WO2020096280A1 - Method for performing sidelink feedback procedure in nr v2x system, and device for same - Google Patents

Abstract

The present invention can provide a method for a terminal to transmit feedback information in an NR V2X system. Here, the method for transmitting feedback information may include: a step for a first terminal to establish a session with a second terminal on the basis of at least one among a unicast and a groupcast; a step for the first terminal to transmit data to the second terminal through a resource set on the basis of the established session; and a step for the first terminal to receive feedback information from the second terminal on the basis of the data. Here, when a plurality of resource sets are set in the first terminal and the second terminal, the second terminal may transmit the feedback information about data on the plurality of resource sets to the first terminal through one specific resource set.

Description

Method and apparatus for performing sidelink feedback procedure in NR V2X system

The present invention relates to a method and apparatus for performing a Sidelink (SL) feedback procedure in a New Radio (NR) V2X (Vehicle To Everything) system. The present invention relates to a method and apparatus for transmitting and receiving sidelink feedback information in an NR V2X system.

The International Telecommunication Union (ITU) is developing the International Mobile Telecommunication (IMT) framework and standards, and is currently in the process of discussing 5G (5G) communication through a program called "IMT for 2020 and beyond." .

In order to meet the requirements presented by "IMT for 2020 and beyond", the 3rd Generation Partnership Project (3GPP) New Radio (NR) system takes into account various scenarios, service requirements, potential system compatibility, etc., and time-frequency It is being discussed in the direction of supporting various numerology of resource unit standards.

In addition, V2X communication means a communication method of exchanging or sharing information such as traffic conditions while communicating with road infrastructure and other vehicles while driving. V2X is a vehicle-to-vehicle (V2V), which means long term evolution (LTE) -based communication between vehicles, and a vehicle-to-pedestrian (V2P), which means LTE-based communication between a vehicle and a terminal carried by an individual. And a vehicle-to-infrastructure / network (V2I / N), which means LTE-based communication between the roadside unit / network. Here, a roadside unit (RSU) may be a transport infrastructure entity implemented by a base station or a fixed terminal. For example, it may be an entity that transmits a speed notification to the vehicle.

The present invention can provide a method and apparatus for performing a sidelink feedback procedure in an NR V2X system.

The present invention can provide a method and apparatus for transmitting and receiving sidelink feedback information in an NR V2X system.

The present invention can provide a method and apparatus for transmitting a Physical Sidelink Feedback Channel (PSFCH) channel for each resource set when a plurality of resource sets exist in the NR V2X sidelink.

The present invention can provide a method and apparatus for indicating a resource set for transmitting a PSFCH channel for each resource set when a plurality of resource sets exist in the NR V2X sidelink.

The present invention can provide a method for a terminal to transmit feedback information in an NR V2X system. At this time, the method for transmitting the feedback information is a step in which the first terminal establishes a session based on at least one of a unicast and a groupcast with the second terminal, and the second terminal returns to the second terminal based on the established session. The method may include transmitting data through a resource set and receiving feedback information based on the data from the second terminal by the first terminal. In this case, when a plurality of resource sets are set in the first terminal and the second terminal, the second terminal may transmit feedback information for data of the plurality of resource sets to the first terminal through one specific resource set.

According to the present disclosure, it is possible to provide a method and apparatus for performing a sidelink feedback procedure in an NR V2X system.

According to the present disclosure, it is possible to provide a method and apparatus for transmitting and receiving sidelink feedback information in an NR V2X system.

According to the present disclosure, it is possible to provide a method and apparatus for transmitting a PSFCH channel for each resource set when a plurality of resource sets exist in the NR V2X sidelink.

According to the present disclosure, it is possible to provide a method and apparatus for indicating a resource set for transmitting a PSFCH channel for each resource set when a plurality of resource sets exist in the NR V2X sidelink.

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

1 is a diagram showing a frame structure for downlink / uplink transmission to which the present disclosure can be applied.

2 is a diagram showing a resource grid and a resource block to which the present disclosure can be applied.

3 is a diagram showing a system architecture according to an embodiment of the present invention.

4 is a diagram illustrating a scenario in which NR V2X sidelink communication is performed in a 3GPP network according to an embodiment of the present invention.

5 is a diagram for a method of transmitting a PSFCH in consideration of a plurality of resource sets according to an embodiment of the present invention.

6 is a diagram for a method of transmitting a PSFCH in consideration of a plurality of resource sets according to an embodiment of the present invention.

7 is a diagram for a method of transmitting a PSFCH in consideration of a plurality of resource sets according to an embodiment of the present invention.

8 is a diagram for a method of instructing PSFCH transmission in consideration of a plurality of resource sets according to an embodiment of the present invention.

9 is a view showing a method of transmitting a PSFCH in consideration of different neurology according to an embodiment of the present invention.

10 is a view showing a method of transmitting a PSFCH in consideration of different neurology according to an embodiment of the present invention.

11 is a flowchart illustrating a method of transmitting a PSFCH according to an embodiment of the present invention.

12 is a flowchart illustrating a method for transmitting a PSFCH according to an embodiment of the present invention.

13 is a view showing the configuration of a base station apparatus and a terminal apparatus according to an embodiment of the present invention.

The present invention provides a method for a terminal to transmit feedback information in a NR (New Radio) V2X (Vehicle to everything) system, wherein the first terminal establishes a session based on at least one of the second terminal, unicast and groupcast. Establishing a step, the first terminal transmitting data through a resource set to the second terminal based on the established session, and the first terminal receiving feedback information based on the data from the second terminal When the plurality of resource sets are set in the first terminal and the second terminal, the second terminal may receive feedback information on data of the plurality of resource sets through one specific resource set. It is possible to provide a method for transmitting feedback information, which is transmitted to one terminal.

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present disclosure pertains can easily carry out the embodiments. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein.

In describing the embodiments of the present disclosure, when it is determined that a detailed description of known configurations or functions may obscure the subject matter of the present disclosure, detailed description thereof will be omitted. In the drawings, parts irrelevant to the description of the present disclosure are omitted, and similar reference numerals are used for similar parts.

In the present disclosure, when a component is said to be "connected", "coupled" or "connected" with another component, this is not only a direct connection relationship, but also an indirect connection relationship in which another component exists in the middle. It may also include. Also, when a component is said to "include" or "have" another component, this means that other components may be further included, not specifically excluded, unless otherwise stated. .

In the present disclosure, terms such as first and second are used only for the purpose of distinguishing one component from other components, and do not limit the order or importance of components, etc., unless otherwise specified. Accordingly, within the scope of the present disclosure, the first component in one embodiment may be referred to as a second component in another embodiment, and likewise the second component in one embodiment may be the first component in another embodiment It can also be called.

In the present disclosure, the components that are distinguished from each other are for clarifying each feature, and the components are not necessarily separated. That is, a plurality of components may be integrated to be composed of one hardware or software unit, or one component may be distributed to be composed of a plurality of hardware or software units. Accordingly, such integrated or distributed embodiments are included within the scope of the present disclosure, unless otherwise stated.

In the present disclosure, components described in various embodiments are not necessarily essential components, and some may be optional components. Accordingly, an embodiment composed of a subset of components described in one embodiment is also included in the scope of the present disclosure. Also, embodiments including other elements in addition to the elements described in various embodiments are included in the scope of the present disclosure.

In addition, this specification is described for a wireless communication network, the work performed in the wireless communication network is performed in the process of controlling the network and transmitting data in a system (for example, a base station) that is in charge of the wireless communication network, or the wireless The operation can be performed at the terminal coupled to the network.

That is, it is obvious that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station can be performed by a base station or other network nodes other than the base station. The term 'base station (BS)' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), and an access point (AP). In addition, 'terminal (terminal)' is to be replaced by terms such as User Equipment (UE), Mobile Station (MS), Mobile Subscriber Station (MSS), Subscriber Station (SS), non-AP STA, etc. Can be.

In the present disclosure, transmitting or receiving a channel includes transmitting or receiving information or a signal through the corresponding channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through the data channel.

In the following description, the term NR system is used for the purpose of distinguishing a system to which various examples of the present disclosure are applied from an existing system, but the scope of the present disclosure is not limited by these terms. In addition, although the term NR system is used herein as an example of a wireless communication system capable of supporting various subcarrier spacing (SCS), the term NR system itself is a wireless communication system supporting a plurality of SCSs. It is not limited.

1 is a diagram illustrating an NR frame structure and a numerology according to an embodiment of the present invention.

In NR, the basic unit of time domain is

Can be At this time,

ego,

Can be In addition,

May be a constant for a multiple relationship between an NR time unit and an LTE time unit. In reference time unit, in LTE

,

And

Can be defined.

Frame structure

Referring to FIG. 1, a time structure of a frame for downlink / uplink (DL / UL) transmission is

Can have At this time, one frame

It consists of 10 subframes corresponding to time. The number of consecutive OFDM symbols per subframe is

Can be Further, each frame is divided into two half frames, and the half frame may be composed of 0 to 4 subframes and 5 to 9 subframes. At this time, half frame 1 (half frame 1) may be composed of 0 to 4 subframes, and half frame 2 (half frame 2) may be composed of 5 to 9 subframes.

At this time, the transmission timing of the uplink transmission frame i is determined based on Equation 1 below based on the downlink reception timing at the terminal.

Equation 1 below

May be a TA offset value that occurs due to a duplex mode difference. Basically, in FDD (Frequency Division Duplex)

Has 0, but in TDD (Time Division Duplex), considering the margin for DL-UL switching time,

It can be defined as a fixed value.

[Equation 1]

2 is a diagram illustrating a resource grid and a resource block.

Referring to FIG. 2, resource elements in a resource grid may be indexed according to each subcarrier spacing. At this time, one resource grid may be generated for each antenna port and for each subcarrier spacing. Uplink and downlink transmission and reception may be performed based on a corresponding resource grid.

One resource block is composed of 12 resource elements on the frequency domain. As shown in Equation 2 below, an index for one resource block per 12 resource elements (

). The index for the resource block can be utilized within a specific frequency band or system bandwidth.

[Equation 2]

Numerologies

Numerology can be variously configured to satisfy various services and requirements of the NR system. In this case, referring to Table 1 below, numerology may be defined based on subcarrier spacing (SCS), CP length, and the number of OFDM symbols per slot used in an orthogonal frequency division multiplexing (OFDM) system. . The above-described values may be provided to the terminal through higher layer parameters DL-BWP-mu and DL-BWP-cp (DL) and UL-BWP-mu and UL-BWP-cp (UL).

In addition, as an example, in Table 1 below

When 2 is a subcarrier spacing of 60 kHz, normal CP and extended CP may be applied, and only normal CP may be applied in other bands.

[Table 1]

At this time, the normal slot (Normal slot) may be defined as a basic time unit used to basically transmit one data and control information in the NR system. The length of the normal slot may basically consist of the number of 14 OFDM symbols. Also, unlike the slot, the subframe has an absolute time length corresponding to 1 ms in the NR system and can be used as a reference time for the length of another time interval. At this time, for coexistence or compatibility (backword compatibility) of the LTE and NR systems, a time period such as a subframe of LTE may be required in the NR standard.

For example, in LTE, data may be transmitted based on a transmission time interval (TTI) that is a unit time, and the TTI may be configured in one or more subframe units. At this time, even in LTE, one subframe may be set to 1 ms, and 14 OFDM symbols (or 12 OFDM symbols) may be included.

Also, a non-slot can be defined in the NR. The non-slot may mean a slot having a number as small as at least one symbol than a normal slot. For example, in the case of providing a low latency, such as an Ultra-Reliable and Low Latency Communications (URLLC) service, the latency may be reduced through a nonslot having a smaller number of symbols than a normal slot. In this case, the number of OFDM symbols included in the non-slot may be determined in consideration of the frequency range. For example, a non-slot of 1 OFDM symbol length may be considered in a frequency range of 6 GHz or more. As another example, the number of OFDM symbols defining a non-slot may include at least two OFDM symbols. In this case, the range of the number of OFDM symbols included in the non-slot may be configured as the length of the mini-slot up to the length of the normal slot-1. However, as a non-slot standard, the number of OFDM symbols may be limited to 2, 4 or 7 symbols, but is not limited to the above-described embodiment.

Also, as an example, in the unlicensed band below 6 GHz

Subcarrier spacing corresponding to 1 and 2 is used, and in the unlicensed band above 6 GHz

Subcarrier spacing corresponding to 3 and 4 may be used. In this case, as an example,

If is 4, it can be used only for SSB (Synchronization Siganl Block), which will be described later, and is not limited to the above-described embodiment.

In addition, Table 2 shows each subcarrier spacing setting for the normal CP.

Number of OFDM symbols per slot

Indicates. Table 2 shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe according to each subcarrier spacing value as provided in Table 1. At this time, Table 2 shows the above-mentioned values based on a normal slot having 14 OFDM symbols.

[Table 2]

In addition, as described above,

When is 2, the extended CP may be applied when the subcarrier spacing is 60 kHz. Table 3 is an extended CP

Number of OFDM symbols per slot

Can represent each value based on 12 normal slots. In this case, referring to Table 3, in the case of an extended CP conforming to 60 kHz subcarrier spacing, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe may be indicated.

[Table 3]

Next, the structure of the SSB / PBCH (Physical Broadcast Channel) in the NR system and the initial cell access procedure in the NR system will be described.

At this time, the NR base station (i.e. gNB) may periodically transmit signals and channels as shown in Table 4 below to the UEs in order to allow initial cell selection of UEs in the cell (i.e. UEs).

[Table 4]

For example, the SS / PBCH block may be the aforementioned SSB. At this time, even in the NR system, in order for the UE to perform the initial radio access, it may be necessary to receive a broadcast channel that transmits a synchronization signal and important system information transmitted from the radio access system. To this end, the terminal can check the reception sensitivity of the synchronization signal (Synchronization Signal) in order to find the optimal cell in the best channel environment. The terminal may perform frequency / time synchronization and cell identification to perform initial access to an optimal channel among one or more channels in a specific frequency band operated based on the checked reception sensitivity. The UE can check the boundary of the OFDM symbol timing through the above-described operation, and then can start decoding the PBCH in the same SSB.

At this time, the terminal may perform PBCH decoding by receiving a PBCH DMRS (Demodulation Reference Signal). Also, the terminal may acquire 3 LSB bit information among SSB index information bits through PBCH DMRS. Subsequently, the UE can obtain information included in the PBCH payload by performing PBCH decoding. Thereafter, the terminal may perform the decoding procedure of SIB 1 using the information obtained through the PBCH.

For example, in an NR system, a UE may receive Remaining System Information (RMSI) as a system information not transmitted on a PBCH through a broadcast signal or channel. In addition, the UE may receive other system information (OSI) and paging channels as additional system information through a broadcast signal or a channel.

Thereafter, the UE may perform access to the base station through a RACH (Random Access Channel) procedure, and then perform mobility management.

In addition, as an example, when the terminal receives the SSB, there is a need to set the SSB composition (SSB Composition) and the SS Burst Set composition (SS Burst Set Composition).

NR V2X service

In relation to the V2X service, the existing V2X service (e.g. LTE Rel-14 V2X) was able to support a set of basic requirements for the V2X services. At this time, the requirements were basically designed with sufficient consideration of the road safety service. Accordingly, V2X user equipments (UEs) can exchange self-state information through a sidelink, and exchange the above-described information with infrastructure nodes and / or pedestrians. It became possible.

On the other hand, in a more evolved service as a V2X service (eg LTE Rel-15), carrier aggregation in a sidelink, high order modulation, latency reduction, transmission diversity (Tx) diversity) and new features were introduced considering the feasibility of sTTI. Based on the above, coexistence (same resource pool) with V2X UEs was required, and the above-described services were provided based on LTE.

For example, in consideration of use cases for supporting a new V2X service as System Aspect (SA) 1, technical characteristics may be categorized based on four categories as shown in Table 5 below. In this case, in Table 5 below, vehicle driving (Vehicles Platooning) may be a technique in which a plurality of vehicles dynamically form a group and operate similarly. In addition, extended sensors may be a technique of collecting and exchanging data obtained from a sensor or video image. In addition, advanced driving may be a technology in which a vehicle is driven based on full automation or semi-automation. In addition, remote driving may be a technology for providing a technology and an application for remote control of a vehicle, and more detailed information on the above may be as shown in Table 5 below.

[Table 5]

In addition, the above-described SA1 is an eV2X (enhanced V2X) support technology for supporting a new V2X service, both LTE and NR can be considered. For example, the NR V2X system may be a first V2X system. Also, the LTE V2X system may be a second V2X system. That is, the NR V2X system and the LTE V2X system may be different V2X systems. In the following description, related content is described based on a method for satisfying low delay and high reliability required in the NR sidelink based on the NR V2X system. However, the same or similar configuration may be extended and applied to the LTE V2X system, and is not limited to the following embodiments. That is, the LTE V2X system may be applied to parts that can be interoperable, and is not limited to the following embodiments. At this time, as an example, NR V2X capability (capability) may not necessarily be limited to support only V2X services, and which V2X RaT is used may be selected.

NR Sidelink

For the above-mentioned NR V2X service, an NR sidelink may be used. In this case, as an example, the NR sidelink frequency (NR Sidelink Frequency) may consider FR1 (i.e. up to 52.6 GHz), which is a frequency of 6 GHz or less and FR2 of a frequency exceeding 6 GH. In addition, as an example, as for the NR sidelink frequency, both unlicensed ITS bands and licensed bands may be considered. That is, as described above, a common design method for supporting each frequency band may be required. To this end, an NR sidelink design considering an NR system may be required. For example, even in the case of omni-directional Tx / Rx that is not actually beam-based in the same way as NR-standard design, an NR sidelink design capable of basically supporting beam-based transmission and reception may be required, and is not limited to the above. .

Also, as an example, a physical channel for NR V2X sidelink may be established. For example, NR PSSCH (Physical Sidelink Shared Channel) may be a data channel for the NR sidelink as a physical channel. Further, as an example, NR PSCCH (Physical Sidelink Control Channel) may be a control channel for NR sidelink as a physical channel. At this time, scheduling information for the data channel of the NR sidelink and other control information may be transmitted through the NR PSCCH. For example, Sidelink Control Information (SCI) is a format in which fields for control information related to scheduling of an NR sidelink data channel are defined, and control information transmitted through the NR PSCCH can be transmitted based on the SCI format.

In addition, as an example, NR PSFCH (Physical Sidelink Feedback Channel) may be defined. In this case, the NR PSFCH may be an NR HARQ feedback channel as a physical channel. At this time, HARQ-ACK feedback information, channel status information (CSI), and other information corresponding to the NR sidelink data channel may be transmitted through the NR PSFCH. More specifically, SFCI (Sidelink Feedback Control Information) including feedback information may be transmitted through the NR PSFCH channel. At this time, SFCI is HARQ-ACK, CQI (Channel Quality Information), PMI (Precoding Matrix Indicator), RI (Rank Indicator), RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), pathgain / pathloss, SRI ( Scheduling Request Indicator), CRI (Contention Resolution Identity), interference condition, may include at least one or more of vehicle motion information, it is not limited to the above-described embodiment.

Also, as an example, NR SLSS (Sidelink Synchronization Signal) / PSBCH (Physical Sidelink Broadcast Channel) block is defined as a synchronous and broadcast channel block in which an NR SL sync signal and a broadcast channel are transmitted in one continuous time in the physical layer. Can be. At this time, the NR SLSS / PSBCH block may be periodically transmitted based on a set of one or more block indices to support beam-based transmission on the NR frequency band. In addition, the synchronization signal is composed of a PSSS (Primary Sidelink Synchronization Signal) and a SSSS (Secondary Sidelink Synchronization Signal), and a sequence for the signal may be generated based on at least one SLSSID value. At this time, the PSBCH can be transmitted with SLSS for the purpose of delivering system information required to perform V2X SL communication. For example, the SLSS / PSBCH block may be periodically transmitted in the form of a set of SLSS / PSBCH block indices to support beam-based transmission, as described above.

In addition, Table 6 below may be each term applied in the following invention, but is not limited to the above-described embodiment.

[Table 6]

NR side link design

The following describes the NR V2X sidelink design method that satisfies the requirements for the above-mentioned advanced V2X (i.e. eV2X) services.

More specifically, the synchronization procedure and method required in forming a radio link for the NR sidelink will be described in detail. For example, as described above, in the NR sidelink design, FR1 and FR2 (ie up to 52.6 GHz) and unlicensed and unlicensed ITS bands and licensed bands (ITS) as NR sidelink frequencies are operated by the NR system. And ranges. In addition, as an example, the availability of the LTE (NG-eNB) / NR Uu link, which is the 3GPP NG-RAN network of Table 6 described above, may be considered in the NR sidelink design.

In addition, as an example, a design for eV2X synchronous information transmission and signal transmission and reception to satisfy higher requirements from the above-mentioned advanced V2X services may be considered. At this time, the frequency for the NR V2X sidelink communication may be further considered at least one or more of the elements shown in Table 7 below based on technologies required in the following new system different from the existing system (e.g. LTE). That is, it is necessary to satisfy the new V2X service requirements by applying the NR V2X side link based on NR radio access technology, particularly uplink transmission related technologies, as shown in Table 7 below.

In addition, other factors may be considered in consideration of the new system as well as Table 7 below, and are not limited to the above-described embodiment.

[Table 7]

In addition, as an example, the physical channel, signal, basic slot structure and physical resource of the NR V2X sidelink may be as shown in Table 8 below, as described above.

[Table 8]

In addition, as an example, FIG. 3 may be a basic network architecture configuration considering NR V2X sidelink.

For example, referring to FIG. 3, 5GC (5G Core NW) nodes 310-1, 310-2 and NG-RAN nodes 320-1, 320-2, 330-1, 330-2 The NG interface can be set in between. In addition, an Xn interface may be set between NG-RAN nodes 320-1, 320-2, 330-1, and 330-2. At this time, gNB (NR UP / CP protocol, 320-1, 320-2) and NG-eNB (E-UTRA UP / CP protocol, 330-1, 330-2) constituting the NG-RAN in the above-described architecture are used. Centrally, the nodes can be interconnected through an Xn interface. In addition, as described above, it may be connected to the 5GC through the NG interface. In this case, as an example, in the above-described architecture, both the LTE sidelink terminal and the NR sidelink terminal may be controlled by NG-RAN (i.e.LTE Uu and NR Uu) based on gNB and NG-eNB. Therefore, when the NR sidelink terminal transmits synchronization information, it can receive synchronization information from LTE Uu or NR Uu link and transmit NR sidelink synchronization information (eg SL Synchronization Signal / SL Physical broadcast Channel) based on the information. It is not limited to the above-described embodiment. That is, the NR sidelink terminal can acquire synchronization information not only through the NR Uu link but also through the LTE Uu link.

Meanwhile, in connection with V2X side link communication, V2X side link terminals may perform V2X side link communication. However, certain conditions need to be satisfied in order for the V2X sidelink terminals to start communication, and the conditions for this may be as shown in Table 9 below. That is, the V2X sidelink terminal can perform V2X sidelink communication in an RRC idle state, an inactive state, or a connected mode. In addition, V2X sidelink terminals performing V2X sidelink communication need to be registered in a selected cell on a frequency used or belong to the same PLMN. In addition, when the V2X sidelink terminal is OOC on the frequency for V2X sidelink communication, V2X sidelink communication can be performed only when V2X sidelink communication can be performed based on pre-configuration information. .

[Table 9]

At this time, as described above, sidelink synchronization information may be required to start V2X sidelink communication. Therefore, the terminal needs to transmit sidelink synchronization information. However, the transmitting terminal (Sidelink Tx UE) may receive a setting for transmitting sidelink synchronization information before transmitting the corresponding synchronization information. In this case, as an example, the transmitting terminal may receive a setting for transmitting sidelink synchronization information based on the system information message or RRC reset message (for RRC CONNECTED UE) broadcast from the NG-RAN nodes described above. Also, as an example, when the NR V2X sidelink terminal (hereinafter referred to as a terminal) does not exist in the NG-RAN network, sidelink synchronization information may be transmitted based on preset information, as described above.

Meanwhile, FIG. 4 may be an example of a scenario in which NR V2X sidelink communication is performed in a 3GPP network based on the above. At this time, NR V2X sidelink communication may be performed on a 3GPP network (hereinafter, NG-RAN), and the presence of a GNSS signal may be additionally considered.

More specifically, referring to FIG. 4, each NR V2X sidelink terminal may be an IC or OOC based on EUTRA NG-eNB 410. In addition, it may be an IC or OOC based on the gNB 420. In addition, it may be an IC or OOC based on the GNSS 430. At this time, in consideration of the above-described situation, the NR V2X sidelink terminals can select the source of the synchronization reference based on the location and capability of the terminal. In addition, as an example, in addition to the scenario shown in FIG. 6, scenarios shown in Table 10 below may be considered, and are not limited to the above-described embodiment.

Table 10

Meanwhile, in the following, NR SCS is any one of SCS values for NR DL SS / PBCH, SCS values for NR data / control channel (BWP), or reference SCS values defined / set for comparison of NR V2X SCS values. Can be. As another example, NR SCS is defined for comparison of SCS values for NR V2X SLSS / PSBCH, SCS values for NR V2X BWP or resource pool (resource pool (data / control channel)), or NR V2X SCS values. / It may be one of the set reference SCS values, and is not limited to the above-described embodiment. In addition, as an example, for the 5.9 GHz ITS spectrum, a 30 kHz SCS value may be set and used as a default value. However, this is only one example and is not limited to the above-described embodiment.

When performing NR V2X Sidelink communication, data transmission may be performed based on unicast / groupcast. In this case, as an example, unicast transmission may mean that one terminal transmits a message to another terminal. That is, it may mean one-to-one transmission. In addition, broadcast transmission may be a method of transmitting a message to all terminals regardless of whether a receiving terminal supports a service. That is, one terminal can transmit a message regardless of whether a plurality of receiving terminals support the service. Meanwhile, the groupcast transmission method may be a method of sending a message to a plurality of terminals belonging to the group.

At this time, as an example, the above-described activation of unicast, groupcast or broadcast data transmission and session connection may be determined at a higher layer. That is, the physical layer of the V2X sidelink terminal (hereinafter referred to as V2X SL terminal) may operate based on the instruction determined by the upper layer, but is not limited to the above-described embodiment.

In addition, as an example, the V2X SL terminal may perform a corresponding transmission / reception after a session for transmitting a corresponding unicast or groupcast data is formed. When the V2X SL terminal transmits / receives based on the above-described session, the physical layer parameter information for data transmission corresponding to unicast or groupcast may be previously known in the physical layer of the V2X SL terminal. As an example, the V2X SL terminal may recognize by receiving the above-described information in advance from the base station. As another example, the above-described information may be information preset to the V2X SL terminal. In this case, as an example, the parameter information may include at least one ID value as shown in Table 11 below. More specifically, destination group ID and source ID information may be included in the parameter information in relation to the group cast. In addition, a destination ID and a source ID may be included in parameter information in connection with unicast. As another example, the HARQ process ID may also be included in parameter information, which will be described later.

[Table 11]

In this case, as an example, unicast or multicast data transmission and reception may be applied when a small number of V2X terminals exist around the transmitting V2X terminal and the session is maintained stably. In addition, when the session is unstable or there are many changes to neighboring V2X terminals, data transmission may be mainly performed based on broadcast transmission. However, the above-described content is only one example and is not limited thereto.

In addition, as an example, as described above, unicast or groupcast transmission and reception may be determined at an application layer stage as an upper layer. In this case, as an example, data that can be allocated to transmission / reception made in the application layer may not be directly mapped to a radio layer. However, as an example, in the case of the above-described unicast or groupcast transmission and reception, a certain mapping relationship or connection establishment procedure may be required to perform data transmission and reception on the radio layer, but is not limited thereto.

In addition, as an example, in the case of unicast data transmission and reception, there is a need to establish a session with each other by performing a procedure of discovering whether the corresponding transmission / reception terminals are around each other (eg, discovery procedure), and session establishment is performed based on various methods. Can be. At this time, session establishment between the terminals may be performed with the help of the base station. The base station collects location information of the terminals and can determine whether terminals capable of transmitting and receiving unicast or groupcast data are adjacent to each other. In this case, as an example, the base station may determine whether the terminals are adjacent based on the threshold, and the determination for the threshold may be any value. When it is determined that the terminals in the cell are adjacent to each other, the base station initializes the discovery procedure, and the terminals can perform the discovery procedure to discover each other based on the initialization procedure. In addition, the base station may design a new discovery channel to periodically transmit and receive the corresponding channel to determine whether a V2X SL terminal exists in the vicinity. In addition, the base station can transmit and receive the discovery message (discovery message) on the V2X data channel (V2X data channel) to determine the presence of the neighboring terminal, it is not limited to the above-described embodiment.

That is, session establishment for unicast or groupcast data transmission and reception may be completed based on the above-described procedures.

Thereafter, the upper layer can inform the physical layer of the session establishment information and perform physical layer operations such as HARQ-ACK, CSI, and link adaptation.

Hereinafter, a case in which a PSFCH (Physical Sidelink Feedback Channel) channel is used for HARQ-ACK feedback transmission among the above-described operations will be described.

The following describes a physical resource selection method for transmitting a PSFCH (Physical Sidelink Feedback Channel) channel for HARQ-ACK feedback transmission during the above-described operation.

In addition, as an example, in the following description, a related content is mainly described with respect to a PSFCH channel as a channel for transmitting feedback information. However, as an example, the PSFCH (feedback channel) for delivering feedback information may be defined as a new physical channel, but may be defined as a feedback channel for delivering feedback information by recycling a processing chain for an existing control channel (eg PSCCH). . That is, the feedback information may be transmitted through a newly defined channel (e.g. PSFCH) or may be transmitted through a channel that reuses the existing control channel as much as possible.

However, for convenience of description, the following description is based on the term PSFCH channel. Therefore, in the following embodiment, “transferred over the PSFCH channel” may be replaced with “a new physical channel is not defined and feedback information is included in the physical channel by recycling an existing control channel and transmitted”. Further, as an example, some feedback information is transmitted through the PSFCH channel, and some feedback information may be included in the control channel and transmitted, and is not limited to the above-described embodiment. However, in the following description, PSFCH is mainly described for convenience of description.

Further, as an example, when establishing a session for unicast and / or groupcast transmission in the NR sidelink, the session may be performed based on a discovery procedure. More specifically, at least two terminals (discoveree, discoverer) that discover each other through a discovery procedure may store each other's context. Thereafter, the terminals can transmit and receive a message in one unicast or groupcast session based on layer-2 ID (layer-1 ID is used for filtering data packets). In this case, as an example, transmitting and receiving a message based on the above-described session may mean exchanging signaling in a handshake form between two terminals at least when transmitting unicast or groupcast. On the other hand, broadcast may mean that the above-described signaling operation is not necessary, and that the transmission is performed to a plurality of terminals unilaterally.

In this case, as an example, a unicast session may be established based on one source ID and a specific destination ID of another terminal. Also, a groupcast session may be established based on one group specific destination ID. On the other hand, broadcast may be identified by one service (e.g. flow-specific destination ID) as one sidelink session. Therefore, it can be considered that all transmissions are performed within the same session for the same service.

In this case, as an example, the following is based on recognizing at least the layer 1 context between terminals to perform data transmission and reception on the sidelink and connecting one session through one link having one reliable QoS. To describe. At this time, the terminals can perform message exchange based on the established session.

At this time, as an example, the terminal may recognize the presence of neighboring terminals based on the discovery message as described above. When the terminals establish a unicast and / or groupcast session, the terminals may exchange the following information as control information. At this time, as an example, the terminals may exchange control information necessary for feedback transmission on a specific sidelink resource set.

More specifically, the terminals may exchange information on the total number of sidelink resource sets per unicast and / or groupcast session in the session establishment process. (Total number of SL resource sets (eg resource pool, BWP and / or carrier) per a unicast / groupcast session) In this case, as an example, the total number of sidelink resource sets per unicast and / or groupcast session is unicast and / Or It may mean the total number of sidelink carriers per groupcast session. Further, as an example, the total number of sidelink resource sets per unicast and / or groupcast session may be the total number of one or a plurality of sidelink BWPs set for one or a plurality of sidelink carriers. In addition, as an example, the total number of sidelink resource sets per unicast and / or groupcast session may mean the total number of resource pools set in the sidelink BWP as described above. In addition, as an example, information for each resource pool, BWP, or carrier that can be included as one resource (hereinafter, divided into sidelink resource indexes) in the total number of the resource set includes as many as the total number of sidelink resource sets described above. Can be exchanged. For example, when the total number of resource sets is composed of two resource pools, configuration information for each resource pool may be configured. At this time, the configuration information for one resource pool may include at least one or more of allocation information on a specific time / frequency resource and neurology information. In addition, as an example, configuration information for one resource pool may further include other information, and is not limited to the above-described embodiment. Also, as an example, configuration information for BWP and carrier may also be configured for each session described above. You can.

As another example, the total number of sidelink resource sets per unicast and / or groupcast session may mean the total number of resource pools set for one or a plurality of sidelink carriers per unicast and / or groupcast session. .

In addition, as an example, when the UE establishes a session, the UE may exchange sidelink resource index information. (SL resource index (eg SL carrier / BWP / resource pool index) for PSFCH transmission) At this time, as an example, The sidelink resource index information may be sidelink resource index information set for feedback transmission among a plurality of sidelink resource sets.

More specifically, when a plurality of sidelink resource sets refer to a plurality of sidelink carriers, sidelink resource index information corresponding to one or a portion of a plurality of sidelink resource sets configured for feedback transmission may be required. have. At this time, the terminals can exchange the above-described information.

Specifically, when three sidelink carriers are configured for unicast and / or groupcast transmission (eg SL carriers # 0 to 2), feedback information on data generated in each sidelink carrier is transmitted from SL carrier # 0 It can be set as possible, and a specific method will be described later. In this case, as an example, the index information for the above-described operation may be exchanged and set as physical layer parameter information among related terminals in the process of establishing a unicast and / or groupcast session. Alternatively, for example, in the case of unicast and / or groupcast transmission between terminals in a base station scheduling mode or an RRC connected mode, corresponding physical layer parameter information may be set through RRC signaling by the base station. Thereafter, the terminals can exchange parameter information set in the session establishment process, and are not limited to the above-described embodiment.

As another example, the terminals may further exchange information about the number of feedback cell groups. (The number of feedback cell group (eg 1 or 2)) For example, when feedback transmission is performed on one or more resource sets , A group of resource sets associated with each feedback transmission may be defined as a feedback cell group. At this time, the terminals may exchange information about the feedback cell group in the process of establishing a session. In addition, as an example, it may be desirable to limit up to two cell groups for feedback transmission, but is not limited thereto. That is, the terminals can exchange the number information of the feedback cell group during the session establishment process, and are not limited to the above. Hereinafter, specific examples will be described based on the above.

Example

5 is a diagram illustrating a method in which PSFCH is transmitted based on different resources.

Referring to FIG. 5, after one unicast / groupcast session is connected, the transmitting terminal may simultaneously transmit data in a plurality of sidelink resource sets (e.g. resource pool / BWP / carrier). Thereafter, the receiving terminal may transmit feedback information to the transmitting terminal based on the data transmitted to the transmitting terminal. In this case, as an example, the feedback information may be HARQ-ACK, but is not limited thereto. For example, the feedback information may include at least one or more of CQI, PMI, RI, RSRP, RSRQ, path gain / pathloss, SRI, CRI, interference condition, and vehicle motion, and is not limited to the above-described embodiment.

Here, the sidelink resource set may be at least one of a sidelink resource pool (SL resource pool), a sidelink BWP (SL BWP, Bandwidth part) and a sidelink carrier (SL carrier) set for a terminal for sidelink data transmission and reception. have. In addition, the sidelink resource set may be set based on a combination of a sidelink resource pool, sidelink BWP and sidelink carriers. That is, the sidelink resource set means that different frequency resources are used, and is not limited to the above-described embodiment.

In this case, as an example, when performing unicast and / or groupcast V2X communication based on transmission such as HARQ-ACK or CSI feedback, the V2X SL terminal can perform transmission of feedback information associated with each resource set. have. For example, the feedback information may be transmitted through the PSFCH corresponding to each sidelink resource pool. In addition, as an example, feedback information may be transmitted through a PSFCH corresponding to each sidelink BWP. In addition, for example, it may be transmitted through the PSFCH corresponding to each sidelink carrier. That is, the terminal may transmit feedback information through the associated PSFCH in each sidelink resource set regardless of whether the PSFCH transmission resource is determined based on a specific resource set.

In more detail, referring to FIG. 5, the transmitting terminal performs data through resource set 1 (eg SL resource pool, BWP, Carrier # 0) and resource set 2 (eg SL resource pool, BWP, Carrier # 1). / SA (510-1, 510-2) may be transmitted to the receiving terminal. At this time, as an example, each data / SA (510-1, 510-2) may be transmitted in the n-th slot (slot n). At this time, the receiving terminal may transmit feedback information for data / SAs 510-1 and 510-2 of each resource set to the transmitting terminal through the respective PSFCHs 520-1 and 520-2. In this case, PSFCHs 520-1 and 520-2 for each resource set may be set for each resource set.

At this time, the resources for the PSFCH (520-1, 520-2) can be transmitted on a specific time / frequency determined in the same sidelink resource set as the data / SA (510-1, 510-2) is transmitted resource set have. That is, the PSFCHs 520-1 and 520-2 may be transmitted through the same resource set from which the data / SA is transmitted. In this case, as an example, the exact physical resource through which the PSFCH is transmitted may be determined as a specific resource in advance by a predetermined method in the above-described resource set. In addition, as an example, the exact physical resource through which the PSFCH is transmitted may be indicated as a specific resource in the above-described resource set through a separate indication through SCI. That is, the PSFCH is transmitted through the same resource set as the data / SA transmitted resource set, and specific physical resources in the resource set may be set by various methods, and is not limited to the above-described embodiment.

  At this time, as an example, in consideration of the above-described case, when the receiving terminal receives the data / SA from the transmitting terminal, the receiving terminal on the determined specific time / frequency resources in the same sidelink resource set as the resource set that received the data / SA PSFCH transmission can be performed, respectively. However, since a plurality of sidelink data / SA transmission and reception are performed, inefficiency of resource utilization may occur.

As an example, PSFCH transmission having a relatively smaller number of transmission bits than data / SA transmission blocks is performed in all sidelink resource sets configured for unicast and / or groupcast data / SA transmission and reception, resulting in inefficiency for resource utilization. This can happen. In this case, as an example, when the feedback timings for data / SA received from a plurality of sidelink resource sets are the same, inefficiency for resources may be greater. In addition, as an example, when performing PSFCH transmission on all sidelink resource sets configured for unicast and / or groupcast data / SA transmission / reception, it causes potential additional interference and collision issues to other terminals, thereby causing system performance degradation. Can be

As another example, since the power of each PSFCH transmitting important control information is limited, degradation of potential reception performance may occur. In addition, since PSFCHs must be simultaneously transmitted and received on a plurality of resource sets, RF complexity for supporting them may be increased.

At this time, in the present invention, in order to solve the above-described problems, the PSFCH channel can be performed on a specific sidelink resource set based on the same synchronization, and a specific method for this is described. At this time, the performance of the NR V2X system may be improved through the above-mentioned.

 Accordingly, the following describes an efficient PSFCH transmission method for unicast and / or groupcast sessions in which data / SA transmission and reception on a plurality of sidelink resource sets are connected. As an example, the following describes a specific method based on the number of sidelink resource sets through which PSCCH and / or PSSCH are transmitted and the number of sidelink resource sets through which PSFCH can be transmitted can be asymmetric. That is, the number of sidelink resource sets through which PSCCH and / or PSSCH are transmitted may be different from the number of sidelink resource sets through which PSFCH can be transmitted.

For example, unicast data / SA transmission / reception with a plurality of sidelink resource sets may be considered. At this time, when two terminals establish a unicast session, a plurality of sidelink resource sets may be set. At this time, the two terminals may perform unicast data / SA transmission and reception through each of a plurality of set sidelink resource sets. In this case, as an example, the sidelink resource set may refer to a resource area in which data / SA transmission and reception can be performed, and the data / SA may be transmitted and received through a specific time / frequency resource in each resource set. At this time, a specific time / frequency resource in each resource set through which data / SA is transmitted may be set in advance or indicated by signaling. In addition, as an example, when a groupcast session is established, a plurality of sidelink resource sets may be set between terminals in a corresponding group. At this time, UEs in the corresponding group may perform data / SA transmission / reception through each resource set. That is, a plurality of resource sets exist based on unicast and / or multicast between two target terminals, and data / SA transmission and reception may be performed based on this.

Meanwhile, as an example, only when the terminal has the ability to perform communication through a plurality of resource sets, each data / SA can be transmitted through the plurality of resource sets as described above. For example, when a unicast and / or groupcast session is established between terminals capable of communicating through a plurality of resource sets (eg, multi-carrier SL V2X communication capable UE), the transmitting terminal is a plurality of sidelink resource sets, respectively. In unicast and / or groupcast transmission can be performed. At this time, the receiving terminal may transmit each PSFCH for each transmission of a plurality of sidelink resource sets through one specific sidelink resource set. That is, the receiving terminal can transmit the PSFCH only in a specific sidelink resource set among a plurality of sidelink resource sets. In this case, as an example, the exact time / frequency resource in which each PSFCH is transmitted in a specific sidelink resource set may be preset or indicated by signaling, and is not limited to the above-described embodiment. That is, unlike data / SA being transmitted through a plurality of sidelink resource sets, the PSFCH can be transmitted through one specific sidelink resource set.

In more detail, referring to FIG. 6, in the n-th slot, the transmitting terminal is configured through resource set 1 (eg SL resource pool, BWP, Carrier # 0) and resource set 2 (eg SL resource pool, BWP, Carrier # 1). Data / SAs 610-1 and 610-2 may be transmitted to the receiving terminal, respectively. At this time, the receiving terminal may transmit feedback information for each data / SA 610-1 and 610-2 through the PSFCH. In this case, as an example, feedback information for each data / SA 610-1, 610-2 may be transmitted in one specific sidelink resource set. In this case, as an example, feedback information may be transmitted through the PSFCH 620-1 set in the specific sidelink resource set described above. In this case, as an example, the above-described specific sidelink resource set may be sidelink resource set 1. That is, the PSFCH 620-1 may be transmitted in a sidelink resource set as a specific sidelink resource set. In this case, as an example, the PSFCH 620-1 may be transmitted through a specific time / frequency resource within the sidelink resource set 1, as described above. At this time, as an example, referring to FIG. 6, the transmitting terminal may transmit the respective data / SAs 610-1 and 610-2 to the receiving terminal through sidelink resource set 1 and sidelink resource set 2, respectively. In this case, as an example, the receiving terminal is a specific sidelink resource set, and provides feedback information for each data / SA 610-1, 610-2 through one PSFCH 620-1 resource in resource set 1 as well. Can transmit. That is, when the transmitting terminal transmits each data / SA (610-1, 610-2) to the receiving terminal through each sidelink resource set in the same slot (slot n), the receiving terminal is the same slot (slot n At +1), PSFCH 620-1 for each data / SA 610-1 and 610-2 may be transmitted through a specific resource within one specific sidelink resource set.

In addition, as an example, when the transmitting terminal transmits each data / SA (610-1, 610-2) to the receiving terminal in different slots (eg slot n and slot n-1), the receiving terminal is the respective data / PSFCH 620-1 transmission for SAs 610-1 and 610-2 can be performed through one resource in a specific resource set in the same slot (slot n + 1), and is limited to the above-described embodiment Does not work. That is, feedback information for data / SA corresponding to different times may also be transmitted through specific resources in one specific resource set, and is not limited to the above-described embodiment.

Further, as an example, when the transmitting terminal transmits data / SA 610-3 through resource set 1 as one resource set in the m-th slot, the receiving terminal performs PSFCH through resource set 1 in the m + 1th slot. (620-2) Transmission can be performed. In addition, when the transmitting terminal transmits data / SA 610-4 through resource set 2 as one resource set in the k-th slot, the receiving terminal performs PSFCH (620-) through resource set 1 in the k + 1th slot. 3) Transmission can be performed. That is, the resource set through which the PSFCH is transmitted may be determined as a specific resource set irrespective of the resource set through which the data / SA is transmitted, and the PSFCH may be transmitted through resources in the specific resource set.

Also, as an example, referring to FIG. 7, in the n-th slot, the transmitting terminal performs resource set 1 (eg SL resource pool, BWP, Carrier # 0) and resource set 2 (eg SL resource pool, BWP, Carrier # 1). Through the data / SA (710-1, 710-2) can be transmitted to the receiving terminal at the same time. In this case, a set of resources for which PSFCH transmission is performed may be indicated in the SCI for each data / SA 710-1 and 710-2. In this case, as an example, the feedback information for each data / SA 710-1 and 710-2 is based on the SCI indication, and the PSFCH 720-720 is configured through a resource set in one resource set (eg resource set 1). 1) Transmission can be performed.

In addition, as an example, in the m-th slot, the transmitting terminal performs data / SA (respectively) through resource set 1 (eg SL resource pool, BWP, Carrier # 0) and resource set 2 (eg SL resource pool, BWP, Carrier # 1), respectively. 710-3 and 710-4) may be simultaneously transmitted to the receiving terminal. At this time, a set of resources for which PSCFH transmission is performed may be indicated in the SCI for each data / SA 710-3 and 710-4. In this case, as an example, the feedback information for each data / SA 710-3 and 710-4 is a resource set in one resource set (eg resource set 2) based on the SCI indication, and the PSFCH 720-2 It can be transmitted through. Also, as an example, data / SA 710-3 indicates resource set 2 for a feedback channel, and data / SA 710-4 feedbacks from the same resource set from which data / SA 710-4 was received. It is possible to instruct to perform channel transmission. Based on this, as described above, feedback information for each data / SA 710-3 and 710-4 may be transmitted through the PSFCH 720-2 set in one resource set (eg resource set 2). have.

In addition, as an example, in the k-th slot, the transmitting terminal performs data / SA (respectively) through resource set 1 (eg SL resource pool, BWP, Carrier # 0) and resource set 2 (eg SL resource pool, BWP, Carrier # 1). 710-5 and 710-6) may be simultaneously transmitted to the receiving terminal. At this time, a set of resources for which PSCFH transmission is performed may be indicated in the SCI for each data / SA 710-3 and 710-4. In this case, as an example, the feedback information for each data / SA 710-3 and 710-4 is a specific resource in each resource set in which data / SA is transmitted based on the SCI indication, and each PSFCH 720-3 , 720-4), and is not limited to the above-described embodiment.

As another example, a case in which a plurality of resource sets are set based on one unicast session to two terminals may be considered. Alternatively, a case in which a plurality of resource sets are set based on a plurality of unicast sessions may be considered. Alternatively, a case in which a plurality of resource sets are set based on unicast and groupcast sessions on two terminals may be considered.

In this case, as an example, when a plurality of resource sets are set based on one unicast session to two terminals, the SCI may further include a bit of whether the PSFCH is indicated through the resource set of the corresponding session. At this time, if the corresponding bit is a value of “0”, the PSFCH can be transmitted through one resource set of the corresponding session, and is based on a specific sidelink resource index determined during the session or a sidelink resource index for which current data / SA transmission is received. Thus, the PSFCH can be transmitted on a specific resource in the above-described resource set.

As another example, when one or more unicast and / or groupcast sessions are set in the terminal and one or more resource sets are set for each session, if feedback or channel estimation information for data received through a plurality of sessions is established The feedback transmission may be set or directed to be transmitted by being limited to a specific session. For example, when one terminal has a plurality of terminals and one or more unicast sessions and one or more groupcast sessions, one or a part of sidelink resources (eg resource pool) existing in one specific groupcast session , BWP, carrier) can transmit feedback for one or more unicast and groupcast. As described above, the specific groupcast may be determined in advance at the time of session establishment or may be indicated through RRC signaling of the base station, DCI signaling or SCI signaling of the terminal. The receiving terminal may perform feedback transmission through a session for transmitting the indicated feedback and a specific side link resource in the indicated session. However, since the sessions established between different terminals are not related to each other, feedback transmission method performed mainly between one or more sessions established in the same terminals or groups can be mainly considered. have.

As another example, a resource through which the PSFCH is transmitted may be indicated as a specific resource during a session establishment process. For example, when two terminals establish a unicast session based on a plurality of resource sets, the resource through which the PSFCH is transmitted may be indicated in the process of establishing the unicast session. That is, after the session is established, the resource through which the PSFCH is transmitted may be fixed as a specific resource.

As another example, a resource through which PSFCH is transmitted may be indicated based on a dynamic manner through SCI. For example, 1-bit SCI may be defined. At this time, when the 1-bit field value in the SCI is “0”, the resource on which the PSFCH is transmitted may be determined based on the SL resource index at which the current data transmission is received. In addition, when the 1-bit field value in the SCI is “1”, the resource on which the PSFCH is transmitted may be determined based on a specific SL resource index determined by the associated terminals during the establishment of a unicast or groupcast session. That is, the transmitting terminal can dynamically indicate the resource on which the PSFCH is transmitted in consideration of the channel environment.

As another example, the resource through which the PSFCH is transmitted may be indicated based on another method. More specifically, a plurality of resources set in the corresponding session may be indicated through SCI. As an example, a case where the SCI is 2 bits may be considered. At this time, when the SCI is the first value (e.g. '00'), the resource on which the PSFCH is transmitted may be determined based on the SL resource index at which the current data transmission used in the corresponding session is received. In addition, when the SCI is the second value (e.g. '01'), the resource on which the PSFCH is transmitted may be determined based on the first sidelink resource index used in the corresponding session. In addition, when the SCI is the third value (e.g. '10'), the resource on which the PSFCH is transmitted may be determined based on the second sidelink resource index used in the corresponding session. In addition, when the SCI is the fourth value (e.g. '00'), the resource on which the PSFCH is transmitted may be determined based on the third sidelink resource index used in the corresponding session.

However, the SCI bit may not be limited to the above. For example, the number of SCI bits may be larger considering the number of sidelink resources, and is not limited to the above-described embodiment.

At this time, as an example, when a unicast and / or groupcast session is established among terminals capable of setting a plurality of resource sets, the terminals are assigned a specific sidelink resource indicated through the PSFCH transmission presence indicator in the SCI field provided in the PSCCH. PSFCH transmission can be performed. In addition, UEs may not perform PSFCH transmission on a sidelink resource that is not indicated through the PSFCH transmission presence indicator in the SCI field provided in the PSCCH. Therefore, the receiving terminal can utilize the resource for other sidelink transmissions.

In addition, referring to FIG. 8 as an example, as described above, information related to a session may be exchanged between associated terminals during the establishment of a unicast and / or groupcast session.

It may be determined which sidelink resource set (e.g. resource pool / BWP / carrier) is used for data / SA transmission / reception between terminals. In addition, it may be determined which sidelink resource set (e.g. resource pool / BWP / carrier) is used between the terminals to transmit feedback information.

In this case, as an example, a case where a plurality of carriers exist as a resource set, or when a plurality of resource pools exist for each carrier, or when a plurality of BWPs are set may be considered.

Further, as an example, Table 12 below is a diagram showing an example of PSFCH transmission switching based on FIG. 8. However, Table 12 is only one example for convenience of description, and is not limited to the following examples.

Table 12

In this case, as an example, based on Table 12, four terminals may be associated with each of the two unicast sessions (unicast # 0, unicast # 1).

At this time, as an example, in the case of unicast # 0, UE 1 and UE 2 may perform data / SA transmission on SL carrier # 0 and SL carrier # 1. Also, PSFCH transmission and reception may be performed on SL carrier # 0. For example, based on the above, the plurality of resource sets may be SL carrier # 0 and SL carrier # 1, and the specific resource set for PSFCH transmission and reception may be SL carrier # 0. In addition, as an example, in the case of unicast # 1, UE 3 and UE 4 may perform data / SA transmission on SL carrier # 0 and SL carrier # 1. In addition, PSFCH transmission and reception may be performed on SL carrier # 1. For example, based on the above, the plurality of resource sets may be SL carrier # 0 and SL carrier # 1, and the specific resource set for PSFCH transmission and reception may be SL carrier # 1. In this case, as an example, a terminal transmitting data / SA may indicate a sidelink resource for PSFCH transmission to a data / SA receiving terminal through a sidelink resource indicator for PSFCH transmission. At this time, the sidelink resource indicator does not indicate the exact resource on which the PSFCH transmission is performed, but may indicate the sidelink resource set in which the sidelink resource on which the PSFCH transmission is possible exists. That is, a specific resource set for PSFCH transmission may be indicated. Accordingly, PSFCH transmission may be performed through a specific sidelink resource determined in a corresponding sidelink carrier after a specific sidelink carrier is indicated as a specific resource set.

Further, as an example, referring to Table 13, in the case of unicast # 0, UE 1 and UE 2 can perform data / SA transmission through Resource pool # 0 and Resource pool # 1 in SL carrier # 0, respectively. . In addition, PSFCH transmission and reception can be performed in Resource pool # 0. For example, based on the above, the plurality of resource sets may be Resource pool # 0 and Resource pool # 1, and the specific resource set for PSFCH transmission and reception may be Resource pool # 0. Further, as an example, in the case of unicast # 1, UE 3 and UE 4 can perform data / SA transmission in Resource pool # 0 and Resource pool # 1 in SL carrier # 0. In addition, PSFCH transmission and reception can be performed in Resource pool # 0. For example, based on the above, a plurality of resource sets may be Resource pool # 0 and Resource pool # 1, and a specific resource set for PSCH transmission and reception may be Resource pool # 0. That is, compared to Table 12, a plurality of resource sets may be in units of resource pools. At this time, the set of resources through which the PSFCH is transmitted may also be in resource pool units.

In this case, as an example, a terminal transmitting data / SA may indicate a sidelink resource for PSFCH transmission to a data / SA receiving terminal through a sidelink resource indicator for PSFCH transmission. At this time, the sidelink resource indicator does not indicate the exact resource on which the PSFCH transmission is performed, but may indicate the sidelink resource set in which the sidelink resource on which the PSFCH transmission is possible exists. That is, a specific resource set for PSFCH transmission may be indicated. Accordingly, PSFCH transmission may be performed through a specific sidelink resource determined in a corresponding sidelink resource pool after a specific resource pool is indicated as a specific resource set.

[Table 13]

In this case, as an example, the sidelink resource performing PSFCH transmission and reception (PSFCH Tx / Rx SL) based on the above may be determined for each unicast and / or groupcast session, and the method 1 or method 2 in Table 14 It can be determined on the basis of.

More specifically, as an example, a resource for PSFCH transmission in a resource set for PSFCH transmission may be determined during session establishment. That is, a resource for PSFCH transmission may be determined based on a semi-static method.

As another example, a terminal transmitting data / SA may indicate PSFCH transmission on a specific sidelink resource (e.g. SL resource pool / BWP / carrier) through an SCI field among possible sidelink resource sets. That is, only a set of resources for PSFCH transmission is determined, and specific resources for PSFCH transmission may be indicated in a dynamic manner through SCI.

As a more specific example, a set of resources usable in each unicast may be set as shown in Tables 12 and 13 described above. Thereafter, when the transmitting terminal transmits data / SA, the transmitting terminal may indicate a specific resource within a set of resources available through SCI.

Table 14

In addition, as an example, the operations related to Table 14 described above may be performed in the same numerology (i.e. SCS and CP length). At this time, as an example, when performing sidelink transmission / reception within one carrier (or a specific carrier), the terminal may be difficult to implement when considering different pneumatics in performing transmission / reception operations within the carrier. Therefore, when performing the operation shown in Table 14 on a specific carrier, only the same pneumatic roller can be considered. On the other hand, in the case of a plurality of sidelink carriers, it may be easy to implement even if different numerology is applied, and may be applicable, and will be described later with respect to different numerology.

As another example, referring to FIG. 8, the SCI field may further include a PSFCH presence indicator (PSFCH presence indicator). At this time, the indicator on whether to transmit the PSFCH may provide information on whether to transmit the PSFCH to the terminal receiving the data / SA.

More specifically, referring to FIG. 8, the transmitting terminal may transmit data / SA 810-2 from SL carrier # 1 to the receiving terminal based on unicast # 0. At this time, the SCI field included in the data / SA 810-2 may include an indicator as to whether to transmit the PSFCH. At this time, as illustrated in FIG. 8, when the PSFCH 840-3 is transmitted in a symbol after the data / SA 810-2, an indicator of whether the PSFCH is transmitted may indicate this. Through this, the receiving terminal can check whether the PSFCH is transmitted in the resource area for data.

At this time, the receiving terminal can know whether the PSFCH is transmitted through an indicator of whether the PSFCH is transmitted, and according to whether the PSFCH is transmitted, the OFDM symbol used by the PSFCH in the resource area for data / SA may be further utilized.

That is, the SCI can indicate not only the sidelink resource set indication, but also the PSFCH presence indication in the same slot, thereby improving resource use efficiency.

In more detail, referring to FIG. 8, data / SAs 810-1 and 810-2 for Unicast # 0 may be transmitted in SL carrier # 0 and SL carrier # 1, respectively. In addition, PSFCH for Unicast # 0 (840-1) may be transmitted on SL carrier # 0. That is, a plurality of resource sets through which data / SA is transmitted is SL carrier # 0 and SL carrier # 1, and a specific resource set through which PSFCH is transmitted may be SL carrier # 0. Also, data / SA for Unicast # 1 (820-1, 820-2) may be transmitted on SL carrier # 0 and SL carrier # 1, respectively. In addition, PSFCH for Unicast # 1 (840-2) can be transmitted on SL carrier # 1. That is, a plurality of resource sets through which data / SA is transmitted may be SL carrier # 0 and SL carrier # 1, and a specific resource set through which PSFCH is transmitted may be SL carrier # 1. In this case, as an example, PSFCH 840-3 may be transmitted in the OFDM symbol after data / SA 810-2 transmitted in the same slot in SL carrier # 1 among data / SA for Unicast # 1. At this time, the SCI field of the data / SA 810-2 includes an indicator as to whether or not the PSFCH is transmitted, and may indicate whether the PSFCH 840-3 is present. That is, whether or not the PSFCH 840-3 is received may be indicated through an indicator of whether the SCI transmits the PSFCH, as described above.

In addition, as an example, in the case of a mode 1 unicast session (or a mode 3 unicast session), the base station may control the sidelink resource to be utilized. Accordingly, the base station can recognize in advance whether PSFCH is transmitted or received by the terminals in a slot in which sidelink data / SA transmission / reception is used between specific terminals. At this time, as an example, when the transmission of two channels is multiplexed in one slot and transmitted, the base station may instruct the data / SA transmitting terminal whether DCS is present or not in the scheduled slot through the DCI signaling. have. At this time, the transmitting terminal may provide information received through DCI signaling to the receiving terminal through the SCI field for the receiving terminal. Through this, the receiving terminal can check the area of the resource through which the sidelink data / SA is transmitted.

As another example, FIGS. 9 and 10 are diagrams illustrating a timing determination method for PSFCH transmission based on different neurology.

As described above, implementation may be easy even when different pneumatics are applied to a plurality of carriers. At this time, as an example, when a unicast and / or groupcast session establishment is performed, the number of sidelink carriers to which data is transmitted and received by related terminals may be determined in advance. As another example, the number of sidelink carriers to which the terminals associated with the session will perform HARQ feedback transmission may also be determined in advance. At this time, as an example, at least one or more of the number of sidelink carriers to perform data transmission and reception and the number of sidelink carriers to perform HARQ feedback transmission may be set in advance or set to respective terminals by a network. , It is not limited to the above-described embodiment.

As another example, UE 1 and UE 2 may perform V2X sidelink communication (e.g. unicast / groupcast) on a plurality of carriers (multi-carrier). In this case, as an example, two or more terminals may perform data transmission and reception based on unicast and / or groupcast on five sidelink carriers. However, this is only one example and is not limited to the above-described embodiment. That is, two terminals can perform data transmission and reception through a plurality of sidelink carriers.

Here, a terminal transmitting data may transmit PSCCH / PSSCH at different timings in each carrier. That is, the timing of PSCCH / PSSCH transmission in each carrier may be different. However, the HARQ feedback timing for PSCCH / PSSCH transmitted at different timings in each carrier is the same and can be performed on a specific carrier. In this case, as an example, HARQ feedback may be set to be transmitted only on a specific carrier. For example, HARQ-feedback transmission may be performed only on a specific carrier based on network configuration or preset information.

For example, when HARQ feedback transmission is performed only on a specific carrier, reliability of feedback channel transmission may be increased, and wide coverage may be provided. Therefore, HARQ feedback transmission can be performed only on a specific carrier. In this case, as an example, a case in which HARQ feedback transmission is performed on the PSSCH received from SL carriers # 0 to 4 in SL carrier # 0 may be considered. However, this is only an example, and may be set differently. That is, the transmitting terminal can perform each PSCCH / PSSCH transmission through five carriers. At this time, the receiving terminal can transmit all of the corresponding HARQ feedback information for each carrier on a specific set SL carrier (i.e. SL carrier # 0).

At this time, as described above, when transmitting HARQ feedback information for a plurality of sidelink carriers to one sidelink carrier, as described above, PSCCH / PSSCHs indicating PSFCH transmission have the same slot timing (ie Slot k). It does not receive at, but can be decided to perform feedback transmission at the same timing. At this time, PSFCH transmission may be performed based on PSFCH resource indicator information of the last received PSCCH / PSSCH on the time domain among PSCCH / PSSCHs associated with PSFCH transmission. That is, PSFCH transmission may be performed based on PSFCH resource indicator information provided by the latest (or latest) PSCCH / PSSCH among PSCCH / PSSCHs indicating PSFCH transmission.

As another example, referring to FIG. 9, sidelink resource sets having different neurology may be set. At this time, as described above, when determining the feedback channel timing, the feedback channel timing may be determined in consideration of sidelink resource sets having different numerology. At this time, when the pneumatics are different, the length of the slot may be different. More specifically, referring to Table 15 below, the number of slots included in 10 ms may be different based on the neuromerology. For example, if the SCS is 30Khz, the number of slots included in 10ms may be twice the number of slots included in 10ms when the SCS is 15Khz. That is, based on the same time interval, one slot when the SCS is 15Khz may correspond to two slots when the SCS is 30Khz.

That is, the number of slots included in the same time interval may be different based on the neuromerology.

Table 15

In consideration of the above, the feedback channel timing may be determined. In this case, when the neurology is different in a plurality of carriers, a feedback channel may be determined based on HARQ timing indicated (or determined) based on a slot in which a data channel is transmitted and a slot in which an overlapping feedback channel is transmitted.

In more detail, referring to FIG. 9 (a), it is possible to consider a case in which feedback information for PSCCH / PSSCH is transmitted on a carrier whose SCS is 30 Khz in a carrier whose SCS is 60 Khz. At this time, based on Table 15, two slots when the SCS is 60Khz may correspond to one slot when the SCS is 3OKhz. In addition, it is possible to consider a case where feedback information is transmitted in the next slot of a slot in which the PSCCH / PSSCH is transmitted. For example, when the PSCCH / PSSCH is transmitted in one slot 910-1 in a carrier with SCS of 60Khz, the feedback information will be transmitted in the next slot 920-1 based on the slot in a carrier with SCS of 30Khz. Can be. That is, the feedback information may be transmitted in a slot next to a slot in the case where the SCS is 30Khz corresponding to two slots when the SCS is 60Khz, and may be a slot corresponding to “920-2” in FIG. 9 (a). . In this case, as an example, a case where a PSCCH / PSSCH is transmitted in a plurality of slots 910-1 in a carrier of 60Khz may be considered. That is, in the carrier of 60Khz, PSCCH / PSSCH can be transmitted in one slot as well as a case in which a plurality of slots 910-1 are transmitted. At this time, as an example, as shown in FIG. 9 (a), PSCCH / PSSCH may be transmitted in 60Khz SCS slots (two e.g.) corresponding to one slot of 30Khz SCS. As another example, PSCCH / PSSCH may be transmitted in 60Khz SCS slots (4 e.g. 4) corresponding to one 15Khz SCS slot. In this case, as an example, it is also possible to consider a case in which at least one of the four slots is transmitted. In this case, as an example, when the PSCCH / PSSCH is transmitted in a plurality of slots 910-1 in a carrier with an SCS of 60Khz, the feedback information is based on a slot in a carrier with an SCS of 30Khz in the next slot 920-1. Can be sent from. That is, the feedback information may be transmitted in a slot next to a slot when the SCS corresponding to the two slots 910-1 when the SCS is 60Khz is 30Khz, and to “920-1” in FIG. 9 (a). It may be a corresponding slot.

In addition, as an example, when the PSCCH / PSSCH is transmitted on a carrier having an SCS of 60Khz, and the feedback information is transmitted on a carrier of 15Khz, the same may be applied as described above. At this time, four slots of the carrier of 60Khz may correspond to one slot of the carrier of 15Khz, and feedback information may be transmitted based on the same method.

That is, when a sidelink resource for transmitting a feedback channel for PSCCH / PSSCH has a lower SCS index value, when k = 1 as a feedback timing for sidelink data received in a slot based on a larger SCS index ( The next slot) may be slots corresponding to “920-1” and “920-2” of FIG. 9 (a). In addition, as an example, the feedback timing may be equally applied when k> 1, and is not limited to the above-described embodiment.

In addition, as an example, referring to FIG. 9 (b), it is possible to consider a case in which feedback information for PSCCH / PSSCH is transmitted on a carrier having an SCS of 60Khz in a carrier having an SCS of 30Khz. At this time, based on Table 15, two slots when the SCS is 60Khz may correspond to one slot when the SCS is 3OKhZ. In addition, it may be considered that the feedback information is transmitted in the next slot of the slot in which the PSCCH / PSSCH is transmitted (k = 1). In this case, as an example, the same can be applied to the case where k> 1 refers to a slot subsequent to k = 1 instead of the next slot, but will be described below based on the case of k = 1.

For example, when the PSCCH / PSSCH is transmitted in one slot 910-3 in a carrier with an SCS of 30Khz, the feedback information will be transmitted in the next slot (k = 1) based on the slot in the carrier with an SCS of 30Khz. Can be. However, as described above, since two slots when the SCS is 60Khz can correspond to one slot when the SCS is 3OKhz, a criterion for a slot to which feedback information is transmitted may be unclear. Considering this, the feedback information may be transmitted in the last slot 920-3 among slots corresponding to the case where the SCS is 30Khz. That is, in a slot in which a data channel having a low SCS value is transmitted, in a slot corresponding to k = 1 and a slot corresponding to the most temporally overlapping slot in the time domain (eg, slots corresponding to 920-3 and 920-4) Feedback channel transmission can be performed.

In this case, the feedback information for the PSCCH / PSSCH in a carrier with an SCS of 15Khz can be applied in the same way when the SCS is transmitted in a carrier with an SCS of 60Khz, and at this time, the last slot (920-4) among slots of a carrier with an SCS of 60KhZ. In the feedback information may be transmitted.

In addition, as an example, referring to FIG. 9C, since the SCS values are the same, it may be performed with the same slot timing analysis for the feedback channel transmission timing. For example, when the PSCCH / PSSCH is transmitted in one slot 910-5 in a carrier with SCS of 30Khz, the feedback information is transmitted in the next slot (k = 1) based on the slot in the carrier with SCS of 30Khz. Can be. At this time, the same SCS Invar, feedback information may be transmitted in the next slot 920-5.

In addition, as an example, when the PSCCH / PSSCH is transmitted in one slot 910-6 in a carrier with an SCS of 60Khz, the feedback information is based on a slot in a carrier with an SCS of 60Khz in the next slot (k = 1). Can be sent. At this time, the same SCS Invar, feedback information may be transmitted in the next slot 920-6. In addition, when PSCCH / PSSCH is transmitted in each slot, feedback information may be transmitted in the next slot in the same manner, as described above.

In addition, referring to FIG. 10, it may be a method of performing feedback transmission when PSCCH / PSSCH is transmitted on a plurality of carriers. In this case, as an example, the PSFCH transmission timing in slot n transmitted from SL carrier # 0 as described above may be performed with k = 1 (ie, the next slot). In addition, in SL carrier # 1, PSFCH transmission timing in slot y may be instructed (or determined) to be performed in slots at k = 1.

At this time, referring to Figure 10 (a), SL carrier # 0 may be a 60 kHz SCS, SL carrier # 1 may have a 30 kHz SCS. At this time, feedback transmission for the sidelink data 1010-1 received in slot n of SL carrier # 0 may be performed in slot n + 1 (1010-2) in the same SL carrier # 0 corresponding to k = 1. have. In this case, it is possible to consider a case where feedback transmission for the sidelink data 1010-2 received in slot y in SL carrier # 1 (30 kHz SCS) indicates (or determines) information corresponding to k = 1. In this case, the determined meaning may mean that feedback transmission is always performed in a specific slot after a slot that receives data without signaling, and is not limited to the above-described embodiment.

At this time, since SL carrier # 1 is based on a 30kHz SCS, slot y + 1 and the data received from SC carrier # 0 and # 1 in the last slot (1020-1) of SL carrier # 0 overlapping in the time domain. Feedback (eg HARQ-ACK) transmission may be performed. In this case, as an example, the feedback may include other feedback information (e.g. CSI) as well as HARQ-ACK information, and is not limited to the above-described embodiment. In the case of other feedback information, such as CSI, the feedback transmission may be set or indicated in the slot 1020-1 in the SL carrier # 0. In addition, the feedback transmission timing may be set or indicated in slot y + 1 (10 30) in SL carrier # 1. At this time, both of the feedback transmissions for the two SL carriers may need to be performed in slot k + 1 (1020-1) of SL carrier # 0. In this case, as an example, based on the above, the feedback information may be set or directed to be transmitted only in SL carrier # 0, and based on this, the feedback information may be transmitted in slot k + 1 (1020-1).

In addition, referring to FIG. 10 (b), SL carrier # 0 may have a 60 kHz SCS, and SL carrier # 1 may have a 15 kHz SCS. At this time, feedback transmission for the sidelink data 1010-3 received in slot n of SL carrier # 0 may be performed in slot n + 1 (1020-2) in the same SL carrier # 0 corresponding to k = 1. have. In this case, a case in which feedback transmission for the sidelink data 1010-4 received in slot y in SL carrier # 1 (15 kHz SCS) indicates (or determines) information corresponding to k = 1 may be considered. In this case, the determined meaning may mean that feedback transmission is always performed in a specific slot after a slot that receives data without signaling, and is not limited to the above-described embodiment.

At this time, since SL carrier # 1 is based on 15kHz SCS, slot y + 1 (1040) and the last slot (1020-2) of SL carrier # 0 overlapping in the time domain are received by SL carrier # 0 and # 1. It is possible to perform transmission for feedback on data (eg HARQ-ACK). In this case, as an example, the feedback may include other feedback information (e.g. CSI) as well as HARQ-ACK information, and is not limited to the above-described embodiment. In the case of CSI, which is another feedback information, the feedback transmission is set or indicated in the slot 1010-3 of SL carrier # 0 in FIG. 10 (b), and the feedback in slot y + 1 (1040) in the SL carrier # 1 likewise. Consider a case where transmission timing is set or indicated. At this time, both of the feedback transmissions for the two SL carriers can be performed in slot k + 1 (1020-2) of SL carrier # 0. As another example, in the case of CSI, if the feedback transmission is set or instructed only in the slot 1010-3 of SL carrier # 0 slightly differently from FIG. 10 (b), then, the feedback transmission for SL carrier # 0 is SL It can be performed as it is in the slot 1010-3 of carrier # 0. On the other hand, if the feedback transmission timing is set or indicated only in the SL carrier # 1 slot y + 1 1040, the feedback transmission is the SL carrier # corresponding to the SL carrier # 1 slot y + 1 1040 in the time domain. It can be performed in the last slot k + 1 (1020-2) of 0. As an example, at this time, as an example, feedback information may be set or directed to be transmitted only in SL carrier # 0 based on the above, and based on this, feedback information may be transmitted in slot k + 1 (1020-2). .

11 is a diagram showing a method of transmitting a PSFCH based on a plurality of resource sets.

Referring to FIG. 11, at least two UEs may establish a unicast and / or groupcast session. (S1110) At this time, as an example, as described in FIGS. 1 to 10, the UE is based on a discovery procedure. They can recognize the surrounding terminals and establish a session. At this time, it may be considered whether a plurality of resource sets are set based on sessions established in at least two terminals. (S1120) At this time, for example, unicast is a terminal corresponding to a source ID and a terminal corresponding to a destination ID. Can be involved in this session. Also, in the case of a group cast, two or more terminals may be associated with one session based on the destination ID. Considering the above-described situation, a case in which a plurality of resource sets are set in a session established in at least two terminals may be considered. At this time, the resource set may be at least one of a carrier, a BWP, and a resource pool, as described above. Or, as an example, the resource set may be set based on a combination of carrier, BWP and resource pool, and is not limited to the above-described embodiment. At this time, it is possible to consider a case in which a plurality of resource sets are set based on sessions established in two terminals. That is, a case where different paths for data transmission exist in two terminals may be considered. In this case, the transmitting terminal of the two terminals may transmit each data / SA through each set of resources. (S1130) Thereafter, the receiving terminal of the two terminals receives data / SA received from the respective resource sets. Each of the feedback information for can be transmitted to the transmitting terminal through one set of resources. (S1140) At this time, as described above in FIGS. 1 to 10, at this time, as an example, one feedback information is transmitted The resource set may be determined by the network or may be determined in advance. As another example, one resource set to which feedback information is transmitted may be indicated to a data receiving terminal to perform feedback transmission through a DCI field by a base station and / or an SCI field of a data transmission terminal. Meanwhile, as an example, the PSFCH may be transmitted through a specific physical resource in one specific resource set through which feedback information is transmitted, as described above. As another example, the PSFCH transmission presence indicator in the SCI field may indicate whether PSFCH transmission is performed on a specific sidelink resource (e.g. slot). That is, whether PSFCH is transmitted on each resource may also be indicated through SCI, and is not limited to the above-described embodiment. That is, as an embodiment from the viewpoint of the data transmission terminal, not only is indicated through the SCI field to use a specific resource set among the plurality of resource sets for data transmission for feedback transmission, but also feedback within the same slot resource where data transmission is performed Information on whether a transmission is present may also be indicated through the SCI field.

In addition, when there is only one resource set established based on a session established in two terminals, the transmitting terminal of the two terminals may transmit data / SA through one set of resources. (S1150) The receiving terminal may transmit feedback information on the received data / SA to the transmitting terminal through a corresponding resource set, as described above.

12 is a diagram showing a method of transmitting a PSFCH based on a plurality of carriers.

At least two terminals may establish a unicast and / or groupcast session. (S1210) At this time, as described above, the terminal corresponding to the source ID and the terminal corresponding to the destination ID are associated with the session. Can be. Also, in the case of a group cast, two or more terminals may be associated with one session based on the destination ID. Considering the above-described situation, a case in which a plurality of resource sets are set in a session established in at least two terminals may be considered. At this time, a plurality of carriers may be set in the two terminals. As an example, as described above, in the case of a plurality of carriers, different numerology may be applied. At this time, among the two terminals, the transmitting terminal may transmit each data / SA to the receiving terminal through a plurality of carriers. (S1220) Thereafter, the receiving terminal transmits feedback information for each data / SA to one carrier. Can be transmitted to the transmitting terminal. (S1230) At this time, as described above with reference to FIGS. 1 to 11, the SCS of the carrier for which the feedback information is transmitted may be different from the SCS for which data / SA is transmitted. That is, different numerology may be applied to each carrier. At this time, when the SCS of the carrier transmitting the feedback information is larger than the SCS transmitted by the data / SA (S1240), there are a plurality of slots capable of transmitting feedback information, and feedback information may be transmitted through the last slot of the corresponding slot. (S1250) At this time, as described in Table 15, the number of slots included in the same time interval may be different based on different SCS. Therefore, the number of slots corresponding to the same time interval in each SCS may be different. As an example, one slot in the case of 3OKhz SCS in the same time interval may correspond to two slots in the case of 60Khz SCS, as described above.

Considering the above points, when the SCS of a carrier transmitting feedback information is larger than the SCS transmitted by data / SA, a plurality of slots capable of transmitting feedback information may be provided. That is, the number of slots corresponding to the SCS transmitting the feedback information may be more than the number of slots corresponding to the SCS transmitted by the data / SA in the same time period. Therefore, there may be a plurality of slots through which feedback information can be transmitted. At this time, the slot in which the feedback information is transmitted may be the last slot among the corresponding slots. (S1250) At this time, as described above with reference to FIGS. 9 and 10, the slot in which the feedback information is transmitted to prevent resource collision is the corresponding slot. It can be decided as the last slot. As another example, when the SCS of the carrier transmitting the feedback information is larger than the SCS transmitted by the data / SA, the information on the slot through which the feedback information is transmitted may be indicated through the SCI. That is, a specific slot among slots capable of transmitting feedback information may be indicated through SCI, and feedback information may be transmitted from the corresponding slot.

In addition, when the SCS of the carrier transmitting the feedback information is not larger than the SCS transmitted by the data / SA (S1240), there is only one slot in which the feedback information can be transmitted, and the feedback information can be transmitted in the corresponding slot. (S1260) At this time, for example, when the SCS of the carrier transmitting the feedback information is the same as the SCS transmitted by the data / SA, the feedback information may be transmitted in a corresponding slot indicated by the same slot structure. In addition, as an example, if the SCS of the carrier transmitting the feedback information is small, the SCS transmitted by the data / SA corresponds to the SCS transmitting the feedback information than the number of slots corresponding to the SCS transmitted by the data / SA in the same time interval. There may be fewer slots to play. Therefore, one slot capable of transmitting feedback information may be one. At this time, the feedback information may be transmitted through the corresponding slot, as described above in FIGS. 9 and 10.

13 is a view showing a base station apparatus and a terminal apparatus.

The base station apparatus 1300 may include a processor 1320, an antenna unit 1312, a transceiver 1314, and a memory 1316.

The processor 1320 performs baseband-related signal processing, and may include an upper layer processor 1330 and a physical layer processor 1340. The upper layer processing unit 1330 may process operations of a medium access control (MAC) layer, a radio resource control (RRC) layer, or more. The physical layer processor 1340 may process operations of a physical (PHY) layer (eg, uplink reception signal processing and downlink transmission signal processing). In addition to performing baseband-related signal processing, the processor 1320 may control overall operation of the base station apparatus 1300.

The antenna unit 1312 may include one or more physical antennas, and if a plurality of antennas are included, the antenna unit 1312 may support multiple input / output (MIMO) transmission and reception. The transceiver 1314 may include a radio frequency (RF) transmitter and an RF receiver. The memory 1316 may store information processed by the processor 1320, software related to the operation of the base station apparatus 1300, an operating system, and applications, and may include components such as a buffer.

The processor 1320 of the base station 1300 may be set to implement the operation of the base station in the embodiments described in the present invention.

The terminal device 1350 may include a processor 1370, an antenna unit 1362, a transceiver 1362, and a memory 1366.

The processor 1370 performs baseband-related signal processing, and may include an upper layer processing unit 1380 and a physical layer processing unit 1362. The upper layer processor 1380 may process operations of the MAC layer, the RRC layer, or higher layers. The physical layer processor 1390 may process operations of the PHY layer (eg, downlink reception signal processing and uplink transmission signal processing). In addition to performing baseband-related signal processing, the processor 1370 may control overall operation of the terminal device 1350.

The antenna unit 1362 may include one or more physical antennas, and if a plurality of antennas are included, MIMO transmission and reception may be supported. The transceiver 1364 may include an RF transmitter and an RF receiver. The memory 1366 may store information processed by the processor 1370, software related to an operation of the terminal device 1350, an operating system, an application, and may include components such as a buffer.

The processor 1370 of the terminal device 1350 may be set to implement the operation of the terminal in the embodiments described in the present invention.

In more detail, as an example, the processor 1320 of the base station apparatus 1300 may collect location information of a plurality of terminals and initiate a discovery procedure for unicast / groupcast. Further, as an example, the processor 1320 of the base station apparatus 1300 may provide information on session establishment to the terminal apparatus 1350. In addition, the processor 1320 of the base station apparatus 1300 may provide information on a specific resource to which feedback information is transmitted among a plurality of resource sets to the terminal apparatus 1350. In addition, as an example, the processor 1320 of the base station apparatus 1300 may provide control information for a plurality of resource sets to the terminal apparatus 1350.

 As another example, the processor 1370 of the terminal device 1350 may perform side link communication with another terminal device. In this case, as an example, the processor 1370 of the terminal device 1350 may establish a groupcast and / or unicast session with another terminal device 1350. Further, as an example, the processor 1370 of the terminal device 1350 may perform data communication with another terminal device 1350 through a plurality of resource sets based on the established session. Further, as an example, the processor 1370 of the terminal device 1350 may provide resource information to which feedback information for a plurality of resource sets is transmitted to other terminal devices. Further, as an example, the processor 1370 of the terminal device 1350 may provide information on a slot through which the PSFCH is transmitted to other terminal devices. Further, as an example, the processor 1370 of the terminal device 1350 may transmit control information for sidelink data to another terminal device through the PSCCH. In addition, the processor 1370 of the terminal device 1350 may transmit data information on sidelink data to another terminal device through the PSSCH. Further, as an example, the processor 1370 of the terminal device 1350 may transmit feedback information to another terminal device based on the received sidelink data.

The various embodiments of the present disclosure are not intended to list all possible combinations, but are intended to describe representative aspects of the present disclosure, and the details described in the various embodiments may be applied independently or in combination of two or more.

Further, various embodiments of the present disclosure may be implemented by hardware, firmware, software, or a combination thereof. For implementation by hardware, one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), Universal It can be implemented by a processor (general processor), a controller, a microcontroller, a microprocessor.

The scope of the present disclosure includes software or machine-executable instructions (eg, operating systems, applications, firmware, programs, etc.) that cause actions according to the methods of various embodiments to be executed on a device or computer, and such software or Instructions include a non-transitory computer-readable medium that is stored and executable on a device or computer.

The present invention can be applied to a Sidelink feedback procedure in a NR (New Radio) Vehicle To Everything (V2X) system, and can be applied when transmitting and receiving sidelink feedback information in an NR V2X system.

Claims (1)

1. In the method of transmitting feedback information to the terminal in the NR (New Radio) V2X (Vehicle to everything) system,

   Establishing a session by the first terminal based on at least one of unicast and groupcast with the second terminal;

   Transmitting data through the resource set to the second terminal by the first terminal based on the established session; And

   The first terminal receiving feedback information based on the data from the second terminal; includes,

   When a plurality of resource sets are set in the first terminal and the second terminal, the second terminal transmits feedback information on data of the plurality of resource sets to the first terminal through one specific resource set, How to send feedback information.

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