from UE-A. Specifically, after requesting RSAI (903), the UE-B sets the timer to the RSAI latency bound and decreases the timer so that when the timer expires, RSAI reception may not be expected.

If RSAI information is received from UE-A within the RSAI latency bound (907), it is possible to move to step 908 to check whether the RSAI feedback is valid. At this time, validation can be determined from control information provided by UE-A to UE-B, and the corresponding control information can include Zone ID, communication range requirements, etc. as shown in Table 5 of Example 3. At this time, refer to the third embodiment for a detailed description of determining validity through corresponding control information. When it is determined that the RSAI provided in step 908 is valid, the UE-B moves to step 909 and can determine transmission resources using the RSAI information and the sensing result of UE-B, if available. When transmission resources are determined, UE-B may perform PSCCH/PSSCH transmission in step 910. According to 910 in FIG. 9, PSCCH/PSSCH transmission is shown as being performed to UE-A, but is not limited thereto. In other words, PSCCH/PSSCH transmission may be performed to a terminal other than UE-A.

<Fifth Embodiment>

In the fifth embodiment, a detailed operation of a UE will be described when the method 1 for cooperation between UEs of sidelink is used and when coordination information between UEs is triggered and provided by a specific condition. For a more detailed description of the method 1 of cooperation between terminals, refer to the above embodiment 2.

10 is a diagram for explaining a procedure for performing cooperation between terminals in a sidelink when cooperation between terminals is triggered based on a specific condition according to an embodiment of the present disclosure and cooperation method 1 between terminals is supported. Note that FIG. 10 focuses on a method for indicating resource selection assistance information (RSAI) as cooperation information between terminals. However, in the present disclosure, cooperation information between terminals is not limited to RSAI. In other words, it is noted that RSAI in FIG. 10 can be interpreted as meaning general cooperation information between UEs. In the fifth embodiment, various methods may be considered as a method in which cooperation between terminals is triggered by a specific condition, rather than a method in which cooperation between terminals in the fourth embodiment is triggered by an explicit request. For example, when the condition of becoming UE-A described in the first embodiment is satisfied, cooperation between UEs is triggered, and UE-A may provide cooperation information between UEs. Of course, UE-A may provide cooperation information between UEs when the condition of becoming UE-B is satisfied. Specific conditions may be set by the base station or the UE without being limited to the above example.

In FIG. 10, a dedicated RSAI resource is defined as a specific condition for triggering cooperation between devices, and a method of providing cooperation information between devices by triggering cooperation between devices when the device determines that the dedicated RSAI resource is available is presented in detail.

Specifically, as shown in FIG. 10, a dedicated RSAI resource 1003 may be configured between UE-B 1001 and UE-A 1002. Dedicated RSAI resources can be (pre-)configurated through periodicity and duration settings in the resource pool. Specifically, the value of periodicity (N) may be set to 0 or X logical slot. Here, 0 may mean that a dedicated RSAI resource is not set, and the value of X≥1 may have one or more candidate values. Also, the value of duration(M) may be set to Y≥1 logical slot. The value of Y may have one or more than one candidate value. In this way, when the dedicated RSAI resource is configured and usable, the UE-A may determine whether to transmit cooperation information between UEs using the dedicated RSAI resource in step 1004. This can be done through sensing.

Specifically, energy detection can be performed in an area where dedicated RSAI resources are set, or RSRP (Reference Signal Receiver Power) can be measured on the assumption that DMRS with a fixed pattern is transmitted in areas where dedicated RSAI resources are set. If the energy detection or RSRP measurement result is lower than the set threshold, RSAI transmission can be performed in the dedicated RSAI resource to provide RSAI to UE-B. Otherwise, RSAI cannot be provided to UE-B. .

The operation of sensing the dedicated RSAI resource in step 1004 can be interpreted as a process of checking whether RSAI can be provided to UE-B, and as a result of step 1004, RSAI can be transmitted from the dedicated RSAI resource It can be interpreted that the condition of becoming UE-A is satisfied. Then, the UE-A may move to step 1005 and determine an RSAI for providing RSAI feedback. As described in the second embodiment, in method 1 of cooperation between UEs, RSAI may be resource allocation information suitable (preferred) or unsuitable (non-preferred) for transmission of UE-B. In addition, a method of determining the corresponding information and instructing it to UE-A and a method of determining and instructing the corresponding information to UE-B may be considered. In step 1005, UE-A can determine suitable (preferred) or unsuitable (non-preferred) RSAI. At this time, information that helps UE-A determine RSAI from UE-B (RSAI latency bound, Resource size L _subCH etc.), RSAI can be determined from that information. However, if the corresponding information is not provided, the UE-A must determine the RSAI without the corresponding information.

If UE-A determines the RSAI in step 1005, the corresponding information can be provided to UE-B in step 1006. At this time, UE-A provides RSAI configuration (Preferred, Non-Preferred), RSAI latency bound, Resource size L _subCH , Zone ID, communication range requirements, etc. as shown in Table 5 of the third embodiment along with RSAI feedback information. can give UE-B (1001) may not expect to receive RSAI information from UE-A if RSAI information is not provided (1006) from UE-A within that time considering the RSAI latency bound at the time when the dedicated RSAI resource is set. . Specifically, RSAI reception may not be expected when the timer expires by setting the timer to the RSAI latency bound at the time when the dedicated RSAI resource is set and decreasing the timer.

If RSAI information is received from RSAI latency bound UE-A (1006), it is possible to move to step 1007 to check whether the RSAI feedback is valid. At this time, validation can be determined from control information provided by UE-A to UE-B, and the corresponding control information can include Zone ID, communication range requirements, etc. as shown in Table 5 of Example 3. At this time, refer to the third embodiment for a detailed description of determining validity through corresponding control information. When it is determined that the RSAI provided in step 1007 is valid, the UE-B moves to step 1008 to determine a transmission resource using RSAI information and a sensing result of UE-B, if available. When transmission resources are determined, UE-B may perform PSCCH/PSSCH transmission in step 1009. According to 1009 in FIG. 10 , PSCCH/PSSCH transmission is illustrated as being performed to UE-A, but is not limited thereto. In other words, PSCCH/PSSCH transmission may be performed to a terminal other than UE-A.

<Embodiment 6>

In the sixth embodiment, a detailed operation of a terminal for which coordination information is provided when sidelink method 2 of cooperation between terminals is used will be described. A more detailed description of method 2 of cooperation between terminals is See Example 2.

11 is a diagram for explaining a procedure for performing cooperation between terminals in a sidelink when cooperation method 2 between terminals according to an embodiment of the present disclosure is used. Note that FIG. 11 focuses on a method for indicating resource selection assistance information (RSAI) as cooperation information between terminals. However, the present invention does not limit cooperation information between terminals to RSAI. In other words, it is noted that RSAI in FIG. 11 can be interpreted as meaning general cooperation information between UEs. In FIG. 11, a method of reusing a HARQ feedback method through PSFCH resource configuration and PSFCH resource when the UE provides RSAI is specifically presented.

Specifically, as shown in FIG. 11, a PSFCH resource 1103 may be configured between UE-B 1101 and UE-A 1102. PSFCH resources can be (pre-)configurated through periodicity settings in the resource pool. Specifically, the value of periodicity (N) may be set to 0 or X logical slot. Here, 0 may mean that the PSFCH resource is not configured and may be set to one of the values of X = 1, 2, or 4. In this way, when the PSFCH resource is set and available in the resource pool, and when the resource pool is set to use method 2 for cooperation between UEs as described in the second embodiment, and UE-B performs SCI through step 1104 When (Sidelink Control Information) is transmitted and UE-A receives it, method 2 of cooperation between UEs may be performed by reusing PSFCH resource configuration and HARQ feedback method.

In other words, it is assumed that HARQ feedback through PSFCH resources is not used when inter-device cooperation method 2 is used according to the method of FIG. 11 . Therefore, when UE-B transmits SCI through step 1104, the HARQ feedback enable/disable indicator included in the ^2nd SCI is replaced with an RSAI feedback enable/disable indicator, and UE-B transmits RSAI to UE-A through the corresponding indicator. An operation of requesting (RSAI feedback enable) or not requesting (RSAI feedback disable) may be performed.

In addition, when the existing SCI format 2-B is used, UE-B transmits the SCI in step 1104 and UE-A receives it, in step 1105, Zone ID and communication range requirement information included in the SCI format 2-B are transmitted. RSAI may not be fed back when the distance between UE-A and UE-B is greater than the communication range. If UE-A determines that the RSAI feedback is valid in step 1105, the UE-A moves to step 1106 and may determine an RSAI for providing RSAI feedback.

In method 2 of UE-to-UE cooperation, UE-A identifies the resource allocation information included in the SCI received from UE-B, that is, the ^1st SCI, and determines whether a resource collision can occur with respect to the resource allocation information reserved by UE-B. RSAI can be determined by determining whether or not. Specifically, RSAI can be fed back through PSFCH, and ACK of HARQ feedback indicates that resource collision does not occur, and NACK of HARQ feedback can indicate that resource collision occurs. When UE-B receives RSAI information from UE-A (1107), it moves to step 1108. If RSAI indicates resource collision, UE-B cancels the reserved transmission resources and reselects transmission resources, and returns to step 1109. In step, PSCCH / PSSCH transmission may be performed. According to 1109 in FIG. 11, it is shown that PSCCH/PSSCH transmission is performed to UE-A, but is not limited thereto. In other words, PSCCH/PSSCH transmission may be performed to a terminal other than UE-A.

In order to perform the above embodiments of the present invention, a transmitting unit, a receiving unit, and a processing unit of a terminal and a base station are shown in FIGS. 12 and 13, respectively. In the above embodiments, a method for a terminal to perform cooperation between terminals in a sidelink is shown, and to perform this, a receiving unit, a processing unit, and a transmitting unit of the base station and the terminal must respectively operate according to the embodiment.

Specifically, FIG. 12 is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention. As shown in FIG. 12, the terminal of the present invention may include a terminal receiving unit 1200, a terminal transmitting unit 1204, and a terminal processing unit 1202. Of course, it is not limited to the above example, and the terminal may include more or fewer components than the configuration of FIG. 12 . In addition, the terminal receiving unit 1200, the terminal transmitting unit 1204, and the terminal processing unit 1202 may be implemented as a single chip.

The terminal receiver 1200 and the terminal transmitter 1204 may be collectively referred to as a transceiver in an embodiment of the present invention. The transmitting/receiving unit may transmit/receive signals with other terminals and/or base stations. Signals transmitted and received with other terminals and/or base stations may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of a transmitted signal, and an RF receiver for low-noise amplifying a received signal and down-converting its frequency. In addition, the transmitting/receiving unit may receive a signal through a wireless channel, output the signal to the terminal processing unit 1202, and transmit the signal output from the terminal processing unit 1202 through the wireless channel. The terminal processing unit 1202 may control a series of processes so that the terminal can operate according to the above-described embodiment of the present invention. In addition, the terminal may further include a storage unit (not shown), and the storage unit may store programs and data required for operation of the terminal. Also, the storage unit may store control information or data included in a signal obtained from the terminal. The storage unit may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Also, the storage unit may be composed of a plurality of memories.

13 is a block diagram showing the internal structure of a base station according to an embodiment of the present invention. As shown in FIG. 13, the base station of the present invention may include a base station receiving unit 1301, a base station transmitting unit 1305, and a base station processing unit 1303. Of course, it is not limited to the above example, and the base station may include more or fewer components than the configuration of FIG. 13 . In addition, the base station receiving unit 1301, the base station transmitting unit 1305, and the base station processing unit 1303 may be implemented in a single chip form.

The base station receiving unit 1301 and the base station transmitting unit 1305 may collectively be referred to as transceivers in an embodiment of the present invention. The transmitting/receiving unit may transmit/receive signals to/from the terminal and/or other base stations. Signals transmitted and received with the terminal and/or other base stations may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of a transmitted signal, and an RF receiver for low-noise amplifying a received signal and down-converting its frequency. In addition, the transceiver may receive a signal through a radio channel, output the signal to the base station processor 1303, and transmit the signal output from the base station processor 1303 through a radio channel. The base station processing unit 1303 can control a series of processes so that the base station can operate according to the above-described embodiment of the present invention.

In addition, the base station may further include a storage unit (not shown), and the storage unit may store programs and data required for operation of the terminal. Also, the storage unit may store control information or data included in a signal obtained from the terminal. The storage unit may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Also, the storage unit may be composed of a plurality of memories.

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 content of the present invention and help understanding of the present invention, and are not intended to limit the scope of the present invention. That is, it is obvious to those skilled in the art that other modifications based on the technical idea of the present invention can be implemented. In addition, each of the above embodiments can 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.

Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

Such programs (software modules, software) may include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (EEPROM: Electrically Erasable Programmable Read Only Memory), magnetic disc storage device, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of It can be stored on optical storage devices, magnetic cassettes. Alternatively, it may be stored in a memory composed of a combination of some or all of these. In addition, each configuration memory may include a plurality.

In addition, the program accesses through a communication network such as the Internet, an Intranet, a Local Area Network (LAN), a Wide LAN (WLAN), or a Storage Area Network (SAN), or a communication network composed of a combination thereof. It can be stored on an attachable storage device that can be accessed. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. In addition, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in singular or plural numbers according to the specific embodiments presented. However, the singular or plural expressions are selected appropriately for the presented situation for convenience of description, and the present invention is not limited to singular or plural components, and even if the components expressed in plural are composed of a singular number or singular Even the expressed components may be composed of a plurality.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments and should not be defined, but should be defined by not only the scope of the claims to be described later, but also those equivalent to the scope of these claims. For example, a base station and a terminal may be operated by combining parts of one embodiment of the present disclosure and another embodiment. In addition, the embodiments of the present disclosure can be applied to other communication systems, and other modifications based on the technical ideas of the embodiments may also be implemented.

Claims (1)

In the cooperation information providing method of the first terminal,
Receiving a message requesting resource selection assistance information (RSAI) to be used for communication of the second terminal from a second terminal;
Determining whether to provide feedback information for the RSAI request based on the message;
determining the RSAI based on the determination result; and
And transmitting feedback information including the determined RSAI to the second terminal.

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