KR20220103620A - Method and apparatus for transmitting and receiving coordination information for sidelink communication - Google Patents

Abstract

The present embodiments relate to a method for transmitting and receiving coordination information for sidelink communication, and a device thereof. The method comprises the following steps of: enabling transmission and reception of coordination information between terminals; configuring coordination information including a preferred resource or a non-preferred resource set for a transmitting terminal or including resource conflict information; and transmitting the coordination information.

Description

Method and apparatus for transmitting and receiving coordination information for sidelink communication

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

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 for NR (New Radio) Design of a frame structure, channel coding & modulation, waveform & multiple access scheme, and the like is in progress. NR is required to be designed to satisfy various QoS requirements required for each segmented and detailed usage scenario as well as an improved data rate compared to LTE.

As representative usage scenarios of NR, eMBB (enhancement Mobile BroadBand), mMTC (massive machine type communication), and URLLC (Ultra Reliable and Low Latency Communications) have been defined. design is required.

Since each service requirement (usage scenario) has different requirements for data rates, latency, reliability, coverage, etc., through the frequency band constituting an arbitrary NR system As a method for efficiently satisfying the needs of each usage scenario, different numerology (eg, subcarrier spacing, subframe, Transmission Time Interval (TTI), etc.) based There is a need for a method for efficiently multiplexing a radio resource unit of .

As a part of this aspect, in NR sidelink communication using a sidelink, which is a radio link between terminals for providing V2X service in NR, when multiple terminals perform sidelink communication, in particular, the base station is a radio resource In the case of a communication mode that does not schedule , a design for efficiently using radio resources for sidelink communication without collision is required.

Embodiments of the present disclosure may provide a method and apparatus for transmitting and receiving coordination information for sidelink communication in NR.

In one aspect, the present embodiments provide a method for a receiving terminal to transmit coordination information, the step of enabling transmission and reception of coordination information between terminals, a preferred resource or a non-preferred resource for the transmitting terminal It is possible to provide a method including a step of configuring coordination information including a (non-preferred) resource set or including resource conflict information and transmitting the coordination information.

In another aspect, the present embodiments provide a method for a transmitting terminal to receive coordination information, the step of enabling transmission and reception of coordination information between terminals and a preferred resource or non-preferred resource for the transmitting terminal A method including receiving coordination information including a (non-preferred) resource set or resource conflict information from a receiving terminal may be provided.

In another aspect, the present embodiments enable transmission and reception of coordination information between terminals in a receiving terminal transmitting coordination information, and a preferred resource or non-preferred resource for the transmitting terminal -preferred) It is possible to provide a terminal including a control unit for configuring coordination information including a resource set or resource conflict information and a transmitter for transmitting the coordination information.

In another aspect, the present embodiments in the transmitting terminal receiving the coordination information (coordination information), the control unit for enabling transmission and reception of the coordination information between the terminals and a preferred (preferred) resource or a non-preferred resource for the transmitting terminal ( It is possible to provide a terminal including a receiving unit for receiving coordination information including a non-preferred resource set or including resource conflict information from a receiving terminal.

According to the present embodiments, it is possible to provide a method and apparatus for transmitting and receiving coordination information for sidelink communication in NR.

1 is a diagram schematically illustrating a structure of an NR wireless communication system to which this embodiment can be applied.
2 is a diagram for explaining a frame structure in an NR system to which this embodiment can be applied.
3 is a diagram for explaining a resource grid supported by a radio access technology to which this embodiment can be applied.
4 is a diagram for explaining a bandwidth part supported by a radio access technology to which the present embodiment can be applied.
5 is a diagram exemplarily illustrating 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 this embodiment can be applied.
7 is a diagram for explaining CORESET.
8 is a diagram for explaining various scenarios for V2X communication.
9 shows an example of UE1 (UE1) and UE2 (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 this 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 in which a receiving terminal transmits coordination information according to an embodiment.
15 is a diagram illustrating a procedure for a transmitting terminal to receive coordination information according to an embodiment.
16 is a diagram for explaining an operation of transmitting and receiving coordination information in sidelink communication according to the present embodiment.
17 is a diagram showing the configuration of a receiving terminal according to another embodiment.
18 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 components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present embodiments, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present technical idea, the detailed description may be omitted. When "includes", "having", "consisting of", etc. mentioned in this specification are used, other parts may be added unless "only" is used. When a component is expressed in a singular, it may include a case in which the plural is included unless otherwise explicitly stated.

In addition, in describing the components of the present disclosure, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms.

In the description of the positional relationship of components, when two or more components are described as being "connected", "combined" or "connected", two or more components are directly "connected", "coupled" or "connected" It should be understood that, however, two or more components and other components may be further “interposed” and “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 the temporal flow relation related to the components, the operation method or the manufacturing method, for example, the temporal precedence relationship such as "after", "after", "after", "before", etc. Alternatively, when a flow precedence relationship is described, it may include a case where it is not continuous unless "immediately" or "directly" is used.

On the other hand, when numerical values or corresponding information (eg, level, etc.) for a component are mentioned, even if there is no explicit description separately, the numerical value or the corresponding information is based on various factors (eg, process factors, internal or external shock, It may be interpreted as including an error range that may be caused by noise, etc.).

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

The present embodiments disclosed below may be applied to a wireless communication system using various wireless access technologies. For example, the present embodiments are CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access) Alternatively, it may be applied to various radio access technologies such as non-orthogonal multiple access (NOMA). In addition, the wireless 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 a radio technology such as global system for mobile communications (GSM)/general packet radio service (GPRS)/enhanced datarates for GSM evolution (EDGE). OFDMA may be implemented with a wireless technology such as 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 the universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is a part of evolved UMTS (E-UMTS) that uses evolved-UMTSterrestrial radio access (E-UTRA), and employs OFDMA in downlink and SC- in uplink FDMA is employed. As such, the present embodiments may be applied to currently disclosed or commercialized radio access technologies, or may be applied to radio access technologies currently under development or to be developed in the future.

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

A base station or cell of the present specification refers to an end that communicates with a terminal in terms of a network, a Node-B (Node-B), an evolved Node-B (eNB), gNode-B (gNB), a Low Power Node (LPN), Sector, site, various types of antennas, base transceiver system (BTS), access point, point (eg, transmission point, reception point, transmission/reception point), relay node (Relay Node) ), mega cell, macro cell, micro cell, pico cell, femto cell, RRH (Remote Radio Head), RU (Radio Unit), small cell (small cell), etc. In addition, the cell may mean including a BWP (Bandwidth Part) in the frequency domain. For example, the serving cell may mean the Activation BWP of the UE.

In the various cells listed above, since there is a base station controlling one or more cells, the base station can be interpreted in two ways. 1) in relation to the radio area, it may be the device itself providing a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, or a small cell, or 2) may indicate the radio area itself. In 1), the devices providing a predetermined radio area are controlled by the same entity, or all devices interacting to form a radio area cooperatively are directed to the base station. A point, a transmission/reception point, a transmission point, a reception point, etc. become an embodiment of a base station according to a configuration method of a wireless area. In 2), the radio area itself in which the signal is received or transmitted from the point of view of the user terminal or the neighboring base station may be indicated to the base station.

In the present specification, a cell is a component carrier having a coverage of a signal transmitted from a transmission/reception point or a coverage of a signal transmitted from a transmission/reception point (transmission point or transmission/reception point), and the transmission/reception point itself. can

Uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data by a terminal to a base station, and downlink (Downlink, DL, or downlink) refers to a method for transmitting and receiving data to and from a terminal by a base station do. A downlink may mean a communication or communication path from a multi-transmission/reception point to a terminal, and an uplink may mean a communication or communication path from the terminal to a multi-transmission/reception point. In this case, 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 multi-transmission/reception point.

The uplink and the downlink transmit and receive control information through a control channel such as a Physical Downlink Control CHannel (PDCCH), a Physical Uplink Control CHannel (PUCCH), etc., and a Physical Downlink Shared CHannel (PDSCH), a Physical Uplink Shared CHannel (PUSCH), etc Data is transmitted and received by configuring the same data channel. Hereinafter, a situation in which signals are transmitted/received through channels such as PUCCH, PUSCH, PDCCH and PDSCH may be expressed in the form of 'transmitting and receiving PUCCH, PUSCH, PDCCH and PDSCH'.

For clarity of explanation, the present technical idea is mainly described below for a 3GPP LTE/LTE-A/NR (New RAT) communication system, but the present technical features are not limited to the corresponding communication system.

In 3GPP, after research on 4G (4th-Generation) communication technology, 5G (5th-Generation) communication technology is developed to meet the requirements of ITU-R's next-generation wireless access technology. Specifically, 3GPP develops LTE-A pro, which improved LTE-Advanced technology to meet the requirements of ITU-R as a 5G communication technology, and a new NR communication technology separate from 4G communication technology. LTE-A pro and NR both refer to 5G communication technology. Hereinafter, 5G communication technology will be described with a focus on NR unless a specific communication technology is specified.

In the NR operation scenario, various operation scenarios were defined by adding consideration of satellites, automobiles, and new verticals to the existing 4G LTE scenarios. It is deployed in a range and supports the mMTC (Massive Machine Communication) scenario that requires a low data rate and asynchronous access, and the URLLC (Ultra Reliability and Low Latency) scenario that requires high responsiveness and reliability and supports high-speed mobility. .

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

<Normal NR system>

1 is a diagram schematically illustrating a structure of an NR system to which this embodiment can be applied.

1, the NR system is divided into a 5G Core Network (5GC) and an NR-RAN part, and the NG-RAN controls the user plane (SDAP/PDCP/RLC/MAC/PHY) and UE (User Equipment) It consists of gNBs and ng-eNBs that provide planar (RRC) protocol termination. gNB interconnection or gNB and ng-eNB interconnect via Xn interface. gNB and ng-eNB are each connected to 5GC through the NG interface. The 5GC may include an Access and Mobility Management Function (AMF) in charge of a control plane such as terminal access and mobility control functions and a User Plane Function (UPF) in charge of a control function for user data. NR includes support for both the frequency band below 6 GHz (FR1, Frequency Range 1) and the frequency band above 6 GHz (FR2, Frequency Range 2).

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

<NR Waveform, Pneumologic 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 MIMO (Multiple Input Multiple Output), and has advantages of using a low-complexity receiver with high frequency efficiency.

Meanwhile, in NR, since the requirements for data rate, delay rate, coverage, etc. are different for each of the three scenarios described above, it is necessary to efficiently satisfy the requirements for each scenario through the 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, NR transmission numerology is determined based on 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. is changed negatively.

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, NR pneumatology can be divided into five types according to the subcarrier spacing. This is different from the fact that the subcarrier interval of LTE, which is one of the 4G communication technologies, is fixed to 15 kHz. Specifically, subcarrier intervals used for data transmission in NR are 15, 30, 60, and 120 kHz, and subcarrier intervals used for synchronization signal transmission are 15, 30, 12, and 240 kHz. In addition, the extended CP is applied only to the 60 kHz subcarrier interval. On the other hand, as for the frame structure in NR, a frame having a length of 10 ms is defined, which is composed of 10 subframes having the same length of 1 ms. One frame can be divided into half frames of 5 ms, and each half frame includes 5 subframes. In the case of a 15 kHz subcarrier interval, one subframe consists of one slot, and each slot consists of 14 OFDM symbols. 2 is a diagram for explaining a frame structure in an NR system to which this 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 according to a subcarrier interval. For example, in the case of a numerology having a 15 kHz subcarrier interval, the slot is 1 ms long and is configured with the same length as the subframe. On the other hand, in the case of numerology having a 30 kHz subcarrier interval, a slot consists of 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms. That is, the subframe and the frame are defined to have 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, NR defines a basic unit of scheduling as a slot, and also introduces a mini-slot (or a sub-slot or a non-slot based schedule) in order to reduce transmission delay in a radio section. When a wide subcarrier interval is used, the length of one slot is shortened in inverse proportion, so that transmission delay in a radio section can be reduced. The mini-slot (or sub-slot) is for efficient support of the URLLC scenario and can be scheduled in units of 2, 4, or 7 symbols.

Also, unlike LTE, NR defines uplink and downlink resource allocation at a symbol level within one slot. In order to reduce the HARQ delay, a slot structure capable of transmitting HARQ ACK/NACK directly within a transmission slot has been defined, and this slot structure will be described 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 constituting an FDD or TDD frame 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 transmission is scheduled to be distributed in 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 the slot format by indicating the index of the table configured through UE-specific RRC signaling using SFI, and may indicate dynamically through Downlink Control Information (DCI) or statically or through RRC. It can also be ordered quasi-statically.

<NR Physical Resources>

In relation to a physical resource in NR, an antenna port, a resource grid, a resource element, a resource block, a bandwidth part, etc. are considered do.

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

3 is a diagram for explaining a resource grid supported by a radio access technology to which this embodiment can be applied.

Referring to FIG. 3 , in the resource grid, since the NR supports a plurality of numerologies on the same carrier, a resource grid may exist according to each numerology. In addition, the resource grid may exist according to an antenna port, a subcarrier interval, and a transmission direction.

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

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

In NR, unlike LTE in which the carrier bandwidth is fixed at 20Mhz, 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 NR, as shown in FIG. 4 , a bandwidth part (BWP) may be designated within the carrier bandwidth and used by the terminal. In addition, the bandwidth part is associated with one neurology and is composed of a subset of continuous common resource blocks, and may be dynamically activated according to time. A maximum of four bandwidth parts are configured in the terminal, respectively, in uplink and downlink, and data is transmitted/received using the bandwidth part activated at a given time.

In the case of a paired spectrum, the uplink and downlink bandwidth parts are set independently, and in the case of an unpaired spectrum, to prevent unnecessary frequency re-tunning between downlink and uplink operations For this purpose, the downlink and uplink bandwidth parts are set in pairs to share a center frequency.

<NR Initial Connection>

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

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

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

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

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

SSB can be transmitted up to 64 times in 5ms. A plurality of SSBs are transmitted using different transmission beams within 5 ms, and the UE performs detection on the assumption that SSBs are transmitted every 20 ms when viewed based on one specific 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 4 SSB beams can be transmitted in 3 GHz or less, and SSB can be transmitted using up to 8 different beams in a frequency band of 3 to 6 GHz and up to 64 different beams in a frequency band of 6 GHz or more.

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

On the other hand, 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 in a place other than the center of the system band, and a plurality of SSBs may be transmitted in the frequency domain when broadband operation is supported. Accordingly, the UE monitors the SSB using a synchronization raster that is a candidate frequency location for monitoring the SSB. The carrier raster and synchronization raster, which are 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, so that it can support fast SSB search of the terminal. can

The UE may acquire the MIB through the PBCH of the SSB. MIB (Master Information Block) includes minimum information for the terminal to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, the PBCH includes information on the position of the first DM-RS symbol in the time domain, information for the UE to monitor SIB1 (eg, SIB1 neurology information, information related to SIB1 CORESET, search space information, PDCCH related parameter information), 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 neurology information is equally applied to some messages used in the random access procedure for accessing the base station after the UE completes the cell search procedure. For example, the neurology information of SIB1 may be applied to at least one of messages 1 to 4 for the random access procedure.

The aforementioned RMSI may mean System Information Block 1 (SIB1), and SIB1 is periodically broadcast (eg, 160 ms) in the cell. SIB1 includes information necessary for the UE to perform an initial random access procedure, and is periodically transmitted through the PDSCH. In order for the UE to receive SIB1, it must receive neurology information used for SIB1 transmission and CORESET (Control Resource Set) information used for scheduling SIB1 through the PBCH. The UE checks scheduling information for SIB1 by using SI-RNTI in CORESET, and acquires SIB1 on PDSCH according to the scheduling information. SIBs other than SIB1 may be transmitted periodically or may be transmitted according to the request of the UE.

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

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

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), a UL grant (uplink radio resource), a temporary C-RNTI (Temporary Cell - Radio Network Temporary Identifier), and a Time Alignment Command (TAC). Since one random access response may include random access response information for one or more UEs, the random access preamble identifier may be included to inform which UE 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, RA-RNTI (Random Access - Radio Network Temporary Identifier).

Upon receiving the valid random access response, the terminal processes information included in the random access response and performs scheduled transmission to the base station. For example, the UE applies the TAC and stores the temporary C-RNTI. In addition, data stored in the buffer of the terminal or newly generated data is transmitted to the base station by using the UL grant. In this case, information for 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), transmit power control (TPC) information, etc. .

In this way, NR introduced the concept of CORESET in order to secure the flexibility of the system. 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. Quasi CoLocation (QCL) assumptions for each CORESET are set, and this is used for the purpose of notifying the characteristics of the analog beam direction in addition to the delay spread, Doppler spread, Doppler shift, and average delay, which are characteristics assumed by the conventional QCL.

7 is a diagram for explaining CORESET.

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

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 terminal may receive and configure one or more pieces of CORESET information through RRC signaling.

<LTE side link>

In the existing LTE system, a radio channel and radio protocol design for direct communication (ie, sidelink) between terminals to provide direct communication between terminals and V2X (especially V2V) service has been made.

With respect to the sidelink, PSSS/SSSS, which is a synchronization signal for synchronization between a wireless sidelink transmitter and a receiver, and a related sidelink MIB (Physical Sidelink Broadcasting Channel) for transmission and reception are defined, and also discovery information PSDCH (Physical Sidelink Discovery channel) for transmission and reception, PSCCH (Physical Sidelink Control Channel) for transmission and reception of SCI (Sidelink Control Information), and PSSCH (Physical Sidelink Shared Channel) for transmitting and receiving sidelink data were designed.

In addition, for radio resource allocation for the sidelink, the technology was developed by dividing it 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 pool. In addition, additional technological evolution was required in order to satisfy the V2X scenario in the LTE system.

In this environment, 3GPP derived 27 service scenarios related to vehicle recognition from Rel-14 and determined the main performance requirements according to road conditions. In addition, in recent Rel-15, 25 more advanced service scenarios such as platooning, advanced driving, and long-distance vehicle sensors were derived and 6 performance requirements were determined.

In order to satisfy these performance requirements, technology development has been carried out to improve the performance of the sidelink technology developed based on the conventional D2D communication according to the requirements of V2X. In particular, for application to C-V2X (Cellular-V2X), a technology for improving the physical layer design of a sidelink to be suitable for a high-speed environment, a resource allocation technology, and a synchronization technology can be selected as major research technologies.

The sidelink described below means a link used for D2D communication developed after 3GPP Rel-12 and V2X communication after Rel-14, and each channel term, synchronization term, resource term, etc. is a D2D communication requirement, V2X Regardless of the requirements of Rel-14, 15, they are described in the same terms. However, for convenience of understanding, the difference between sidelinks satisfying the V2X scenario requirements will be mainly described based on the sidelinks for D2D communication in Rel-12/13 as needed. Therefore, the terms related to sidelink described below are only used to describe D2D communication/V2X communication/C-V2X communication separately for comparison difference and convenience of understanding, and are not limitedly applied to a specific scenario.

<Resource Allocation>

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

Referring to FIG. 8 , a V2X terminal (represented as a vehicle, but can be set in various ways such as a user terminal) may be located within the coverage of the base station (eNB or gNB or ng-eNB), or may be located outside the coverage of the base station. For example, communication may be performed between terminals within the coverage of the base station (UE N-1, UE G-1, UE X), and between terminals within the coverage of the base station and terminals outside (eg, 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 coverage of the base station.

In these various scenarios, in order for the corresponding terminal to perform communication using the sidelink, radio resource allocation for communication is required, and radio resource allocation is largely divided into a base station handling allocation and a method in which the terminal itself selects and allocates.

Specifically, in D2D, there are a centralized method in which the base station intervenes in resource selection and management (Mode 1) and a distributed method in which the terminal randomly selects preset resources (Mode 2). Similar to D2D, in C-V2X, there are 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 area and the DATA pool resource area allocated thereto to the transmitting terminal.

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

Referring to FIG. 9 , a base station is denoted as an eNB, but as described above, it may be a gNB or an ng-eNB. In addition, although a mobile phone is illustrated as an example, the terminal may be variously applied to a vehicle, an infrastructure device, and the like.

In FIG. 9A , the transmitting terminal UE1 may select a resource unit corresponding to a specific resource from a resource pool indicating a set of a series of resources, and transmit a sidelink signal using the resource unit. The receiving terminal UE2 may receive a resource pool configured to allow the UE1 to transmit a signal and detect a transmission signal of the corresponding terminal.

Here, the resource pool may be informed by the base station when the UE1 is within the connection range of the base station, and when outside the connection range of the base station, the resource pool may be notified by another terminal or may be determined as a predetermined resource. 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 to use for its own sidelink signal transmission.

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

Meanwhile, the resource pool may be subdivided into several types. First, it may be classified according to the contents of a sidelink signal transmitted from each resource pool. For example, the content of the sidelink signal may be divided, and a separate resource pool may 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.

SA provides information such as the location of resources used by the transmitting terminal for the transmission of the following sidelink data channel and other information such as modulation and coding scheme (MCS), MIMO transmission method, and timing advance (TA) necessary for demodulation of other data channels. It may be a signal including This signal may also 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 in which SA is multiplexed with sidelink data and transmitted.

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

On the other hand, when SA is multiplexed and transmitted together with sidelink data on the same resource unit, only a sidelink data channel of a type excluding SA information may be transmitted in 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 in which the transmitting terminal transmits information such as its ID so that the neighboring terminal can discover itself. Even when the content of the sidelink signal is the same, different resource pools may be used according to the transmission/reception property of the sidelink signal.

For example, even with the same sidelink data channel or discovery message, the transmission timing determining method of the sidelink signal (for example, whether it is transmitted at the reception time of the synchronization reference signal or transmitted by applying a certain TA) or the resource allocation method (For example, whether the base station designates individual signal transmission resources to individual transmitting terminals or whether individual transmitting terminals select individual signal transmission resources by themselves in the pool), signal format (eg, each sidelink signal has one sub It may be divided into different resource pools again according to the number of symbols occupied by a frame or the number of subframes used for transmission of one sidelink signal), signal strength from a base station, transmission power strength of a sidelink terminal, and the like.

<Synchronous 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 the sidelink must be performed. For this, it is important that the terminal located outside the coverage of the base station acquires synchronization.

Hereinafter, based on the above description, a method of synchronizing time and frequency in communication between vehicles, in particular between vehicles, between vehicles and other terminals, and between vehicles and an infrastructure network, in sidelink communication will be described.

D2D communication uses a sidelink synchronization signal (SLSS), which is a synchronization signal transmitted from a base station for time synchronization between terminals. In C-V2X, a Global Navigation Satellite System (GNSS) may be additionally considered to improve synchronization performance. However, priority may be given to synchronization establishment or the base station may indicate information on priority. For example, in determining its own transmission synchronization, the terminal preferentially selects a synchronization signal directly transmitted by the base station, and if it is located outside the coverage of the base station, preferentially synchronizes to the SLSS transmitted by the terminal within the coverage of the base station. it will match

On the other hand, since a wireless terminal installed in a vehicle or a terminal installed in a vehicle has relatively less battery consumption and can use satellite signals such as GPS for navigation purposes, time or frequency synchronization between terminals is set for satellite signals. can be used to Here, the satellite signal may correspond to a GNSS signal such as a Global Navigation Satellite System (GLONAS), GALILEO, and BEIDOU 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/modified/repeated to the PSS. Also, unlike DL PSS, other Zadoff Chu root indexes (eg, 26, 37) may be used. The SSSS may be an M-sequence or a structure similar to/modified/repeated with the SSS. If the terminals synchronize from the base station, the SRN becomes the base station and the SLSS becomes the PSS/SSS.

Unlike PSS/SSS of DL, PSSS/SSSS follows UL subcarrier mapping scheme. PSSCH (Physical Sidelink Synchronization Channel) is basic system information that the UE needs to know first before transmitting and receiving sidelink signals (eg, SLSS-related information, duplex mode (DM), TDD UL/DL configuration, resources Pool-related information, SLSS-related application type, subframe offset, broadcast information, etc.) may be transmitted through a channel. The PSSCH may be transmitted on the same subframe as the SLSS or on a subsequent subframe. DM-RS may be used for demodulation of PSSCH.

The SRN may be a node transmitting SLSS and PSSCH. The SLSS may be in the form of a specific sequence, and the PSSCH may be in the form of a sequence indicating specific information or a code word after undergoing 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 UE may be the SRN.

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

<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, NR frame structure, numerology, channel transmission/reception procedure, etc. are applied to enable flexible V2X service provision in more diverse environments. To this end, it is required to develop technologies such as a resource sharing technology between a base station and a terminal, a sidelink carrier aggregation (CA) technology, a partial sensing technology for a pedestrian terminal, and sTTI.

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

In addition, as it was decided to support HARQ for QOS, it was decided to include a HARQ process ID in the control information. In LTE HARQ, PUCCH for HARQ was transmitted 4 subframes after downlink transmission, but in NR HARQ, the feedback timing is, for example, in DCI format 1_0 or 1_1 PUCCH resource indicator (PUCCH resource indicator) or HARQ feedback for PDSCH PUCCH resources 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 in order to reduce system overhead, and the transmitting terminal can retransmit data once according to selection for data transmission safety. However, NR V2X may transmit HARQ ACK/NACK information in terms of data transmission stability, and in this case, overhead may be reduced by bundling and transmitting the corresponding 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 it, it may be bundled and transmitted through the PSCCH. Although it has been described that the HARA ACK/NACK is transmitted through the PSCCH in the drawing, it may be transmitted through a separate channel or another channel, and the bundled HARQ information may consist of 3 bits or less.

Meanwhile, in FR1 for the frequency domain below 3 GHz, 15 kHz, 30 kHz, 60 kHz, and 120 kHz were discussed as candidates for subcarrier spacing (SCS). In addition, for FR2 in the frequency region exceeding 3 GHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz as subcarrier spacing (SCS) were discussed as candidates. For NR V2X, a mini-slot (eg, 2/4/7 symbol) smaller than 14 symbols may be supported as a minimum scheduling unit.

As a candidate group for RS, DM-RS, PT-RS, CSI-RS, SRS, and AGC training signals were to be discussed.

The multiplexing of the PSSCH associated with the PSCCH will discuss the following four options as shown in FIG. 11 . Option 2 is similar to multiplexing of PSCCH and PSSCH in LTE V2X.

synchronization mechanism

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

resource allocation

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

Mode 4 may cover the following resource allocation sub-modes. That is, the UE automatically selects a sidelink resource for transmission, assists in selecting a sidelink resource for other UE(s), is configured with a configured grant for sidelink transmission, or a sidelink of another UE(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 mean resource(s) defined in advance so that the UE performs a V2X operation (or may perform a V2X operation). In this case, the resource pool may be defined, for example, in terms of time-frequency. On the other hand, the V2X transmission resource pool may exist in various types.

11 illustrates the type of V2X transmission resource pool.

Referring to Figure 11 (a), V2X transmission resource pool #A may be a resource pool that allows only (partial) sensing (sensing). The V2X transmission resource selected by (partial) sensing is semi-statically maintained at a certain period.

Referring to Figure 11 (b), V2X transmission resource pool #A may be a resource pool that allows only random selection (random selection). In the V2X transmission resource pool #B, the UE does not perform (partial) sensing, and may randomly select a V2X transmission resource in a selection window.

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

On the other hand, although not shown in FIG. 11, there may also exist a resource pool in which both (partial) sensing and random selection are possible. The base station may inform that it can select a V2X resource by one of (either of the partial sensing and the random selection) sensing and random selection.

In the present specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, or various messages related to NR (New Radio) in the present specification can be interpreted in various meanings used in the past or present or used in the future.

New Radio (NR)

Recently, NR conducted in 3GPP is designed to satisfy various QoS requirements required for each segmented and detailed service requirement (usage scenario) as well as an improved data rate compared to LTE. In particular, eMBB (enhancement Mobile BroadBand), mMTC (massive machine type communication), and URLLC (Ultra Reliable and Low Latency Communications) are defined as representative service requirements (usage scenario) of NR, and each service requirement (usage scenario) requires As a method to satisfy , a flexible frame structure design compared to LTE/LTE-Advanced is required.

Each service requirement (usage scenario) is a frequency constituting an arbitrary NR system because the requirements for data rates, latency, reliability, coverage, etc. are different from each other 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 requirement (usage scenario) through the band It is designed to efficiently multiplex the

As a method for this, TDM, FDM or TDM/FDM-based through one or a plurality of NR component carriers (s) for numerology with different subcarrier spacing values Discussion was made on a method of supporting by multiplexing to 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 reference numerology for defining the subframe duration is used. As a result, it was decided to define a single subframe duration composed of 14 OFDM symbols of the same 15 kHz Sub-Carrier Spacing (SCS)-based normal CP overhead as LTE. Accordingly, in NR, a subframe has a duration of 1 ms. However, unlike LTE, the NR subframe is an absolute reference time duration, and a slot and a mini-slot as a time unit that is the basis of actual up/downlink data scheduling. ) can be defined. In this case, the number of OFDM symbols constituting the corresponding slot, the y value, is determined to have a value of y=14 regardless of the SCS value in the case of a normal CP.

Accordingly, any slot consists of 14 symbols, and according to the transmission direction of the slot, all symbols are used for downlink transmission (DL transmission), or all symbols are used for uplink transmission (UL). transmission), or may be used in the form of a downlink portion (DL portion) + a gap + an uplink portion (UL portion).

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

In particular, in the case of transmission and reception of data critical to latency such as URLLC, 1ms (14 symbols) defined in a numerology-based frame structure with a small SCS value such as 15kHz When scheduling is performed in units of slots, it may be difficult to satisfy the latency requirement. For this purpose, a mini-slot composed of fewer OFDM symbols than the corresponding slot is defined, and based on this, it is critical to the same latency as the URLLC. It can be defined so that scheduling of (latency critical) data is performed.

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

As described above, in NR, by defining different SCS or different TTI lengths, a discussion is underway on a method of satisfying 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 CC (Component Carrier) was supported. That is, according to a frequency distribution scenario (deployment scenario), any LTE operator was able to configure a bandwidth of at least 1.4 MHz to a maximum of 20 MHz in configuring one LTE CC, and a normal LTE terminal is one LTE For CC, the transmit/receive capability of 20 MHz bandwidth was supported.

However, in the case of NR, the design is made to enable support for NR terminals having different transmission/reception bandwidth capabilities through one wideband NR CC. By configuring one or more bandwidth parts (BWP, bandwidth part(s)) composed of a segmented bandwidth for an arbitrary NR CC, flexible (bandwidth part configuration) and activation (activation) different for each terminal It is required to support a wider bandwidth operation that is flexible.

Specifically, in NR, one or more bandwidth parts may be configured through one serving cell configured from the viewpoint of the terminal, and the terminal may configure one downlink bandwidth part in the corresponding serving cell (serving cell). DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) are activated and defined to be used for uplink/downlink data transmission/reception. In addition, when a plurality of serving cells are configured in the corresponding terminal, that is, one downlink bandwidth part and/or uplink bandwidth part is activated for each serving cell even for a terminal to which CA is applied. Thus, it is defined to be used for uplink/downlink data transmission/reception by using the radio resource of the 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 terminal specific (UE) through dedicated RRC signaling for each terminal -specific) A bandwidth part(s) is configured, and a default bandwidth part for a fallback operation may be defined for each terminal.

However, a plurality of downlink and/or uplink bandwidth parts are activated and used at the same time according to the configuration of the terminal's capability and bandwidth part(s) in an arbitrary serving cell. However, in NR rel-15, it is defined to activate and use only one downlink bandwidth part (DL bandwidth part) and uplink bandwidth part (UL bandwidth part) at any time in any terminal. .

NR sidelink

In order to provide LTE and NR-based V2X service, a direct communication protocol design between terminals based on LTE or NR framework was made. In particular, the design of an NR sidelink-related radio communication protocol for direct communication between NR-based terminals is being worked on. The NR sidelink supports unicast and groupcast-based sidelink transmission in addition to the existing broadcast-based LTE sidelink transmission method. In addition, for this, the NR sidelink supports HARQ operation and CSI-based link adaptation.

Accordingly, related radio signals/channels designed in the existing LTE sidelink communication, that is, PSSS/SSSS, which is a synchronization signal for synchronization between a wireless sidelink transmitting end and a receiving end, and a related sidelink MIB (Master Information Block) PSBCH ( Physical Sidelink Broadcasting Channel) and SCI (Sidelink Control Information) including sidelink scheduling control information, PSCCH (Physical Sidelink Control Channel) for transmitting and receiving, and PSSCH (Physical Sidelink Shared Channel) for transmitting and receiving sidelink data. A Physical Sidelink Feedback Channel (PSFCH) for HARQ ACK/NACK feedback, which is sidelink feedback control information, was additionally designed. In addition, various HARQ ACK/NACK feedback methods based on unicast and groupcast were defined.

A change in the frame structure of a sidelink to be used for information transmission and reception in sidelink communication is also required according to a change in subcarrier spacing (SCS) of an OFDM communication system that is changed in NR.

The sidelink signal in this embodiment may use a CP-OFDM type waveform among the CP-OFDM type and the DFT-s-OFDM type. In addition, the sidelink may use the following subcarrier spacing (hereinafter, SCS). For example, in FR (frequecy range) 1 using a frequency band of less than 6 GHz, SCS of 15 kHz, 30 kHz, and 60 kHz is used. In FR 2, which uses a frequency band of 6 GHz or higher, 60 kHz and 120 kHz intervals are used, and the 60 kHz band can be mainly used.

In addition, the sidelink uses a cyclic prefix (CP) to prevent modulation that may occur in the wireless communication transmission/reception process, and the length may be set equal to the normal CP length of the NR Uu interface. If necessary, an extended CP may be applied.

In addition, when considering a scenario for sidelink communication, there is a possibility that a plurality of terminals may cluster and communicate within a certain range, such as when a plurality of vehicles perform group driving. In this case, a problem in which radio resources for sidelink communication frequently collide may occur. In particular, unlike Mode 1 in which the base station allocates and schedules sidelink communication resources, in Mode 2 in which the terminal selects a sidelink communication resource based on a sensing operation within a certain resource pool, resource collision and an adjustment procedure are required. can be

Hereinafter, a method of specifically transmitting and receiving coordination information for sidelink communication will be described with reference to related drawings.

In the present disclosure, a receiving terminal (Rx UE) means a terminal that receives a PSCCH and a corresponding PSSCH through a sidelink. In addition, a transmitting terminal (Tx UE) means a terminal transmitting a PSCCH and a corresponding PSSCH through a sidelink.

In addition, in the present disclosure, coordination information means information transmitted to solve a problem caused by overlapping radio resources in sidelink communication, and is not limited to the term, but coordination information and auxiliary information having the same meaning (assistance information) and the like may also be referred to as other terms.

14 is a diagram illustrating a procedure in which a receiving terminal transmits coordination information according to an embodiment.

Referring to FIG. 14 , a receiving terminal may enable transmission/reception of coordination information between terminals ( S1400 ).

As described above, in sidelink mode 2, since each terminal performs communication by allocating resources, a case in which resources overlap may occur. In this case, it is necessary to adjust resource allocation by sharing allocated resource information between terminals. That is, referring to FIG. 16 , a situation in which coordination between terminals is required through transmission and reception of coordination information in sidelink communication is illustrated.

For example, as in the situation 1000 at the top of FIG. 16 , in sidelink mode 2, UE1 and UE2 are out of a sensing range for radio resource selection, respectively, so that the same radio resource is selected for sidelink transmission to UE3. cases may occur. In this case, a collision does not occur in radio resource selection and data transmission, respectively, from the viewpoints of UE1 and UE2. However, since UE3 receives sidelink data from UE1 and UE2 through the same radio resource, a resource collision problem occurs. In order to solve such a hidden node problem, an inter-terminal coordination procedure may be required.

Alternatively, as in situation 1010 at the bottom of FIG. 16 , UE1 may transmit sidelink data to UE3, and UE3 may also transmit sidelink data to UE2. In this case, if UE1 and UE3 select the same sidelink radio resource, UE3 may not receive data transmitted by UE1 due to collision. As such, in order to solve the half duplex problem, an inter-terminal coordination procedure may be required.

In this way, when an inter-terminal coordination procedure is required, the receiving terminal may enable transmission/reception of coordination information between the terminals. In this case, according to an example, it is assumed that the receiving terminal and the transmitting terminal support the use of coordination information between the terminals.

However, according to another example, it may be required to confirm whether the receiving terminal and the transmitting terminal each support the use of coordination information between terminals. In this case, the method according to the present disclosure may further include, by the receiving terminal, transmitting capability information for the coordination information to the transmitting terminal, and receiving the capability information for the coordination information from the transmitting terminal. .

That is, whether coordination information is supported for each terminal may be transmitted between the base station and the terminal through capability signaling. Specifically, the capability information may be information related to whether transmission/reception is supported for the coordination information or the type or format of the supported coordination information.

When the receiving terminal and the transmitting terminal are terminals supporting transmission/reception of coordination information, transmission/reception of coordination information for sidelink communication may be enabled or disabled. According to an example, the receiving terminal may determine whether to enable transmission and reception of coordination information based on a cast type of sidelink transmission.

Alternatively, according to another example, the receiving terminal may determine whether to enable transmission and reception of coordination information based on explicit signaling. For example, whether to enable the corresponding enable may be set through higher layer signaling such as RRC signaling. Alternatively, whether to enable the corresponding enable may be indicated through the sidelink control information. Alternatively, whether to enable transmission and reception of coordination information may be implicitly set according to a preset condition, such as whether a specific SCI format is used.

Referring back to FIG. 14, the receiving terminal configures coordination information including a preferred resource or a non-preferred resource set for the transmitting terminal, or including resource conflict information. can be (S1410).

The receiving terminal may receive sidelink reservation resource information including radio resource information selected for sidelink transmission from the transmitting terminal. The sidelink reservation resource information may be transmitted while being included in the sidelink control information. Sidelink control information is transmitted through PSCCH and PSSCH. The sidelink reservation resource information may be transmitted through at least one channel of a PSCCH and a PSSCH.

The receiving terminal may configure coordination information based on the reserved resource information received from the transmitting terminal. According to an example, the receiving terminal may configure the coordination information when the request information for requesting the coordination information is received from the transmitting terminal. The request information from the transmitting terminal may be received by being included in the sidelink control information. In this case, the receiving terminal may configure coordination information including a preferred resource or a non-preferred resource set.

According to an example, the coordination information including the preferred resource or the non-preferred resource set may be configured based on the RSRP value for another transmitting terminal confirmed by the receiving terminal. The receiving terminal may select preferred resource set information based on sidelink reservation resource information of another transmitting terminal. Specifically, the selected at least one radio resource included in the preferred resource set information is sidelink reservation resource information having an RSRP measurement value greater than a preset threshold among sidelink reservation resource information reserved by at least one other transmitting terminal. may be configured to be excluded.

To this end, the receiving terminal may measure RSRP for at least one radio resource included in the sidelink reservation resource information received from at least one other transmitting terminal, respectively. The receiving terminal compares the RSRP value measured for each of at least one radio resource with a preset RSRP threshold. Thereafter, the receiving terminal configures the coordination information so that the reserved resources exceeding the threshold among the reserved resources of other transmitting terminals are not included in the preferred resource set information. This is because, when measured with an RSRP measurement value below a certain level, even if the radio resource overlaps with another transmitting terminal, the possibility of collision with the use of the transmitting terminal due to distance, blockage, etc. is low.

Alternatively, the receiving terminal may select the non-preferred resource set information based on sidelink reservation resource information of another transmitting terminal. Specifically, the non-preferred resource set information includes at least one radio resource determined based on the sidelink reservation resource information reserved by at least one other transmitting terminal that the receiving terminal receives and the RSRP measurement value measured by the receiving terminal. have. For example, the non-preferred resource set information may be determined based on an RSRP measurement value for at least one radio resource included in sidelink reservation resource information reserved by another transmitting terminal.

Similar to the preferred resource set information, for a reserved resource having an RSRP measurement value of a certain level or higher, the receiving terminal may configure it as coordination information. Alternatively, the receiving terminal may include, in the non-preferred resource set information, both a reserved resource reserved by another transmitting terminal and a radio resource having an RSRP measurement value of a predetermined level or higher measured by the receiving terminal.

According to another example, the coordination information including the resource collision information is configured based on whether there is overlap in the time domain or the frequency domain between the resource allocation to the other transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. can be When the radio resource indicated by the sidelink reservation resource information transmitted by the transmitting terminal overlaps with the sidelink reservation resource information reserved by at least one other transmitting terminal that the receiving terminal receives, at least part or all of the resource Coordination information including collision information may be configured.

The receiving terminal may determine whether the reserved resources of the transmitting terminal and the other transmitting terminal overlap by using the sidelink reservation resource information transmitted by the transmitting terminal and the sidelink reservation resource information transmitted by another terminal. When some or all overlap, the receiving terminal may configure coordination information including resource collision information indicating whether collision of sidelink reservation resource information transmitted by the transmitting terminal occurs.

Alternatively, the receiving terminal may configure the coordination information according to the comparison result between the sidelink reservation resource information transmitted by the transmitting terminal and the sidelink radio resource already used by another transmitting terminal for communication. That is, when the reserved resource of the transmitting terminal and the radio resource used by another transmitting terminal overlap at least a part or the whole, the receiving terminal may configure the coordination information.

Referring back to FIG. 14 , the receiving terminal may transmit coordination information (S1420).

According to an example, the receiving terminal transmits the configured coordination information using at least one channel of a sidelink control channel (PSCCH), a sidelink data channel (PSSCH), or a sidelink feedback channel (PSFCH) according to the type of coordination information. can For example, the first type coordination information regarding the preferred resource or the non-preferred resource resource set may be transmitted through at least one channel of the PSCCH and the PSSCH. In contrast, the second type coordination information regarding resource collision information may be transmitted through the PSFCH.

The receiving terminal may transmit the coordination information according to a transmission trigger condition of the coordination information. The transmission trigger condition may be set when explicit reporting request information is received from the transmitting terminal or a preset transmission period arrives. In this case, the coordination information may be configured to include preferred resource set information or non-preferred resource set information.

Alternatively, the transmission trigger condition may be set to a case in which an overlap in the time domain or frequency domain is detected between the resource allocation to another transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. In this case, the coordination information may be configured to include resource collision information.

The transmitting terminal may select or reselect a radio resource for sidelink communication based on the received coordination information.

According to an example, the transmitting terminal may select or reselect a sidelink resource based on the coordination information and the sensing result sensed in the sensing window. The sensing window means a time period for each terminal to select a radio resource to perform sidelink communication. Each terminal selects or reselects a specific radio resource in the resource pool by using the value of the radio resource sensing result sensed in the sensing window. Accordingly, the transmitting terminal may select or reselect a radio resource by using at least one of preferred resource set or non-preferred resource set information included in the received coordination information and resource information selected as a result of sensing.

When preferred resource set information is included in the coordination information, the transmitting terminal may select or reselect a radio resource commonly included in resource information according to a sensing result and preferred resource set information as a sidelink resource. For example, the transmitting terminal may preferentially select or reselect a resource commonly included in the resource information according to the sensing result performed before or after the reception of the coordination information and the preferred resource set information included in the coordination information.

Alternatively, when the preferred resource set information is included in the coordination information, the transmitting terminal may select or reselect a sidelink resource from among radio resources included in the preferred resource set information without considering a sensing result. That is, the transmitting terminal may select or reselect a sidelink resource only from radio resources included in the preferred resource set information, without using the sensing result sensed by itself.

Alternatively, when the non-preferred resource set information is included in the coordination information, the transmitting terminal may select or reselect a sidelink resource from among the resource information according to the sensing result except for the radio resource included in the non-preferred resource set information. When the resource information according to the sensing result sensed in the sensing window and the radio resource included in the non-preferred resource set information overlap, the transmitting terminal selects or reselects a radio resource from the resource information according to the remaining sensing result except for the overlapped resource. can

When the resource collision information is included in the coordination information, the transmitting terminal may perform a radio resource reselection operation based on the received resource collision information.

According to this, in NR sidelink communication, when the mode 2-based sidelink resource allocation method is applied, a method and apparatus for transmitting and receiving coordination information for sidelink communication capable of avoiding sidelink transmission resource collision between terminals can be provided. have.

15 is a diagram illustrating a procedure for a transmitting terminal to receive coordination information according to an embodiment. The above description in FIG. 14 may be omitted to avoid overlapping description, and in this case, the omitted content may be substantially identically applied to the transmitting terminal as long as it does not go against the spirit of the present invention.

Referring to FIG. 15 , a transmitting terminal may enable transmission/reception of coordination information between terminals ( S1500 ).

When an inter-terminal coordination procedure is required, the transmitting terminal may enable transmission/reception of coordination information between terminals. In this case, according to an example, it is assumed that the receiving terminal and the transmitting terminal support the use of coordination information between the terminals.

However, according to another example, it may be required to confirm whether the receiving terminal and the transmitting terminal each support the use of coordination information between terminals. In this case, the method according to the present disclosure may further include, by the transmitting terminal, transmitting capability information for the coordination information to the receiving terminal, and receiving the capability information for the coordination information from the receiving terminal. .

That is, whether coordination information is supported for each terminal may be transmitted between the base station and the terminal through capability signaling. Specifically, the capability information may be information related to whether transmission/reception is supported for the coordination information or the type or format of the supported coordination information.

When the receiving terminal and the transmitting terminal are terminals supporting transmission/reception of coordination information, transmission/reception of coordination information for sidelink communication may be enabled or disabled. According to an example, the transmitting terminal may determine whether to enable transmission/reception of coordination information based on a cast type of sidelink transmission.

Alternatively, according to another example, the transmitting terminal may determine whether to enable transmission/reception of coordination information based on explicit signaling. For example, whether to enable the corresponding enable may be set through higher layer signaling such as RRC signaling. Alternatively, whether to enable the corresponding enable may be indicated through the sidelink control information. Alternatively, whether to enable transmission and reception of coordination information may be implicitly set according to a preset condition, such as whether a specific SCI format is used.

Referring back to FIG. 15 , the transmitting terminal receives coordination information including a preferred resource or a non-preferred resource set for the transmitting terminal, or including resource conflict information, the receiving terminal. can be received from (S1510).

The receiving terminal may configure coordination information based on the reserved resource information received from the transmitting terminal. According to an example, the receiving terminal may configure the coordination information when the request information for requesting the coordination information is received from the transmitting terminal. The request information from the transmitting terminal may be received by being included in the sidelink control information. In this case, the receiving terminal may configure coordination information including a preferred resource or a non-preferred resource set.

According to an example, the coordination information including the preferred resource or the non-preferred resource set may be configured based on the RSRP value for another transmitting terminal confirmed by the receiving terminal. The receiving terminal may select preferred resource set information based on sidelink reservation resource information of another transmitting terminal. Specifically, the selected at least one radio resource included in the preferred resource set information is sidelink reservation resource information having an RSRP measurement value greater than a preset threshold among sidelink reservation resource information reserved by at least one other transmitting terminal. may be configured to be excluded.

To this end, the receiving terminal may measure RSRP for at least one radio resource included in the sidelink reservation resource information received from at least one other transmitting terminal, respectively. The receiving terminal compares the RSRP value measured for each of at least one radio resource with a preset RSRP threshold. Thereafter, the receiving terminal configures the coordination information so that the reserved resources exceeding the threshold among the reserved resources of other transmitting terminals are not included in the preferred resource set information. This is because, when measured with an RSRP measurement value below a certain level, even if the radio resource overlaps with another transmitting terminal, the possibility of collision with the use of the transmitting terminal due to distance, blockage, etc. is low.

Alternatively, the receiving terminal may select the non-preferred resource set information based on sidelink reservation resource information of another transmitting terminal. Specifically, the non-preferred resource set information includes at least one radio resource determined based on the sidelink reservation resource information reserved by at least one other transmitting terminal that the receiving terminal receives and the RSRP measurement value measured by the receiving terminal. have. For example, the non-preferred resource set information may be determined based on an RSRP measurement value for at least one radio resource included in sidelink reservation resource information reserved by another transmitting terminal.

Similar to the preferred resource set information, for a reserved resource having an RSRP measurement value of a certain level or higher, the receiving terminal may configure it as coordination information. Alternatively, the receiving terminal may include, in the non-preferred resource set information, both a reserved resource reserved by another transmitting terminal and a radio resource having an RSRP measurement value of a predetermined level or higher measured by the receiving terminal.

According to another example, the coordination information including the resource collision information is configured based on whether there is overlap in the time domain or the frequency domain between the resource allocation to the other transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. can be When the radio resource indicated by the sidelink reservation resource information transmitted by the transmitting terminal overlaps with the sidelink reservation resource information reserved by at least one other transmitting terminal that the receiving terminal receives, at least part or all of the resource Coordination information including collision information may be configured.

The receiving terminal may determine whether the reserved resources of the transmitting terminal and the other transmitting terminal overlap by using the sidelink reservation resource information transmitted by the transmitting terminal and the sidelink reservation resource information transmitted by another terminal. When some or all overlap, the receiving terminal may configure coordination information including resource collision information indicating whether collision of sidelink reservation resource information transmitted by the transmitting terminal occurs.

Alternatively, the receiving terminal may configure the coordination information according to the comparison result between the sidelink reservation resource information transmitted by the transmitting terminal and the sidelink radio resource already used by another transmitting terminal for communication. That is, when the reserved resource of the transmitting terminal and the radio resource used by another transmitting terminal overlap at least a part or the whole, the receiving terminal may configure the coordination information.

According to an example, the transmitting terminal receives the configured coordination information using at least one channel of a sidelink control channel (PSCCH), a sidelink data channel (PSSCH), or a sidelink feedback channel (PSFCH) according to the type of coordination information. can do. For example, the first type coordination information about the preferred resource or the non-preferred resource resource set may be received through at least one channel of the PSCCH and the PSSCH. In contrast, the second type coordination information regarding resource collision information may be received through the PSFCH.

The receiving terminal may transmit the coordination information according to a transmission trigger condition of the coordination information. The transmission trigger condition may be set when explicit reporting request information is received from the transmitting terminal or a preset transmission period arrives. In this case, the coordination information may be configured to include preferred resource set information or non-preferred resource set information.

Alternatively, the transmission trigger condition may be set to a case in which an overlap in the time domain or frequency domain is detected between the resource allocation to another transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. In this case, the coordination information may be configured to include resource collision information.

The transmitting terminal may select or reselect a radio resource for sidelink communication based on the received coordination information.

According to an example, the transmitting terminal may select or reselect a sidelink resource based on the coordination information and the sensing result. The transmitting terminal may select or reselect a radio resource by using at least one of preferred resource set or non-preferred resource set information included in the received coordination information and resource information selected as a result of sensing.

When preferred resource set information is included in the coordination information, the transmitting terminal may select or reselect a radio resource commonly included in resource information according to a sensing result and preferred resource set information as a sidelink resource. Alternatively, when the preferred resource set information is included in the coordination information, the transmitting terminal may select or reselect a sidelink resource from among radio resources included in the preferred resource set information without considering a sensing result.

Alternatively, when the non-preferred resource set information is included in the coordination information, the transmitting terminal may select or reselect a sidelink resource from among the resource information according to the sensing result except for the radio resource included in the non-preferred resource set information. When the resource information according to the sensing result sensed in the sensing window and the radio resource included in the non-preferred resource set information overlap, the transmitting terminal selects or reselects a radio resource from the resource information according to the remaining sensing result except for the overlapped resource. can

When the resource collision information is included in the coordination information, the transmitting terminal may perform a radio resource reselection operation based on the received resource collision information.

According to this, in NR sidelink communication, when the mode 2-based sidelink resource allocation method is applied, a method and apparatus for transmitting and receiving coordination information for sidelink communication capable of avoiding sidelink transmission resource collision between terminals can be provided. have.

Hereinafter, each embodiment related to transmission and reception of coordination information for sidelink communication in NR will be described in detail with reference to the related drawings.

In the mode 2 based sidelink radio resource allocation method, an arbitrary sidelink transmitting terminal (sidelink Tx UE) selects a radio resource for sidelink transmission by itself based on a channel sensing result. of radio resource allocation method. That is, any Tx UE may transmit any time resource (eg, sidelink slot) for transmitting the PSCCH and PSSCH to any receiving terminal(s) (Rx UE(s)). and a frequency resource (eg, sub-channel(s)) is defined to be selected based on a result of channel sensing in the corresponding Tx terminal.

However, in the case of a sidelink radio resource selected based only on the sensing result of the Tx UE, it may be a radio resource with severe interference from the side of the Rx UE receiving the sidelink transmission from the corresponding Tx UE. That is, according to the hidden node problem, the Tx UE may perform sidelink transmission through a radio resource with heavy interference from the Rx UE side, which is reliability and delay for sidelink transmission and reception. In terms of performance, it may cause degradation.

Therefore, in the present disclosure, as a method for solving this problem, when the mode 2-based sidelink radio resource allocation method is applied, assistance information for selecting the sidelink radio resource between terminals is configured and the method is transmitted. suggest

As assistance information transmitted from an arbitrary sidelink receiving terminal (sidelink Rx UE) to a sidelink transmitting terminal (sidelink Tx UE), there may be “a set of resources” information. The corresponding a set of resources may be preferred resource information configured based on a sensing result in the Rx UE, and the like. Alternatively, the corresponding a set of resources may be non-preferred radio resource information configured based on a sensing result in the Rx UE. Alternatively, as the assistance information, it may be indication information on a sidelink resource conflict. The resource conflict information may be pre-conflict indication information for a reserved resource, or post-conflict indication information for sidelink transmission that has already occurred.

When various types/types of assistance information are defined as described above, it is necessary to define which types/types of assistance information to be transmitted from the Rx UE to the Tx UE or to a third UE or base station. That is, when one or more formats/types or types of assistance information are defined, a method for determining the format/type or types of assistance information to be transmitted from an arbitrary UE is proposed.

Example 1: Capability and enabling/disabling of assistance information

Whether or not the above-described assistance information is supported for each terminal may be defined to be transmitted between the base station and the terminal through capability signaling. Specifically, the corresponding capability information may be information on whether transmission of assistance information is supported, whether reception of assistance information is supported, or type/format related information of assistance information.

Whether assistance information transmission/reception is supported according to PSSCH transmission/reception between terminals supporting arbitrary assistance information transmission/reception or for PSSCH transmission/reception may be enabled or disabled. As an example for determining whether the corresponding assistance information is supported or enabling/disabling, whether the corresponding assistance information is supported or enabling/disabling may be determined by a cast type of PSSCH transmission. For example, in the case of broadcast, assistance information is not supported, that is, transmission of assistance information is defined to be disabling, and in case of gruopcast or unicast, assistance information may be defined to be enabled. As another example, it may be defined such that transmission/reception of assistance information is disabled for broadcast/groupcast and assistance information is enabled only for unicast.

As another example, whether assistance information is supported or whether enabling/disabling may be determined by explicit signaling. For example, whether or not to support transmission/reception of assistance information or enabling/disabling is set through RRC signaling, or enabling/disabling information of the corresponding assistance information is indicated through a sidelink control information format (SCI format). can Alternatively, whether assistance information is supported or whether enabling/disabling may be implicitly indicated. For example, a specific 1st ^-stage SCI format may be used for assistance information enabling, or a specific ^2nd -stage SCI format may be used for assistance information enabling.

As another example, whether assistance information is supported or enabling/disabling may be configured for each sidelink cluster/coverage constituting mode 2-based sidelink transmission/reception. For example, whether or not support or enabling/disabling information is included for the transmission and reception of the assistance information through the Physical Sidelink Broadcast CHannel (PSBCH) transmitted from the sink and source node constituting an arbitrary sidelink cluster/coverage. can be defined to be transmitted. Alternatively, when the sidelink synchronization signal (S-SS) is transmitted, it may be defined to implicitly include information on whether to support corresponding assistance information and enabling/disabling information.

As another example, based on location information between terminals, that is, zone ID information based on a geodesic distance, whether to support or enable/disabling corresponding assistance information may be set. have. Alternatively, whether to support assistance information or whether to enable/disabling may be configured according to the inter-terminal sidelink CSI information. As such, when enabling/disabling is determined according to location information or inter-terminal sidelink CSI information, an arbitrary threshold value serving as a reference value of the corresponding enabling/disabling is RRC signaling or L1 control signaling from the base station/network or the terminal. (eg, PDCCH or PSCCH, etc.) may be configured/indicated.

Additionally, whether assistance information is supported or enabling/disabling may be made through a combination of two or more examples with respect to the above-described examples. For example, whether assistance information is supported is determined according to the cast type, and enabling of assistance information through the above-described explicit signaling (eg, RRC signaling or SCI format transmission) for a cast type in which assistance information is additionally supported /disabling can be determined.

Example 2: Determination of type/format of assistance information

When assistance information is transmitted/received between arbitrary terminals according to the method of Embodiment 1 or another method described above, it is necessary to determine the type/format of the corresponding assistance information. Hereinafter, a method for determining the corresponding assistance information type/format for transmission and reception of arbitrary assistance information is proposed.

Determination by Cast Type

It may be defined so that the type/format(s) of assistance information is determined for each cast type. That is, the type/format of assistance information of the corresponding Rx UE may be determined according to the cast type of the PSSCH received by any Rx UE. That is, as an example, in the case of broadcast, assistance information is configured and transmitted as indication information for resource conflict, and in the case of groupcast, a set of non-preferred resources is configured and transmitted in configuring a set of resources, In the case of unicast, it can be defined to configure and transmit a preferred resource set. However, this is not limited thereto, and all cases in which the assistance information type/format is determined by the cast type may be included in the scope of the present invention.

Decision by explicit or implicit signaling

An assistance information type/format may be set or indicated in any terminal or base station.

For example, a source node constituting an arbitrary sidelink cluster may transmit type/format configuration information of assistance information to be transmitted/received by sidelink terminals in the corresponding cluster through S-SS or PSBCH. Alternatively, the base station constituting a cell sets the assistance information format/type for mode-2 based terminals of the sidelink terminals in the cell to perform cell-specific/UE-specific RRC signaling or It can be transmitted through L1 control signaling. Alternatively, any Tx UE may transmit assistance information type/format configuration information through PC5 RRC signaling. Alternatively, assistance information type/format indication information may be included in the SCI format and it may be defined to be transmitted through the PSCCH.

Alternatively, assistance information type/format information may be implicitly indicated. For example, a specific 1 ^st -stage SCI format may be used or a specific 2 ^nd -stage SCI format may be used to indicate the assistance information type/format.

Define triggering conditions for each assistance information type/format

A separate triggering condition may be defined for each assistance information type/format described above, and when the corresponding triggering condition is satisfied, the corresponding assistance information type/format may be transmitted. The triggering condition includes sidelink CSI information, location information (eg, zone ID), a sidelink resource for PSSCH transmission in the Tx UE, or resource conflict on a sidelink resource reserved for PSSCH transmission, or a corresponding sidelink resource. An interference level with respect to may be used.

For example, in the Rx UE, according to the PSCCH reception information, PSSCH transmission resources of different Tx UEs fully or partially overlap in time or frequency domain, resource conflict. When detected (detection), the assistance information may be indication information for the corresponding resource conflict. Alternatively, when the interference level in a radio resource or a reserved radio resource in which PSSCH transmission is performed in the Tx UE is higher than a specific threshold value, the corresponding assistance information may be preferred resource set configuration information or non-preferred resource set configuration information.

Additionally, all cases in which the assistance information type/format is determined in the form of all combinations of the above-described methods may be included in the scope of the present invention.

In addition, the present disclosure proposes a reporting procedure for each assistance information type/format described above.

Example 3. Reporting procedure for each assistance information type/format

In defining the reporting procedure for assistance information, the reporting procedure can be defined separately by first classifying assistance information including preferred or non-preferred radio resource set information among the aforementioned assistance information and assistance information for indicating resource conflict. have.

That is, when an arbitrary terminal configures and transmits or receives assistance information, assistance information composed of an arbitrary preferred or non-preferred sidelink resource set may be defined as type-1 assistance information. On the other hand, resource conflict indication information or interference avoidance for a sidelink radio resource allocated for PSSCH transmission in an arbitrary Tx terminal, that is, a radio resource allocated or reserved for PSSCH transmission by arbitrary SCI format transmission. For such purposes, assistance information including high-interference indication information may be defined as separate type-2 assistance information.

That is, the sidelink assistance information is type-1 assistance information consisting of recommended resource set information for sidelink transmission and a type consisting of resource conflict indication or resource reselection indication/request information accordingly. -2 can be classified as assistance information.

As such, when the assistance information is defined as a multi-type, a separate reporting procedure may be defined for each assistance information type.

As an example, restrictions may be placed on the type of assistance information supported according to the sidelink cast type. For example, type-1 assistance information may be defined to be applied to all cast types, and type-2 assistance information may be defined to be applied only to groupcast and unicast.

That is, as shown in Table 2 below, a table defining a cast type supported by each assistance information type may be defined. However, the content of Table 2 below is an example of a mapping table for a cast type supported by each assistance information type, and is not limited thereto. All other information constituting the cast type mapping table for each assistance information type Combinations may be included within the scope of the present invention.

Assistance information type Supported cast type Type-1 assistance information Broadcast, groupcast, unicast Type-2 assistance information unicast

As another example, a reporting channel for assistance information may be defined for each type of assistance information. For example, the aforementioned type-1 assistance information may be defined to be transmitted through a PSCCH or a PSSCH. On the other hand, in the case of the aforementioned type-2 assistance information, it may be defined to be transmitted through the PSFCH. This is an example, not limited thereto, and vice versa may also be applied.

As another example, a separate triggering procedure may be defined for each type of assistance information described above. For example, type-1 assistance information may be triggered through higher layer signaling or may be triggered or enabled through SCI format.

Embodiment 4. Reporting for Assistance information, triggering procedure

Reporting and triggering procedures for assistance information may also be separately applied according to assistance information. As an example of this, the aforementioned type-1 assistance information may be defined to be set through higher layer signaling and reported periodically, or additionally reported when information modification is required after initial reporting. That is, when type-1 assistance information reporting is set for an arbitrary terminal, the corresponding terminal configures preferred resource set or non-preferred resource set information and transmits it through PSCCH or PSSCH with an arbitrary period, and the period information is also higher It can be set through layer signaling.

Alternatively, when type-1 assistance information reporting is configured for an arbitrary terminal, the corresponding terminal configures preferred resource set or non-preferred resource set information to perform initial assistance information reporting. Thereafter, it may be defined to modify and report the preferred resource set or non-preferred resource set configuration information based on the change information only when a change to the preferred resource set or non-preferred resource set configuration information for initial reporting occurs.

Alternatively, reporting of the corresponding type-1 assistance information may be requested by SCI transmitted by any Tx UE. That is, any SCI format may be defined to include indication information for requesting corresponding assistance information, that is, assistance information request indication information. In this case, it may be defined to configure and report type-1 assistance information in any Rx UE based on the corresponding indication information. In this case, whether the corresponding assistance information request indication information is included may be set by RRC signaling, and a separate SCI format including the information may be defined.

On the other hand, type-2 assistance information may indicate triggering/request information for each SCI to which PSSCH transmission is allocated. That is, in the case of the corresponding type-2 assistance information, reporting may be made through the PSFCH or the PSCCH as conflict indication information for any transmitted PSSCH or reserved PSSCH. Accordingly, during SCI transmission to which the corresponding PSSCH transmission assignment is made, the Tx UE may transmit request indication information for the corresponding assistance information. In this case, whether the corresponding assistance information request indication information is included may be set by RRC signaling, and a separate SCI format including the information may be defined. In addition, in the case of the corresponding type-2 assistance information, it may be defined to be supported only when the HARQ operation is enabled. That is, when HARQ reporting is disabling for any Rx UE, the Rx UE may be defined not to expect a request/trigger for type-2 assistance information reporting.

Additionally, in applying the reporting procedure for each assistance information type presented in the present invention, all combinations of the aforementioned reporting procedure and assistance information type may be included in the scope of the present invention.

In addition, the present disclosure proposes a specific method of configuring the inter-UE coordination information of scheme 1.

As described above, the inter-UE coordination information of scheme 1 is transmitted to the transmitting terminal by configuring a preferred resource set or a non-preferred resource set. Therefore, a specific definition of a resource pool defining a preferred resource set or a non-preferred resource set is required.

According to an example, for this, a reference sidelink resource set serving as a reference for defining a preferred resource set or a non-preferred resource set may be configured. For example, a reference sidelink resource set including N sidelink slots and M subchannels may be configured. Based on this reference sidelink resource set, the receiving terminal may configure and transmit a preferred resource set or a non-preferred resource set in a 2D bitmap method.

According to this, in NR sidelink communication, when the mode 2-based sidelink resource allocation method is applied, a method and apparatus for transmitting and receiving coordination information for sidelink communication capable of avoiding sidelink transmission resource collision between terminals can be provided. have.

Hereinafter, configurations of a receiving terminal and a transmitting terminal capable of performing some or all of the embodiments described with reference to FIGS. 1 to 16 will be described with reference to the drawings. The above description may be omitted to avoid duplicate description, and in this case, the omitted content may be substantially identically applied to the following description unless it goes against the technical spirit of the present invention.

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

Referring to FIG. 17 , the reception 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 reception terminal 1700 according to the method for transmitting and receiving coordination information for sidelink communication necessary for carrying out the above-described present invention. The transmitter 1720 transmits uplink control information, data, and message to the base station through the corresponding channel, and transmits the sidelink control information, data, and message to the transmitting terminal or sidelink scheduling terminal through the corresponding channel. The receiver 1730 receives downlink control information, data, and messages from the 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 controller 1710 may enable transmission/reception of coordination information between terminals. When an inter-terminal coordination procedure is required, the controller 1710 may enable transmission/reception of coordination information between terminals. In this case, according to an example, it is assumed that the receiving terminal and the transmitting terminal support the use of coordination information between the terminals.

However, according to another example, it may be required to confirm whether the receiving terminal and the transmitting terminal each support the use of coordination information between terminals. In this case, the transmitter 1720 may transmit capability information for the coordination information to the transmitting terminal. The receiving unit 1730 may receive capability information for coordination information from the transmitting terminal.

According to an example, the controller 1710 may determine whether to enable transmission/reception of coordination information based on explicit signaling. For example, whether to enable the corresponding enable may be set through higher layer signaling such as RRC signaling. Alternatively, whether to enable the corresponding enable may be indicated through the sidelink control information. Alternatively, whether to enable transmission and reception of coordination information may be implicitly set according to a preset condition, such as whether a specific SCI format is used.

The control unit 1710 may configure coordination information including a preferred resource or a non-preferred resource set for the transmitting terminal, or including resource conflict information.

The control unit 1710 may configure coordination information based on the reserved resource information received from the transmitting terminal. According to an example, when the request information for requesting coordination information is received from the transmitting terminal, the control unit 1710 may configure the coordination information. The request information from the transmitting terminal may be received by being included in the sidelink control information. In this case, the controller 1710 may configure coordination information including a preferred resource or a non-preferred resource set.

According to an example, the coordination information including the preferred resource or the non-preferred resource set may be configured based on the RSRP value for the other transmitting terminal confirmed by the controller 1710 . The control unit 1710 may select preferred resource set information based on sidelink reservation resource information of another transmitting terminal. Specifically, the selected at least one radio resource included in the preferred resource set information is sidelink reservation resource information having an RSRP measurement value greater than a preset threshold among sidelink reservation resource information reserved by at least one other transmitting terminal. may be configured to be excluded.

Alternatively, the controller 1710 may select the non-preferred resource set information based on sidelink reservation resource information of another transmitting terminal. Specifically, the non-preferred resource set information includes at least one radio resource determined based on the sidelink reservation resource information reserved by at least one other transmitting terminal that the receiving terminal receives and the RSRP measurement value measured by the receiving terminal. have.

Similar to the preferred resource set information, for a reserved resource having a RSRP measurement value of a certain level or higher, the controller 1710 may configure it as coordination information. Alternatively, the control unit 1710 may include both a reserved resource reserved by another transmitting terminal and a radio resource having an RSRP measurement value of a predetermined level or higher measured by the receiving terminal in the non-preferred resource set information.

According to another example, the coordination information including the resource collision information is configured based on whether there is overlap in the time domain or the frequency domain between the resource allocation to the other transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. can be When the radio resource indicated by the sidelink reservation resource information transmitted by the transmitting terminal overlaps with the sidelink reservation resource information reserved by at least one other transmitting terminal received by the receiving terminal at least partially or entirely, the control unit 1710 , it is possible to configure coordination information including resource collision information.

The control unit 1710 may determine whether the reserved resources of the transmitting terminal and the other transmitting terminal overlap by using the sidelink reservation resource information transmitted by the transmitting terminal and the sidelink reservation resource information transmitted by another terminal. When some or all of them overlap, the control unit 1710 may configure coordination information including resource collision information indicating whether collision of sidelink reservation resource information transmitted from the transmitting terminal occurs.

The transmitter 1720 may transmit coordination information. According to an example, the transmitter 1720 uses at least one channel of a sidelink control channel (PSCCH), a sidelink data channel (PSSCH), or a sidelink feedback channel (PSFCH) for the configured coordination information according to the type of coordination information. can be transmitted. For example, the first type coordination information regarding the preferred resource or the non-preferred resource resource set may be transmitted through at least one channel of the PSCCH and the PSSCH. In contrast, the second type coordination information regarding resource collision information may be transmitted through the PSFCH.

The transmitter 1720 may transmit the coordination information according to a transmission trigger condition of the coordination information. The transmission trigger condition may be set when explicit reporting request information is received from the transmitting terminal or a preset transmission period arrives. In this case, the coordination information may be configured to include preferred resource set information or non-preferred resource set information.

Alternatively, the transmission trigger condition may be set to a case in which an overlap in the time domain or frequency domain is detected between the resource allocation to another transmitting terminal and the resource allocation to the transmitting terminal confirmed by the control unit 1710 . In this case, the coordination information may be configured to include resource collision information.

According to this, in NR sidelink communication, when the mode 2-based sidelink resource allocation method is applied, a method and apparatus for transmitting and receiving coordination information for sidelink communication capable of avoiding sidelink transmission resource collision between terminals can be provided. have.

18 is a diagram showing the configuration of a transmitting terminal 1800 according to another embodiment.

Referring to FIG. 18 , a transmitting terminal 1800 according to another embodiment includes a control unit 1810 , a transmitting unit 1820 , and a receiving unit 1830 .

The control unit 1810 controls the overall operation of the transmitting terminal 1800 according to a method of transmitting and receiving coordination information for sidelink communication necessary for carrying out the above-described present invention. The transmitter 1720 transmits the uplink control information, data, and message to the base station through the corresponding channel, and transmits the sidelink control information, data, and message to the receiving terminal through the corresponding channel. The receiving unit 1730 receives downlink control information, data, and messages from the base station through the corresponding channel, and receives sidelink control information, data, and messages from the receiving terminal through the corresponding channel.

The controller 1810 may enable transmission/reception of coordination information between terminals. When an inter-terminal coordination procedure is required, the controller 1810 may enable transmission/reception of coordination information between terminals. In this case, according to an example, it is assumed that the receiving terminal and the transmitting terminal support the use of coordination information between the terminals.

However, according to another example, it may be required to confirm whether the receiving terminal and the transmitting terminal each support the use of coordination information between terminals. In this case, the transmitter 1820 may transmit capability information for the coordination information to the receiving terminal. The receiving unit 1830 may receive capability information for coordination information from the receiving terminal.

According to an example, the controller 1810 may determine whether to enable transmission/reception of coordination information based on explicit signaling. For example, whether to enable the corresponding enable may be set through higher layer signaling such as RRC signaling. Alternatively, whether to enable the corresponding enable may be indicated through the sidelink control information. Alternatively, whether to enable transmission and reception of coordination information may be implicitly set according to a preset condition, such as whether a specific SCI format is used.

The receiving unit 1830 may receive coordination information including a preferred resource or a non-preferred resource set for the transmitting terminal or including resource conflict information from the receiving terminal. .

The receiving terminal may configure coordination information based on the reserved resource information received from the transmitting terminal. According to an example, the receiving terminal may configure the coordination information when the request information for requesting the coordination information is received from the transmitting terminal. The request information from the transmitting terminal may be received by being included in the sidelink control information. In this case, the receiving terminal may configure coordination information including a preferred resource or a non-preferred resource set.

According to an example, the coordination information including the preferred resource or the non-preferred resource set may be configured based on the RSRP value for another transmitting terminal confirmed by the receiving terminal. The receiving terminal may select preferred resource set information based on sidelink reservation resource information of another transmitting terminal. Specifically, the selected at least one radio resource included in the preferred resource set information is sidelink reservation resource information having an RSRP measurement value greater than a preset threshold among sidelink reservation resource information reserved by at least one other transmitting terminal. may be configured to be excluded.

Alternatively, the receiving terminal may select the non-preferred resource set information based on sidelink reservation resource information of another transmitting terminal. Specifically, the non-preferred resource set information includes at least one radio resource determined based on the sidelink reservation resource information reserved by at least one other transmitting terminal that the receiving terminal receives and the RSRP measurement value measured by the receiving terminal. have.

According to another example, the coordination information including the resource collision information is configured based on whether there is overlap in the time domain or the frequency domain between the resource allocation to the other transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. can be When the radio resource indicated by the sidelink reservation resource information transmitted by the transmitting terminal overlaps with the sidelink reservation resource information reserved by at least one other transmitting terminal that the receiving terminal receives, at least part or all of the resource Coordination information including collision information may be configured.

According to an example, the receiving unit 1830 uses at least one of a sidelink control channel (PSCCH), a sidelink data channel (PSSCH), and a sidelink feedback channel (PSFCH) for the configured coordination information according to the type of coordination information. can be received. For example, the first type coordination information about the preferred resource or the non-preferred resource resource set may be received through at least one channel of the PSCCH and the PSSCH. In contrast, the second type coordination information regarding resource collision information may be received through the PSFCH.

The receiving terminal may transmit the coordination information according to a transmission trigger condition of the coordination information. The transmission trigger condition may be set when explicit reporting request information is received from the transmitting terminal or a preset transmission period arrives. In this case, the coordination information may be configured to include preferred resource set information or non-preferred resource set information.

Alternatively, the transmission trigger condition may be set to a case in which an overlap in the time domain or frequency domain is detected between the resource allocation to another transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. In this case, the coordination information may be configured to include resource collision information.

The controller 1810 may select or reselect a radio resource for sidelink communication based on the received coordination information.

According to an example, the controller 1810 may select or reselect a sidelink resource based on the coordination information and the sensing result. The controller 1810 may select or reselect a radio resource by using at least one of preferred resource set or non-preferred resource set information included in the received coordination information and resource information selected as a result of sensing.

When the coordination information includes preferred resource set information, the controller 1810 may select or reselect, as a sidelink resource, a radio resource commonly included in the resource information according to the sensing result and the preferred resource set information. Alternatively, when preferred resource set information is included in the coordination information, the controller 1810 may select or reselect a sidelink resource from among radio resources included in the preferred resource set information without considering a sensing result.

Alternatively, when non-preferred resource set information is included in the coordination information, the controller 1810 may select or reselect a sidelink resource from resource information according to the sensing result except for a radio resource included in the non-preferred resource set information. When the resource information according to the sensing result sensed in the sensing window overlaps the radio resource included in the non-preferred resource set information, the control unit 1810 selects a radio resource from the resource information according to the remaining sensing result except for the overlapped resource can be re-selected.

When the coordination information includes resource collision information, the controller 1810 may perform a radio resource reselection operation based on the received resource collision information.

According to this, in NR sidelink communication, when the mode 2-based sidelink resource allocation method is applied, a method and apparatus for transmitting and receiving coordination information for sidelink communication capable of avoiding sidelink transmission resource collision between terminals can be provided. have.

The above-described embodiments may 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 not described in order to clearly reveal the present technical idea among the present embodiments may be supported by the above-described standard documents. In addition, all terms disclosed in this specification can be explained by the standard documents disclosed above.

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

In the case of implementation by hardware, the method according to the present embodiments may include one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), may be implemented by a processor, a controller, a microcontroller or a microprocessor.

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

Also, as described above, terms such as "system", "processor", "controller", "component", "module", "interface", "model", or "unit" generally refer to computer-related entities hardware, hardware and software. may mean a combination of, software, or running software. For example, the aforementioned component may be, but is not limited to, a process run by a processor, a processor, a controller, a controlling processor, an object, a thread of execution, a program, and/or a computer. For example, both an application running on a controller or processor and a controller or processor can be a component. One or more components may reside within a process and/or thread of execution, and the components may 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 spirit of the present disclosure, and various modifications and variations will be possible without departing from the essential characteristics of the present disclosure by those skilled in the art to which the present disclosure pertains. In addition, the present embodiments are not intended to limit the technical spirit of the present disclosure, but to explain, and thus the scope of the present technical spirit is not limited by these embodiments. The protection scope of the present disclosure should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present disclosure.

Claims (20)

In a method for a receiving terminal to transmit coordination information,
enabling transmission and reception of coordination information between terminals;
configuring coordination information including a preferred resource or a non-preferred resource set for the transmitting terminal or including resource conflict information; and
and transmitting the coordination information. The method of claim 1,
The method further comprising the step of transmitting the capability (capability) information for the coordination information to the transmitting terminal, and receiving the capability information for the coordination information from the transmitting terminal. The method of claim 1,
Enabling transmission and reception of the coordination information,
A method that is explicitly set through higher layer signaling or sidelink control information, or is set implicitly according to a preset condition. The method of claim 1,
Coordination information including the preferred resource or non-preferred resource set,
A method configured based on the RSRP value for another transmitting terminal identified in the receiving terminal. The method of claim 1,
Coordination information including the resource collision information,
A method configured based on whether there is an overlap in the time domain or the frequency domain between the resource allocation to the other transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. In a method for a transmitting terminal to receive coordination information,
enabling transmission and reception of coordination information between terminals; and
A method comprising: receiving, from a receiving terminal, coordination information including a preferred resource or a non-preferred resource set for the transmitting terminal, or including resource conflict information. 7. The method of claim 6,
The method further comprising the step of transmitting the capability (capability) information for the coordination information to the receiving terminal, and receiving the capability information for the coordination information from the receiving terminal. 7. The method of claim 6,
Enabling transmission and reception of the coordination information,
A method that is explicitly set through higher layer signaling or sidelink control information, or is set implicitly according to a preset condition. 7. The method of claim 6,
Coordination information including the preferred resource or non-preferred resource set,
A method configured based on the RSRP value for another transmitting terminal identified in the receiving terminal. 7. The method of claim 6,
Coordination information including the resource collision information,
A method configured based on whether there is an overlap in the time domain or the frequency domain between the resource allocation to the other transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. In the receiving terminal for transmitting coordination information,
Enables transmission and reception of coordination information between terminals, and includes a preferred resource or a non-preferred resource set for the transmitting terminal, or a coordination including resource conflict information a control unit that configures information; and
A terminal including a transmitter for transmitting the coordination information. 12. The method of claim 11,
The transmitter is
Transmitting capability information for the coordination information to the transmitting terminal,
The terminal further comprising a receiver for receiving the capability information for the coordination information from the transmitting terminal. 12. The method of claim 11,
Enabling transmission and reception of the coordination information,
A terminal that is explicitly set through higher layer signaling or sidelink control information, or is set implicitly according to a preset condition. 12. The method of claim 11,
Coordination information including the preferred resource or non-preferred resource set,
A terminal configured based on the RSRP value for another transmitting terminal identified in the receiving terminal. 12. The method of claim 11,
Coordination information including the resource collision information,
A terminal configured on the basis of whether there is an overlap in the time domain or the frequency domain between the resource allocation to the other transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal. In the transmitting terminal for receiving the coordination information (coordination information),
a control unit for enabling transmission and reception of coordination information between terminals; and
A terminal including a receiver for receiving coordination information including a preferred resource or a non-preferred resource set for the transmitter terminal or including resource conflict information from the receiver terminal. 17. The method of claim 16,
Further comprising a transmitter for transmitting capability (capability) information for the coordination information to the receiving terminal,
The receiving unit,
A terminal for receiving capability information for the coordination information from the receiving terminal. 17. The method of claim 16,
Enabling transmission and reception of the coordination information,
A terminal that is explicitly set through higher layer signaling or sidelink control information, or is set implicitly according to a preset condition. 17. The method of claim 16,
Coordination information including the preferred resource or non-preferred resource set,
A terminal configured based on the RSRP value for another transmitting terminal identified in the receiving terminal. 17. The method of claim 16,
Coordination information including the resource collision information,
A terminal configured on the basis of whether there is an overlap in the time domain or the frequency domain between the resource allocation to the other transmitting terminal and the resource allocation to the transmitting terminal confirmed by the receiving terminal.

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