KR20230108187A - A method and an apparatus for resource allocation in vehicle-to-everything system - Google Patents

Abstract

The present disclosure relates to a communication technique and a system for converging a 5G communication system with IoT technology to support a higher data rate after a 4G system. The present disclosure provides intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, security and safety related services, etc.) based on 5G communication technology and IoT related technology. ) can be applied. In particular, the present disclosure relates to a method and apparatus for allocating resources in a process in which a vehicle terminal supporting vehicle-to-everything (V2X) transmits and receives information with another vehicle terminal and a pedestrian portable terminal using a sidelink. will be.

Description

Method and device for allocating resources in V2X system {A METHOD AND AN APPARATUS FOR RESOURCE ALLOCATION IN VEHICLE-TO-EVERYTHING SYSTEM}

The present invention relates to a wireless mobile communication system, and more particularly, in a process in which a vehicle terminal supporting vehicle-to-everything (V2X) transmits and receives information with other vehicle terminals and pedestrian portable terminals using a side link. It relates to a method and apparatus for allocating.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system to meet the growing demand for wireless data traffic after the commercialization of the 4G communication system. 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 achieve a high data rate, the 5G communication system is being considered for implementation in a mmWave band (eg, 60 gigabytes (80 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, 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, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation etc. are 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), and the like are being developed.

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 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 (5th generation communication system or New Radio (NR)) 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 3eG technology and IoT technology.

As various services can be provided according to the above and the development of wireless communication systems, a method for smoothly providing these services is required.

The present invention relates to a wireless communication system, and relates to a method and apparatus for performing resource allocation in a process in which a vehicle terminal supporting V2X exchanges information with another vehicle terminal and a pedestrian portable terminal using a side link. In particular, it relates to a resource selection method when discontinuous reception (DRX) is performed between terminals. It also relates to a resource selection method through cooperation between terminals.

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

The present invention is to propose a resource selection method when discontinuous reception (DRX) is performed between terminals in sidelink communication. In addition, it is to propose a resource selection method through cooperation between terminals. The proposed method can be applied and effectively used to minimize the power consumption of the terminal. In addition, the performance of resource allocation can be improved through the proposed method.

1 is a diagram illustrating an example of a communication system to which an embodiment of the present disclosure may be applied.
2 is a diagram illustrating a V2X communication method through a sidelink according to an embodiment of the present disclosure.
3 is a diagram for explaining a resource pool defined as a set (set) of resources on time and frequency used for sidelink transmission and reception according to an embodiment of the present disclosure.
4 is a sequence 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 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.
6 is a diagram illustrating a mapping structure of physical channels mapped to one slot in a sidelink according to an embodiment of the present disclosure.
7 is a diagram illustrating a sensing window (sensing widow) and a resource selection window (resource selection window) required for a terminal to (re)select and reevaluate resources for resource allocation in a sidelink when operating in full sensing according to an embodiment of the present disclosure. It is a drawing for defining a selection widow).
8 is a diagram illustrating a method of performing partial sensing for periodic transmission in a sidelink according to an embodiment of the present disclosure.
9 is a diagram illustrating a method of performing partial sensing for aperiodic transmission in a sidelink according to an embodiment of the present disclosure.
10 is a diagram illustrating a method of performing cooperation between terminals according to an embodiment of the present disclosure.
11 illustrates an inactive time (or off-duration) and an active time of DRX determined according to parameters set for DRX when discontinuous reception (hereinafter referred to as DRX) is performed in a sidelink according to an embodiment of the present disclosure. (or on-duration).
12 is a diagram illustrating a method of operating a UE for sensing and resource selection when DRX is performed in a sidelink according to an embodiment of the present disclosure.
13 is a diagram illustrating a resource selection window during Mode2 operation of a peer terminal transmitting sidelink data to a terminal performing DRX according to an embodiment of the present disclosure.
14 is a diagram illustrating an example of a resource selection method when a peer terminal transmits sidelink data to a terminal performing DRX according to an embodiment of the present disclosure.
15 is a diagram illustrating a method of transmitting cooperation information of a terminal according to information for cooperation between terminals.
16 is a block diagram showing the configuration of a terminal according to an embodiment of the present invention.
17 is a block diagram showing the configuration of a base station according to an embodiment of the present disclosure.
18 is a diagram illustrating a terminal operation according to whether a TX terminal performs periodic transmission 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 performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is 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 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, 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 sidelink, inter-UE coordination may be considered. Here, cooperation between terminals may mean providing a more improved sidelink service by sharing helpful information between terminals. In the present invention, information shared for cooperation between terminals is not limited to specific information. For example, this information may include resource selection assistance information (hereinafter referred to as RSAI). The present invention provides various methods for a terminal to request or provide cooperation information between terminals.

In particular, in sidelink communication, discontinuous reception (DRX) between terminals may be considered. When DRX is applied, battery efficiency can be increased by minimizing power consumption of the terminal. Specifically, the power consumed by the terminal may be generated in the following process.

* Decoding of control information 1 ^st SCI transmitted through PSCCH: 1 ^st SCI includes UE scheduling information, and the information can be used to perform sensing by decoding 1 ^st SCI

* Decoding of control information ^2nd SCI transmitted through PSSCH: ^2nd SCI includes other control information not included in ^1st SCI

* Decoding of data transmitted over the PSSCH

Therefore, in a time interval set as an inactive time when DRX is applied to the sidelink, the UE may not perform decoding of the control information and data information. Unlike this, the terminal can perform decoding on the control information and data information only in the time interval set as the active time when DRX is applied. Therefore, in the sidelink, the transmitting terminal must transmit data in the section set as the DRX active time of the receiving terminal, but successful data reception of the receiving terminal can be guaranteed. In other words, when the transmitting terminal transmits data in a section set as the DRX inactive time of the receiving terminal in the sidelink, the receiving terminal may not receive a corresponding signal. In consideration of this point, the present invention proposes methods for performing resource selection by a transmitting terminal.

Embodiments of the present specification are proposed to support the above scenario, and in particular, an object of providing a method and apparatus for performing multi-antenna transmission in a sidelink.

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

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 shows 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, the SIB may be an existing SIB or a separately defined SIB for V2X. 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, 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, such 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 number 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.

A resource granularity on the 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. In addition, slots belonging to the resource pool exclude slots in which a Sidelink Synchronization Signal Block (S-SSB) is transmitted. Referring to 301, except for these slots, the set (set) of slots that can be used as sidelinks in time ( , , ,...). Colored parts in 301 represent sidelink slots belonging to the resource pool. Sidelink slots belonging to a resource pool may be (pre-)configurated with resource pool information through a bitmap. Referring to 302, the set (set) of sidelink slots belonging to the resource pool in time ( , , ,...). In the present invention, the meaning of (pre-)configuration may mean pre-configuration and pre-stored configuration information in a terminal, or may mean a case where a terminal is configured in a cell-common way 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. 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). The 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. there is.

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). In contrast, when the receiving terminal 402 is located outside the coverage of the base station (cell) 403, the receiving terminal 402 may not camp on the base station (cell) 403.

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

The transmitting terminal 401 and the receiving terminal 402 may receive a sidelink system information block (SL-SIB) from the base station 403 (410). The SL-SIB information includes sidelink resource pool information for sidelink transmission and reception, parameter setting information for sensing operation, information for setting sidelink synchronization, or carriers for sidelink transmission and reception operating at different frequencies. information 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). Here, the RRC connection between the terminal and the base station may be referred to as Uu-RRC. The Uu-RRC connection process 420 may be performed before data traffic 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 perform transmission 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 by the configured grant method, the transmission time (occasion) and frequency allocation location of initial transmission and retransmission for one TB can be determined by the DCI, and resources for the next TB can be repeated at SPS interval intervals there is. 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). The 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. there is. Also, referring to FIG. 5, unlike in 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 located within the base station (cell) You can camp on (503) (507). In contrast, 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 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. can be included

The difference between FIG. 4 and FIG. 5 is that in FIG. 4, the base station 503 and the terminal 501 operate in an RRC connected state, whereas in FIG. 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 physical channels mapped to one slot in a sidelink according to an embodiment of the present disclosure.

Specifically, mapping of PSCCH/PSSCH/PSFCH physical channels 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. In this case, a resource in time through 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. In addition, 1, 2, and 4 may mean that PSFCH resources are transmitted in every 1, 2, and 4 slots, respectively. In FIG. 6 (a), the structure of a slot in which PSFCH resources are not set is shown, and in FIG. 6 (b), the structure of slots in which PSFCH resources are set is shown. 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 mapping of PSCCH/PSSCH/PSFCH in time, one or more symbols before the transmitting terminal transmits PSCCH/PSSCH/PSFCH in the corresponding slot 601 are transferred to the AGC region 602. can be used When the corresponding symbol(s) is used for AGC, a method of repeatedly transmitting a signal of another channel in the corresponding symbol region may be considered. In this case, a part of a PSCCH symbol or a PSSCH symbol may be considered as a repeated signal of another channel. Alternatively, a preamble may be transmitted in the AGC region. When the preamble signal is transmitted, there is an advantage in that the AGC execution time can be further shortened than the method of repeatedly transmitting signals of other channels. When a preamble signal is transmitted for AGC, a specific sequence may be used as the preamble signal 602, and at this time, sequences such as PSSCH DMRS, PSCCH DMRS, and CSI-RS may be used as the preamble. The sequence used as the preamble in the present disclosure is not limited to the above-described example. Additionally, according to FIG. 6, control information related to resource allocation in the initial symbols of the slot is transmitted to the PSCCH 603 as 1st stage SCI (sidelink control information), and other control information is transmitted as 2nd stage SCI in the area 604 of the PSSCH. can be sent to Data scheduled by the control information may be transmitted through the PSSCH 605 . In this case, the position in time at which the 2nd stage SCI is transmitted may be mapped from a symbol through which the first PSSCH DMRS 606 is transmitted. The position in time at which the PSSCH DMRS 606 is transmitted may be different between a slot in which the PSFCH is transmitted and a slot in which the PSFCH is not transmitted, as shown in FIGS. 6 (a) and 6 (b). 6(a) shows that a physical sidelink feedback channel (PSFCH 607), which is a physical channel for transmitting feedback information, is located at the last part of a slot. A predetermined free time (Guard) is secured between the PSSCH 605 and the PSFCH 607 so that the terminal that has transmitted and received the PSSCH 605 can prepare to transmit or receive the PSFCH 607. . In addition, after transmitting and receiving the PSFCH 607, an empty guard can be secured for a certain period of time.

7 is a diagram illustrating a sensing window (sensing widow) and a resource selection window (resource selection window) required for a terminal to (re)select and reevaluate resources for resource allocation in a sidelink when operating in full sensing according to an embodiment of the present disclosure. It is a drawing for defining a selection widow).

When triggering for resource (re)selection is performed at time point n, the sensing window 701 may be defined as [nT ₀ , nT _proc,0 ]. Here, T ₀ is the starting point of the sensing window and can be (pre-)configurated as resource pool information. T ₀ may be defined as a positive integer in ms. The present disclosure does not limit T ₀ to a specific value. Also, T _proc,0 may be defined as a time required to process a sensed result. The present disclosure does not limit the value set to T _proc,0 to a specific value. For example, T _proc,0 can be defined as a positive integer in ms or in units of slots.

Next, when triggering for resource (re)selection is performed at time n, the resource selection window 702 may be determined as [n+T ₁ , n+T ₂ ]. Here, T ₁ is a value in units of slots and may be selected by a terminal implementation for T ₁ ≤ T _proc,1 . T _proc,1 may be defined as the maximum reference value considering the processing time required to select a resource. For example, T _proc,1 may be defined as a different value according to Subcarrier Spacing (SCS) in units of slots. The present disclosure does not limit the value set to T _proc,1 to a specific value. In addition, T ₂ is a value in units of slots, and can be selected by the terminal within a range satisfying T _2min ≤ _{T 2} ≤ Remaining Packet Delay Budget (PDB). Here, T _{2 min} is to prevent the terminal from selecting too small a value of T ₂ . Here, the T _2min value may be set in the upper layer as 'T _2min (prio _TX )' according to the priority (prio _TX ) and SCS of the transmitting terminal. The terminal may select a transmission resource in the resource selection window 702.

In FIG. 7, triggering for resource (re-)selection is performed at time point n, and triggering for re-evaluation and pre-emption is performed by continuously performing sensing even after time point n is n' An example made in (n'>n) is shown. Specifically, when triggering for resource (re)selection is made at time point n and transmission resources are selected, sensing is continuously performed and it is determined that the selected resources are not suitable for transmission, at time point n' (n'>n). Re-evaluation can be triggered. In addition, pre-emption is when the resource reserved by the terminal overlaps with the resource reserved by another terminal, when the priority of the resource reserved by the other terminal is high and the interference for the corresponding resource is measured high, time point n' (n'> n ), pre-emption may be triggered. In this case, the resource 703 selected and reserved by resource (re)selection at time n may be changed to another resource (706). 7 shows a sensing window 704 and a resource selection window 705 for a time point n' (n'>n) at which re-evaluation and pre-emption are triggered.

8 to 9 illustrate a method of performing partial sensing in a sidelink according to an embodiment of the present disclosure. Unlike full sensing in FIG. 7 , in FIGS. 8 and 9 , different methods for determining slots for performing sensing are illustrated when the terminal operates in partial sensing. However, note that the present invention is not limited to the method presented through FIGS. 8 and 9 . Note that when partial sensing is performed in FIGS. 8 to 9 , the resource selection windows 801 to 901 may be determined as described through 702 in FIG. 7 .

Referring first to FIG. 8 , one method of performing partial sensing is presented. The method presented through FIG. 8 may correspond to a partial sensing method performed when periodic resource reservation is performed. In other words, it is a partial sensing method for periodic transmission. However, note that the method presented through FIG. 8 may be referred to by other terms. Referring to FIG. 8, Y (≥1) candidate slots may be selected in a resource selection window (801, RSW). In this case, the Y candidate slots may be selected continuously or non-contiguously in time in the resource selection window. The minimum value of Y can be (pre-)configurated. The final selection of the Y value and which slot to select may be determined by the terminal implementation. At this time, one of the Y candidate slots is as shown in (802). can be defined as As described through Figure 3 may indicate a sidelink slot belonging to a resource pool. At this time, the slot performing the sensing is can be determined by The corresponding sensing method may be named Periodic Based Partial Sensing (PBPS). vector here represents Y candidate slots, and if it is one slot, it may be expressed as y as shown in FIG. 8. vector is a value corresponding to a periodic reservation interval, and may include one or more values, and in case of one value, as shown in FIG. can be expressed as The value included in can be determined from sl-ResoureReservePeriodList, which is a list of (Pre-)configurated periodic reservation intervals in the resource pool, and the following methods can be considered. Note, however, that the present invention is not limited to the method below.

* Method 1: All values included in sl-ResoureReservePeriodList are used

* Method 2: Only a subset of the values included in sl-ResoureReservePeriodList is used

* Method 3: The common divisor of the values included in sl-ResoureReservePeriodList is used

also vector from is a value that determines the number of slots that perform partial sensing. The interval between sensing slots can be determined by the reservation interval included in . In FIG. 8, the case where k is 1 and the case where k is 2 is two value class was shown about As a method of determining k, it can be basically assumed that k = 1. However, it can be (pre-)configurated so that k=2. However, even in the case of k=2, if the sensing slot exceeds T ₀ as in the case of 803 shown in FIG. 8, the corresponding slot may not be monitored. Also, as shown in FIG. 8 , Continuous Partial Sensing (CPS) may be additionally performed in 804 . Window where CPS is performed [n+ , n+ ] corresponds to the first slot in time among Y candidate slots. Transfer based on (805) Move from slots corresponding to logical slots It can be defined as a time interval corresponding to . here The value of may be assumed to be 31 by default, and a specific value may be (pre-)configurated. if In the case of (pre-)configuration, it can be assumed that CPS is not performed.

Referring to FIG. 9, another method of performing partial sensing is presented. The method presented through FIG. 9 is a partial sensing method for non-periodic transmission rather than partial sensing for periodic transmission shown in FIG. 8 and can be applied to a case where periodic resource reservation is not performed. Unlike FIG. 8, Y'(≥1) candidate slots may be selected in the resource selection window 901 (RSW). In this case, the Y' number of candidate slots may be selected sequentially or non-contiguously in time in the resource selection window. The minimum value of Y' can be (pre-)configurated. The final selection of the Y' value and which slot to select may be determined by the terminal implementation. At this time, one slot among the Y' number of candidate slots is as shown in (902). can be defined as As described through Figure 3 may indicate a sidelink slot belonging to a resource pool. At this time, the slot for performing the sensing is the same as in FIG. can be determined by The corresponding sensing method may be named Periodic Based Partial Sensing (PBPS). Also, as shown in FIG. 9 , Continuous Partial Sensing (CPS) may be additionally performed in 903 . Window where CPS is performed [n+ , n+ ] corresponds to the first slot in time among Y candidate slots. Transferred based on (904) Move from slots corresponding to logical slots It can be defined as a time interval corresponding to . here The value of may be assumed to be 31 by default, and a specific value may be (pre-)configurated. if In the case of (pre-)configuration, it can be assumed that CPS is not performed. However, unlike in FIG. 8, the starting point of the CPS window may be limited to slot n or later.

10 is a diagram illustrating two methods of performing cooperation between terminals according to an embodiment of the present disclosure.

According to UE-to-UE cooperation method 1 (1001), UE-A provides UE-B with suitable (preferred) or unsuitable (non-preferred) time-frequency resource allocation set information 1003 for transmission to UE-B. can In contrast, according to method 2 of cooperation between UEs (1002), 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 the time-frequency resource allocation set information 1003 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.

11 illustrates an inactive time (or off-duration) and an active time of DRX determined according to parameters set for DRX when discontinuous reception (hereinafter referred to as DRX) is performed in a sidelink according to an embodiment of the present disclosure. (or on-duration). The terminal may perform decoding of control information and data information for data reception in a section corresponding to the active time of DRX. Unlike this, decoding of data reception control information and data information may not be performed in a section corresponding to the inactive time of DRX. In the sidelink, there are ^1st SCI, which is control information transmitted through PSCCH, and ^2nd SCI, which is control information transmitted through PSSCH. Also, data information may be transmitted through the PSSCH. It can be assumed that control information and data information are always transmitted simultaneously in the sidelink. Accordingly, a time point (slot) at which control information is received may be the same as a time point (slot) at which data information is received.

The following may be considered as parameters for determining the inactive time and active time for sidelink DRX. However, note that the parameters for determining the inactive time and active time of DRX in the present invention are not limited to the parameters presented below. Also note that some of the parameters below may not be used in sidelink DRX.

DRX related parameters

* drx-cycle

** Indicates the period to which DRX is applied, and the start position (drx-StartOffset) of drx-cycle (1101) can be set. As shown in FIG. 11, a section of inactive time (1110) and active time (1111) can be set within the drx-cycle. A drx-cycle having a long cycle and a short cycle can be set in the sidelink.

* drx-onDurationTimer

** This is the time operating in the active time (or on-duration) of DRX in drx-cycle (1101), and may correspond to active time (1110) of DRX until drx-onDurationTimer (1102) operates and expires. From the time drx-onDurationTimer (1102) expires, the rest of the drx-cycle (1101) can be inactive time (1111) of DRX. An example of a case where only drx-onDurationTimer (1102) is defined in sidelink and DRX inactive time (1110) and active time (1111) are operated is shown in FIG. 11(a).

* drx-InactivityTimer

** If sidelink control information is received (1103) before drx-onDurationTimer (1102) expires within drx-cycle (1101), DRX is active from the time control information is received until drx-InactivityTimer (1104) operates and expires. time may be extended (1110). From the time drx-InactivityTimer (1104) expires, the rest of the drx-cycle (1101) can be DRX inactive time (1111). An example of a case where drx-onDurationTimer (1102) and drx-InactivityTimer (1104) are defined in sidelink and DRX inactive time (1110) and active time (1111) are operated is shown in FIG. 11(b).

* drx-HARQ-RTT-Timer

** When retransmission is performed in the sidelink, the UE may trigger the drx-HARQ-RTT-Timer (1105) within the DRX active time (1111) (1103). The triggering condition of the drx-HARQ-RTT-Timer 1105 in the sidelink is when sidelink control information is received or sidelink control information is received and location information for retransmission is indicated in the sidelink control information (1 ^st SCI). In this case, drx-HARQ-RTT-Timer 1105 may be applied until the next retransmission is received according to corresponding information. When the drx-HARQ-RTT-Timer (1105) expires, the UE can operate in active time (1111) of DRX to receive retransmission. In this case, the active time (1111) of DRX can be a period in which drx-RetransmissionTimer (1106) operates. For details on this, see below. As described above, since the location information of the initial transmission and retransmission resources (including the presence/absence of retransmission resources) is indicated in the ^1st SCI, the drx-HARQ-RTT-Timer 1105 is used for initial transmission and retransmission indicated by the ^1st SCI. It may be assumed and defined as a time gap between resources or a time gap between retransmission resources. If it is indicated that there is no retransmission resource in the received 1 ^st SCI, the drx-HARQ-RTT-Timer 1105 may not operate. In sidelink, drx-onDurationTimer(1102), drx-InactivityTimer(1104), drx-HARQ-RTT-Timer(1105), and drx-RetransmissionTimer(1106) are defined, and DRX inactive time(1110) and active time(1111) ) is shown in FIG. 11 (c).

* drx-RetransmissionTimer

** When retransmission is performed in the sidelink, the drx-RetransmissionTimer 1106 may operate from the time when the drx-HARQ-RTT-Timer 1105 expires. Therefore, drx-RetransmissionTimer does not operate during the time period in which drx-HARQ-RTT-Timer 1105 operates. Also, in the sidelink, drx-RetransmissionTimer 1106 may be determined as a fixed value of one slot or one subframe. In this case, drx-RetransmissionTimer 1105 may not be defined. The present invention is not limited thereto. That is, in the sidelink, drx-RetransmissionTimer may be set to one or more slots or one or more subframe values. Therefore, as shown in FIG. 11(c), the period in which the drx-RetransmissionTimer (1106) operates is set as the active time (1112) of DRX and can receive retransmission from the peer terminal. In addition, the remaining drx-cycle period is set as DRX inactive time (1113), so that the terminal may not perform control and data information reception.

* drx-SlotOffset

** When various SCS (Subcarrier Spacing) is supported, it can be used for the purpose of adjusting the starting position to which sidelink DRX is applied.

* WUS (wake-up signal) cycle

** When WUS is used in sidelink, a WUS cycle can be set. Assuming that WUS is transmitted according to the WUS cycle, the UE may monitor the WUS at a location where the WUS is transmitted (1107). Referring to FIG. 11(d), an example in which a wake-up signal (WUS) is used to determine an inactive time and an active time of DRX is illustrated. As shown in FIG. 11(d), when WUS indicates that the terminal does not wake up in 1107, the terminal does not operate drx-onDurationTimer (1102) in drx-cycle (1101) and all drx-cycle intervals are inactive time of DRX ( 1110) can be set. In contrast, when the WUS indicates that the UE wakes up in 1107, the UE may perform an operation as shown in FIG. 11(a), 11(b), or 11(c) according to the set DRX parameter.

According to the above description, active time (or on-duration) in DRX may be defined as the following condition.

* When a DRX cycle is configured in the sidelink, the active time (or on-duration) may include the following.

** When drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimer is running

As mentioned earlier, some of the above parameters may not be used in sidelink DRX. Alternatively, other parameters may be additionally considered. Note that this may vary depending on the transmission method of sidelink broadcast, unicast, or groupcast. Also, in the present invention, the setting method of the parameter information is not limited to a specific method. Corresponding information may be (pre-)configurated or, in the case of unicast, may be configured through PC5-RRC or sidelink MAC-CE.

In the present invention, a mode 2 sensing and resource selection method of a UE is proposed when DRX is operated in a sidelink through the following embodiments (refer to FIG. 11). In addition, a cooperation method between terminals in sidelink is also proposed.

<First Embodiment>

In the first embodiment, a UE operating method for sensing and resource selection when DRX is performed in sidelink is presented.

Specifically, according to FIG. 12, four terminals performing transmission and reception in a sidelink according to an embodiment of the present disclosure are shown. In FIG. 12, UE 1 is a UE to perform sidelink data transmission, that is, PSSCH transmission to UE 2, and UE 2 may be a UE performing sidelink DRX. As mentioned above, in the period in which UE 2 operates in DRX inactive time in the sidelink (that is, UE 2 may not perform decoding of control information and data information in the corresponding time period), UE 1 and UE 2 If sidelink data is transmitted as , UE 2 may not be able to receive it. Therefore, as shown in 1201, when a peer terminal transmitting sidelink data to a terminal performing DRX selects a resource by performing Mode2 sensing, it is necessary to perform resource selection so that the receiving terminal can receive the transmission data. there is. Detailed methods for this refer to the second to third embodiments below. UE 1 may select a resource determined through the resource selection operation considered in step 1201 and transmit the PSCCH/PSSCH 1202 to UE2. Next, in FIG. 12, UE 2 is a terminal that performs sidelink DRX, and sensing operations at inactive time and active time of sidelink DRX may or may not be the same. For the detailed method for the same case, refer to FIGS. 7 to 10 above. Alternatively, sensing may be performed in a non-identical manner, such as in step 1203. This is due to the fact that DRX is an operation to reduce power consumption of the terminal. For details on this, refer to the fourth embodiment below. For reference, in FIG. 12, UE 3 is a UE trying to transmit sidelink data, that is, PSSCH transmission 1205 to UE 4, and UE 4 may be a UE that does not perform sidelink DRX. In this case, UE 2 may perform a sensing operation by receiving and decoding the PSCCH 1204 transmitted by UE 3 regardless of DRX in a sensing period.

<Second Embodiment>

In the second embodiment, as shown in 1201 of FIG. 12, a method of selecting a resource by performing Mode2 sensing by a peer terminal transmitting sidelink data to a terminal performing DRX is presented.

13 is a diagram illustrating a resource selection window during Mode2 operation of a peer terminal transmitting sidelink data to a terminal performing DRX according to an embodiment of the present disclosure.

Referring to FIG. 13, when a peer terminal transmitting sidelink data to a terminal performing DRX determines a resource selection window 1300, a part of the time domain of the resource selection window is the inactive time of the terminal performing DRX (1301 ), and another part of the time domain may correspond to the active time 1302 of the UE performing DRX. As described above, a UE performing DRX may not perform decoding of control information and data information in a corresponding time interval during the DRX inactive time. Therefore, if a peer device transmitting sidelink data to a device performing DRX transmits sidelink data in a time interval corresponding to the DRX inactive time of the device performing DRX, the device performing DRX may not receive the data. can

In the present invention, it is assumed that when a peer device transmits sidelink data to a device performing DRX, it can know DRX configuration information of the corresponding device. Therefore, it is assumed that the peer device can detect the DRX active time or DRX inactive time of the device performing DRX. Specifically, in the case of broadcast or groupcast transmission, DRX configuration can be (pre-)configured when not connected to the base station, and can be set through SIB transmitted by the base station in a cell common way when connected to the base station. Unlike this, in the case of unicast transmission, the TX terminal may instruct the RX terminal to configure DRX or the RX terminal may instruct the TX terminal through PC5-RRC. Therefore, it is assumed that the terminal receives DRX configuration information through the upper layer of the terminal and can grasp its own DRX configuration information and DRX configuration information of other terminals through this.

Therefore, when a peer device transmits sidelink data to a device performing DRX, the following resource selection method can be considered. Note that the following methods are only for illustrative purposes, and the resource selection method in the present invention is not limited to the following methods.

* Method 1: When the terminal selects a set of candidate resources through Mode 2 operation and reports them to the upper layer of the terminal, all resources included in the set are included in the time interval corresponding to the DRX active time of the RX terminal Must be a resource.

* Method 2: When the terminal selects a set of candidate resources through Mode 2 operation and reports them to the upper layer of the terminal, some resources included in the set are included in the time interval corresponding to the DRX active time of the RX terminal and some other resources included in the set may not be included in the time interval corresponding to the DRX active time of the RX terminal.

In the above method, when a set of candidate resources is reported from a physical layer of the terminal to an upper layer of the terminal, the upper layer of the terminal may randomly select a transmission resource from candidate resources included in the set of candidate resources. At this time, not only initial transmission resources but also retransmission resources may be selected. If an initial transmission resource and a retransmission resource are selected, a resource positioned earlier in time among randomly selected resources may become an initial transmission resource and a resource positioned later in time may become a retransmission resource. When method 1 is used, it can be guaranteed that the transmission resource is always selected at the DRX active time of the RX terminal, so that the sidelink data transmitted by the TX terminal is transmitted at the DRX inactive time of the RX terminal. Can be prevented There are advantages to However, when the area corresponding to 1302 in FIG. 13 is small, it may be difficult to secure a sufficient amount of candidate resources included in a set of candidate resources. In general, the amount of candidate resources included in a set of candidate resources must be sufficiently guaranteed to lower the probability of collision with a resource selected by another terminal when the set of candidate resources is reported to an upper layer of a terminal and random selection is performed. can In contrast, when method 2 is used, since it is not guaranteed that transmission resources are always selected at the DRX active time of the RX terminal, sidelink data transmitted by the TX terminal may be transmitted at the DRX inactive time of the RX terminal. There is a downside to being However, even if the area corresponding to 1302 in FIG. 13 is small, candidate resources can be selected even in the area 1301, so there may be no problem in securing a sufficient amount of candidate resources included in the set of candidate resources.

When method 2 described above is used, in order to compensate for the disadvantages of method 2, the initial transmission resource is selected from candidate resources included in the DRX active time among candidate resources included in the set of reported candidate resources. Only randomly selected, and the retransmission resource can be randomly selected from among all candidates included in the set of reported candidate resources. This is due to the fact that initial transmission is more important than retransmission. When method 2 is used, refer to the third embodiment for a detailed method of selecting a set of candidate resources in consideration of DRX.

In addition, the retransmission method in the sidelink can be divided into a HARQ feedback-based retransmission method and a blind retransmission method. The HARQ feedback-based retransmission method is a method in which retransmission is performed when HARQ feedback is performed and NACK is received after initial transmission, and retransmission is not performed otherwise. This method may be possible when PSFCH resources are set in the resource pool to support HARQ feedback and the transmitting terminal activates HARQ feedback through SCI during sidelink transmission. However, since the UE cannot receive HARQ feedback when PSFCH resources are not set in the resource pool or HARQ feedback is not activated, in this case, the UE can perform blind retransmission. Blind retransmission is a method in which, when a UE selects a retransmission resource, repetition is necessarily performed on the corresponding resource. Therefore, when performing blind retransmission, when a peer terminal transmits sidelink data to a terminal performing DRX, it is necessary to ensure that not only initial transmission but also retransmission are transmitted in a time interval corresponding to the DRX active time of the RX terminal. As a condition for using method 2 in the present invention, one or more of the following may be considered. Note that the present invention is not limited only to the following conditions.

* Condition 1: When the UE performs HARQ feedback-based retransmission

* Condition 2: In case of unicast or group cast transmission

* Condition 3: In the case of unicast transmission

* Condition 4: When performing partial sensing or random selection

Condition 2 is due to the fact that HARQ feedback-based retransmission is supported only in unicast or groupcast transmission. Condition 3 is to further limit the environment to which method 2 is applied. Condition 4 may be considered when SL DRX is applied only to partial sensing or random selection rather than full sensing.

14 is a diagram illustrating that method 2 is applied according to the above condition according to an embodiment of the present disclosure.

Referring to FIG. 14 , when at least one of the conditions presented above is satisfied in step 1400, the terminal moves to step 1401 and may apply method 2. In contrast, when 1400 is not satisfied, method 1 may be applied by moving to 1402 . Here, method 1 (1402) may be interpreted as a case in which a subset becomes a whole set in 1401. In other words, Method 2 may include Method 1. In method 2, it may happen that some of the resources included in the set are not included in the time interval corresponding to the DRX active time of the SL DRX of the RX terminal, and all resources are the time corresponding to the DRX active time of the SL DRX of the RX terminal There may be cases where it is included in the interval. Therefore, method 1 may be interpreted as a case of method 2.

<Third Embodiment>

The third embodiment proposes a detailed method of selecting a set of candidate resources in consideration of DRX when Method 1 or Method 2 of the second embodiment is used.

According to the existing Mode 2 resource selection method, the terminal determines a set of candidate resources (S _A ) through the Mode2 procedure in the physical layer and reports it to the upper layer of the terminal, and the upper layer of the terminal randomizes among the resource candidates included in S _A Choose resources wisely. At this time, not only initial transmission resources but also retransmission resources may be selected. If an initial transmission resource and a retransmission resource are selected, a resource positioned earlier in time among randomly selected resources may be an initial transmission resource, and a resource positioned later in time may be a retransmission resource. In the physical layer, when the terminal determines a set of candidate resources (S _A ) through the Mode2 procedure, the corresponding candidate resources may be determined within all candidates (M _total ) in the resource selection window, as shown in FIG. 7 . The process of selecting S _A from M _total is based on the sensing result. Also, according to the Mode2 procedure, resource candidates corresponding to S _A ≥ X·M _total must be selected. Here, X is a factor that determines how many candidate resources to include in S _A , and can be selected from values corresponding to {0.2, 0.35, 0.5}, and can be (pre-)configurated in a resource pool based on priority. Here, X is provided from the upper layer of the terminal to the physical layer, and the Mode2 procedure is performed in the physical layer. If a resource corresponding to the selection result S _A < X·M _total is selected through sensing, the threshold of RSRP (Reference Signal Received Power) can be lowered so that S _A ≥ X·M _total can be guaranteed. This is because, as described above, when the amount of candidate resources included in S _A is sufficiently guaranteed, when the set of candidate resources is reported to the upper layer of the terminal and random selection is performed, the probability of collision with the resource selected by another terminal can be reduced. am.

When DRX is not considered, in full sensing, all slots within the resource selection window [n+T1, n+T2] shown in FIG. 7 can be candidate resources included in M _total , and in partial sensing, periodic resource reservation is In this case, only Y slots within the resource selection window [n+T1, n+T2] can be candidate resources included in M _total , and in case of performing aperiodic resource reservation in partial sensing, the resource selection window [n+T2] T1, n + T2] can be candidate resources included in M _total .

When DRX is taken into account and method 1 is used, all resources included in S _A must be included in the time interval corresponding to the DRX active time of the RX terminal. Therefore, unlike in the past, in full sensing, the resource selection window shown in FIG. 7 Among all slots within [n+T1, n+T2], only the slots included in the time interval corresponding to the DRX active time can be candidate resources included in M _total . In the case of performing periodic resource reservation in partial sensing, resources Only Y slots included in the DRX active time within the selection window [n+T1, n+T2] can be candidate resources included in M _total , and in the case of performing aperiodic resource reservation in partial sensing, the resource selection window [ Only Y' slots included in the DRX active time within [n+T1, n+T2] can be candidate resources included in M _total . Then, it will be possible to select resource candidates corresponding to S _A ≥ X·M _total through the existing Mode2 procedure.

In contrast, when DRX is considered and Method 2 is used, only some resources included in S _A are included in the time interval corresponding to the DRX active time of the RX terminal, and other resources included in the set are included in the RX terminal's DRX active time. It may not be included in the time interval corresponding to DRX active time. When Method 2 is used, when a resource candidate corresponding to S _A ≥ X M _total is selected through the existing Mode2 procedure, the time corresponding to the DRX active time of the RX terminal among the resources included in S _A It may be difficult to secure more than a certain amount of resources included in the section. This is because the time interval corresponding to 1302 may not be sufficiently secured with reference to FIG. 13 and many resource candidates may be excluded from the time interval corresponding to 1302 in the S _A selection process through sensing. Therefore, it is necessary to define a Mode2 procedure to prevent such a problem from occurring. In other words, when the Mode 2 procedure is performed when method 2 is used, it is necessary to ensure that more than a certain amount of resources are secured in the time interval corresponding to the DRX active time of the RX terminal among the resources included in S _A. . For this, the following alternatives may be used. Note that the present invention is not limited to only the alternatives below.

* Alternative 1: When a peer terminal (TX terminal) transmits sidelink data to a terminal performing DRX (RX terminal), the peer terminal (TX terminal) separates S _A into two subsets and performs the Mode2 procedure. . At this time, the first subset is selected based on the time domain corresponding to the DRX active time of the RX terminal within the resource selection window, and the second subset is selected based on the time domain corresponding to the DRX inactive time of the RX terminal within the resource selection window. do.

* Alternative 2: When a peer device (TX device) transmits sidelink data to a device performing DRX (RX device), the peer device (TX device) first selects the DRX active time of the RX device within the resource selection window. Candidate resources included in S _A are selected in the time domain, and only when S _A ≥ X M _total cannot be satisfied by performing the Mode2 procedure in the corresponding area, the DRX inactive time of the RX terminal within the resource selection window In the time domain, candidate resources included in S _A may be additionally selected to satisfy S _A ≥ X·M _total .

More specifically, in the case of alternative 1, the following two detailed operations may be considered.

* Alternative 1-1: All candidates (M _total ) within the resource selection window are candidates M _total (1) in the time domain corresponding to the DRX active time of the RX terminal and candidate M in the time domain corresponding to the DRX inactive time of the RX terminal It can be determined by dividing by _total (2). In this case, M _total = M _total (1) + M _total (2) is satisfied. In the physical layer, the UE selects a resource candidate corresponding to S _A (1) ≥ X M _total (1) and a resource candidate corresponding to S _A (2) ≥ X M _total (2) through two Mode2 procedures. can do. As described above, X is a factor that determines how many candidate resources to include in S _A and is a parameter provided from an upper layer of the UE. Therefore, S _A (1) can be interpreted as a resource candidate selected in the time domain corresponding to DRX active time, and S _A (2) can be interpreted as a resource candidate selected in the time domain corresponding to DRX inactive time. Then, the UE can report S _A =S _A (1) + S _A (2) to the upper layer of the UE. A higher layer of the terminal may randomly select a resource from candidate resources belonging to S _A.

* Alternative 1-2: When all candidates (M _total ) within the resource selection window are determined, in the physical layer, the terminal uses two Mode2 procedures to select resource candidates corresponding to S _A (1) ≥ X Y M _total A resource candidate corresponding to S _A (2) ≥ X·(1-Y)·M _total can be selected. As described above, X is a factor that determines how many candidate resources to include in S _A and is a parameter provided from an upper layer of the UE. In addition, Y is a factor that determines how many candidate resources included in DRX active time are included in S _A , and the value of Y is not limited to a specific value in the present invention. The value of Y can be selected from values between 0 and 1. The value of Y may be a value determined by terminal implementation, a value (pre-)configurated in a resource pool, an independently (pre-)configurated value, or a value configured through PC5-RRC. By receiving the values of X and Y from the upper layer of the UE, the physical layer performs the Mode2 procedure as described above, and S _A =S _A (1) + S _A (2) can be reported to the upper layer of the UE. A higher layer of the terminal may randomly select a resource from candidate resources belonging to S _A.

Unlike alternative 1, in the case of alternative 2, the operation of the corresponding terminal will be described in detail below. When all candidates (M _total ) within the resource selection window are determined, in the physical layer, the terminal first selects candidate resources included in S _A in the time domain corresponding to the DRX active time of the RX terminal within the resource selection window. However, when the time domain corresponding to 1302 in FIG. 13 is not sufficiently secured, a case may occur in which S _A ≥ X·M _total cannot be satisfied by performing the Mode2 procedure. As mentioned above, when a resource corresponding to the selection result S _A < X M _total is selected through sensing, the UE lowers the RSRP threshold so that the resource candidate corresponding to S _A ≥ X M _total is guaranteed. there is. However, note that when there are few candidate resources belonging to area 1302, there may occur a case where S _A ≥ X·M _total cannot be satisfied no matter how low the threshold of RSRP is. Therefore, alternative 2 is a method of additionally selecting candidate resources included in S _A in the time domain corresponding to the DRX inactive time of the RX terminal within the resource selection window only in this case to satisfy S _A ≥ X·M _total .

<Fourth Embodiment>

In the fourth embodiment, as shown in 1203 of FIG. 12, a detailed operation for the case where the sensing operation at the inactive time and the active time of the sidelink DRX of the terminal performing sidelink DRX may not be the same is proposed. . This is due to the fact that DRX is an operation to reduce power consumption of the terminal.

The operation of sensing by a general terminal has been described through FIG. 7 (full sensing), FIG. 8 (partial sensing for periodic transmission), and FIG. 9 (partial sensing for aperiodic transmission). If the terminal performs sidelink DRX and operates in DRX inactive time (that is, the terminal may not perform decoding of control information and data information in the corresponding time interval), the following sensing operation may be considered. can

* Full sensing is not performed. In other words, partial sensing is performed.

* The value of k described with reference to FIGS. 8 and 9 is always assumed to be 1. Even if (pre-)configurated as K=2, sensing is performed only in slots corresponding to k=1.

* CPS is not performed. In other words, only Periodic Based Partial Sensing (PBPS) is performed.

<Fifth Embodiment>

As described with reference to FIG. 10, the fifth embodiment proposes an operation of a UE performing Mode 2 through cooperation between UEs in a sidelink. In the conventional Mode2, a transmitting terminal intending to transmit sidelink data performs resource allocation for sidelink data transmission through direct sensing and resource selection operations. However, in the advanced Mode 2 scheme, a terminal other than the transmitting terminal may provide resource allocation related information to the transmitting terminal. Here, the provision of information related to resource allocation to the transmitting terminal by another terminal other than the transmitting terminal may be referred to as cooperation between terminals. In this case, the transmitting terminal may perform Mode 2 resource selection using both the sensing and resource selection operations of the transmitting terminal and inter-terminal cooperation information provided by other terminals, or by using only inter-terminal cooperation information provided by other terminals. Note that Mode 2 resource selection may be performed. In this embodiment, UE-A transmits suitable (preferred) or unsuitable (non-preferred) time-frequency resource allocation set information to UE-B according to UE-to-UE cooperation method 1 described in FIG. 10 . When provided, a method for instructing the corresponding information and a terminal operation are proposed. In the present invention, cooperation information between terminals may be named RSAI (Resource Selection Assistance Information).

First, according to the method presented in this embodiment, UE-A transmits set information of suitable (preferred) or unsuitable (non-preferred) time-frequency resource allocation to UE-B according to UE-to-UE cooperation method 1. In the case of providing, the following two transmission methods can be considered.

* Transmission method 1: When UE-B requests UE-A to cooperate with UEs, UE-A provides UE-B with UE-B cooperation information.

* Transmission method 2: When certain specific conditions are satisfied, UE-A provides inter-UE cooperation information to UE-B.

In the case of transmission method 2, the specific condition may be a periodically set time. Then, UE-A may provide inter-UE cooperation information to UE-B at a configured time point. However, specific conditions are not limited thereto in the present invention. Also, note that both transmission method 1 and transmission method 2 may be considered in the sidelink, or only one method may be considered.

In this embodiment, attention is paid to the transmission method 1. In transmission method 1, the following methods may be considered as a method for UE-B to request cooperation between UEs to UE-A. Note that the present invention is not limited to the following method.

* Transmission method 1-1-1: requesting cooperation information between terminals through MAC CE

* Transmission method 1-1-2: requesting cooperation information between devices through 2 ^nd SCI

* Transmission method 1-1-3: request for cooperation information between terminals through PSFCH

When ^2nd SCI is used in the above method, it can be performed through a newly defined ^2nd SCI format in the sidelink. In this embodiment, the corresponding 2 ^nd SCI format is named 2 ^nd SCI format X. 2 ^nd SCI format X may include information included in Table 1 as well as RSAI request, which is information requesting cooperation between terminals. That is, for cooperation between terminals, UE-B may provide information provided in Table 1 to UE-A when requesting cooperation between terminals through 2 ^nd SCI format X.

Also, as a combination of the above methods, a method in which UE-B requests cooperation between UEs to UE-A may be considered. For example, referring to Table 1, since RSAI request, which is information requesting cooperation between terminals, can be indicated as 1-bit information, it can be indicated through the PSFCH according to the transmission method 1-1-3. Unlike this, other information shown in Table 1 is difficult to transmit through PSFCH, so a method of transmitting through 2 ^nd SCI according to transmission method 1-1-2 may be considered.

In contrast, in transmission method 1, the following two methods can be considered as a method of providing UE-A cooperation information from UE-A to UE-B. Note that the present invention is not limited to the following method.

* Transmission method 1-2-1: Signaling cooperation information between terminals through MAC CE

* Transmission method 1-2-2: When the amount of cooperation information between terminals exceeds a specific threshold, cooperation information between terminals is signaled through MAC CE, and otherwise, cooperation information between terminals is signaled through 2 ^nd SCI.

When ^2nd SCI is used in the above method, it can be performed through a newly defined ^2nd SCI format in the sidelink. This may be determined as the same ^2nd SCI format X as the ^2nd SCI format described in the transmission method 1-1-2, or may be defined as another new ^2nd SCI format different from the ^2nd SCI format X. If it is determined that the ^2nd SCI format X is the same as the ^2nd SCI format described in transmission method 1-1-2, it may be a method considering the type of limited ^2nd SCI format. Specifically, since the bit indicating the type of the ^2nd SCI format with the current 1 ^st SCI is 2 bits, there is an advantage in that space can be left for another ^2nd SCI format in the future when the corresponding method is used. Specifically, when the 2 ^nd SCI format in the transmission method 1-2-2 is determined to be the same 2 ^nd SCI format X as the 2 ^nd SCI format in the transmission method 1-1-2, the 2 ^nd SCI format X is a fixed payload It is determined by the size and the information used may vary depending on whether it is used in the transmission method 1-1-2 or the transmission method 1-2-2. The ^2nd SCI format for signaling cooperation information between terminals according to the first transmission method 1-2-2 may include the following bit fields in addition to the bit fields shown in Table 1.

In Table 2, Identifier for SCI Format, as described above, indicates whether the corresponding information in one band is information requesting cooperation between terminals according to transmission method 1-1-2 or cooperation information between terminals according to transmission method 1-2-2. It may be a field that distinguishes whether information is provided. Also, in Table 2, RSAI feedback is a field corresponding to cooperation information between terminals. In the present invention, the amount of corresponding information is not limited to a specific value.

According to transmission methods 1-1-1, 1-1-2, 1-1-3 and transmission methods 1-2-1 and 1-2-2 presented above, sidelink terminals request cooperation between terminals and between terminals. Note that in the case of providing cooperation information, the corresponding information can be indicated in different ways. For example, when transmission method 1 is used in the sidelink transmission method, when transmission method 1-1-2 and transmission method 1-2-1 are considered, information for cooperation between terminals as shown in FIG. 15 Depending on this, the terminal may indicate the corresponding information using another method. For the transmission method, refer to the above description.

<Sixth Embodiment>

As described with reference to FIG. 10, the sixth embodiment proposes an operation of a UE performing Mode 2 through cooperation between UEs in a sidelink. In FIG. 10, according to UE-to-UE cooperation method 1, UE-A may provide UE-B with set information on time-frequency resource allocation that is suitable (preferred) or unsuitable (non-preferred) for transmission to UE-B. Also, as described in the fifth embodiment, transmission method 1 below may be considered.

* Transmission method 1: When UE-B requests UE-A to cooperate with UEs, UE-A provides UE-B with UE-B cooperation information.

In this embodiment, a condition for requesting inter-UE cooperation information from UE-A to UE-B in transmission method 1 is proposed. Specifically, the options shown in Table 3 may be considered.

Note that the present invention is not limited to the options presented above. Specifically, when one of the options other than Option 9 is a necessary and sufficient condition for requesting inter-device cooperation information from UE-A to UE-B, the conditions for requesting inter-device cooperation may be very limited. Accordingly, a condition for requesting UE-to-UE cooperation information from UE-A to UE-B may be determined by a combination of the options presented above. For example, Option 1 may be a necessary condition for UE-A to request inter-UE cooperation information from UE-B. Also, other options may be determined by terminal implementation.

<Seventh Embodiment>

The seventh embodiment proposes a detailed method of selecting a set of candidate resources in consideration of DRX when Method 1 or Method 2 of the second embodiment is used. In addition, the seventh embodiment proposes a method using the methods proposed in the third embodiment and an additional method for selecting a set of candidate resources in consideration of DRX.

First, Method 1 or Method 2 in the second embodiment is as follows. Note that the present invention is not limited to only the following methods.

* Method 1: When the terminal selects a set of candidate resources through Mode 2 operation and reports them to the upper layer of the terminal, all resources included in the set are included in the time interval corresponding to the DRX active time of the RX terminal Must be a resource.

* Method 2: When the terminal selects a set of candidate resources through Mode 2 operation and reports them to the upper layer of the terminal, some resources included in the set are included in the time interval corresponding to the DRX active time of the RX terminal and some other resources included in the set may not be included in the time interval corresponding to the DRX active time of the RX terminal.

In sidelink Mode 2 transmission, the TX terminal selects a transmission resource for periodic transmission and uses a non-zero reservation interval (or periodicity) There is a method of periodically reserving transmission resources by indicating SCI (1 ^st SCI). Specifically, may have various values such as 0, 1:99, 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000. In contrast, the TX terminal selects transmission resources for aperiodic transmission and through SCI (1 ^st SCI) There is a method of performing aperiodic transmission by instructing to 0.

DRX in the sidelink may be operated by setting DRX-related parameters as shown in FIG. 11 in consideration of periodic transmission of a TX terminal. Therefore, the TX terminal selects a transmission resource for periodic transmission and performs periodic transmission ( ), a slot for which the TX terminal periodically reserves transmission resources through SCI (1 ^st SCI) may be regarded as DRX active time by the RX terminal. According to this method, even if a candidate resource selected from the set of candidate resources reported to the upper layer of the terminal through sensing in the physical layer is included in the time interval corresponding to the DRX inactive time, if the corresponding resource is selected and transmitted, the periodically reserved resource Method 1 or Method 2 of the second embodiment may not be necessary because these are regarded as DRX active time by the RX terminal and there is no problem for the RX terminal to receive data transmitted by the TX terminal. However, the TX terminal still performs aperiodic transmission ( ), method 1 or method 2 of the second embodiment presented above needs to be considered.

18 is a diagram illustrating a terminal operation according to whether a TX terminal performs periodic transmission according to an embodiment of the present disclosure.

18 is a TX terminal selects a transmission resource for periodic transmission and performs periodic transmission according to an embodiment of the present disclosure ( ), the slot for which the TX terminal periodically reserves transmission resources through SCI (1 ^st SCI) may be applied to the case where it is regarded as DRX active time by the RX terminal.

Referring to FIG. 18, in 1800, a TX terminal selects a transmission resource for periodic transmission and performs periodic transmission ( ), the terminal may move to 1801 and report the candidate resource selected using the existing Mode2 method to the upper level of the terminal. The existing Mode 2 method may be a method of selecting candidate resources regardless of sidelink DRX configuration. According to this method, in the process of selecting candidate resources, the terminal may not adjust the candidate resources to be included in the DRX active time. In contrast, when 1800 is not satisfied, in other words, the TX terminal performs aperiodic transmission ( ), go to step 1802 and report the selected candidate resource to the upper terminal using the modified Mode2 method. Unlike the existing Mode 2 method, the modified Mode 2 method selects candidate resources in consideration of sidelink DRX configuration. For example, Method 1 or Method 2 of the second embodiment may be applied.

In the following embodiment, a more specific terminal operation corresponding to 1802 in FIG. 18 is proposed. However, note that the present invention is not limited to the following alternatives. A combination of the alternatives below may also be used. In addition, the operation of the terminal used among the alternatives below may be (pre-)configurated.

First, as a first alternative, before selecting candidate resources using the sensing result, limit that at least N candidate resources (N slots) among resource selection candidate resources within the resource selection window [n+T1, n+T2] are in DRX active time way to do it For details on the resource selection window, refer to FIGS. 7 to 9 . Specifically, in full sensing, as shown in FIG. 7, N out of M _total (the total number of candidate resources before selecting candidate resources using the sensing result) candidate resources within the resource selection window [n+T1, n+T2] Candidate resources (N slots) may be restricted to be in DRX active time. As shown in FIG. 8, when performing periodic resource reservation in partial sensing ( ) In Y slots within the resource selection window [n+T1, n+T2], N candidate resources (N slots) may be restricted to be in DRX active time. As shown in FIG. 9, when performing aperiodic resource reservation in partial sensing ( ) N candidate resources (N slots) in Y' slots within the resource selection window [n+T1, n+T2] may be restricted to be in DRX active time. Note that in partial sensing, Y or Y' may be M _total (the total number of candidate resources before candidate resources are selected using a sensing result). In the above alternative, the value of N can be (pre-)configurated, and the value that can be set as the value of N in the present invention does not limit the range to a specific value. Also, the N candidate resources may be limited to resources located earlier in time. Also, N candidate resources may be M _total in full sensing or N=Y or N=Y' in partial sensing.

As a second alternative, when a set of candidate resources ( _SA ) is determined by using the sensing result in the physical layer and reported to the upper layer of the UE, at least K candidate resources (K slots) among the candidate resources included in S _A are DRX It is a way to limit it to be in active time. Here, all candidate resources of S _A may be in DRX active time. Specifically, candidate resources corresponding to X·N _total may be selected. Here, N _total represents the number of all candidate resources corresponding to DRX active time among candidate resources included in S _A. And X is a factor indicating how many candidate resources to select from among N _total , and is a parameter provided from an upper layer of the terminal. For example, X may be selected from values corresponding to {0.2, 0.35, 0.5} and may be (pre-)configurated in a resource pool based on priority. If, through sensing, as a result of the selection, if fewer resources than X N _total are selected, the RSRP (Reference Signal Received Power) threshold may be lowered so that X N _total is selected. This is because the probability of collision with a resource selected by another terminal can be reduced when a set of candidate resources is reported to an upper layer of a terminal and random selection is performed only when the amount of candidate resources is sufficiently guaranteed. In the second alternative, selecting and reporting resource candidates corresponding to X·N _total may be interpreted as a separate operation from the operation of determining S _A through the existing Mode 2 procedure and reporting it to the upper layer of the terminal.

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. 16 and 17, respectively. In the above embodiments, a method for a terminal to perform multi-antenna transmission and reception in a sidelink is shown.

Specifically, FIG. 16 is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention. As shown in FIG. 16, the terminal of the present invention may include a terminal receiving unit 1600, a terminal transmitting unit 1604, and a terminal processing unit 1602. The terminal receiving unit 1600 and the terminal transmitting unit 1604 may be collectively referred to as a transmitting/receiving unit in an embodiment of the present invention. The transmitting/receiving unit may transmit/receive signals with the base station. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying 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 1602, and transmit the signal output from the terminal processing unit 1602 through a wireless channel. The terminal processing unit 1602 can control a series of processes so that the terminal can operate according to the above-described embodiment of the present invention.

17 is a block diagram showing the internal structure of a base station according to an embodiment of the present invention. As shown in FIG. 17, the base station of the present invention may include a base station receiving unit 1701, a base station transmitting unit 1705, and a base station processing unit 1703. The base station receiving unit 1701 and the base station transmitting unit 1705 may collectively be referred to as transceivers in an embodiment of the present invention. The transmission/reception unit may transmit/receive signals with the terminal. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying 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 1703, and transmit the signal output from the terminal processor 1703 through a radio channel. The base station processing unit 1703 can control a series of processes so that the base station can operate according to the above-described embodiment of the present invention.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are only presented as specific examples to easily explain the technical 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.

Claims (1)

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