KR20210127282A - Method and apparatus for sidelink transmission and reception of terminal in a next generation wireless network - Google Patents

Abstract

The present disclosure provides a method for performing an operation having a higher priority based on a predetermined priority when sidelink transmission or reception and uplink transmission overlap in a time domain in a terminal, in a method for sidelink transmission and reception of a terminal.

Description

A method and apparatus for transmitting and receiving a sidelink of a terminal in a next-generation wireless network

The present disclosure relates to a method and apparatus for transmitting and receiving a sidelink of a 5G radio access-based terminal.

In one aspect, the present embodiments, in the sidelink transmission and reception method of the terminal, when the sidelink transmission or reception and the uplink transmission in the terminal overlap in the time domain, the priority is further based on a predetermined priority It can provide a way to perform a high action.

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 the present embodiment can be applied.
7 is a diagram for explaining CORESET.
8 is a diagram for explaining, for example, a DMRS structure for a conventional sidelink and a DMRS structure for a sidelink to which this embodiment can be applied.
9 is a diagram for explaining various scenarios for V2X communication.
10 is a diagram illustrating an example of terminal 1 (UE1) and terminal 2 (UE2) performing sidelink communication and a sidelink resource pool used by them.
11 is a diagram for explaining a method of bundling and transmitting HARQ feedback information in V2X.
12 is a diagram illustrating an example of multiplexing PSSCH associated with PSCCH associated with V2X.
13 is a diagram for explaining Example of symbol level alignment among different SCS.
14 is a diagram for explaining a conceptual example of a bandwidth part.
15 is a diagram showing the configuration of a base station according to another embodiment.
16 is a diagram showing the configuration of a user 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 thereof 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 the components, when two or more components are described as being "connected", "coupled" or "connected", the two or more components are directly "connected", "coupled" or "connected" ", but it will be understood that 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, the manufacturing method, etc., for example, a temporal precedence relationship such as "after", "after", "after", "before", etc. Or, 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, the numerical value or the corresponding information is based on various factors (eg, process factors, internal or external shock, Noise, etc.) may be interpreted as including an error range that may occur.

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 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 the downlink and SC- in the 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, the terminal in the present specification is a comprehensive concept meaning a device including a wireless communication module for performing communication with a base station in a wireless communication system, WCDMA, LTE, NR, HSPA and IMT-2020 (5G or New Radio), etc. It should be interpreted as a concept including all of UE (User Equipment), MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), wireless device, and the like 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 the 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 in 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), and 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, and the transmission/reception point itself. can

Uplink (Uplink, UL, or uplink) refers to a method of transmitting and receiving data by the terminal to and from the base station, and downlink (Downlink, DL, or downlink) refers to a method of transmitting and receiving data to and from the terminal by the 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. Also, 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 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 and 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'. do.

For clarity of explanation, the present technical idea will be 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 improves LTE-Advanced technology according to 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 focusing 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 connection, and the URLLC (Ultra Reliability and Low Latency) scenario that requires high responsiveness and reliability and supports high-speed mobility. .

To satisfy this scenario, NR discloses a wireless communication system to which a new waveform and frame structure technology, low latency technology, mmWave support technology, and forward compatible technology are applied. In particular, in the NR system, various technical changes are presented in terms of flexibility in order 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. The gNB interconnects or gNBs and ng-eNBs are interconnected via an Xn interface. gNB and ng-eNB are each connected to 5GC through the NG interface. 5GC may be configured to 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 frequency bands below 6 GHz (FR1, Frequency Range 1) and frequency bands 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 refer to gNB or ng-eNB separately 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, the 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 to

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

As shown in Table 1 above, the NR pneumatology can be divided into five types according to the subcarrier spacing. This is different from the fact that the subcarrier interval of LTE, one of the 4G communication technologies, is fixed at 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, 120, 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 the subcarrier interval. For example, in the case of a numerology having a 15 kHz subcarrier interval, the slot is 1 ms long and is composed of 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.

On the other hand, 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) 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 HARQ delay, a slot structure capable of transmitting HARQ ACK/NACK directly within a transmission slot is defined, and this slot structure is named as a self-contained structure and will be described.

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 carrying a symbol on one antenna port can be inferred from a channel carrying a symbol on another antenna port, 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 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 numerology 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 activated bandwidth part 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 UE 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 wideband operation is supported. Accordingly, the UE monitors the SSB using a synchronization raster, which is a candidate frequency location for monitoring the SSB. The carrier raster and synchronization raster, which are the center frequency location information of the channel for initial access, are newly defined in NR, and the synchronization raster has a wider frequency interval than the carrier raster, so that the terminal can support fast SSB search. 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, etc.), offset information between the common resource block and the SSB (the position of the absolute SSB in the carrier is transmitted through SIB1), and the like. Here, the SIB1 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 terminal.

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

Referring to FIG. 6 , 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 a UE initially accesses a cell, a contention-based random access procedure is performed, and when performing random access 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 terminals, the random access preamble identifier may be included to inform which terminal the included UL Grant, temporary C-RNTI, and TAC are valid. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the UE to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, that is, 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 up/down 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 candidates by 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 between terminals (ie, sidelink) was made to provide direct communication between terminals and V2X (particularly V2V) service.

Regarding the sidelink, PSSS/SSSS, which is a synchronization signal for synchronization between a wireless sidelink transmitter and a receiver, and a Physical Sidelink Broadcasting Channel (PSBCH) for transmitting and receiving a sidelink MIB (Master Information Block) related thereto 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 of radio resources. 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 the 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, a technology development for improving the performance of the sidelink technology developed based on the conventional D2D communication according to the requirements of V2X has been progressed. 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. 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.

<Sidelink Physical Layer Design>

For V2X communication, a demodulation reference signal (DMRS), which is a pilot signal, needs to be allocated more than D2D communication in order to improve channel estimation performance and frequency offset estimation performance.

8 is a diagram for explaining, for example, a DMRS structure for a conventional sidelink and a DMRS structure for a sidelink to which this embodiment can be applied.

Referring to FIG. 8 , two conventional (Rel-12/13) DMRSs are allocated per subframe of PSCCH, PSSCH, and PSBCH, and the interval between DMRSs is 0.5 ms. The C-V2X terminal uses the 6GHz center frequency band defined for sidelink transmission, and the vehicle terminal moves at 280km/h considering the relative speed. At this time, the correlation time becomes 0.277 ms, and since this value is shorter than the interval between reference signals of Rel-12/13, the channel estimation time is insufficient. To solve this problem, in the sidelink for V2X communication, the number of DMRSs per subframe was increased to 4 and the interval between reference signals was reduced to 0.214 ms, so that the physical layer design was changed to facilitate channel estimation even with rapid channel changes. .

On the other hand, as one example of a method of selecting a DMRS symbol pattern, in a dedicated carrier, DMRS is allocated to OFDM symbols 2/5/8/11 in PSCCH/PSSCH, and DMRS in OFDM symbols 3/5/8/10 in PSBCH. allocate In the 2GHz band, the Rel-12/13 method with two DMRSs can be used as it is. That is, the number and pattern of DMRS transmission may be configured differently according to channels and carrier frequency bands.

In addition, the TDM (Time Division Multiplexing) method used in D2D uses the FDM (Frequency Division Multiplexing) method because it is not suitable for C-V2X in which a large number of vehicles are densely connected at the same time.

<Resource Allocation>

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

Referring to FIG. 9 , 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 a 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 a base station (UE N-1, UE G-1, UE X), and between terminals within coverage of a 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 order for the corresponding terminal to perform communication using the sidelink in these various scenarios, allocation of radio resources for communication is required, and allocation of radio resources 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 a preset resource (Mode 2) in D2D. 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.

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

Referring to FIG. 10 , the 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. 10A , 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 the UE1 is outside the connection range of the base station, another terminal may inform it 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. 10( 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 transmission of the following sidelink data channel and information such as the modulation and coding scheme (MCS), MIMO transmission method, and timing advance (TA) required for demodulation of other data channels. It may be a signal including This signal may 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 form 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 may 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 a transmitting terminal transmits information such as its ID so that a 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 in the same sidelink data channel or discovery message, the transmission timing determination method of the sidelink signal (for example, whether it is transmitted at the 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 independently select individual signal transmission resources within the pool), signal format (e.g., each sidelink signal is 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. To this end, it is important that the terminal located outside the coverage of the base station acquires synchronization.

Hereinafter, based on the above description, a method for 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. 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 signals may correspond to GNSS signals such as 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 the basic system information that the UE must 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 directly communicate 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 A PUCCH resource and feedback timing may be indicated by a timing indicator (PDSCH-to-HARQ feedback timing indicator).

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

Referring to FIG. 11 , 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 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 SCS (subcarrier spacing). 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 decided to be 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. 12 . 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, helps the sidelink resource selection for other UE(s), is configured with a configured grant for sidelink transmission, or a sidelink of another UE(s) Transmissions can be scheduled.

NR preemtion

In the case of a terminal that is critical to delay, such as a URLLC terminal, even a data resource already allocated to another eMBB terminal or the like may be preempted to use the data resource. In addition, information on which area of the data resource is occupied may be indicated to the terminal through the group common DCI.

Uu interface based sidelink resource allocation/configuration

The NR Uu may allocate NR sidelink resources for a shared licensed carrier and/or a dedicated NR sidelink carrier between the Uu and the NR sidelink. In this case, resource allocation may support dynamic resource allocation and activation/deactivation-based resource allocation. Activation/deactivation-based resource allocation may reuse SPS allocation or NR grant free type-2.

In this 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) 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 was designed to satisfy various QoS requirements required for each segmented and detailed usage scenario as well as an improved data rate compared to LTE. In particular, eMBB (enhancement Mobile BroadBand), mMTC (massive MTC), and URLLC (Ultra Reliable and Low Latency Communications) are defined as representative usage scenarios of NR. Structural design is required. Since each usage scenario has different requirements for data rates, latency, reliability, coverage, etc., different numerology ( eg subcarrier spacing, subframe, TTI, etc.) based radio resource unit (unit) is designed to efficiently multiplex.

As a method for this, a method for supporting multiplexing based on TDM, FDM or TDM/FDM through one or a plurality of NR component carrier(s) for numerology having different subcarrier spacing values and a scheduling unit in the time domain In the configuration, there was a discussion about how to support more than one time unit. In this regard, in NR, a subframe is defined as a type of time domain structure, and as a reference numerology for defining the corresponding subframe duration, 14 OFDM symbols of the same 15 kHz Sub-Carrier Spacing (SCS)-based normal CP overhead as in LTE It was decided to define a single subframe duration composed of Accordingly, in NR, a subframe has a time duration of 1 ms. However, unlike LTE, the NR subframe is an absolute reference time duration, and slots and mini-slots may be defined as time units that are the basis of actual uplink/downlink data scheduling. In this case, the number of OFDM symbols constituting the corresponding slot, y value, is determined to have a value of y=14 irrespective of the SCS value in the case of normal CP.

Accordingly, any slot is composed of 14 symbols, and depending on the transmission direction of the slot, all symbols are used for DL transmission, or all symbols are used for UL transmission, or DL portion + (gap) + It may be used in the form of a UL portion.

In addition, a mini-slot composed of fewer symbols than the slot is defined in an arbitrary numerology (or SCS), and a short time-domain scheduling interval for uplink/downlink data transmission/reception is set based on this, or slot aggregation A long time-domain scheduling interval for uplink/downlink data transmission/reception can be configured through . In particular, in the case of transmission and reception of latency-critical data such as URLLC, it is difficult to satisfy the latency requirement when scheduling is performed in 1ms (14 symbols)-based slot units defined in a numerology-based frame structure with a small SCS value such as 15kHz. For this, it is possible to define a mini-slot composed of a number of OFDM symbols smaller than the corresponding slot, and define scheduling for latency-critical data such as the corresponding URLLC based on this.

Alternatively, as described above, by multiplexing and supporting numerology having different SCS values in one NR carrier using TDM and/or FDM methods, based on the slot (or mini-slot) length defined for each numerology. A method of scheduling data according to latency requirements is also being considered. For example, as shown in FIG. 13 below, when SCS is 60 kHz, since the symbol length is reduced by about 1/4 compared to when SCS is 15 kHz, when one slot is configured with 14 OFDM symbols, the corresponding 15 kHz-based slot The length becomes 1ms, while the slot length based on 60kHz is reduced to about 0.25ms.

As such, in NR, by defining different SCS or different TTI lengths, discussion is ongoing on a method of satisfying the requirements of URLLC and eMBB.

Wider bandwidth operations

In the case of the existing LTE system, scalable bandwidth operation for an arbitrary LTC CC (Component Carrier) was supported. That is, according to the frequency 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 can configure a bandwidth of 20 MHz for one LTE CC. Transmitting/receiving capability is 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, and accordingly, it is subdivided for any NR CC as shown in FIG. 14 below. It is required to support flexible wider bandwidth operation through different bandwidth part configurations and activations for each terminal by configuring one or more bandwidth part(s) composed of the selected bandwidth.

Specifically, in NR, one or more bandwidth parts can be configured through one serving cell configured from the viewpoint of the UE, and the UE activates one DL bandwidth part and one UL bandwidth part in the corresponding serving cell to obtain uplink/downlink data It is defined to be used for sending and receiving. In addition, when multiple serving cells are configured in the corresponding UE, that is, even for the UE to which CA is applied, one DL bandwidth part and/or UL bandwidth part is activated for each serving cell and up/down using the radio resource of the corresponding serving cell. It is defined to be used for sending and receiving link data.

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

However, it can be defined to activate and use a plurality of DL and/or UL bandwidth parts at the same time according to the capability and bandwidth part(s) configuration of the UE in any serving cell, but in NR rel-15, any UE It was defined to activate and use only one DL bandwidth part and UL bandwidth part at a time.

The specific BWP configuration and activation method defined in NR is attached through TS 38.213 of appendix [1].

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 a radio communication protocol related to NR sidelink for direct communication between NR-based terminals is working in 3GPP Rel-16. The NR sidelink supports unicast and groupcast-based sidelink transmission in addition to the existing broadcast-based LTE sidelink transmission method, and also supports HARQ operation and CSI-based link adaptation for this purpose. 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) transmit/receive PSBCH (Physical Sidelink) A Physical Sidelink Control Channel (PSCCH) for transmission and reception of Sidelink Control Information (SCI) including Broadcasting Channel) and sidelink scheduling control information, a Physical Sidelink Shared Channel (PSSCH) for transmission and reception of sidelink data, as well as design for sidelink feedback A Physical Sidelink Feedback Channel (PSFCH) for HARQ ACK/NACK feedback, which is control information, was additionally designed. In addition, various HARQ ACK/NACK feedback methods based on unicast and groupcast were defined.

The present invention proposes a processing method for collision or overlap between sidelink transmission or reception and uplink transmission in an arbitrary terminal.

To this end, the present invention proposes a definition of the occurrence of a collision or overlap event between the corresponding sidelink and the uplink and a method of operating a terminal when the corresponding overlap event occurs, respectively.

Point 1. Definition of collision event between sidelink and uplink in terminal

When the uplink transmission and the sidelink transmission from any one terminal to the base station fully or partially overlap in the time axis, or when the uplink transmission and the sidelink reception fully or partially overlap in the time axis, the terminal is the uplink It is possible to detect the occurrence of a collision or overlap event between the side link and the side link, and perform the terminal operation suggested in point 2 below accordingly.

However, the overlap on the time axis is to include not only the symbols of the slot in which the actual transmission or reception is made, but also the transition time within the corresponding terminal. That is, the Tx-to-Rx transition time for switching from the transmission operation to the reception operation in the corresponding terminal, the Rx-to-Tx transition time for switching from the reception operation to the transmission operation, or a transition time for additionally switching the transmission/reception bandwidth, etc. It can be defined to include The transition time for switching the transmission/reception bandwidth is set for the corresponding terminal, or may correspond to a transition time from the activated UL bandwidth part to the sidelink bandwidth part or, conversely, a transition time from the sidelink bandwidth part to the UL bandwidth part.

The Tx-to-Rx transition time may correspond to a transition time required for switching from UL transmission to sidelink reception, and vice versa. can

Specifically, the following two cases may be defined as a collision or overlap case between the UL Tx and the sidelink Tx or the UL Tx and the sidelink Rx.

Case 1: When the preceding sidelink transmission section + BWP (Bandwidth Part) transition section (the transition section from sidelink BWP to UL BWP) and the subsequent uplink transmission section fully or partially overlap, or conversely, the preceding uplink transmission section + If the BWP transition period (transition period from UL BWP to sidelink BWP) and the subsequent sidelink transmission period fully or partially overlap.

Case 2: In case of fully overlap or partially overlap between the preceding sidelink reception section + Rx-to-Tx transition section and the subsequent uplink transmission section, or conversely, the preceding uplink transmission section + Tx-to-Rx transition section and In the case of fully or partially overlapping between the subsequent sidelink reception sections.

In this way, not only overlap in terms of simple transmission and reception, but also in consideration of the transition time between Tx/Rx or BWP in the terminal, that is, the terminal operation method proposed below only for the case that satisfies the time requirement in consideration of the processing time in the terminal. It can be defined to be applied.

Point 2. Terminal operation plan in case of collision or overlap between uplink and sidelink

Method 1: How to define priority for a specific link

According to this method, when an overlap occurs between uplink transmission and sidelink transmission or reception, that is, when an event corresponding to case 1 or case 2 occurs, the terminal prioritizes a specific link and performs the transmission or reception and , it can be defined to drop the transmission or reception of other links. That is, when an event corresponding to case 1 or case 2 occurs in any one slot or consecutive slots, it can be defined to give priority to transmission or reception in a specific link. For example, it may be defined that uplink transmission to the base station is prioritized over sidelink transmission/reception. In this case, the terminal preferentially performs the uplink transmission for the overlap occurrence cases, and the transmission or reception in the sidelink is dropped. Conversely, it can be defined to give priority to transmission/reception in the sidelink over uplink transmission to the base station. In this case, the terminal preferentially performs sidelink transmission or sidelink reception for the overlap occurrence cases, and the uplink transmission is dropped.

However, even in the case of prioritizing the transmission or reception operation on a specific link, if the setting/instruction information for transmission or reception on the priority link occurs during transmission or reception on a link with a lower priority, the corresponding terminal can be defined to stop transmission or reception in a link having a lower priority and to perform transmission or reception in a link having a higher priority. Alternatively, in this case, it may be defined to continue transmission or reception in the preceding link without applying the priority according to the link.

Method 2: How to define a priority in a link preceding transmission or reception

According to this method, it can be defined to give priority to a preceding transmission or reception operation regardless of a link, a radio channel, information, or the like. That is, when sidelink transmission or reception precedes, the corresponding sidelink transmission or reception is continued, and the subsequent uplink transmission is dropped. It can be defined to drop sidelink transmission or reception. However, when they occur simultaneously, that is, when the start symbols are the same, other methods 1, 3, 4, etc. may be applied.

Option 3: Prioritize specific channels or information

Priority may be defined for each physical channel. That is, priorities may be defined for PUSCH, PUCCH, which are uplink transmission physical channels, and PSCCH, PSSCH, and PSFCH, which are sidelink transmission and reception channels, respectively. Or uplink transmission information, that is, in the case of PUSCH, whether PUSCH transmission including only UL-SCH or PUSCH transmission including UCI (eg HARQ ACK, CSI, etc.) It can be defined to determine the priority of the sidelink PSSCH or PSFCH transmission/reception according to whether it is feedback or SR.

Method 4: Method according to the priority information indicated by the base station

A terminal operation may be determined by priority information explicitly or implicitly indicated by the base station. In this case, in the case of sidelink transmission or reception, a priority indicator value indicated through SCI or, in the case of UL transmission, a priority indicator value indicated through DCI is defined to be used to determine the priority between the UL transmission and sidelink transmission or reception can do. Specifically, SCI format 0-1 of 1-st stage SCI is defined to include a priority value of 3 bits, and DCI format 0_1 or DCI format 0_2 may be configured to include a priority indicator of 1 bit. In this case, the UE uses the priority value of the SCI as a priority value for PSSCH transmission or reception allocated by the corresponding SCI or PSFCH transmission or reception corresponding to the PSSCH, and is included in DCI format 0_1 or DCI format 0_2 It can be defined to use the assigned priority indicator as a priority value of PUSCH transmission scheduled by the corresponding DCI. In addition, in the case of PUCCH/PUSCH or SRS transmitted by DCI format 1_1 or DCI format 1_2, the 1-bit priority indicator included in the corresponding DCI format 1_1 or DCI format 1_2 is defined to be used as a priority value of the corresponding PUSCH/PUCCH or SRS. can do. That is, the priority between the corresponding sidelink transmission or reception and the uplink transmission by the priority value included in the SCI indicating any sidelink transmission or reception and the priority indicator value included in the DCI format indicating any uplink transmission can be defined to determine In this case, the priority according to the specific SCI priority value and the DCI priority indicator setting value may be set by the base station, or a fixed priority according to the corresponding values may be defined.

However, even when the DCI indicating the uplink transmission does not include the priority indicator value, the priority between the priority value included in the SCI and the uplink transmission not including the priority indicator can be determined. Priority between uplink transmission by DCI that does not include a priority value and a priority indicator may be set by the base station or a fixed priority may be defined.

Additionally, a priority between sidelink transmission/reception and uplink transmission may be defined in the form of a combination of the above methods. For example, in the form of a combination of methods 3 and 4, a priority is determined for each physical channel (eg, in the case of a PUSCH including a PSFCH and a PUCCH or UCI, it is defined to prioritize transmission of a PUSCH not including a PSSCH and UCI) For the same priority physical channel, it can be defined so that the priority is determined by the priority value included in the SCI indicating transmission or reception of the corresponding physical channel or the priority indicator included in the DCI.

Also, as in case 3, when UL BWP and sidelink BWP are identical, or when UL BWP and sidelink BWP do not overlap on the frequency axis, simultaneous TX or Rx between sidelink and uplink transmission can be defined to be supported by UE capability. In addition, it may be defined that simultaneous TX or Rx between the corresponding UL and the sidelink is configured by the base station. In this case, when equipped with simultaneous TX or Rx capability for UL and sidelink for any terminal and configured by the base station, the terminal supports simultaneous transmission and reception if it does not overlap on the frequency axis even if it overlaps in the time axis between sidelink transmission and reception and UL transmission can be defined to However, in the case of overlap on the frequency axis, the priority can be determined according to the above methods 1-4.

15 is a diagram showing the configuration of the base station 1000 according to another embodiment.

Referring to FIG. 15 , the base station 1000 according to another embodiment includes a controller 1010 , a transmitter 1020 , and a receiver 1030 .

In the sidelink transmission/reception method of the terminal necessary for carrying out the above-described present invention, the control unit 1010 is configured to give a predetermined priority when the sidelink transmission or reception in the terminal overlaps with the uplink transmission in the time domain. Controls the overall operation of the base station 1000 according to a method of performing an operation having a higher priority based on the method.

The transmitter 1020 and the receiver 1030 are used to transmit/receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

16 is a diagram showing the configuration of a user terminal 1100 according to another embodiment.

Referring to FIG. 16 , the user terminal 1100 according to another embodiment includes a receiver 1110 , a controller 1120 , and a transmitter 1130 .

The receiver 1110 receives downlink control information, data, and a message from the base station through a corresponding channel.

In addition, in the sidelink transmission/reception method of the terminal necessary for carrying out the above-described present invention, the control unit 1120 determines a predetermined priority when the sidelink transmission or reception and the uplink transmission overlap in the time domain in the terminal. Controls the overall operation of the user terminal 1100 according to a method of performing an operation with a higher priority based on .

The transmitter 1130 transmits uplink control information, data, and a message to the base station through a corresponding channel.

The above-described embodiments may be supported by standard documents disclosed in at least one of IEEE 802, 3GPP and 3GPP2, which are wireless access systems. That is, steps, configurations, and parts not described in order to clearly reveal the technical idea of 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 being, 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 rather to explain, so 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 (1)

In the sidelink transmission/reception method of the terminal,
When sidelink transmission or reception and uplink transmission overlap in a time domain in a terminal, a method of performing an operation having a higher priority based on a predetermined priority.

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