KR20200112652A - Apparatus and method for enabling harq feedback transmission in terminal direct communication system - Google Patents

Abstract

The present invention relates to a 5th generation (5G) or pre-5G communication system for supporting a higher data transmission rate than that of the 4th generation (4G) communication system such as the long term evolution (LTE). The present invention is applicable to intelligence services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, security and safety-related services, etc. In addition, the method of operating a terminal in a wireless communication system may comprise the steps of: determining the service information required by a V2X application and determining the V2X transmission mode; determining the QoS information of the service required by the V2X application; acquiring side link wireless bearer configuration information corresponding to the QoS information; and performing the V2X packing transmission/reception of a direct communication method by using the acquired side link wireless bearer configuration information. The method and the apparatus for supporting an HARQ feedback transmission in a terminal direct communication system are able to achieve a high reliability and a low delay requirement value.

Description

Method and apparatus for supporting HARQ feedback transmission in the terminal direct communication system {APPARATUS AND METHOD FOR ENABLING HARQ FEEDBACK TRANSMISSION IN TERMINAL DIRECT COMMUNICATION SYSTEM}

The present disclosure generally relates to a wireless communication system, and more particularly, to an apparatus and method for supporting feedback signaling for data transmission of a direct communication bearer in a wireless communication system.

Efforts have been made to develop an improved 5G (5th generation) communication system or a pre-5G communication system in order to meet the increasing demand for wireless data traffic after the commercialization of 4G (4th generation) communication systems. For this reason, the 5G communication system or the pre-5G communication system is called a Beyond 4G Network communication system or a Long Term Evolution (LTE) system (Post LTE) system.

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

In addition, in order to improve the network of the system, in 5G communication system, advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation And other technologies are being developed.

In addition, in the 5G system, the advanced coding modulation (Advanced Coding Modulation, ACM) method of FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation) and SWSC (Sliding Window Superposition Coding), and advanced access technology, FBMC (Filter Bank Multi Carrier) ), NOMA (Non Orthogonal Multiple Access), and SCMA (Sparse Code Multiple Access) are being developed.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans create and consume information, to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between objects, 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 value in human life by collecting and analyzing data generated from connected objects can be provided. IoT is the field of smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliance, advanced medical service, etc. through the convergence and combination of existing IT (information technology) technology and various industries. Can be applied to.

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

In 5G systems, air interface schemes for providing services having various quality of service (QoS) requirements are being discussed. For example, a direct communication method for a vehicle to everything (V2X) terminal has been proposed. Furthermore, various discussions are underway to reduce communication time, increase reliability, and support direct communication between terminals more efficiently.

Based on the above discussion, the present disclosure provides a method of performing direct communication between terminals in a vehicle communication system to support vehicle communication services and data transmission that achieve high reliability and low latency requirements. It provides an apparatus and method for

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

According to various embodiments of the present disclosure, in a method of operating a terminal in a wireless communication system, the terminal determines a V2X service requiring sidelink direct communication, determines quality of service (QoS) information required by the service, and the service is It includes the process of acquiring required reliability requirements or latency requirements information. It includes the process of controlling radio parameter setting for sidelink V2X so that feedback signaling for a transport packet can be transmitted so as to satisfy the reliability QoS requirements of the vehicle to everything communication (V2X) service using sidelink direct communication. It includes the process of controlling the radio parameter setting for the sidelink V2X so that feedback signaling for the transport packet is not transmitted to satisfy the latency QoS requirements of the vehicle to everything communication (V2X) service using sidelink direct communication. In the process of acquiring radio parameter setting information for determining whether a terminal transmitting and receiving a direct communication-based V2X service transmits feedback signaling, the process of transmitting QoS information of the service to the base station and determining whether to transmit the feedback signaling for the radio bearer of the corresponding service The process of acquiring the parameter setting information for the terminal and the process of obtaining the terminal by providing the parameter setting information for determining whether the base station transmits the feedback signaling of the radio bearer corresponding to the QoS information as a system parameter, and the QoS information preset in the terminal And a process of obtaining, by the terminal, parameter setting information for determining whether to transmit feedback signaling of a radio bearer corresponding to.

According to various embodiments of the present disclosure, in a wireless communication system, a terminal device includes a transceiver and at least one processor functionally coupled to the transceiver. The at least one processor, when it is determined that the terminal is in the coverage of the base station, the terminal determines the QoS information requested by the V2X service, and a parameter for determining whether to transmit the feedback signaling of the radio bearer corresponding to the QoS information to the base station Controls to perform the assigned operation by requesting setting information. The at least one process, when it is determined that the terminal is not in the coverage of the base station, determines the QoS information required by the V2X service, and parameter setting information for determining whether to transmit the feedback signaling of the radio bearer corresponding to the preset QoS information. It controls to perform an operation to obtain.

According to various embodiments of the present disclosure, a method of operating a terminal in a wireless communication system is a process of determining service information requested by a V2X application and determining QoS information of a service requested by the V2X application, corresponding to the QoS information. Including the process of acquiring parameter setting information for determining whether to transmit the feedback signaling of the sidelink radio bearer and performing V2X packet transmission and reception of the direct communication method using the obtained sidelink radio bearer parameter setting information can do.

According to various embodiments of the present disclosure, in a wireless communication system, a terminal device includes a transmission/reception unit for transmitting/receiving data and at least one processor functionally coupled to the transmission/reception unit, and the at least one processor is required by the V2X application. Determine service information, determine QoS information of a service requested by the V2X application, obtain parameter setting information for determining whether to transmit feedback signaling of a sidelink radio bearer corresponding to the QoS information, and obtain the obtained side Direct communication V2X packet transmission and reception can be performed using link radio bearer parameter setting information.

An apparatus and method according to various embodiments of the present disclosure provides a method for supporting a vehicle communication service that requires various quality of service (QoS) by using direct communication between terminals in a vehicle communication system, thereby providing reliability in vehicle communication. And low latency requirements.

The effects obtainable in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the technical field to which the present disclosure belongs from the following description. will be.

1 illustrates a wireless communication system according to various embodiments of the present disclosure.
2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure.
3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure.
4A is a diagram illustrating a configuration of a communication unit in a wireless communication system according to various embodiments of the present disclosure.
4B illustrates an example in which an independent antenna array for each transmission path is used in an analog beamforming unit of a communication unit in a wireless communication system according to various embodiments of the present disclosure.
4C illustrates an example in which transmission paths share one antenna array in an analog beamforming unit of a communication unit in a wireless communication system according to various embodiments of the present disclosure.
5 illustrates a situation in which direct communication between terminals is performed using a sidelink radio access technology (RAT) according to various embodiments of the present disclosure.
6A illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_CONNECTED state according to various embodiments of the present disclosure.
6B illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_CONNECTED state according to various embodiments of the present disclosure.
7A illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_IDLE state or a terminal in an RRC_INACTIVE state according to various embodiments of the present disclosure.
7B illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_IDLE state or a terminal in an RRC_INACTIVE state according to various embodiments of the present disclosure.
7C illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_IDLE state or a terminal in an RRC_INACTIVE state according to various embodiments of the present disclosure.
7D illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_IDLE state or a terminal in an RRC_INACTIVE state according to various embodiments of the present disclosure.
FIG. 7E illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_IDLE state or a terminal in an RRC_INACTIVE state according to various embodiments of the present disclosure.
8A illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an OUT-OF-COVERAGE state according to various embodiments of the present disclosure.
8B illustrates a signaling procedure for setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an OUT-OF-COVERAGE state according to various embodiments of the present disclosure.
9A illustrates a signaling procedure for setting a parameter for determining whether feedback signaling is transmitted between terminals performing direct communication-based V2X packet transmission and reception according to various embodiments of the present disclosure.
9B illustrates a signaling procedure for setting a parameter for determining whether feedback signaling is transmitted between terminals performing direct communication-based V2X packet transmission and reception according to various embodiments of the present disclosure.
9C illustrates a signaling procedure for setting parameters for determining whether feedback signaling is transmitted between terminals performing direct communication-based V2X packet transmission and reception according to various embodiments of the present disclosure.
10A illustrates the operation of a transmitting terminal according to various embodiments of the present disclosure.
10B is a diagram illustrating an operation of a receiving terminal according to various embodiments of the present disclosure.
11A shows a signaling procedure between a terminal and a base station for processing a feedback signaling transmission resource according to various embodiments of the present disclosure.
11B illustrates a signaling procedure between a terminal and a base station for processing a feedback signaling transmission resource according to various embodiments of the present disclosure.
11C illustrates a signaling procedure between a terminal and a base station for processing a feedback signaling transmission resource according to various embodiments of the present disclosure.
12 is a diagram illustrating a signal flow through which a terminal transmits HARQ feedback assistance information to a base station according to various embodiments of the present disclosure.
13 illustrates an operation in which a terminal selects a sidelink resource by itself according to whether HARQ feedback is performed according to various embodiments of the present disclosure.
14 illustrates an operation of a terminal according to various embodiments of the present disclosure.

Terms used in the present disclosure are used only to describe a specific embodiment, and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the technical field described in the present disclosure. Among the terms used in the present disclosure, terms defined in a general dictionary may be interpreted as having the same or similar meaning as the meaning in the context of the related technology, and unless explicitly defined in the present disclosure, an ideal or excessively formal meaning Is not interpreted as. In some cases, even terms defined in the present disclosure cannot be interpreted to exclude embodiments of the present disclosure.

In various embodiments of the present disclosure described below, a hardware approach is described as an example. However, since various embodiments of the present disclosure include technology using both hardware and software, various embodiments of the present disclosure do not exclude a software-based approach.

Hereinafter, the present disclosure relates to an apparatus and method for obtaining a configuration parameter for determining a feedback signaling transmission of a sidelink radio bearer corresponding to a quality of service (QoS) requirement of a vehicle to everything communication (V2X) service in a wireless communication system. will be. Feedback signaling may include HARQ feedback, for example. Specifically, the present disclosure provides QoS required for various V2X services based on a method of obtaining configuration parameters for determining feedback signaling transmission of a sidelink radio bearer for direct sidelink communication between V2X (vehicle to everything) terminals in a wireless communication system. Describe the skills that can satisfy the level.

In the following description, a term referring to a signal, a term referring to a channel, a term referring to control information, a term referring to network entities, a term referring to a component of a device, etc. are for convenience of description. It is illustrated. Accordingly, the present disclosure is not limited to terms to be described later, and other terms having an equivalent technical meaning may be used.

In addition, the present disclosure describes various embodiments using terms used in some communication standards (eg, 3rd Generation Partnership Project (3GPP)), but this is only an example for description. Various embodiments of the present disclosure may be easily modified and applied to other communication systems.

1 illustrates a wireless communication system according to various embodiments of the present disclosure. 1 illustrates a base station 110, a terminal 120, and a terminal 130 as some of nodes using a radio channel in a wireless communication system. 1 shows only one base station, but another base station that is the same as or similar to the base station 110 may be further included. FIG. 1 shows only two terminals, but other terminals identical or similar to terminal 120 and terminal 130 may be further included.

The base station 110 is a network infrastructure that provides wireless access to the terminals 120 and 130. The base station 110 has a coverage defined as a certain geographic area based on a distance at which signals can be transmitted. In addition to the base station, the base station 110 is'access point (AP)','eNodeB, eNB', '5G node', '5G node ratio (gNodeB, gNB)' ,'Wireless point','transmission/reception point (TRP)', or another term having an equivalent technical meaning.

Each of the terminal 120 and terminal 130 is a device used by a user and performs communication with the base station 110 through a radio channel. In some cases, at least one of the terminal 120 and the terminal 130 may be operated without user involvement. That is, at least one of the terminal 120 and the terminal 130 is a device that performs machine type communication (MTC) and may not be carried by a user. Each of the terminal 120 and terminal 130 is'user equipment (UE)','mobile station','subscriber station','remote terminal', and'other than terminal'. It may be referred to as'wireless terminal','user device', or another term having an equivalent technical meaning.

The base station 110, the terminal 120, and the terminal 130 may transmit and receive radio signals in a sub 6 GHz band and a millimeter wave (mmWave) band (eg, 28 GHz, 30 GHz, 38 GHz, 60 GHz). In this case, in order to improve the channel gain, the base station 110, the terminal 120, and the terminal 130 may perform beamforming. Here, beamforming may include transmission beamforming and reception beamforming. That is, the base station 110, the terminal 120, and the terminal 130 may give directivity to a transmitted signal or a received signal. To this end, the base station 110 and the terminals 120 and 130 may select serving beams 112, 113, 121, and 131 through a beam search or beam management procedure. After the serving beams 112, 113, 121, and 131 are selected, subsequent communication may be performed through a resource having a quasi-co-located (QCL) relationship with a resource transmitting the serving beams 112, 113, 121, and 131.

If large-scale characteristics of the channel carrying the symbol on the first antenna port can be inferred from the channel carrying the symbol on the second antenna port, the first antenna port and the second antenna port are in a QCL relationship. Can be evaluated. For example, a wide range of characteristics include delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial receiver parameter. It may include at least one of.

2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 2 can be understood as the configuration of the base station 110. Terms such as'... unit' and'... group' used below refer to units that process at least one function or operation, which can be implemented by hardware or software, or a combination of hardware and software. have.

Referring to FIG. 2, the base station includes a wireless communication unit 210, a backhaul communication unit 220, a storage unit 230, and a control unit 240.

The wireless communication unit 210 performs functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit 210 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when transmitting data, the wireless communication unit 210 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the wireless communication unit 210 restores the received bit stream through demodulation and decoding of the baseband signal.

In addition, the wireless communication unit 210 up-converts the baseband signal into a radio frequency (RF) band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit 210 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), and the like. In addition, the wireless communication unit 210 may include a plurality of transmission/reception paths. Furthermore, the wireless communication unit 210 may include at least one antenna array composed of a plurality of antenna elements.

In terms of hardware, the wireless communication unit 210 may be composed of a digital unit and an analog unit, and the analog unit is composed of a plurality of sub-units according to operating power and operating frequency. Can be. The digital unit may be implemented with at least one processor (eg, a digital signal processor (DSP)).

The wireless communication unit 210 transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit 210 may be referred to as a'transmitter', a'receiver', or a'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel are used in a sense including the processing as described above is performed by the wireless communication unit 210.

The backhaul communication unit 220 provides an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 220 converts a bit stream transmitted from the base station to another node, for example, another access node, another base station, an upper node, a core network, etc., into a physical signal, and converts a physical signal received from another node into a bit stream. Convert to

The storage unit 230 stores data such as a basic program, an application program, and setting information for the operation of the base station. The storage unit 230 may be formed of a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. Then, the storage unit 230 provides the stored data according to the request of the control unit 240.

The controller 240 controls overall operations of the base station. For example, the controller 240 transmits and receives signals through the wireless communication unit 210 or through the backhaul communication unit 220. In addition, the control unit 240 writes and reads data in the storage unit 230. In addition, the control unit 240 may perform functions of a protocol stack required by a communication standard. According to another implementation example, the protocol stack may be included in the wireless communication unit 210. To this end, the controller 240 may include at least one processor.

According to various embodiments, the controller 240 may transmit radio resource control (RRC) configuration information to the terminal 110. The controller 240 may transmit sidelink configuration information to the terminal 110. For example, the controller 240 may control the base station to perform operations according to various embodiments described below.

3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 3 may be understood as a configuration of terminal 120 or terminal 130. Terms such as'... unit' and'... group' used below refer to units that process at least one function or operation, which can be implemented by hardware or software, or a combination of hardware and software. have.

Referring to FIG. 3, the terminal includes a communication unit 310, a storage unit 320, and a control unit 330.

The communication unit 310 performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit 310 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when transmitting data, the communication unit 310 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the communication unit 310 restores the received bit stream through demodulation and decoding of the baseband signal. In addition, the communication unit 310 up-converts the baseband signal to an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the communication unit 310 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

In addition, the communication unit 310 may include a plurality of transmission/reception paths. Furthermore, the communication unit 310 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit 310 may be composed of a digital circuit and an analog circuit (eg, a radio frequency integrated circuit (RFIC)). Here, the digital circuit and the analog circuit may be implemented in one package. In addition, the communication unit 310 may include a plurality of RF chains. Furthermore, the communication unit 310 may perform beamforming.

In addition, the communication unit 310 may include different communication modules to process signals of different frequency bands. Furthermore, the communication unit 310 may include a plurality of communication modules to support a plurality of different wireless access technologies. For example, different wireless access technologies include Bluetooth low energy (BLE), Wireless Fidelity (Wi-Fi), WiFi Gigabyte (WiGig), and cellular networks (e.g., Long Term Evolution (LTE)). In addition, different frequency bands may include a super high frequency (SHF) (eg 2.5GHz, 3.5 GHz, 5GHz) band, and a millimeter wave (eg 60GHz) band.

The communication unit 310 transmits and receives signals as described above. Accordingly, all or part of the communication unit 310 may be referred to as a'transmitting unit', a'receiving unit', or a'transmitting/receiving unit'. In addition, in the following description, transmission and reception performed through a wireless channel are used in a sense including the processing as described above by the communication unit 310.

The storage unit 320 stores data such as a basic program, an application program, and setting information for the operation of the terminal. The storage unit 320 may include a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. Further, the storage unit 320 provides stored data according to the request of the control unit 330.

The controller 330 controls overall operations of the terminal. For example, the control unit 330 transmits and receives signals through the communication unit 310. Also, the control unit 330 writes and reads data in the storage unit 320. In addition, the control unit 330 may perform functions of a protocol stack required by a communication standard. To this end, the controller 330 may include at least one processor or a micro processor, or may be a part of a processor. In addition, a part of the communication unit 310 and the control unit 330 may be referred to as a communication processor (CP).

According to various embodiments, when the terminal 120 performs sidelink direct communication with another terminal, the controller 330 determines the service information required by the V2X application and determines the QoS information of the V2X service, and the QoS V2X of the direct communication method using the process of acquiring the configuration parameters necessary to determine the feedback signaling transmission of the sidelink radio bearer corresponding to the information and the configuration information necessary to determine the feedback signaling transmission of the obtained sidelink radio bearer. A process of transmitting and receiving packets can be performed. For example, the controller 330 may control the terminal to perform operations according to various embodiments to be described later.

4A to 4C illustrate a configuration of a communication unit in a wireless communication system according to various embodiments of the present disclosure. 4A to 4C show examples of detailed configurations of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3. Specifically, FIGS. 4A to 4C are parts of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3, and illustrate components for performing beamforming.

Referring to FIG. 4A, the wireless communication unit 210 or the communication unit 310 includes an encoding and modulating unit 402, a digital beamforming unit 404, a plurality of transmission paths 406-1 to 406-N, and an analog beamforming unit 408.

The encoding and modulating unit 402 performs channel encoding. For channel encoding, at least one of a low density parity check (LDPC) code, a convolution code, and a polar code may be used. The encoding and modulating unit 402 generates modulation symbols by performing constellation mapping.

The digital beamforming unit 404 performs beamforming on a digital signal (eg, modulation symbols). To this end, the digital beamforming unit 404 multiplies the modulation symbols by beamforming weights. Here, the beamforming weights are used to change the size and phase of a signal, and may be referred to as a'precoding matrix', a'precoder', and the like. The digital beamforming unit 404 outputs digitally beamformed modulation symbols through a plurality of transmission paths 406-1 to 406-N. In this case, according to a multiple input multiple output (MIMO) transmission scheme, modulation symbols may be multiplexed or the same modulation symbols may be provided through a plurality of transmission paths 406-1 to 406-N.

The plurality of transmission paths 406-1 to 406-N convert digital beamformed digital signals into analog signals. To this end, each of the plurality of transmission paths 406-1 to 406-N may include an inverse fast fourier transform (IFFT) operation unit, a cyclic prefix (CP) insertion unit, a DAC, and an up-conversion unit. The CP insertion unit is for an orthogonal frequency division multiplexing (OFDM) scheme, and may be excluded when another physical layer scheme (eg, filter bank multi-carrier (FBMC)) is applied. That is, a plurality of transmission paths 406-1 to 406-N provide an independent signal processing process for a plurality of streams generated through digital beamforming. However, depending on the implementation method, some of the components of the plurality of transmission paths 406-1 to 406-N may be used in common.

The analog beamforming unit 408 performs beamforming on an analog signal. To this end, the digital beamforming unit 404 multiplies the analog signals by beamforming weights. Here, the beamforming weights are used to change the magnitude and phase of the signal. Specifically, the analog beamforming unit 408 may be configured as shown in FIG. 4B or 4C according to a plurality of transmission paths 406-1 to 406-N and a connection structure between antennas.

Referring to FIG. 4B, signals input to the analog beamforming unit 408 are transmitted through antennas through phase/magnitude conversion and amplification operations. In this case, the signals of each path are transmitted through different antenna sets, that is, antenna arrays. Looking at the processing of the signal input through the first path, the signal is converted into signal sequences having different or the same phase/magnitude by the phase/magnitude converters 412-1-1 to 412-1-M, and the amplifiers 414- After being amplified by 1-1 to 414-1-M, it is transmitted through antennas.

Referring to FIG. 4C, signals input to the analog beamforming unit 408 are transmitted through antennas through phase/magnitude conversion and amplification operations. In this case, the signals of each path are transmitted through the same antenna set, that is, an antenna array. Looking at the processing of the signal input through the first path, the signal is converted into signal sequences having different or the same phase/magnitude by the phase/magnitude converters 412-1-1 to 412-1-M, and the amplifiers 414- Amplified by 1-1 to 414-1-M. Then, to be transmitted through one antenna array, the amplified signals are summed by the summing units 416-1 to 416-M based on the antenna element, and then transmitted through the antennas.

FIG. 4B illustrates an example in which an independent antenna array for each transmission path is used, and FIG. 4C illustrates an example in which transmission paths share one antenna array. However, according to another embodiment, some transmission paths may use an independent antenna array, and other transmission paths may share one antenna array. Furthermore, according to another embodiment, a structure capable of adaptively changing according to a situation may be used by applying a structure that is switchable between transmission paths and antenna arrays.

V2X service can be divided into basic safety service and advanced service. The basic safety services may include detailed services such as vehicle notification (CAM or BSM) service, left turn notification service, front vehicle collision warning service, emergency vehicle approach notification service, forward obstacle warning service, and intersection signal information service. V2X information can be transmitted and received using a cast or groupcast transmission method. Advanced service not only strengthens QoS requirements than basic safety service, but also V2X using unicast and groupcast transmission methods in addition to broadcast so that V2X information can be transmitted and received within a specific vehicle group or V2X information between two vehicles. Request a way to transmit and receive information. For a service requiring a high level of reliability according to the enhanced QoS requirements, a method of transmitting feedback signaling for a transport packet is required. Advanced services may include detailed services such as platoon driving service, autonomous driving service, remote driving service, and extended sensor-based V2X service.

For V2X service, in ng-RAN (gNB) connected to 5G core network or E-UTRAN (ng-eNB) connected to 5G core network, UE performs V2X service through ng-RAN or E-UTRAN can do. As another embodiment, when a base station (ng-RAN or ng-eNB) is connected to an evolved packet core network (EPC), a V2X service may be performed through the base station. As another embodiment, when a base station (eNB) is connected to an evolved packet core network (EPC), a V2X service may be performed through the base station. At this time, the V2X wireless interface communication method that can be used for direct communication between terminals is at least one of unicast, groupcast, and broadcast, and wireless communication parameters suitable for the QoS requirements of V2X services when performing V2X transmission and reception in each communication method. Should provide a way to manage and set it up.

A system that performs direct communication between terminals based on LTE wireless communication defines that the transmitting terminal selects and operates parameters necessary for transmission by itself. In the LTE wireless communication base, V2X service messages for basic safety are transmitted in a direct communication method between terminals.The QoS requirements of basic safety V2X services are not strict, and even if basic safety services are diverse, QoS requirements between services are not diverse. The differentiation between the liver is not great. Therefore, even in the case of a mode in which the base station schedules radio resources to be used for direct communication between terminals based on LTE wireless communication, the base station does not need to obtain detailed QoS requirements information for the V2X service, and schedules radio resources. It is operated at the level of managing and setting parameters arbitrarily.

Advanced V2X service has various QoS requirements, and there is a large difference in QoS level required for each V2X service. In the case of a specific advanced V2X service, a radio resource and radio parameter for direct communication must be set to satisfy the strict QoS requirements of the service so that the service can be operated. Therefore, a system based on direct communication between terminals for supporting Advanced V2X service should provide a method of guaranteeing QoS of a service compared to a conventional system. For example, since the QoS level for reliability or delay time required for each service is different, it is necessary to operate the setting parameters of the direct communication radio bearer to ensure the required QoS level.

In the present invention, according to various embodiments, a configuration for determining QoS information corresponding to a sidelink radio access bearer for performing a direct vehicle-to-vehicle communication method required by a basic safety service or an advanced service and determining a feedback transmission corresponding to the QoS information A method of obtaining the parameters will be described.

5 shows a situation in which direct communication between terminals is performed using a sidelink RAT according to various embodiments of the present disclosure.

5(a) shows a scenario in which terminals in gNB coverage perform direct communication. In FIG. 5(a), configuration parameter information used to determine feedback signaling transmission of a sidelink radio bearer to be used for unicast, broadcast, or groupcast-based V2X packet transmission and reception between terminals is a System information message to an RRC dedicated message of gNB. It may be transmitted through or set in advance. The terminal performing direct communication may transmit QoS information corresponding to the V2X service to the base station and obtain configuration parameter information used to determine the feedback signaling transmission of the sidelink radio bearer from the base station. The terminal performing direct communication may determine QoS information corresponding to the V2X service and obtain a parameter used to determine the feedback signaling transmission of the sidelink radio bearer from preset information.

5(b) shows a scenario in which terminals in ng-eNB coverage perform direct communication. In Figure 5(b), the configuration parameter information of the sidelink radio bearer to be used for unicast, groupcast, or broadcast-based V2X packet transmission/reception between terminals is transmitted through a System information message or an RRC dedicated message of ng-eNB or is preset. There may be. The terminal performing direct communication may transmit QoS information corresponding to the V2X service to the ng-eNB and obtain configuration parameter information used to determine the feedback signaling transmission of the sidelink radio bearer from the base station. The terminal performing direct communication may determine QoS information corresponding to the V2X service and obtain a parameter used to determine the feedback signaling transmission of the sidelink radio bearer from preset information.

5(c) shows a scenario in which the terminal 120 in gNB coverage and the terminal 130 in eNB coverage perform direct communication. The configuration parameter information of a sidelink radio bearer to be used for transmitting and receiving a unicast, groupcast, or broadcast-based V2X packet between terminals may be transmitted through a system information message or an RRC dedicated message of the gNB or may be preset. The terminal performing direct communication may transmit QoS information corresponding to the V2X service to the gNB and obtain configuration parameter information used to determine the feedback signaling transmission of the sidelink radio bearer from the base station. The terminal performing direct communication may determine QoS information corresponding to the V2X service and obtain a parameter used to transmit the feedback signaling of the sidelink radio bearer from preset information.

5(d) shows a scenario in which terminals in eNB coverage perform direct communication. The configuration parameter information of the sidelink radio bearer to be used for V2X packet transmission and reception used for unicast, groupcast, or broadcast-based V2X packet transmission and reception between the terminals may be transmitted through a system information message or an RRC dedicated message of the eNB or may be preset. . The terminal performing direct communication may determine QoS information corresponding to the V2X service and obtain configuration parameter information used to determine the feedback signaling transmission of the sidelink radio bearer from the base station. The terminal performing direct communication may determine QoS information corresponding to the V2X service and obtain a parameter used to transmit the feedback signaling of the sidelink radio bearer from preset information.

According to various embodiments of the present invention, a method of obtaining sidelink QoS information for direct communication between terminals and a configuration parameter used for transmitting feedback signaling of a sidelink radio bearer corresponding to QoS is a unicast method of V2X. It can be used for message transmission and reception, broadcast transmission and reception of V2X messages, and groupcast transmission and reception of V2X messages. According to various embodiments of the present invention, configuration parameters used to transmit feedback signaling of a sidelink radio bearer performing direct communication between terminals are obtained from a base station, a method by which the terminal obtains preset information, and the terminal arbitrarily It may include at least one of setting methods.

According to various embodiments of the present disclosure, the setting for determining the feedback signaling transmission may be determined as at least one or a combination of the following.

(1) Whether to transmit feedback signaling for each cell may be designated. For example, if cell A is configured to transmit feedback signaling, a UE performing direct communication between UEs in cell A may transmit feedback signaling. For example, if Cell B is configured not to transmit feedback signaling, a UE performing direct communication between UEs in Cell B may not transmit feedback signaling. Whether the UE transmits feedback signaling in the cell depends on an indicator transmitted from the base station.

(2) Whether to transmit feedback signaling for each zone may be designated. Zones can be operated independently of the cell. The terminal may determine the zone based on its own location information. If zone A is configured to always transmit a feedback signal, a terminal that has performed direct communication between terminals in zone A can transmit feedback signaling. If it is configured not to transmit a feedback signal in zone B, a terminal that has performed direct communication between terminals in zone B may not transmit feedback signaling. Whether or not the terminal transmits feedback signaling in the corresponding zone depends on an indicator transmitted from the base station or according to indication information preset in the terminal.

(3) Whether to transmit feedback signaling may be designated for each group. If group A is configured to transmit feedback signaling for direct communication between terminals, the terminals in group A may transmit feedback signaling. If the group B is configured not to transmit the feedback signaling for direct communication between the terminals, the terminal in the group B may not transmit the feedback signaling. The terminal may obtain indication information indicating whether to transmit feedback signaling through the group configuration information. The group configuration information is information received from a base station, received from a terminal belonging to a group, or preset. Group configuration information including indication information indicating whether feedback signaling is transmitted may be transmitted to terminals in the group through one signaling.

(4) It is possible to set whether to transmit feedback signaling for each V2X application. For example, if it is configured to transmit feedback signaling for application A, when performing direct communication between terminals for application A, the terminal can always transmit feedback signaling. If it is configured not to transmit feedback signaling for Application B, if direct communication between terminals for application B is performed, the terminal may not always transmit feedback signaling. The terminal may receive V2X application information to transmit feedback signaling and V2X application information not to transmit feedback signaling through the base station or may be preset. Alternatively, information indicating whether to transmit feedback signaling for a V2X application may be obtained from an upper layer (eg, application layer, V2X layer) of the terminal.

(5) To satisfy the reliability requirements for V2X applications, it is configured to transmit feedback signaling. For example, if a reliability requirement is indicated for a V2X application, it can be configured to transmit feedback signaling for the packet of the application. For another example, if the reliability requirement for the V2X application is instructed to satisfy a certain threshold or higher, it may be configured to transmit feedback signaling for the packet of the application. For another example, if the reliability requirement for the V2X application is instructed to satisfy the latency requirement before the latency requirement, it can be configured to transmit feedback signaling for the corresponding application packet.

(6) To satisfy the latency requirement for V2X application, it is set not to transmit feedback signaling. For example, if a latency requirement is indicated for a V2X application, it can be configured not to transmit feedback signaling for a packet of the application. For another example, if the latency requirement for a V2X application is instructed to satisfy a specific threshold or more, it may be configured not to transmit feedback signaling for the corresponding application packet. For another example, if the latency requirement for the V2X application is instructed to satisfy the reliability requirement before the reliability requirement, it can be configured not to transmit the feedback signaling for the corresponding application packet.

The relationship between whether feedback signaling is transmitted and the reliability requirement or latency requirement is as follows. If the feedback signaling transmission is possible, the reliability can be increased because the packet can be retransmitted by determining whether the packet reception has failed. If feedback signaling transmission is possible, it may take time to determine whether a packet reception has failed and to retransmit the packet, so latency may increase. If feedback signaling transmission is not possible, there is no need to determine whether a packet reception has failed, and there is no need to retransmit the packet, so latency may not increase. If feedback signaling transmission is not possible, there is no need to determine whether or not the packet reception has failed, and since the packet is not retransmitted, reliability may be lowered.

According to an embodiment of the present invention, a parameter indicating a reliability request value may be set as PQI_R (ProSe 5QI Reliability). The PQI_R may indicate a reliability level required in a V2X application. The PQI_R may correspond to a parameter managed by an upper layer (eg, application layer, V2X layer) of the terminal.

According to an embodiment of the present invention, a parameter indicating a latency request value may be set to PQI_L (ProSe 5QI Latency). The PQI_L may indicate a latency level required in a V2X application. The PQI_L may correspond to a parameter managed by an upper layer (eg, application layer, V2X layer) of the terminal.

QoS requirements (PQI: ProSe QoS Indicator) of V2X service/application according to an embodiment of the present invention may be represented by a standardized 5QI value defined in the 3GPP standard as shown in [Table 1]. For example, a parameter indicating a reliability request value or a latency request value may be considered a case of operating corresponding to each packet error rate or packet delay budget of 5QI defined in [Table 1]. The terminal may set a reliability request value or a latency request value required by the V2X service based on the 5QI value.

5QI value Resource Type Default Priority Level Packet Delay Budget Packet Error Rate Default Maximum Data Burst Volume Default Averaging Window Example Services 82 Delay Critical GBR 19 10　ms 10 ^-4 255 bytes 2000 ms Discrete Automation (see TS　22.261　[22]) 83 22 10　ms 10 ^-4 1354 bytes
(NOTE 3) 2000 ms Discrete Automation (see TS 22.261 [22]), eV2X Messages (Platooning, Cooperative Lane Change with low LoA; see TS 22.186 [4]) 84 24 30　ms 10 ^-5 1354 bytes 2000 ms Intelligent transport systems (see TS　22.261　[22]) 85 21 5　ms 10 ^-5 255 bytes 2000 ms Electricity Distribution- high voltage (see TS 22.261 [22]), Remote Driving (see TS 22.186 [4]) 100 18 5　ms 10 ^-4 1354 bytes 2000 ms eV2X messages (Collision Avoidance, Platooning with high LoA (see TS　22.186　[4])

In an embodiment of the present invention, the terminal may provide a reliability request value or a latency request value for a radio bearer corresponding to the V2X application to the base station in response to the 5QI value. The terminal and the base station may obtain information on a reliability request value or a latency request value corresponding to the 5QI value from the V2X server.

In another embodiment of the present invention, the UE may provide a reliability request value (PQI_R) to a latency request value (PQI_L) for a radio bearer corresponding to the V2X application to the base station.

The parameter used to determine whether to transmit a feedback signal includes at least one of a feedback signaling transmission/feedback signaling non-transmission indicator (HARQ feedback enabled/disabled indicator), a reliability threshold, or a latency threshold. If the feedback signaling transmission indicator is set, the terminal can transmit and receive a feedback signal for a packet transmitted through a direct communication method. If the feedback signaling non-transmission indicator is set, the terminal may not transmit/receive a feedback signal for a packet transmitted through a direct communication method. If the reliability threshold or latency threshold is set, the UE may determine that it can transmit/receive a feedback signal or not transmit/receive a feedback signal for a packet transmitted in a direct communication method according to at least one or a combination of the conditions in the following [Table 2]. You can judge that there is.

Condition (a) Reliability request value higher than the reliability threshold (PQI_R)
Condition (b) A latency request value higher than the latency threshold (PQI_L)
Condition (c) A reliability request value higher than Reliability threshold_1, a latency request value lower than Latency threshold_1
Condition (d) Reliability request value lower than Reliability threshold_1, latency request value higher than Latency threshold_1
Condition (e) Absolute value or more of Reliability request value (PQI_R)
Condition (f) More than the absolute value of the latency request value (PQI_L)
Condition (g) Below absolute value of Reliability request value (PQI_R)
Condition (h) Less than the absolute value of the latency request value (PQI_L)

An example of the terminal operation for the above condition may be as follows. It goes without saying that various combinations of conditions other than the examples below are possible.

If condition (a) is satisfied, feedback signaling is transmitted

If condition (b) is satisfied, no feedback signaling is transmitted

If condition (a) is satisfied and condition (b) is not satisfied, feedback signaling is transmitted

If condition (a) is not satisfied and condition (b) is satisfied, feedback signaling is not transmitted

If condition (c) is satisfied, feedback signaling is transmitted

If condition (d) is satisfied, no feedback signaling is transmitted

If condition (e) is satisfied, feedback signaling is transmitted

If condition (h) is satisfied, feedback signaling is transmitted

When condition (e) is satisfied and condition (a) is satisfied, feedback signaling is transmitted

If condition (f) is satisfied and condition (b) is satisfied, feedback signaling is not transmitted

The parameter used to determine whether to transmit the feedback signal may be set through Uu signaling between the UE and the base station, pre-configuration in the UE, or may be set through sidelink signaling between the UE and the UE.

-Classification according to the RRC connection state of the terminal

-RRC_Connected UE is acquired in RRC dedicated signaling of the base station (e.g., RRC_Reconfiguration)

-RRC_Idle/RRC_Inactive UE acquired from V2X SIB

-RRC_Idle/RRC_Inactive UE can also be acquired in RRC dedicated signaling of the base station.

-Out-of-coverage UE is pre-configuration

-Method of using direct communication signaling between the terminal and the terminal (a method in which the transmitting terminal notifies the receiving terminal or between terminals belonging to the group)

-PC5 RRC signaling (e.g. AS configuration, SLRB configuration)

-PC5 MAC signaling (eg, MAC CE defined for PC5 configuration)

-PC5 PHY signaling (PSCCH SCI)

Next, a method of setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_CONNECTED state will be described with reference to FIGS. 6A to 6B.

Referring to FIG. 6A, UE1 600 and UE2 650 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 600 and UE2 605 may establish a PC5 unicast connection for this in step 611. UE1 600 may transmit a SidelinkUEInformation message including unicast flow information to the base station in step 612. Step 612 may correspond to a step of requesting SLRB configuration information necessary for direct communication between terminals, and may be used to request configuration information for determining whether feedback signaling is necessary for the flow according to an embodiment of the present invention. . Information that may be included in the signaling of step 612 may include at least one of the following [Table 3].

-DST ID list corresponding to V2X Application
-When the DST ID is classified in unicast, groupcast, or broadcast, only the DST ID can be included.
-When the DST ID is not classified in unicast, groupcast, or broadcast, it may include a DST ID and a cast type indicator.

-PQI or PQI_R or PQI_L corresponding to the DST ID: V2X application request value information
-When applying flow-based QoS modeling in sidelink
-QFI (flow identifier) and corresponding PQI
-QFI (flow identifier) and PQI_R to PQI_L corresponding thereto
-When packet-based QoS modeling is applied in sidelink
-PQI (if PQI is included in the packet to be transmitted)
-PQI_R to PQI_L (if PQI_R to PQI_L are included in a packet to be transmitted)

In a system in which the base station already has request value information corresponding to the V2X application, PQI, PQI_L, or PQI_R may not be included in step 612.

When the base station receives information on the V2X application in step 612, the base station may transmit configuration information for determining whether to signal feedback for a packet belonging to the V2X application to the terminal in step 613. The step 613 may correspond to a step of providing the SLRB setting required for direct communication between terminals, and in the embodiment of step 613, the setting information may include threshold information for determining whether feedback signaling is performed. Threshold information for determining whether feedback signaling corresponding to the V2X application is performed may include at least one of the following [Table 4].

-Reliability threshold
-Latency threshold
-The Reliability threshold or latency threshold corresponds to application information (DST ID)
-If DST ID can distinguish cast type, only DST ID can be included.
-If the DST ID cannot distinguish the cast type, it may include a cast type indicator along with the DST ID.

-The reliability threshold or latency threshold corresponds to sidelink flow information or sidelink packet information
-Sidelink flow information includes at least one of QFI, PQI, PQI_L, and PQI_R
-Sidelink packet information includes at least one of PQI, PQI_L, and PQI_R

-The reliability threshold or latency threshold corresponds to SLRB information

Upon receiving the configuration information (threshold value) for determining whether to transmit the feedback signaling in step 613, the UE may determine whether to transmit the feedback signaling by comparing the configuration information with the reliability request value or the latency request value of the packet (or flow). Conditions for determining whether to transmit the feedback signaling are shown in Table 2 above.

Referring to FIG. 6B, UE1 600 and UE2 605 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 600 and UE2 605 may establish a PC5 unicast connection for this in step 621. UE1 600 may transmit a SidelinkUEInformation message including unicast flow information to the base station 660 in step 622. Step 622 may correspond to a step of requesting SLRB configuration information necessary for direct communication between terminals, and may be used to request configuration information for determining whether feedback signaling is necessary for the flow according to an embodiment of the present invention. . Information that may be included in the signaling of step 622 may include at least one of [Table 3].

In a system in which the base station 660 already has request value information corresponding to the V2X application, PQI, PQI_L, or PQI_R may not be included in step 622.

Upon receiving the information on the V2X application in step 622, the base station 660 may transmit configuration information for determining whether to signal feedback for a packet belonging to the V2X application to the terminal in step 623. The step 623 may correspond to the step of providing the SLRB setting required for direct communication between the terminals, and in the embodiment of the step 623, the configuration information may include indicator information for determining whether feedback signaling is performed. In the embodiment of FIG. 6B, the base station 660 may determine whether to signal feedback based on the request value information corresponding to the V2X application and set the indicator.

Indicator information for determining whether feedback signaling corresponding to the V2X application is performed may include at least one of the following [Table 5].

-HARQ feedback enabled/disabled indicator corresponding to application information (DST ID)
-If DST ID can distinguish cast type, only DST ID can be included.
-If the DST ID cannot distinguish the cast type, it may include a cast type indicator along with the DST ID.

-HARQ feedback enabled/disabled indicator corresponding to sidelink flow information or sidelink packet information
-Sidelink flow information includes at least one of QFI, PQI, PQI_L, and PQI_R
-Sidelink packet information includes at least one of PQI, PQI_L, and PQI_R

-HARQ feedback enabled/disabled indicator corresponding to SLRB information

Upon receiving the configuration information (indicator) for determining whether to transmit the feedback signaling in step 623, the terminal may determine whether to transmit the feedback signaling of the packet (or flow) based on the configuration information. As an embodiment, the terminal may follow the feedback signaling transmission setting information determined by the base station 660 as it is. As another embodiment, the UE may determine whether to transmit the feedback signaling by referring to the feedback signaling transmission setting information and sidelink state information determined by the base station 660.

Next, a method of setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an RRC_IDLE state or a terminal in an RRC_INACTIVE state will be described with reference to FIGS. 7A to 7E.

Referring to FIG. 7A, UE1 700 and UE2 750 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 700 and UE2 750 may establish a PC5 unicast connection for this in step 701. UE1 700 may receive a V2X SIB message transmitted by the base station 760 in step 702. The V2X SIB message may include SLRB configuration information necessary for direct communication between terminals, and configuration information for determining whether feedback signaling is necessary for a sidelink flow or a sidelink packet corresponding to a V2X application according to an embodiment of the present invention. Can be used to transmit. Information that may be included in the signaling of step 702 may include at least one of [Table 4]. Upon receiving the configuration information (threshold value) for determining whether to transmit the feedback signaling in step 702, the UE may determine whether to transmit the feedback signaling by comparing the configuration information with the reliability request value or the latency request value of the packet (or flow). Conditions for determining whether to transmit the feedback signaling are shown in Table 2 above.

Referring to FIG. 7B, UE1 700 and UE2 750 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 700 and UE2 750 may establish a PC5 unicast connection for this in step 711. UE1 700 may receive a V2X SIB message transmitted by the base station 760 in step 712. The V2X SIB message may include SLRB configuration information necessary for direct communication between terminals, and configuration information for determining whether feedback signaling is necessary for a sidelink flow or a sidelink packet corresponding to a V2X application according to an embodiment of the present invention. Can be used to transmit. In the embodiment of step 712, the setting information may include indicator information for determining whether feedback signaling is performed. In the embodiment of FIG. 7B, the base station 760 may determine whether to signal feedback and set an indicator based on request value information corresponding to the V2X application. Indicator information for determining whether feedback signaling corresponding to the V2X application is performed may include at least one of [Table 5]. Upon receiving the configuration information (indicator) for determining whether to transmit the feedback signaling in step 712, the terminal may determine whether to transmit the feedback signaling of the packet (or flow) based on the configuration information. As an embodiment, the terminal may follow the feedback signaling transmission setting information determined by the base station 760 as it is. As another embodiment, the terminal may determine whether to transmit the feedback signaling by referring to the feedback signaling transmission setting information and sidelink state information determined by the base station 760.

As another embodiment of setting whether to transmit the feedback signaling corresponding to the V2X application to the RRC_IDLE terminal to the RRC_INACTIVE terminal, the base station 760 may indicate configuration information to be used by the RRC_CONNECTED terminal transitioning from RRC_IDLE to RRC_INACTIVE using RRC dedicated signaling. An embodiment of providing information on determining whether to transmit feedback signaling to be used in RRC_IDLE to RRC_INACTIVE through RRC dedicated signaling will be described with reference to FIGS. 7C to 7E.

Referring to FIG. 7C, UE1 700 and UE2 750 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 700 and UE2 750 may establish a PC5 unicast connection for this in step 721. The base station 760 may indicate by transmitting RRC Release signaling so that the RRC_CONNECTED terminal transitions to RRC_IDLE or transitions to RRC_INACTIVE. According to an embodiment of the present invention, the RRC Release signaling in step 722 may include SLRB configuration information required for direct communication by the UE, and determine whether feedback signaling is necessary for a sidelink flow or a sidelink packet corresponding to a V2X application. Can be used to transmit configuration information for. Information that may be included in the RRC Release signaling in step 722 may include at least one of [Table 4]. The terminal receiving the RRC Release signaling in step 722 may transition from RRC_IDLE to RRC_INACTIVE, and when performing direct communication between terminals in RRC_IDLE to RRC_INACTIVE, configuration information for determining whether to transmit the feedback signaling received in step 722 (threshold value ), it is possible to determine whether to transmit the feedback signaling by comparing the reliability request value to the latency request value of the packet (or flow). Conditions for determining whether to transmit the feedback signaling are shown in Table 2 above.

According to an embodiment of the present invention, the configuration information for determining whether to transmit the feedback signaling received in step 722 may be applied only to a new V2X application except for the V2X application previously used by the UE in RRC_CONNECTED. According to another embodiment, the configuration information for determining whether to transmit the feedback signaling received in step 722 may be applied to the V2X application and the new V2X application that the UE is already using in RRC_CONNECTED.

Referring to FIG. 7D, UE1 700 and UE2 750 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 700 and UE2 750 may establish a PC5 unicast connection for this in step 731. The base station 760 may indicate by transmitting RRC Release signaling so that the RRC_CONNECTED terminal transitions to RRC_IDLE or transitions to RRC_INACTIVE. According to an embodiment of the present invention, the RRC Release signaling in step 732 may include SLRB configuration information required for direct communication by the UE, and determine whether feedback signaling is necessary for a sidelink flow or a sidelink packet corresponding to a V2X application. Can be used to transmit configuration information for. In the embodiment of step 732, the setting information may include indicator information for determining whether feedback signaling is performed. In the embodiment of FIG. 7D, the base station 760 may determine whether to signal feedback based on request value information corresponding to the V2X application and set the indicator. Indicator information for determining whether feedback signaling corresponding to the V2X application is performed may include at least one of [Table 5]. The terminal receiving the RRC Release signaling in step 732 may transition from RRC_IDLE to RRC_INACTIVE, and when performing direct communication between terminals in RRC_IDLE to RRC_INACTIVE, configuration information for determining whether to transmit the feedback signaling received in step 732 (indicator ), it is possible to determine whether to transmit the feedback signaling of the packet (or flow). As an embodiment, the terminal may follow the feedback signaling transmission setting information determined by the base station 760 as it is. As another embodiment, the terminal may determine whether to transmit the feedback signaling by referring to the feedback signaling transmission setting information and sidelink state information determined by the base station 760.

According to an embodiment of the present invention, the configuration information for determining whether to transmit the feedback signaling received in step 732 may be applied only to a new V2X application except for the V2X application previously used by the UE in RRC_CONNECTED. According to another embodiment, the configuration information for determining whether to transmit the feedback signaling received in step 732 may be applied to the V2X application and the new V2X application that the UE is already using in RRC_CONNECTED.

Referring to FIG. 7E, UE1 700 and UE2 750 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 700 and UE2 750 may establish a PC5 unicast connection for this in step 741. As another embodiment in which the terminal provides configuration information to be used to determine whether to transmit feedback signaling for a V2X application to be used in RRC_IDLE to RRC_INACTIVE, the base station 760 may instruct the RRC_CONNECTED terminal to report information on the V2X application in step 742. have. In step 743, the terminal may transmit information on the V2X application to the base station 760 as in the embodiment of FIGS. 6A to 6B. In step 744, the base station 760 may provide configuration information on whether to transmit feedback signaling corresponding to the V2X application, as in the embodiments of FIGS. 6A to 6B. The base station 760 may transmit an RRC Release message so that the terminal transitions from RRC_IDLE to RRC_INACTIVE in step 745. According to various embodiments, step 745 may be omitted or the signaling of step 744 and the signaling of step 745 may be combined. The terminal may determine whether to transmit feedback signaling for a flow/packet of a V2X application based on direct communication between terminals performed by RRC_IDLE to RRC_INACTIVE based on the configuration information received in step 744.

According to an embodiment of the present invention, the configuration information for determining whether to transmit the feedback signaling received in step 744 may be applied only to a new V2X application except for the V2X application previously used by the UE in RRC_CONNECTED. According to another embodiment, the configuration information for determining whether to transmit the feedback signaling received in step 744 may be applied to the V2X application and the new V2X application that the UE is already using in RRC_CONNECTED.

According to an embodiment of the present invention, when the configuration information on whether to transmit the feedback signaling corresponding to the V2X application is obtained through a V2X SIB message and is obtained through RRC dedicated signaling, the terminal is based on the configuration information obtained in RRC dedicated signaling. It can work.

Next, a method of setting a parameter for determining whether to transmit feedback signaling in direct communication between terminals to a terminal in an OUT-OF-COVERAGE state will be described with reference to FIGS. 8A to 8B.

Referring to FIG. 8A, UE1 800 and UE2 850 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 800 and UE2 850 may establish a PC5 unicast connection for this in step 801. In step 802, the terminal may perform direct communication between terminals using the configuration information previously set for the V2X application. The preset configuration information may include configuration information for determining whether feedback signaling is necessary for a sidelink flow or a sidelink packet corresponding to a V2X application according to an embodiment of the present invention. Information set in advance to determine whether the feedback signaling is necessary may include at least one of [Table 4]. In step 802, the UE may determine whether to transmit the feedback signaling by comparing a Reliability request value or a Latency request value of a packet (or flow) based on the configuration information (threshold value) for determining whether to transmit the feedback signaling. Conditions for determining whether to transmit the feedback signaling are shown in Table 2 above.

Referring to FIG. 8B, UE1 800 and UE2 850 may transmit and receive V2X packets through direct communication between unicast-based terminals. The UE1 800 and UE2 850 may establish a PC5 unicast connection for this in step 811. In step 812, the terminal may perform direct communication between terminals using the configuration information previously set for the V2X application. The preset configuration information may include configuration information for determining whether feedback signaling is necessary for a sidelink flow or a sidelink packet corresponding to a V2X application according to an embodiment of the present invention. Information set in advance to determine whether the feedback signaling is necessary may include at least one of [Table 5]. The terminal may determine whether to transmit the feedback signaling of the packet (or flow) based on the configuration information (indicator) determining whether to transmit the feedback signaling in step 812.

According to an embodiment of the present invention, when the configuration information on whether to transmit the feedback signaling corresponding to the V2X application is obtained through pre-configuration and is obtained through signaling from the base station, the terminal is based on the configuration information acquired through the signaling of the base station. It can work.

Next, a method of setting a parameter for determining whether to transmit feedback signaling between terminals performing direct communication-based V2X packet transmission/reception will be described with reference to FIGS. 9A to 9C.

Configuration information for determining whether to transmit the feedback signaling of the sidelink flow or the sidelink packet proposed in the present invention may be exchanged using signaling between terminals. The configuration information for determining whether to transmit the feedback signaling may be transmitted by the transmitting terminal to the receiving terminal. The setting information may be transmitted by the group leader terminal to the group member terminal. The configuration information transmitted/received between terminals may include at least one of the parameters of [Table 6] to [Table 7]. Determination of whether to transmit the feedback signaling may be determined based on the method of FIGS. 6A to 8B according to the UE or the base station or preset information.

Inter-terminal signaling used to transmit and receive the configuration information may include at least one of the following.

(1) PC5 RRC signaling transmitted between terminals (e.g., AS configuration, SLRB configuration, SL SIB, SL MIB)

(2) PC5 MAC signaling transmitted between terminals (eg, Sidelink MAC CE)

(3) PC5 PHY signaling transmitted between terminals (e.g., PSCCH, Sidelink Control Information)

As another embodiment, terminals performing direct communication may obtain information on transmission of feedback signaling without separate signaling between terminals. According to an embodiment of the present invention, for a sidelink LCID corresponding to a sidelink flow or an SLRB of a sidelink packet, a sidelink LCID capable of transmitting feedback signaling and a sidelink LCID not transmitting feedback signaling may be preset. For example, SL LCIDs 4 to 10 may be set as sidelink LCIDs to transmit feedback signaling, and SL LCIDs 11 to 20 may be set to sidelink LCIDs not to transmit feedback signaling. The transmitting terminal and the receiving terminal may determine whether to transmit feedback signaling based on the LCID information of the SLRB. For the HARQ process ID corresponding to the sidelink flow or the SLRB of the sidelink packet according to an embodiment of the present invention, a sidelink HARQ process ID capable of transmitting feedback signaling and a sidelink HARQ process ID not transmitting feedback signaling are previously Can be set.

The information in [Table 6] may be included in the PC5 RRC signaling to PC5 MAC signaling and transmitted.

-DST ID list corresponding to V2X application
-If DST ID can distinguish cast type, only DST ID can be included.
-If the DST ID cannot distinguish the cast type, it may include a cast type indicator along with the DST ID.

-Sidelink flow information or sidelink packet information
-Sidelink flow information includes at least one of QFI, PQI, PQI_L, and PQI_R
-Sidelink packet information includes at least one of PQI, PQI_L, and PQI_R

-HARQ process ID list
-Logical channel ID list
-Logical channel group list
-SLRB list
-Feedback signaling transmission indicator (HARQ feedback enabled/disabled indicator)
-A threshold for determining whether to transmit feedback signaling (Reliability threshold to Latency threshold)

The information in [Table 7] may be included in PSCCH sidelink control information (SCI) and transmitted.

-Feedback signaling transmission indicator (HARQ feedback enabled/disabled indicator)
-Reliability request value (PQI_R) to latency request value (PQI_L)

Referring to FIG. 9A, UE1 900 may obtain information on whether to transmit feedback signaling for a sidelink flow corresponding to a unicast-based direct communication or a sidelink packet in step 901. Step 901 may refer to the embodiments of FIGS. 6 to 8. UE1 900 may transmit AS configuration to SLRB configuration information for the sidelink flow or sidelink packet to UE2 950 in step 902, and may include information on whether to transmit feedback signaling according to an embodiment of the present invention. The information transmitted in step 902 may include [Table 6]. In step 902, feedback configuration information that can be used when the receiving terminal transmits feedback signaling may also be transmitted. The signaling in step 902 corresponds to at least one of PC5 RRC unicast signaling and groupcast signaling. The UE2 950 may transmit a configuration complete message in step 903 as a response to the AS configuration to the SLRB configuration for the sidelink flow or sidelink packet.

Referring to FIG. 9B, UE1 900 may obtain information on whether to transmit feedback signaling for a sidelink flow corresponding to unicast-based direct communication or a sidelink packet in step 911. Step 911 may refer to the embodiments of FIGS. 6A to 8C. UE1 900 may transmit AS configuration to SLRB configuration information for the sidelink flow or sidelink packet to UE2 950 in step 912, and may include information on whether to transmit feedback signaling according to an embodiment of the present invention. The information transmitted in step 912 may include [Table 6]. In step 912, feedback configuration information that can be used when the receiving terminal transmits feedback signaling may also be transmitted. The signaling in step 912 corresponds to at least one of PC5 RRC broadcast signaling, unicast signaling, and groupcast signaling.

In the case of configuring whether to transmit feedback signaling in PC5 MAC signaling according to an embodiment of the present invention, the operation may be similar to that of FIGS. 9A to 9B. In this case, PC5 MAC signaling may be used instead of PC5 RRC signaling.

Referring to FIG. 9C, UE1 900 may obtain information on whether to transmit feedback signaling for a sidelink flow or a sidelink packet corresponding to unicast-based direct communication in step 921. Step 921 may refer to the embodiments of FIGS. 6 to 8. The UE1 900 may transmit SCI information on the sidelink flow or the sidelink packet to the UE2 950 in step 922, and may include information on whether to transmit feedback signaling according to an embodiment of the present invention. The information transmitted in step 922 may include [Table 7].

For example, information indicating whether to transmit feedback signaling in PSCCH SCI may be indicated by a HARQ feedback enabled indicator.

(In the case of a specific application or a specific cast type, it may be configured to transmit feedback signaling when a packet is not successfully received, but in the present invention, when a packet is successfully received, an ACK is transmitted, and when the packet is not successfully received, a NAK is transmitted. It will be described assuming the case of transmission)

When the HARQ feedback enabled indicator is set to 1, the receiving terminal recognizes that it is instructing to transmit a feedback signaling for a packet or flow corresponding to the SCI, and can transmit a feedback on the packet or flow. If the HARQ feedback enabled indicator is set to 0, the receiving terminal may recognize that it is instructing not to transmit feedback signaling for the packet or flow corresponding to the SCI, and may not transmit the feedback on the packet or the flow.

For another example, information indicating whether to transmit feedback signaling in PSCCH SCI may be expressed as PQI_R to PQI_L. Here, the PSCCH SCI includes at least one of PQI_R and PQI_L.

When receiving the SCI including PQI_R to PQI_L, the receiving terminal applies a Reliability threshold to PQI_R for packets or flows corresponding to the SCI, applies a Latency threshold to PQI_L, and provides feedback signaling based on the conditions of [Table 2]. You can decide whether to transmit.

Next, operations of the transmitting terminal and the receiving terminal according to an embodiment of the present invention will be described with reference to FIGS. 10A to 10B.

Referring to FIG. 10A, when a packet is transmitted in step 1001 from an upper layer of a transmitting terminal, the transmitting terminal may transmit the packet to the receiving terminal in step 1002. The transmitting terminal may determine whether to transmit the feedback signaling for the packet in step 1003 according to the scheme of FIGS. 6 to 9. If the packet is capable of transmitting the feedback signaling according to the determination in step 1003, the transmitting terminal may monitor the feedback channel in step 1004. If the packet is not to transmit feedback signaling according to the determination in step 1003, the transmitting terminal may proceed to step 1001.

Referring to FIG. 10B, the receiving terminal may receive a packet from the transmitting terminal in step 1011. The receiving terminal may determine whether the packet is a feedback signaling transmission target in step 1012 according to the scheme of FIGS. 6A to 9C. If the packet is a feedback signaling transmission target according to the determination in step 1012, the receiving terminal may transmit the feedback to the feedback channel in step 1013. According to the determination in step 1012, if the packet is not a target for transmitting the feedback signaling, the receiving terminal may proceed to step 1011.

Next, signal exchange between a terminal and a base station for processing a feedback signaling transmission resource according to an embodiment of the present invention will be described with reference to FIGS. 11A to 11C.

Referring to FIG. 11A, in step 1101, the UE may determine whether to transmit a feedback signaling for a sidelink packet or a flow. When feedback signaling transmission is required, the terminal may request a sidelink feedback resource required for the feedback signaling transmission from the base station in step 1102. The base station may allocate the sidelink feedback resource to the terminal in step 1103.

Referring to FIG. 11B, the base station may allocate a sidelink data resource and a sidelink feedback resource to a terminal in step 1111. The base station can allocate resources (packets and feedback) to be used in sidelink unicast or sidelink groupcast. In step 1112, the terminal may determine whether a sidelink flow or a sidelink packet is subject to feedback signaling transmission. When it is determined that feedback signaling transmission is necessary, the UE may transmit the feedback signaling using the sidelink feedback resource allocated from the base station in step 1111 in step 1113.

Referring to FIG. 11C, the base station may allocate a sidelink data resource pool and a sidelink feedback resource pool to a terminal in step 1121. The resource pool may correspond to a resource pool (packet and feedback) to be used in sidelink unicast or sidelink groupcast. In step 1122, the terminal may determine whether a sidelink flow or a sidelink packet is subject to feedback signaling transmission. When it is determined that feedback signaling transmission is necessary, the terminal may request the base station to allocate resources necessary for sidelink feedback transmission among the resource pool allocated in step 1121 from the step 1123. The base station may allocate resources necessary for the terminal to transmit sidelink feedback in step 1124.

The schemes of FIGS. 6A to 11C may be used as an embodiment for processing whether feedback signaling is transmitted for V2X packets transmitted/received through direct communication between unicast-based or groupcast-based terminals. In the case of groupcast, if there is no PC5 RRC unicast connection between terminals, after establishing a PC5 RRC unicast connection, configuration information for determining whether to transmit feedback signaling according to an embodiment of the present invention may be processed.

Next, a method of setting a parameter for determining application of the RLC AM mode or the RLC UM mode in V2X packet transmission and reception through direct communication between terminals according to various embodiments of the present invention will be described.

When applying the RLC AM mode, ARQ can be used to increase the reliability of packet transmission. For V2X applications where reliability is more important than latency, RLC AM mode can be applied. For V2X applications where latency is more important than reliability, RLC UM mode can be applied.

In the direct communication, the parameter for determining the application of the RLC AM mode to the application of the RLC UM mode is through at least one configuration information of RRC dedicated signaling, V2X SIB signaling, and pre-configuration as in the embodiments of FIGS. 6A to 9C. Can be obtained. The configuration information may be delivered through PC5 RRC signaling between terminals (eg, PC5 RRC bearer configuration) or Uu RRC signaling between terminals and base stations (eg, RRC reconfiguration for SL bearer configuration). In addition, a method of presetting an LCID for applying the RLC AM mode among SL LCIDs corresponding to the SLRB of the sidelink flow or the SLRB of the sidelink packet, and setting the LCID for applying the RLC UM mode in advance may also be applied. For example, SL LCIDs 4 to 10 may be set to apply the RLC AM mode. For example, SL LCIDs 11 to 20 may be set to apply the RLC UM mode.

In addition to the feedback signaling scheme, a HARQ repetition scheme for retransmitting a packet without feedback may be applied in response to a reliability request value or a latency request value for a sidelink packet or flow. The combination of the HARQ repetition scheme and the feedback signaling scheme may correspond to one of the following. Which combination to use can be determined by the terminal or the base station according to the service criteria and radio conditions for the sidelink packet or flow.

1. In case of HARQ feedback disabled, HARQ repetition disabled

2. In case of HARQ feedback disabled, HARQ repetition enabled

3. If HARQ feedback is enabled, HARQ repetition disabled

4. If HARQ feedback enabled, HARQ repetition enabled

When the HARQ repetition scheme is applied to sidelink unicast, the transmitting terminal may determine HARQ repetition and indicate whether repetition is present in SCI information and transmit it, and the receiving terminal may determine whether or not HARQ repetition with reference to SCI information.

When the HARQ repetition scheme and the feedback signaling scheme are used together as in #4, as an embodiment, feedback signaling may be transmitted for every packet (including an initial transmission packet and a packet transmitted after repetition). That is, ACK to NAK can be transmitted for each packet.

As another embodiment, feedback signaling may be configured to transmit an NAK when not all packets (including an initial transmission packet and a packet transmitted through repetition) are received. Feedback signaling may be configured to transmit an ACK upon receiving at least one packet (including an initial transmission packet and a packet transmitted after repetition).

Based on the various embodiments of FIGS. 6A to 11C, the operation of the terminal and the base station when the terminal or the base station determines HARQ feedback enabled or HARQ feedback disabled for SL flow or SL packet was examined. The operation of the terminal and the base station according to who (terminal or base station) will determine HARQ feedback enabled/disabled and who (terminal or base station) will allocate SL grant according to the determination of HARQ feedback enabled/disabled is shown in FIGS. 12 to 14 It will be described based on.

According to various embodiments of the present invention, HARQ feedback may be applied for each SL resource pool. For example, if HARQ feedback is enabled for SL resource pool A, a terminal receiving a packet transmitted using the resource of pool A may transmit HARQ feedback for the packet. For another example, if the SL resource pool B is set to HARQ feedback disabled, the terminal receiving a packet transmitted using the resource of the pool B may not transmit HARQ feedback for the packet. Therefore, in the case of SL flow or SL packet that is determined to require HARQ feedback, the terminal and the base station must be able to operate in order to select the resource of the SL resource pool set to HARQ feedback enabled. In the case of an SL flow or an SL packet determined that HARQ feedback is not required, the terminal and the base station should be able to operate to select a resource of the SL resource pool set to HARQ feedback disabled.

12 is a diagram illustrating a signal flow through which a terminal transmits HARQ feedback assistance information to a base station according to an embodiment of the present invention.

The embodiment of FIG. 12 may be used when a terminal in RRC_CONNECTED is allocated an SL grant from a base station or when the terminal itself allocates an SL grant according to an instruction of the base station. When the base station allocates the SL grant to the terminal (mode 1), the base station must be able to select an SL resource pool based on information on whether to transmit HARQ feedback of the terminal and allocate the SL grant from the pool. To this end, the base station needs to obtain information on whether to transmit HARQ feedback from the terminal. When the UE allocates an SL grant by itself according to the instruction of the base station (mode 2), the base station selects an SL resource pool based on information on whether to transmit HARQ feedback of the UE and instructs the UE to allocate the SL grant from the pool by itself. Should be able to To this end, the base station needs to obtain information on whether to transmit HARQ feedback from the terminal.

Referring to FIG. 12, in step 1201, the terminal 1200 may transmit a message including information about whether to transmit HARQ feedback to the base station 1250. The message used in step 1201 may include a SidelinkUEInformation message or a UEAssistanceInformation message. The SidelinkUEInformation message or UEAssistanceInformation message transmitted by the terminal to the base station may include at least one or a combination of the information shown in Table 8 below.

Destination Index Source Index Cast type (broadcast, groupcast, unicast) HARQ feedback enabled indication SL flow information SL logical channel information SL HARQ process information Interested SL resource allocation mode (mode 1, mode 2) SL QoS information

In step 1202, the base station may receive the information as shown in [Table 8] from the terminal and may determine that it is configured to transmit and receive HARQ feedback from the SL HARQ feedback enabled indication information. And the base station may decide to directly allocate the SL grant to the terminal (mode 1). If it is configured to transmit and receive the HARQ feedback, the base station may allocate an SL grant to the terminal from the SL resource pool configured as HARQ feedback enabled. The SL grant is at least one of dynamic SL grant, configured grant type 1, configured grant type 2, and SPS SL grant. In step 1203, the base station may transmit a message including configuration information for the SL grant to the terminal. The configuration for the SL grant transmitted from the base station to the terminal may include at least one or a combination of the information in the following [Table 9].

Destination index Source Index Cast type (broadcast, groupcast, unicast) SL resource pool for SL dynamic grant SL resource configuration for configured grant type 1 SL resource configuration for configured grant type 2 SL flow information SL logical channel information SL HARQ process information SL resource allocation mode (mode 1)

[Table 9] may be transmitted when the base station directly allocates the SL grant.

As another embodiment, in step 1202, the base station may determine that there is no need to transmit and receive HARQ feedback from the SL HARQ feedback enabled indication information of [Table 8] received from the terminal. And the base station may decide to directly allocate the SL grant to the terminal (mode 1). The base station may allocate an SL grant to the terminal from the SL resource pool configured as HARQ feedback disabled. The SL grant is at least one of dynamic SL grant, configured grant type 1, configured grant type 2, and SPS SL grant. In step 1203, the base station may transmit a message including configuration information for the SL grant to the terminal. The configuration for the SL grant may include at least one or a combination of the [Table 9] information.

As another embodiment, in step 1202, the base station may decide to instruct the UE to allocate the SL grant (mode 2). If it is configured to transmit and receive HARQ feedback based on the HARQ feedback enabled indication of [Table 8], the base station may provide SL resource pool information set to HARQ feedback enabled to the terminal. In step 1203, the base station may transmit a message including the SL grant configuration information of mode 2 instructing the terminal to allocate the SL grant to the terminal. The configuration for the SL grant may include at least one or a combination of the information of the following [Table 10].

Destination index Source Index Cast type (broadcast, groupcast, unicast) SL resource pool for SL allocation mode 2 SL flow information SL logical channel information SL HARQ process information SL resource allocation mode (mode 2)

As another embodiment, in step 1202, the base station may determine that there is no need to transmit and receive HARQ feedback from the SL HARQ feedback enabled indication information of [Table 8] received from the terminal. In addition, the base station may instruct mode 2 to allocate the SL grant itself. The base station may provide SL resource pool information set to HARQ feedback disabled to the terminal. In step 1203, the base station may transmit a message including the SL grant configuration information of mode 2 instructing the terminal to allocate the SL grant to the terminal. The configuration for the SL grant may include at least one or a combination of the [Table 10] information.

In step 1204, the UE may be assigned an SL grant from the base station based on the configuration information for the SL grant received from the base station (Tables 9 to 10) or may allocate the SL grant by itself from the SL resource pool according to the instruction of the base station. When the SL grant is allocated from the base station in step 1204 (mode 1), the SL grant may be selected from the SL resource pool corresponding to the HARQ feedback enabled by the base station. As another embodiment, when the SL grant is allocated from the base station in step 1204 (mode 1), the SL grant may be selected by the base station from the SL resource pool corresponding to HARQ feedback disabled. As another embodiment, when the UE allocates the SL grant by itself according to the instruction of the base station in step 1204 (mode 2), the UE may select the SL grant from the SL resource pool corresponding to the HARQ feedback enabled indicated by the base station. As another embodiment, when the terminal itself allocates the SL grant according to the instruction of the base station in step 1204 (mode 2), the terminal may select the SL grant from the SL resource pool corresponding to the HARQ feedback disabled indicated by the base station.

The terminal can transmit a packet in the SL grant allocated from the base station and/or the SL grant allocated by itself, and monitors the reception of HARQ feedback from the receiving terminal according to the HARQ feedback enabled indication of step 1201 (HARQ feedback enabled In case), an operation may be performed or an operation in which HARQ feedback reception is not monitored (in the case of HARQ feedback disabled) may be performed.

13 is a diagram illustrating an operation in which a terminal selects a sidelink resource by itself according to whether HARQ feedback is performed according to an embodiment of the present invention.

The embodiment of FIG. 13 may be used when a UE in RRC_IDLE or RRC_INACTIVE or OUT_OF_COVERAGE allocates an SL grant by itself.

Referring to FIG. 13, in step 1301, a UE in RRC_IDLE, RRC_INACTIVE or OUT_OF_COVERAGE may determine the necessity of sidelink resource allocation in order to transmit a packet. If resource allocation is required, in step 1302, the UE may determine the necessity of HARQ feedback for the SL flow or SL packet corresponding to the packet. The need for the HARQ feedback may be determined by at least one or a combination of [Table 1] to [Table 7]. In step 1303, if the terminal determines that HARQ feedback is required for the packet, in step 1304, the SL grant may be allocated from the sidelink resource pool configured as HARQ feedback enabled. In step 1306, the terminal may transmit a packet using the SL grant. Alternatively, in step 1303, if the UE determines that HARQ feedback is not required for the packet, it can allocate an SL grant from the sidelink resource pool set to HARQ feedback disabled in step 1305, and proceed to step 1306 to use the SL grant. Packets can be transmitted. In FIG. 13, the SL grant allocated by the UE may correspond to at least one of dynamic SL grant to configured grant type 1 to configured grant type 2 to SPS SL grant.

14 is a diagram illustrating an operation of a terminal according to an embodiment of the present invention.

Referring to FIG. 14, in step 1401, the UE may determine whether to transmit HARQ feedback for SL flow or SL packet. In step 1402, the UE may determine whether it is in the RRC_CONNECTED state. When the UE is in the RRC_CONNECTED state, the UE may request SL Grant allocation to the base station. If it is determined that the terminal is in the RRC_CONNECTED state according to the determination in step 1402, the terminal may transmit terminal assistance information for the SL grant to the base station in step 1403. Terminal Assistance information may be included in a SidelinkUEInformation message or a UEAssistanceInformation message and transmitted. The terminal assistance information transmitted in step 1403 may include information on whether to transmit HARQ feedback according to the determination in step 1401. That is, SL grant allocation request information for an SL flow or SL packet requiring HARQ feedback transmission or SL grant allocation request information for an SL flow or SL packet that does not require HARQ feedback transmission may be transmitted from the terminal to the base station. In step 1404, the terminal may receive the SL resource pool configuration from the base station. The SL resource pool configuration information may be transmitted in an RRC_ConnectionReconfiguration message or an RRC_Reconfiguration message transmitted from the base station to the terminal. In step 1405, the UE may determine whether the base station indicates a mode (mode 1) in which the SL grant is allocated in the SL resource pool configuration. If it is determined that the base station is instructed to operate in a mode in which the SL grant is allocated (mode 1), the UE may receive the SL grant from the base station in step 1406. Here, the base station allocates the SL grant from the sidelink resource pool corresponding to HARQ feedback enabled based on the information on whether to transmit the HARQ feedback transmitted by the terminal in step 1403 or the SL grant from the sidelink resource pool corresponding to HARQ feedback disabled. Can be assigned. In step 1407, the UE may transmit a packet for an SL flow or an SL packet using the SL grant. In step 1407, the terminal may process the packet according to the HARQ feedback enabled or HARQ feedback disabled information of the packet determined in step 1401. For example, if it is set to HARQ feedback enabled, the UE may wait for HARQ feedback for a packet transmitted from the SL grant. For example, if it is set to HARQ feedback disabled, the UE may not wait (monitor) for HARQ feedback for a packet transmitted from the SL grant.

In step 1405, the terminal may determine whether the base station indicates a mode (mode 2) in which the terminal itself allocates an SL grant in the SL resource pool configuration. If the base station determines that the UE has indicated the mode (mode 2) in which the UE itself allocates the SL grant, in step 1408, the UE allocates the SL grant itself from the sidelink resource pool instructed to allocate the SL grant in the SL resource pool configuration in step 1404 can do. Here, the sidelink resource pool indicated by the base station corresponds to a sidelink resource pool corresponding to HARQ feedback enabled or a sidelink resource pool corresponding to HARQ feedback disabled based on the information on whether to transmit HARQ feedback transmitted by the terminal in step 1403. Can be. The UE may allocate an SL grant from a sidelink resource pool corresponding to HARQ feedback enabled or a sidelink resource pool corresponding to HARQ feedback disabled according to the HARQ feedback enabled or HARQ feedback disabled information of the packet determined in step 1401. . In step 1409, the UE may transmit a packet corresponding to an SL flow or SL packet by using the SL grant allocated in step 1408. For example, if it is set to HARQ feedback enabled, the UE may wait for HARQ feedback for a packet transmitted from the SL grant. For example, if it is set to HARQ feedback disabled, the UE may not wait for HARQ feedback for a packet transmitted from the SL grant.

If the terminal is not in the RRC_CONNECTED state according to the determination in step 1402, the terminal may be in at least one of RRC_Idle, RRC_INACTIVE, or OUT_OF_COVERAGE. When the UE is in at least one of RRC_IDLE, RRC_INACTIVE, or OUT_OF_COVERAGE, the UE may allocate the SL grant itself from the SL resource pool. In step 1410, the UE may determine whether HARQ feedback is enabled based on information on whether HARQ feedback transmission is required for the SL flow or SL packet in step 1401. If it is determined in step 1410 that HARQ feedback enabled for the SL flow or SL packet is determined, in step 1411, the UE may allocate the SL grant from the sidelink resource pool corresponding to HARQ feedback enabled. In step 1412, the UE may transmit a packet corresponding to an SL flow or an SL packet by using the SL grant allocated in step 1411. In addition, in step 1412, the UE may wait for HARQ feedback for a packet transmitted from the SL grant. Alternatively, if it is determined in step 1410 that the HARQ feedback disabled for the SL flow or the SL packet is set, in step 1413, the UE may allocate the SL grant from the sidelink resource pool corresponding to HARQ feedback disabled. In step 1414, the UE may transmit a packet corresponding to an SL flow or SL packet by using the SL grant allocated in step 1413. In addition, the UE may not wait for HARQ feedback for a packet transmitted in the SL grant.

According to an embodiment of the present invention, an operation of a terminal performing a logical channel priority processing procedure for a logical channel corresponding to a HARQ feedback enabled SL flow or SL packet or a logical channel corresponding to a HARQ feedback disabled SL flow or SL packet is as follows. same.

The terminal may select a destination identifier having a logical channel satisfying the following conditions. The destination identifier may correspond to at least one of unicast, groupcast, and broadcast. The terminal may select one destination identifier having the highest transmission priority logical channel among logical channels satisfying the following conditions. If the above conditions are satisfied and there is at least one destination identifier having a logical channel having the highest transmission priority, the terminal may select one arbitrary destination.

(1) Logical channel has data to be transmitted

(2) There is a logical channel whose SBj value is greater than 0

The SBi value is initially set to 0 for each logical channel. At each time point in the logical channel priority processing procedure, the SBj value increases by (sPBR X T). sPBR corresponds to the sidelink prioritized bit rate. T corresponds to the time required from the point when the previous SBj value was calculated to the present. When the SBj value is larger than the sidelink bucket size (sPBR X sBSD), the SBj value is set to the sidelink bucket size. sBSD corresponds to the sidelink bucket size duration. The SBj value can be used to prevent starvation in which SL flow or SL packet of a corresponding logical channel cannot be transmitted because a transmission opportunity is not given for a logical channel.

(3) If configured grant type 1 is allowed for the SL grant, configured grant type 1 is set for the logical channel

(4) If HARQ feedback is allowed for the SL grant, HARQ feedback is enabled for the logical channel

For the destination identifier selected above, the terminal may select a logical channel that satisfies the following condition.

(1) Logical channel has data to be transmitted

(2) If configured grant type 1 is allowed for the SL grant, configured grant type 1 is set for the logical channel

(3) If HARQ feedback is allowed for the SL grant, HARQ feedback is enabled for the logical channel

The UE may transmit the SL flow or SL packet corresponding to the selected logical channel through the SL grant. As an embodiment, if the selected logical channel is set to HARQ feedback enabled, it may be transmitted through the HARQ feedback enabled SL grant. When HARQ feedback enabled is set and there are a plurality of selected logical channels, an SL flow or SL packet corresponding to the plurality of logical channels may be transmitted through the HARQ feedback enabled SL grant. As an embodiment, if the selected logical channel is set to HARQ feedback disabled, it may be transmitted through the HARQ feedback disabled SL grant. When the HARQ feedback disabled is set and there are a plurality of selected logical channels, the SL flow or SL packet corresponding to the plurality of logical channels may be transmitted through the HARQ feedback disabled SL grant.

According to an embodiment of the present invention, the UE is configured with HARQ feedback disabled or HARQ feedback enabled for a logical channel corresponding to an SL flow or SL packet, but a HARQ feedback disabled resource pool is set and a HARQ feedback enabled resource pool is set. If it is determined that it is not, the terminal may operate according to the HARQ feedback disabled setting set in the resource pool, ignoring the HARQ feedback disabled or HARQ feedback enabled setting configured for the logical channel corresponding to the SL flow or SL packet. That is, since it is determined that the resource pool is set to HARQ feedback disabled, the UE can perform an operation when HARQ feedback disabled is set for the SL flow or the logical channel of the SL packet.

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

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

These programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (electrically erasable programmable read only memory, EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs) or other forms of It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all of them. In addition, a plurality of configuration memories may be included.

In addition, the program is through a communication network composed of a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. It may be stored in an attachable storage device that can be accessed. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may access a device performing an embodiment of the present disclosure.

In the above-described specific embodiments of the present disclosure, components included in the disclosure are expressed in the singular or plural according to the presented specific embodiments. However, the singular or plural expression is selected appropriately for the situation presented for convenience of description, and the present disclosure is not limited to the singular or plural constituent elements, and even constituent elements expressed in plural are composed of the singular or in the singular. Even the expressed constituent elements may be composed of pluralities.

Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure is limited to the described embodiments and should not be determined, and should be determined by the scope of the claims as well as the equivalents of the claims to be described later.

Claims (1)

In the 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.

Images