CN113632526A

CN113632526A - Method and apparatus for supporting HARQ feedback transmission in device-to-device communication system

Info

Publication number: CN113632526A
Application number: CN202080022595.4A
Authority: CN
Inventors: 姜贤贞; 白祥圭; A.阿吉瓦尔
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2019-03-22
Filing date: 2020-03-19
Publication date: 2021-11-09
Anticipated expiration: 2040-03-19
Also published as: KR20200112652A; CN113632526B

Abstract

The present disclosure relates to fifth generation (5G) or Pre5G communication systems for supporting higher data transmission rates than fourth generation (4G) communication systems such as Long Term Evolution (LTE). The present disclosure can be applied to smart services, such as smart homes, smart buildings, smart cities, smart or connected cars, healthcare, digital education, retail enterprises, security and safety-related services, etc., based on 5G communication technology and IoT-related technologies. In addition, the operation method of the terminal in the wireless communication system may include the following steps: determining the service information required by the V2X application and determining the V2X transmission mode; determining the QoS information of the service required by the V2X application; acquiring the corresponding QoS information side link radio bearer configuration information; and, using the obtained side link radio bearer configuration information, sending and receiving V2X packets through a device-to-device communication method.

Description

Method and apparatus for supporting HARQ feedback transmission in device-to-device communication system

Technical Field

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

Background

In order to meet the increasing demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop an improved 5G or quasi-5G communication system. Accordingly, the 5G or quasi-5G communication system is also referred to as a "super 4G network" or a "post-LTE system".

The 5G communication system is considered to be implemented in a higher frequency (millimeter wave) band (for example, 60GHz band) in order to achieve a higher data rate. In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), full-dimensional MIMO (FD-MIMO), array antenna, analog beamforming, large antenna technology are discussed in the 5G communication system.

In addition, in the 5G communication system, development of improvement of a system network is ongoing based on advanced small cells, a cloud Radio Access Network (RAN), an ultra-dense network, device-to-device (D2D) communication, a wireless backhaul, a mobile network, cooperative communication, coordinated multipoint (CoMP), reception-side interference cancellation, and the like.

In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition decoding (SWSC) have also been developed as Advanced Coding Modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and Sparse Code Multiple Access (SCMA) as advanced access techniques.

The internet, which is a human-centric connectivity network in which humans produce and consume information, is now evolving into the internet of things (IoT), where distributed entities such as things exchange and process information without human intervention. Internet of everything (IoE) is the product of combining IoT technology and big data processing technology through a connection with a cloud server. Since IoT implementations require technical elements such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology", and "security technology", sensor networks, machine-to-machine (M2M) communication, Machine Type Communication (MTC), etc. have recently been studied. Such IoT environments can provide intelligent internet technology services that create new value for human life by collecting and analyzing data generated between connected things. IoT can be applied in a variety of fields including smart homes, smart buildings, smart cities, smart cars or networked cars, smart grids, healthcare, smart home appliances, and advanced medical services through fusion and combination between existing Information Technology (IT) and various industrial applications.

Accordingly, various efforts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor networks, Machine Type Communication (MTC), and machine-to-machine (M2M) communication may be implemented through beamforming, MIMO, and array antennas. The application of cloud Radio Access Network (RAN) as the big data processing technology described above may also be considered as an example of the convergence of 5G technology with IoT technology.

For the 5G system, a radio interface scheme for providing services with various quality of service (QoS) requirements is being discussed. For example, a direct communication method of a vehicle to all (V2X) terminals has been proposed. In addition, various discussions are being made to shorten communication time, increase reliability, and effectively support device-to-device communication.

Disclosure of Invention

Technical problem

In light of the above discussion, the present disclosure provides an apparatus and method for supporting data transmission and vehicle communication services that achieves high reliability and low latency requirements by providing a method for implementing a device-to-device communication scheme in a vehicle communication system.

Solution to the problem

In order to solve the above problem, a method of a first terminal in a wireless communication system according to an embodiment of the present disclosure may include: transmitting data to the second terminal through the side link; identifying whether hybrid automatic repeat request (HARQ) feedback is enabled for a sidelink; and monitoring HARQ feedback information on the data if it is identified that HARQ feedback is enabled for the sidelink.

Further, the first terminal in the wireless communication system according to the embodiment of the present disclosure may include: a transceiver; and a controller configured to: controlling the transceiver to transmit data to the second terminal through the side link; identifying whether hybrid automatic repeat request (HARQ) feedback is enabled for a sidelink; and controlling the transceiver to monitor HARQ feedback information on the data if it is identified that HARQ feedback is enabled for the sidelink. According to various embodiments of the present disclosure, a method of operating a terminal in a wireless communication system includes: determining, by the terminal, a V2X service requiring sidelink direct communication; determining quality of service (QoS) information required in a service; and acquiring reliability requirement or delay requirement information required in the service. The method includes controlling sidelink vehicle-to-all communication (V2X) wireless parameter configuration to send feedback signaling for transmission packets to meet reliability QoS requirements for V2X services by using sidelink direct communication. The method includes controlling sidelink vehicle-to-all communication (V2X) wireless parameter configuration to not send feedback signaling for transmission packets in order to meet the delayed QoS requirements of the V2X service by using sidelink direct communication. Acquiring, by a terminal transmitting or receiving a direct communication-based V2X service, radio parameter configuration information for determining whether to transmit feedback signaling includes: sending QoS information of the service to a base station, and obtaining parameter configuration information to determine whether to send a feedback signaling for a wireless bearer of the service; providing parameter configuration information through a base station and taking the parameter configuration information as a system parameter to determine whether to send a feedback signaling for a radio bearer corresponding to QoS information or not, and acquiring the parameter configuration information through a terminal; and acquiring the parameter configuration information through the terminal to determine whether to send feedback signaling for the radio bearer corresponding to the QoS information preconfigured by the terminal.

According to various embodiments of the present disclosure, a terminal apparatus in a wireless communication system according to various embodiments includes: a transceiver; and at least one processor functionally associated with the transceiver. If it is determined that the terminal is within the coverage of the base station, the at least one processor controls the terminal to: determining QoS information required in the V2X service; requesting parameter configuration information from the base station to determine whether to send feedback signaling for the radio bearer corresponding to the QoS information; and the control terminal is assigned parameter configuration information. If it is determined that the terminal is not within the coverage of the base station, the at least one processor controls the terminal to: determining QoS information required in the V2X service; and obtaining parameter configuration information to determine whether to send feedback signaling for a radio bearer corresponding to the preconfigured QoS information.

According to various embodiments of the present disclosure, a method of operating a terminal in a wireless communication system may include: determining service information required for the V2X application and determining QoS information of a service required for the V2X application; acquiring parameter configuration information to determine whether to send a feedback signaling for a side link radio bearer corresponding to the QoS information; and transmitting or receiving the V2X packet in the direct communication scheme by using the acquired parameter configuration information of the sidelink radio bearer.

According to various embodiments of the present disclosure, a terminal in a wireless communication system may include: a transceiver configured to transmit or receive data; and at least one processor functionally associated with the transceiver, wherein the at least one processor: determining service information required by the V2X application; determining QoS information of a service required by the V2X application; acquiring parameter configuration information to determine whether to send a feedback signaling for a side link radio bearer corresponding to the QoS information; and transmitting or receiving the V2X packet in the direct communication scheme by using the acquired parameter configuration information of the sidelink radio bearer.

Advantageous effects of the invention

Various embodiments of the present disclosure provide an apparatus and method capable of supporting a vehicle communication service requiring various qualities of service (QoS) by using device-to-device communication in a vehicle communication system, thereby enabling reliability of vehicle communication and delay requirement values.

Effects obtainable by the present disclosure are not limited to the above-described effects, and other effects not mentioned may be clearly understood by those skilled in the art through the following description.

Drawings

Fig. 1 illustrates a wireless communication system in accordance with various embodiments of the present disclosure;

fig. 2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure;

fig. 3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure;

fig. 4a illustrates a configuration of a communication unit in a wireless communication system according to various embodiments of the present disclosure;

fig. 4b illustrates an example in which a separate antenna array is used independently for each transmission path in an analog beamforming unit of a communication unit in a wireless communication system, in accordance with various embodiments of the present disclosure;

fig. 4c shows an example in which one antenna array is shared by transmission paths in an analog beamforming unit of a communication unit in a wireless communication system, according to various embodiments of the present disclosure;

fig. 5 illustrates a scenario in which device-to-device communication is performed by using a sidelink Radio Access Technology (RAT), according to various embodiments of the present disclosure;

fig. 6a illustrates a signaling procedure for configuring a terminal in an RRC-CONNECTED (RRC CONNECTED) state with parameters for determining whether to transmit feedback signaling in device-to-device communication, according to various embodiments of the present disclosure;

fig. 6b illustrates a signaling procedure for configuring a terminal in an RRC-CONNECTED state with parameters for determining whether to transmit feedback signaling in device-to-device communication, according to various embodiments of the present disclosure;

fig. 7a illustrates a signaling procedure for configuring a terminal in an RRC-IDLE (RRC IDLE) state or a terminal in an RRC-INACTIVE (RRC INACTIVE) state with parameters for determining whether to send feedback signaling in device-to-device communication, according to various embodiments of the present disclosure;

fig. 7b illustrates a signaling procedure for configuring a terminal in an RRC-IDLE state or a terminal in an RRC-INACTIVE state with parameters for determining whether to send feedback signaling in device-to-device communication, according to various embodiments of the present disclosure;

fig. 7c illustrates a signaling procedure for configuring a terminal in an RRC-IDLE state or a terminal in an RRC-INACTIVE state with parameters for determining whether to send feedback signaling in device-to-device communication, according to various embodiments of the present disclosure;

fig. 7d illustrates a signaling procedure for configuring a terminal in an RRC-IDLE state or a terminal in an RRC-INACTIVE state with parameters for determining whether to send feedback signaling in device-to-device communication, according to various embodiments of the present disclosure;

fig. 7e illustrates a signaling procedure for configuring a terminal in an RRC-IDLE state or a terminal in an RRC-INACTIVE state with parameters for determining whether to send feedback signaling in device-to-device communication, according to various embodiments of the present disclosure;

fig. 8a illustrates a signaling procedure for configuring a terminal in an OUT-OF-COVERAGE state with parameters for determining whether to send feedback signaling in device-to-device communication, in accordance with various embodiments OF the present disclosure;

fig. 8b illustrates a signaling procedure for configuring a terminal in an OUT-OF-COVERAGE state with parameters for determining whether to send feedback signaling in device-to-device communication, in accordance with various embodiments OF the present disclosure;

fig. 9a illustrates a signaling procedure for determining whether to send feedback signaling between terminals sending and receiving V2X packets based on a direct communication configuration, according to various embodiments of the present disclosure;

fig. 9b illustrates a signaling procedure for determining whether to send feedback signaling between terminals sending and receiving V2X packets based on a direct communication configuration, according to various embodiments of the present disclosure;

fig. 9c illustrates a signaling procedure for determining whether to send feedback signaling between terminals sending and receiving V2X packets based on a direct communication configuration, according to various embodiments of the present disclosure;

fig. 10a illustrates the operation of a transmission terminal according to various embodiments of the present disclosure;

figure 10b illustrates the operation of a receiving terminal according to various embodiments of the present disclosure;

fig. 11a illustrates a signaling procedure between a terminal and a base station for handling feedback signaling transmission resources according to various embodiments of the disclosure;

fig. 11b illustrates a signaling procedure between a terminal and a base station for handling feedback signaling transmission resources according to various embodiments of the disclosure;

fig. 11c illustrates a signaling procedure between a terminal and a base station for handling feedback signaling transmission resources according to various embodiments of the disclosure;

fig. 12 shows a signal flow diagram for a terminal to transmit HARQ feedback assistance information to a base station, in accordance with various embodiments of the present disclosure;

fig. 13 illustrates operations according to various embodiments of the present disclosure in which a terminal selects a sidelink resource by itself depending on whether HARQ feedback is sent; and

fig. 14 illustrates operations of a terminal according to various embodiments of the present disclosure.

Detailed Description

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. Unless the context clearly differs, singular expressions may include plural expressions. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. These terms, which are defined in commonly used dictionaries, can be interpreted as having a meaning that is consistent with their contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. In some cases, even terms defined in the present disclosure should not be construed to exclude embodiments of the present disclosure.

Hereinafter, various embodiments of the present disclosure will be described based on a hardware method. However, various embodiments of the present disclosure include techniques that use both hardware and software, and thus, various embodiments of the present disclosure may not exclude software.

In the following, the present disclosure relates to an apparatus and method for obtaining configuration parameters for determining transmission of feedback signaling for a sidelink radio bearer corresponding to quality of service (QoS) requirements for vehicle-to-all (V2X) communication services in a wireless communication system. The feedback signaling may include, for example, HARQ feedback. In particular, the present disclosure provides a technique for satisfying QoS levels required for various V2X services based on a method for obtaining configuration parameters for determining transmission of feedback signaling for sidelink radio bearers for sidelink direct communication between vehicles to all (V2X) terminals in a wireless communication system.

In the following description, for convenience of explanation, terms indicating signals, terms indicating channels, terms indicating control information, terms indicating network entities, terms indicating elements of devices, and the like are exemplified. Accordingly, the present disclosure is not limited to the following terms, and other terms having the same technical meaning may be used.

Furthermore, the present disclosure includes terms used to explain various embodiments in some communication protocols (e.g., third generation partnership project (3GPP)), but these terms correspond to examples only. The various embodiments can also be easily modified and then applied to other communication systems.

Fig. 1 illustrates a wireless communication system in accordance with various embodiments of the present disclosure. In fig. 1, base station 110, terminal 120, and terminal 130 are shown as part of a node that uses wireless channels in a wireless communication system. Although only one base station is shown in fig. 1, another base station that is the same as or similar to base station 110 may also be included. Although fig. 1 shows only two terminals, another terminal that is the same as or similar to terminal 120 and terminal 130 may be included.

Base station 110 is the network infrastructure that provides wireless access to

terminals

120 and 130. The base station 110 has a coverage area defined as a particular geographic area based on the distance over which the base station is able to transmit signals. The base station 110 may also be referred to as an "Access Point (AP)", "base station (eNB)", "fifth generation (5G) node", "5G base station (gtnodeb or gNB)", "wireless point", "transmission/reception point (TRP)" or other terms having technical meanings equivalent thereto.

Each of the

terminals

120 and 130 is a device used by a user and communicates with the base station 110 through a wireless channel. In some cases, at least one of the

terminals

120 and 130 may be operated without user involvement. That is, at least one of the

terminals

120 and 130 is a device configured to perform Machine Type Communication (MTC) and may not be carried by a user. Each of the

terminals

120 and 130 may be referred to as a "User Equipment (UE)", a "mobile station", "subscriber station", "remote terminal", "wireless terminal", "user equipment", or other terms having technical meanings equivalent thereto.

Base station 110 and

terminals

120 and 130 may transmit and receive wireless signals in the sub-6 GHz (sub 6GHz) band and the millimeter wave (mmWave) band (e.g., 28GHz, 30GHz, 38GHz, or 60 GHz). To improve channel gain, base station 110 and

terminals

120 and 130 may perform beamforming. Beamforming may include transmit beamforming and receive beamforming. That is, the base station 110 and the

terminals

120 and 130 may provide directivity to a transmission signal or a reception signal. For this purpose, the base station 110 and the

terminals

120 and 130 may select the serving

beams

112, 113, 121, and 131 through a beam search process or a beam management process. The communication after the selection of the service beams 112, 113, 121, and 131 may be performed on resources having a quasi co-location (QCL) relationship with the resources used to transmit the service beams 112, 113, 121, and 131.

The first antenna port and the second antenna port may be considered to have a QCL relationship therebetween if the large scale characteristics of the channel on which the symbol has been transmitted on the first antenna port can be inferred from the channel on which the symbol has been transmitted on the second antenna port. For example, the large-scale properties may include at least one of delay spread, doppler shift, average gain, average delay, and spatial receiver parameters.

Fig. 2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. The configuration shown in fig. 2 can be considered to be that of the base station 110. The term "… element" or the end of a word such as "… or (… machine)" or "… er (… machine)" used hereinafter may denote an element that processes at least one function or operation, and it may be implemented by hardware, software, or a combination of hardware and software.

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

The wireless communication unit 210 performs a function of transmitting and receiving a signal through a wireless channel. For example, the wireless communication unit 210 performs a conversion function between a baseband signal and a bitstream according to a physical layer protocol of the system. For example, when transmitting data, the wireless communication unit 210 generates a complex symbol by encoding and modulating a transmission bit stream. Also, when receiving data, the wireless communication unit 210 reconstructs a received bit stream by demodulating and decoding a baseband signal.

Also, the wireless communication unit 210 up-converts a baseband signal into a Radio Frequency (RF) band signal, then transmits the converted RF band signal through an antenna, and down-converts an RF band signal received through the antenna into a baseband signal. For this purpose, the wireless communication unit 210 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and the like. In addition, the wireless communication unit 210 may include a plurality of transmission/reception paths. Further, the wireless communication unit 210 may include at least one antenna array configured with a plurality of antenna elements.

In terms of hardware, the wireless communication unit 210 may be configured with a digital unit and an analog unit, and the analog unit may include a plurality of sub-units according to an operating power, an operating frequency, and the like. The digital unit may be implemented as at least one processor, such as a Digital Signal Processor (DSP).

The wireless communication unit 210 may transmit and receive signals as described above. Accordingly, the entirety or a portion of the wireless communication unit 210 may be referred to as a "transmitter", "receiver", or "transceiver". Further, in the following description, transmission and reception through a wireless channel may be understood to include the above-described processing performed by the wireless communication unit 210.

The backhaul communication unit 220 provides an interface to perform communication with other nodes within the network. That is, the backhaul communication unit 220 converts a bitstream transmitted from a base station to another node (e.g., 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 bitstream.

The storage unit 230 stores data such as basic programs for the operation of the base station, application programs, and configuration information. The storage unit 230 may be configured as a volatile memory, a non-volatile memory, or a combination of volatile and non-volatile memories. The storage unit 230 provides the stored data according to a request of the controller 240.

The controller 240 controls the overall operation of the base station. For example, the controller 240 transmits and receives signals through the wireless communication unit 210 or the backhaul communication unit 220. In addition, the controller 240 records and reads data in and from the storage unit 230. Further, the controller 240 may perform functions of a protocol stack required in the communication protocol. According to another embodiment, 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, controller 240 may transmit Radio Resource Control (RRC) configuration information to terminal 110. The controller 240 may transmit the 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 later.

Fig. 3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure. The configuration shown in fig. 3 may be understood as the configuration of the terminal 120 or the terminal 130. The term "… element" or the end of a word such as "… or (… machine)" or "… er (… machine)" used hereinafter may denote an element that processes at least one function or operation, and it may be implemented by hardware, software, or a combination of hardware and software.

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

The communication unit 310 performs a function of transmitting/receiving a signal through a wireless channel. For example, the communication unit 310 performs a conversion function between a baseband signal and a bitstream according to a physical layer protocol of the system. For example, when transmitting data, the communication unit 310 generates a complex symbol by encoding and modulating a transmission bit stream. Also, when receiving data, the communication unit 310 reconstructs a received bit stream by demodulating and decoding a baseband signal. Also, the communication unit 310 up-converts a baseband signal into an RF band signal, then transmits the converted RF band signal through an antenna, and down-converts an 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 comprise at least one antenna array comprising a plurality of antenna elements. In terms of hardware, the communication unit 310 may be configured as a digital circuit and an analog circuit (e.g., a Radio Frequency Integrated Circuit (RFIC)). The digital circuitry and the analog circuitry may be implemented as a single package. Further, the communication unit 310 may include a plurality of RF chains. In addition, 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. Further, the communication unit 310 may include a plurality of communication modules to support a plurality of different radio access technologies. For example, the different wireless access technologies may include Bluetooth Low Energy (BLE), Wireless Fidelity (Wi-Fi), Wi-Fi gigabytes (WiGig), cellular networks (e.g., Long Term Evolution (LTE)), and so on. In addition, the different frequency bands may include an ultra high frequency (SHF) (e.g., 2.5GHz, 3.5GHz, or 5GHz) band and a millimeter (mm) wave (e.g., 60GHz) band.

The communication unit 310 transmits and receives signals as described above. Accordingly, all or a portion of the communication unit 310 may be referred to as a "transmitter," receiver, "or" transceiver. Further, in the following description, transmission and reception through a wireless channel may be understood to include the above-described processing performed by the communication unit 310.

The memory 320 stores data such as basic programs for the operation of the terminal, application programs, and configuration information. The storage unit 320 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. The storage unit 320 provides the stored data according to a request of the controller 330.

The controller 330 controls the overall operation of the terminal. For example, the controller 330 transmits and receives signals through the communication unit 310. In addition, the controller 330 records and reads data in and from the storage unit 320. Further, the controller 330 may perform the functions of a protocol stack required in the communication protocol. To this end, the controller 330 may include at least one processor or microprocessor, or may be part of a processor. Further, the controller 330 and a part of the communication unit 310 may be referred to as a Communication Processor (CP).

According to various embodiments, when the terminal 120 performs a sidelink direct communication with another terminal, the controller 330 may cause the terminal 120 to: determining service information required by the V2X application, and determining QoS information of the V2X service; acquiring configuration parameters required for determining whether to send feedback signaling for a side link radio bearer corresponding to QoS information; and transmitting or receiving the V2X packet in the direct communication scheme by using the acquired configuration information required to determine whether to transmit the feedback signaling for the sidelink radio bearer. For example, the controller 330 may control the terminal to perform operations according to various embodiments described later.

Fig. 4a to 4c illustrate configurations of communication units in a wireless communication system according to various embodiments of the present disclosure. Fig. 4a to 4c show examples of detailed configurations of the wireless communication unit 210 shown in fig. 2 or the communication unit 310 shown in fig. 3. In particular, fig. 4a to 4c show elements configured for performing beamforming, which elements are part of the wireless communication unit 210 of fig. 2 or the communication unit 310 of fig. 3.

Referring to fig. 4a, the wireless communication unit 210 or the communication unit 310 includes a coding and modulation unit 402, a digital beam forming unit 404, a plurality of transmission paths 406-1 to 406-N, and an analog beam forming unit 408.

The coding and modulation unit 402 performs channel coding. For channel coding, at least one of a Low Density Parity Check (LDPC) code, a convolutional code, and a polar code may be used. The coding and modulation unit 402 generates modulation symbols by performing constellation mapping.

The digital beamforming unit 404 performs beamforming on the digital signals (e.g., modulation symbols). For this purpose, the digital beam forming unit 404 multiplies the beam forming weights by the modulation symbols. The beamforming weights are used to change the magnitude and phase of the signals and may be referred to as "precoding matrices", "precoders", or the like. The digital beam forming unit 404 outputs the modulation symbols that have been digitally beamformed to the plurality of transmission paths 406-1 to 406-N. The modulation symbols may be multiplexed or the same modulation symbol may be provided to multiple transmission paths 406-1 to 406-N according to a multiple-input multiple-output (MIMO) transmission scheme.

The plurality of transmission paths 406-1 to 406-N convert digital signals that have been digitally beamformed 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) operator, a Cyclic Prefix (CP) inserter, a DAC, and an up-converter. The CP inserter is designed for an Orthogonal Frequency Division Multiplexing (OFDM) scheme, and may be excluded in a case where a different physical layer scheme, such as filter bank multi-carrier (FBMC), is applied. That is, the multiple transmission paths 406-1 to 406-N provide independent signal processing procedures for multiple streams generated by digital beamforming, respectively. However, depending on the implementation, a portion of the elements of each of the plurality of transmission paths 406-1 to 406-N may be shared.

The analog beamforming unit 408 performs beamforming on the analog signal. For this purpose, the digital beam forming unit 404 multiplies the beam forming weights by the analog signals. The beamforming weights are used to change the magnitude and phase of the signals. Specifically, the analog beam forming unit 408 may be configured as shown in fig. 4b or as shown in fig. 4c according to a connection structure between the plurality of transmission paths 406-1 to 406-N and the antenna.

Referring to fig. 4b, the signal input to the analog beam forming unit 408 is subjected to phase/magnitude conversion and amplification operations and then transmitted through an antenna. The signals in the paths are transmitted via different antenna groups, i.e. antenna arrays, respectively. Regarding the processing of the signals input through the first path, the signals are converted into signal streams including signals having the same phase or magnitude or different phases or magnitudes by the phase/magnitude converters 412-1-1 to 412-1-M, the converted signal streams amplified by the amplifiers 414-1-1 to 414-1-M, and then the amplified signal streams are transmitted through the antennas, respectively.

Referring to fig. 4c, the signal input to the analog beam forming unit 408 is subjected to phase/size conversion and amplification operations and then transmitted through an antenna. The signals in the paths are transmitted through the same set of antennas, i.e. an antenna array. With respect to the processing of the signal input through the first path, the signal is converted into a signal stream including signals having the same phase or magnitude or different phases or magnitudes by the phase/magnitude converters 412-1-1 to 412-1-M, and the converted signal is amplified by the amplifiers 414-1-1 to 414-1-M. For transmission through a single antenna array, the amplified signals are added together by adders 416-1 to 416-M based on the antenna elements, and then the added signals are transmitted through antennas, respectively.

Fig. 4b shows an example in which a separate antenna array is used for each transmission path, and fig. 4c shows an example in which one antenna array is shared by the transmission paths. However, according to another embodiment, some transmission paths may use separate antenna arrays, while the remaining transmission paths may share a single antenna array. Furthermore, according to yet another embodiment, a switchable structure between the transmission path and the antenna array may be applied, allowing the use of a structure that can be adaptively changed according to circumstances.

The V2X service can be classified into a basic security service and a high-level service. In addition to the vehicle notification (CAM or BSM) service, the basic safety service may also correspond to detailed services such as a left turn notification service, a preceding vehicle collision warning service, an emergency vehicle passage notification service, a front obstacle warning service, and an intersection traffic light information service, and may transmit or receive the V2X information by using a broadcast, unicast, or multicast transmission scheme. Advanced services not only have enhanced QoS requirements compared to basic security services, but also require a method capable of transmitting or receiving V2X information by using a unicast and multicast transmission scheme instead of a broadcast transmission scheme, thereby allowing transmission or reception of V2X information in a specific vehicle group or between two vehicles. In light of the enhanced QoS requirements, there is a need for a method that can send feedback signaling for transport packets for services that require high reliability. Advanced services may correspond to detailed services such as formation services, automated driving services, remote driving services, and extended sensor-based V2X services.

For V2X service, the UE may perform V2X service in ng-RAN or E-UTRAN through ng-RAN (gnb) connected to the 5G core network or E-UTRAN (ng-eNB) connected to the 5G core network. In another embodiment, the V2X service may be performed by a base station in a case where the base station (ng-RAN or ng-eNB) is connected to an evolved packet core network (EPC). In yet another embodiment, the V2X service may be performed by a base station (eNB) in a case where the eNB is connected to an Evolved Packet Core (EPC). The V2X wireless interface communication scheme available for device-to-device communication may correspond to at least one of unicast, multicast, and broadcast, and when V2X transmission or reception is performed in each of the communication schemes, a method for managing and configuring wireless communication parameters suitable for QoS requirements of V2X services needs to be provided.

A system for performing device-to-device communication based on LTE wireless communication defines a transmission terminal to select and operate parameters required for transmission by the terminal itself. When LTE wireless communication is used, V2X service messages for basic security are transmitted in a device-to-device communication scheme. The QoS requirements of the basic security V2X service are not strict, and even if there are various basic security services, the QoS requirements are not diverse and the difference between services is not large. Therefore, even the mode in which the base station schedules the radio resources to be used in the device-to-device communication based on the LTE wireless communication operates in such a manner that the base station schedules the radio resources without acquiring the specific QoS requirement information of the V2X service, and the terminal randomly manages and configures the parameters.

Advanced V2X services have various QoS requirements, and there is a large difference between the QoS levels required for V2X services. In the case of a particular advanced V2X service, the service can only be run if the radio resources and radio parameters used for direct communication are configured to meet the strict QoS requirements of the service. Therefore, there is a need to provide a method of guaranteeing service QoS for a device-to-device communication-based system supporting the advanced V2X service, compared to the conventional system. For example, the QoS levels of reliability and delay required for the service are different. Therefore, in order to guarantee the required QoS level, it is necessary to operate configuration parameters of the direct communication radio bearer.

In this disclosure, a method will be described that determines QoS information corresponding to a sidelink radio access bearer of a direct vehicle-to-vehicle communication scheme required for performing basic security services or advanced services, and obtains configuration parameters for determining feedback transmission corresponding to the QoS information, according to various embodiments.

Fig. 5 illustrates a scenario in which device-to-device communication is performed by using a sidelink RAT, according to various embodiments of the present disclosure.

Fig. 5 (a) shows a scenario in which terminals within the coverage of the gNB perform direct communication. In (a) of fig. 5, configuration parameter information for determining whether to transmit feedback signaling for transmitting or receiving a sidelink radio bearer of a V2X packet based on unicast, broadcast, and multicast between terminals may be pre-configured, or may be transmitted through an RRC dedicated message or a system information message of a gNB. The terminal performing the direct communication may transmit QoS information corresponding to the V2X service to the base station, and may acquire configuration parameter information for determining whether to transmit feedback signaling of the sidelink radio bearer from the base station. The terminal performing the direct communication may determine QoS information corresponding to the V2X service and may acquire a parameter for determining whether to transmit feedback signaling for a sidelink radio bearer from the preconfigured information.

Fig. 5 (b) shows a scenario in which terminals within the coverage of the ng-eNB perform direct communication. In (b) of fig. 5, configuration parameter information of a sidelink radio bearer for transmitting or receiving a V2X packet based on unicast, multicast or broadcast between terminals may be pre-configured, or may be transmitted through an RRC dedicated message or a system information message of ng-eNB. A terminal performing direct communication may transmit QoS information corresponding to the V2X service to the ng-eNB and may acquire configuration parameter information for determining whether to transmit feedback signaling of a sidelink radio bearer from the base station. The terminal performing the direct communication may determine QoS information corresponding to the V2X service and may acquire a parameter for determining whether to transmit feedback signaling for a sidelink radio bearer from the preconfigured information.

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

Fig. 5 (d) shows a scenario in which terminals within the coverage of the eNB perform direct communication. The configuration parameter information of the sidelink radio bearer for transmitting or receiving the V2X packet based on unicast, multicast or broadcast between terminals may be preconfigured or may be transmitted through an RRC dedicated message or a system information message of the eNB. The terminal performing the direct communication may determine QoS information corresponding to the V2X service and may acquire configuration parameter information for determining whether to transmit feedback signaling of the sidelink radio bearer from the base station. The terminal performing the direct communication may determine QoS information corresponding to the V2X service and may acquire parameters for transmitting feedback signaling of the sidelink radio bearer from the preconfigured information.

According to various embodiments of the present disclosure, a method for acquiring sidelink QoS information related to performing a sidelink for device-to-device communication and acquiring configuration parameters for transmitting feedback signaling of a sidelink radio bearer corresponding to QoS may be used in unicast V2X message transmission or reception, broadcast V2X message transmission or reception, or multicast V2X message transmission or reception. According to various embodiments of the present disclosure, configuration parameters for sending feedback signaling for a sidelink radio bearer performing device-to-device communication may be acquired by at least one of a method for acquiring configuration parameters from a base station, a method for acquiring provisioning information by a terminal, and a method for randomly configuring configuration parameters by a terminal.

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

(1) Whether to send feedback signaling may be specified for each cell. For example, if configured to transmit feedback signaling in cell a, a terminal performing device-to-device communication in cell a may transmit the feedback signaling. For example, if it is configured not to transmit feedback signaling in cell B, a terminal performing device-to-device communication in cell B may not transmit feedback signaling. Whether the terminal transmits the feedback signaling in the corresponding cell follows the indicator transmitted by the base station.

(2) Whether to transmit feedback signaling may be specified for each region. The region may operate independently of the cell. The terminal may determine the region based on the location information of the terminal. A terminal performing device-to-device communication in the area a may transmit feedback signaling if it is configured to always be able to transmit the feedback signaling in the area a. The terminal performing the device-to-device communication in the area B may not transmit the feedback signaling if it is configured not to transmit the feedback signaling in the area B. Whether the terminal transmits the feedback signaling in the corresponding region may follow an indicator transmitted by the base station or follow indication information pre-configured in the terminal.

(3) Whether to send feedback signaling may be specified for each group. Terminals in group a may send feedback signaling if configured to send feedback signaling for device-to-device communication in group a. Terminals in group B may not send feedback signaling if configured not to send feedback signaling for device-to-device communication in group B. The terminal may acquire indication information indicating whether to transmit the feedback signaling through the group configuration information. The group configuration information is received from the base station, received from terminals belonging to a group, or is pre-configured. Group configuration information including indication information indicating whether to transmit feedback signaling may be transmitted to terminals in the group through one-time signaling.

(4) Whether to send feedback signaling may be configured for each V2X application. For example, if the feedback signaling of application a is configured to be transmitted, the terminal may always transmit the feedback signaling when performing the device-to-device communication of application a. If the feedback signaling of application B is configured not to be transmitted, the terminal may not always transmit the feedback signaling when performing the device-to-device communication of application B. The terminal may receive information on the V2X application for which feedback signaling is to be transmitted and information on the V2X application for which feedback signaling is not to be transmitted from the base station, or may configure the same information for the terminal in advance. Alternatively, the terminal may acquire information indicating whether to transmit feedback signaling regarding the V2X application at a higher layer (e.g., an application layer or a V2X layer) of the terminal.

(5) Is configured to send feedback signaling in order to meet the reliability requirements of the V2X application. For example, if a reliability requirement is indicated for a V2X application, it may be configured to send feedback signaling for the corresponding application packet. As another example, if the reliability requirement of the V2X application is indicated to meet a certain threshold or higher, it may be configured to send feedback signaling for the corresponding application packet. As yet another example, if the reliability requirements of the V2X application are indicated to meet precedence over delay requirements, then sending feedback signaling for the corresponding application packet may be configured.

(6) Is configured not to send feedback signaling in order to meet the delay requirements of the V2X application. For example, if a delay requirement is indicated for a V2X application, it may be configured not to send feedback signaling for the corresponding application packet. As another example, if the delay requirement indicating the V2X application meets a certain threshold or higher, it may be configured not to send feedback signaling for the corresponding application packet. As yet another example, if the delay requirement of the V2X application is indicated to meet the prioritized reliability requirement, it may be configured not to send feedback signaling for the corresponding application packet.

The relation between whether feedback signaling is sent or not and the reliability requirement or delay requirement is as follows. If the feedback signaling can be sent, it can be determined whether the reception of the packet failed, and the packet can be retransmitted. Therefore, reliability can be improved. If the feedback signaling can be sent, time may be required to determine if the reception of the packet failed and resend the packet. Therefore, delay may be increased. If no feedback signaling can be sent, there is no need to determine if the reception of the packet failed and there is no need to retransmit the packet. Therefore, delay may not be increased. If no feedback signaling can be sent, there is no need to determine if the reception of the packet failed and the packet is not retransmitted. Therefore, reliability may be reduced.

According to an embodiment of the present disclosure, the parameter indicating the reliability requirement value may be configured as ProSe 5QI reliability (PQI _ R). The PQI _ R may represent the level of reliability required for V2X applications. The PQI _ R may correspond to a parameter managed at a higher layer (e.g., an application layer or a V2X layer) of the terminal.

According to an embodiment of the present disclosure, the parameter indicating the delay requirement value may be configured as a ProSe 5QI delay (PQI _ L). PQI _ L may represent the level of delay required for V2X application. The PQI _ L may correspond to a parameter managed at a higher layer (e.g., an application layer or a V2X layer) of the terminal.

The QoS requirements (ProSe QoS indicator; PQI) of V2X services/applications according to an embodiment of the present disclosure may be represented by standardized 5QI values defined in the 3GPP standards, as shown in [ table 1 ]. For example, a case may be considered in which a parameter indicating a reliability requirement value or a delay requirement value is operated to correspond to a packet error rate or a packet delay budget of 5QI defined in [ table 1], respectively. The terminal can configure the required reliability requirement value or delay requirement value in the V2X service based on the 5QI value.

[ Table 1]

In an embodiment of the present disclosure, the terminal may provide the base station with a reliability requirement value or a delay requirement value corresponding to the radio bearer applied by V2X, which corresponds to a 5QI value. The terminal and the base station can acquire information on the reliability requirement value or the delay requirement value corresponding to the 5QI value from the V2X server.

In another embodiment of the present disclosure, the terminal may provide the base station with a reliability requirement value (PQI _ R) or a delay requirement value (PQI _ L) corresponding to a radio bearer applied by V2X.

The parameter for determining whether to send feedback signaling includes at least one of a feedback signaling transmission/feedback signaling non-transmission indicator (HARQ feedback enable/disable indicator), a reliability threshold, or a delay threshold. The terminal may transmit or receive a feedback signal for a packet transmitted in the direct communication scheme if the feedback signaling transmission indicator is configured. The terminal may not transmit or receive a feedback signal for a packet transmitted in the direct communication scheme if the feedback signaling non-transmission indicator is configured. If the reliability threshold or the delay threshold is configured, the terminal may determine that the terminal may transmit or receive a feedback signal or may not transmit or receive a feedback signal with respect to a packet transmitted in the direct communication scheme according to at least one or a combination of conditions in the following [ table 2 ].

[ Table 2]

An example of the terminal operation for the above conditions is as follows. In addition to the following examples, combinations of various conditions are also possible.

If condition (a) is satisfied, sending feedback signaling

If the condition (b) is satisfied, no feedback signaling is sent

If the condition (a) is satisfied but the condition (b) is not satisfied, transmitting feedback signaling

If the condition (a) is not satisfied and the condition (b) is satisfied, no feedback signaling is transmitted

If condition (c) is satisfied, sending feedback signaling

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

If condition (e) is satisfied, sending feedback signaling

If condition (h) is satisfied, sending feedback signaling

If condition (e) is satisfied and condition (a) is satisfied, then feedback signaling is sent

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

The parameter for determining whether to transmit the feedback signaling may be configured by Uu signaling between the terminal and the base station, may be pre-configured for the terminal by pre-configuration, or may be configured by sidelink signaling between the terminals.

-classification based on RRC connected state of terminal

RRC _ Connected UE acquisition by RRC dedicated signalling of the base station (e.g. no RRC _ Reconfiguration)

RRC _ Idle/RRC _ Inactive UE acquisition from V2X SIB

RRC Idle/RRC Inactive UEs may also be obtained through RRC dedicated signaling of the base station.

Out-of-coverage UE acquisition by pre-configuration

Method of using signaling in device-to-device communication (method in which a transmitting terminal notifies a receiving terminal or terminals belonging to a group of mutual notification)

PC5 RRC signaling (e.g. AS configuration or SLRB configuration)

PC5 MAC signaling (e.g. MAC CE defined for PC5 configuration)

PC5 PHY Signaling (PSCCH SCI)

Next, with reference to fig. 6a and 6b, a method for configuring parameters for determining whether to transmit feedback signaling in device-to-device communication for a terminal in an RRC-CONNECTED state will be described.

Referring to fig. 6a, UE 1600 and UE 2650 may send or receive V2X packets through unicast-based device-to-device communication. In operation 611, the UE 1600 and the UE 2605 may configure a PC5 unicast connection for this purpose. In operation 612, the UE 1600 may transmit a sidelinkue information message including unicast stream information to the base station. Operation 612 may correspond to an operation of requesting sidelink radio bearer (SLRB) configuration information required for device-to-device communication, and according to an embodiment of the present disclosure, may be used to request the configuration information to determine whether feedback signaling needs to be performed for the corresponding flow. The information that may be included in the signaling of operation 612 may include at least one of the following [ table 3 ].

[ Table 3]

In a system in which the base station already has the required value information corresponding to the V2X application, PQI _ L, or PQI _ R may not be included in operation 612.

When the base station receives information about the V2X application in operation 612, the base station may transmit configuration information allowing determination of whether to perform feedback signaling on a packet belonging to the V2X application to the terminal in operation 613. Operation 613 may correspond to an operation of providing an SLRB configuration required for device-to-device communication, and in an embodiment of operation 613, the configuration information may include threshold information allowing determination of whether to perform feedback signaling. The threshold information for determining whether to perform the feedback signaling corresponding to the V2X application may include at least one of the following [ table 4 ].

[ Table 4]

In operation 613, the terminal having received the configuration information (threshold) allowing determination as to whether to transmit the feedback signaling may determine whether to transmit the feedback signaling by comparing the configuration information with the reliability requirement value or the delay requirement value of the packet (or stream). The conditions for determining whether to send feedback signaling are as shown in table 2 above.

Referring to fig. 6B, UE 1600 and UE 2650 may send or receive V2X packets through unicast-based device-to-device communication. In operation 621, UE 1600 and UE 2650 may configure a PC5 unicast connection for this. In operation 622, UE 1600 may send a sidelinkue information message including unicast stream information to base station 660. Operation 622 may correspond to an operation of requesting SLRB configuration information required for device-to-device communication, and according to an embodiment of the present disclosure, may be used to request the configuration information to determine whether feedback signaling needs to be performed for the corresponding flow. The information that may be included in the signaling of operation 622 may include at least one of the above [ table 3 ].

In a system where the base station 660 already has the required value information corresponding to the V2X application, the PQI, PQI _ L, or PQI _ R may not be included in operation 622.

When the base station 660 receives information on the V2X application in operation 622, the base station may transmit configuration information allowing determination of whether to perform feedback signaling on a packet belonging to the V2X application to the terminal in operation 623. Operation 623 may correspond to an operation of providing SLRB configuration required for device-to-device communication, and in an embodiment of operation 623, the configuration information may include indicator information allowing determination of whether to perform feedback signaling. In the embodiment of fig. 6B, the base station 660 may determine whether to perform feedback signaling based on the requirement value information corresponding to the V2X application, and may configure an indicator.

The indicator information for determining whether to perform the feedback signaling corresponding to the V2X application may include at least one of the following [ table 5 ].

[ Table 5]

In operation 623, the terminal having received the configuration information (indicator) allowing determination as to whether to transmit the feedback signaling may determine whether to transmit the feedback signaling of the packet (or stream) based on the configuration information. In an embodiment, the terminal may follow the configuration information determined by the base station 660 as to whether to send feedback signaling without change. In another embodiment, the terminal may determine whether to transmit feedback signaling by considering the side link state information and configuration information (which is determined by the base station 660) regarding whether to transmit feedback signaling.

Next, with reference to fig. 7a to 7e, a method for configuring a parameter for determining whether to transmit feedback signaling in device-to-device communication for a terminal in an RRC _ IDLE state or a terminal in an RRC _ INACTIVE state will be described.

Referring to fig. 7a, UE 1700 and UE 2750 may send or receive V2X packets through unicast-based device-to-device communication. In operation 701, UE 1700 and UE 2750 may configure a PC5 unicast connection for this purpose. In operation 702, the UE 1700 may receive a V2X System Information Block (SIB) message transmitted by the base station 760. The V2X SIB message may include SLRB configuration information required for device-to-device communication, and according to embodiments of the present disclosure, may be used to transmit the configuration information to determine whether feedback signaling needs to be performed for sidelink flows or sidelink packets corresponding to the V2X application. The information that may be included in the signaling of operation 702 may include at least one of [ table 4] above. In operation 702, a terminal having received configuration information (threshold) allowing determination as to whether to transmit feedback signaling may determine whether to transmit feedback signaling by comparing the configuration information with a reliability requirement value or a delay requirement value of a packet (or a stream). The conditions for determining whether to send feedback signaling are as shown in table 2 above.

Referring to fig. 7b, UE 1700 and UE 2750 may send or receive V2X packets through unicast-based device-to-device communication. In operation 711, the UE 1700 and the UE 2750 may configure a PC5 unicast connection for this purpose. In operation 712, the UE 1700 may receive the V2X SIB message transmitted by the base station 760. The V2X SIB message may include SLRB configuration information required for device-to-device communication, and according to embodiments of the present disclosure, may be used to transmit the configuration information to determine whether feedback signaling needs to be performed for sidelink flows or sidelink packets corresponding to the V2X application. In an embodiment of operation 712, the configuration information may include indicator information allowing a determination as to whether to perform feedback signaling. In the fig. 7b embodiment, base station 760 may determine whether to perform feedback signaling based on the requirement value information corresponding to the V2X application, and may configure the indicator. The indicator information for determining whether to perform the feedback signaling corresponding to the V2X application may include at least one of the above [ table 5 ].

In operation 712, the terminal having received the configuration information (indicator) allowing determination as to whether to transmit the feedback signaling may determine whether to transmit the feedback signaling of the packet (or stream) based on the configuration information. In an embodiment, the terminal may follow the configuration information determined by the base station 760 as to whether to send feedback signaling without change. In another embodiment, the terminal may determine whether to transmit feedback signaling by considering the side link state information and configuration information determined by the base station 760 as to whether to transmit feedback signaling.

In another embodiment of configuring whether to send feedback signaling corresponding to the V2X application for an RRC _ IDLE terminal or an RRC _ INACTIVE terminal, the base station 760 may use RRC dedicated signaling to indicate configuration information to be used by the terminal after transitioning from the RRC _ CONNECTED state to the RRC _ IDLE state or the RRC _ INACTIVE state. An embodiment of providing configuration information through RRC dedicated signaling to determine whether to transmit feedback signaling to be used in an RRC IDLE state or an RRC INACTIVE state will be described with reference to fig. 7c to 7 e.

Referring to fig. 7c, UE 1700 and UE 2750 may send or receive V2X packets through unicast-based device-to-device communication. In operation 721, the UE 1700 and the UE 2750 may configure a PC5 unicast connection for this purpose. The base station 760 may instruct the RRC _ CONNECTED terminal to transition to the RRC _ IDLE state or the RRC _ INACTIVE state by transmitting RRC release signaling. According to an embodiment of the present disclosure, the RRC release signaling of operation 722 may include SLRB configuration information required for direct communication of the terminal, and may be used to transmit the configuration information to determine whether feedback signaling needs to be performed for a sidelink flow or a sidelink packet corresponding to the V2X application. The information that may be included in the RRC release signaling of operation 722 may include at least one of the above [ table 4 ].

The terminal, having received the RRC release signaling of operation 722, may transition to an RRC _ IDLE state or an RRC _ INACTIVE state, and when device-to-device communication is performed in the RRC _ IDLE state or the RRC _ INACTIVE state, the terminal may determine whether to transmit feedback signaling by comparing reliability requirement values or delay requirement values of packets (or streams) based on configuration information (threshold value) received in operation 722, which allows determination as to whether to transmit feedback signaling. The conditions for determining whether to send feedback signaling are as shown in table 2 above.

According to an embodiment of the present disclosure, the configuration information received in operation 722, which allows the determination as to whether to transmit feedback signaling, may be applied only to a new V2X application other than the V2X application already used by the terminal in the RRC _ CONNECTED state. According to another embodiment, the configuration information received in operation 722, which allows determining whether to transmit feedback signaling, may be applied to a new V2X application and a V2X application already used by a terminal in an RRC _ CONNECTED state.

Referring to fig. 7d, UE 1700 and UE 2750 may send or receive V2X packets through unicast-based device-to-device communication. In operation 731, the UE 1700 and the UE 2750 may configure a PC5 unicast connection for this purpose. The base station 760 may instruct the RRC _ CONNECTED terminal to transition to the RRC _ IDLE state or the RRC _ INACTIVE state by transmitting RRC release signaling. The RRC release signaling of operation 732 may include SLRB configuration information required for direct communication of the terminal and may be used to transmit the configuration information to determine whether feedback signaling needs to be performed for a sidelink flow or a sidelink packet corresponding to the V2X application, according to an embodiment of the present disclosure. In an embodiment of operation 732, the configuration information may include indicator information allowing determination as to whether to perform feedback signaling. In the embodiment of fig. 7d, base station 760 may determine whether to perform feedback signaling based on the requirement value information corresponding to the V2X application, and may configure the indicator. The indicator information for determining whether to perform the feedback signaling corresponding to the V2X application may include at least one of the above [ table 5 ].

The terminal having received the RRC release signaling of operation 732 may transition to an RRC _ IDLE state or an RRC _ INACTIVE state, and when performing device-to-device communication in the RRC _ IDLE state or the RRC _ INACTIVE state, the terminal may determine whether to transmit feedback signaling of a packet (or a stream) based on configuration information (indicator) received in operation 732, which allows determination as to whether to transmit the feedback signaling. In an embodiment, the terminal may follow the configuration information determined by the base station 760 as to whether to send feedback signaling without change. In another embodiment, the terminal may determine whether to transmit feedback signaling by considering the side link state information and configuration information determined by the base station 760 as to whether to transmit feedback signaling.

According to an embodiment of the present disclosure, the configuration information received in operation 732, which allows the determination as to whether to transmit feedback signaling, may be applied only to a new V2X application other than the V2X application already used by the terminal in the RRC _ CONNECTED state. According to another embodiment, the configuration information received in operation 732 allowing the determination as to whether to transmit feedback signaling may be applied to a new V2X application and a V2X application already used by a terminal in an RRC _ CONNECTED state.

Referring to fig. 7e, UE 1700 and UE 2750 may send or receive V2X packets through unicast-based device-to-device communication. In operation 741, UE 1700 and UE 2750 may configure a PC5 unicast connection for this purpose. In another embodiment that provides configuration information for determining whether to send feedback signaling for a V2X application used by a terminal in an RRC IDLE state or an RRC INACTIVE state, the base station 760 may instruct the RRC _ CONNECTED terminal to report information about the V2X application at operation 742. As in the embodiment of fig. 6a or 6b, the terminal may transmit information regarding the V2X application to the base station 760 in operation 743. As in the embodiment of fig. 6a or 6b, base station 760 may provide configuration information in operation 744 as to whether to send feedback signaling corresponding to the V2X application. In operation 745, the base station 760 may send an RRC release message to allow the terminal to transition to an RRC IDLE state or an RRC INACTIVE state. According to various embodiments, operation 745 may be omitted, or the signaling of operation 744 and the signaling of operation 745 may be combined. The terminal may determine, based on the configuration information received in operation 744, whether to transmit feedback signaling for the flows/packets of the V2X application based on device-to-device communication performed in the RRC _ IDLE state or the RRC _ INACTIVE state.

According to an embodiment of the present disclosure, the configuration information received in operation 744, which allows the determination as to whether to transmit the feedback signaling, may be applied only to a new V2X application other than the V2X application already used by the terminal in the RRC _ CONNECTED state. According to another embodiment, the configuration information received in operation 744 that allows determining whether to transmit feedback signaling may be applied to a new V2X application and a V2X application that has been used by a terminal in an RRC _ CONNECTED state.

According to an embodiment of the present disclosure, in a case where configuration information on whether to transmit feedback signaling corresponding to the V2X application is acquired through the V2X SIB message and acquired through RRC dedicated signaling, the terminal may be operated based on the configuration information acquired through RRC dedicated signaling.

Next, with reference to fig. 8a and 8b, a method for configuring a parameter for determining whether to transmit feedback signaling in device-to-device communication for a terminal in an OUT-OF-COVERAGE state will be described.

Referring to fig. 8a, UE 1800 and UE 2850 may send or receive V2X packets through unicast-based device-to-device communication. In operation 801, the UE 1800 and the UE 2850 may configure a PC5 unicast connection for this. In operation 802, the terminal may perform device-to-device communication by using configuration information pre-configured for V2X application. According to an embodiment of the present disclosure, the preconfigured configuration information may include configuration information for determining whether feedback signaling needs to be performed for a sidelink flow or sidelink packet corresponding to the V2X application. The information preconfigured for determining whether feedback signaling needs to be performed may comprise at least one of [ table 4] above. In operation 802, the terminal may determine whether to transmit feedback signaling by comparing reliability requirement values or delay requirement values of packets (or streams) based on configuration information (threshold) allowing determination as to whether to transmit feedback signaling. The conditions for determining whether to send feedback signaling are as shown in table 2 above.

Referring to fig. 8b, UE 1800 and UE 2850 may send or receive V2X packets through unicast-based device-to-device communication. In operation 811, the UE 1800 and the UE 2850 may configure a PC5 unicast connection for this. In operation 812, the terminal may perform device-to-device communication by using the configuration information pre-configured for the V2X application. According to an embodiment of the present disclosure, the preconfigured configuration information may include configuration information for determining whether feedback signaling needs to be performed for a sidelink flow or sidelink packet corresponding to the V2X application. The information preconfigured for determining whether feedback signaling needs to be performed may comprise at least one of [ table 5] above. In operation 812, the terminal may determine whether to transmit feedback signaling of a packet (or a stream) based on configuration information (indicator) allowing determination as to whether to transmit the feedback signaling.

According to an embodiment of the present disclosure, in a case where configuration information on whether to transmit feedback signaling corresponding to the V2X application is acquired through pre-configuration and acquired through signaling from the base station, the terminal may be operated based on the configuration information acquired through the signaling of the base station.

Next, with reference to fig. 9a to 9c, a method for configuring a parameter for determining whether to transmit feedback signaling between terminals performing V2X packet transmission or reception based on direct communication will be described.

Configuration information of feedback signaling proposed in the present disclosure for determining whether to transmit a sidelink stream or a sidelink packet may be exchanged between terminals through signaling. The configuration information for determining whether to transmit the feedback signaling may be transmitted by the transmitting terminal to the receiving terminal. The configuration information may be sent by the group leader terminal to the group member terminals. The configuration information transmitted or received between the terminals may include at least one of the parameters shown in [ table 6] or [ table 7 ]. Based on the methods of fig. 6a to 8b, the determination as to whether to send feedback signaling may be performed by the terminal or the base station or according to preconfigured information.

The signaling between the terminals for transmitting or receiving the configuration information may include at least one of the following signaling.

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

(2) PC5 MAC signaling sent between terminals (e.g., side link MAC CE)

(3) PC5 PHY signaling (e.g., PSCCH or sidelink control information) sent between terminals

In another embodiment, a terminal performing direct communication may acquire feedback signaling transmission information without separate signaling between terminals. According to an embodiment of the present disclosure, regarding a sidelink Logical Channel Identification (LCID) corresponding to a SLRB of a sidelink flow or a sidelink packet, a sidelink LCID in which feedback signaling is transmittable and a sidelink LCID in which feedback signaling is not transmittable may be preconfigured. For example, SL LCID nos. 4 to 10 may be configured as side link LCIDs in which feedback signaling is to be transmitted, and SL LCID nos. 11 to 20 may be configured as side link LCIDs in which feedback signaling is not transmitted. The transmitting terminal and the receiving terminal may determine whether to transmit the feedback signaling based on the LCID information of the SLRB. According to an embodiment of the present disclosure, regarding a hybrid automatic repeat request (HARQ) process ID corresponding to a SLRB of a sidelink flow or a sidelink packet, a sidelink HARQ process ID in which feedback signaling may be transmitted and a sidelink HARQ process ID in which feedback signaling may not be transmitted may be preconfigured.

The information in table 6 may be included in the above-described PC5 RRC signaling or PC5 MAC signaling and then transmitted.

[ Table 6]

The information in table [7] may be included in a Physical Sidelink Control Channel (PSCCH) or Sidelink Control Information (SCI) and then transmitted.

[ Table 7]

Referring to fig. 9a, in operation 901, a UE 1900 may acquire configuration information on whether to transmit feedback signaling of a sidelink flow or a sidelink packet corresponding to a unicast-based direct communication. Operation 901 may refer to the embodiments of fig. 6 a-8 b.

In operation 902, the UE 1900 may transmit AS configuration or SLRB configuration information of a sidelink flow or sidelink packet to the UE 2950, and the information may include configuration information on whether to transmit feedback signaling according to an embodiment of the present disclosure. The information transmitted in operation 902 may include table 6 above. In operation 902, when the receiving terminal transmits feedback signaling, feedback configuration information usable by the receiving terminal may be transmitted together. The signaling performed in operation 902 corresponds to at least one of PC5 RRC unicast signaling or multicast signaling. In operation 903, the UE 2950 may send a configuration complete message in response to the AS configuration or the SLRB configuration of the sidelink flow or sidelink packet.

Referring to fig. 9b, in operation 911, the UE 1900 may acquire configuration information on whether to transmit feedback signaling of a sidelink stream or a sidelink packet corresponding to the unicast-based direct communication. Operation 911 may refer to the embodiments of fig. 6 a-8 c. In operation 912, the UE 1900 may transmit AS configuration or SLRB configuration information of the sidelink flow or sidelink packet to the UE 2950, and the information may include configuration information on whether to transmit feedback signaling according to an embodiment of the present disclosure. The information transmitted in operation 912 may include the above [ table 6 ]. In operation 912, when the receiving terminal transmits feedback signaling, feedback configuration information usable by the receiving terminal may be transmitted together. The signaling performed in operation 912 corresponds to at least one of PC5 RRC broadcast signaling, unicast signaling, or multicast signaling.

According to an embodiment of the present disclosure, the case of configuring whether to send feedback signaling in PC5 MAC signaling may operate similarly to the case shown in fig. 9a or fig. 9 b. PC5 MAC signaling may be used instead of PC5 RRC signaling.

Referring to fig. 9c, in operation 921, the UE 1900 may acquire configuration information on whether to transmit feedback signaling of a sidelink flow or a sidelink packet corresponding to the unicast-based direct communication. Operation 921 may refer to the embodiments of fig. 6 a-8 b. In operation 922, the UE 1900 may transmit SCI information of the sidelink flow or sidelink packet to the UE 2950, and the information may include configuration information on whether to transmit feedback signaling according to an embodiment of the present disclosure. The information transmitted in operation 922 may include the above [ table 7 ].

For example, the information indicating whether feedback signaling is transmitted in the PSCCH SCI may be represented by a HARQ feedback enable indicator.

(feedback signaling to be sent if a packet is not successfully received may be configured for a particular application or a particular type of presentation, however, the disclosure is described under the assumption that if a packet is successfully received, an ACK is sent, and if a packet is not successfully received, a NAK is sent.)

If the HARQ feedback enable indicator is configured to 1, the receiving terminal may recognize transmission of feedback signaling indicating a packet or stream corresponding to the SCI and then transmit feedback of the packet or stream. If the HARQ feedback enable indicator is configured to 0, the receiving terminal may recognize that non-transmission of feedback signaling indicating a packet or stream corresponding to the SCI is indicated, and may then not transmit feedback of the packet or stream.

As another example, information indicating whether feedback signaling is transmitted in the PSCCH SCI may be represented by PQI _ R or PQI _ L. The PSCCH SCI includes at least one of PQI _ R or PQI _ L.

Upon receiving an SCI including a PQI-R or a PQI-L, the receiving terminal may apply a reliability threshold to the PQI-R for a packet or flow corresponding to the SCI, apply a delay threshold to the PQI-L, and determine whether to transmit feedback signaling, based on the conditions of [ table 2] above.

Next, with reference to fig. 10a or 10b, operations of the transmission terminal and the reception terminal according to an embodiment of the present disclosure will be described.

Referring to fig. 10a, when a packet is delivered from a higher layer of a transmission terminal in operation 1001, the transmission terminal may transmit the packet to a reception terminal in operation 1002. In operation 1003, the transmission terminal may determine whether to transmit the feedback signaling of the packet according to the methods of fig. 6a to 9 c. If the packet is a packet in which the feedback signaling is transmittable according to the determination of operation 1003, the transmission terminal may monitor the feedback channel in operation 1004. If the packet is a packet not transmitting feedback signaling according to the determination of operation 1003, the transmission terminal may proceed to operation 1001.

Referring to fig. 10b, the receiving terminal may receive a packet from the transmitting terminal in operation 1011. In operation 1012, the receiving terminal may determine whether the packet is subjected to transmission of feedback signaling according to the method of fig. 6a to 9 c. If the packet is subjected to transmission of feedback signaling according to the determination of operation 1012, the receiving terminal may transmit feedback in a feedback channel in operation 1013. If the packet is not subject to transmission of feedback signaling according to the determination of operation 1012, the receiving terminal may proceed to operation 1011.

Next, with reference to fig. 11a to 11c, the exchange of signals between a terminal and a base station for processing feedback signaling transmission resources according to an embodiment of the present disclosure will be described.

Referring to fig. 11a, in operation 1101, the terminal may determine whether a sidelink packet or flow is subject to transmission of feedback signaling. If transmission of feedback signaling is required, the terminal may request a sidelink feedback resource required for transmission of feedback signaling from the base station in operation 1102. In operation 1103, the base station may allocate a sidelink feedback resource to the terminal.

Referring to fig. 11b, in operation 1111, the base station may allocate a sidelink data resource and a sidelink feedback resource to the terminal. The base station may allocate resources (grouping and feedback) to be used for sidelink unicast or sidelink multicast. In operation 1112, the terminal may determine whether the sidelink flow or sidelink packet is subject to transmission of feedback signaling. If it is determined that the feedback signaling needs to be transmitted, the terminal may transmit the feedback signaling by using the side link feedback resource allocated by the base station in operation 1111 in operation 1113.

Referring to fig. 11c, in operation 1121, the base station may allocate a sidelink data resource pool and a sidelink feedback resource pool to the terminal. The resource pool may correspond to a resource pool (grouping and feedback) to be used in sidelink unicast or sidelink multicast. In operation 1122, the terminal may determine whether the sidelink flow or sidelink packet is subject to transmission of feedback signaling. If it is determined that the feedback signaling needs to be transmitted, in operation 1123, the terminal may request the base station to allocate resources required for transmitting side-link feedback in the resource pool allocated in operation 1121. In operation 1124, the base station may allocate resources required for transmitting the side link feedback by the terminal.

The method of fig. 6a to 11c may be used as an embodiment of handling whether the feedback signaling is sent for V2X packets sent or received through unicast or multicast based device-to-device communication. In case of multicast, if there is no PC5 RRC unicast connection between terminals, after configuring the PC5 RRC unicast connection, configuration information for determining whether to transmit feedback signaling according to an embodiment of the present disclosure may be processed.

Next, according to various embodiments of the present disclosure, a method for configuring a parameter for determining an application of an RLC Acknowledged Mode (AM) or an application of an RLC Unacknowledged Mode (UM) in V2X packet transmission or reception through device-to-device communication will be described.

When RLC AM mode is applied, ARQ may be used to improve the reliability of packet transmission. RLC AM mode may be applied to V2X applications where reliability is more important than delay. The RLC UM mode may be applied to V2X applications where delay is more important than reliability.

As in the embodiments of fig. 6a to 9c, the parameter for determining to apply the RLC AM mode or apply the RLC UM mode in the direct communication may be acquired through at least one configuration information among RRC dedicated signaling, V2X SIB signaling, and pre-configuration. The configuration information may be transmitted through PC5 signaling between terminals (e.g., PC5 RRC bearer configuration) or Uu RRC signaling between a terminal and a base station (e.g., RRC reconfiguration for SL bearer configuration). Further, this method may also be applied, which pre-configures LCID in SL LCID of SLRB corresponding to a sidelink flow or a sidelink packet to apply RLC AM mode and pre-configures LCID to apply RLC UM mode. For example, SL LCID No. 4 through SL LCID No. 10 may be configured for RLC AM mode applications. For example, SL LCID No. 11 to SL LCID No. 20 may be configured for the application of the RLC UM mode.

In addition to the feedback signaling method, the HARQ repetition method of retransmitting the packet without feedback may be applied to correspond to the reliability requirement value or the delay requirement value of the side link packet or flow. The combination of the HARQ repetition method and the feedback signaling method may correspond to one of the following combinations. The terminal or base station may determine which combination to use based on radio conditions and service criteria of sidelink packets or flows.

1. Disabling HARQ repetition if HARQ feedback is disabled

2. Enabling HARQ repetition if HARQ feedback is disabled

3. Disabling HARQ repetition if HARQ feedback is enabled

4. Enabling HARQ repetition if HARQ feedback is enabled

In the case where the HARQ repetition method is applied to the sidelink unicast, the transmitting terminal may determine HARQ repetition, mark whether to perform repetition in SCI information, and transmit the SCI information, and the receiving terminal may determine whether to perform HARQ repetition with reference to the SCI information.

As shown in numeral 4, in the case where the HARQ repetition method and the feedback signaling method are used together, as an embodiment, feedback signaling may be transmitted for each packet (including a packet initially transmitted and a packet transmitted by repetition). That is, an ACK or NACK may be transmitted for each packet.

In another embodiment, the feedback signaling may be configured to send a NACK when reception of all packets (including the initially sent packet and the packet sent by repetition) fails. The feedback signaling may be configured to send an ACK upon receipt of at least one packet (including an initially sent packet and a packet sent by repetition).

Based on the various embodiments of fig. 6a to 11c, the operation of the terminal and the base station in the case where the determination to enable or disable HARQ feedback for SL streams or SL packets is performed by the terminal or by the base station has been discussed. Based on fig. 12 to 14, the operation of the terminal and the base station will be described according to which entity (terminal or base station) will determine to enable/disable HARQ feedback and which entity (terminal or base station) will allocate the SL grant according to the determination to enable/disable HARQ feedback.

According to various embodiments of the present disclosure, HARQ feedback may be applied to each SL resource pool. For example, if HARQ feedback is configured for SL resource pool a, a terminal that has received a packet transmitted using resources in pool a may transmit HARQ feedback for the packet. As another example, if disabled HARQ feedback is configured for SL resource pool B, a terminal that has received a packet transmitted using resources in pool B may not transmit HARQ feedback for the packet. Therefore, in the case where it is determined that an SL stream or SL packet requiring HARQ feedback is required, it is necessary to operate the terminal and the base station to select resources from an SL resource pool in which HARQ feedback is configured. In the case of an SL stream or SL packet in which HARQ feedback is determined not to be required, it is necessary to operate the terminal and the base station to select resources from a SL resource pool in which HARQ feedback is configured to be disabled.

Fig. 12 is a diagram illustrating a signal flow in which a terminal transmits HARQ feedback assistance information to a base station according to one embodiment of the present disclosure.

The embodiment of fig. 12 may be used in a case where the base station allocates the SL grant to the terminal in the RRC _ CONNECTED state or the terminal allocates the SL grant itself according to the instruction of the base station. In the case where the base station allocates the SL grant to the terminal (mode 1), the base station is required to select a SL resource pool related to whether to transmit HARQ feedback based on the information of the terminal and allocate the SL grant from the corresponding pool. For this purpose, the base station is required to acquire information on whether to transmit HARQ feedback from the terminal. In the case where the terminal allocates the SL grant itself according to the instruction of the base station (mode 2), the base station is required to select the SL resource pool related to whether or not to transmit the HARQ feedback based on the information of the terminal and to instruct the terminal to allocate the SL grant from the corresponding pool itself. For this purpose, the base station is required to acquire information on whether to transmit HARQ feedback from the terminal.

Referring to fig. 12, a terminal 1200 may transmit a message including information on whether to transmit HARQ feedback to a base station 1250 in operation 1201. The message used in operation 1201 may be replaced with a sildelinkueinformation message or a UEAssistanceInformation message. The sildelinkueinformation message or UEAssistanceInformation message transmitted by the terminal to the base station may include at least one or a combination of pieces of information in the following [ table 8 ].

[ Table 8]

In operation 1202, the base station may receive information as shown in [ table 8] from the terminal, and may determine to be configured to transmit or receive HARQ feedback according to the SL HARQ feedback enable indication information. The base station may decide to assign the SL grant directly to the terminal (mode 1). If configured to send or receive HARQ feedback, the base station may allocate a SL grant to the terminal from a SL resource pool in which HARQ feedback enable is configured. The SL license is at least one of a dynamic SL license, a configuration license type 1, a configuration license type 2, and an SPS SL license. In operation 1203, the base station may transmit a message including information on configuration of the SL license to the terminal. The configuration of the SL grant transmitted by the base station to the terminal may include at least one of the information in the following [ table 9] or a combination of a plurality of pieces of information.

[ Table 9]

The above [ table 9] may be transmitted in a case where the base station directly allocates the SL grant.

In another embodiment, the base station may determine that HARQ feedback does not need to be transmitted or received according to SL HARQ feedback enable indication information in [ table 8] received from the terminal in operation 1202. The base station may decide to assign the SL grant directly to the terminal (mode 1). The base station may allocate a SL grant to the terminal from a SL resource pool in which HARQ feedback disabling is configured. The SL license is at least one of a dynamic SL license, a configuration license type 1, a configuration license type 2, and an SPS SL license. In operation 1203, the base station may transmit a message including information on configuration of the SL license to the terminal. The configuration of the SL license may include at least one of the information in table 9 above or a combination of a plurality of pieces of information.

As yet another example, in operation 1202, the base station may decide to instruct the terminal to assign the SL grant itself (mode 2). If it is configured to transmit or receive HARQ feedback based on the HARQ feedback enable indication in [ table 8] above, the base station may provide information on the SL resource pool in which HARQ feedback enable is configured to the terminal. In operation 1203, the base station may transmit a message to the terminal, the message including SL license configuration information indicating a mode 2 in which the terminal itself allocates the SL license. The configuration of the SL license may include at least one of the information in the following [ table 10] or a combination of a plurality of pieces of information.

[ Table 10]

In another embodiment, the base station may determine that HARQ feedback does not need to be transmitted or received according to SL HARQ feedback enable indication information in [ table 8] received from the terminal in operation 1202. The base station may indicate mode 2 so that the terminal itself assigns the SL grant. The base station may provide information to the terminal about the SL resource pool in which the disable HARQ feedback is configured. In operation 1203, the base station may transmit a message to the terminal, the message including SL license configuration information indicating a mode 2 in which the terminal itself allocates the SL license. The configuration of the SL license may include at least one of the information in table 10 above or a combination of a plurality of pieces of information.

In operation 1204, based on the information (table 9 or table 10) on the configuration of the SL grant received from the base station, the SL grant may be allocated to the terminal by the base station, or the terminal may allocate the SL grant itself from the SL resource pool according to the instruction of the base station. If an SL grant (mode 1) is allocated by the base station in operation 1204, the SL grant may be selected by the base station from a SL resource pool corresponding to the HARQ feedback enabled. As another example, if the SL grant is allocated by the base station in operation 1204 (mode 1), the SL grant may be selected by the base station from a SL resource pool corresponding to HARQ feedback disable. As still another embodiment, if the terminal allocates the SL grant itself according to the instruction of the base station in operation 1204 (mode 2), the terminal may select the SL grant from the SL resource pool corresponding to the HARQ feedback enabled instructed by the base station. As still another embodiment, if the terminal allocates the SL grant itself according to the instruction of the base station in operation 1204 (mode 2), the terminal may select the SL grant from the SL resource pool corresponding to the HARQ feedback disable instructed by the base station.

The terminal may transmit a packet in the SL grant allocated by the base station and/or the SL grant allocated by the terminal itself, and may perform an operation of monitoring reception of HARQ feedback from the receiving terminal (in case of HARQ feedback enabled) or may perform an operation of not monitoring reception of HARQ feedback (in case of HARQ feedback disabled) according to the HARQ feedback enable indication of operation 1201.

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

The embodiment OF fig. 13 may be used in a case where a terminal in RRC _ IDLE, RRC _ INACTIVE or OUT _ OF _ COVERAGE state allocates SL grant itself.

Referring to fig. 13, in operation 1301, a terminal in an RRC _ IDLE, RRC _ INACTIVE, or OUT _ OF _ COVERAGE state may determine whether a sidelink resource needs to be allocated in order to transmit a packet. If resource allocation is required, the terminal may determine whether HARQ feedback for an SL stream or an SL packet corresponding to the packet is required in operation 1302. Whether HARQ feedback is required may be determined according to at least one or a combination of [ table 1] to [ table 7] above.

If it is determined in operation 1303 that HARQ feedback for a packet is required, the terminal may allocate an SL grant from a sidelink resource pool in which HARQ feedback enable is configured in operation 1304. In operation 1306, the terminal may transmit a packet by using the SL grant. Alternatively, if it is determined in operation 1303 that HARQ feedback for a packet is not required, the terminal may allocate an SL grant from a sidelink resource pool in which HARQ feedback disabling is configured in operation 1305, and may proceed to operation 1306 to transmit a packet by using the SL grant. The SL license assigned by the terminal in fig. 13 may correspond to at least one of a dynamic SL license, a configuration license type 1, a configuration license type 2, or an SPS SL license.

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

Referring to fig. 14, in operation 1401, the terminal may determine whether to transmit HARQ feedback for an SL stream or an SL packet. In operation 1402, the terminal may determine whether the terminal is in an RRC _ CONNECTED state. When the terminal is in RRC _ CONNECTED state, the terminal may request the base station to allocate SL grant.

When it is determined that the terminal is in the RRC _ CONNECTED state according to the determination of operation 1402, the terminal may transmit terminal assistance information for SL grant to the base station in operation 1403. The terminal assistance information may be included in a sildelinkueinformation message or a UEAssistanceInformation message. The terminal assistance information transmitted in operation 1403 may include information on whether to transmit the HARQ feedback based on the determination of operation 1401. That is, SL grant allocation request information for SL streams or SL packets in which HARQ feedback needs to be transmitted or SL grant allocation request information for SL streams or SL packets in which HARQ feedback does not need to be transmitted may be transmitted from the terminal to the base station.

In operation 1404, the terminal may receive a SL resource pool configuration from the base station. The SL resource pool configuration information may be transmitted through an RRC _ ConnectionReconfiguration message or an RRC _ Reconfiguration message transmitted to the terminal by the base station. In operation 1405, the terminal may determine whether the base station indicates a mode (mode 1) in which the base station allocates the SL grant according to the SL resource pool configuration. If it is determined that the base station is instructed to operate in a mode (mode 1) in which the SL grant is allocated, the terminal may receive the SL grant from the base station in operation 1406. The base station may allocate the SL grant from a sidelink resource pool corresponding to HARQ feedback enabled based on the information on whether to transmit the HARQ feedback transmitted by the terminal in operation 1403, or may allocate the SL grant from a sidelink resource pool corresponding to HARQ feedback disabled.

In operation 1407, the terminal may transmit a packet of the SL stream or the SL packet by using the SL grant. In operation 1407, the terminal may process the packet according to the information related to the HARQ feedback enable or HARQ feedback disable of the packet determined in operation 1401. For example, if HARQ feedback enable is configured, the terminal may wait for HARQ feedback of a packet transmitted in the SL grant. For example, if HARQ feedback disable is configured, the terminal may not wait (monitor) for HARQ feedback for packets sent in the SL grant.

In operation 1405, the terminal may determine whether the base station indicates a mode (mode 2) in which the terminal itself allocates the SL grant according to the SL resource pool configuration. If it is determined that the base station has indicated a mode (mode 2) in which the terminal itself allocates the SL grant, the terminal may itself allocate the SL grant from the sidelink resource pool configuration indicated for allocating the SL grant in operation 1404 in operation 1408. The sidelink resource pool indicated by the base station may correspond to a sidelink resource pool corresponding to HARQ feedback enable or may correspond to a sidelink resource pool corresponding to HARQ feedback disable, based on the information on whether to transmit HARQ feedback transmitted by the terminal in operation 1403. The terminal may allocate the 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 information related to HARQ feedback enabled or HARQ feedback disabled of the packet determined in operation 1401.

In operation 1409, the terminal may transmit a packet corresponding to the SL stream or the SL packet by using the SL grant allocated in operation 1408. For example, if HARQ feedback enable is configured, the terminal may wait for HARQ feedback of a packet transmitted in the SL grant. For example, if HARQ feedback disable is configured, the terminal may not wait for HARQ feedback for packets sent in the SL grant.

If the terminal is not in the RRC _ CONNECTED state, as determined in operation 1402, the terminal may be in at least one OF an RRC _ IDLE, RRC _ INACTIVE, or OUT _ OF _ COVERAGE state. The terminal may allocate SL grants from the SL resource pool itself if the terminal is in at least one OF RRC _ IDLE, RRC _ INACTIVE or OUT _ OF _ COVERAGE states.

In operation 1410, the terminal may determine whether HARQ feedback is enabled based on the determination information regarding whether HARQ feedback needs to be transmitted for the SL stream or the SL packet, which is determined in operation 1401. If it is determined in operation 1410 that HARQ feedback enable is configured for the SL stream or the SL packet, the terminal may allocate a SL grant from a sidelink resource pool corresponding to the HARQ feedback enable in operation 1411. In operation 1412, the terminal may transmit a packet corresponding to the SL stream or the SL packet by using the SL grant allocated in operation 1411. Further, in operation 1412, the terminal may wait for HARQ feedback for the packet transmitted in the SL grant. Alternatively, if it is determined in operation 1410 that HARQ feedback disable is configured for the SL stream or the SL packet, the terminal may allocate a SL grant from a sidelink resource pool corresponding to the HARQ feedback disable in operation 1413.

In operation 1414, the terminal may transmit a packet corresponding to the SL stream or the SL packet by using the SL grant allocated in operation 1413. Further, the terminal may not wait for HARQ feedback of a packet transmitted in the SL grant.

According to an embodiment of the present disclosure, an operation of the terminal performing a logical channel priority handling procedure on a logical channel corresponding to a HARQ feedback enabled SL stream or SL packet or a logical channel corresponding to a HARQ feedback disabled SL stream or SL packet is as follows.

The terminal may select a destination identifier having a logical channel that satisfies the following conditions. The destination identifier may correspond to at least one of unicast, multicast, and broadcast. The terminal may select one destination identifier of a logical channel having the highest transmission priority among logical channels satisfying the following conditions. The terminal may select a random destination if there are one or more destination identifiers having logical channels that satisfy the condition and have the highest transmission priority.

(1) Logical channels have data to transmit

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

For each logical channel, the initial value of the SBj value is configured to be 0. At each point in time in which the logical channel priority handling procedure is performed, the SBj value is increased (sPBR X T). sPBR corresponds to the side chain priority bit rate. T is the time elapsed from the point in time where the previous SBj value was calculated to the current point. If the value of SBj becomes greater than the sidelink bucket size (sPBR X sBSD), the value of SBj will be configured to the sidelink bucket size. Bsd corresponds to the side chain bucket size duration. The value of SBj may be operated to prevent starvation, where the logical channel is not given a transmission opportunity and therefore it cannot send an SL stream or SL packet for the logical channel.

(3) If the SL license allows the configuration license type 1, the configuration license type 1 is configured for the corresponding logical channel.

(4) If the SL grant allows HARQ feedback, HARQ feedback enable is configured for the corresponding logical channel.

The terminal may select a logical channel satisfying the following conditions for the selected destination identifier.

(1) Logical channels have data to transmit

(2) If the SL license allows the configuration license type 1, the configuration license type 1 is configured for the corresponding logical channel.

(3) If the SL grant allows HARQ feedback, HARQ feedback enable is configured for the corresponding logical channel.

The terminal may transmit the SL stream or SL packet corresponding to the selected logical channel through the SL grant. In an embodiment, if HARQ feedback enabled is configured for the selected logical channel, the transmission may be performed through HARQ feedback enabled SL grant. If HARQ feedback enable is configured and a plurality of logical channels are selected, SL streams or SL packets corresponding to the plurality of logical channels may be transmitted through the HARQ feedback enabled SL grant. In an embodiment, if HARQ feedback disable is configured for the selected logical channel, transmission may be performed with SL grant with HARQ feedback disabled. If HARQ feedback disable is configured and multiple logical channels are selected, SL streams or SL packets corresponding to the multiple logical channels may be transmitted with SL grants of HARQ feedback disable.

According to an embodiment of the present disclosure, if it is determined that HARQ feedback disable or HARQ feedback enable is configured for a logical channel corresponding to an SL stream or an SL packet, but a HARQ feedback disable resource pool is configured and a HARQ feedback enable resource pool is not configured, the terminal may ignore HARQ feedback disable or HARQ feedback enable configuration configured for a logical channel corresponding to an SL stream or an SL packet and may operate according to HARQ feedback disable configuration configured in the resource pool. That is, it is determined that HARQ feedback disable is configured for the resource pool, and thus the terminal may perform an operation in a case where HARQ feedback disable is configured for a logical channel of an SL stream or an SL packet.

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

When the methods are implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured for execution by one or more processors within the electronic device. At least one program may include instructions that cause an electronic device to perform methods according to various embodiments of the present disclosure as defined by the appended claims and/or disclosed herein.

Programs (software modules or software) may be stored in non-volatile memory including random access memory and flash memory, Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disk storage, compact disk-ROM (CD-ROM), Digital Versatile Disks (DVD) or other types of optical storage, or magnetic cassettes. Alternatively, any combination of some or all of them may form a memory in which the program is stored. Further, a plurality of such memories may be included in the electronic device.

Further, these programs may be stored in an attachable storage device that can access the electronic device through a communication network such as the internet, an intranet, a Local Area Network (LAN), a wide LAN (wlan), and a Storage Area Network (SAN), or a combination thereof. Such storage devices may access the electronic device via an external port. Further, a separate storage device on the communication network may access the portable electronic device.

In the above detailed embodiments of the present disclosure, elements included in the present disclosure are expressed in the singular or plural according to the presented detailed embodiments. However, the singular or plural is appropriately selected for the presented situation for convenience of description, and the present disclosure is not limited to the elements expressed in the singular or plural. Thus, elements expressed in the plural may also include a single element, or elements expressed in the singular may also include a plurality of elements.

Although specific embodiments have been described in the detailed description of the present disclosure, various modifications and changes may be made thereto without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be defined as limited to the embodiments, but should be defined by the appended claims and equivalents thereof.

Claims

1. A method for a first terminal in a wireless communication system, the method comprising:

sending data to the second terminal through the side link;

identifying whether hybrid automatic repeat request (HARQ) feedback for the sidelink is enabled; and

HARQ feedback information on the data is monitored with HARQ feedback for the sidelink enabled.

2. The method of claim 1, wherein whether HARQ feedback for the sidelink is enabled is identified based on configuration information indicating whether HARQ feedback is enabled, and

The configuration information is configured by the base station.

3. The method of claim 2:

Wherein, when the first terminal is in a radio resource control (RRC) connected state, the configuration information is configured by an RRC reconfiguration message,

wherein, when the first terminal is in an RRC inactive state or an RRC idle state, the configuration information is configured by system information, and

Wherein, when the first terminal is outside the coverage of the base station, the configuration information is pre-configured.

4. The method of claim 3, further comprising:

when the first terminal is in the RRC connection state, sending side link terminal information to the base station, where the side link terminal information requests the configuration of transmission resources of the side link,

wherein the RRC reconfiguration message is received to correspond to the transmission of the sidelink terminal information.

5. The method of claim 4, wherein the RRC reconfiguration message includes resource pool configuration information for the sidelink, and

The HARQ information about the data is sent based on the resource pool configuration information.

6. The method of claim 4, wherein the sidelink terminal information includes destination identification information of a sidelink stream, information about a type of presentation performed with the second terminal, and information about a sidelink stream. At least one of quality of service information.

7. The method of claim 1, further comprising sending sidelink control information to the second terminal, the sidelink control information scheduling the data,

The side link control information indicates whether to enable the HARQ feedback.

8. A first terminal in a wireless communication system, the first terminal comprising:

transceiver; and

a controller configured to:

controlling the transceiver to send data to the second terminal through the side link;

The transceiver is controlled to monitor HARQ feedback information on the data in a case where HARQ feedback for the sidelink is enabled.

9. The first terminal of claim 8, wherein the controller is further configured to identify whether to enable HARQ for the sidelink based on configuration information configured by a base station and indicating whether to enable HARQ feedback feedback.

10. The first terminal of claim 9,

11. The first terminal of claim 10,

Wherein, when the first terminal is in the RRC connection state, the controller is further configured to control the transceiver to send side link terminal information to the base station, the side link terminal information requesting the configuration of the transmission resources of the side link, and

12. The first terminal of claim 10,

wherein the RRC reconfiguration message includes resource pool configuration information of the side link, and

wherein the controller is further configured to control the transceiver to send HARQ information about the data based on the resource pool configuration information.

13. The first terminal of claim 10, wherein the sidelink terminal information includes destination identification information of a sidelink stream, information on a type of presentation performed with the second terminal, and sidelink At least one of the quality of service information of the flow.

14. The first terminal of claim 8, wherein the controller is further configured to control the transceiver to transmit sidelink control information to the second terminal, the sidelink control information scheduling the data ,as well as