KR20230134874A - Method and apparatus for configuring sidelink slot in sidelink communication - Google Patents

Abstract

A method and apparatus for reliable transmission in sidelink communication are disclosed. A method of operating a transmitting terminal includes transmitting a first shared signal with a receiving terminal to the receiving terminal, transmitting a first signal including sidelink control information and sidelink data to the receiving terminal, and the sidelink and receiving a second signal including feedback on link data from the receiving terminal.

Description

Method and device for configuring sidelink slot in sidelink communication {METHOD AND APPARATUS FOR CONFIGURING SIDELINK SLOT IN SIDELINK COMMUNICATION}

The present invention relates to sidelink communication technology, and more specifically, to sidelink slot format technology to prevent deterioration of sidelink communication performance.

In order to process the rapid increase in wireless data after the commercialization of the 4G (4th Generation) communication system (e.g., Long Term Evolution (LTE) communication system, LTE-A (Advanced) communication system), the frequency band of the 4G communication system ( For example, a 5G (5th Generation) communication system that uses not only a frequency band below 6GHz) but also a frequency band higher than the frequency band of the 4G communication system (e.g., a frequency band above 6GHz) (e.g., NR (New A radio communication system is being considered. The 5G communication system can support enhanced Mobile BroadBand (eMBB), Ultra-Reliable and Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC).

4G communication systems and 5G communication systems may support V2X (Vehicle to everything) communication (eg, sidelink communication). V2X communication supported in cellular communication systems such as 4G communication system, 5G communication system, etc. may be referred to as "C-V2X (Cellular-Vehicle to everything) communication." V2X communication (e.g., C-V2X communication) may include V2V (Vehicle to Vehicle) communication, V2I (Vehicle to Infrastructure) communication, V2P (Vehicle to Pedestrian) communication, V2N (Vehicle to Network) communication, etc. .

Meanwhile, if time and frequency synchronization is fixed only with the S-SSB signals used for time and frequency synchronization in 5G NR sidelink communication, a problem in which the time and frequency difference becomes larger may occur.

The purpose of the present invention to solve the above problems is to provide a method and device for configuring a slot format of a sidelink that provides direct communication between terminals.

A method of operating a transmitting terminal according to the first embodiment of the present invention for achieving the above object includes transmitting a first shared signal with a receiving terminal to the receiving terminal, and sidelink control information to the receiving terminal. information, SCI) and sidelink data, and receiving a second signal including feedback on the sidelink data from the receiving terminal, wherein the first shared signal is a signal for the receiving terminal to correct the frequency difference occurring in the link between the transmitting terminal and the receiving terminal.

Here, the method of operating the transmitting terminal further includes receiving a second shared signal with the receiving terminal from the receiving terminal, and the second shared signal may be a signal for correcting the frequency difference.

Here, the first shared signal may include a demodulation reference signal (DMRS).

Here, the step of receiving the second shared signal from the receiving terminal further includes measuring the size of the second shared signal, and determining a reception gain based on the measured size, , the reception gain may be a gain value to be reflected in the second signal.

Here, the operating method of the transmitting terminal further includes estimating the frequency difference based on the second shared signal, and correcting the frequency difference in the second signal based on the estimated frequency difference. can do.

Here, the frequency difference may be estimated based on either a time domain signal of the section in which the second shared signal is transmitted or a frequency domain signal obtained by Fourier transforming the second shared signal.

Here, the method of operating the transmitting terminal may further include estimating a channel with the receiving terminal based on the DMRS included in the second shared signal.

A method of operating a receiving terminal according to a second embodiment of the present invention for achieving the above object includes receiving a first shared signal with a transmitting terminal from the transmitting terminal, and sidelink control information from the transmitting terminal. information, SCI) and sidelink data, and transmitting a second signal including feedback on the sidelink data to the transmitting terminal, wherein the first shared signal is a signal for the receiving terminal to correct the frequency difference occurring in the link between the transmitting terminal and the receiving terminal.

Here, the method of operating the receiving terminal further includes transmitting a second shared signal with the transmitting terminal to the transmitting terminal, and the second shared signal may be a signal for correcting the frequency difference.

Here, the step of receiving the first shared signal from the transmitting terminal further includes measuring the size of the first shared signal, and determining a reception gain based on the measured size, , the reception gain may be a gain value to be reflected in the first signal.

Here, the operating method of the receiving terminal further includes estimating the frequency difference based on the first shared signal, and correcting the frequency difference in the first signal based on the estimated frequency difference. can do.

Here, the frequency difference may be estimated based on either a time domain signal of the section in which the first shared signal is transmitted or a frequency domain signal obtained by Fourier transforming the first shared signal.

Here, the second shared signal may include a demodulation reference signal (DMRS).

Here, the method of operating the receiving terminal may further include the step of supplementing channel estimation with the transmitting terminal based on the DMRS included in the second shared signal.

A receiving terminal according to a third embodiment of the present invention for achieving the above object includes a processor, a memory that electronically communicates with the processor, and instructions stored in the memory. It includes, when the instructions are executed by the processor, the instructions cause the receiving terminal to receive a first shared signal with the transmitting terminal from the transmitting terminal, and to receive sidelink control information from the transmitting terminal. information, SCI) and sidelink data, and transmitting a second signal including feedback for the sidelink data to the transmitting terminal, wherein the first shared signal is a signal for the receiving terminal to correct the frequency difference occurring in the link between the transmitting terminal and the receiving terminal.

Here, it operates to cause a step of transmitting a second shared signal with the transmitting terminal to the transmitting terminal, and the second shared signal may be a signal for correcting the frequency difference.

Here, when receiving the first shared signal from the transmitting terminal, the step includes measuring the size of the first shared signal and determining a reception gain based on the measured size. It operates to do so, and the reception gain may be a gain value to be reflected in the first signal.

Here, the instructions may operate to cause the receiving terminal to estimate the frequency difference based on the first shared signal, and to correct the frequency difference in the first signal based on the estimated frequency difference. You can.

Here, the frequency difference may be estimated based on either a time domain signal of the section in which the first shared signal is transmitted or a frequency domain signal obtained by Fourier transforming the first shared signal.

Here, the commands may operate to cause the receiving terminal to supplement channel estimation with the transmitting terminal based on a demodulation reference signal (DMRS) included in the second shared signal.

According to the present application, when configuring the slot format of a side link that provides direct communication between terminals, the first symbol is used as a signal containing a signal previously shared between communication entities, thereby eliminating the frequency difference that may occur in the link between terminals. can do. Additionally, it is possible to prevent deterioration in communication performance of side links caused by frequency differences. Therefore, the performance of sidelink communication can be improved.

Figure 1 is a conceptual diagram showing scenarios of V2X communication.
Figure 2 is a conceptual diagram showing a first embodiment of a cellular communication system.
Figure 3 is a block diagram showing a first embodiment of a communication node constituting a cellular communication system.
Figure 4 is a conceptual diagram illustrating an embodiment of a sidelink communication scenario.
Figure 5 is a conceptual diagram showing a first embodiment of a sidelink slot format.
Figure 6 is a conceptual diagram showing a second embodiment of the sidelink slot format.
Figure 7 is a conceptual diagram showing a third embodiment of the sidelink slot format.
Figure 8 is a conceptual diagram showing a fourth embodiment of the sidelink slot format.
Figure 9 is a conceptual diagram showing a fifth embodiment of the sidelink slot format.
Figure 10 is a conceptual diagram showing a sixth embodiment of the sidelink slot format.
Figure 11 is a conceptual diagram showing the seventh embodiment of the sidelink slot format.
Figure 12 is a block diagram showing automatic gain control (AGC) and automatic frequency correction (AFC) of a sidelink receiver.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. The term “and/or” includes any of a plurality of related stated items or a combination of a plurality of related stated items.

In embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Additionally, in embodiments of the present application, “one or more of A and B” may mean “one or more of A or B” or “one or more of combinations of one or more of A and B.”

In embodiments of the present application, (re)transmit can mean “transmit”, “retransmit”, or “transmit and retransmit”, and (re)set can mean “set”, “reset”, or “set and may mean “reset”, (re)connect may mean “connect”, “reconnect”, or “connect and reconnect”, and (re)connect may mean “connect”, “reconnect”, or “ It can mean “connection and reconnection.”

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an idealized or excessively formal sense. No.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings. In order to facilitate overall understanding when describing the present invention, the same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

Figure 1 is a conceptual diagram illustrating scenarios of V2X (Vehicle to everything) communication.

Referring to Figure 1, V2X communication may include V2V (Vehicle to Vehicle) communication, V2I (Vehicle to Infrastructure) communication, V2P (Vehicle to Pedestrian) communication, V2N (Vehicle to Network) communication, etc. V2X communication may be supported by a cellular communication system (e.g., a cellular communication network) 140, and V2X communication supported by the cellular communication system 140 is "C-V2X (Cellular-Vehicle to everything) communication. It can be referred to as ". The cellular communication system 140 is a 4th Generation (4G) communication system (e.g., Long Term Evolution (LTE) communication system, Advanced (LTE-A) communication system), a 5th Generation (5G) communication system (e.g., NR (New Radio) communication system), etc.

V2V communication is communication between vehicle #1 (100) (e.g., a communication node located in vehicle #1 (100)) and vehicle #2 (110) (e.g., a communication node located in vehicle #1 (100)) It can mean. Driving information (e.g., speed, heading, time, position, etc.) may be exchanged between vehicles 100 and 110 through V2V communication. Autonomous driving (eg, platooning) may be supported based on driving information exchanged through V2V communication. V2V communication supported by the cellular communication system 140 may be performed based on sidelink communication technology (e.g., ProSe (Proximity based Services) communication technology, D2D (Device to Device) communication technology). . In this case, communication between vehicles 100 and 110 may be performed using a sidelink channel.

V2I communication may refer to communication between vehicle #1 (100) and infrastructure (eg, road side unit (RSU)) 120 located at the roadside. The infrastructure 120 may be a traffic light or street light located on the roadside. For example, when V2I communication is performed, communication may be performed between a communication node located in vehicle #1 (100) and a communication node located at a traffic light. Driving information, traffic information, etc. can be exchanged between vehicle #1 (100) and infrastructure (120) through V2I communication. V2I communication supported by the cellular communication system 140 may be performed based on sidelink communication technology (eg, ProSe communication technology, D2D communication technology). In this case, communication between vehicle #1 (100) and infrastructure 120 may be performed using a sidelink channel.

V2P communication may mean communication between vehicle #1 (100) (e.g., a communication node located in vehicle #1 (100)) and a person 130 (e.g., a communication node possessed by the person 130). You can. Through V2P communication, driving information of vehicle #1 (100) and movement information of person (130) (e.g., speed, direction, time, location, etc.) are exchanged between vehicle #1 (100) and person (130). It may be that the communication node located in vehicle #1 (100) or the communication node possessed by the person (130) determines a dangerous situation based on the acquired driving information and movement information and generates an alarm indicating danger. . V2P communication supported by the cellular communication system 140 may be performed based on sidelink communication technology (eg, ProSe communication technology, D2D communication technology). In this case, communication between the communication node located in vehicle #1 100 or the communication node possessed by the person 130 may be performed using a sidelink channel.

V2N communication may refer to communication between vehicle #1 (100) (e.g., a communication node located in vehicle #1 (100)) and a cellular communication system (e.g., a cellular communication network) 140. V2N communication can be performed based on 4G communication technology (e.g., LTE communication technology and LTE-A communication technology specified in 3GPP standards), 5G communication technology (e.g., NR communication technology specified in 3GPP standards), etc. there is. In addition, V2N communication is a communication technology specified in the IEEE (Institute of Electrical and Electronics Engineers) 702.11 standard (e.g., WAVE (Wireless Access in Vehicular Environments) communication technology, WLAN (Wireless Local Area Network) communication technology, etc.), IEEE It may be performed based on communication technology specified in the 702.15 standard (e.g., WPAN (Wireless Personal Area Network), etc.).

Meanwhile, the cellular communication system 140 supporting V2X communication may be configured as follows.

Figure 2 is a conceptual diagram showing a first embodiment of a cellular communication system.

Referring to FIG. 2, the cellular communication system may include an access network, a core network, etc. The access network may include a base station 210, a relay 220, and user equipment (UE) 231 to 236. UEs 231 to 236 may be communication nodes located in vehicles 100 and 110 of FIG. 1, communication nodes located in infrastructure 120 of FIG. 1, communication nodes possessed by person 130 of FIG. 1, etc. If the cellular communication system supports 4G communication technology, the core network includes a serving-gateway (S-GW) 250, a packet data network (PDN)-gateway (P-GW) 260, and a mobility management entity (MME). (270), etc. may be included.

If the cellular communication system supports 5G communication technology, the core network may include a user plane function (UPF) (250), a session management function (SMF) (260), an access and mobility management function (AMF) (270), etc. You can. Alternatively, if NSA (Non-StandAlone) is supported in the cellular communication system, the core network consisting of S-GW (250), P-GW (260), MME (270), etc. uses not only 4G communication technology but also 5G communication technology. can also support, and the core network consisting of UPF (250), SMF (260), AMF (270), etc. can support not only 5G communication technology but also 4G communication technology.

Additionally, if the cellular communication system supports network slicing technology, the core network may be divided into a plurality of logical network slices. For example, a network slice that supports V2X communication (e.g., V2V network slice, V2I network slice, V2P network slice, V2N network slice, etc.) may be set, and V2X communication is performed on the V2X network slice set in the core network. can be supported by

Communication nodes that make up the cellular communication system (e.g., base station, relay, UE, S-GW, P-GW, MME, UPF, SMF, AMF, etc.) use CDMA (code division multiple access) technology, WCDMA (wideband) CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier) -FDMA technology, NOMA (Non-orthogonal Multiple Access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, and SDMA (Space Division Multiple Access) ) Communication can be performed using at least one communication technology among the technologies.

Communication nodes constituting the cellular communication system (e.g., base station, relay, UE, S-GW, P-GW, MME, UPF, SMF, AMF, etc.) may be configured as follows.

Figure 3 is a block diagram showing a first embodiment of a communication node constituting a cellular communication system.

Referring to FIG. 3, the communication node 300 may include at least one processor 310, a memory 320, and a transmitting and receiving device 330 that is connected to a network and performs communication. Additionally, the communication node 300 may further include an input interface device 340, an output interface device 350, a storage device 360, etc. Each component included in the communication node 300 is connected by a bus 370 and can communicate with each other.

However, each component included in the communication node 300 may be connected through an individual interface or individual bus centered on the processor 310, rather than the common bus 370. For example, the processor 310 may be connected to at least one of the memory 320, the transmission and reception device 330, the input interface device 340, the output interface device 350, and the storage device 360 through a dedicated interface. .

The processor 310 may execute a program command stored in at least one of the memory 320 and the storage device 360. The processor 310 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 320 and the storage device 360 may be comprised of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 320 may be comprised of at least one of read only memory (ROM) and random access memory (RAM).

Referring again to FIG. 2, in the communication system, the base station 210 may form a macro cell or small cell and may be connected to the core network through ideal backhaul or non-ideal backhaul. The base station 210 may transmit signals received from the core network to the UEs 231 to 236 and the relay 220, and may transmit signals received from the UEs 231 to 236 and the relay 220 to the core network. . UE #1, #2, #4, #5, and #6 (231, 232, 234, 235, 236) may belong to the cell coverage of the base station 210. UE #1, #2, #4, #5, and #6 (231, 232, 234, 235, 236) can be connected to the base station 210 by performing a connection establishment procedure with the base station 210. . UE #1, #2, #4, #5, and #6 (231, 232, 234, 235, 236) can communicate with the base station 210 after being connected to the base station 210.

The relay 220 may be connected to the base station 210 and may relay communication between the base station 210 and UE #3 and #4 (233, 234). The relay 220 may transmit signals received from the base station 210 to UE #3 and #4 (233, 234), and may transmit signals received from UE #3 and #4 (233, 234) to the base station 210. can be transmitted to. UE #4 234 may belong to the cell coverage of the base station 210 and the cell coverage of the relay 220, and UE #3 233 may belong to the cell coverage of the relay 220. That is, UE #3 233 may be located outside the cell coverage of the base station 210. UE #3 and #4 (233, 234) can be connected to the relay 220 by performing a connection establishment procedure with the relay 220. UE #3 and #4 (233, 234) may communicate with the relay 220 after being connected to the relay 220.

The base station 210 and the relay 220 use MIMO (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.) communication technology, coordinated multipoint (CoMP) communication technology, Carrier Aggregation (CA) communication technology, unlicensed band communication technology (e.g., Licensed Assisted Access (LAA), enhanced LAA (eLAA)), sidelink communication technology (e.g., ProSe communication technology, D2D communication) technology), etc. UE #1, #2, #5, and #6 (231, 232, 235, 236) may perform operations corresponding to the base station 210, operations supported by the base station 210, etc. UE #3 and #4 (233, 234) may perform operations corresponding to the relay 220, operations supported by the relay 220, etc.

Here, the base station 210 is a NodeB, an evolved NodeB, a base transceiver station (BTS), a radio remote head (RRH), a transmission reception point (TRP), a radio unit (RU), and an RSU ( It may be referred to as a road side unit, a radio transceiver, an access point, an access node, etc. Relay 220 may be referred to as a small base station, relay node, etc. UEs 231 to 236 are terminals, access terminals, mobile terminals, stations, subscriber stations, mobile stations, and portable subscriber stations. It may be referred to as a subscriber station, a node, a device, an on-broad unit (OBU), etc.

Meanwhile, communication between UE #5 235 and UE #6 236 may be performed based on cyclic link communication technology (eg, ProSe communication technology, D2D communication technology). Sidelink communication may be performed based on a one-to-one method or a one-to-many method. When V2V communication is performed using Cylink communication technology, UE #5 (235) may indicate a communication node located in vehicle #1 (100) of FIG. 1, and UE #6 (236) may indicate a communication node located in vehicle #1 (100) of FIG. 1. The communication node located in vehicle #2 (110) can be indicated. When V2I communication is performed using Cyclink communication technology, UE #5 (235) may indicate a communication node located in vehicle #1 (100) of FIG. 1, and UE #6 (236) may indicate a communication node located in vehicle #1 (100) of FIG. 1. A communication node located in the infrastructure 120 may be indicated. When V2P communication is performed using Cyclink communication technology, UE #5 (235) may indicate a communication node located in vehicle #1 (100) of FIG. 1, and UE #6 (236) may indicate a communication node located in vehicle #1 (100) of FIG. 1. The communication node possessed by the person 130 can be indicated.

Scenarios to which sidelink communication is applied can be classified as shown in Table 1 below according to the locations of UEs (e.g., UE #5 (235), UE #6 (236)) participating in sidelink communication. For example, the scenario for sidelink communication between UE #5 (235) and UE #6 (236) shown in FIG. 2 may be sidelink communication scenario #C.

Meanwhile, the channels used in sidelink communication between UE #5 (235) and UE #6 (236) are PSSCH (Physical Sidelink Shared Channel), PSCCH (Physical Sidelink Control Channel), PSDCH (Physical Sidelink Discovery Channel), and PSBCH ( Physical Sidelink Broadcast Channel), etc. PSSCH can be used for transmission and reception of sidelink data, and can be set to UE (e.g., UE #5 (235), UE #6 (236)) by higher layer signaling. PSCCH can be used for transmission and reception of sidelink control information (SCI) and can be set to UE (e.g., UE #5 (235), UE #6 (236)) by higher layer signaling. there is.

PSDCH can be used for discovery procedures. For example, the discovery signal may be transmitted via PSDCH. PSBCH can be used for transmission and reception of broadcast information (eg, system information). Additionally, a demodulation reference signal (DMRS), a synchronization signal, etc. may be used in sidelink communication between UE #5 (235) and UE #6 (236). The synchronization signal may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS).

Meanwhile, sidelink transmission mode (TM) can be classified into sidelink TM #1 to #4 as shown in Table 2 below.

If sidelink TM #3 or #4 is supported, UE #5 (235) and UE #6 (236) each perform sidelink communication using the resource pool set by the base station 210. You can. A resource pool can be set up for each of sidelink control information or sidelink data.

A resource pool for sidelink control information may be set based on an RRC signaling procedure (e.g., dedicated RRC signaling procedure, broadcast RRC signaling procedure). The resource pool used for receiving sidelink control information can be set by the broadcast RRC signaling procedure. If sidelink TM #3 is supported, the resource pool used for transmission of sidelink control information can be set by a dedicated RRC signaling procedure. In this case, sidelink control information may be transmitted through resources scheduled by the base station 210 within a resource pool established by a dedicated RRC signaling procedure. If sidelink TM #4 is supported, the resource pool used for transmission of sidelink control information can be set by a dedicated RRC signaling procedure or a broadcast RRC signaling procedure. In this case, the sidelink control information is autonomously selected by the UE (e.g., UE #5 (235), UE #6 (236)) within the resource pool established by the dedicated RRC signaling procedure or the broadcast RRC signaling procedure. Can be transmitted through resources.

If sidelink TM #3 is supported, the resource pool for transmission and reception of sidelink data may not be set. In this case, sidelink data can be transmitted and received through resources scheduled by the base station 210. If sidelink TM #4 is supported, the resource pool for transmission and reception of sidelink data can be established by a dedicated RRC signaling procedure or a broadcast RRC signaling procedure. In this case, the sidelink data uses resources autonomously selected by the UE (e.g., UE #5 (235), UE #6 (236)) within the resource pool established by the RRC signaling procedure or the broadcast RRC signaling procedure. It can be sent and received through.

Next, sidelink communication methods will be described. Even when a method (e.g., transmission or reception of a signal) performed in a first communication node among communication nodes is described, the corresponding second communication node is described as a method (e.g., transmitting or receiving a signal) corresponding to the method performed in the first communication node. For example, reception or transmission of a signal) can be performed. That is, when the operation of UE #1 (e.g., vehicle #1) is described, the corresponding UE #2 (e.g., vehicle #2) can perform the operation corresponding to the operation of UE #1. there is. Conversely, when the operation of UE #2 is described, the corresponding UE #1 may perform the operation corresponding to the operation of UE #2. In the embodiments described below, the operation of the vehicle may be the operation of a communication node located in the vehicle.

In embodiments, signaling may be one or a combination of two or more of upper layer signaling, MAC signaling, and PHY (physical) signaling. Messages used for upper layer signaling may be referred to as “upper layer messages” or “higher layer signaling messages.” Messages used for MAC signaling may be referred to as “MAC messages” or “MAC signaling messages.” Messages used for PHY signaling may be referred to as “PHY messages” or “PHY signaling messages.” Upper layer signaling may refer to transmission and reception operations of system information (e.g., master information block (MIB), system information block (SIB)) and/or RRC messages. MAC signaling may refer to the transmission and reception operations of a MAC CE (control element). PHY signaling may refer to the transmission and reception of control information (e.g., downlink control information (DCI), uplink control information (UCI), and SCI).

The sidelink signal may be a synchronization signal and a reference signal used for sidelink communication. For example, the synchronization signal may be a synchronization signal/physical broadcast channel (SS/PBCH) block, a sidelink synchronization signal (SLSS), a primary sidelink synchronization signal (PSSS), a secondary sidelink synchronization signal (SSSS), etc. The reference signal may be a channel state information-reference signal (CSI-RS), DMRS, phase tracking-reference signal (PT-RS), cell specific reference signal (CRS), sounding reference signal (SRS), discovery reference signal (DRS), etc. You can.

The sidelink channel may be PSSCH, PSCCH, PSDCH, PSBCH, physical sidelink feedback channel (PSFCH), etc. Additionally, the sidelink channel may refer to a sidelink channel that includes a sidelink signal mapped to specific resources within the corresponding sidelink channel. Sidelink communication may support broadcast service, multicast service, groupcast service, and unicast service.

Sidelink communication can be performed based on a single SCI method or a multi SCI method. When a single SCI method is used, data transmission (e.g., sidelink data transmission, sidelink-shared channel (SL-SCH) transmission) is performed based on one SCI (e.g., 1st-stage SCI). You can. When a multi-SCI method is used, data transmission may be performed using two SCIs (eg, 1st-stage SCI and 2nd-stage SCI). SCI may be transmitted via PSCCH and/or PSSCH. If a single SCI method is used, SCI (eg, 1st-stage SCI) may be transmitted on PSCCH. When a multiple SCI method is used, 1st-stage SCI can be transmitted on PSCCH, and 2nd-stage SCI can be transmitted on PSCCH or PSSCH. 1st-stage SCI may be referred to as “first stage SCI” and 2nd-stage SCI may be referred to as “second stage SCI.” The first level SCI format may include SCI format 1-A, and the second level SCI format may include SCI format 2-A and SCI format 2-B.

The first stage SCI includes priority information, frequency resource assignment information, time resource allocation information, resource reservation period information, demodulation reference signal (DMRS) pattern information, and second stage SCI. It may include one or more information elements among format information, beta_offset indicator, number of DMRS ports, and modulation and coding scheme (MCS) information. The second stage SCI requires HARQ processor ID (identifier), RV (redundancy version), source ID, destination ID, CSI request information, zone ID, and communication range requirements (communication It may contain one or more information elements among the range requirements.

Next, in 5G sidelink communication between terminals existing inside/outside the coverage area of the base station, the priority of sidelink communication according to the environment of each terminal can be explained.

Figure 4 is a conceptual diagram illustrating an embodiment of a sidelink communication scenario.

Referring to FIG. 4, the first base station 411 can provide services by forming the first coverage 410, and the second base station 421 can provide services by forming the second coverage 420. there is. The first base station 411 can provide services through terminal A (412) within the first coverage 410, and the second base station 421 can provide services through terminal B (422) and The service can be provided through terminal C (423). Terminal A (412) can synchronize with the first base station (411). Terminal B (422) and terminal C (423) can synchronize with the second base station 421 (level 2).

Meanwhile, since terminal D (431) is outside the range of the first coverage 410 and the second coverage 420, it may be difficult to synchronize with the first base station 411 or the second base station 421. Therefore, terminal D (431) sets terminal A (412) as the reference synchronization (sync reference) terminal and uses the sidelink synchronization signal block (S-SSB) transmitted by terminal A (412). Can synchronize (level 3). Since terminal E (432) exists within the first coverage (410) or second coverage (420), it cannot be connected to terminals that are synchronized to the first base station (411) or the second base station (421). Therefore, terminal E (432), like terminal D (431), can secure synchronization by connecting to a terminal that has set terminal A (412) or terminal B (422) as the reference synchronization terminal outside of coverage (level 7).

On the other hand, terminal F (442) is outside the range of the first coverage 410 and the second coverage 420, but can secure synchronization within the coverage 430 of the GNSS network 441 that provides absolute time synchronization ( Level 5). And terminal G (443), which is connected to terminal F (442) but is outside the third coverage (430), can set terminal F (442) as the reference synchronization terminal. Therefore, terminal G (443) can achieve synchronization using the sidelink S-SSB transmitted by terminal F (442) (level 6). That is, terminal G (451) can use terminal F (442), which is synchronized to the GNSS network, as a reference synchronization terminal, rather than a terminal that is synchronized to the first base station (411) like terminal A (412).

Terminal H (452) can use terminal G (451) as a reference synchronization terminal. Terminal H (452) may exist outside the first coverage 410, second coverage 420, and GNSS coverage 430, and may exist outside the first coverage 410, second coverage 420, and GNSS coverage. It may have the same priority as the terminal E (432) in that the terminal that exists inside and is synchronized with 430 is used as the reference synchronization terminal (level 7).

Meanwhile, if the terminal does not belong to any coverage and there is no reference synchronization terminal, the terminal's own clock can be used as a standard for synchronization. For example, terminal I 461 does not belong to the first coverage 410, the second coverage 420, and the GNSS coverage 430, and there is no terminal for reference synchronization, so its own clock can be used as a synchronization reference. . Therefore, when using the own clock as a synchronization standard, it can have the lowest priority because it can be used when all of the above-mentioned conditions are not satisfied (level 8). However, terminal J (462) can use terminal I (461), which uses the terminal's internal clock as a synchronization signal, as a reference synchronization terminal, so it can have the same priority as terminal E (432) and terminal H (452). Yes (level 7).

Figure 5 is a conceptual diagram showing a first embodiment of a sidelink slot format.

Referring to FIG. 5, the first embodiment of the 5G NR-based sidelink slot format may be a slot format using a normal cyclic prefix (CP) consisting of 14 OFDM symbols per slot. The slot format according to the first embodiment may be composed of AGC (511), DMRS (512), PSSCH (513), PSCCH (514), and guard period (515). PSCCH 514 may exist in three OFDM symbol sections. The PSSCH 513 may be composed of 12 OFDM symbols transmitted by the DMRS 112 in 4 OFDM symbol intervals. In the first OFDM symbol, an AGC section 511 may be located in which the signal transmitted in the second OFDM symbol is copied and transmitted in order to stably perform an automatic gain control (AGC) operation in the receiving terminal. A guard interval 515 may be located in the last OFDM symbol interval to switch between transmission and reception.

Figure 6 is a conceptual diagram showing a second embodiment of the sidelink slot format.

Referring to FIG. 6, the second embodiment of the 5G NR-based sidelink slot format may be a slot format using a normal CP consisting of 14 OFDM symbols per slot. PSCCH 614 may exist in two OFDM symbol intervals. The PSSCH 613 may be composed of 11 OFDM symbols in which the DMRS 612 is transmitted in 2 OFDM symbol intervals. In the first OFDM symbol, an AGC section 611 may be located in which the signal transmitted in the second OFDM symbol is copied and transmitted in order to stably perform the AGC operation in the receiving terminal. A guard interval 615 may be located in the second-to-last OFDM symbol to switch between transmission and reception.

Figure 7 is a conceptual diagram showing a third embodiment of the sidelink slot format.

Referring to FIG. 7, the third embodiment of the 5G NR-based sidelink slot format may include PSFCH and may be a slot format using a normal CP consisting of 14 OFDM symbols per slot. PSCCH 714 may exist in two OFDM symbol intervals. The PSSCH 713 may be composed of 9 OFDM symbols transmitted by the DMRS 712 in 2 OFDM symbol intervals. In the first OFDM symbol used by the transmitting terminal, a first AGC section 711-1 may be located in which the signal transmitted in the second OFDM symbol is copied and transmitted in order to stably perform the AGC operation in the receiving terminal. Additionally, a first guard interval 716-1 for switching between reception and transmission may be located in the OFDM symbol section immediately after the transmitting terminal completes signal transmission.

Meanwhile, in the first OFDM symbol interval used by the receiving terminal when transmitting - the OFDM symbol interval following the first AGC interval (711-1) - the PSFCH symbol is copied and transmitted so that the transmitting terminal can stably perform the AGC operation. a second AGC section (711-2), a PSFCH (715) including feedback information for transmitting the demodulation result of the PSSCH from the receiving terminal to the transmitting terminal, and a second AGC section (711-2) required for the next operation immediately after the receiving terminal completes transmission. The second protection interval 716-2 for the protection interval section may be located sequentially.

Figure 8 is a conceptual diagram showing a fourth embodiment of the sidelink slot format.

Referring to FIG. 8, the fourth embodiment of the 5G NR-based sidelink slot format transmits S-SSB, a PSBCH (811) that transmits a message including system parameters for the sidelink, and two types of S-PSS. S-PSS (812) transmitted in the second and third OFDM symbols of the slot by selecting one of the sequences and using 127 subcarriers. Selecting one of 336 types of S-SSS sequences and using 127 subcarriers Thus, it may be composed of an S-SSS 813 transmitted in the fourth and fifth OFDM symbols of the slot, and a guard interval 814 located in the last OFDM symbol.

In common in the embodiments of the 5G NR sidelink slot format of FIGS. 5 to 8 described above, the first OFDM symbol during transmission is an interval for AGC, and immediately after transmission is completed, the OFDM symbol is determined as a guard interval and no data is allocated. You can confirm that it is not. The following embodiments may include a description of how to utilize the OFDM symbol interval set for AGC.

AGC is optimal for the input of the receiving terminal ADC (analog-to-digital converter) by reflecting the gain to the subsequent received signal according to the signal size measured at a past point in time (e.g., received signal strength indicator, RSSI). This may be a way to have a level of. The input level of the signal optimized through ACG minimizes quantization noise while passing through the ADC, thereby achieving optimal signal quality and enabling highly reliable reception.

If there is no signal or the received signal level is very low right before the receiving terminal receives the signal it wants to receive, a very large gain may be set to the receiving terminal through the AGC operation. In addition, when a signal with a power level sufficient for actual reception is received, the received signal exceeds the range of the ADC due to a very large gain, which may cause the signal to be distorted and the signal quality to rapidly deteriorate.

On the other hand, when the receiving terminal receives a signal with a very high signal level immediately before receiving the signal it wants to receive, a very small gain may be set to the receiving terminal by the AGC operation. In addition, when a signal with a power level appropriate for actual reception is received, the received signal has a level that is too small considering the ADC input range due to a very small gain, which significantly reduces the number of effective bits while passing through the ADC, resulting in a significant increase in quantization noise. This may cause signal quality to deteriorate.

Therefore, in order to solve this problem and achieve smooth AGC operation in the sidelink, it is necessary to improve the conventional AGC operation used in cases where there is a signal that can continuously maintain link formation, such as in the case of communication between a base station and a terminal. There is. In other words, the continuous AGC operation is changed to perform an intermittent AGC operation to suit the transmission and reception of intermittent signals. For example, by allowing the receiving terminal to maintain the gain level used when successfully receiving the PSCCH/PSSCH transmitted from the transmitting terminal for a certain period of time, the gain is rapidly increased in the section where there is no transmission signal, thereby reducing the risk of excessive input signals. Clipping problem can be solved.

In the 5G NR system, in order to smoothly perform AGC operation, a method of copying and using the signal of the second symbol to the first symbol of the slot can be used. Referring again to FIG. 8, the fourth embodiment of the sidelink slot format may be a slot format that uses a PSBCH signal for the first OFDM symbol. The reason why the slot format of the fourth embodiment of the sidelink slot format has the above-described structure may be that if the second OFDM symbol signal is used, an error may occur when receiving a synchronization signal through S-PSS.

Referring again to FIG. 7, the third embodiment of the sidelink slot format may be a slot format in which an ACG symbol is assigned to the OFDM symbol immediately preceding the PSFCH transmission symbol and the signal of the PSFCH transmission symbol is copied and used. The slot format of the third embodiment of the sidelink slot format requires the receiving terminal to perform PSCCH and PSSCH reception operations in the previous OFDM symbol period and then switch to transmission operations through PSFCH, and the transmitting terminal must perform PSCCH and PSSCH reception operations in the previous OFDM symbol period. Since the PSSCH transmission operation must be performed and then switched to the reception operation in the PFSCH symbol period, a guard period period and an ACG period may be added. Therefore, in the slot format of the 5G NR sidelink, copying the signal of the next OFDM symbol section to the AGC section may be an option to optimize the operation of AGC. Stable AGC operation can be expected even in 5G NR sidelinks where intermittent transmission occurs.

Referring back to FIG. 4, in 5G NR sidelink communication that occurs intermittently in various synchronous environments, such as an embodiment of a 5G sidelink service scenario, another problem of the communication link in addition to AGC operation may be AFC operation. Since the terminal typically uses an oscillator with lower frequency precision than the base station, the terminal continuously corrects the frequency difference using signals transmitted from the base station (e.g., DMRS or PT-RS) to achieve high frequency precision. can be secured. An operation to correct the frequency difference of the terminal may be an automatic frequency control (AFC) operation. Terminal A (412), terminal B (422), terminal C (423), and terminal F (442) directly use the signals of the first base station 411, the second base station 421, and the GNSS network 441. Frequency synchronization is possible. Therefore, since it can operate within a certain error (for example, up to ±1ppm), OFDM performance deterioration due to frequency difference may not occur. However, terminal A (412), terminal B (422), terminal C (423), and terminal F (442) are set as the reference synchronization terminal, or terminal I (461), which operates with a separate clock, is set as the reference synchronization terminal. In this case, the frequency difference may increase. In particular, when time and frequency synchronization is corrected only with SSSB signals used for time and frequency synchronization in 5G NR sidelink, the time and frequency difference may become larger.

Therefore, in 5G NR sidelink communication, a method and device may be needed to secure stable sidelink call quality so as to secure the performance of the AFC operation as well as the performance of the AGC operation.

Figure 9 is a conceptual diagram showing a fifth embodiment of the sidelink slot format.

Referring to FIG. 9, the sidelink slot format that provides direct communication between terminals, unlike the sidelink slot format in which the first OFDM symbol is composed of an AGC section in the first embodiment of FIG. 5, uses signals previously shared between communication entities. It may be composed of signals including: The configuration information of the sidelink slot format of the fifth embodiment may be set in the transmitting and receiving terminals by the base station through higher layer signaling (eg, RRC signaling).

Figure 10 is a conceptual diagram showing a sixth embodiment of the sidelink slot format.

Referring to FIG. 10, the sidelink slot format that provides direct communication between terminals, unlike the sidelink slot format in which the first OFDM symbol is composed of an AGC section in the second embodiment of FIG. 6, uses signals previously shared between communication entities. It may be composed of signals including: The configuration information of the sidelink slot format of the sixth embodiment may be set in the transmitting and receiving terminals by the base station through higher layer signaling (eg, RRC signaling).

Referring again to FIGS. 9 and 10, signals previously shared between communication entities may be set in the transmitting and receiving terminals through higher layer signaling (eg, RRC signaling). Signals previously shared between communication entities can be generated based on DMRS used for channel estimation. The DMRS port may be set in the transmitting and receiving terminal by higher layer signaling (eg, RRC signaling) by the base station. Alternatively, the transmitting terminal may indicate the DMRS port to the receiving terminal through SCI.

The following embodiments may include a description of the characteristics of the slot format of the sidelink that uses DMRS as a signal previously shared between communication entities.

The signal previously shared between communication entities assigned to the first OFDM symbol of a slot may be different from the signal stored in the second OFDM symbol. Therefore, differences may occur in the received signal level measured for the AGC operation of the receiving terminal. However, the technique of copying the signal of the second OFDM symbol and transmitting it to the first OFDM symbol can operate effectively in the ideal case where only one PSCCH/PSSCH exists at the time, but may not be effective in an actual communication environment. That is, there may be a plurality of PSCCH/PSSCH in the bandwidth part (BWP) that supports sidelink. Since the reception bandwidth of the receiving terminal may be sufficiently larger than the band part, the signal level measured in the first OFDM symbol is not comprised of only the PSCCH/PSSCH that the receiving terminal wishes to receive, but of all signals within the bandwidth of the receiving terminal at that point in time. You can. Therefore, in the case of a technology that copies the signal of the second OFDM symbol and transmits it in the first symbol section, the AGC operation based on the signal size measured in the first symbol section may not be optimized for the level of signals received in the second symbol section. Since errors in AGC operation may occur even when a random signal previously shared between communication entities is used in the first OFDM symbol, the performance of AGC operation using a shared random signal may not deteriorate.

Even if a signal previously shared between communication entities is not used in the first OFDM symbol of a slot, the receiving terminal can derive phase information of the received channel using DMRS and demodulate the PSCCH/PSSCH. However, in the case of a terminal with poor frequency precision, the frequency difference between the transmitting terminal and the receiving terminal may increase over time, and as the number of hops between terminals increases, the frequency difference continues to increase, so the channel phase can be adjusted using DMRS. Problems that exceed the range that can be estimated may occur. In particular, when correcting the frequency difference using intermittently transmitted PSCCH/PSSCH and DMRS, a problem may occur in which the frequency difference between terminals exceeds the trackable range.

Therefore, if the signal allocated to the first OFDM symbol of the slot is a signal previously shared between communication entities, the receiving terminal can directly extract the frequency difference of the link between communication terminals in advance before the PSCCH/PSSCH signal is input. Therefore, the frequency difference between the transmitting terminal and the receiving terminal can be maintained within the frequency difference allowed in the channel estimation step through DMRS at the time the PSCCH/PSSCH signal is input by reflecting the pre-extracted frequency difference between direct communication terminals in the AFC. . In particular, the fifth and sixth embodiments of the above-described sidelink slot format are suitable for situations in which frequency differences persist over time, situations in which the target for performing sidelink communication that provides direct communication is continuously changed, or reference synchronization. It can be effective in situations where the frequency difference changes arbitrarily due to changes.

Figure 11 is a conceptual diagram showing the seventh embodiment of the sidelink slot format.

Referring to FIG. 11, the sidelink slot format that provides direct communication between terminals is different from the sidelink slot format in which the first and twelfth OFDM symbols are composed of AGC sections in the third embodiment of FIG. 7. The first and twelfth OFDM symbols are A symbol may consist of signals including signals previously shared between communication entities. The configuration information of the sidelink slot format of the seventh embodiment may be set in the transmitting and receiving terminals by the base station through higher layer signaling (eg, RRC signaling). The method and features of using a signal including a signal previously shared between communication entities in the first OFDM symbol may be the same as those described in FIGS. 9 to 10 described above.

However, in this embodiment, the transmitting terminal does not copy and use the thirteenth symbol signal (i.e., PSFCH (1115)) in the twelfth OFDM symbol, but transmits a signal previously shared between communication entities in the twelfth OFDM symbol to use the PSFCH (1115) The receiving terminal (i.e., the transmitting terminal) can correct the frequency difference. Signals previously shared between communication entities may be set in the transmitting and receiving terminals through higher layer signaling (eg, RRC signaling). DMRS, which is used for channel estimation, can be used for signals previously shared between communication entities. The DMRS port may be set in the transmitting and receiving terminal by higher layer signaling (eg, RRC signaling) by the base station. Alternatively, the transmitting terminal may indicate the DMRS port to the receiving terminal through SCI.

Figure 12 is a block diagram showing AGC and automatic frequency correction (AFC) of a sidelink receiver.

Referring to FIG. 12, the receiver may include AGC and AFC. A typical OFDM receiver can receive RF/IF signals, and has a mixer unit 1211 that multiplies the signal of the corresponding frequency component generated by the oscillator 1210, and a low-frequency signal that passes the baseband signal from the output of the mixer unit 1211. A low pass filter (LPF) 1212, a gain control unit 1213 that adjusts the signal level by reflecting the gain in the baseband signal, an ADC unit 1214 that quantizes the analog signal into a digital signal, and a digital signal. A fast Fourier transform (FFT) 1215 that converts the converted time domain signal into a frequency domain signal, a channel estimator 1216 that estimates the channel phase using DMRS, and a channel estimator It may include a demodulator 1217 that channel compensates the output signal of the fast Fourier transform unit 1215 to be received using the channel estimate phase signal of 1216 and transmits it for decoding processing.

The AGC control unit 1220 measures the size of the received signal using the time domain signal output from the ADC unit 1214 and the signal level detector 1221, which measures the size of the received signal output from the signal level meter 1221. It may be comprised of a gain determination unit 1222 that determines the gain to be reflected in the received signal, and the gain determined by the AGC control unit 1220 may be output to the gain adjustment unit 1213 and reflected in the received signal.

Meanwhile, the AFC control unit 1230 uses the frequency domain signal output from the fast Fourier transform unit 1215 to derive the phase change of the received signal, and based on this, the frequency detection unit detects the inherent frequency difference between the transmitting terminal and the receiving terminal. (1231), and a frequency determination unit 1232 that determines the frequency to be set using the detected frequency difference, and the frequency determined by the AFC control unit 1230 is output to the oscillator 1210 to provide a corrected frequency signal. can be caused to occur.

Typically, in the communication mode between the terminal and the base station, the RF/IF signal input to the terminal includes a common signal that allows all terminals within the coverage of the base station to receive, and a signal necessary in the process of communicating with a plurality of terminals simultaneously. Dedicated signals may also be included. Therefore, in a situation where a common signal and a dedicated signal coexist, the terminal may not need a separate signal for AGC operation.

On the other hand, in sidelink transmission mode for direct communication between devices, signal transmission between devices may occur intermittently. In particular, if the sidelink band part is set separately, changes in the RF/IF signal actually input to the terminal may appear significantly. Therefore, when there is no signal in the first OFDM symbol (discontinuous transmission; DTX), it may be difficult for the receiver to set an appropriate gain for the signal (e.g., PSCCH/PSSCH or PSFCH) input from the second OFDM symbol. Therefore, the receiver can set a gain that can effectively receive signals (eg, PSCCH/PSSCH or PSFCH) input from the second OFDM symbol by transmitting an arbitrary signal in the first OFDM symbol section. As in the first to third embodiments described above, a copy of the signal to be transmitted in the second OFDM symbol period may be used in the first OFDM symbol period. However, in the first to third embodiments described above, the AFC operation using the signal of the first OFDM symbol interval cannot be performed.

Meanwhile, as in the above-described fifth to seventh embodiments, as long as a signal with the same transmission power is transmitted in the first OFDM symbol interval even though it is not a copy of the signal to be transmitted in the second OFDM symbol interval, the gain determination unit 1222 The gain can be set to effectively receive the signal (eg, PSCCH/PSSCH or PSFCH) input from the second OFDM symbol using the signal level measured by the signal level detector 1221. That is, the receiver in the fifth to seventh embodiments described above can estimate the frequency difference occurring between the two terminals because it knows the signal transmitted in the first OFDM symbol, and performs an AFC operation to correct the estimated frequency difference. can be performed.

The frequency detection unit 1231 can detect the frequency difference using a signal converted from a time domain signal that has passed through the ADC unit 1214 into a frequency domain signal through the fast Fourier transform unit 1215. Additionally, the signal to be transmitted in the first OFDM symbol section can be set so that the frequency difference can be detected using the time domain signal that passed through the ADC unit 1214.

Therefore, if the sidelink transmits a signal that has the same transmission power in the symbol section for the terminal's AGC operation and includes signals previously shared between communication entities to help AFC operation, the receiver ensures smooth operation of AGC and AFC. can be achieved simultaneously. DMRS may be a signal used for channel estimation. DMRS can also be used to ensure smooth operation of AFC and AGC.

In particular, in the case of a transmitting terminal, if a DMRS signal is used as a signal containing a signal previously shared between communication entities in the symbol section (twelfth symbol) before the PSFCH symbol in the slot format of the seventh embodiment shown in FIG. 11, It can be used as a signal for channel estimation as well as AGC and AFC, making it possible to perform coherent demodulation on the PSFCH signal, which can contribute to improving the detection performance of the feedback signal. Therefore, the receiving terminal can use sequence-based feedback in the form of a “1” or “-1” signal used for uplink and downlink feedback signals. Alternatively, the receiving terminal may use sequence-based feedback in the form of “0” or “1” for uplink and downlink feedback signals.

Methods according to the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. Computer-readable media may include program instructions, data files, data structures, etc., singly or in combination. Program instructions recorded on a computer-readable medium may be specially designed and constructed for the present invention or may be known and usable by those skilled in the computer software art.

Examples of computer-readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The above-described hardware device may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

Although the description has been made with reference to the above examples, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will be able to.

Claims (20)

A method of operating a transmitting terminal that performs sidelink communication,
Transmitting a first shared signal with the receiving terminal to the receiving terminal;
Transmitting a first signal including sidelink control information (SCI) and sidelink data to the receiving terminal; and
Receiving a second signal including feedback on the sidelink data from the receiving terminal,
The first shared signal is a signal for the receiving terminal to correct the frequency difference occurring in the link between the transmitting terminal and the receiving terminal,
How the transmitting terminal operates. In claim 1,
The operating method of the transmitting terminal is,
Further comprising receiving a second shared signal with the receiving terminal from the receiving terminal,
The second shared signal is a signal for correcting the frequency difference,
How the sending terminal operates. In claim 1,
The first shared signal includes a demodulation reference signal (DMRS),
How the transmitting terminal operates. In claim 2,
The step of receiving the second shared signal from the receiving terminal,
measuring the magnitude of the second shared signal; and
Further comprising determining a reception gain based on the measured size,
The reception gain is a gain value to be reflected in the second signal,
How the transmitting terminal operates. In claim 2,
The operating method of the transmitting terminal is,
estimating the frequency difference based on the second shared signal; and
Further comprising correcting the frequency difference in the second signal based on the estimated frequency difference,
How the transmitting terminal operates. In claim 5,
The frequency difference is estimated based on either a time domain signal of the section in which the second shared signal is transmitted or a frequency domain signal obtained by Fourier transforming the second shared signal,
How the transmitting terminal operates. In claim 2,
The operating method of the transmitting terminal is,
Further comprising estimating a channel with the receiving terminal based on the DMRS included in the second shared signal,
How the transmitting terminal operates. A method of operating a receiving terminal performing sidelink communication,
Receiving a first shared signal with a transmitting terminal from the transmitting terminal;
Receiving a first signal including sidelink control information (SCI) and sidelink data from the transmitting terminal; and
It includes transmitting a second signal including feedback for the sidelink data to the transmitting terminal,
The first shared signal is a signal for the receiving terminal to correct the frequency difference occurring in the link between the transmitting terminal and the receiving terminal,
How the receiving terminal operates. In claim 8,
The operating method of the receiving terminal is,
Further comprising transmitting a second shared signal with the transmitting terminal to the transmitting terminal,
The second shared signal is a signal for correcting the frequency difference,
How the receiving terminal operates. In claim 8,
The step of receiving the first shared signal from the transmitting terminal,
measuring the magnitude of the first shared signal; and
Further comprising determining a reception gain based on the measured size,
The reception gain is a gain value to be reflected in the first signal,
How the receiving terminal operates. In claim 8,
The operating method of the receiving terminal is,
estimating the frequency difference based on the first shared signal; and
Further comprising correcting the frequency difference in the first signal based on the estimated frequency difference,
How the receiving terminal operates. In claim 11,
The frequency difference is estimated based on either a time domain signal of the section in which the first shared signal is transmitted or a frequency domain signal obtained by Fourier transforming the first shared signal,
How the receiving terminal operates. In claim 9,
The second shared signal includes a demodulation reference signal (DMRS),
How the receiving terminal operates. In claim 13,
The operating method of the receiving terminal is,
Further comprising the step of supplementing channel estimation with the transmitting terminal based on the DMRS included in the second shared signal,
How the receiving terminal operates. A receiving terminal that performs sidelink communication,
processor;
a memory that communicates electronically with the processor; and
Contains instructions stored in the memory,
When the instructions are executed by the processor, the instructions are executed by the receiving terminal,
receive a first shared signal with the transmitting terminal from the transmitting terminal;
Receive a first signal including sidelink control information (SCI) and sidelink data from the transmitting terminal; and
Operate to cause transmission of a second signal including feedback for the sidelink data to the transmitting terminal,
The first shared signal is a signal for the receiving terminal to correct the frequency difference occurring in the link between the transmitting terminal and the receiving terminal,
Receiving terminal. In claim 15,
Transmitting a second shared signal with the transmitting terminal to the transmitting terminal,
The second shared signal is a signal for correcting the frequency difference,
Receiving terminal. In claim 15,
When receiving the first shared signal from the transmitting terminal,
measure the magnitude of the first shared signal; and
determining a reception gain based on the measured magnitude,
The reception gain is a gain value to be reflected in the first signal,
Receiving terminal. In claim 15,
The commands allow the receiving terminal to
estimate the frequency difference based on the first shared signal; and
operative to cause correction of the frequency difference in the first signal based on the estimated frequency difference,
Receiving terminal. In claim 18,
The frequency difference is estimated based on either a time domain signal of the section in which the first shared signal is transmitted or a frequency domain signal obtained by Fourier transforming the first shared signal,
Receiving terminal. In claim 16,
The commands allow the receiving terminal to
Operates to cause supplementation of channel estimation with the transmitting terminal based on a demodulation reference signal (DMRS) included in the second shared signal,
Receiving terminal.

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