KR20200085643A - Method and apparatus for transmitting sidelink harq feedback information - Google Patents

Abstract

Embodiments of the present invention relate to a method and an apparatus for transmitting sidelink HARQ feedback information. According to one embodiment of the present invention, provided is a method for a reception terminal to transmit HARQ feedback information comprising the steps of: receiving configuration information for a physical sidelink feedback channel (PSFCH) resource set; receiving a physical sidelink shared channel (PSSCH) from a transmission terminal; determining a PSFCH resource used for transmission of HARQ feedback information for the PSSCH in the PSFCH resource set based on predetermined identification information; and transmitting HARQ feedback information using the PSFCH resource.

Description

Method and apparatus for transmitting sidelink HARQ feedback information {METHOD AND APPARATUS FOR TRANSMITTING SIDELINK HARQ FEEDBACK INFORMATION}

The present embodiments propose a method and apparatus for transmitting sidelink HARQ feedback information in a next generation radio access network (hereinafter referred to as "NR [New Radio]").

3GPP recently approved "Study on New Radio Access Technology", a study item for research on next-generation radio access technology (that is, 5G radio access technology), and based on this, RAN WG1 each provides for NR (New Radio) Designs for frame structures, channel coding & modulation, waveform & multiple access schemes, etc. are underway. NR is required to be designed to satisfy various QoS requirements (QoS requirements) required for each segmented and materialized usage scenario as well as improved data rate compared to LTE.

As representative NR usage scenarios, eMBB (enhancement Mobile BroadBand), mMTC (massive Machine Type Communication) and URLLC (Ultra Reliable and Low Latency Communications) have been defined, and a flexible frame structure compared to LTE to satisfy the needs of each usage scenario Design is required.

Each service scenario (usage scenario), because the data rate (data rates), latency (latency), reliability (reliability), coverage (coverage), etc. requirements are different from each other through the frequency band constituting an arbitrary NR system Based on different numerology (e.g., subcarrier spacing, subframe, transmission time interval (TTI)) as a method for efficiently satisfying the needs of each usage scenario There is a need for a method of efficiently multiplexing radio resource units of the system.

As part of this aspect, a sidelink, which is a wireless link between terminals for providing V2X service in NR, that is, transmits HARQ ACK/NACK feedback information for data transmission and reception of data on the NR sidelink Design is required.

Embodiments of the present disclosure can provide a specific method and apparatus capable of allocating radio resources for transmitting sidelink HARQ feedback information in the NR.

In one aspect, the present embodiments provide a method for a receiving terminal to transmit HARQ feedback information, receiving configuration information for a PSFCH resource set, receiving a PSSCH from a transmitting terminal, and HARQ for a PSSCH in a PSFCH resource set. It is possible to provide a method comprising determining a PSFCH resource used for transmission of feedback information based on predetermined identification information and transmitting HARQ feedback information using the PSFCH resource.

In another aspect, the present embodiments provide a PSSCH to a PSSCH using a PSFCH resource determined based on predetermined identification information in a PSFCH resource set and a step of transmitting a PSSCH to a receiving terminal in a method in which the transmitting terminal receives HARQ feedback information. It may provide a method comprising the step of receiving HARQ feedback information for.

In another aspect, the present embodiment is a receiving terminal for transmitting HARQ feedback information, receiving configuration information for the PSFCH resource set, receiving unit for receiving a PSSCH from the transmitting terminal, HARQ feedback information for the PSSCH in the PSFCH resource set It is possible to provide a terminal including a control unit for determining the PSFCH resource used for transmission of the information based on predetermined identification information and a transmission unit for transmitting HARQ feedback information using the PSFCH resource.

In another aspect, the present embodiments are for a PSSCH using a PSFCH resource determined based on predetermined identification information in a PSFCH resource set and a transmitter for transmitting a PSSCH to a receiving terminal in a transmitting terminal receiving HARQ feedback information. It is possible to provide a terminal including a receiver for receiving HARQ feedback information.

According to the present embodiments, it is possible to provide a method and apparatus for transmitting sidelink HARQ feedback information capable of allocating radio resources for transmitting sidelink HARQ feedback information in NR.

1 is a diagram briefly showing the structure of an NR wireless communication system to which the present embodiment can be applied.
2 is a diagram for explaining a frame structure in an NR system to which the present embodiment can be applied.
3 is a diagram for describing a resource grid supported by a radio access technology to which the present embodiment can be applied.
4 is a diagram for describing a bandwidth part supported by a radio access technology to which the present embodiment can be applied.
5 exemplarily shows a synchronization signal block in a radio access technology to which the present embodiment can be applied.
6 is a diagram for explaining a random access procedure in a radio access technology to which the present embodiment can be applied.
7 is a view for explaining CORESET.
8 is a diagram for describing various scenarios for V2X communication.
9 shows an example of a terminal 1 (UE1), a terminal 2 (UE2) performing sidelink communication, and a sidelink resource pool used by them.
10 is a diagram for explaining a method of bundling and transmitting HARQ feedback information in V2X.
11 illustrates the type of V2X transmission resource pool.
12 is a diagram illustrating an example of symbol level alignment among different SCSs in different SCSs to which the present embodiment can be applied.
13 is a diagram illustrating a conceptual example of a bandwidth part to which the present embodiment can be applied.
14 is a diagram illustrating a procedure for a receiving terminal to transmit sidelink HARQ feedback information according to an embodiment.
15 is a diagram illustrating a procedure for a transmitting terminal to receive sidelink HARQ feedback information according to an embodiment.
16 is a view showing the configuration of a receiving terminal according to another embodiment.
17 is a diagram showing the configuration of a transmitting terminal according to another embodiment.

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, the same components may have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing the present embodiments, when it is determined that a detailed description of a related known configuration or function may obscure the gist of the present technical concept, the detailed description may be omitted. When “include”, “have”, “consist of” and the like referred to in this specification are used, other parts may be added unless “~ only” is used. When a component is expressed in singular, it may include a case in which plural is included unless otherwise specified.

Further, in describing the components of the present disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, order, or number of the component is not limited by the term.

In the description of the positional relationship of components, when two or more components are described as being "connected", "coupled" or "connected", etc., two or more components are directly "connected", "coupled" or "connected" It may be understood that "but may be," two or more components and other components may be further "interposed" to be "connected", "coupled" or "connected". Here, other components may be included in one or more of two or more components that are "connected", "coupled" or "connected" to each other.

In the description of temporal flow relations related to components, operation methods, production methods, etc., temporal sequential relationships such as "after", "after", "after", "before", etc. Or, when a flow sequential relationship is described, it may also include a case where the "direct" or "direct" is not continuous unless used.

On the other hand, when a numerical value for a component or its corresponding information (for example, level) is mentioned, even if there is no explicit description, the numerical value or its corresponding information is various factors (eg, process factors, internal or external impact, Noise, etc.).

The wireless communication system in the present specification means a system for providing various communication services such as voice and data packets using radio resources, and may include a terminal and a base station or a core network.

The embodiments disclosed below can be applied to a wireless communication system using various wireless access technologies. For example, the present embodiments are code division multiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single-electron frequency division multiple access (SC-FDMA). Alternatively, it may be applied to various radio access technologies such as non-orthogonal multiple access (NOMA). In addition, the radio access technology may mean not only a specific access technology, but also a communication technology for each generation established by various communication consultation organizations such as 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, and ITU. For example, CDMA may be implemented with a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented with radio technologies such as global system for mobile communications (GSM)/general packet radio service (GPRS)/enhanced data rates for GSM evolution (EDGE). OFDMA may be implemented with wireless technologies such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, and provides backward compatibility with a system based on IEEE 802.16e. UTRA is part of a universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of evolved UMTS (E-UMTS) using evolved-UMTS terrestrial radio access (E-UTRA), adopts OFDMA in the downlink and SC- in the uplink. Adopt FDMA. As described above, the present embodiments may be applied to a currently disclosed or commercialized wireless access technology, or may be applied to a wireless access technology currently being developed or to be developed in the future.

On the other hand, the terminal in the present specification is a comprehensive concept meaning a device including a wireless communication module that performs communication with a base station in a wireless communication system, WCDMA, LTE, NR, HSPA and IMT-2020 (5G or New Radio), etc. It should be interpreted as a concept including all of User Equipment (UE), Mobile Station (MS) in GSM, User Terminal (UT), Subscriber Station (SS), and wireless device. In addition, the terminal may be a user portable device such as a smart phone depending on the type of use, or in a V2X communication system, it may mean a vehicle, a device including a wireless communication module in the vehicle, or the like. In addition, in the case of a machine type communication system, it may mean an MTC terminal, a M2M terminal, a URLLC terminal, etc. equipped with a communication module to perform machine type communication.

The base station or cell herein refers to an end that communicates with a terminal in terms of a network, Node-B (Node-B), evolved Node-B (eNB), gNode-B (gNB), Low Power Node (LPN), Sectors, sites, various types of antennas, BTS (Base Transceiver System), access points, points (e.g., transmission points, reception points, transmission/reception points), relay nodes (Relay Node) ), mega cell, macro cell, micro cell, pico cell, femto cell, remote radio head (RRH), radio unit (RU), small cell (small cell). Also, the cell may mean to include a bandwidth part (BWP) in the frequency domain. For example, the serving cell may mean the Activation BWP of the terminal.

Since the various cells listed above have a base station that controls one or more cells, the base station can be interpreted in two ways. 1) a device that provides a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, or a small cell in relation to the wireless area, or 2) the wireless area itself. In 1), all devices that provide a predetermined wireless area are controlled by the same entity, or all devices that interact to configure the wireless area in a collaborative manner are instructed to the base station. Points, transmission/reception points, transmission points, reception points, and the like, according to a configuration method of a wireless area, are examples of base stations. In 2), the radio area itself, which receives or transmits a signal from the viewpoint of the user terminal or the neighboring base station, may be directed to the base station.

In this specification, a cell is a component carrier having a coverage of a signal transmitted from a transmission/reception point or a signal transmitted from a transmission/reception point, or a transmission/reception point itself. Can.

Uplink (Uplink, UL, or uplink) means a method of transmitting and receiving data to the base station by the terminal, downlink (Downlink, DL, or downlink) means a method of transmitting and receiving data to the terminal by the base station do. Downlink (downlink) may mean a communication or communication path from a multiple transmit and receive point to a terminal, and uplink (uplink) may mean a communication or communication path from a terminal to a multiple transmit and receive point. At this time, in the downlink, the transmitter may be a part of multiple transmission/reception points, and the receiver may be a part of the terminal. In addition, in the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of the multiple transmission/reception points.

The uplink and downlink transmit and receive control information through control channels such as PDCCH (Physical Downlink Control CHannel), PUCCH (Physical Uplink Control CHannel), and PDSCH (Physical Downlink Shared CHannel), PUSCH (Physical Uplink Shared CHannel), etc. The same data channel is configured to transmit and receive data. Hereinafter, a situation in which signals are transmitted/received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH is also described in the form of'transmit and receive PUCCH, PUSCH, PDCCH and PDSCH'.

In order to clarify the description, hereinafter, the technical idea is mainly focused on the 3GPP LTE/LTE-A/NR (New RAT) communication system, but the technical features are not limited to the communication system.

3GPP develops 5G (5th-Generation) communication technology to meet the requirements of ITU-R's next-generation radio access technology after research on 4G (4th-Generation) communication technology. Specifically, 3GPP develops a new NR communication technology separate from LTE-A pro and 4G communication technology, which have improved LTE-Advanced technology to meet the requirements of ITU-R with 5G communication technology. LTE-A pro and NR both refer to 5G communication technology. Hereinafter, 5G communication technology will be described with reference to NR when a specific communication technology is not specified.

The operating scenario in NR defined various operation scenarios by adding considerations for satellite, automobile, and new verticals in the existing 4G LTE scenario, and has an eMBB (Enhanced Mobile Broadband) scenario and high terminal density in terms of service. It is deployed in the range and supports the Massive Machine Communication (mmmTC) scenario that requires low data rate and asynchronous connection, and the Ultra Reliability and Low Latency (URLLC) scenario that requires high responsiveness and reliability and can support high-speed mobility. .

To satisfy this scenario, NR discloses a wireless communication system to which a new waveform and frame structure technology, low latency technology, ultra-high-bandwidth (mmWave) support technology, and forward compatible technology are applied. In particular, in the NR system, various technical changes are proposed in terms of flexibility in order to provide forward compatibility. The main technical features of NR will be described below with reference to the drawings.

<NR system general>

1 is a diagram briefly showing the structure of an NR system to which the present embodiment can be applied.

Referring to FIG. 1, the NR system is divided into a 5GC (5G Core Network) and an NR-RAN part, and the NG-RAN is controlled for a user plane (SDAP/PDCP/RLC/MAC/PHY) and user equipment (UE). It consists of gNB and ng-eNBs that provide a plane (RRC) protocol termination. gNB interconnection or gNB and ng-eNB are interconnected via Xn interface. gNB and ng-eNB are each connected to 5GC through an NG interface. The 5GC may be configured to include an access and mobility management function (AMF) in charge of a control plane such as a terminal access and mobility control function and a user plane function (UPF) in charge of a control function in user data. The NR includes support for frequency bands below 6 GHz (FR1, Frequency Range 1) and frequency bands above 6 GHz (FR2, Frequency Range 2).

gNB means a base station providing NR user plane and control plane protocol termination to the terminal, and ng-eNB means a base station providing E-UTRA user plane and control plane protocol termination to the terminal. The base station described in this specification should be understood as a meaning encompassing gNB and ng-eNB, and may be used as a meaning to distinguish the gNB or ng-eNB as necessary.

<NR wave form, numerology and frame structure>

In NR, a CP-OFDM waveform using a cyclic prefix is used for downlink transmission, and CP-OFDM or DFT-s-OFDM is used for uplink transmission. OFDM technology is easy to combine with multiple input multiple output (MIMO), and has the advantage of being able to use a receiver of low complexity with high frequency efficiency.

On the other hand, in the NR, since the demands for data rate, delay rate, and coverage for each of the three scenarios described above are different from each other, it is necessary to efficiently satisfy the requirements for each scenario through a frequency band constituting an arbitrary NR system. . To this end, a technique for efficiently multiplexing a plurality of different numerology-based radio resources has been proposed.

Specifically, the NR transmission neurology is determined based on sub-carrier spacing (sub-carrier spacing) and cyclic prefix (CP), and the μ value is used as an exponential value of 2 based on 15 kHz as shown in Table 1 below. Will be changed.

μ Subcarrier spacing Cyclic prefix Supported for data Supported for synch 0 15 Normal Yes Yes One 30 Normal Yes Yes 2 60 Normal, Extended Yes No 3 120 Normal Yes Yes 4 240 Normal No Yes

As shown in Table 1 above, the NR numerology can be divided into 5 types according to the subcarrier spacing. This is different from that in which the subcarrier spacing of LTE, one of 4G communication technologies, is fixed at 15 kHz. Specifically, the subcarrier interval used for data transmission in NR is 15, 30, 60, 120 kHz, and the subcarrier interval used for synchronization signal transmission is 15, 30, 12, 240 kHz. In addition, the extended CP is applied only to the 60 kHz subcarrier interval. On the other hand, a frame structure in NR is defined as a frame having a length of 10 ms, which is composed of 10 subframes having the same length of 1 ms. One frame can be divided into 5 ms half frames, and each half frame includes 5 subframes. In the case of a 15 kHz subcarrier interval, one subframe is composed of one slot, and each slot is composed of 14 OFDM symbols. 2 is a diagram for explaining a frame structure in an NR system to which the present embodiment can be applied.

Referring to FIG. 2, a slot is fixedly composed of 14 OFDM symbols in the case of a normal CP, but the length in the time domain of the slot may vary depending on the subcarrier interval. For example, in the case of a numerology having a 15 kHz subcarrier spacing, the slot is 1 ms long and is configured to have the same length as the subframe. On the other hand, in the case of a neurology with a 30 kHz subcarrier spacing, the slot is composed of 14 OFDM symbols, but may have two slots in one subframe with a length of 0.5 ms. That is, the subframe and the frame are defined with a fixed time length, and the slot is defined by the number of symbols, so that the time length may vary according to the subcarrier interval.

Meanwhile, the NR defines a basic unit of scheduling as a slot, and also introduces a mini-slot (or sub-slot or non-slot based schedule) to reduce transmission delay in a radio section. When a wide subcarrier interval is used, the length of one slot is inversely shortened, and thus transmission delay in a wireless section can be reduced. The mini-slot (or sub-slot) is for efficient support for the URLLC scenario and can be scheduled in units of 2, 4, and 7 symbols.

In addition, unlike LTE, uplink and downlink resource allocation is defined as a symbol level in one slot. In order to reduce HARQ delay, a slot structure capable of directly transmitting HARQ ACK/NACK in a transmission slot has been defined, and this slot structure is referred to as a self-contained structure.

NR is designed to support a total of 256 slot formats, of which 62 slot formats are used in 3GPP Rel-15. In addition, a common frame structure configuring FDD or TDD frames is supported through a combination of various slots. For example, a slot structure in which all symbols of a slot are set to downlink, a slot structure in which all symbols are set to uplink, and a slot structure in which downlink symbols and uplink symbols are combined are supported. In addition, NR supports that data transmissions are scheduled to be distributed over one or more slots. Accordingly, the base station may inform the terminal whether the slot is a downlink slot, an uplink slot, or a flexible slot using a slot format indicator (SFI). The base station may indicate a slot format by indicating an index of a table configured through UE-specific RRC signaling using SFI, and dynamically indicate through DCI (Downlink Control Information) or static or through RRC It can also be given quasi-statically.

<NR Physical Resources>

With regard to physical resources in the NR, antenna ports, resource grids, resource elements, resource blocks, and bandwidth parts are considered. do.

The antenna port is defined such that a channel carrying a symbol on the antenna port can be inferred from a channel carrying another symbol on the same antenna port. If the large-scale property of a channel carrying a symbol on one antenna port can be deduced from a channel carrying a symbol on another antenna port, the two antenna ports are QC/QCL (quasi co-located or quasi co-location). Here, a wide range of characteristics includes one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

3 is a diagram for describing a resource grid supported by a radio access technology to which the present embodiment can be applied.

Referring to FIG. 3, a resource grid may exist according to each neuromerging because the NR supports a plurality of neuromerging on the same carrier. In addition, the resource grid may exist according to the antenna port, subcarrier spacing, and transmission direction.

A resource block consists of 12 subcarriers and is defined only on the frequency domain. Further, a resource element is composed of one OFDM symbol and one subcarrier. Therefore, as shown in FIG. 3, the size of one resource block may vary according to the subcarrier interval. In addition, the NR defines "Point A", which serves as a common reference point for the resource block grid, a common resource block, and a virtual resource block.

4 is a diagram for describing a bandwidth part supported by a radio access technology to which the present embodiment can be applied.

Unlike LTE, where the carrier bandwidth is fixed at 20Mhz in NR, the maximum carrier bandwidth is set from 50Mhz to 400Mhz for each subcarrier interval. Therefore, it is not assumed that all terminals use all of these carrier bandwidths. Accordingly, in the NR, as illustrated in FIG. 4, a terminal may be used by designating a bandwidth part (BWP) within the carrier bandwidth. In addition, the bandwidth part is associated with one neurology and consists of a subset of consecutive common resource blocks, and can be dynamically activated with time. A maximum of 4 bandwidth parts are configured in the uplink and the downlink, respectively, and data is transmitted and received using the bandwidth part activated at a given time.

In the case of a paired spectrum, the uplink and downlink bandwidth parts are independently set, and in the case of an unpaired spectrum, unnecessary frequency re-tunning is prevented between downlink and uplink operation. For this, the bandwidth part of the downlink and the uplink is configured in pairs so that the center frequency can be shared.

<NR initial connection>

In NR, a terminal accesses a base station and performs a cell search and random access procedure to perform communication.

Cell search is a procedure in which a terminal synchronizes with a cell of a corresponding base station, obtains a physical layer cell ID, and acquires system information using a synchronization signal block (SSB) transmitted by the base station.

5 exemplarily shows a synchronization signal block in a radio access technology to which the present embodiment can be applied.

Referring to FIG. 5, the SSB is composed of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) occupying 1 symbol and 127 subcarriers, and 3 OFDM symbols and a PBCH spanning 240 subcarriers, respectively.

The terminal receives the SSB by monitoring the SSB in the time and frequency domain.

SSB can be transmitted up to 64 times in 5 ms. Multiple SSBs are transmitted with different transmission beams within 5 ms time, and the terminal performs detection by assuming that SSBs are transmitted every 20 ms period when viewed based on a specific one beam used for transmission. The number of beams that can be used for SSB transmission within 5 ms time may increase as the frequency band increases. For example, up to four SSB beams can be transmitted below 3 GHz, and up to eight different beams can be transmitted using up to eight different beams in the frequency band from 3 to 6 GHz and up to 64 in the frequency band above 6 GHz.

Two SSBs are included in one slot, and the starting symbol and the number of repetitions in the slot are determined according to the subcarrier interval.

Meanwhile, the SSB is not transmitted at the center frequency of the carrier bandwidth, unlike the SS of the conventional LTE. That is, the SSB may be transmitted out of the center of the system band, and when supporting broadband operation, a plurality of SSBs may be transmitted on the frequency domain. Accordingly, the UE monitors the SSB using a synchronization raster, which is a candidate frequency location for monitoring the SSB. The carrier raster and the synchronization raster, which are the center frequency location information of the channel for initial access, are newly defined in NR, and the synchronization raster has a wider frequency interval than the carrier raster, and thus supports fast SSB search of the UE. Can.

The terminal may acquire MIB through the PBCH of the SSB. The MIB (Master Information Block) includes minimum information for the UE to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, PBCH is information on the location of the first DM-RS symbol on the time domain, information for the UE to monitor SIB1 (for example, SIB1 neuromerging information, information related to SIB1 CORESET, search space information, PDCCH Related parameter information, etc.), offset information between the common resource block and the SSB (the position of the absolute SSB in the carrier is transmitted through SIB1), and the like. Here, the SIB1 numerology information is equally applied to some messages used in the random access procedure for accessing the base station after the terminal completes the cell search procedure. For example, pneumatic information of SIB1 may be applied to at least one of messages 1 to 4 for a random access procedure.

The aforementioned RMSI may mean System Information Block 1 (SIB1), and SIB1 is broadcast periodically (ex, 160 ms) in a cell. SIB1 includes information necessary for the UE to perform the initial random access procedure, and is periodically transmitted through the PDSCH. In order to receive SIB1, the UE must receive pneumatic information used for SIB1 transmission and control resource set (CORESET) information used for scheduling of SIB1 through PBCH. The UE identifies scheduling information for SIB1 using SI-RNTI in CORESET, and acquires SIB1 on the PDSCH according to the scheduling information. The remaining SIBs except SIB1 may be periodically transmitted or may be transmitted according to the terminal's request.

6 is a diagram for explaining a random access procedure in a radio access technology to which the present embodiment can be applied.

Referring to FIG. 6, when the cell search is completed, the UE transmits a random access preamble for random access to the base station. The random access preamble is transmitted through PRACH. Specifically, the random access preamble is transmitted to the base station through PRACH composed of continuous radio resources in a specific slot that is periodically repeated. Generally, a contention-based random access procedure is performed when a UE initially accesses a cell, and a non-competition-based random access procedure is performed when random access is performed for beam failure recovery (BFR).

The terminal receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), UL grant (uplink radio resource), temporary C-RNTI (Temporary Cell-Radio Network Temporary Identifier) and TAC (Time Alignment Command). Since one random access response may include random access response information for one or more terminals, a random access preamble identifier may be included to inform which terminal the included UL Grant, temporary C-RNTI, and TAC are valid. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the UE to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, that is, a Random Access-Radio Network Temporary Identifier (RA-RNTI).

Upon receiving a valid random access response, the terminal processes the information included in the random access response and performs scheduled transmission to the base station. For example, the terminal applies TAC and stores a temporary C-RNTI. In addition, by using UL Grant, data stored in the buffer of the terminal or newly generated data is transmitted to the base station. In this case, information capable of identifying the terminal should be included.

Finally, the terminal receives a downlink message for contention resolution.

<NR CORESET>

The downlink control channel in NR is transmitted in a control resource set (CORESET) having a length of 1 to 3 symbols, and transmits uplink/downlink scheduling information, slot format index (SFI), and transmit power control (TPC) information. .

Thus, in order to secure the flexibility of the system, NR introduced the concept of CORESET. CORESET (Control Resource Set) means a time-frequency resource for a downlink control signal. The UE may decode the control channel candidate using one or more search spaces in the CORESET time-frequency resource. A QCL (Quasi CoLocation) assumption for each CORESET was established, and this is used for the purpose of informing the characteristics of the analog beam direction in addition to delay spread, Doppler spread, Doppler shift, and average delay, which are characteristics assumed by the conventional QCL.

7 is a view for explaining CORESET.

Referring to FIG. 7, CORESET may exist in various forms within a carrier bandwidth in one slot, and CORESET on a time domain may consist of up to 3 OFDM symbols. In addition, CORESET is defined as a multiple of 6 resource blocks from the frequency domain to the carrier bandwidth.

The first CORESET is indicated through the MIB as part of the initial bandwidth part configuration to receive additional configuration information and system information from the network. After establishing a connection with the base station, the UE may configure by receiving one or more CORESET information through RRC signaling.

<LTE Side Link>

In the existing LTE system, to provide direct communication between terminals and V2X (especially V2V) service, radio channel and radio protocol design for direct communication between terminals (i.e., side link) was made.

With respect to the sidelink, a PSSS/SSSS, which is a synchronization signal for synchronization between a wireless sidelink transmitting end and a receiving end, and a PSBCH (Physical Sidelink Broadcasting Channel) for transmitting and receiving a related sidelink Master Information Block (MIB) have been defined, and also discovery information. A design for a physical sidelink discovery channel (PSCH) for transmission/reception, a physical sidelink control channel (PSCCH) for transmission and reception of Sidelink Control Information (SCI), and a physical sidelink shared channel (PSSCH) for transmission and reception of sidelink data was made.

In addition, for the allocation of radio resources for the sidelink, a technology has been developed that is divided into mode 1, in which the base station allocates radio resources, and mode 2, in which the terminal selects and allocates radio resources from a radio resource pool. In addition, additional technical evolution was required for the LTE system to satisfy the V2X scenario.

In this environment, 3GPP derived 27 service scenarios related to vehicle recognition in Rel-14, and determined key performance requirements according to road conditions. In addition, in the recent Rel-15, 25 more advanced service scenarios such as cluster driving, advanced driving, and long-distance vehicle sensors were derived to determine six performance requirements.

In order to satisfy these performance requirements, technology development has been conducted to improve the performance of the sidelink technology developed based on the conventional D2D communication according to the requirements of V2X. In particular, in order to apply to C-V2X (Cellular-V2X), a technology that improves the physical layer design of the side link to be suitable for a high-speed environment, resource allocation technology, and synchronization technology can be selected as the main research technology.

The sidelink described below means a link used for D2D communication developed after 3GPP Rel-12, V2X communication after Rel-14, and D2D communication requirements, V2X for each channel term, synchronization term, resource term, etc. Rel-14, 15 In the same terms regardless of the requirements. However, for the convenience of understanding, the differences in sidelinks satisfying the V2X scenario requirements are described based on the sidelink for D2D communication in Rel-12/13, if necessary. Therefore, the terms related to the sidelink described below are merely for dividing and explaining D2D communication/V2X communication/C-V2X communication for comparison difference and convenience of understanding, and are not limited to specific scenarios.

<Resource allocation>

8 is a diagram for describing various scenarios for V2X communication.

Referring to FIG. 8, a V2X terminal (denoted as a vehicle, but can be variously set such as a user terminal) may be located in the base station (eNB or gNB or ng-eNB) coverage, or may be located outside the base station coverage. For example, communication may be performed between UEs in UE coverage (UE N-1, UE G-1, UE X), and between UEs in UE coverage and UEs (ex, UE N-1, UE N-) 2) can also perform communication. Alternatively, communication may be performed between terminals (eg, UE G-1, UE G-2) outside the base station coverage.

In these various scenarios, in order to perform communication using a sidelink, a corresponding terminal requires allocation of radio resources for communication, and allocation of radio resources is largely divided into base station handling allocation and terminal selection.

Specifically, in D2D, a method of allocating a resource by a terminal includes a centralized method (Mode 1) in which a base station intervenes in resource selection and management and a distributed method (Mode 2) in which a terminal randomly selects a preset resource. Similar to D2D, C-V2X has a method in which a base station intervenes in resource selection and management (Mode 3) and a method in which a vehicle directly selects a resource in V2X (Mode 4). In Mode 3, the base station schedules the SA (Scheduling Assignment) pool resource region and the DATA pool resource region allocated thereto.

9 illustrates an example of a terminal 1 (UE1), a terminal 2 (UE2) performing sidelink communication, and a sidelink resource pool used by them.

Referring to FIG. 9, the base station is designated as an eNB, but may be a gNB or an ng-eNB as described above. In addition, the terminal is illustrated as a mobile phone as an example, it can be applied to a variety of vehicles, infrastructure devices.

In FIG. 9(a), the transmitting terminal UE1 may select a resource unit corresponding to a specific resource in a resource pool representing a set of a set of resources and transmit a sidelink signal using the resource unit. The receiving terminal UE2 may configure a resource pool through which UE1 can transmit signals and detect a transmission signal of the corresponding terminal.

Here, the resource pool may be notified by the base station when UE1 is in the connection range of the base station, or may be determined by a predetermined resource or notified by another terminal when the UE1 is outside the connection range of the base station. In general, a resource pool is composed of a plurality of resource units, and each terminal can select one or a plurality of resource units and use it to transmit its own sidelink signal.

Referring to FIG. 9(b), it can be seen that the total frequency resources are divided into NF pieces and the total time resources are divided into NT pieces to define a total of NF*NT resource units. Here, it can be said that the corresponding resource pool is repeated periodically in the NT subframe. In particular, one resource unit may appear periodically and repeatedly as shown.

Meanwhile, resource pools can be subdivided into several types. First, it may be classified according to contents of sidelink signals transmitted from each resource pool. For example, the content of the sidelink signal can be classified, and a separate resource pool can be configured for each. As the content of the sidelink signal, there may be a scheduling assignment (SA), a sidelink data channel, and a discovery channel.

The SA transmits information such as a location of a resource used for transmission of a sidelink data channel followed by a transmitting terminal and a modulation and coding scheme (MCS), MIMO transmission method, and timing advance (TA) required for demodulation of other data channels. It may be a signal including. This signal may be multiplexed and transmitted together with sidelink data on the same resource unit. In this case, the SA resource pool may mean a pool of resources that are transmitted by multiplexing SA with sidelink data.

Meanwhile, the FDM method applied to V2X communication can reduce a delay time in which data resources are allocated after SA resource allocation. For example, a non-adjacent method of separating control channel resources and data channel resources in one subframe on a time domain and an adjacent method of continuously allocating control channels and data channels in one subframe are considered.

Meanwhile, when SAs are multiplexed and transmitted together with sidelink data on the same resource unit, only a sidelink data channel in a form excluding SA information can be transmitted from the resource pool for the sidelink data channel. In other words, resource elements used to transmit SA information on individual resource units in the SA resource pool can still be used to transmit sidelink data in the sidelink data channel resource pool. The discovery channel may be a resource pool for a message that allows a transmitting terminal to transmit information such as its own ID so that an adjacent terminal can discover itself. Even if the contents of the sidelink signal are the same, different resource pools may be used according to the transmission and reception attributes of the sidelink signal.

For example, even if the same sidelink data channel or discovery message, the transmission timing determination method of the sidelink signal (for example, whether it is transmitted at the time of reception of the synchronization reference signal or by applying a certain TA there) or resource allocation method (For example, whether the base station designates the transmission resource of the individual signal to the individual transmission terminal or the individual transmission terminal selects the individual signal transmission resource in the pool itself), the signal format (e.g., each sidelink signal has one sub It can be divided into different resource pools again according to the number of symbols occupied in the frame, the number of subframes used to transmit one sidelink signal), the signal strength from the base station, and the transmit power strength of the sidelink terminal.

<Sync signal>

As described above, in the case of a V2X communication terminal, it is highly likely to be located outside the base station coverage. Even in this case, communication using a side link should be performed. For this, it is important that a terminal located outside the base station coverage acquires synchronization.

Hereinafter, based on the above description, a method of obtaining time and frequency synchronization in side link communication, particularly in communication between a vehicle, a vehicle and another terminal, and a vehicle and an infrastructure network is described.

D2D communication used SLSS (Sidelink Synchronization Signal), a synchronization signal transmitted from a base station, for time synchronization between terminals. In the C-V2X, an additional Global Navigation Satellite System (GNSS) may be considered to improve synchronization performance. However, priority may be given to the establishment of synchronization or the base station may indicate information on priority. For example, the UE first selects a synchronization signal that the base station directly transmits in determining its transmission synchronization, and if it is located outside the base station coverage, preferentially synchronizes the SLSS transmitted by the UE inside the base station coverage. To match.

On the other hand, a wireless terminal installed in a vehicle or a terminal mounted in a vehicle has relatively less problem of battery consumption, and since satellite signals such as GPS can be used for navigation purposes, time or frequency synchronization between terminals is set. Can be used to Here, the satellite signal may include a GNSS signal such as GLONAS (GLObal NAvigation Satellite System), GALILEO, BEIDOU, etc., in addition to the illustrated Global Positioning System (GPS).

Meanwhile, the sidelink synchronization signal may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS). The PSSS may be a Zadoff-chu sequence of a predetermined length or a structure similar/deformed/repeated with the PSS. Also, unlike the DL PSS, other Zadoff weight root indexes (eg, 26, 37) may be used. SSSS may be an M-sequence or a structure similar/modified/repeatable to SSS or the like. If the terminals synchronize with the base station, the SRN becomes the base station, and the SLSS becomes the PSS/SSS.

Unlike DL's PSS/SSS, PSSS/SSSS follows UL subcarrier mapping. PSSCH (Physical Sidelink synchronization channel) is the basic system information that the UE needs to first know before transmitting/receiving sidelink signals (for example, information related to SLSS, Duplex Mode (DM), TDD UL/DL configuration, resource Pool-related information, SLSS-related application type, subframe offset, broadcast information, etc.) may be a transmitted channel. The PSSCH may be transmitted on the same subframe as SLSS or on a subsequent subframe. DM-RS can be used for demodulation of PSSCH.

The SRN may be a node that transmits SLSS and PSSCH. SLSS may be in the form of a specific sequence, and PSSCH may be in the form of a sequence indicating specific information or a code word after undergoing a predetermined channel coding. Here, the SRN may be a base station or a specific sidelink terminal. In the case of partial network coverage or out of network coverage, the terminal may be an SRN.

In addition, SLSS may be relayed for sidelink communication with an out of coverage terminal as needed, and may be relayed through multiple hops. In the following description, relaying a synchronization signal is a concept that includes not only relaying a synchronization signal of a base station directly, but also transmitting a sidelink synchronization signal in a separate format according to a synchronization signal reception time point. In this way, the sidelink synchronization signal is relayed, so that the in-coverage terminal and the out-coverage terminal can perform direct communication.

<NR side link>

As described above, unlike V2X based on LTE system, there is a need for NR based V2X technology to satisfy complex requirements such as autonomous driving.

In the case of NR V2X, it is intended to provide a flexible V2X service in various environments by applying NR frame structure, numerology, and channel transmission/reception procedures. To this end, resource sharing technology between a base station and a terminal, side link carrier aggregation (CA) technology, partial sensing technology for a pedestrian terminal, and technology development such as sTTI are required.

NR V2X decided to support unicast and groupcast as well as broadcast used in LTE V2X. At this time, the target group ID was used for the groupcast and the unicast, but the use of the source ID was discussed later.

In addition, as the HARQ is supported for the QOS, the control information also includes the HARQ process ID. In LTE HARQ, PUCCH for HARQ is transmitted after 4 subframes after downlink transmission, but feedback timing in NR HARQ is, for example, a PUCCH resource indicator or a PUSCH in a DCI format 1_0 or 1_1. PUCCH resource and feedback timing may be indicated by a timing indicator (PDSCH-to-HARQ feedback timing indicator).

10 is a diagram for explaining a method of bundling and transmitting HARQ feedback information in V2X.

Referring to FIG. 10, in LTE V2X, separate HARQ ACK/NACK information is not transmitted to reduce system overhead, and for data transmission safety, a transmitting terminal can retransmit data once according to selection. However, NR V2X can transmit HARQ ACK/NACK information in terms of data transmission stability, and in this case, overhead can be reduced by bundling and transmitting the information.

That is, when the transmitting terminal UE1 transmits three pieces of data to the receiving terminal UE2 and the receiving terminal generates HARQ ACK/NACK information for this, it can be bundled and transmitted through the PSCCH. In the figure, although HARA ACK/NACK is transmitted through the PSCCH, it may be transmitted through a separate channel or another channel, and the bundled HARQ information may be composed of 3 bits or less.

On the other hand, in the frequency region below 3 GHz, FR1 will discuss 15 kHz, 30 kHz, 60 kHz, and 120 kHz as candidate groups in subcarrier spacing (SCS). In addition, it was decided to discuss 30 kHz, 60 kHz, 120 kHz, and 240 kHz as candidate groups for the FR2 for a frequency region exceeding 3 GHz as subcarrier spacing (SCS). In NR V2X, a mini-slot smaller than 14 symbols (for example, 2/4/7 symbols) may be supported as a minimum scheduling unit.

DM-RS, PT-RS, CSI-RS, SRS, AGC training signals were discussed as candidate candidates for RS.

The PSSCH multiplexing associated with the PSCCH will discuss the following four options as shown in FIG. Option 2 is similar to the multiplexing of PSCCH and PSSCH in LTE V2X.

Synchronization mechanism

The NR V2X sidelink synchronization includes sidelink synchronization signal(s) and PSBCH, and the sidelink source may include the UE with GNSS, gNB.

Resource allocation

In NR V2X sidelink communication, at least two sidelink resource allocation modes may be defined, mode 3 and mode 4. In mode 3, the base station schedules sidelink resource(s) used by the terminal for sidelink transmission. In mode 4, the terminal determines sidelink transmission resource(s) in sidelink resources configured by the base station or in preconfigured sidelink resources.

Mode 4 may cover the following resource allocation sub-modes. That is, the UE automatically selects a sidelink resource for transmission, helps to select a sidelink resource for other UE(s), is configured as a configured grant for sidelink transmission, or sidelinks of other terminal(s) Transmissions can be scheduled.

V2X resource pool (Sensing and selection windows)

The V2X terminal may perform message (or channel) transmission on a predefined (or signaled) resource pool. Here, the resource pool may refer to resource(s) defined in advance so that the UE performs the V2X operation (or may perform the V2X operation). In this case, the resource pool may be defined in terms of time-frequency, for example. Meanwhile, various types of V2X transmission resource pools may exist.

11 illustrates the type of V2X transmission resource pool.

Referring to FIG. 11(a), V2X transmission resource pool #A may be a resource pool where only (partial) sensing is allowed. V2X transmission resources selected by (partial) sensing are semi-statically maintained at regular cycles.

Referring to FIG. 11(b), V2X transmission resource pool #A may be a resource pool in which only random selection is allowed. In the V2X transmission resource pool #B, the UE may randomly select the V2X transmission resource in the selection window without performing (partial) sensing.

Here, as an example, in a resource pool in which only random selection is allowed, unlike a resource pool in which only (partial) sensing is allowed, the selected resource may be set (/signaling) so that it is not semi-reserved. The base station may be configured so that the terminal does not perform a sensing operation (based on scheduling allocation decoding/energy measurement) to perform a V2X message transmission operation on the V2X transmission resource pool.

Meanwhile, although not illustrated in FIG. 11, a resource pool capable of both (partial) sensing and random selection may exist. The base station may indicate that V2X resources can be selected by either of the partial sensing and the random selection.

In this specification, frequency, frame, subframe, resource, resource block, region, band, subband, control channel, data channel, synchronization signal, various reference signals, various signals or various messages related to NR (New Radio) Can be interpreted as meaning used in the past or present or various meanings used in the future.

NR (New Radio)

NR, which was recently conducted in 3GPP, has been designed to satisfy various QoS demands required for each segmented and specific service scenario (usage scenario) as well as improved data rate compared to LTE. In particular, as the representative service requirements (usage scenario) of NR, enhancement mobile BroadBand (eMBB), massive machine type communication (mMTC) and ultra reliable and low latency communications (URLLC) have been defined, and each service requirement (usage scenario) is required. As a method for satisfying, a flexible frame structure design compared to LTE/LTE-Advanced is required.

Each service scenario (usage scenario) is a data rate (data rates), latency (latency), reliability (reliability), coverage (requirements), etc., because the requirements (requirements) are different from each other, the frequency that constitutes an arbitrary NR system A radio resource unit based on different numerology (eg, subcarrier spacing, subframe, TTI, etc.) as a method for efficiently satisfying the needs of each service scenario through a band. It is designed to multiplex efficiently.

As a method for this, TDM, FDM or TDM/FDM based on one or more NR component carriers (s) for numerology having different subcarrier spacing values Discussions have been made on a method of supporting multiplexing and supporting one or more time units in configuring a scheduling unit in a time domain. In this regard, in NR, a subframe is defined as a type of time domain structure, and a reference numerology for defining a corresponding subframe duration. As it was decided to define a single subframe duration composed of 14 OFDM symbols of normal CP overhead based on 15 kHz SCS (Sub-Carrier Spacing), which is the same as LTE. Accordingly, in NR, a subframe has a time duration of 1 ms. However, unlike LTE, the subframe of NR is an absolute reference time duration, a slot and a mini-slot as a time unit based on actual uplink/downlink data scheduling. ) Can be defined. In this case, the number of OFDM symbols constituting the slot and the y value are determined to have a value of y=14 regardless of the SCS value in the case of a normal CP.

Accordingly, an arbitrary slot is composed of 14 symbols, and according to a transmission direction of the corresponding slot, all symbols are used for DL transmission, or all symbols are transmitted through UL. transmission, or may be used in the form of a DL portion + a gap + an UL portion.

In addition, a mini-slot consisting of a smaller number of symbols than the slot is defined in an arbitrary numerology (or SCS), and based on this, a short-length time domain scheduling interval for transmission/reception of uplink/downlink data (time-domain) The scheduling interval may be set, or a long-time time-domain scheduling interval for transmitting/receiving uplink/downlink data through slot aggregation may be configured.

In particular, in the case of transmitting/receiving data that is critical in latency, such as URLLC, based on 1 ms (14 symbols) defined in a numerology-based frame structure with a small SCS value such as 15 kHz. When scheduling is performed on a slot-by-slot basis, it may be difficult to satisfy a latency requirement, so for this purpose, a mini-slot consisting of fewer OFDM symbols than the corresponding slot is defined and based on this, a delay rate equal to the corresponding URLLC is critical. It can be defined so that scheduling of (latency critical) data is performed.

Or, as described above, by supporting multiplexing in the NR carrier (Carrier) having a different SCS value (numerology) by TDM and / or FDM method, by each numerology (numerology) A method of scheduling data according to a latency requirement based on a defined slot (or mini-slot) length is also considered. For example, as shown in FIG. 12 below, when the SCS is 60 kHz, the length of the symbol is reduced by about 1/4 compared to the case of the SCS 15 kHz, so if one slot is composed of 14 OFDM symbols, the corresponding 15 kHz-based The slot length is 1ms, while the 60kHz-based slot length is reduced to about 0.25ms.

In this way, by defining different SCS or different TTI lengths in NR, discussions are being made on how to satisfy the requirements of URLLC and eMBB, respectively.

Wider bandwidth operations

In the case of the existing LTE system, a scalable bandwidth operation for an arbitrary LTC component carrier (CC) was supported. That is, according to the frequency deployment scenario (deployment scenario), any LTE operator can configure a single LTE CC, and can configure a minimum bandwidth of 1.4 MHz to a maximum of 20 MHz, and a normal LTE terminal is a single LTE For CC, 20 MHz bandwidth transmission/reception capability was supported.

However, in the case of NR, the design is made to support NR terminals having different transmit/receive bandwidth capabilities through one wideband NR CC. Likewise, by configuring one or more bandwidth parts (BWP, bandwidth part(s)) composed of subdivided bandwidths for arbitrary NR CCs, it is flexible through different bandwidth part configuration and activation for each terminal. flexible) is required to support a wider bandwidth operation.

Specifically, in the NR, one or more bandwidth parts may be configured through one serving cell configured from the viewpoint of the UE, and the UE may configure one downlink bandwidth part in the serving cell. DL bandwidth part) and one UL bandwidth part (activation) are defined to be used for transmission/reception of uplink/downlink data. In addition, when a plurality of serving cells are set in a corresponding terminal, that is, for a terminal to which a CA is applied, one downlink bandwidth part and/or an uplink bandwidth part is activated for each serving cell. Therefore, it was defined to be used for transmitting/receiving data of uplink/downlink by using radio resources of a corresponding serving cell.

Specifically, an initial bandwidth part for an initial access procedure of a terminal is defined in an arbitrary serving cell, and one or more terminals are specified through dedicated RRC signaling for each terminal (UE -specific) A bandwidth part (bandwidth part(s)) is configured, and a default bandwidth part for a fallback operation can be defined for each terminal.

However, a plurality of downlink and/or uplink bandwidth parts are activated at the same time according to the capability and bandwidth part(s) configuration of the terminal in any serving cell. It can be defined as, but in NR rel-15, it is defined to be used by activating (activation) only one downlink bandwidth part (DL bandwidth part) and uplink bandwidth part (UL bandwidth part) at any time at any terminal. .

LTE sidelink

In the existing LTE system, design of a radio channel and a radio protocol for transmitting and receiving a sidelink, which is a direct link between terminals, is provided for direct communication between terminals and V2X (particularly V2V) service. In this regard, a PSSS/SSSS, which is a synchronization signal for synchronization between a wireless sidelink (endlink) transmitter and a receiver, and a PSBCH (Physical Sidelink Broadcasting Channel) for transmitting and receiving a sidelink Master Information Block (MIB), have been defined, and also discovery information. A design for a physical sidelink discovery channel (PSDCH) for transmission and reception, a PSCCH (physical sidelink control channel) for transmission and reception of Sidelink Control Information (SCI), and a physical sidelink shared channel (PSSCH) for transmission and reception of sidelink data was made. .

HARQ ACK/NACK feedback resource allocation method

According to the PUCCH resource allocation method for HARQ ACK/NACK feedback of the UE defined in the NR, the base station configures a PUCCH resource set composed of one or more PUCCH resources for any UE, and HARQ ACK/ for any PDSCH transmission It was defined to indicate PUCCH resource information to be used for NACK feedback through an ACK resource indicator (ARI) information area of DCI. However, the PUCCH resource set is configured for each UL BWP configured for a corresponding terminal, and it is defined to configure separate PUCCH resource sets according to the payload size of HARQ ACK/NACK for any UL BWP.

Hereinafter, a method of transmitting sidelink HARQ feedback information will be described in detail with reference to related drawings.

In the present disclosure, a receiving terminal means a terminal receiving a PSCCH and a corresponding PSSCH through a side link. In addition, the transmitting terminal means a terminal transmitting a PSCCH and a corresponding PSSCH through a side link.

In the present disclosure, a description will be given on the premise that HARQ ACK/NACK feedback information is transmitted from a receiving terminal to a transmitting terminal through a side link. However, the invention according to the present disclosure can be applied substantially the same, even if it does not contradict the technical idea, even when the HARQ ACK/NACK feedback information is transmitted from the receiving terminal to the base station.

14 is a diagram illustrating a procedure for a receiving terminal to transmit sidelink HARQ feedback information according to an embodiment.

Referring to FIG. 14, a receiving terminal may receive configuration information for a physical sidelink feedback channel (PSFCH) resource set (S1400).

When the PSSCH is received through the sidelink, the receiving terminal may transmit HARQ ACK/NACK feedback information corresponding to the received PSSCH. That is, a PSFCH resource set or a PSFCH resource pool may be configured to transmit HARQ ACK/NACK feedback information for PSSCH reception. The configuration information for the PSFCH resource set or the PSFCH resource pool may be composed of time period resource allocation information and frequency resource allocation information. In the present disclosure, resource sets and resource pools are respectively described, but the following description may be applied in substantially the same manner in both cases, unless contradicted by technical ideas.

The PSFCH resource set or PSFCH resource pool configuration information may be set by a base station through cell-specific or UE-specific higher layer signaling, or may be pre-configured. have. Alternatively, the PSFCH resource set or PSFCH resource pool configuration information may be set by a transmitting terminal or a scheduler terminal, and transmitted to a receiving terminal through a sidelink wireless channel such as PSDCH, PSCCH or PSSCH.

According to an example, the PSFCH format of the PSFCH resource may be set based on the PUCCH format. That is, the structure of the PSFCH may be set to reuse the PUCCH structure defined in the NR, for example, PUCCH format 1,2,3,4 or 5, or reuse the structure of the PSCCH.

According to an example, the PSFCH resource pool may be configured as a form independent of PSCCH or PSSCH resource pool configuration. In this case, RRC parameters for the PSFCH resource pool are set separately from RRC parameters for PSCCH/PSSCH resource pool configuration, and can be explicitly set through higher layer signaling. However, this is an example, and is not limited thereto, and RRC parameters for the PSFCH resource pool may be configured in advance.

Alternatively, according to another example, the PSFCH resource pool may be configured in association with the PSCCH or PSSCH resource pool configuration. In this case, any PSCCH or PSSCH resource pool configuration information may include configuration information for the associated PSFCH resource pool. That is, the arbitrary PSCCH or PSSCH resource pool configuration information may include slot allocation information for indicating time period resource allocation information of the corresponding resource pool. Specifically, period setting information and slot offset information for sidelink slot allocation in which a PSSCH or PSSCH resource pool is configured may be included.

In this case, as configuration information for the PSFCH resource pool, timing gap related information may be included between a sidelink slot in which each PSSCH or PSCCH resource pool is configured and a sidelink slot in which a PSFCH resource pool corresponding to the corresponding slot is configured. According to an example, when a 1:1 mapping relationship between a sidelink slot in which a PSSCH resource pool is configured and a sidelink slot in which a PSFCH resource pool is configured is established, corresponding timing gap setting information is a direct slot gap between the PSSCH and the PSFCH. gap) information. That is, when the corresponding timing gap setting value is an arbitrary K value, when the terminal receives the PSSCH in any slot #n, through the PSFCH resource pool of slot #(n+K) after the K slot, which is the timing gap setting value, HARQ ACK/NACK feedback may be transmitted.

Or, when a mapping relationship of N:1 (an integer of N>1) between the sidelink slots in which the PSFCH resource pool is configured and the PSF resource pool is configured is established, a timing gap between the PSFCH resource pools associated with the PSSCH resource pool is established. The setting information may be minimum slot gap information required. That is, when the corresponding timing gap setting value is an arbitrary M value, the UE that has received the PSSCH from an arbitrary UE corresponds through the first PSFCH resource pool after the minimum M slot from the corresponding slot for HARQ ACK/NACK feedback for this. HARQ ACK/NACK feedback information may be transmitted. That is, when the PSFCH resource pool is configured with N sidelink slots for the sidelink slots in which the PSCCH/PSSCH resource pool is configured, the M value together with the corresponding N value is set through higher layer signaling, Or, it may be pre-configured or an arbitrary M value may be defined as a function of the corresponding N value.

In this case, when the UE receives the PSSCH in any slot #n, it may transmit HARQ ACK/NACK feedback through the PSFCH resource pool in slot #(n+M). Alternatively, the terminal may transmit HARQ ACK/NACK feedback through the first PSFCH resource pool after slot #(n+M-1).

A PSFCH resource for HARQ ACK/NACK feedback for PSSCH reception of the receiving terminal may be allocated through the set PSFCH resource pool. At this time, the PSFCH resource allocation information in the PSFCH resource pool may be explicitly signaled or implicitly signaled.

Alternatively, a PSFCH resource set for HARQ ACK/NACK feedback for PSSCH reception of the receiving terminal may be set. The PSFCH resource set is configured by a base station and transmitted through cell-specific or UE-specific higher layer signaling, or is set by a transmitting terminal or a scheduler terminal, PSDCH, PSCCH or It may be transmitted through a sidelink radio channel such as PSSCH.

A PSFCH resource for HARQ ACK/NACK feedback for PSSCH reception of any UE may be allocated through the set PSFCH resource set. At this time, the PSFCH resource allocation information in the PSFCH resource set may be explicitly signaled or implicitly signaled.

Referring back to FIG. 14, when a sidelink data channel (PSSCH) is received from a transmitting terminal (S1410), the receiving terminal receives PSFCH resources used for transmission of HARQ feedback information for the PSSCH in the PSFCH resource set. It can be determined based on the predetermined identification information (S1420).

According to an example, a PSFCH resource to be used for HARQ ACK/NACK feedback for PSSCH reception at a receiving terminal among PSFCHs constituting a PSFCH resource pool or PSFCH resource set may be implicitly signaled. In this case, PSFCH resources may be allocated as a function of a sub-channel index for a subchannel in which PSCCH or PSSCH transmission has been performed.

According to an example, when PSSCH transmission is performed based on groupcast, when a plurality of receiving terminals share one implicitly signaled PSFCH, PSFCH transmission resources for HARQ ACK/NACK feedback between the plurality of receiving terminals Collision can occur. In order to prevent such a collision, a UE-specific offset may be applied in allocating PSFCH resources for HARQ ACK/NACK feedback of the sidelink terminal. The receiving terminal may derive the final PSFCH resource for HARQ ACK/NACK feedback by applying each terminal specific offset value to the PSFCH resource information implicitly signaled by the base station or the sidelink transmitting terminal or the sidelink scheduling terminal.

According to an example, the UE-specific PSFCH offset value may be set by a base station for each UE through UE-specific upper layer signaling, MAC CE signaling, or L1 control signaling. Alternatively, the terminal-specific PSFCH offset value may be set by a base station or a sidelink transmission terminal or a sidelink scheduler terminal when a group-cast session is set, and transmitted to each terminal. Alternatively, the UE-specific PSFCH offset value may be transmitted to each UE through PDCCH or PSCCH when allocating a groupcast-based PSSCH resource.

Alternatively, the terminal-specific PSFCH offset value may be implicitly set as a function of each terminal ID or the like. For example, the UE-specific PSFCH offset value can be derived as a function of the C-RNTI of the UE. Alternatively, a terminal ID for sidelink transmission and reception may be defined, and accordingly, a terminal specific PSFCH offset value may be derived. In this case, the terminal ID for transmitting/receiving the sidelink may be a terminal ID of a higher layer that is a group ID (member ID) for a group including a receiving terminal in groupcast data transmission, and the corresponding unicast or groupcast data transmission It may be in the form of a destination ID or a source ID as an identifier of a transmitting terminal. Alternatively, the terminal ID for the corresponding sidelink transmission/reception may be a sidelink physical layer ID for receiving PSCCH, such as SL-RNTI.

The terminal ID for sidelink transmission/reception is set by the base station, allocated through terminal specific upper layer signaling, or set by the sidelink transmission terminal or sidelink scheduling terminal through a sidelink radio channel such as PSDCH, PSCCH or PSSSCH. Can be sent. In addition, the terminal-specific PSFCH offset information for each sidelink receiving terminal may be transmitted to the groupcast PSSCH transmitting terminal. Specifically, the UE-specific PSFCH offset information for each receiving terminal is transmitted to the groupcast PSSCH transmitting terminal through upper layer signaling or MAC CE signaling or L1 control signaling by the base station, or the corresponding group through the sidelink radio channel by the scheduler terminal It may be transmitted to the cast PSSCH transmission terminal.

According to an example, in allocating a PSFCH resource for HARQ ACK/NACK feedback for PSSCH reception, whether to apply a UE-specific PSFCH offset may be additionally indicated. That is, in deriving a PSFCH resource for HARQ ACK/NACK feedback for a corresponding PSSCH reception, a base station or a sidelink transmitting terminal or a sidelink scheduler terminal may indicate whether to apply a set terminal specific PSFCH offset value. have.

Whether or not the UE-specific PSFCH offset is applied may be included in DCI or SCI for transmitting arbitrary PSSCH resource allocation information and may be indicated through PDCCH or PSCCH. In this case, according to an example, an information region for indicating whether a specific UE-specific PSFCH offset is applied may be included in a DCI format or SCI format including resource allocation information for the PSSCH.

Alternatively, according to another example, when transmitting DCI format or SCI format including PSSCH allocation information, an RNTI scrambled to CRC or a search space/coset in which DCI format or SCI format is transmitted (search space/CORESET) Or, as a function of the PSCCH resource pool, whether a specific UE-specific PSFCH offset is applied may be indicated.

Alternatively, according to another example, whether a specific UE-specific PSFCH offset is applied to a receiving terminal through higher layer signaling may be set to semi-static. Alternatively, whether to apply a UE-specific PSFCH offset through MAC CE signaling may be applied (activation) or deactivation (deactivation).

Referring to FIG. 14 again, the receiving terminal may transmit HARQ feedback information using the PSFCH resource (S1430).

The receiving terminal may transmit HARQ ACK/NACK feedback information for the received PSSCH using the determined PSFCH resource. In this case, the terminal may transmit HARQ ACK/NACK feedback information to the transmitting terminal transmitting the PSSCH or to the base station.

According to this, it is possible to provide a method and apparatus for transmitting sidelink HARQ feedback information capable of allocating radio resources for transmitting sidelink HARQ feedback information in NR.

15 is a diagram illustrating a procedure for a transmitting terminal to receive sidelink HARQ feedback information according to an embodiment.

Referring to FIG. 15, the transmitting terminal may transmit a physical sidelink shared channel (PSSCH) to the receiving terminal (S1500).

When the PSSCH is transmitted through the sidelink, the transmitting terminal may receive HARQ ACK/NACK feedback information corresponding to the transmitted PSSCH from the receiving terminal. That is, a PSFCH resource set or a PSFCH resource pool may be configured for transmission of HARQ ACK/NACK feedback information for PSSCH reception. The configuration information for the PSFCH resource set or the PSFCH resource pool may be composed of time period resource allocation information and frequency resource allocation information.

The PSFCH resource set or PSFCH resource pool configuration information may be set by a base station through cell-specific or UE-specific higher layer signaling, or may be pre-configured. have. Alternatively, the PSFCH resource set or PSFCH resource pool configuration information may be set by a transmitting terminal or a scheduler terminal, and transmitted to a receiving terminal through a sidelink wireless channel such as PSDCH, PSCCH or PSSCH.

That is, according to an example, when the PSFCH resource set or the PSFCH resource pool configuration information is set and transmitted by the transmitting terminal, in FIG. 15, the transmitting terminal includes a physical sidelink feedback channel (PSFCH) resource set It may further include the step of transmitting the configuration information for.

According to an example, the PSFCH resource pool may be configured as a form independent of PSCCH or PSSCH resource pool configuration. In this case, RRC parameters for the PSFCH resource pool are set separately from RRC parameters for PSCCH/PSSCH resource pool configuration, and can be explicitly set through higher layer signaling. However, this is an example, and is not limited thereto, and RRC parameters for the PSFCH resource pool may be configured in advance.

Alternatively, according to another example, the PSFCH resource pool may be configured in association with the PSCCH or PSSCH resource pool configuration. In this case, any PSCCH or PSSCH resource pool configuration information may include configuration information for the associated PSFCH resource pool. That is, the arbitrary PSCCH or PSSCH resource pool configuration information may include slot allocation information for indicating time period resource allocation information of the corresponding resource pool. Specifically, period setting information and slot offset information for sidelink slot allocation in which a PSSCH or PSSCH resource pool is configured may be included.

In this case, as configuration information for the PSFCH resource pool, timing gap related information may be included between a sidelink slot in which each PSSCH or PSCCH resource pool is configured and a sidelink slot in which a PSFCH resource pool corresponding to the corresponding slot is configured. According to an example, when a 1:1 mapping relationship between a sidelink slot in which a PSSCH resource pool is configured and a sidelink slot in which a PSFCH resource pool is configured is established, corresponding timing gap setting information is a direct slot gap between the PSSCH and the PSFCH. gap) information. That is, when the corresponding timing gap setting value is an arbitrary K value, when the terminal receives the PSSCH in any slot #n, through the PSFCH resource pool of slot #(n+K) after the K slot, which is the timing gap setting value, HARQ ACK/NACK feedback may be transmitted.

Or, when a mapping relationship of N:1 (an integer of N>1) between the sidelink slots in which the PSFCH resource pool is configured and the PSF resource pool is configured is established, a timing gap between the PSFCH resource pools associated with the PSSCH resource pool is established. The setting information may be minimum slot gap information required. That is, when the corresponding timing gap setting value is an arbitrary M value, the UE that has received the PSSCH from an arbitrary UE corresponds through the first PSFCH resource pool after the minimum M slot from the corresponding slot for HARQ ACK/NACK feedback for this. HARQ ACK/NACK feedback information may be transmitted. That is, when the PSFCH resource pool is configured with N sidelink slots for the sidelink slots in which the PSCCH/PSSCH resource pool is configured, the M value together with the corresponding N value is set through higher layer signaling, Or, it may be pre-configured or an arbitrary M value may be defined as a function of the corresponding N value.

In this case, when the UE receives the PSSCH in any slot #n, it may transmit HARQ ACK/NACK feedback through the PSFCH resource pool in slot #(n+M). Alternatively, the terminal may transmit HARQ ACK/NACK feedback through the first PSFCH resource pool after slot #(n+M-1).

A PSFCH resource for HARQ ACK/NACK feedback for PSSCH reception of the receiving terminal may be allocated through the set PSFCH resource pool. At this time, the PSFCH resource allocation information in the PSFCH resource pool may be explicitly signaled or implicitly signaled.

Alternatively, a PSFCH resource set for HARQ ACK/NACK feedback for PSSCH reception of the receiving terminal may be set. The PSFCH resource set is configured by a base station and transmitted through cell-specific or UE-specific higher layer signaling, or is set by a transmitting terminal or a scheduler terminal, PSDCH, PSCCH or It may be transmitted through a sidelink radio channel such as PSSCH.

A PSFCH resource for HARQ ACK/NACK feedback for PSSCH reception of any UE may be allocated through the set PSFCH resource set. At this time, the PSFCH resource allocation information in the PSFCH resource set may be explicitly signaled or implicitly signaled.

Referring back to FIG. 15, the transmitting terminal may receive HARQ feedback information for the PSSCH using the PSFCH resource determined by the receiving terminal based on predetermined identification information in the PSFCH resource set (S1510).

According to an example, a PSFCH resource to be used for HARQ ACK/NACK feedback for PSSCH reception at a receiving terminal among PSFCHs constituting a PSFCH resource pool or PSFCH resource set may be implicitly signaled. In this case, the receiving terminal can determine the PSFCH resource as a function of the sub-channel index (sub-channel index) for the sub-channel PSCCH or PSSCH transmission is made.

According to an example, when PSSCH transmission is performed based on groupcast, when a plurality of receiving terminals share one implicitly signaled PSFCH, PSFCH transmission resources for HARQ ACK/NACK feedback between the plurality of receiving terminals Collision can occur. In order to prevent such a collision, a UE-specific offset may be applied in allocating PSFCH resources for HARQ ACK/NACK feedback of the sidelink terminal. The receiving terminal may derive the final PSFCH resource for HARQ ACK/NACK feedback by applying each terminal specific offset value to the PSFCH resource information implicitly signaled by the base station or the sidelink transmitting terminal or the sidelink scheduling terminal.

According to an example, the UE-specific PSFCH offset value may be set by a base station for each UE through UE-specific upper layer signaling, MAC CE signaling, or L1 control signaling. Alternatively, when setting a group-cast session, a base station, a transmitting terminal, or a scheduler terminal may set a terminal-specific PSFCH offset value and transmit it to each receiving terminal. Or, when allocating a groupcast-based PSSCH resource, the base station, the transmitting terminal, or the scheduler terminal may transmit the UE-specific PSFCH offset value to each receiving terminal through the PDCCH or PSCCH.

Alternatively, the terminal-specific PSFCH offset value may be implicitly set as a function of each terminal ID or the like. For example, the UE-specific PSFCH offset value can be derived as a function of the C-RNTI of the UE. Alternatively, a terminal ID for sidelink transmission and reception is defined, and accordingly, a corresponding terminal specific PSFCH offset value may be derived. In this case, the terminal ID for transmitting and receiving the side link may be a terminal ID of a higher layer that is a group ID (member ID) for a group including a receiving terminal in group cast data transmission. Alternatively, the terminal ID may be in the form of a source ID as an identifier of a destination terminal or a destination ID that is a target of transmission of the corresponding unicast or groupcast data. Alternatively, the terminal ID for the corresponding sidelink transmission/reception may be a sidelink physical layer ID for receiving PSCCH, such as SL-RNTI.

The terminal ID for sidelink transmission/reception is set by the base station, allocated through terminal specific upper layer signaling, or set by the sidelink transmission terminal or sidelink scheduling terminal through a sidelink radio channel such as PSDCH, PSCCH or PSSSCH. Can be sent. Also, the groupcast PSSCH transmitting terminal may receive terminal specific PSFCH offset information for each sidelink receiving terminal. Specifically, the groupcast PSSCH transmitting terminal may receive terminal-specific PSFCH offset information for each receiving terminal through upper layer signaling or MAC CE signaling or L1 control signaling from the base station, or through a sidelink wireless channel from the scheduler terminal. have.

According to an example, in allocating a PSFCH resource for HARQ ACK/NACK feedback for PSSCH reception, whether to apply a UE-specific PSFCH offset may be additionally indicated. That is, in deriving a PSFCH resource for HARQ ACK/NACK feedback for a corresponding PSSCH reception, a base station or a sidelink transmitting terminal or a sidelink scheduler terminal may indicate whether to apply a set terminal specific PSFCH offset value.

Whether or not the UE-specific PSFCH offset is applied may be included in DCI or SCI for transmitting arbitrary PSSCH resource allocation information and may be indicated through PDCCH or PSCCH. In this case, according to an example, an information region for indicating whether a specific UE-specific PSFCH offset is applied may be included in a DCI format or SCI format including resource allocation information for the PSSCH.

Alternatively, according to another example, when transmitting DCI format or SCI format including PSSCH allocation information, an RNTI scrambled to CRC or a search space/coset in which DCI format or SCI format is transmitted (search space/CORESET) Or, as a function of the PSCCH resource pool, whether a specific UE-specific PSFCH offset is applied may be indicated.

Alternatively, according to another example, whether a specific UE-specific PSFCH offset is applied to a receiving terminal through higher layer signaling may be set to semi-static. Alternatively, whether to apply a UE-specific PSFCH offset through MAC CE signaling may be applied (activation) or deactivation (deactivation).

The transmitting terminal may receive HARQ ACK/NACK feedback information for the PSSCH from the receiving terminal using the PSFCH resource determined by the receiving terminal.

In the above, it has been described that HARQ ACK/NACK feedback information is received by the transmitting terminal, but the above can be applied in substantially the same manner even if the transmitting terminal transmitting the PSSCH is replaced with a base station, as long as there is no contradiction in technical spirit. have.

According to this, it is possible to provide a method and apparatus for transmitting sidelink HARQ feedback information capable of allocating radio resources for transmitting sidelink HARQ feedback information in NR.

Hereinafter, with reference to the related drawings, each embodiment related to configuration and allocation of radio resources for transmitting sidelink HARQ feedback information in the NR will be described in detail.

According to a sidelink transmission/reception method for providing a V2X service in an existing LTE system, data transmission through a sidelink was performed based on broadcast. That is, when a broadcast (broadcasting) a sidelink radio channel or a radio signal to be transmitted to neighboring terminals without specifying a destination terminal in any transmitter terminal, the corresponding broadcasting signal A sidelink communication in which a terminal capable of receiving a signal receives a corresponding signal has been made. Accordingly, in the case of LTE V2X, the HARQ procedure for PSSCH, which is a sidelink data channel, was not applied.

However, in the case of NR-based V2X, as well as the above-mentioned broadcast, a need has been raised for unicast or groupcast-based sidelink transmission/reception support.

As described above, when a sidelink transmission/reception method based on unicast or groupcast is defined as a form of NR-based V2X communication, a method for applying HARQ to a corresponding sidelink radio channel and a sidelink It is necessary to define a channel status information (CSI) acquisition method and a link adaptation method accordingly.

The present disclosure proposes a specific method for applying HARQ in data transmission and reception through a sidelink. In particular, when a groupcast through a sidelink is applied, a resource allocation method for transmitting HARQ ACK/NACK feedback information from a receiving terminal is proposed.

Previously defined Resource allocation for direct communication between terminals through a sidelink may be performed in a distributed manner or may be performed in a centralized manner. That is, within a resource pool configured or pre-configured by a base station, a transmitter node transmits, for example, a sub-channel for sidelink data transmission. ), and transmit a PSCCH including PSSCH and scheduling control information for the corresponding PSSCH. Or, the base station transmits sidelink resource allocation information for any transmitting terminal to the corresponding transmitting terminal through the PDCCH, and the transmitting terminal transmits the corresponding PSCCH and PSSCH through the sidelink resource allocated from the base station. Can transmit. As described above, as a method of transmitting wireless data through a sidelink, a transmission mode (transmissiom mode) 3 scheme scheduled by a base station and a distribution-based transmission mode (transmissiom mode) 4 are defined.

Similarly, for NR V2X, mode 1 in which PSSCH transmission resources are allocated by a base station and mode 2 allocated by a transmitting terminal or an arbitrary scheduler terminal may be defined. Accordingly, when a unicast method or a group cast method is supported as a sidelink transmission method for NR based V2X, one transmitter terminal and a corresponding receiver terminal(s), or one A unicast or groupcast link between the master terminal and the corresponding slave terminal(s) is configured, and the PSSCH transmission resource through the link is scheduled by the base station as above or scheduled by the terminal. Can.

When the unicast or groupcast type PSSCH transmission is performed, the terminal receiving the PSSCH may be defined to feedback HARQ ACK/NACK feedback information to the transmitting terminal or the scheduler terminal, or to the base station. . In this disclosure, a sidelink radio channel for corresponding HARQ ACK/NACK feedback may be referred to as PSFCH. However, this is not limited to the name, as an example, if the technical idea according to the present disclosure can be applied substantially the same.

This disclosure proposes a method for allocating a PSFCH resource for HARQ ACK/NACK feedback of a UE that has received a PSSCH through a side link. In particular, we propose a method for allocating PSFCH resources of UEs for groupcast-based PSSCH reception.

Embodiment 1. Configuration of PSFCH resource pool or PSFCH resource set

A PSFCH resource pool for HARQ ACK/NACK feedback on the PSSCH reception of the UE may be configured. The resource pool configuration information may be composed of time period resource allocation information and frequency resource allocation information, and may be configured by cell base stations through cell-specific or UE-specific higher layer signaling. It can be set or pre-configured. Alternatively, it may be set by a transmitting terminal or a scheduler terminal, and transmitted to a terminal through a sidelink wireless channel such as PSDCH, PSCCH or PSSCH.

Any PSFCH resource pool may be established in association with the PSSCH resource pool configuration. Alternatively, any PSFCH resource pool may be established in association with the PSCCH resource pool configuration.

PSFCH resource allocation for HARQ ACK/NACK feedback for PSSCH reception of any UE may be defined through a set PSFCH resource pool. At this time, the PSFCH resource allocation information in the corresponding PSFCH resource pool may be explicitly signaled or implicitly signaled.

The PSFCH resource set for HARQ ACK/NACK feedback for the UE's PSSCH reception may be set. The corresponding PSFCH resource set is configured by a base station and transmitted through cell-specific or UE-specific higher layer signaling, or is set by a transmitting terminal or a scheduler terminal and PSDCH, It may be transmitted through a sidelink radio channel such as PSCCH or PSSCH.

Through the set PSFCH resource set, PSFCH resource allocation for HARQ ACK/NACK feedback for PSSCH reception of any UE may be defined. At this time, the PSFCH resource allocation information in the corresponding PSFCH resource set may be explicitly signaled or implicitly signaled.

Embodiment 2. UE-specific offset configuration for groupcast (UE-specific offset configuration for groupcast)

As described above, the PSFCH resource to be used for HARQ ACK/NACK feedback for PSSCH reception in any of the PSFCHs constituting the above-described PSFCH resource pool or PSFCH resource set is a base station or sidelink transmission terminal or sidelink. The signaling may be explicitly signaled by the scheduling terminal or implicitly signaled. When explicitly signaled, it may be included in DCI or Sidelink Control Information (SCI) by the corresponding base station or sidelink transmission terminal or sidelink scheduling terminal and transmitted through PDCCH or PSCCH. When signaled implicitly, the PSFCH resource may be defined to be allocated as a function of a resource pool in which PSCCH or PSSCH transmission is performed or an index of a resource in which the PSCCH or PSSCH transmission is performed among the resource pools. For example, the resource index may include a sub-channel index, a sidelink control channel element index, or a basic unit of PSSCH or PSSCH transmission.

However, in the case of group-cast-based PSSCH transmission, collisions of PSFCH transmission resources for HARQ ACK/NACK feedback between a plurality of receiving terminals are performed because a plurality of receiving terminals share one explicitly or implicitly signaled PSFCH. This can happen.

To solve this, the present disclosure proposes a method of applying a UE-specific offset in allocating a PSFCH resource for HARQ ACK/NACK feedback of a sidelink terminal. Accordingly, each UE is allocated PSFCH resources for HARQ ACK/NACK feedback for arbitrary PSSCH reception, and PSFCH resources explicitly or implicitly signaled by a base station or sidelink transmission terminal or sidelink scheduling terminal It may be defined to derive a final PSFCH resource for HARQ ACK/NACK feedback based on this by applying each UE-specific offset value to the information.

For example, when the PSFCH resource allocation information for the UE is indicated through an ACK resource indicator (ARI) information area included in DCI or SCI that transmits scheduling information for the PSSCH, each UE is PSFCH resource by ARI indication It may be defined to derive the final PSFCH resource information by adding the UE-specific PSFCH offset value set for each terminal to the information (eg PSFCH index). Similarly, when PSFCH resource information is derived by an implicit method, it may be defined to include a UE-specific PSFCH offset value as a parameter of a corresponding implicit PSFCH resource derivation function.

The UE-specific PSFCH offset value may be set by a base station for each UE through UE-specific upper layer signaling or MAC CE signaling, or L1 control signaling. Alternatively, when a group-cast session is established, it may be set by a base station or a sidelink transmission terminal or a sidelink scheduler terminal and transmitted to each terminal. Or, when allocating a groupcast-based PSSCH resource, it may be transmitted to each terminal through PDCCH or PSCCH.

Alternatively, it may be set implicitly as a function of each terminal ID or the like. For example, it can be defined to be derived as a function of the C-RNTI of the terminal. Alternatively, a UE ID for sidelink transmission and reception may be defined, and accordingly, a UE-specific PSFCH offset value may be derived. In this case, the terminal ID for transmitting/receiving the sidelink may be a terminal ID of a higher layer, and may be in the form of a destination ID or a source ID, which is a target of the corresponding unicast or groupcast data transmission. Alternatively, the terminal ID for the corresponding sidelink transmission/reception may be a sidelink physical layer ID for receiving PSCCH, such as SL-RNTI.

The terminal ID for the corresponding sidelink transmission and reception is set by the base station, allocated through UE-specific upper layer signaling, or set by the sidelink transmission terminal or sidelink scheduling terminal, such as PSDCH, PSCCH or PSSSCH, etc. It can be transmitted over a sidelink wireless channel. Also, UE-specific PSFCH offset information for each sidelink receiving terminal may be transmitted to a groupcast PSSCH transmitting terminal. Specifically, UE-specific PSFCH offset information for each receiving terminal is transmitted to the groupcast PSSCH transmitting terminal through upper layer signaling or MAC CE signaling or L1 control signaling by the base station, or sidelink wireless by the scheduler terminal. It can be transmitted to the corresponding groupcast PSSCH transmitting terminal through the channel.

Additionally, in allocating a PSFCH resource for HARQ ACK/NACK feedback for arbitrary PSSCH reception, it may be defined to additionally indicate whether to introduce a set UE-specific PSFCH offset. That is, in deriving a PSFCH resource for HARQ ACK/NACK feedback for a corresponding PSSCH reception, an arbitrary PSSCH receiving terminal determines whether to apply a set UE-specific PSFCH offset value to a base station or sidelink transmitting terminal or sidelink. It can be defined to instruct the scheduler terminal.

Whether the UE-specific PSFCH offset is applied may be included in DCI or SCI for transmitting arbitrary PSSCH resource allocation information and may be indicated through PDCCH or PSCCH. Specifically, an information area for indicating whether a UE-specific PSFCH offset is applied to a DCI format or SCI format including resource allocation information for a PSSCH, for example, 1 bit By defining an indicator (1-bit indicator), it may be defined to explicitly indicate whether to apply a UE-specific PSFCH offset.

Alternatively, the RNTI scrambled to the CRC or the DCI format or SCI format transmitted when the DCI format or the SCI format including the PSSCH allocation information is transmitted without defining a separate indication information area or the corresponding DCI format or SCI format is transmitted. As a function of (search space/CORESET) or PSCCH resource pool, it may be defined to implicitly indicate whether to apply a UE-specific PSFCH offset.

Alternatively, it may be defined to set whether a UE-specific PSFCH offset is applied to semi-static through higher layer signaling for any UE. Alternatively, whether to apply the UE-specific PSFCH offset through MAC CE signaling may be defined to be applied (activation) or deactivation (deactivation).

Additionally, the above can be applied regardless of the specific PSFCH channel structure. For example, when the feedback information is directly transmitted to the terminal through the sidelink, the corresponding PSFCH may recycle the structure of the PSCCH or the structure of the PUCCH, or may be designed based on this or may be designed in a new form. It is not limited thereby. Similarly, when the feedback information is transmitted to the base station through the uu link, the corresponding PSFCH may recycle the structure of the PUCCH or be designed in a new form, and the present disclosure is not limited thereto.

According to this, it is possible to provide a method and apparatus for transmitting sidelink HARQ feedback information capable of allocating radio resources for transmitting sidelink HARQ feedback information in NR.

Hereinafter, a configuration of a receiving terminal and a transmitting terminal capable of performing some or all of the embodiments described with reference to FIGS. 1 to 15 will be described with reference to the drawings.

16 is a diagram showing the configuration of a receiving terminal 1600 according to another embodiment.

Referring to FIG. 16, the reception terminal 1600 according to another embodiment includes a reception unit 1610, a control unit 1620, and a transmission unit 1630.

The control unit 1610 controls the overall operation of the reception terminal 1600 according to a method in which the reception terminal required to perform the above-described present invention transmits HARQ feedback information. The transmitter 1620 transmits uplink control information and data and a message to a base station through a corresponding channel, and transmits sidelink control information and data and a message to a transmitting terminal or a sidelink scheduling terminal through a corresponding channel. The receiving unit 1630 receives downlink control information, data, and messages from a base station through a corresponding channel, and receives sidelink control information, data, and messages from a transmitting terminal or a sidelink scheduling terminal through a corresponding channel.

The receiver 1610 may receive configuration information for the PSFCH resource set. When the PSSCH is received through the sidelink, the transmitting unit 1620 of the receiving terminal may transmit HARQ ACK/NACK feedback information corresponding to the received PSSCH.

The PSFCH resource set or PSFCH resource pool configuration information may be set by a base station through cell-specific or terminal-specific higher layer signaling, or may be configured in advance. Alternatively, the receiving unit 1630 may receive the PSFCH resource set or PSFCH resource pool configuration information set by the transmitting terminal or the scheduler terminal through a sidelink wireless channel such as PSDCH, PSCCH or PSSCH.

According to an example, the PSFCH resource pool may be set in association with the PSCCH or PSSCH resource pool configuration. In this case, as configuration information for the PSFCH resource pool, timing gap related information may be included between a sidelink slot in which each PSSCH or PSCCH resource pool is configured and a sidelink slot in which a PSFCH resource pool corresponding to the corresponding slot is configured.

When a PSSCH is received from the transmitting terminal, the controller 1610 may determine the PSFCH resource used for transmission of HARQ feedback information for the PSSCH in the PSFCH resource set based on predetermined identification information. According to an example, a PSFCH resource to be used for HARQ ACK/NACK feedback for PSSCH reception at a receiving terminal among PSFCHs constituting a PSFCH resource pool or PSFCH resource set may be implicitly signaled. In this case, the control unit 1610 may determine the PSFCH resource as a function of a sub-channel index for a subchannel in which PSCCH or PSSCH transmission is performed.

According to an example, when PSSCH transmission is performed based on groupcast, when a plurality of receiving terminals share one implicitly signaled PSFCH, PSFCH transmission resources for HARQ ACK/NACK feedback between the plurality of receiving terminals Collision can occur. In order to prevent such a collision, a UE-specific offset may be applied in allocating PSFCH resources for HARQ ACK/NACK feedback of the sidelink terminal. The control unit 1610 can derive the final PSFCH resource for HARQ ACK/NACK feedback by applying each UE specific offset value to the PSFCH resource information implicitly signaled by the base station or sidelink transmission terminal or sidelink scheduling terminal. have.

According to an example, the terminal-specific PSFCH offset value may be implicitly set as a function of each terminal ID or the like. Alternatively, a terminal ID for sidelink transmission and reception may be defined, and accordingly, a terminal specific PSFCH offset value may be derived. In this case, the terminal ID for transmitting and receiving the side link may be a terminal ID of a higher layer that is a group ID (member ID) for a group including a receiving terminal in group cast data transmission. Alternatively, the terminal ID may be in the form of a source ID as an identifier of a destination terminal or a destination ID that is a target of transmission of the corresponding unicast or groupcast data. Alternatively, the terminal ID may be a sidelink physical layer ID, such as SL-RNTI, for PSCCH reception.

The terminal ID for sidelink transmission/reception is set by the base station, allocated through terminal specific upper layer signaling, or set by the sidelink transmission terminal or sidelink scheduling terminal through a sidelink radio channel such as PSDCH, PSCCH or PSSSCH. Can be sent. In addition, the terminal-specific PSFCH offset information for each sidelink receiving terminal may be transmitted to the groupcast PSSCH transmitting terminal. Specifically, the UE-specific PSFCH offset information for each receiving terminal is transmitted to the groupcast PSSCH transmitting terminal through upper layer signaling or MAC CE signaling or L1 control signaling by the base station, or the corresponding group through the sidelink radio channel by the scheduler terminal It may be transmitted to the cast PSSCH transmission terminal.

According to an example, in allocating a PSFCH resource for HARQ ACK/NACK feedback for PSSCH reception, whether to apply a UE-specific PSFCH offset may be additionally indicated. That is, in deriving the PSFCH resource for the HARQ ACK/NACK feedback for the corresponding PSSCH reception, the control unit 1610 may instruct the base station or the sidelink transmission terminal or the sidelink scheduler terminal to apply the set terminal specific PSFCH offset value. have.

Whether or not the UE-specific PSFCH offset is applied may be included in DCI or SCI for transmitting arbitrary PSSCH resource allocation information and may be indicated through PDCCH or PSCCH. In this case, according to an example, an information region for indicating whether a specific UE-specific PSFCH offset is applied may be included in a DCI format or an SCI format including resource allocation information for a PSSCH.

Alternatively, according to another example, when transmitting DCI format or SCI format including PSSCH allocation information, an RNTI scrambled to CRC or a search space/coset in which DCI format or SCI format is transmitted (search space/CORESET) Or, as a function of the PSCCH resource pool, whether a specific UE-specific PSFCH offset is applied may be indicated.

Alternatively, according to another example, whether a specific UE-specific PSFCH offset is applied to a receiving terminal through higher layer signaling may be set to semi-static. Alternatively, whether to apply a UE-specific PSFCH offset through MAC CE signaling may be applied (activation) or deactivation (deactivation).

The transmitter 1620 may transmit HARQ feedback information using PSFCH resources. The transmitter 1620 may transmit HARQ ACK/NACK feedback information for the received PSSCH using the determined PSFCH resource. In this case, the transmitter 1620 may transmit HARQ ACK/NACK feedback information to the transmitting terminal transmitting the PSSCH or to the base station.

According to this, it is possible to provide a method and apparatus for transmitting sidelink HARQ feedback information capable of allocating radio resources for transmitting sidelink HARQ feedback information in NR.

17 is a diagram showing the configuration of a transmitting terminal 1700 according to another embodiment.

Referring to FIG. 17, the transmission terminal 1700 according to another embodiment includes a control unit 1710, a transmission unit 1720, and a reception unit 1730.

The control unit 1710 controls the overall operation of the transmission terminal 1700 according to a method for a transmission terminal required to perform the above-described present invention to receive HARQ feedback information. The transmitting unit 1720 and the receiving unit 1730 are used to transmit and receive signals, messages, and data necessary to perform the present invention described above.

The transmitter 1720 may transmit the PSSCH to the receiving terminal. When the PSSCH is transmitted through the sidelink, the reception unit 1730 may receive HARQ ACK/NACK feedback information corresponding to the transmitted PSSCH from the receiving terminal. That is, a PSFCH resource set or a PSFCH resource pool may be configured for transmission of HARQ ACK/NACK feedback information for PSSCH reception.

The PSFCH resource set or PSFCH resource pool configuration information may be set by a base station through cell-specific or terminal-specific higher layer signaling, or may be configured in advance. Alternatively, the PSFCH resource set or PSFCH resource pool configuration information may be set by a transmitting terminal or a scheduler terminal, and transmitted to a receiving terminal through a sidelink wireless channel such as PSDCH, PSCCH or PSSCH.

That is, according to an example, when the PSFCH resource set or the PSFCH resource pool configuration information is set and transmitted by the transmitting terminal, in FIG. 15, the transmitting terminal includes a physical sidelink feedback channel (PSFCH) resource set It may further include the step of transmitting the configuration information for.

According to an example, the PSFCH resource pool may be set in association with the PSCCH or PSSCH resource pool configuration. In this case, as configuration information for the PSFCH resource pool, timing gap related information may be included between a sidelink slot in which each PSSCH or PSCCH resource pool is configured and a sidelink slot in which a PSFCH resource pool corresponding to the corresponding slot is configured.

The receiver 1730 may receive HARQ feedback information for the PSSCH using the PSFCH resource determined by the receiving terminal based on predetermined identification information in the PSFCH resource set.

When the PSSCH is transmitted from the transmitter 1720, the receiving terminal may determine the PSFCH resource used for transmission of HARQ feedback information for the PSSCH in the PSFCH resource set based on predetermined identification information. According to an example, a PSFCH resource to be used for HARQ ACK/NACK feedback for PSSCH reception at a receiving terminal among PSFCHs constituting a PSFCH resource pool or PSFCH resource set may be implicitly signaled. In this case, the receiving terminal can determine the PSFCH resource as a function of the sub-channel index (sub-channel index) for the sub-channel PSCCH or PSSCH transmission is made.

According to an example, when PSSCH transmission is performed based on groupcast, when a plurality of receiving terminals share one implicitly signaled PSFCH, PSFCH transmission resources for HARQ ACK/NACK feedback between the plurality of receiving terminals Collision can occur. In order to prevent such a collision, a UE-specific offset may be applied in allocating PSFCH resources for HARQ ACK/NACK feedback of the sidelink terminal. The receiving terminal may derive the final PSFCH resource for HARQ ACK/NACK feedback by applying each terminal specific offset value to the PSFCH resource information implicitly signaled by the base station or the sidelink transmitting terminal or the sidelink scheduling terminal.

According to an example, the terminal-specific PSFCH offset value may be implicitly set as a function of each terminal ID or the like. Alternatively, a terminal ID for sidelink transmission and reception may be defined, and accordingly, a terminal specific PSFCH offset value may be derived. In this case, the terminal ID for transmitting and receiving the side link may be a terminal ID of a higher layer that is a group ID (member ID) for a group including a receiving terminal in group cast data transmission. Alternatively, the terminal ID may be in the form of a source ID as an identifier of a destination terminal or a destination ID that is a target of transmission of the corresponding unicast or groupcast data. Alternatively, the terminal ID for the corresponding sidelink transmission/reception may be a sidelink physical layer ID for receiving PSCCH, such as SL-RNTI.

The terminal ID for sidelink transmission/reception is set by the base station, allocated through terminal specific upper layer signaling, or set by the sidelink transmission terminal or sidelink scheduling terminal through a sidelink radio channel such as PSDCH, PSCCH or PSSSCH. Can be sent. Also, the reception unit 1730 may receive terminal-specific PSFCH offset information for each sidelink receiving terminal. Specifically, the receiving unit 1730 may receive terminal-specific PSFCH offset information for each receiving terminal through upper layer signaling or MAC CE signaling or L1 control signaling from a base station, or through a sidelink wireless channel from a scheduler terminal. .

According to an example, in allocating a PSFCH resource for HARQ ACK/NACK feedback for PSSCH reception, whether to apply a UE-specific PSFCH offset may be additionally indicated. That is, in deriving a PSFCH resource for HARQ ACK/NACK feedback for a corresponding PSSCH reception, a base station or a sidelink transmitting terminal or a sidelink scheduler terminal may indicate whether to apply a set terminal specific PSFCH offset value.

Whether or not the UE-specific PSFCH offset is applied may be included in DCI or SCI for transmitting arbitrary PSSCH resource allocation information and may be indicated through PDCCH or PSCCH. In this case, according to an example, an information region for indicating whether a specific UE-specific PSFCH offset is applied may be included in a DCI format or SCI format including resource allocation information for the PSSCH.

Alternatively, according to another example, when transmitting DCI format or SCI format including PSSCH allocation information, an RNTI scrambled to CRC or a search space/coset in which DCI format or SCI format is transmitted (search space/CORESET) Or, as a function of the PSCCH resource pool, whether a specific UE-specific PSFCH offset is applied may be indicated.

Alternatively, according to another example, whether a specific UE-specific PSFCH offset is applied to a receiving terminal through higher layer signaling may be set to semi-static. Alternatively, whether to apply a UE-specific PSFCH offset through MAC CE signaling may be applied (activation) or deactivation (deactivation).

The reception unit 1730 may receive HARQ ACK/NACK feedback information for the PSSCH from the reception terminal by using the PSFCH resource determined by the reception terminal.

However, in the present disclosure, the description has been mainly focused on the transmitting terminal, but is not limited thereto. The foregoing can be applied to the sidelink scheduling terminal or the base station in substantially the same way, as long as it does not contradict the technical idea.

According to this, it is possible to provide a method and apparatus for transmitting sidelink HARQ feedback information capable of allocating radio resources for transmitting sidelink HARQ feedback information in NR.

The above-described embodiments can be supported by standard documents disclosed in at least one of the wireless access systems IEEE 802, 3GPP and 3GPP2. That is, steps, configurations, and parts that are not described in order to clearly reveal the technical idea among the embodiments may be supported by the above-described standard documents. In addition, all terms disclosed in this specification may be described by standard documents disclosed above.

The above-described embodiments may be implemented through various means. For example, the embodiments can be implemented by hardware, firmware, software, or a combination thereof.

For implementation by hardware, the method according to the embodiments includes one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), FPGAs (Field Programmable Gate Arrays), a processor, a controller, a microcontroller, or a microprocessor.

In the case of implementation by firmware or software, the method according to the embodiments may be implemented in the form of an apparatus, procedure, or function that performs the functions or operations described above. The software code can be stored in a memory unit and driven by a processor. The memory unit is located inside or outside the processor, and can exchange data with the processor by various known means.

In addition, the terms "system", "processor", "controller", "component", "module", "interface", "model", or "unit" described above generally refer to computer-related entity hardware, hardware and software. It can mean a combination of, software or running software. For example, the above-described components may be, but are not limited to, a process, processor, controller, control processor, entity, execution thread, program and/or computer driven by a processor. For example, both an application running on a controller or processor and a controller or processor can be components. One or more components can be in a process and/or thread of execution, and the components can be located on one device (eg, a system, computing device, etc.) or distributed across two or more devices.

The above description is merely illustrative of the technical idea of the present disclosure, and those skilled in the art to which the present disclosure pertains may make various modifications and variations without departing from the essential characteristics of the technical idea. In addition, the present embodiments are not intended to limit the technical spirit of the present disclosure, but to explain the scope of the technical spirit of the embodiments. The scope of protection of the present disclosure should be interpreted by the claims below, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present disclosure.

Claims (20)

In a method for a receiving terminal to transmit HARQ feedback information,
Receiving configuration information for a physical sidelink feedback channel (PSFCH) resource set;
Receiving a sidelink data channel (PSSCH) from a transmitting terminal;
Determining a PSFCH resource used for transmission of HARQ feedback information for the PSSCH in the PSFCH resource set based on predetermined identification information; And
And transmitting the HARQ feedback information using the PSFCH resource. According to claim 1,
The predetermined identification information,
And a sub-channel index for a sub-channel used to receive the PSSCH. According to claim 1,
The predetermined identification information,
A method including an identifier (source ID) of the transmitting terminal transmitting the PSSCH. According to claim 1,
The predetermined identification information,
And including the group identifier (member ID) of the receiving terminal receiving the PSSCH according to the groupcast (groupcast) transmission from the transmitting terminal. According to claim 1,
Configuration information for the PSFCH resource set,
And including timing gap information between reception of the PSSCH and transmission of the HARQ feedback information for reception of the PSSCH. In a method for a transmitting terminal to receive HARQ feedback information,
Transmitting a sidelink data channel (PSSCH) to a receiving terminal; And
And receiving HARQ feedback information for the PSSCH using a PSFCH resource determined based on predetermined identification information in a PSFCH resource set. The method of claim 6,
The predetermined identification information,
A method comprising a sub-channel index (sub-channel index) for the sub-channel used for the transmission of the PSSCH. The method of claim 6,
The predetermined identification information,
A method including an identifier (source ID) of the transmitting terminal transmitting the PSSCH. The method of claim 6,
The predetermined identification information,
And including the group identifier (member ID) of the receiving terminal receiving the PSSCH according to the groupcast (groupcast) transmission from the transmitting terminal. The method of claim 6,
Configuration information for the PSFCH resource set,
And including timing gap information between reception of the PSSCH and transmission of the HARQ feedback information for reception of the PSSCH. In the receiving terminal for transmitting the HARQ feedback information,
A receiver configured to receive configuration information for a physical sidelink feedback channel (PSFCH) resource set and receive a sidelink data channel (PSSCH) from a transmitting terminal;
A control unit determining a PSFCH resource used for transmission of HARQ feedback information for the PSSCH in the PSFCH resource set based on predetermined identification information; And
A terminal including a transmitter for transmitting the HARQ feedback information using the PSFCH resource. The method of claim 11,
The predetermined identification information,
A terminal including a sub-channel index (sub-channel index) for the sub-channel used to receive the PSSCH. The method of claim 11,
The predetermined identification information,
A terminal including an identifier (source ID) of the transmitting terminal transmitting the PSSCH. The method of claim 11,
The predetermined identification information,
A terminal including a group identifier (member ID) of the receiving terminal receiving the PSSCH according to a groupcast (groupcast) transmission from the transmitting terminal. The method of claim 11,
Configuration information for the PSFCH resource set,
A terminal including timing gap information between reception of the PSSCH and transmission of the HARQ feedback information for reception of the PSSCH. In the transmitting terminal receiving the HARQ feedback information,
A transmitter that transmits a sidelink data channel (PSSCH) to a receiving terminal; And
A terminal including a receiver configured to receive HARQ feedback information for the PSSCH using a PSFCH resource determined based on predetermined identification information in a PSFCH resource set. The method of claim 16,
The predetermined identification information,
A terminal including a sub-channel index (sub-channel index) for the sub-channel used for the transmission of the PSSCH. The method of claim 16,
The predetermined identification information,
A terminal including an identifier (source ID) of the transmitting terminal transmitting the PSSCH. The method of claim 16,
The predetermined identification information,
A terminal including a group identifier (member ID) of the receiving terminal receiving the PSSCH according to a groupcast (groupcast) transmission from the transmitting terminal. The method of claim 16,
Configuration information for the PSFCH resource set,
A terminal including timing gap information between reception of the PSSCH and transmission of the HARQ feedback information for reception of the PSSCH.

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