KR20230057978A - Apparatus and method for transmitting sidelink data in multiple antenna system - Google Patents

Abstract

Method for performing sidelink communication based on LoS MIMO

Description

Apparatus and method for transmitting sidelink data in a multi-antenna system {APPARATUS AND METHOD FOR TRANSMITTING SIDELINK DATA IN MULTIPLE ANTENNA SYSTEM}

The present invention relates to wireless communication, and more particularly, to an apparatus and method for transmitting sidelink data in a multi-antenna system.

BACKGROUND As the spread of smartphones and Internet of Things (IoT) terminals is rapidly spreading, the amount of information exchanged through a communication network is increasing. Accordingly, in the next-generation radio access technology, an environment that provides faster service to more users than the existing communication system (or existing radio access technology) (e.g., enhanced mobile broadband communication) )) needs to be considered. To this end, a communication system considering Machine Type Communication (MTC), which provides a service by connecting a plurality of devices and objects, is being developed. In addition, a communication system (e.g. URLLC (Ultra-Reliable and Low Latency Communication) that considers services and/or terminals that are sensitive to reliability and/or latency of communication is being developed. there is.

A method for performing sidelink communication based on Line of Sight MIMO (LoS MIMO) applicable in a next-generation wireless communication system is required.

The present specification proposes a method and apparatus for performing sidelink communication based on LoS MIMO applicable in a next-generation wireless communication system.

Specifically, according to an embodiment, in a method performed by a first terminal in a wireless communication system supporting line of sight (LoS) multiple input multiple output (MIMO), configuration information related to the LoS MIMO is received from a base station and performs sidelink communication with a second terminal based on the setting information based on the LoS MIMO, wherein the LoS MIMO is a MIMO in which transmission and reception of a plurality of layers based on line of sight is supported, and the sidelink communication is characterized in that it comprises LoS MIMO transmission for transmitting a plurality of transmission signals using a plurality of transmission antennas of a first terminal and LoS MIMO reception for receiving a plurality of reception signals using a plurality of reception antennas of the first terminal How to do it is suggested.

According to another embodiment, a first terminal in a wireless communication system supporting line of sight (LoS) multiple input multiple output (MIMO) includes one or more memories for storing instructions; one or more transceivers; and one or more processors connecting the one or more memories and the one or more transceivers, wherein the one or more processors execute the instructions to receive configuration information related to the LoS MIMO from a base station, and based on the configuration information to perform sidelink communication with a second terminal based on the LoS MIMO, wherein the LoS MIMO is a MIMO in which transmission and reception of a plurality of layers based on a line of sight is supported, and the sidelink communication is performed through a plurality of transmit antennas of the first terminal An apparatus including LoS MIMO transmission for transmitting a plurality of transmission signals using a plurality of transmission signals and LoS MIMO reception for receiving a plurality of reception signals using a plurality of reception antennas of the first terminal is proposed.

According to another embodiment, an apparatus configured to control a first terminal in a wireless communication system supporting Line of Sight (LoS) Multiple Input Multiple Output (MIMO), the apparatus comprising: one or more processors; and one or more memories executablely coupled by the one or more processors and storing instructions, wherein the one or more processors execute the instructions to receive configuration information related to the LoS MIMO from a base station, and Based on the setting information, sidelink communication is performed with a second terminal based on the LoS MIMO, wherein the LoS MIMO is MIMO in which transmission and reception of a plurality of layers based on line of sight is supported, and the sidelink communication is performed for the first terminal. An apparatus characterized by comprising LoS MIMO transmission for transmitting a plurality of transmission signals using a plurality of transmission antennas and LoS MIMO reception for receiving a plurality of reception signals using a plurality of reception antennas of the first terminal is proposed. do.

When performing MIMO-based communication, there is an effect of improving transmission speed of sidelink data by forming a plurality of layers even in a LoS environment.

1 is a conceptual diagram illustrating a wireless communication system according to an embodiment of the present invention.
2 is an exemplary diagram illustrating a 3GPP 5G system to which a data transmission method according to an embodiment of the present invention 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 (BWP) supported by a radio access technology to which this embodiment can be applied.
5 is a diagram exemplarily illustrating a synchronization signal block in a radio access technology to which this embodiment can be applied.
6 is a diagram for explaining the principle of a vertical-horizontal (VH) polarization antenna.
7 illustrates a LoS MIMO system used for microwave transmission according to an example.
8 is a flowchart illustrating a LoS MIMO configuration procedure for sidelink according to an example.
9 is a flowchart illustrating a LoS MIMO configuration procedure for sidelink according to another example.
10 is a flowchart illustrating a LoS MIMO configuration procedure for sidelink according to another example.
11 is a flowchart illustrating a LoS MIMO configuration procedure for sidelink according to another example.
12 is a flowchart illustrating a LoS MIMO control procedure for sidelink according to an example.
13 is a flowchart illustrating a LoS MIMO control procedure for sidelink according to another example.
14 is a flowchart illustrating a method of transmitting an SL Demodulation Reference Signal (DM-RS) according to an example.
15 is a flowchart illustrating a method of transmitting an SL CSI-RS (Channel State Information Reference Signal) according to an example.
16 shows a transmitting terminal and a receiving terminal in which an embodiment of the present invention is implemented.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals have been used for like elements throughout the description of each figure.

In this specification, terms such as "first", "second", "A", and "B" may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The term “and/or” also includes any combination of a plurality of related recited items or any one of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Terms used in this specification, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, unless otherwise defined. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this specification, they should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram illustrating a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 1, a wireless communication system 100 includes a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, and 130-3. , 130-4, 130-5, 130-6).

Each of the plurality of communication nodes may support at least one communication protocol. For example, each of the plurality of communication nodes is a communication protocol based on code division multiple access (CDMA), a communication protocol based on wideband CDMA (WCDMA), a communication protocol based on time division multiple access (TDMA), and a frequency division multiplex (FDMA) Access) based communication protocol, OFDM (Orthogonal Frequency Division Multiplexing) based communication protocol, OFDMA (Orthogonal Frequency Division Multiple Access) based communication protocol, SC (Single Carrier)-FDMA based communication protocol, NOMA (Non-Orthogonal Multiplexing) based communication protocol Access) based communication protocol, space division multiple access (SDMA) based communication protocol, etc. may be supported.

The wireless communication system 100 includes a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 and a plurality of user equipments 130-1, 130-2, 130-3, 130-4, 130-5, 130-6).

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. A fourth base station 120-1, a third terminal 130-3, and a fourth terminal 130-4 may belong to the coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the coverage of the third base station 110-3. . The first terminal 130-1 may belong within the coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong within the coverage of the fifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 is a NodeB, an evolved NodeB, and a next generation Node B. B, gNB), base transceiver station (BTS), radio base station, radio transceiver, access point, access node, roadside unit (RSU), Digital Unit (DU), Cloud Digital Unit (CDU), Radio Remote Head (RRH), Radio Unit (RU), Transmission Point (TP), Transmission and Reception Point (TRP), relay node, etc. can Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 is a terminal, an access terminal, a mobile terminal, It may be referred to as a station, subscriber station, mobile station, portable subscriber station, node, device, and the like.

A plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) Each may support cellular communication (eg, long term evolution (LTE), advanced (LTE-A), new radio (NR), etc. specified in the 3rd generation partnership project (3GPP) standard). Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other through ideal backhaul or non-ideal backhaul, and ideal backhaul Alternatively, information can be exchanged with each other through non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to a core network (not shown) through an ideal backhaul or a non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to a corresponding terminal 130-1, 130-2, 130-3, and 130 -4, 130-5, 130-6), and signals received from corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 are transmitted to the core network can be sent to

Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may support downlink transmission based on OFDM or another transmission method. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 supports uplink transmission based on OFDM or DFT-Spread-OFDM or another transmission method. can In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits MIMO (Multiple Input Multiple Output) (eg, SU (Single User)-MIMO, MU (Multi User)-MIMO, Massive MIMO, etc.), CoMP (Coordinated Multipoint) transmission, carrier aggregation transmission, transmission in unlicensed band, device to device direct (device to device, D2D) communication (or ProSe (proximity services)) may be supported. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 Operations corresponding to base stations 110-1, 110-2, 110-3, 120-1, and 120-2 and/or base stations 110-1, 110-2, 110-3, 120-1, and 120-2 ) can perform operations supported by

For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 based on SU-MIMO or LoS MIMO, and the fourth terminal 130-4 may transmit a signal based on SU-MIMO or LoS MIMO. Alternatively, the signal may be received from the second base station 110-2 by LoS MIMO. Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 based on the MU-MIMO scheme, and the fourth terminal 130-4 And each of the fifth terminal 130-5 may receive a signal from the second base station 110-2 by the MU-MIMO method. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, and The terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by CoMP. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 includes terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) and signals can be transmitted and received based on the CA method.

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 coordinates D2D communication between the fourth terminal 130-4 and the fifth terminal 130-5. (coordination), and each of the fourth terminal 130-4 and the fifth terminal 130-5 communicates D2D by the coordination of the second base station 110-2 and the third base station 110-3, respectively. can be performed.

Hereinafter, even when a method (eg, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a second communication node corresponding to the method performed in the first communication node corresponds to the method performed in the first communication node. A method (eg, receiving or transmitting a signal) may be performed. That is, when the operation of the terminal is described, the corresponding base station may perform an operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, a terminal corresponding thereto may perform an operation corresponding to the operation of the base station.

Also, below, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In downlink, a transmitter may be part of a base station and a receiver may be part of a terminal. In uplink, a transmitter may be a part of a terminal and a receiver may be a part of a base station.

Recently, as the spread of smart phones and Internet of Things (IoT) terminals is rapidly spreading, the amount of information exchanged through a communication network is increasing. Accordingly, in the next-generation radio access technology, an environment that provides faster service to more users than the existing communication system (or existing radio access technology) (e.g., enhanced mobile broadband communication) )) needs to be considered. To this end, a design of a communication system considering Machine Type Communication (MTC), which provides a service by connecting a plurality of devices and objects, is being discussed. In addition, the design of a communication system (e.g., URLLC (Ultra-Reliable and Low Latency Communication)) considering services and/or terminals that are sensitive to communication reliability and/or latency are being discussed

Hereinafter, for convenience of description, the next-generation radio access technology may be referred to as New RAT (Radio Access Technology) or may be referred to by other names. For example, a wireless communication system to which New RAT is applied may be referred to as a New Radio (NR) system. 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 next-generation wireless access technology It can be interpreted in various meanings used in the past or present or in the future.

2 is an exemplary diagram illustrating an NR system to which a data transmission method according to an embodiment of the present invention can be applied.

NR, a next-generation wireless communication technology under standardization in 3GPP, is a radio access technology that can provide improved data rates compared to LTE and satisfy various QoS requirements for each segmented and specified usage scenario. . In particular, eMBB (enhanced Mobile BroadBand), mMTC (massive MTC), and URLLC (Ultra Reliable and Low Latency Communications) have been defined as typical usage scenarios of NR. As a method for satisfying the requirements for each scenario, a frame structure that is flexible compared to LTE is provided. The frame structure of NR supports a frame structure based on multiple subcarriers. The default subcarrier spacing (SCS) is 15 kHz, and a total of 5 types of SCS are supported with 15 kHz * 2^n (n = 0, 1, 2, 3, 4).

Referring to FIG. 2, a Next Generation-Radio Access Network (NG-RAN) provides a control plane (RRC) protocol termination for an NG-RAN user plane (SDAP/PDCP/RLC/MAC/PHY) and a UE (User Equipment). It consists of gNBs that provide Here, NG-C represents a control plane interface used for an NG2 reference point between the NG-RAN and a 5 Generation Core (5GC). NG-U represents the user plane interface used for the NG3 reference point between NG-RAN and 5GC.

The gNBs are interconnected through the Xn interface and connected to the 5GC through the NG interface. More specifically, the gNB is connected to an Access and Mobility Management Function (AMF) through an NG-C interface and to a User Plane Function (UPF) through an NG-U interface.

In the NR system of FIG. 2, a number of numerologies may be supported. Here, the numerology may be defined by subcarrier spacing and CP (Cyclic Prefix) overhead. In this case, the multiple subcarrier spacing can be derived by scaling the basic subcarrier spacing by an integer. Also, although it is assumed that very low subcarrier spacing is not used at very high carrier frequencies, the numerology used can be selected independently of the frequency band.

Also, in the NR system, various frame structures according to a plurality of numerologies may be supported.

<NR wave form, numerology and frame structure>

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

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

Specifically, the NR transmission numerology is determined based on the sub-carrier spacing and CP (Cyclic prefix), and as shown in Table 1 below, the μ value is used as an exponential value of 2 based on 15 kHz, resulting in an exponential is changed to

μ subcarrier spacing
(kHz) 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 numerology of NR can be classified into five types according to the subcarrier spacing. This is different from the fact that the subcarrier interval of LTE, which is one of the 4G communication technologies, is fixed at 15 kHz. Specifically, in NR, subcarrier intervals used for data transmission are 15, 30, 60, and 120 kHz, and subcarrier intervals used for synchronization signal transmission are 15, 30, 120, and 240 kHz. In addition, the extended CP is applied only to a 60 kHz subcarrier interval. Meanwhile, a frame structure in NR is defined as a frame having a length of 10 ms composed of 10 subframes having the same length of 1 ms. One frame may 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.

<NR Physical Resource>

Regarding physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, bandwidth parts, etc. are considered do.

An antenna port is defined such that the channel on which a symbol on an antenna port is carried can be inferred from the channel on which other symbols on the same antenna port are carried. Two antenna ports are quasi co-located or QC/QCL (quasi co-located or quasi co-location). Here, the wide range characteristics include one or more of delay spread, Doppler spread, Doppler shift, average delay, and spatial Rx parameter.

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 , since NR supports a plurality of numerologies in the same carrier, a resource grid may exist according to each numerology. Also, resource grids may exist according to antenna ports, subcarrier intervals, and transmission directions.

A resource block consists of 12 subcarriers and is defined only in the frequency domain. Also, a resource element is composed of one OFDM symbol and one subcarrier. Accordingly, as shown in FIG. 3, the size of one resource block may vary according to the subcarrier interval. In addition, in NR, “Point A”, which serves as a common reference point for the resource block grid, and common resource blocks and physical resource blocks are defined.

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

In 5G NR, unlike LTE E-UTRA where the carrier bandwidth is fixed at 20 MHz, the maximum carrier bandwidth is set from 50 MHz to 400 MHz 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) can be designated and used by a UE within a carrier bandwidth. In addition, the bandwidth part is associated with one numerology, is composed of a subset of consecutive common resource blocks, and can be dynamically activated according to time. Up to four bandwidth parts each of uplink and downlink are configured in the terminal, and data is transmitted and received using the active bandwidth part at a given time.

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

<NR initial connection>

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

Cell search is a procedure in which a UE synchronizes with a cell of a corresponding base station using a synchronization signal block (SSB) transmitted by the base station, acquires 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 this 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, 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 5 ms. A plurality of SSBs are transmitted in different transmission beams within 5 ms, and the UE performs detection assuming that SSBs are transmitted every 20 ms period based on one specific beam used for transmission. The number of beams usable for SSB transmission within 5ms may increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted below 3 GHz, SSBs 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 higher.

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, SSB is not transmitted at the center frequency of the carrier bandwidth, unlike SS of conventional LTE. That is, the SSB can be transmitted even in a place other than the center of the system band, and a plurality of SSBs can 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 it can support fast SSB search of the terminal. can

The UE may acquire the MIB through the PBCH of the SSB. MIB (Master Information Block) includes minimum information for the terminal to receive the remaining minimum system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, the PBCH includes information about the position of the first DM-RS symbol in the time domain, information for monitoring SIB1 by the UE (eg, SIB1 numerology 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 location of the absolute SSB within the carrier is transmitted through SIB1), and the like. Here, the SIB1 numerology information is equally applied to some messages used in the random access procedure for accessing the base station after the UE completes the cell search procedure. For example, the numerical information of SIB1 may be applied to at least one of messages 1 to 4 for a random access procedure.

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

<side link>

NR, a Radio Access Technology (RAT) of the 5G mobile communication system, supports sidelink (SL) for D2D.

The sidelink is an interface between terminals for sidelink communication and sidelink discovery. The sidelink corresponds to the PC5 interface. Sidelink communication is a function that allows two or more adjacent terminals to communicate directly using ProSe (proximity-based services) using E-UTRA (or NR in 5G) technology without going through any network node. This is a function that enables a nearby terminal to directly discover ProSe using E-UTRA (or NR) technology without going through any network node. Hereinafter, in sidelink communication, a terminal transmitting a signal is referred to as a transmitting terminal (Tx UE), and a terminal receiving a signal is referred to as a receiving terminal (Rx UE).

A sidelink physical channel is formed between sidelink terminals, and includes a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSCH), a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), and a physical sidelink channel (PSFCH). feedback channels). PSBCH carries system and synchronization related information, PSDCH carries sidelink discovery message, PSCCH carries control information for sidelink communication, PSSCH carries data for sidelink communication, and PSFCH carries receiving terminal transmits H-ARQ feedback to the transmitting terminal. Sidelink physical channels are mapped to sidelink transport channels. PSBCH is mapped to a sidelink broadcast channel (SL-BCH). PSDCH is mapped to a sidelink discovery channel (SL-DCH). PSSCH is mapped to a sidelink shared channel (SL-SCH).

Even in the sidelink, logical channels are classified into a control channel for information transfer in the control plane and a traffic channel for information transfer in the user plane. The sidelink control channel includes a sidelink broadcast control channel (SBCCH), which is a sidelink channel for broadcasting sidelink system information from one terminal to another terminal. SBCCH is mapped to SL-BCH. The sidelink traffic channel includes a sidelink traffic channel (STCH), which is a point-to-multipoint channel for transmitting user information from one terminal to another terminal. STCH is mapped to SL-SCH. This channel can be used only by terminals capable of sidelink communication.

A terminal supporting sidelink communication may operate in the following two modes for resource allocation. The first mode is a scheduled resource allocation mode. Scheduled resource allocation may be referred to as Mode 1. In mode 1, the terminal needs to be in RRC_CONNECTED to transmit data. The terminal requests transmission resources from the base station. The base station schedules transmission resources for transmission of sidelink control information (SCI) and data. The terminal transmits a scheduling request (dedicated scheduling request (D-SR) or random access) to the base station and then sends a sidelink buffer status report (BSR). Based on the sidelink BSR, the base station can determine that the terminal has data for sidelink communication transmission, and can estimate resources required for transmission. The base station may schedule transmission resources for sidelink communication using the configured sidelink radio network temporary identity (SL-RNTI).

The second mode is UE autonomous resource selection. The UE autonomous resource selection mode may be referred to as mode 2. In mode 2, the terminal itself selects a resource from the resource pool and selects a transmission format for transmitting sidelink control information and data. There may be up to 8 resource pools pre-configured for out-of-coverage operation or provided by RRC signaling for in-coverage operation. One or more ProSe per-packet priority (PPPP) may be connected to each resource pool. For transmission of a MAC protocol data unit (PDU), the terminal selects a resource pool having one of the same PPPPs as the PPPP of the logical channel having the highest PPPP among the logical channels identified in the MAC PDU. The sidelink control pool and the sidelink data pool are associated one-to-one. When a resource pool is selected, the selection is valid for the entire sidelink control period. After the sidelink control period ends, the UE may select a resource pool again.

On the other hand, there are two types of resource allocation in discovery message notification. The first is UE autonomous resource selection, which is a resource allocation procedure in which resources for announcing discovery messages are allocated on a non-UE specific basis. UE autonomous resource selection may be referred to as Type 1. In type 1, the base station provides the terminal with a resource pool configuration used for notification of discovery messages. The corresponding configuration may be signaled through broadcasting or dedicated signaling. The terminal autonomously selects a radio resource from the indicated resource pool and announces a discovery message. The terminal may announce a discovery message on a randomly selected discovery resource during each discovery period.

The second is scheduled resource allocation, which is a resource allocation procedure in which resources for notifying discovery messages are allocated on a UE-specific basis. Scheduled resource allocation may be referred to as type 2. In type 2, an RRC_CONNECTED terminal may request a resource for notifying a discovery message to a base station through RRC. The base station allocates resources through RRC. Resources are allocated within a resource pool configured within the terminal for notification.

Hereinafter, sidelink communication through ProSe UE-network relay will be described. ProSe UE-network relay provides general L3 forwarding function to relay all types of IP traffic between remote terminal and network. One-to-one and one-to-many sidelink communication is used between the remote terminal and the relay terminal. For both the remote UE and the relay UE, only one single carrier (ie public safety ProSe carrier) operation is supported (ie Uu and PC5 must be the same carrier for the relay/remote UE). The remote terminal has been authenticated by higher layers and may be in coverage of a public safety ProSe carrier or out of coverage of all supported carriers, including public safety ProSe carriers, for UE-network relay discovery, (re)selection and communication. A relay terminal is always within range of EUTRAN (or NG-RAN in case of 5G). The relay terminal and the remote terminal perform sidelink communication and sidelink discovery.

The base station controls whether the terminal can act as a ProSe UE-network relay. If the base station broadcasts information related to the ProSe UE-network relay operation, the ProSe UE-network relay operation is supported in the cell. The base station may provide transmission resources for ProSe UE-network relay discovery using broadcast signaling for RRC_IDLE and dedicated signaling for RRC_CONNECTED, and reception resources for ProSe UE-network relay discovery using broadcast signaling. In addition, the base station may broadcast minimum and/or maximum Uu link quality (ie, reference signal received power (RSRP)) threshold values that need to be satisfied before the UE initiates the ProSe UE-network relay discovery procedure. In RRC_IDLE, when the base station broadcasts the transmission resource pool, the terminal uses the threshold to autonomously start or stop the ProSe UE-network relay discovery procedure. In RRC_CONNECTED, the UE uses the threshold to determine whether it can indicate to the eNB that it is a relay UE and wants to initiate ProSe UE-network relay discovery. If the base station does not broadcast the transmission resource pool for ProSe UE-network relay discovery, the terminal may initiate a request for ProSe UE-network relay discovery resources by dedicated signaling while considering the broadcasted threshold value. If ProSe UE-network relay is initiated by broadcast signaling, the relay terminal may perform ProSe UE-network relay discovery in RRC_IDLE. If ProSe UE-network relay is initiated by dedicated signaling, the relay terminal may perform ProSe UE-network relay discovery as long as it is in RRC_CONNECTED.

A relay terminal performing sidelink communication for ProSe UE-network relay operation must be in RRC_CONNECTED. After receiving a layer 2 link establishment request or a temporary mobile group identity (TMGI) monitoring request (higher layer message) from a remote terminal, the relay UE indicates that it is a relay UE and wants to perform ProSe UE-network relay sidelink communication. inform The base station may provide resources for ProSe UE-network relay communication.

The remote terminal can decide when to start monitoring for ProSe UE-network relay discovery. The remote terminal may transmit a ProSe UE--network relay discovery inducement message while in the RRC_IDLE or RRC_CONNECTED state according to the configuration of resources for ProSe UE-network relay discovery. The base station may broadcast a threshold value used by the remote terminal to determine whether the remote terminal can transmit a ProSe UE-network relay discovery inducement message to connect or communicate with the relay terminal. A remote terminal in the RRC_CONNECTED state uses the broadcasted threshold to determine whether it can indicate that it is a remote terminal and wants to participate in ProSe UE-network relay discovery and/or communication. For the ProSe UE-network relay operation, the base station may provide transmission resources using broadcast or dedicated signaling, or may provide reception resources using broadcast signaling. If the RSRP exceeds the broadcasted threshold, the remote terminal stops using the ProSe UE-network relay discovery search and communication resources. The exact time to switch traffic from Uu to PC5 (sidelink) and vice versa is up to the upper layers.

The remote terminal performs radio measurement on the PC5 interface and uses it for relay terminal selection and reselection along with higher layer criteria. If the PC5 link quality exceeds the configured threshold (either pre-configured or provided by the eNB), the relay terminal is considered to be suitable with respect to radio criteria. The remote terminal selects a relay terminal that satisfies the upper layer criteria and has the best PC5 link quality among all suitable relay terminals.

The remote terminal triggers relay terminal reselection when the PC5 signal strength of the current relay terminal is lower than the configured signal strength threshold or when receiving a layer 2 link release message (higher layer message) from the relay terminal.

<6G system>

A next-generation communication system after 5G or 5G-Advanced is described. Hereinafter, for convenience, the next-generation communication system is referred to as a 6G system.

6G (radio communications) systems are characterized by (i) very high data rates per device, (ii) very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) battery- It aims to lower energy consumption of battery-free IoT devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be in four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity. Although the requirements or key performance indicators (KPIs) for the 6G system have not yet been determined, the table below It is expected to have the same requirements as 2. That is, Table 2 is a table showing an example of requirements for a 6G system.

peak data rate 1 Tbps E2E latency 1ms Maximum spectral efficiency 100 bps/Hz Mobility support Up to 1000km/hr Satellite integration Fully AI Fully Autonomous vehicles Fully XR Fully Haptic Communication Fully

6G systems include Enhanced mobile broadband (eMBB), Ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), AI integrated communication, Tactile internet, High throughput, High network capacity, High energy efficiency, Low backhaul and It can have key factors such as access network congestion and enhanced data security.

Hereinafter, artificial intelligence (AI) is explained.

The most important and newly introduced technology for the 6G system is AI. AI was not involved in the 4G system. 5G systems will support partial or very limited AI. However, the 6G system will be AI-enabled for full automation. Advances in machine learning will create more intelligent networks for real-time communication in 6G. Introducing AI in communications can simplify and enhance real-time data transmission. AI can use a plethora of analytics to determine how complex target tasks are performed. In other words, AI can increase efficiency and reduce processing delays.

Time-consuming tasks such as handover, network selection, and resource scheduling can be performed instantly by using AI. AI can also play an important role in machine-to-machine, machine-to-human and human-to-machine communications. In addition, AI can be a rapid communication in BCI (Brain Computer Interface). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

Recently, there have been attempts to integrate AI with wireless communication systems, but these have been focused on the application layer and network layer, especially deep learning in the field of wireless resource management and allocation. However, these studies are gradually developing into the MAC layer and the physical layer, and in particular, attempts to combine deep learning with wireless transmission are appearing in the physical layer. AI-based physical layer transmission means applying a signal processing and communication mechanism based on an AI driver rather than a traditional communication framework in fundamental signal processing and communication mechanisms. For example, deep learning-based channel coding and decoding, deep learning-based signal estimation and detection, deep learning-based MIMO mechanism, AI-based resource scheduling and may include allocations, etc.

Machine learning may be used for channel estimation and channel tracking, and may be used for power allocation, interference cancellation, and the like in a downlink (DL) physical layer. Machine learning can also be used for antenna selection, power control, symbol detection, and the like in a MIMO system.

However, the application of DNN for transmission in the physical layer may have the following problems.

AI algorithms based on deep learning require a lot of training data to optimize training parameters. However, due to limitations in acquiring data in a specific channel environment as training data, a lot of training data is used offline. This is because static training on training data in a specific channel environment may cause a contradiction between dynamic characteristics and diversity of a radio channel.

In addition, current deep learning mainly targets real signals. However, the signals of the physical layer of wireless communication are complex signals. In order to match the characteristics of wireless communication signals, further research on a neural network for detecting complex domain signals is needed.

Hereinafter, machine learning will be described in more detail.

Machine learning refers to a set of actions that train a machine to create a machine that can do tasks that humans can or cannot do. Machine learning requires data and a running model. In machine learning, data learning methods can be largely classified into three types: supervised learning, unsupervised learning, and reinforcement learning.

Neural network training is aimed at minimizing errors in the output. Neural network learning repeatedly inputs training data to the neural network, calculates the output of the neural network for the training data and the error of the target, and backpropagates the error of the neural network from the output layer of the neural network to the input layer in a direction to reduce the error. ) to update the weight of each node in the neural network.

Supervised learning uses training data in which correct answers are labeled in the learning data, and unsupervised learning may not have correct answers labeled in the learning data. That is, for example, learning data in the case of supervised learning related to data classification may be data in which each learning data is labeled with a category. Labeled training data is input to the neural network, and an error may be calculated by comparing the output (category) of the neural network and the label of the training data. The calculated error is back-propagated in a reverse direction (ie, from the output layer to the input layer) in the neural network, and the connection weight of each node of each layer of the neural network may be updated according to the back-propagation. The amount of change in the connection weight of each updated node may be determined according to a learning rate. The neural network's computation of input data and backpropagation of errors can constitute a learning cycle (epoch). The learning rate may be applied differently according to the number of iterations of the learning cycle of the neural network. For example, a high learning rate is used in the early stages of neural network learning to increase efficiency by allowing the neural network to quickly achieve a certain level of performance, and a low learning rate can be used in the late stage to increase accuracy.

The learning method may vary depending on the characteristics of the data. For example, in a case where the purpose of the receiver is to accurately predict data transmitted by the transmitter in a communication system, it is preferable to perform learning using supervised learning rather than unsupervised learning or reinforcement learning.

The learning model corresponds to the human brain, and the most basic linear model can be considered. ) is called

The neural network cord used as a learning method is largely divided into deep neural networks (DNN), convolutional deep neural networks (CNN), and recurrent Boltzmann Machine (RNN). there is.

An artificial neural network is an example of connecting several perceptrons.

Hereinafter, THz (Tera-Hertz) communication is described.

The data rate can be increased by increasing the channel bandwidth. In order to easily secure a wide channel bandwidth, since a high frequency band must be used, a communication method using a sub-THz band, which is a frequency band higher than 100 GHz, and a higher THz band is being considered. In a communication method using a high frequency band, since the antenna size and the distance between the antennas are reduced, advanced massive MIMO technology can be applied. THz waves, also known as submillimeter radiation, typically represent a frequency band between 0.1 THz and 10 THz with corresponding wavelengths in the range of 0.03 mm-3 mm. The 100 GHz-300 GHz band range (sub-THz band) is considered a major part of the THz band for cellular communications. In 5G mobile communication, a frequency band of up to 100 GHz was considered, and the Sub-THz band and THz band are expected to be used in 6G mobile communication.

6G mobile communication uses Sub-THz and THz bands in addition to the existing mmWave band. When sub-THz band is added to mmWave band, it is easy to increase channel bandwidth because much more frequency resources are used, and as a result, data transmission rate and cell throughput increase. Among the defined THz bands, 300 GHz-3 THz is in the far infrared (IR) frequency band. The 300 GHz-3 THz band is part of the optical band, but is at the edge of the optical band, just behind the RF band. Thus, this 300GHz-3THz band exhibits similarities to RF.

The main characteristics of THz communication include (i) a fairly wide channel bandwidth widely available to support very high data rates, and (ii) high path loss at high frequencies (a highly directional antenna is indispensable). Since the wavelength is small, the size of the antenna is small and the distance between the antennas is very small, so a large number of antennas can be disposed in a small area. A narrow beam generated by applying beamforming to many antennas can reduce interference. That is, the small wavelength of the THz signal allows a much larger number of antenna elements to be incorporated into devices and BSs operating in this band. This enables advanced adaptive array technology to overcome range limitations.

THz wireless communication uses wireless communication using THz waves having a frequency of approximately 0.1 to 10 THz (1 THz = 1000 GHz), and may mean terahertz (THz) band wireless communication using a very high carrier frequency of 100 GHz or more. . THz waves are located between RF (Radio Frequency)/millimeter (mm) and infrared bands, and (i) transmit non-metal/non-polarizable materials better than visible light/infrared rays, and have a shorter wavelength than RF/millimeter waves and have high straightness. Beam focusing may be possible. In addition, since the photon energy of the THz wave is only a few meV, it is harmless to the human body. A frequency band expected to be used for THz wireless communication may be a D-band (110 GHz to 170 GHz) or H-band (220 GHz to 325 GHz) band with low propagation loss due to molecular absorption in the air. Standardization discussions on THz wireless communication are being discussed centering on the IEEE 802.15 THz working group in addition to 3GPP, and standard documents issued by the IEEE 802.15 Task Group (TG3d, TG3e) can specify or supplement the content described in this specification. there is. THz wireless communication may be applied to wireless cognition, sensing, imaging, wireless communication, THz navigation, and the like.

THz wireless communication scenarios can be classified into macro networks, micro networks, and nanoscale networks. In a macro network, THz wireless communication can be applied to V2V (Vehicle-to-Vehicle) communication and backhaul/fronthaul connection. In micro networks, THz wireless communication is applied to indoor small cells, fixed point-to-point or multi-point connections such as wireless connections in data centers, and near-field communication such as kiosk downloading. It can be.

<LoS (line of sight) MIMO system>

A MIMO system uses multiple transmit antennas and multiple receive antennas to support spatial multiplexing (SM). When the channel matrix between the transmitter and the receiver is H, elements of H are composed of channel gain values between the transmitter and the receiver. The number of spatially separable layers between the transmitter and the receiver is equal to the rank of the channel matrix, and a transmitter supporting SM can transmit different data to the receiver through a plurality of layers. Theoretically, the maximum speed or throughput of a MIMO system can increase in proportion to the number of ranks. When the number of ranks provided by H is denoted by rank(H), the maximum value of rank(H) is min(N _T , N _R ). Here, N _T is the number of transmit antennas, N _R is the number of receive antennas, and min(A, B) means the minimum values of A and B.

A state in which a signal transmitted from a transmitting antenna can be transferred to a receiving antenna in a straight line without any obstacle in the middle is called a Line of Sight (LoS) environment. In general, since signals transmitted from a plurality of transmit antennas reach the receive antenna through various paths reflected by obstacles, the rank of the channel matrix may be greater than 1 and a plurality of spatially separable layers may exist. However, SM cannot be applied in a LoS environment (particularly when the transmit and receive antennas are relatively close) because the rank of the channel matrix becomes almost 1 even if there are several transmit and receive antennas. This is because correlation between channel gain values, each element of the channel matrix H, increases.

To apply SM in such a LoS environment, it is necessary to improve the physical structure of an antenna or create multiple layers transmitted from a transmitter to a receiver by using various characteristics such as signal polarization. As an example, a method using a V-H (Vertical-Horizontal) polarization (V-H polarization) or X-polarization (X-polarization or Cross Polarization) antenna configures two physically separable layers to achieve transmission speed like SM even in a LoS environment. can be doubled. In addition, two or more layers can be created even in a LoS environment by applying two or more different types of LoS MIMIO at once.

6 is a diagram for explaining the principle of a V-H polarized antenna.

Referring to FIG. 6, the V-H polarized antenna includes a vertical antenna and a horizontal antenna that are 90 degrees apart from each other so that signals from each antenna can be physically distinguished. Alternatively, cross polarization (or X-polarization) antennas may use two crossed antennas forming +45 degrees and -45 degrees. The first signal transmitted from the vertical antenna of the transmitter may be received by the vertical antenna of the receiver as in (a), but is not received well as in (b) by the horizontal antenna of the receiver. Conversely, the second signal transmitted from the horizontal antenna of the transmitter can be well received by the horizontal antenna of the receiver as in (a), but is not well received by the vertical antenna of the receiver as in (b).

This is because the channel can be divided into two (ie, two layers are formed) between the transmit antenna and the receive antenna based on the V-H polarized antenna. In this case, since different signals (or data) can be transmitted through each channel, the rank becomes 2, so that two layers are formed. Hereinafter, in the present specification, a MIMO system capable of supporting two or more ranks in a LoS environment or during LoS communication is simply referred to as a LoS MIMO system. LoS environment can be used as equivalent to various terms such as LoS condition, LoS communication environment, and LoS state.

In this specification, the LoS MIMO system may be equipped with a V-H polarization or X polarization (cross-pol.) antenna to support a plurality of ranks even in a LoS environment. However, a LoS MIMO system may include any physical antenna structure capable of providing a plurality of ranks in a LoS environment, and is not necessarily limited to having a V-H polarized or X polarized antenna. For example, the LoS MIMO system is a linear polarization antenna (Vertical-Horizontal, Cross Polarization (X-pole, ±45 degrees)), a circular polarization antenna (left-circular, right-circular), and an elliptical polarization antenna (Elliptical Polarization). Any one or a combination of at least one of these may be used.

In a LoS environment, if the conventional MIMO and SM are used, the rank becomes 1 and SM cannot be applied. However, if the LoS MIMO system is used, the rank becomes 2 or higher and the data transmission rate can be increased.

In addition, when the number of antennas is large, a combination of LoS MIMO and beamforming may be possible. For example, if V-H polarization LoS MIMO and beamforming are combined, a beam can be formed with multiple antennas in the vertical direction, and a beam can be formed with multiple antennas in the horizontal direction to create two layers with two beams. there is.

7 illustrates a LoS MIMO system used for microwave transmission according to an example.

Referring to FIG. 7 , (a) shows polarization multiplexing supporting twice the capacity (2x), and (b) shows an NxN LoS MIMO system supporting N times capacity (Nx). Unlike the microwave transmission system, the mobile communication system has a wide antenna beam. Therefore, in a mobile communication system, NxN LoS MIMO in (b) can be considered in a special case. On the other hand, since the polarization multiplexing of (a) can be used in a high-frequency LoS environment, it can also be considered for a mobile communication system.

The LoS MIMO system can be applied to all frequency bands used in general mobile communication. In particular, the LoS MIMO system is very important in a high frequency band (eg, 10 GHz to 100 GHz, or hundreds of GHz or Tera-Hz (THz)). This is because the coverage is small in such a high frequency band, and there is a high possibility that a LoS environment is formed between the transmit antenna and the receive antenna. That is, in a high-frequency band, the transmission distance is relatively short, and communication is likely to occur more in a LoS environment that is directly visible than a reflected wave.

In addition, many LoS environments may occur when signals are transmitted and received in the air, such as in a Non-Terrestrial Network (NTN) environment using unmanned aerial vehicles or satellites.

Scenarios in which the LoS MIMO system is applied to high-frequency sidelink communication are as follows.

i) LoS environment where the transmitting terminal and the receiving terminal are relatively close: In this case, LoS MIMO performance may differ depending on the frequency and channel environment.

ii) Direct communication between servers in a data center, direct communication between cars, V2V in a platooning situation, communication between drones in the air, and communication between personal aerial vehicles (PAVs) or uncrewed aerial vehicles (UAVs) in the air etc.

iii) LoS environment between public base station and terminal

The 5G mobile communication system considers up to 100 GHz, and the 6G mobile communication system basically expects to add a band of 100 to 300 GHz, and the THz band may also be considered. In the 100 to 300 GHz band or higher frequencies considered in the 6G mobile communication system, the distance between the transmitter and the receiver is very short and a transmission speed of tens to hundreds of Gbps is required. In order to support such a transmission rate, a next-generation mobile communication system basically uses multiple antennas for a receiver as well as a transmitter. As the next-generation telecommunication communication system uses a high-frequency band, the frequency of communication in a LoS environment may increase. In this case, there is a high possibility that the rank converges to 1 and the existing SM is not supported.

Therefore, the next-generation telecommunication system adopts the LoS MIMO system, but it is highly likely to use a protocol different from the protocol that supported the existing SM. Therefore, a new protocol is required to introduce the LoS MIMO system into the standard technologies of 3GPP's 5G, 6G, and later generations.

In this specification, a sidelink terminal according to the LoS MIMO system can operate in a LoS MIMO mode supporting SM in a LoS environment and an existing MIMO mode that cannot support SM in a LoS environment. In this case, a procedure for setting or activating the LoS MIMO mode is required, and a related embodiment will be described below.

1. Transmission procedure of system information

8 is a flowchart illustrating a LoS MIMO configuration procedure for sidelink according to an example. 8 is an embodiment in which a transmitting terminal transmits system information to a receiving terminal.

Referring to FIG. 8 , the transmitting terminal may determine whether to support the LoS MIMO mode (S800). Step S800 may be omitted in some cases. The transmitting terminal transmits system information including LoS MIMO-related configuration information to the receiving terminal (S810).

As an example, the system information including the LoS MIMO-related configuration information may be a system information block (SIB).

As another example, the system information including the LoS MIMO-related configuration information may be a master information block (MIB).

If, in step S800, the transmitting terminal determines not to support the LoS MIMO operation, the system information may not include LoS MIMO-related setting information.

In step S810, LoS MIMO-related setting information included in the system information is basic setting information for LoS MIMO, and detailed setting information for LoS MIMO may be included in an RRC message transmitted by the base station. For example, if the setting information related to LoS MIMO includes A and B, A is basic setting information for LoS MIMO and transmitted to the receiving terminal in the system information of the transmitting terminal, and B is detailed setting information for LoS MIMO. After the RRC connection, RRC signaling of the base station may be carried and transmitted to the receiving terminal.

If the transmitting terminal supports a plurality of frequency bands, the transmitting terminal may vary whether to support LoS MIMO or support method for each frequency band. In this case, the transmitting terminal may include information about this in system information and transmit it. For example, assume that a transmitting terminal supports a first frequency band and a second frequency band. The transmitting terminal may identify that LoS MIMO is supported for the first frequency band and identify that LoS MIMO is not supported for the second frequency band in the system information. Alternatively, the transmitting terminal may identify LoS MIMO supported for the first frequency band and a LoS MIMO support method in the system information, and identify that LoS MIMO is not supported for the second frequency band.

After receiving the system information, the receiving terminal identifies LoS MIMO-related configuration information (S820). If the LoS MIMO-related setting information indicates LoS MIMO support, the receiving terminal transmits and receives a sidelink signal with the transmitting terminal based on LoS MIMO (S830). For example, step S830 includes generating a sidelink signal for each layer defined by LoS MIMO by the transmitting terminal, and transmitting the sidelink signal to the receiving terminal through a corresponding layer. The receiving terminal sets its receiving antenna to the LoS MIMO mode, and receives and decodes sidelink signals for each layer.

9 is a flowchart illustrating a LoS MIMO configuration procedure for sidelink according to another example. 9 is an embodiment in which a base station transmits system information to each terminal.

Referring to FIG. 9, the base station may determine whether to support the LoS MIMO mode (S900). Step S900 may be omitted in some cases. The base station transmits system information including LoS MIMO-related setting information to the transmitting terminal and the receiving terminal (S910).

As an example, the system information including the LoS MIMO-related setting information may be a system information block (SIB).

As another example, the system information including the LoS MIMO-related configuration information may be a master information block (MIB).

If, in step S900, the base station determines not to support the LoS MIMO operation, the system information may not include LoS MIMO-related configuration information.

In step S910, LoS MIMO-related setting information included in the system information is basic setting information for LoS MIMO, and detailed setting information for LoS MIMO may be included in an RRC message transmitted by the base station. For example, if LoS MIMO-related setting information includes A and B, A is basic setting information for LoS MIMO and transmitted to each terminal in the system information of the base station, and B is detailed setting information for LoS MIMO and RRC After connection, RRC signaling of the base station may be carried and transmitted to each terminal.

If SideLink (SL) between terminals supports a plurality of frequency bands, the base station may vary whether to support LoS MIMO or support method for each frequency band. In this case, the base station may include information about this in system information and transmit it. For example, assume that the terminal supports the first frequency band and the second frequency band. The base station may identify that LoS MIMO is supported for the first frequency band and identify that LoS MIMO is not supported for the second frequency band in the system information. Alternatively, the base station may identify, in system information, that LoS MIMO is supported for the first frequency band and a LoS MIMO support method, and identify that LoS MIMO is not supported for the second frequency band.

After receiving system information, each terminal identifies LoS MIMO-related setting information (S920). If LoS MIMO-related configuration information indicates LoS MIMO support, the transmitting terminal and the receiving terminal transmit and receive sidelink signals based on LoS MIMO (S930). For example, step S940 includes generating a sidelink signal for each layer defined by LoS MIMO by the transmitting terminal, and transmitting the sidelink signal to the receiving terminal through a corresponding layer. The receiving terminal sets its receiving antenna to the LoS MIMO mode, and receives and decodes sidelink signals for each layer.

2. LoS MIMO setting procedure at RRC (radio resource control) layer

10 is a flowchart illustrating a LoS MIMO configuration procedure for sidelink according to another example. 10 is an embodiment in which a base station transmits an RRC message to a transmitting terminal and a receiving terminal.

Referring to FIG. 10 , a transmitting terminal and a receiving terminal may transmit capability information indicating whether to support LoS MIMO to a base station (S1000). A procedure for checking information about whether LoS MIMO is available between the base station and the terminal and which LoS MIMO can be supported when there are various LoS MIMO options is required. The capability information may indicate which of various LoS MIMO schemes the transmitting terminal and the receiving terminal will support. Here, various LoS MIMO schemes are linear polarization antenna (Vertical-Horizontal, Cross Polarization (X-pole, ±45 degrees)), circular polarization antenna (left-circular, right-circular), elliptical polarization antenna (Elliptical Polarization), or In addition, one or more of the more complex methods may be included. For example, the capability information may indicate that LoS MIMO based on vertical-horizontal polarization is supported. If vertical-horizontal polarization and X-polarization are distinguished, the terminal can support up to 4 layers with LoS MIMO. In this case, the capability information may indicate that both vertical-horizontal polarization and X-polarization are supported.

The base station may determine whether to support the LoS MIMO mode for the transmitting terminal and the receiving terminal (S1010). Step S1010 may be omitted in some cases. The base station generates an RRC message including LoS MIMO-related configuration information and transmits it to the transmitting terminal and the receiving terminal (S1020).

If, in step S1010, the base station determines not to support the LoS MIMO operation, the RRC message may not include LoS MIMO-related configuration information.

As an example, the LoS MIMO-related setting information included in the RRC message in step S1020 may be setting information for LoS MIMO.

As another example, the LoS MIMO-related setting information included in the RRC message in step S1020 is detailed setting information for LoS MIMO, and basic setting information for LoS MIMO may be transmitted in advance through system information. For example, if LoS MIMO-related setting information is A and B, A is basic setting information for LoS MIMO and is transmitted in system information, and B is detailed setting information for LoS MIMO and is transmitted in RRC signaling after RRC connection. It can be.

If the terminal supports a plurality of frequency bands, the base station may vary whether to support LoS MIMO or support method for each frequency band. In this case, the base station may include information about this in an RRC message and transmit it. For example, assume that the terminal supports the first frequency band and the second frequency band. The base station may identify that LoS MIMO is supported for the first frequency band and that LoS MIMO is not supported for the second frequency band in the RRC message. Alternatively, the base station may identify that LoS MIMO is supported for the first frequency band and a LoS MIMO support method in the RRC message, and that LoS MIMO is not supported for the second frequency band.

After receiving the RRC message from the base station, the transmitting terminal and the receiving terminal identify LoS MIMO-related configuration information (S1030). If the LoS MIMO-related configuration information indicates LoS MIMO support, the transmitting terminal and the receiving terminal may transmit and receive signals based on LoS MIMO (S1040). Here, the signals transmitted and received in step S1040 include sidelink reference signals such as SL CSI-RS and SL DM-RS, and sidelink physical channels such as PSBCH, PSDCH, PSCCH (physical sidelink, PSSCH, PSFCH).

The base station can know whether the transmitting terminal and the receiving terminal have the capability to support LoS MIMO based on the capability information of the transmitting terminal and the receiving terminal. However, the transmitting terminal and the receiving terminal cannot know whether the other party supports LoS MIMO. In this case, a protocol for recognizing whether LoS MIMO is supported is required between the transmitting terminal and the receiving terminal.

As an example, the LoS MIMO-related setting information transmitted from the base station to the transmitting terminal in step S1020 may further include information on whether the receiving terminal supports LoS MIMO. In addition, in step S1020, the LoS MIMO-related setting information sent from the base station to the receiving terminal may further include information on whether the transmitting terminal supports LoS MIMO.

As another example, after transmitting the SL CSI-RS for LoS MIMO to the receiving terminal, the transmitting terminal may determine whether the receiving terminal supports LoS MIMO based on feedback information from the receiving terminal. Since patterns, antenna ports, and occupied resources of SL CSI-RS for LoS MIMO are different from patterns, antenna ports, and occupied resources of legacy CSI-RS, they can be distinguished from each other.

As another example, the pattern, antenna port, occupied resource, etc. of SL CSI-RS for LoS MIMO may be used the same as the pattern, antenna port, occupied resource, etc. of legacy CSI-RS.

If the receiving terminal does not support LoS MIMO, feedback information about CSI-RS for LoS MIMO is not transmitted. The transmitting terminal recognizes that the receiving terminal does not support LoS MIMO when the feedback information about the CSI-RS for LoS MIMO is not received. That is, the transmitting terminal can implicitly check whether the receiving terminal supports LoS MIMO without separate signaling from the receiving terminal.

Meanwhile, the transmitting terminal may inform the receiving terminal that it supports LoS MIMO using system information as shown in FIG. 8 and set the sidelink between the transmitting terminal and the receiving terminal to the LoS MIMO mode.

In addition, step S1040 includes generating a sidelink signal for each layer defined by LoS MIMO by the transmitting terminal, and transmitting the sidelink signal to the receiving terminal through a corresponding layer. The receiving terminal sets its receiving antenna to the LoS MIMO mode, and receives and decodes sidelink signals for each layer.

The present invention may include a LoS MIMO configuration procedure of another embodiment in which step S1000 of FIG. 10 is omitted.

11 is a flowchart illustrating a LoS MIMO configuration procedure for sidelink according to another example. 11 is an embodiment in which a transmitting terminal and a receiving terminal exchange RRC messages.

Referring to FIG. 11, a transmitting terminal and a receiving terminal may exchange capability information indicating whether to support LoS MIMO (S1000). A procedure for checking information about whether LoS MIMO is available between the base station and the terminal and which LoS MIMO can be supported when there are various LoS MIMO options is required. The capability information may indicate which of various LoS MIMO schemes the transmitting terminal and the receiving terminal will support. Here, various LoS MIMO schemes are linear polarization antenna (Vertical-Horizontal, Cross Polarization (X-pole, ±45 degrees)), circular polarization antenna (left-circular, right-circular), elliptical polarization antenna (Elliptical Polarization), or In addition, one or more of the more complex methods may be included. For example, the capability information may indicate that LoS MIMO based on vertical-horizontal polarization is supported. If vertical-horizontal polarization and X-polarization are distinguished, the terminal can support up to 4 layers with LoS MIMO. In this case, the capability information may indicate that both vertical-horizontal polarization and X-polarization are supported.

The transmitting terminal may determine whether to support the LoS MIMO mode for the receiving terminal (S1110). Step S1110 may be omitted in some cases. The transmitting terminal generates an RRC message including LoS MIMO-related configuration information and transmits it to the receiving terminal (S1120).

If, in step S1110, it is determined that the transmitting terminal does not support the LoS MIMO operation, the RRC message may not include LoS MIMO-related configuration information.

As an example, the LoS MIMO-related setting information included in the RRC message in step S1120 may be setting information for LoS MIMO.

As another example, the LoS MIMO-related setting information included in the RRC message in step S1120 is detailed setting information for LoS MIMO, and basic setting information for LoS MIMO may be transmitted in advance through system information. For example, if LoS MIMO-related setting information is A and B, A is basic setting information for LoS MIMO and is transmitted in system information, and B is detailed setting information for LoS MIMO and is transmitted in RRC signaling after RRC connection. It can be.

If the transmitting terminal supports a plurality of frequency bands, the transmitting terminal may vary whether to support LoS MIMO or support method for each frequency band. In this case, the transmitting terminal may include information about this in an RRC message and transmit it. For example, assume that a transmitting terminal supports a first frequency band and a second frequency band. The transmitting terminal may identify that LoS MIMO is supported for the first frequency band and that LoS MIMO is not supported for the second frequency band in the RRC message. Alternatively, the transmitting terminal may identify LoS MIMO supported for the first frequency band and a LoS MIMO support method in the RRC message, and identify that LoS MIMO is not supported for the second frequency band.

After receiving the RRC message from the transmitting terminal, the receiving terminal identifies LoS MIMO-related configuration information (S1130). If LoS MIMO-related configuration information indicates LoS MIMO support, the transmitting terminal and the receiving terminal may transmit and receive signals based on LoS MIMO (S1140). Here, the signals transmitted and received in step S1140 include sidelink reference signals such as SL CSI-RS and SL DM-RS, and sidelink physical channels such as PSBCH, PSDCH, PSCCH (physical sidelink, PSSCH, and PSFCH).

3. LoS MIMO control procedure in MAC layer

12 is a flowchart illustrating a LoS MIMO control procedure for sidelink according to an example.

Referring to FIG. 12 , in a state in which LoS MIMO-related settings are completed for the transmitting terminal and the receiving terminal, the transmitting terminal may transmit LoS MIMO control information indicating whether to activate or deactivate the LoS MIMO mode to the receiving terminal (S1200). Here, the preset procedure related to LoS MIMO may be performed by any one of the methods of FIGS. 8 to 9 described above.

As an example, LoS MIMO related control information may be included in a MAC message or a MAC control element (CE). For example, when a transmitting terminal supports multiple frequency bands, the LoS MIMO-related control information may indicate activation/deactivation of the LoS MIMO mode for each frequency band. Alternatively, when the transmitting terminal supports CA (carrier aggregation), the LoS MIMO-related control information may indicate activation/deactivation of the LoS MIMO mode for each serving cell.

Upon receiving the MAC message, the receiving terminal may identify LoS MIMO control information and activate or deactivate the LoS MIMO mode according to an indication of the LoS MIMO control information (S1210).

Alternatively, the receiving terminal receiving the MAC message may identify the LoS MIMO control information and activate or deactivate the LoS MIMO mode for each frequency or each serving cell according to the instructions of the LoS MIMO control information.

If the LoS MIMO-related control information indicates activation of the LoS MIMO mode, the transmitting terminal transmits and receives signals with the receiving terminal based on LoS MIMO (S1220). Step S1220 includes generating, by the transmitting terminal, a sidelink signal for each layer defined by LoS MIMO, and transmitting the sidelink signal to the receiving terminal through a corresponding layer. The receiving terminal sets its receiving antenna to the LoS MIMO mode, and receives and decodes sidelink signals for each layer.

4. LoS MIMO control procedure in physical layer

13 is a flowchart illustrating a LoS MIMO control procedure for sidelink according to another example.

Referring to FIG. 13 , in a state in which LoS MIMO related settings are completed, the transmitting terminal may transmit LoS MIMO control information to the receiving terminal to the terminal (S1300). Here, the preset procedure related to LoS MIMO may be performed by any one of the methods of FIGS. 8 to 12 described above, and the activation/deactivation procedure of the LoS MIMO mode may be performed by the method of FIG. 10 .

As an example, LoS MIMO related control information may be included in sidelink control information (SCI). For example, the LoS-related control information included in the SCI (i.e., SL grant) for sidelink scheduling is the number of layers in the sidelink LoS MIMO mode, the MCS level for each layer, and the sidelink LoS MIMO where beamforming is applied. In this case, at least some of beam information (TCI state value, etc.), precoding in sidelink LoS MIMO mode, and transmission mode information indicating sidelink LoS MIMO may be included. Here, the existing PMI may not be used in the LoS MIMO system. In this case, the PMI value may mean information related to precoding applied in the LoS MIMO system.

As another example, LoS MIMO related control information may include other physical layer control information for controlling LoS MIMO.

Upon receiving the SCI, the receiving terminal may identify LoS MIMO control information and activate or deactivate the LoS MIMO mode according to an indication of the LoS MIMO control information (S1310).

Alternatively, the terminal receiving the SCI may identify LoS MIMO control information and activate or deactivate the LoS MIMO mode for each frequency or each serving cell according to the instructions of the LoS MIMO control information.

If LoS MIMO-related control information indicates activation of the LoS MIMO mode, the transmitting terminal and the receiving terminal transmit and receive sidelink signals based on LoS MIMO (S1320). Step S1320 includes generating, by the transmitting terminal, a sidelink signal for each layer defined by LoS MIMO, and transmitting the sidelink signal to the receiving terminal through a corresponding layer. The receiving terminal sets its receiving antenna to the LoS MIMO mode, and receives and decodes sidelink signals for each layer.

5. Design of New SideLink (SL) DM-RS for LoS MIMO in Sidelink

A demodulation reference signal (DM-RS) for LoS MIMO is designed in a different way from a conventional SL DM-RS (hereinafter referred to as a legacy SL DM-RS) designed for the purpose of beamforming or spatial multiplexing. That is, the SL DM-RS for LoS MIMO may be defined or designed differently from the legacy SL DM-RS in DM-RS configuration or pattern, resource mapping method, antenna port setting, and density. This means that the legacy SL DM-RS and the SL DM-RS for LoS MIMO coexist on the resource grid. SL DM-RS for LoS MIMO is defined separately from legacy SL DM-RS.

As an example, an SL DM-RS for LoS MIMO may have a specific antenna port number. Among all SL DM-RS antenna port numbers, some may be allocated as legacy SL DM-RS antenna ports, and some may be allocated as SL DM-RS antenna ports for LoS MIMO. For example, if there are a total of 16 SL DM-RS antenna ports, legacy SL DM-RS antenna ports may be 0 to 7, and SL DM-RS antenna ports for LoS MIMO may be 8 to 15.

In a LoS MIMO system based on a vertical-horizontal (V-H) polarized antenna, an SL DM-RS antenna port for a vertical antenna and an SL DM-RS antenna port for a horizontal antenna may be different. If a vertical-horizontal polarization antenna and an X-polarization antenna are combined, or if the number of LoS MIMO layers increases, SL DM-RS may be further added accordingly.

When LoS MIMIO and beamforming are combined, SL DM-RS may be added and used for each beamformed channel.

If the distance between the terminals increases, the distinction of layers for LoS MIMO may not be clear. This may cause deterioration of reception performance. To compensate for this, frequency/time resources of SL DM-RS for LoS MIMO can be designed to be denser than legacy SL CSI-RS. A method of adaptively adjusting the density of SL DM-RS for LoS MIMO according to channel conditions or BLER (Block Error Rate) may be used. For example, if the distance between terminals exceeds a certain distance, the density of SL DM-RS for LoS MIMO is increased. The density of RS can be lowered. However, as the density of SL DM-RS for LoS MIMO increases, resources that can be allocated to data decrease, so there is a trade-off in that transmission speed decreases.

14 is a flowchart illustrating a method of transmitting an SL DM-RS according to an example.

Referring to FIG. 14, the transmitting terminal generates an SL DM-RS for LoS MIMO (S1400). Step S1400 is a step of mapping the sequence for the SL DM-RS generated by the transmitting terminal to a specific time/frequency resource and layer, generating an SL signal for each layer defined by LoS MIMO, and each and transmitting the SL signal to the terminal. Here, a process of mapping different data to each layer by applying LoS MIMO may be different from general SU-MIMO or MU-MIMO.

As an example, the location of the time/frequency resource to which the SL DM-RS is mapped may be determined based on an equation in which at least one parameter related to LoS MIMO is used as a variable. For example, when the polarization value is p, p = 0 indicates vertical polarization and p = 1 indicates horizontal polarization. A frequency resource may be determined.

As another example, in a LoS MIMO system based on a vertical-horizontal (V-H) polarized antenna, the SL DM-RS pattern for a vertical antenna and the SL DM-RS pattern for a horizontal antenna may be different. The SL DM-RS pattern for LoS MIMO may be set in a different way from the legacy SL DM-RS pattern. This setting may be performed by separate RRC signaling.

When LoS MIMIO and SL beamforming are combined, SL DM-RS may be added and used for each beamformed channel.

The transmitting terminal transmits the PSSCH including the SL DM-RS for LoS MIMO to the receiving terminal (S1410).

Upon receiving the PSSCH, the receiving terminal decodes the PSSCH based on the SL DM-RS for LoS MIMO (S1420). The receiving terminal sets its receiving antenna to the LoS MIMO mode, performs channel estimation based on the SL DM-RS for LoS MIMO, and then receives and decodes the SL signal for each layer.

6. Design of New SL CSI-RS for LoS MIMO in Sidelink

15 is a flowchart illustrating a method of transmitting SL CSI-RS according to an example.

Referring to FIG. 15, the transmitting terminal generates an SL CSI-RS for LoS MIMO (S1500). Step S1500 includes generating a sequence for the SL CSI-RS by the transmitting terminal.

As an example, an SL CSI-RS for LoS MIMO may have a specific antenna port number. Among all SL CSI-RS antenna port numbers, some may be allocated as legacy SL CSI-RS antenna ports, and the remaining portions may be allocated as SL CSI-RS antenna ports for LoS MIMO. For example, if there are a total of 64 SL CSI-RS antenna ports, legacy SL CSI-RS antenna ports may be 0 to 31, and SL CSI-RS antenna ports for LoS MIMO may be 32 to 63.

In a LoS MIMO system based on a vertical-horizontal (V-H) polarized antenna, an SL CSI-RS antenna port for a vertical antenna and a SL CSI-RS antenna port for a horizontal antenna may be different. If a vertical-horizontal polarization antenna and an X-polarization antenna are combined or the number of LoS MIMO layers increases, SL CSI-RSs may be further added accordingly.

When LoS MIMIO and beamforming are combined, SL CSI-RS may be used separately.

The transmitting terminal transmits the SL CSI-RS for LoS MIMO and the legacy SL CSI-RS to the receiving terminal (S1510). Step S1510 includes mapping and transmitting, by the transmitting terminal, the sequence for the SL CSI-RS generated in step S1500 to a specific time/frequency resource.

As an example, the location of the time/frequency resource to which the SL CSI-RS is mapped may be determined based on an equation using at least one parameter related to LoS MIMO as a variable. For example, when the polarization value is p, p = 0 indicates vertical polarization and p = 1 indicates horizontal polarization. A frequency resource may be determined.

As another example, in a LoS MIMO system based on a vertical-horizontal (V-H) polarized antenna, the SL CSI-RS pattern for a vertical antenna and the SL CSI-RS pattern for a horizontal antenna may be different. The SL CSI-RS pattern for LoS MIMO may be set in a different way (SL CSI-RS transmission period, number of times, etc.) from the legacy SL CSI-RS pattern. This setting may be performed by separate RRC signaling.

The receiving terminal performs channel estimation based on the SL CSI-RS for LoS MIMO and generates feedback information (S1520). Here, the feedback information is an indicator indicating whether LoS MIMO is possible, a channel state information report, and at least some of a precoding matrix indicator (PMI), a rank indicator (RI), and a channel quality indicator (CQI). can include The receiving terminal transmits the number of possible layers, a channel state measurement value (CQI, etc.) for each layer, a candidate PMI value, etc. to the transmitting terminal using SL CSI-RS for LoS MIMO.

A method of performing channel estimation based on the SL CSI-RS for LoS MIMO may be different from a channel estimation method based on the legacy SL CSI-RS.

In the case of channel estimation based on the legacy SL CSI-RS, the receiving terminal calculates a rank based on the legacy MIMO antenna structure and the legacy SL CSI-RS. Since the rank becomes 1 in the LoS situation, the receiving terminal generates feedback information indicating rank indicator = 1 and reports it to the transmitting terminal, and the transmitting terminal cannot perform SM.

On the other hand, in the case of channel estimation based on the SL CSI-RS for LoS MIMO, the receiving terminal calculates a first rank based on the legacy SL CSI-RS and calculates a second rank based on the SL CSI-RS for LoS MIMO do. In the LoS situation, the first rank is 1, but the second rank may be greater than 1. The receiving terminal generates feedback information in which the first rank indicator = 1 and the second rank indicator > 1 and reports it to the transmitting terminal. That is, the receiving terminal measures how many layers can be distinguished for LoS MIMO, and calculates and reports a channel state value (eg, CQI value) of each layer. In addition, the transmitting terminal may determine whether LoS MIMO can be performed, the number of layers, and the MCS level for each layer based on the second rank indicator, and perform SM based on LoS MIMO.

Meanwhile, when LoS MIMO is used, since beamforming may be applied to each layer (or each polarization), a codebook and precoding for the case of applying LoS MIMO may be used. In this case, the codebook and precoding for LoS MIMO are designed differently from legacy beamforming or SM, and the RF chain or connection path of the transceiver-RF-antenna for actual implementation may be different.

For example, in the case of LoS MIMO based on a vertical-horizontal polarization antenna, a transmitter performs first beamforming using a plurality of vertical antennas, and a second beam different from the first beamforming using a plurality of horizontal antennas. Foaming can also be performed. In this case, codebooks and/or precoding matrices for vertical polarization and horizontal polarization may be separately applied.

Here, a separate SL DM-RS for LoS MIMO is required to coherent demodulate a signal transmitted to each layer.

The receiving terminal transmits feedback information to the transmitting terminal (S1530).

The transmitting terminal determines whether to apply LoS MIMO (or whether to switch to LoS MIMO mode) based on the feedback information (S1540).

If it is determined to apply LoS MIMO, the transmitting terminal transmits and receives signals with the receiving terminal based on LoS MIMO (S1550). In the case of sidelink transmission, step S1550 includes generating a sidelink signal for each layer defined by LoS MIMO by a transmitting terminal, and transmitting each sidelink signal to a receiving terminal through a corresponding layer. The terminal sets its reception antenna to the LoS MIMO mode, and receives and decodes sidelink signals for each layer.

16 shows a transmitting terminal and a receiving terminal in which an embodiment of the present invention is implemented.

Referring to FIG. 16 , a transmitting terminal 1600 includes a processor 1611, a memory 1612, and a transceiver 1613. Processor 1611 may be configured to implement the functions, processes and/or methods described herein. Layers of the air interface protocol may be implemented in the processor 1611. For example, the processor 1611 may process LoS MIMO-related setting information and/or LoS MIMO-related control information of the transmitting terminal according to FIGS. 8 to 11 .

The memory 1612 is connected to the processor 1611 and stores various information for driving the processor 1611 . The transceiver 1613 is connected to the processor 1611 and transmits a sidelink signal to the receiving terminal 1650 in LoS MIMO mode or receives a sidelink signal from the receiving terminal 1650 in LoS MIMO mode. The transceiver 1613 includes a linear polarization antenna (Vertical-Horizontal, Cross Polarization (X-pole, ±45 degrees)), a circular polarization antenna (left-circular, right-circular), and an elliptical polarization antenna to support the aforementioned LoS MIMO system. Elliptical Polarization, or one or more of the more complex schemes.

The receiving terminal 1650 includes a processor 1651, a memory 1652, and a transceiver 1653. Processor 1651 may be configured to implement the functions, processes and/or methods described herein. Layers of the air interface protocol may be implemented in the processor 1651. The memory 1652 is connected to the processor 1651 and stores various information for driving the processor 1651 . The transceiver 1653 is connected to the processor 1651 and transmits a sidelink signal to the transmitting terminal 1600 or receives a sidelink signal from the transmitting terminal 1600 .

The processors 1611 and 1651 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and/or data processing devices. The memories 1612 and 1652 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The transceivers 1613 and 1653 may include baseband circuits for processing radio frequency signals. When the embodiment is implemented as software, the above-described technique may be implemented as a module (process, function, etc.) that performs the above-described functions. The module may be stored in the memories 1612 and 1652 and executed by the processors 1611 and 1651 . The memories 1216 and 1652 may be internal or external to the processors 1611 and 1651 and may be connected to the processors 1611 and 1651 by various well-known means.

In the exemplary system described above, methods that may be implemented in accordance with the features of the present invention described above have been described on the basis of flowcharts. Although methods are described as a series of steps or blocks for convenience, the claimed inventive feature is not limited to the order of the steps or blocks, and some steps may occur concurrently or in a different order than described above with other steps. Further, those skilled in the art will understand that the steps shown in the flowcharts are not exclusive, and that other steps may be included or one or more steps of the flowcharts may be deleted without affecting the scope of the present invention.

Claims (20)

In a method performed by a first terminal in a wireless communication system supporting Line of Sight (LoS) Multiple Input Multiple Output (MIMO),
Receiving configuration information related to the LoS MIMO from a base station, and
Perform sidelink communication with a second terminal based on the LoS MIMO based on the configuration information,
The LoS MIMO is MIMO in which transmission and reception of a plurality of layers based on line of sight is supported,
The sidelink communication includes LoS MIMO transmission for transmitting a plurality of transmission signals using a plurality of transmission antennas of the first terminal and LoS MIMO reception for receiving a plurality of reception signals using a plurality of reception antennas of the first terminal. A method comprising a. According to claim 1,
The setting information includes a rank related to at least one of the LoS MIMO transmission and the LoS MIMO reception, information related to precoding related to at least one of the LoS MIMO transmission and the LoS MIMO reception, and the plurality of Characterized in that for indicating some or all of the transmission signals and a Modulation and Coding Scheme (MCS) related to the plurality of received signals. According to claim 1,
The method of claim 1, wherein the setting information indicates a frequency band in which the LoS MIMO transmission and the LoS MIMO reception are supported. According to claim 3,
Wherein the first terminal performs the LoS MIMO transmission and the LoS MIMO reception on the frequency band. According to claim 1,
The setting information is transmitted through at least one of a radio resource control (RRC) message, a medium access control-control element (MAC-CE), and downlink control information (DCI). According to claim 1,
The method characterized in that the setting information is transmitted through a system information block (System Information Block) or a master information block (Master Information Block). According to claim 1,
The plurality of transmit antennas and the plurality of receive antennas are configured based on at least one of a vertical-horizontal polarization (VH) structure, a cross polarization structure, a cyclic polarization structure, and an elliptical polarization structure. How to. A first terminal in a wireless communication system supporting Line of Sight (LoS) Multiple Input Multiple Output (MIMO),
one or more memories to store instructions;
one or more transceivers; and
one or more processors coupling the one or more memories and the one or more transceivers, wherein the one or more processors execute the instructions,
Receiving configuration information related to the LoS MIMO from a base station, and
Perform sidelink communication with a second terminal based on the LoS MIMO based on the configuration information,
The LoS MIMO is MIMO in which transmission and reception of a plurality of layers based on line of sight is supported,
The sidelink communication includes LoS MIMO transmission for transmitting a plurality of transmission signals using a plurality of transmission antennas of the first terminal and LoS MIMO reception for receiving a plurality of reception signals using a plurality of reception antennas of the first terminal. containing
Device. According to claim 8,
The setting information includes a rank related to at least one of the LoS MIMO transmission and the LoS MIMO reception, information related to precoding related to at least one of the LoS MIMO transmission and the LoS MIMO reception, and the plurality of Indicating some or all of the transmission signals and Modulation and Coding Scheme (MCS) related to the plurality of received signals
Device. According to claim 8,
The configuration information indicates a frequency band in which the LoS MIMO transmission and the LoS MIMO reception are supported.
Device. According to claim 10,
The first terminal performs the LoS MIMO transmission and the LoS MIMO reception on the frequency band
Device. According to claim 8,
The setting information is transmitted through at least one of a Radio Resource Control (RRC) message, a Medium Access Control-Control Element (MAC-CE), and Downlink Control Information (DCI)
Device. According to claim 8,
The setting information is transmitted through a system information block (System Information Block) or a master information block (Master Information Block)
Device. According to claim 8,
The plurality of transmit antennas and the plurality of receive antennas are configured based on at least one of a vertical-horizontal polarization (VH) structure, a cross polarization structure, a cyclic polarization structure, and an elliptical polarization structure
Device. An apparatus configured to control a first terminal in a wireless communication system supporting Line of Sight (LoS) Multiple Input Multiple Output (MIMO), the apparatus comprising:
one or more processors; and
one or more memories executablely coupled by the one or more processors and storing instructions, wherein the one or more processors execute the instructions;
Receiving configuration information related to the LoS MIMO from a base station, and
Perform sidelink communication with a second terminal based on the LoS MIMO based on the configuration information,
The LoS MIMO is MIMO in which transmission and reception of a plurality of layers based on line of sight is supported,
The sidelink communication includes LoS MIMO transmission for transmitting a plurality of transmission signals using a plurality of transmission antennas of the first terminal and LoS MIMO reception for receiving a plurality of reception signals using a plurality of reception antennas of the first terminal. A device comprising a. According to claim 15,
The setting information includes a rank related to at least one of the LoS MIMO transmission and the LoS MIMO reception, information related to precoding related to at least one of the LoS MIMO transmission and the LoS MIMO reception, and the plurality of An apparatus characterized in that instructing some or all of transmission signals and a Modulation and Coding Scheme (MCS) related to the plurality of received signals. According to claim 15,
The apparatus, characterized in that the setting information indicates a frequency band in which the LoS MIMO transmission and the LoS MIMO reception are supported. According to claim 17,
Wherein the first terminal performs the LoS MIMO transmission and the LoS MIMO reception on the frequency band. According to claim 15,
The configuration information is transmitted through at least one of a radio resource control (RRC) message, a medium access control-control element (MAC-CE), and downlink control information (DCI). According to claim 15,
The device, characterized in that the setting information is transmitted through a system information block (System Information Block) or a master information block (Master Information Block).

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