KR20210102015A - Method and apparatus for transmission and reception of broadcast information in wireless communication system - Google Patents

Abstract

The present disclosure relates to a communication technique that converges a 5G communication system for supporting a higher data rate after a 4G system with IoT technology, and a system thereof. And the present invention is based on 5G communication technology and IoT-related technology that can be applied to intelligent services (eg, a smart home, a smart building, a smart city, a smart car or a connected car, a healthcare, a digital education, a retail business, security and safety-related services, etc.). Disclosed are a method for transmission and reception of broadcast information in wireless communication system and a device.

Description

Method and apparatus for transmitting and receiving broadcast information in a wireless communication system

The present disclosure relates to a method for transmitting and receiving broadcast information in a wireless communication system, and more particularly, to a configuration of broadcast information in a sidelink communication system, and a method and apparatus for transmitting and receiving the same.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system in order to meet the increasing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a system after the 4G network (Beyond 4G Network) communication system or after the LTE system (Post LTE). The 5G communication system defined by 3GPP is called the New Radio (NR) system.

In order to achieve a high data rate, the 5G communication system is being considered for implementation in a very high frequency (mmWave) band (eg, such as a 60 gigabyte (60 GHz) band). In order to mitigate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna techniques have been discussed and applied to the NR system.

In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), and an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and reception interference cancellation Technology development is underway.

In addition, in the 5G system, Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), which are advanced coding modulation (ACM) methods, and Filter Bank Multi Carrier (FBMC), NOMA, which are advanced access technologies, (non-orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life can be provided. IoT is the field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, 5G communication such as sensor network, machine to machine (M2M), and machine type communication (MTC) is being implemented by techniques such as beamforming, MIMO, and array antenna. The application of a cloud radio access network (cloud RAN) as the big data processing technology described above is an example of the convergence of 5G technology and IoT technology.

As various services can be provided according to the above-mentioned and the development of mobile communication systems, a method for effectively providing these services is required.

The present disclosure relates to a method of configuring sidelink broadcast information in a sidelink communication system, and a method and apparatus for transmitting and receiving the same.

The present invention for solving the above problems is a control signal processing method in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting a second control signal generated based on the processing to the base station.

According to the proposed embodiment, the efficiency of a method of configuring sidelink broadcast information and a process of transmitting and receiving it in a sidelink communication system can be improved.

1 is a diagram of a system for explaining an embodiment of the present disclosure.
2 is a diagram illustrating a vehicle to everything (V2X) communication method through a sidelink to which an embodiment of the present disclosure is applied.
3 is a diagram illustrating a protocol of a sidelink terminal to which an embodiment of the present disclosure is applied.
4 is a diagram illustrating types of synchronization signals that can be received by a sidelink terminal to which an embodiment of the present disclosure is applied.
5 is a diagram illustrating a frame structure of a sidelink system according to an embodiment of the present disclosure.
6 is a diagram illustrating a structure of a sidelink synchronization channel according to an embodiment of the present disclosure.
7A is a diagram illustrating a method of transmitting a sidelink synchronization signal according to an embodiment of the present disclosure.
7B is a diagram illustrating a method of transmitting a sidelink synchronization signal according to an embodiment of the present disclosure.
8 is a diagram illustrating a method of transmitting a sidelink synchronization signal according to another embodiment of the present disclosure.
9 is a diagram illustrating an uplink-downlink configuration within a base station coverage according to an embodiment of the present disclosure.
10 is a table showing the number of uplink-downlink symbols occupied by 14 symbols constituting one slot according to an embodiment of the present disclosure.
11 is a diagram illustrating a situation in which information is transmitted and received between side link terminals according to an embodiment.
12 is a diagram illustrating a type of a link through which a sidelink terminal may perform sidelink communication according to an embodiment of the present disclosure.
13 is a diagram illustrating a sidelink synchronization procedure according to an embodiment of the present disclosure.
14 is another diagram illustrating a sidelink synchronization procedure according to an embodiment of the present disclosure.
15 is a diagram illustrating a structure of a terminal according to an embodiment of the present disclosure.
16 is a diagram illustrating a structure of a base station according to an embodiment of the present disclosure.
17 is a diagram illustrating sidelink resource information received by a sidelink terminal according to an embodiment of the present disclosure.
18 is a diagram illustrating a method of setting sidelink resource information according to an embodiment of the present disclosure.
19 is a diagram illustrating a slot structure according to subcarrier spacing according to an embodiment of the present disclosure.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. At this time, it should be noted that in the accompanying drawings, the same components are denoted by the same reference numerals as much as possible. In addition, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted.

In describing the embodiments, descriptions of technical content that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to more clearly convey the gist of the present disclosure without obscuring the gist of the present disclosure by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present disclosure, and methods for achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the present disclosure to be complete, and those of ordinary skill in the art to which the present disclosure pertains. It is provided to fully inform the reader of the scope of the present disclosure, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible that the instructions stored in the flow chart block(s) produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in blocks to occur out of order. For example, two blocks shown one after another may in fact be performed substantially simultaneously, or it is possible that the blocks are sometimes performed in the reverse order according to the corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA or ASIC, and '~ unit' performs certain roles. However, '-part' is not limited to software or hardware. The '~ unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' denotes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card. Also, in an embodiment, '~ unit' may include one or more processors.

In describing the embodiments of the present disclosure in detail, the wireless access network New Radio (NR) and the core network packet core (5G System, or 5G Core Network, or NG Core: Next Generation Core) is the main object, but the main gist of the present disclosure is applicable to other communication systems having a similar technical background with slight modifications within the scope not significantly departing from the scope of the present disclosure, which It will be possible by the judgment of a person having technical knowledge skilled in the technical field of the present disclosure.

In the 5G system, in order to support network automation, a network data collection and analysis function (NWDAF), which is a network function that provides a function to analyze and provide data collected from a 5G network, may be defined. NWDAF can collect/store/analyze information from the 5G network and provide the results to unspecified network functions (Network Functions, NFs), and the analysis results can be used independently by each NF.

For convenience of description below, some terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP) standard (standards of 5G, NR, LTE, or similar systems) may be used. However, the present disclosure is not limited by terms and names, and may be equally applied to systems conforming to other standards.

In addition, a term for identifying an access node used in the following description, a term for a network entity (network entity), a term for messages, a term for an interface between network entities, and various identification information Terms and the like referring to them are exemplified for convenience of description. Therefore, it is not limited to the terms used in the present disclosure, and other terms referring to objects having equivalent technical meanings may be used.

Efforts are being made to develop an improved 5G communication system (ie, NR) to meet the increasing demand for wireless data traffic after the commercialization of the 4G communication system. In order to achieve high data rates, the 5G communication system is designed to enable resources in the very high frequency (mmWave) band (eg, the 28 GHz frequency band). In order to mitigate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, unlike LTE, the 5G communication system supports various subcarrier spacings such as 15 kHz, 30 kHz, 60 kHz, and 120 kHz, and the Physical Control Channel uses Polar Coding, The data channel (Physical Data Channel) uses LDPC (Low Density Parity Check). In addition, as a waveform for uplink transmission, not only discrete Fourier transform spread orthogonal frequency division multiplexing (OFDM) (DFT-S-OFDM) but also cyclic prefix based OFDM (CP-OFDM) are used. In LTE, Hybrid Automatic Repeat reQuest (HARQ) retransmission in units of TB (Transport Block) is resourced, whereas in 5G, CBG (Code Block Group)-based HARQ retransmission in which a plurality of CBs (Code Blocks) are bundled may be additionally resourced.

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication) are being implemented by 5G communication technologies such as beamforming, MIMO, and array antenna. . The application of a cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of the convergence of 3eG technology and IoT technology. As described above, a plurality of services may be provided to a user in a communication system, and in order to provide such a plurality of services to a user, a method and an apparatus using the same are required to provide each service within the same time period according to characteristics. . Various services provided in the 5G communication system are being studied, and one of them is a service that satisfies the requirements for low latency and high reliability.

In the case of vehicle communication, standardization of LTE-based V2X based on D2D (Device-to-Device) communication structure has been completed in 3GPP Rel-14 and Rel-15. Efforts are underway. In NR V2X, it is planned to support unicast communication, groupcast (or multicast) communication, and broadcast communication between the UE and the UE. In addition, NR V2X is different from LTE V2X, which aims to transmit and receive basic safety information necessary for vehicle road driving. Together, we aim to provide more advanced services.

Since the advanced service described above requires a high data rate, the NR V2X system may require a relatively wide bandwidth compared to the conventional 4G LTE V2X system. To this end, it is necessary to support operation in a high frequency band, and it is necessary to solve a coverage problem caused by frequency characteristics through analog beamforming. In such an analog beamforming system, a method and an apparatus for obtaining beam information between a transmitting terminal and a receiving terminal are required.

An embodiment of the present specification is proposed to support the above-described scenario, and an object of the present specification is to provide a method and apparatus for configuring sidelink broadcast information to perform sidelink synchronization between a terminal and a terminal, and a method and apparatus for transmitting and receiving the same do.

1 is a diagram of a system for explaining an embodiment of the present disclosure.

1a is an example of a case where all V2X terminals (UE-1 and UE-2) are located within the coverage of the base station.

All V2X terminals located within the coverage of the base station may receive data and control information from the base station through a downlink (DL) or transmit data and control information through an uplink (UL) to the base station. In this case, the data and control information may be data and control information for V2X communication. Alternatively, the data and control information may be data and control information for general cellular communication. In addition, V2X terminals can transmit and receive data and control information for V2X communication through a sidelink (Sidelink: SL).

1b is an example of a case in which UE-1 is located within the coverage of the base station among V2X terminals and UE-2 is located outside the coverage of the base station. The example according to FIG. 1B may be referred to as an example related to partial coverage.

UE-1 located within the coverage of the base station may receive data and control information from the base station through downlink or transmit data and control information through uplink to the base station.

UE-2 located outside the coverage of the base station cannot receive data and control information from the base station through downlink, and cannot transmit data and control information through uplink to the base station.

UE-2 may transmit and receive data and control information for V2X communication through a sidelink with UE-1.

1c is an example of a case where all V2X terminals are located outside the coverage of the base station.

Accordingly, UE-1 and UE-2 cannot receive data and control information from the base station through downlink, and cannot transmit data and control information through uplink to the base station.

UE-1 and UE-2 may transmit and receive data and control information for V2X communication through a sidelink.

1d is an example of a scenario of performing V2X communication between terminals located in different cells. Specifically, in FIG. 1d , a case in which the V2X transmitting terminal and the V2X receiving terminal are connected to different base stations (RRC connection state) or camping (RRC connection release state, that is, RRC idle state) is illustrated. In this case, UE-1 may be a V2X transmitting terminal and UE-2 may be a V2X receiving terminal. Alternatively, UE-1 may be a V2X receiving terminal, and UE-2 may be a V2X transmitting terminal. UE-1 may receive a V2X dedicated SIB (System Information Block) from the base station to which it is connected (or camping), and UE-2 is another It is possible to receive a V2X dedicated SIB from the base station. In this case, the information of the V2X dedicated SIB received by UE-1 and the information of the V2X dedicated SIB received by UE-2 may be the same or different from each other. When the SIB information is different from each other, UE-1 and UE-2 may receive different information for sidelink communication from a base station to which they are connected (or to which they are camping) as SIBs. In this case, it is necessary to unify information in order to perform sidelink communication between terminals located in different cells.

1 illustrates a V2X system composed of two terminals (UE-1 and UE-2) for convenience of explanation, but is not limited thereto. In addition, the uplink and downlink between the base station and the V2X terminals may be named a Uu interface, and the sidelink between the V2X terminals may be named a PC5 interface. Therefore, in the present disclosure, these may be used interchangeably.

On the other hand, in the present disclosure, the terminal is a terminal supporting terminal-to-device communication (Device-to-Device: D2D), a vehicle supporting vehicle-to-vehicle communication (Vehicular-to-Vehicular: V2V), and communication between vehicles and pedestrians (Vehicular- Vehicle or pedestrian handset (i.e. smartphone) supporting to-pedestrian: V2P), vehicle-to-vehicle communication (Vehicular-to-Network: V2N) supporting communication, or vehicle-to-vehicle communication ( It may mean a vehicle supporting Vehicular-to-Infrastructure: V2I). Also, in the present disclosure, the terminal may refer to a Road Side Unit (RSU) equipped with a terminal function, an RSU equipped with a base station function, or an RSU equipped with a part of a base station function and a part of a terminal function.

In the present disclosure, V2X communication may mean communication between terminals, communication between vehicles, or communication between vehicles and pedestrians, and may be used in combination with sidelink communication.

In addition, in the present disclosure, the base station defines in advance that it may be a base station supporting both V2X communication and general cellular communication, or a base station supporting only V2X communication. And in this case, the base station may mean a 5G base station (gNB), a 4G base station (eNB), or a road site unit (RSU). Accordingly, unless otherwise specified in the present disclosure, the base station and the RSU may be used interchangeably because the same concept may be used.

2 is a diagram illustrating a V2X communication method made through a sidelink to which an embodiment of the present disclosure is applied.

As shown in FIG. 2A , the transmitting terminal UE-1 and the receiving terminal UE-2 may perform one-to-one communication, which may be referred to as unicast communication.

As shown in Figure 2b, the transmitting terminal (UE-1 or UE-4) and the receiving terminal (UE-2, UE-3 or UE-5, UE-6, UE-7) perform one-to-many communication. and may be called a groupcast or multicast.

In FIG. 2B , UE-1, UE-2, and UE-3 form one group (group A) to perform groupcast communication, and UE-4, UE-5, and UE-6 , and UE-7 is a diagram illustrating that another group is formed (group B) to perform groupcast communication. Each terminal performs groupcast communication only within a group to which it belongs, and communication between different groups may be performed through one of unicast, groupcast, and broadcast communication. Although it is illustrated that two groups are formed in FIG. 2B , the present invention is not limited thereto.

Meanwhile, although not shown in FIG. 2 , V2X terminals may perform broadcast communication. Broadcast communication means a case in which all V2X terminals receive data and control information transmitted by a V2X transmitting terminal through a sidelink. As an example, when it is assumed in FIG. 2B that UE-1 is a transmitting terminal for broadcast, all terminals UE-2, UE-3, UE-4, UE-5, UE-6, and UE -7) may be a receiving terminal that receives data and control information transmitted by UE-1.

The sidelink unicast, groupcast, and broadcast communication method according to an embodiment of the present disclosure may be supported in in-coverage, partial-coverage, and out-of-coverage scenarios.

Resource allocation in the sidelink system may use the following method.

(1) Mode 1 resource allocation

It means a method of resource allocation scheduled by the base station (scheduled resource allocation). More specifically, in mode 1 resource allocation, the base station may allocate resources used for sidelink transmission to RRC-connected terminals in a dedicated scheduling method. The scheduled resource allocation method may be effective for interference management and resource pool management (dynamic allocation and/or semi-persistent transmission (SPS)) since the base station can manage sidelink resources. When the RRC connected mode terminal has data to transmit to other terminal(s), data to be transmitted to other terminal(s) using a radio resource control (RRC) message or a medium access control (MAC) control element (CE) It is possible to transmit information informing the base station that there is For example, the RRC message may be a sidelink terminal information (SidelinkUEInformation) or a terminal assistance information (UEAssistanceInformation) message. In addition, the MAC CE is a BSR MAC CE, SR ( scheduling request) may be applicable. The mode 1 resource allocation method can be applied when the V2X transmitting terminal is within the coverage of the base station because the sidelink transmitting terminal receives the resource scheduled by the base station.

(2) Mode 2 resource allocation

Mode 2 allows the sidelink transmitting terminal to autonomously select a resource (UE autonomous resource selection). More specifically, in mode 2, the base station provides a sidelink transmission/reception resource pool for the sidelink to the terminal as system information or an RRC message (eg, an RRCReconfiguration message, or a PC5-RRC message), and the This is a method in which a transmitting terminal receiving a transmitting/receiving resource pool selects a resource pool and resources according to a predetermined rule. In the above example, since the base station provides configuration information for the sidelink transmission/reception resource pool, it can be applied when the sidelink transmitting terminal and the receiving terminal are within the coverage of the base station. When the sidelink transmitting terminal and the receiving terminal exist outside the coverage of the base station, the sidelink transmitting terminal and the receiving terminal may perform a mode 2 operation in a preset transmission/reception resource pool. The UE autonomous resource selection method may include zone mapping, sensing-based resource selection, random selection, and the like.

(3) In addition, even if it exists in the coverage of the base station, resource allocation or resource selection may not be performed in the scheduled resource allocation or terminal autonomous resource selection mode. sidelink communication may be performed through the pool).

The sidelink resource allocation method according to the embodiment of the present disclosure may be applied to various embodiments of the present disclosure.

3 is a diagram illustrating a protocol of a sidelink terminal to which an embodiment of the present disclosure is applied.

Although not shown in FIG. 3 , application layers of UE-A and UE-B may perform service discovery. In this case, the service discovery may include a discovery of which sidelink communication method (unicast, groupcast, or broadcast) each terminal will perform. Accordingly, in FIG. 3 , it can be assumed that terminal-A and terminal-B recognize that they will perform unicast communication through a service discovery process performed in the application layer. The sidelink terminals may acquire information on a source identifier (ID) and a destination identifier (ID) for sidelink communication in the above-mentioned service discovery process.

When the service discovery process is completed, the PC-5 signaling protocol layer shown in FIG. 3 may perform a direct link connection setup procedure between terminals. In this case, security setting information for direct communication between terminals may be exchanged.

When the direct link connection setup between terminals is completed, a PC-5 radio resource control (RRC) setup procedure between terminals may be performed in the PC-5 RRC layer of FIG. 3 . In this case, information on the capabilities of UE-A and UE-B may be exchanged, and access stratum (AS) layer parameter information for unicast communication may be exchanged.

When the PC-5 RRC setup procedure is completed, UE-A and UE-B may perform unicast communication.

Although unicast communication has been described as an example in the above example, it can be extended to groupcast communication. For example, when terminal-A, terminal-B, and terminal-C not shown in FIG. 3 perform groupcast communication, as mentioned above, terminal-A and terminal-B are configured for unicast communication. Service discovery, direct link setup between terminals, and PC-5 RRC setup procedures can be performed. In addition, terminal-A and terminal-C may also perform service discovery for unicast communication, direct link setup between terminals, and PC-5 RRC setup procedures. Finally, terminal-B and terminal-C may perform service discovery for unicast communication, direct link setup between terminals, and PC-5 RRC setup procedures. That is, instead of performing a separate PC-5 RRC setup procedure for groupcast communication, a PC-5 RRC setup procedure for unicast communication is performed in each pair of transmitting and receiving terminals participating in groupcast communication. can be done However, in the groupcast method, it may not always be necessary to perform the PC5 RRC setting procedure for unicast communication. For example, a scenario of groupcast communication performed without PC5 RRC connection establishment may exist, and in this case, the PC5 connection establishment procedure for unicast transmission may be omitted.

The PC-5 RRC configuration procedure for unicast or groupcast communication can be applied to all of the in-coverage, partial coverage, and out-of-coverage methods shown in FIG. 1 . When terminals to perform unicast or groupcast communication exist within the base station coverage, the corresponding terminals may perform the PC-5 RRC setup procedure before or after performing downlink or uplink synchronization with the base station. .

4 is a diagram illustrating types of synchronization signals that can be received by a sidelink terminal to which an embodiment of the present disclosure is applied.

Specifically, the following sidelink synchronization signals may be received from various sidelink synchronization sources.

- The sidelink terminal may directly receive a synchronization signal from a Global Navigation Satellite System (GNSS) or a Global Positioning System (GPS).

* In this case, the sidelink synchronization signal source may be GNSS.

- The sidelink terminal may indirectly receive a synchronization signal from a Global Navigation Satellite System (GNSS) or a Global Positioning System (GPS).

* Receiving the synchronization signal indirectly from the GNSS means that the sidelink terminal-A receives the sidelink synchronization signal (SLSS) transmitted by the sidelink terminal-1 that is directly synchronized with the GNSS. can In this case, the sidelink terminal-A may receive a synchronization signal from the GNSS through a two-hop (hop). As another example, the sidelink terminal-2 synchronized with the SLSS transmitted by the sidelink terminal-1 synchronized with the GNSS may transmit the SLSS. Upon receiving this, the sidelink terminal-A may receive a synchronization signal from the GNSS through 3-hop. Similarly, the sidelink terminal-A may receive a synchronization signal from the GNSS through 3-hops or more.

* In this case, the sidelink synchronization signal source may be another sidelink terminal synchronized with GNSS.

- The sidelink terminal may directly receive a synchronization signal from an LTE base station (eNB).

* The sidelink terminal may directly receive a primary synchronization signal (PSS)/secondary synchronization signal (SSS) transmitted from an LTE base station.

* In this case, the sidelink synchronization signal source may be the eNB.

The sidelink terminal may indirectly receive a synchronization signal from an LTE base station (eNB).

* Receiving the synchronization signal indirectly from the eNB may mean that the sidelink terminal-A receives the SLSS transmitted by the sidelink terminal-1 directly synchronizing with the eNB. In this case, the sidelink terminal-A may receive a synchronization signal from the eNB through 2-hop. As another example, the sidelink terminal-2 synchronizing with the SLSS transmitted by the sidelink terminal-1 directly synchronizing with the eNB may transmit the SLSS. Upon receiving this, the sidelink terminal-A may receive a synchronization signal from the eNB through 3-hop. Similarly, the sidelink terminal-A may receive the synchronization signal from the eNB through three-hop or more.

* In this case, the sidelink synchronization signal source may be another sidelink terminal synchronized with the eNB.

- The sidelink terminal may indirectly receive the synchronization signal from the NR base station (gNB).

* Receiving the synchronization signal indirectly from the gNB may mean that another sidelink terminal-A receives an SLSS transmitted by sidelink terminal-1 directly synchronizing with the gNB. In this case, the sidelink terminal-A may receive a synchronization signal from the gNB through 2-hop. As another example, sidelink terminal-2 synchronizing with the SLSS transmitted by sidelink terminal-1 directly synchronizing with the gNB may transmit the SLSS. Upon receiving this, the sidelink terminal-A may receive a synchronization signal from the gNB through 3-hop. Similarly, sidelink terminal-A may receive a synchronization signal from the gNB through three-hops or more.

* In this case, the sidelink synchronization signal source may be another sidelink terminal synchronized with the gNB.

- Sidelink terminal-A may directly receive a synchronization signal from another sidelink terminal-B.

* When the sidelink terminal-B does not detect the SLSS transmitted from the GNSS, gNB, eNB, or another sidelink terminal as a synchronization signal source, the sidelink terminal-B may transmit the SLSS based on its own timing. Sidelink terminal-A may directly receive the SLSS transmitted by sidelink terminal-B.

* In this case, the sidelink synchronization signal source may be a sidelink terminal.

- Sidelink terminal-A may indirectly receive a synchronization signal from another sidelink terminal-B.

* Receiving the synchronization signal indirectly from the sidelink terminal-B may mean that the sidelink terminal-A receives the SLSS transmitted by the sidelink terminal-1 directly synchronizing with the sidelink terminal-B. . In this case, the sidelink terminal-A may receive the synchronization signal from the sidelink terminal-B through two-hop. As another example, sidelink terminal-2 synchronizing with SLSS transmitted by sidelink terminal-1 directly synchronizing with sidelink terminal-B may transmit the SLSS. Receiving this, sidelink terminal-A may receive a synchronization signal from sidelink terminal-B through 3-hop. Similarly, sidelink terminal-A may receive a synchronization signal from sidelink terminal-B through three-hops or more.

* In this case, the sidelink synchronization signal source may be another sidelink terminal synchronized with the sidelink terminal.

The sidelink terminal may receive a synchronization signal from the above-described various synchronization signal sources, and may perform synchronization with a synchronization signal transmitted from a synchronization signal source having a higher priority according to a preset priority.

For example, in the order of a synchronization signal having a high priority to a synchronization signal having a low priority, the following priorities may be preset.

- Case A

1) Synchronization signal transmitted from GNSS > 2) Synchronization signal transmitted by UE performing direct synchronization from GNSS > 3) Synchronization signal transmitted by UE performing synchronization indirectly from GNSS > 4) eNB or gNB Synchronization signal transmitted from (eNB/gNB) > 5) Synchronization signal transmitted by UE performing synchronization directly from eNB/gNB > 6) Synchronization signal transmitted by UE performing synchronization indirectly from eNB/gNB > 7) A synchronization signal transmitted by a UE that is not directly or indirectly performing synchronization with GNSS and eNB/gNB.

Case A is an example of a case in which the synchronization signal transmitted by the GNSS has the highest priority. Alternatively, a case in which a synchronization signal transmitted by an eNB or gNB (eNB/gNB) has the highest priority may be considered, and the following priorities may be set in advance.

- Case B

1) Synchronization signal transmitted from eNB/gNB > 2) Synchronization signal transmitted by UE performing synchronization directly from eNB/gNB > 3) Synchronization signal transmitted by UE performing synchronization indirectly from eNB/gNB > 4) Synchronization signal transmitted from GNSS > 5) Synchronization signal transmitted by UE performing direct synchronization from GNSS > 6) Synchronization signal transmitted by UE performing synchronization indirectly from GNSS > 7) GNSS, A synchronization signal transmitted by a UE that is not directly or indirectly performing synchronization with the eNB/gNB.

Whether the sidelink terminal should follow the priority of Case A or the priority of Case B may be set by the base station or set in advance. More specifically, when the sidelink terminal exists in the coverage of the base station (in-coverage), the base station determines whether the sidelink terminal should follow the priority of Case A or Case B through system information (SIB) or RRC signaling. can be set. If the sidelink terminal exists outside the coverage of the base station (out-of-coverage), it is determined in advance whether the sidelink terminal should perform the sidelink synchronization procedure according to which priority of either Case A or Case B. configuration) can be

On the other hand, when the base station configures the above-described Case A to the sidelink terminal through system information or RRC signaling, the base station determines that the sidelink terminal transmits the synchronization signal from the priority 4 (eNB or gNB (eNB/gNB)) in Case A. ), priority 5 (when synchronization is performed with a synchronization signal transmitted by a UE performing synchronization directly from the eNB/gNB), and priority 6 (synchronization is performed indirectly from the eNB/gNB) It can be additionally set whether or not to consider (when synchronizing with a synchronization signal transmitted by a terminal). That is, when the aforementioned Case A is set and it is additionally set to consider priority 4, priority 5, and priority 6, all priorities of the above-described Case A may be considered (that is, from priority 1 to priority). up to rank 7). On the other hand, if the above-described Case A is set and priority 4, priority 5, and priority 6 are not set to be considered, or the above-described Case A is set and priority 4, priority 5, and priority 6 are set If not considered, priority 4, priority 5, and priority 6 may be omitted in the above-described Case A (that is, only priority 1, priority 2, priority 3, and priority 7 are considered) .

The sidelink synchronization signal referred to in this specification may mean a sidelink synchronization signal block (S-SSB), and the S-SSB is a sidelink primary synchronization signal (S-PSS), a sidelink secondary synchronization signal ( S-SSS) and a sidelink broadcast channel (PSBCH: physical sidelink broadcast channel). In this case, the S-PSS may be composed of a Zadoff-Chu sequence or an M-sequence, and the S-SSS may be composed of an M-sequence or a gold sequence. Similar to PSS/SSS in a cellular system, a sidelink ID may be transmitted through only S-SSS, not a combination of S-PSS and S-SSS or a combination of both. The PSBCH may transmit master information block (MIB) for sidelink communication similar to a physical broadcast channel (PBCH) of a cellular system.

In the present disclosure, when the sidelink parameter is preset in the sidelink terminal, it is mainly applicable to a scenario in which the sidelink terminal is located outside the coverage of the base station (out-of-coverage scenario). In this case, the meaning that the parameter is preset in the terminal may be interpreted as using a value built into the terminal when the terminal is shipped. As another example, the sidelink terminal accesses the base station and may refer to a value previously obtained and stored through RRC configuration for the sidelink parameter information. As another example, although the sidelink terminal does not access the base station, it may mean a value previously obtained and stored for sidelink system information from the base station.

5 is a diagram illustrating a frame structure of a sidelink system according to an embodiment of the present disclosure.

5 illustrates that the system operates 1024 radio frames, but is not limited thereto. For example, a specific system may operate less than or more radio frames than 1024, and how many radio frames the system operates may be set by the base station or set in advance. More specifically, when the sidelink terminal is located in the coverage of the base station, the sidelink terminal may obtain information about the radio frame through the master information block (MIB) of the PBCH transmitted by the base station. When the sidelink terminal is located outside the coverage of the base station, the information on the radio frame may be preset in the sidelink terminal.

In FIG. 5 , the radio frame number and the system frame number may be treated the same. That is, the radio frame number '0' may correspond to the system frame number '0' and the radio frame number '1' may correspond to the system frame number '1'. One radio frame may consist of 10 sub-frames, and one sub-frame may have a length of 1 ms on the time axis. According to the subcarrier interval used in NR V2X, the number of slots constituting one subframe may vary as shown in FIG. 5 . For example, when using a 15 kHz subcarrier interval in NR V2X communication, one subframe may be equal to one slot. However, in the case of using a 30 kHz sub-carrier spacing and a 60 kHz sub-carrier spacing in NR V2X communication, one sub-frame may be equal to two slots and four slots, respectively. Although not shown in FIG. 5 , this may be applied even when a subcarrier spacing of 120 kHz or higher is used. That is, if the number of slots constituting one subframe is generalized, as the subcarrier interval increases based on the 15kHz subcarrier interval, the number of slots constituting one subframe ^{may increase to 2 n} , where n = 0 , 1, 2, 3,...

6 is a diagram illustrating a structure of a sidelink synchronization channel according to an embodiment of the present disclosure.

The sidelink synchronization channel may be represented by being replaced with a sidelink synchronization signal block (S-SSB), and one S-SSB may consist of 14 symbols as shown in FIG. 6 . One S-SSB may include a sidelink primary synchronization signal (S-PSS), a sidelink secondary synchronization signal (S-SSS), a physical sidelink broadcast channel (PSBCH), and a guard period (GAP). In this case, S-PSS and S-SSS may each consist of two OFDM symbols, PSBCH may consist of 9 OFDM symbols, and GAP may consist of one OFDM symbol.

At this time, as shown in FIG. 6, S-PSS is mapped to OFDM symbol indexes 1 and 2, S-SSS is mapped to OFDM symbol indexes 3 and 4, and GAP is the last OFDM symbol of S-SSB (ie, OFDM It can be mapped to symbol index 13). PSBCH may be mapped to the remaining OFDM symbols except for the S-PSS, S-SSS, and GAP. 6 illustrates that the S-PSS and the S-SSS are located in consecutive symbols, the S-PSS and the S-SSS may be located apart from each other with one symbol therebetween. That is, S-PSS is mapped to OFDM symbol indexes 1 and 2, S-SSS is mapped to OFDM symbol indexes 4 and 5, and PSBCH is mapped to OFDM symbol indexes 0, 3, 6, 7, 8, 9, 10, 11, 12 can be mapped. Meanwhile, although not shown in FIG. 6 , a demodulation reference signal (DMRS) may be transmitted to each OFDM symbol to which the PSBCH is mapped.

Meanwhile, information transmitted through the PSBCH may include at least one of the following information.

1. Frame number: This may be information indicating a frame number through which S-SSB (ie, S-PSS, S-SSS, and PSBCH) is transmitted. When the sidelink terminal transmitting the S-SSB is located within the coverage of the base station, the frame number may be set based on the system frame number of the base station in which the sidelink terminal is located. When the sidelink terminal transmitting the S-SSB is located outside the coverage of the base station, the frame number may be preset based on the frame number of the terminal transmitting the S-SSB. The frame number may consist of 10 bits.

2. Sublink and uplink configuration information: As shown in FIG. 1B , a sidelink terminal located within the coverage of a base station may perform sidelink communication with a sidelink terminal located outside the coverage of the base station (partial coverage scenario). In FIG. 1B , a base station in which UE-1 is located may be operating in a time division duplexing (TDD) system. In this case, although not shown in FIG. 1B and UE-2, sidelink signals transmitted by terminals located outside the coverage of the base station may cause interference. More specifically, when UE-1 receives control information and data information through downlink from the base station, the sidelink control information and data information transmitted by UE-2 interferes with the downlink signal received by UE-1. can cause In FIG. 1B , when UE-1 is located at the edge of the coverage of the base station (ie, far away from the base station) and UE-2 is located adjacent to UE-1, the interference problem may become serious. On the other hand, when UE-1 transmits control information and data information through uplink to the base station, the sidelink control information and data information transmitted by UE-2 interferes with the uplink signal of UE-1 received by the base station. can cause However, since UE-2 is farther away from the base station than UE-1, the received signal of UE-2 at the receiver of the base station may not cause much interference to the received signal of UE-1. In addition, compared to the receiver of UE-1, the base station can use more reception antennas, so that more advanced reception techniques such as interference cancellation can be used. Therefore, when comparing the case where the signal of UE-2 causes interference to the receiver of UE-1 and the case where the signal of UE-2 causes interference to the receiver of the base station, the former case has a greater effect on system performance can affect

In order to solve the interference problem in the TDD system, the sidelink terminal transmitting the S-SSB within the coverage of the base station has TDD configuration information set by the base station (that is, downlink that all terminals located within the coverage of the base station must follow). link and uplink configuration information) may be transmitted to a sidelink terminal located outside the coverage of the base station through the PSBCH. The sidelink terminal located outside the coverage of the base station receiving the information through the PSBCH, except for a downlink subframe, a special subframe, a downlink slot, and a flexible slot, an uplink subframe or A resource pool for transmitting and receiving sidelink control information and data information may be configured using only the uplink slot.

3. Slot index: As shown in FIG. 5 , one system frame may consist of a plurality of subframes. And, according to the subcarrier spacing, one subframe may consist of a plurality of slots. Accordingly, an indicator indicating in which slot of the indicated frame number the S-SSB is transmitted may be required. The slot index may mean information indicating an index of a slot in which the S-SSB is transmitted within the frame index indicated by the frame number. For example, subcarrier intervals of 15 kHz, 30 kHz, 60 kHz, and 120 kHz may consist of 10 slots, 20 slots, 40 slots, and 80 slots, respectively, in one frame composed of 10 ms. Accordingly, 7 bits may be required to transmit 80 slot indexes.

4. Coverage indicator: As mentioned in FIG. 4, when the synchronization signal of the base station is set to have a higher priority than the GNSS, the S-SSB transmitted by the sidelink terminal synchronized directly from the base station is any other sidelink It may have priority over the S-SSB transmitted by the UE. That is, the S-SSB transmitted by the sidelink terminal synchronized directly or indirectly with the GNSS and the S-SSB transmitted by the sidelink terminal synchronized directly or indirectly with the S-SSB transmitted by another sidelink terminal. It may have a higher priority. This may mean that the timing of the base station is transmitted to the sidelink terminal located outside the coverage of the base station through the sidelink terminal located in the coverage of the base station. In order to determine the priority, a 1-bit indicator indicating the coverage state may be included in the PSBCH. For example, when the 1-bit indicator is set to '1', it may mean that the sidelink terminal transmitting the PSBCH is located within the coverage of the base station. And when the 1-bit indicator is set to '0', it may mean that the sidelink terminal transmitting the PSBCH is located outside the coverage of the base station. Accordingly, the sidelink terminal receiving the PSBCH can determine whether the S-SSB it has received is transmitted from a sidelink terminal located within the coverage of the base station or from a sidelink terminal located outside the coverage of the base station. . Based on this, it can be determined to which S-SSB to synchronize sidelink (ie, selection of a sidelink synchronization signal source).

Meanwhile, in addition to the above-mentioned information, the PSBCH may include reserved bits not used in the current release. For example, a reserved bit composed of 2-bit or 1-bit may be included, which may be used for a later release terminal (ie, a release 16 sidelink terminal does not interpret the reserved bit, and a later release 17 and later release When the reserved bit is used for the introduction of a new sidelink function, the sidelink terminal after release 17 may interpret the bit).

7 is a diagram illustrating a method of transmitting a sidelink synchronization signal block according to an embodiment of the present disclosure.

In FIGS. 7A to 7B , a sidelink synchronization signal source terminal transmitting a sidelink synchronization signal block (S-SSB) receives information on a starting point at which the S-SSB is transmitted from the base station or is set in advance can receive More specifically, when the sidelink synchronization signal source is located in the coverage of the base station (in-coverage), the base station can transmit the S-SSB to the sidelink synchronization signal source terminal through system information (SIB) or RRC configuration information. You can set information about the starting point. In this case, the information on the S-SSB transmission start point may mean an offset, and the offset is a system frame number (SFN) of a base station to which a terminal to transmit S-SSB is located, as shown in FIG. 7 . It may mean a difference between slot 0 and the start slot of the period in which the actual S-SSB is transmitted.

On the other hand, when the sidelink signal source is located outside the coverage of the base station (out-of-coverage), information on the starting point for transmitting the S-SSB may be pre-configured in the terminal. In this case, the information on the S-SSB transmission start point may mean an offset, and the offset is a slot 0 of a direct frame number (DFN) 0 of a terminal that wants to transmit the S-SSB and an actual S-SSB. It may mean a difference from the start slot of the period in which is transmitted.

7A illustrates a case in which one offset is set (or preset), and FIG. 7B illustrates a case in which two offsets are set (or preset). A case in which one and two offsets are configured may have the same meaning as one and two time resources for S-SSB transmission are configured, respectively. Meanwhile, although not shown in FIGS. 7A to 7B , there may exist a case in which three offsets are set, and in this case, three time resources for S-SSB transmission may be set. When the sidelink terminal is located in the coverage of the base station, a maximum of one time resource for S-SSB transmission may be configured. When the sidelink terminal is located outside the coverage of the base station, up to three time resources for S-SSB transmission may be configured (or preset) (ie, two or three resources may be configured or preset). can).

7A to 7B, a 15 kHz subcarrier spacing (SCS) spacing is assumed, and in this case, one slot may have the same concept as one subframe. Although not shown in FIGS. 7A to 7B, when the subcarrier spacing ^{is defined as 15 kHz x 2 n} , when n is a positive integer (that is, the subcarrier spacing is greater than 15 kHz), 1 subframe consists of 2 ⁿ slots. can be Conversely, when n is a negative integer (ie, when the subcarrier spacing is less than 15 kHz), one slot may consist of 2 ⁿ subframes. In addition, since 15 kHz subcarrier spacing is assumed in FIGS. 7A to 7B , one system frame (or radio frame, radio frame) may consist of 10 slots. Meanwhile, one slot may always consist of 14 OFDM symbols as shown in FIG. 6 irrespective of the subcarrier spacing.

As described above, FIG. 7A shows that one time resource for S-SSB transmission is set. In this case, only one offset value indicating the start point of S-SSB transmission may be set. More specifically, the starting point at which the S-SSB is transmitted in FIG. 7A exemplifies the 3rd slot of the 1st SFN, which indicates that the S-SSB transmission starts after an offset of 13 slots based on the 0th slot of the 0th SFN. can mean Accordingly, the base station may set the offset value to 13 slots for the S-SSB transmitting terminal through system information or RRC signaling. Using the set offset value, the sidelink terminal may transmit the S-SSB in the corresponding slot. Similarly, the terminal located outside the base station coverage may transmit the S-SSB in the corresponding slot using the preset offset value. In this case, the S-SSB transmitted in the corresponding slot may have the structure shown in FIG. 7 to the structure described in FIG. 8 .

The S-SSB initially transmitted in the 3rd slot of the 1st SFN may be repeatedly transmitted every P slot period, as shown in FIG. 7A . The P value may be fixed or may be set from the base station through system information or RRC signaling (if the sidelink terminal is outside the base station coverage, it may be preset). It is assumed in FIG. 7A that P = 160 ms (160 subframes or 160 slots).

7B illustrates that two time resources for S-SSB transmission are configured. In this case, two offset values indicating the start point of S-SSB transmission may be set. As described above, when the sidelink terminal is located outside the coverage of the base station, two offset values may be preset. A terminal that has previously set time resources for two S-SSB transmissions through the two offset values does not transmit all of the S-SSBs to the two time resources, but an S-SSB to one of the two time resources. and may receive an S-SSB transmitted by another sidelink terminal from the remaining one resource. This may be to solve a half-duplexing problem in which S-SSB transmission and reception cannot be performed at the same time.

7B shows that the time resource for the first S-SSB transmission is located in slot 3 of SFN 1, which is 13 slots after slot 0 of SFN 0, as in FIG. 7A. Accordingly, the offset 1 value may be 13 slots as in FIG. 7A . In addition, in FIG. 7B , it is shown that the time resource for the second S-SSB transmission is located in the 8th slot of the 1st SFN, 18 slots after the 0th slot of the 0th SFN. Accordingly, the offset2 value may be 18 slots. Accordingly, the sidelink terminal may receive or transmit the S-SSB in the corresponding slot using the set offset values.

The S-SSB initially transmitted in the 3rd slot of the 1st SFN may be repeatedly transmitted every period of the P1 slot, as shown in FIG. 7B . The S-SSB initially transmitted in the 8th slot of the 1st SFN may be repeatedly transmitted every period of the P2 slot, as shown in FIG. 7B . The values of P1 and P2 may be fixed or set in advance, and P1 and P2 may be the same or different from each other. In FIG. 7B , it is assumed that P1 = P2 = 160 ms (160 subframes or 160 slots).

On the other hand, although not shown in FIGS. 7A to 7B, when three time resources for S-SSB transmission are set, three offset values can be preset, as in the case where two S-SSB transmission resources are set. , it may not transmit all S-SSBs in the three S-SSB transmission resources.

8 is a diagram illustrating another method of transmitting a sidelink synchronization signal block according to an embodiment of the present disclosure.

7A to 7B illustrate that the S-SSB is transmitted once within the S-SSB transmission period. Alternatively, there may be a case in which the S-SSB is transmitted twice or more within the transmission period of the S-SSB. For example, when transmitting the S-SSB in the hybrid beamforming system, the S-SSB may be transmitted by performing beam sweeping. That is, different S-SSBs may be transmitted in different beam directions. As another example, when the subcarrier spacing increases, the coverage of the S-SSB may decrease because the power density decreases. In this case, the coverage problem can be solved by repeatedly transmitting the S-SSB on the time axis. More specifically, if it is assumed that the S-SSB is transmitted through M frequency blocks, as the subcarrier spacing increases x times, the power density may decrease x times. Accordingly, in this case, the S-SSB may be repeatedly transmitted x times in the time axis.

For the above purpose, FIG. 8 shows a case in which the S-SSB is transmitted four times within the transmission period of the S-SSB. In FIG. 8, S-SSB is transmitted in a slot that is spaced apart by slot N0 from SFN 0 or DFN 0 (ie, offset value = N0). As described above, the sidelink synchronization signal source terminals may start the transmission of the S-SSB in a slot spaced apart from SFN 0 or DFN 0 by slot N0. In this case, the S-SSB may be transmitted K times during a predetermined period, and such K transmission may be performed every S-SSB transmission period. More specifically, as shown in FIG. 8 , in a slot spaced apart by N0 slots from SFN 0 or DFN 0, it may be transmitted 4 times during N2 period (K = 4). In FIG. 8 , N2 is different from N3, but unlike in FIG. 7 , N2 and N3 may have the same value. Although K = 4 is assumed in FIG. 8 , the present invention may not be limited thereto. At least one of the K value and the N2 value may be set from the base station or set in advance, and the S-SSB transmission frequency band and/or the subcarrier spacing used for the S-SSB subcarrier spacing (subcarrier spacing, SCS) may be the same or different.

Meanwhile, the N1 value means an interval with an adjacent S-SSB, and may be the same or different depending on a frequency band through which the S-SSB is transmitted and/or a subcarrier interval used for transmission of the S-SSB. For example, since beam sweeping is not required in frequency band 1 (frequency range, FR1) other than the mmWave band, the value of N1 may be set large. In FR2 including the mmWave band, beam sweeping may be required for coverage extension. In this case, in order to reduce a delay time in a synchronization procedure due to beam sweeping, a small value of N1 may be set.

As another example, sidelink synchronization signal source terminals may be configured for S-SSB transmission through a combination of N0, K, N2, and N3. More specifically, for S-SSB transmission, 15 kHz, 30 kHz, and 60 kHz subcarrier spacing may be used in FR1. In FR2, 60 kHz and 120 kHz subcarrier intervals may be used for S-SSB transmission. In FR1 and FR2, the subcarrier interval that should be used to transmit the S-SSB is related to the frequency at which the sidelink operates, or may be set from the base station through system information and RRC. If there is no base station, a preset value may be used or may be set through PC5-RRC.

In addition to the subcarrier interval, the number of S-SSB transmissions (K) at each subcarrier interval may be set from the base station through system information and RRC. If there is no base station, a preset value may be used or may be set through PC5-RRC. For example, if 15 kHz subcarrier spacing is used in FR1, K = 1 may be used. If 30 kHz subcarrier spacing is used in FR1, K = 1 or 2 may be used. When K = 2 is set, the S-SSB may be repeatedly transmitted twice. If 60 kHz subcarrier spacing is used in FR1, K = 1, 2, or 4. When K = 2, 4 is set, the S-SSB may be repeatedly transmitted 2 times and 4 times, respectively. When a 60 kHz subcarrier spacing is used in FR2, one of K = 1, 2, 4, 8, 16, 32 may be set. As in the above-described examples, when K is greater than 1, it may mean that the S-SSB is repeatedly transmitted as many times as possible. When the 120 kHz subcarrier spacing is used in FR2, one of K = 1, 2, 4, 8, 16, 32, 64 may be set. As in the above-described examples, when K is greater than 1, it may mean that the S-SSB is repeatedly transmitted as many times as possible.

N3 can always be fixed at 160ms. In addition, the N1 value may be set from the base station through system information and RRC. If there is no base station, a preset value may be used or may be set through PC5-RRC.

In FIG. 8 , the S-SSB may be transmitted using the same beam or may be transmitted using different beams. For example, in FIG. 8 , slots #a0, #a1, #a2, #a3 and slots #b0, #b1, #b2, and #b3 show slots in which S-SSBs are transmitted. At this time, S-SSB transmitted in slots #a0, #a1, #a2, and #a3 in FIG. 8 may be different beams, and these different beams are repeated in slots #b0, #b1, #b2, and #b3. may be transmitted (that is, a beam of slot #a0 is transmitted in slot #b0, a beam of slot #a1 is transmitted in slot #b1, etc.). As another example, S-SSBs transmitted in slots #a0, #a1, #a2, and #a3 in FIG. 8 may be the same beam, and the beams transmitted in slots #a0, #a1, #a2, #a3 and Different beams may be used for S-SSB transmission in slots #b0, #b1, #b2, and #b3.

9 is a diagram illustrating an uplink-downlink configuration within a base station coverage according to an embodiment of the present disclosure.

Uplink-downlink configuration of symbols/slots in the 5G communication system may be configured in three steps. First, the uplink-downlink of the symbol/slot may be configured semi-statically through the cell-specific configuration information 910 through the system information in the symbol unit. Specifically, the cell-specific uplink-downlink configuration information through the system information may include uplink-downlink pattern information and reference subcarrier information. Through the uplink-downlink pattern information, the pattern period 903, the number of consecutive downlink slots 911 from the start of each pattern, the number of symbols of the next slot 912, and the number of consecutive uplink slots from the end of the pattern 913 and the number of symbols 914 in the next slot may be indicated. In this case, the UE may determine the slots and symbols not indicated for uplink and downlink as flexible slots/symbols.

Second, the number of consecutive downlink symbols ( 923 and 925) and the number of consecutive uplink symbols 924 and 926 from the end of the slot, or the entire downlink of the slot or the uplink of the entire slot.

Finally, in order to dynamically change downlink signal transmission and uplink signal transmission intervals, symbols indicated by the flexible symbols in each slot (that is, symbols not indicated by downlink and uplink) ), whether each is a downlink symbol, an uplink symbol, or a flexible symbol can be indicated through Slot Format Indicator (SFI) 931 and 932 included in the downlink control channel. .

FIG. 10 shows the number of uplink-downlink symbols occupied by 14 symbols constituting one slot. The slot format indicator of FIG. 9 indicates one index in the format shown in FIG. A format may be selected.

11 is a diagram illustrating a situation in which information is transmitted and received between terminals according to an embodiment.

In FIG. 11 , the sidelink terminal 1102 is in coverage capable of communicating with the base station 1100 , whereas the sidelink terminal 1104 is outside the coverage capable of communicating with the base station 1100 . will be. The sidelink terminal 1102 and the sidelink terminal 1104 are synchronized with the GNSS 1106 signal as mentioned in FIG. 4, or the sidelink terminal 1104 is transmitted by a terminal other than the GNSS 1106. It may be possible to achieve synchronization via a synchronization signal. As shown in FIG. 1B, in FIG. 11, the link between the sidelink terminal 1102 and the base station 1100 is a Uu link composed of an uplink and a downlink, and the link between the terminal 1102 and the terminal 1104 is a sidelink. can be In order for the terminal 1104 to transmit and receive control and data information with other terminals including the terminal 1102, a sidelink synchronization procedure may be performed. To this end, when the terminal 1102 is a terminal transmitting a synchronization signal, it may transmit broadcast information including basic information about the sidelink along with the sidelink synchronization signal. The sidelink broadcast information may be transmitted from the terminal 1102 to the terminal 1104 through a Physical Sidelink Broadcast Channel (PSBCH). The sidelink broadcast information may be referred to as a sidelink master information block (SL-MIB) or other terms such as sidelink system information. As described with reference to FIG. 6, in the sidelink broadcast information, a field indicating a time resource region of S-SSB transmission may be present. The field may be referred to by terms such as TDD-SL-config, TDD-SL-configCommon, or common sidelink resource information. When configuring the S-SSB time resource information, TDD information configured for Uu communication between the base station 1100 and the terminal 1102 (ie, TDD information configured for cellular communication, not sidelink communication) should be considered. For example, when the terminal 1104 performs sidelink transmission during the downlink reception period of the terminal 1102 , the terminal 1102 may deteriorate downlink reception performance due to interference from the terminal 1104 . . On the other hand, when the terminal 1104 performs sidelink transmission in the uplink transmission period of the terminal 1102 (ie, the reception period of the base station 1100), the side of the terminal 1104 received by the base station 1100 The link signal may cause interference in the uplink signal of the terminal 1102 . However, since the terminal 1104 is farther away from the base station 1100 than the terminal 1102, the sidelink signal of the terminal 1104 at the receiving end of the base station 1100 causes interference to the uplink signal of the terminal 1102. The amount can be small. Accordingly, performing sidelink transmission/reception in a resource region configured as at least an uplink transmission interval of Uu may minimize the amount of interference caused by the sidelink to the cellular link. The TDD configuration information for the sidelink may include at least one of the following contents.

- reference subcarrier spacing

- Pattern 1 (transmission period, number of downlink slots, number of downlink symbols, number of uplink slots, number of uplink symbols)

- Pattern 2 (transmission period, number of downlink slots, number of downlink symbols, number of uplink slots, number of uplink symbols)

The pattern 2 may be omitted according to the setting or presetting of the base station. As shown in FIG. 9, one pattern has one specific transmission period, and the number of downlink or uplink or flexible symbols within the transmission period is the number of downlink slots, the number of downlink symbols, the number of uplink slots, and the uplink. It can be determined by the number of symbols. Specifically, the number of first downlink slots in the transmission period means the number of slots configured only with downlink symbols, and the number of downlink symbols means the number of downlink symbols set from before in the slot immediately after the number of slots configured only with downlink symbols. can In addition, the number of last uplink slots in the transmission period means the number of slots configured only with uplink symbols, and the number of uplink symbols means the number of uplink symbols set from the back in a slot immediately before the number of slots configured only with uplink symbols. can In the transmission period, symbols or slots that are not configured as downlink or uplink may be regarded as flexible symbols or flexible slots by the UE. In an area corresponding to the flexible symbol and the flexible slot, uplink or downlink control and data information may be transmitted/received by other higher-order signals or L1 signals. Information necessary to configure the TDD information of the Uu may include reference subcarrier spacing information and information of patterns 1 and 2. The information of pattern 1 and pattern 2 requires the transmission period, the number of uplink/downlink slots and the number of symbols. You will need a bit. The TDD information may be transmitted/received as System Information Bit (SIB) information in the form of PDSCH in Uu.

Common sidelink resource information needs to be configured in consideration of TDD information set in the Uu link, and since it is transmitted/received through PSBCH, high transmission reliability may be required. Therefore, it is necessary to have a number of bits smaller than the number of bits configured to set TDD information in the Uu.

The common sidelink resource information may be configured by at least one of the following methods. In addition, it may be sufficiently possible to configure the common sidelink resource information by some combination of the following methods.

- Method 11-1: It consists of a reference subcarrier interval of 2 bits, a transmission period of 3 bits, and information on the number of sidelink slots of 7 bits, for a total of 12 bits. The reference subcarrier spacing refers to a subcarrier spacing that is a reference for sidelink resource configuration, and candidate values include 15, 30, 60, and 120 kHz. The transmission period means a period in which the sidelink resource configuration is repeated, and indicates one of 0.5, 0.625, 1, 1.25, 2, 2.5, 5, and 10 ms. Here, the 0.625ms value is valid only when the reference subcarrier spacing is 120kHz, the 1.25ms value is valid only when the reference subcarrier spacing is 60 and 120kHz, and the 2.5ms value is valid only when the reference subcarrier spacing is 30, 60, 120kHz do. Alternatively, for each reference subcarrier interval, an indicationable transmission period value may vary. For example, the following [Table 1] is a table showing the transmission period value indicated by each field according to the reference subcarrier interval.

Reference subcarrier spacing Transmission period (3 bits) unit (ms) 000
(Bitmap) 001 010 011 100 101 110 111 15 kHz 0.5 One 2 5 10 30 kHz 0.5 One 2 2.5 5 10 60 kHz 0.5 One 1.25 2 2.5 5 10 120 kHz 0.5 0.625 One 1.25 2 2.5 5 10

The number of sidelink slots means the number of slots configured as sidelinks among all the slots in the indicated transmission period, and the sidelink slots are sequentially located from the last among all the slots in the transmission period. The number of sidelink slots composed of 7 bits may indicate that a maximum of 128 slots will be composed of the number of sidelink slots. Alternatively, the last 2*n or 3*n (or natural number*n) slots within the transmission period may indicate a link used as a sidelink, n is the slot value of the sidelink indicated by the 7 bits, n The natural number value multiplied by n may have different values according to the subcarrier spacing. For example, when the value of the number of sidelink slots is 10 and the total number of slots within the transmission period is 100, the terminal determines that the last 10 slots among 100 slots are configured as sidelink slots. The UE does not expect that the value indicated by the number of sidelink slots composed of 7 bits is set to indicate more than the total number of slots determined by the reference subcarrier interval and the transmission period. In addition, as for the number of sidelink slots configured with the 7 bits, corresponding information may be configured from the least significant bit (LSB). Method 11-1 is characterized in that it has only the slot number information of one specific link (eg, sidelink) in addition to the reference subcarrier interval and transmission period in order to have a size smaller than the TDD information of Uu as described above.

- Method 11-2: It is similar to method 11-1, but is a method of reporting common sidelink resource information in a situation where the base station operates pattern 1 and pattern 2 in Uu. When the Uu informs the TDD information, the base station sets the transmission period of the pattern 1 and the pattern 2 to have the same value. Accordingly, the corresponding transmission period value may be set as the transmission period of common sidelink resource information. For example, if the transmission period of the pattern 1 and the pattern 2 is 10 ms, the transmission period of the common sidelink information is also set to 10 ms. This can be regarded as _{P S} =P ₁ =P _{2 .} P _S is the transmission period of the sidelink, P ₁ is the transmission period of pattern 1, and P ₂ is the transmission period of pattern 2. Also, in Uu, the smallest value among the number of uplink slots for each pattern included in the TDD information may be used as the value of the number of sidelink slots in the common sidelink resource information. For example, when the number of uplink slots of pattern 1 is 10 and the number of uplink slots of pattern 2 is 5, the number of sidelink slots of common sidelink resource information is set to 5. This can be regarded as _{N S} =min(N ₁ ,N _{2 ).} N _S is the number of sidelink slots, N ₁ is the number of uplink slots of pattern 1, and N ₂ is the number of uplink slots of pattern 2.

- Method 11-3: Similar to method 11-1, but information indicated by a 3-bit transmission period in common sidelink resource information is different. Among the 10 values of 0.5, 0.625, 1, 1.25, 2, 2.5, 4, 5, 10, and 20 ms, 8 values excluding 2 values may be configured with the 3-bit transmission period. For example, values of 0.5, 1, 2, 2.5, 4, 5, 10, and 20 ms excluding the values of 0.625 and 1.25 may be indicated as transmission period information in the common sidelink resource information.

- Method 11-4: Similar to method 11-1, but method 11-4 consists of a reference subcarrier interval of 2 bits, a transmission period of 4 bits, and 6 bits of sidelink slot number information, and a total of 12 bits. The reference subcarrier spacing refers to a subcarrier spacing that is a reference for sidelink resource configuration, and candidate values include 15, 30, 60, and 120 kHz. The transmission period means a period in which sidelink resource configuration is repeated, and has one of 0.5, 0.625, 1, 1.25, 2, 2.5, 4, 5, 10, and 20 ms. Here, the 0.625ms value is valid only when the reference subcarrier spacing is 120kHz, the 1.25ms value is valid only when the reference subcarrier spacing is 60 and 120kHz, and the 2.5ms value is valid only when the reference subcarrier spacing is 30, 60, 120kHz do. The number of sidelink slots means the number of slots configured as sidelinks among all the slots in the indicated transmission period, and the sidelink slots are sequentially located from the last among all the slots in the transmission period. The number of sidelink slots composed of 6 bits may indicate that a maximum of 64 slots will be composed of the number of sidelink slots. Alternatively, the last 2*n or 3*n (or natural *n) slots in the transmission period may indicate a link used as a sidelink, n is the slot value of the sidelink indicated by the 6 bits, n The natural number value multiplied by n may have different values according to the subcarrier spacing. For example, in the case of a reference subcarrier interval of 120 kHz, the last 2n slots within the transmission period may be indicated as slots configured as sidelinks, and in this case, a maximum of 128 slots may be indicated as the number of sidelink slots. The terminal does not expect that the value indicated by the number of sidelink slots composed of 6 bits is set to indicate more than the total number of slots determined by the reference subcarrier interval and the transmission period. If this occurs, the terminal considers it an error case. In addition, as for the number of sidelink slots configured with the 6 bits, corresponding information may be configured from the least significant bit (LSB).

- Method 11-5: Similar to Method 11-1, but in Method 11-5, the fields included in the common sidelink resource information are the same as the reference subcarrier interval, the transmission period, and the number of sidelink slots, but the reference subcarrier interval of 2 bits For each, the number of bits of the transmission period and the number of sidelink slots may be different. For example, when the reference subcarrier spacing is 15 kHz and 30 kHz, it consists of a transmission period of 3 bits and 7 bits of sidelink slot number information. When the reference subcarrier spacing is 60 kHz and 120 kHz, a transmission period of 4 bits and 6 bits may be configured with information on the number of sidelink slots of Also, the information period value indicated for each reference subcarrier interval may be different even with the same bit transmission period. For example, the following [Table 2] is a table showing the transmission period value indicated by each field according to the reference subcarrier interval.

Reference subcarrier spacing Transmission period unit (ms) 15 kHz (3 bits) 0.5 One 2 4 5 10 20 30 kHz (3 bits) 0.5 One 2 2.5 4 5 10 20 60 kHz (4 bits) 0.5 One 1.25 2 2.5 4 5 10 20 120 kHz (4 bits) 0.5 0.625 One 1.25 2 2.5 4 5 10 20

Alternatively, if the reference subcarrier spacing is 15 kHz and 30 kHz, the values indicated by the 3-bit transmission period are 0.5, 1, 2, 2.5, 4, 5, 10, 20, and 2.5 can be regarded as a valid indication only for 30 kHz. . In addition, when the reference subcarrier spacing is 60 kHz and 120 kHz, the values indicated by the 4-bit transmission period are 0.5, 0.625, 1, 1.25, 2, 2.5, 4, 5, 10, 20, and 0.625 is a valid indication only for 120 kHz. can be considered The number of sidelink slots (x*n) is information indicating that the last x*n of slots in the transmission period are slots to be configured as sidelinks. or may have the same value irrespective of the subcarrier spacing, and n is a value indicated by the number of sidelink slots field in common sidelink resource information.

- Method 11-6: Similar to Method 11-1 or Method 11-5, Method 11-6 has the same information on subcarrier interval, transmission period, and number of sidelink slots based on fields included in common sidelink resource information, For each bit reference subcarrier interval, the transmission period is the same as all 4 bits, but the number of bits in the number of sidelink slots may be different. For example, when the reference subcarrier spacing is 15 kHz and 30 kHz, it consists of 6 bits of sidelink slot number and 2 bits of reserved bit information, and when the reference subcarrier spacing is 120 kHz, 7 bits of sidelink slot number , may be composed of 1-bit reserved bit information. The reserved bit is not a field included in the common sidelink resource information, but may be configured as one of information fields in a PSBCH in which the common sidelink resource information is transmitted and received, and is a field that can be utilized for future services.

- Method 11-7: Method 11-7 is a generalized method of methods 11-1 to 11-6 described above. The common sidelink information has a k-bit value, and is configured in a form having x-bit reference subcarrier interval, y-bit transmission period, and z-bit sidelink slot number information. Some of y and z may have different values according to a reference subcarrier spacing value. k=x+y+z. The y bit is determined in consideration of the _{number of transmission periods (T i} ) that can be supported in a specific subcarrier interval (i). It can be determined through _{y i} =ceiling(log ₂ (T _{i )).} y included in the common sidelink has a different bit value for each reference subcarrier interval, or the maximum value (max(y ₁ , y ₂ , ..., y _i ) _{among y i calculated through some or all subcarrier intervals} It may also be possible to use the z bit is determined by considering the maximum number of sidelink slots (Ni) that can be supported in a specific subcarrier interval (i) z _i =ceiling(log ₂ (N _i )) to be determined can. z is the maximum value _{(max (z 1, z 2} , z _i in the calculation by the reference sub-carrier interval for each of the different bit values, or some or all of the sub-carrier interval to be included in the common side links ..., It _{may also be possible to use z i} ) The number of sidelink slots indicated through the z bit value (N _i ) may be composed of Ni=m*b, and m is a natural number value, equal to or according to the subcarrier spacing. It may be another value, and b is a value indicated through the z bit The number of sidelink slots means the last number of slots configured as a sidelink among slots in the transmission period.

- Method 11-8: Method 11-8 is similar to the above-mentioned methods, but the common sidelink information has a k-bit value, a reference subcarrier interval of x bits, a transmission period of y bits, and a sidelink slot of z bits It is composed of a form with number information, and z bits have a form composed _{of z a} bits and z _{b bits.} z=z _a +z _b . The z _a bit is information indicating granularity information of slots used for sidelinks, and the z _b bit is a value indicating the number of sidelink slots. In other words, the number of sidelink slots (N _i ) is determined by Ni=m*b, where the values of m and b may be determined by _{z a} bits and z _{b bits, respectively.} For example, if it is 120 kHz and the transmission period is 20 ms, a total of 160 slots will exist within the indicated transmission period, and when the sidelink slots are indicated in units of one slot, a total of 8 bits will be required. However, when 8 bits or less are required due to the information size constraint of the PSBCH, if the sidelink can be indicated in units of 4 slots, only a total of 40 slots unit needs to be indicated, so a total of 6 bits may be required. The _{bit sizes of z a} and z _b may be different or the same for each subcarrier interval, and the range of information indicated by each bit may also be different or the same for each subcarrier interval. Alternatively, a method of notifying the transmission period and the number of sidelink slots in one field, unlike Method 11-8, may be sufficiently considered. That is, information on the transmission period and the last number of slots used for sidelink communication within the transmission period is informed through one value of a specific field.

12 is a diagram illustrating a type of a link through which a sidelink terminal may perform sidelink communication according to an embodiment of the present disclosure.

More specifically, sidelink communication may be performed through at least one of the following links.

- A link between an NR sidelink terminal and another NR sidelink terminal may be referred to as an NR sidelink. The NR sidelink terminal may transmit sidelink control information and data information for NR sidelink communication to another NR sidelink terminal through the NR sidelink. In addition, the NR sidelink terminal may receive sidelink control information and data information for NR sidelink communication through the NR sidelink from another NR sidelink terminal.

- A link between the NR sidelink terminal and the LTE sidelink terminal may be referred to as an LTE sidelink. In this case, it may be assumed that the NR sidelink terminal has the capability to support LTE sidelink communication. Such an NR sidelink terminal may transmit/receive control information and data information for LTE sidelink communication through the LTE sidelink.

- The downlink or uplink between the NR sidelink terminal and the NR base station (gNB) may be referred to as NR Uu.

* The NR sidelink terminal may receive control information and data information on NR sidelink transmission and reception from an NR base station (gNB) through NR Uu. In addition, the NR sidelink terminal may transmit NR sidelink control information and data information received from another NR sidelink terminal to the gNB through the NR Uu.

* The NR sidelink terminal may receive control information and data information related to LTE sidelink transmission and reception from an NR base station (gNB) through the NR Uu. In addition, the NR sidelink terminal may transmit LTE sidelink control information and data information received from the LTE sidelink terminal to the gNB through the NR Uu. In this case, it may be assumed that the NR sidelink terminal has the capability to support LTE sidelink communication.

- The downlink or uplink between the NR sidelink terminal and the LTE base station (eNB) may be referred to as LTE Uu.

* The NR sidelink terminal may receive control information and data information related to NR sidelink transmission and reception from an LTE base station (eNB) through LTE Uu. In addition, the NR sidelink terminal may transmit NR sidelink control information and data information received from another NR sidelink terminal to the eNB through LTE Uu. In this case, it may be assumed that the NR sidelink terminal has the capability to support LTE Uu.

* The NR sidelink terminal may receive control information and data information related to LTE sidelink transmission and reception from the eNB through LTE Uu. In addition, the NR sidelink terminal may transmit the LTE sidelink control information and data information received from the LTE sidelink terminal to the eNB through the LTE Uu. In this case, it can be assumed that the NR sidelink terminal has the capability to support LTE sidelink communication and also has the capability to support LTE Uu.

13 is a diagram illustrating a sidelink synchronization procedure according to an embodiment of the present disclosure.

More specifically, in FIG. 13 , NR V2X UE-1 and LTE V2X UE-1 exist within the coverage of the eNB, and NR V2X UE-2 and LTE V2X UE-2 exist outside the coverage of the eNB. Since NR V2X UE-1 and LTE V2X UE-1 exist within the coverage of the eNB, it is possible to detect and receive LTE PSS/SSS transmitted from the eNB, and NR V2X UE-2 and LTE V2X UE-2 are the eNB's Since it exists out of coverage, it is a case in which LTE PSS/SSS transmitted from the eNB cannot be detected and received. In FIG. 13 , it may be assumed that the NR V2X UE-1 within the eNB coverage has selected the eNB as the synchronization signal source according to the rule mentioned in FIG. 4 . And in FIG. 13, NR V2X UE-1 has shown that it has the ability to transmit both NR S-SSB and LTE SLSS, but is not limited thereto. That is, the NR V2X UE-1 may have the ability to transmit only the NR S-SSB without the transmission capability of the LTE SLSS.

In the following examples, NR V2X UE-1 existing within the coverage of the eNB selects the eNB as a synchronization signal source, which means that NR V2X terminals have the ability to detect LTE PSS / SSS, which is the synchronization signal of the eNB. It may mean (Alt1). As another example, the NR V2X UE-1 that selects the eNB as the synchronization signal source may mean that it has the ability to detect the LTE PSS/SSS transmitted by the eNB and decode the LTE PBCH (Alt2). As another example, the NR V2X UE-1 that selects the eNB as the synchronization signal source can detect the LTE PSS/SSS transmitted by the eNB and decode the LTE PBCH, and furthermore, the LTE V2X SIB information set for the LTE V2X terminal. It may mean that it can be decoded (Alt3). As another example, the NR V2X UE-1 that selects the eNB as the synchronization signal source may detect the LTE PSS/SSS transmitted by the eNB and decode the LTE PBCH, and the NR V2X SIB configured for the NR V2X terminal within the eNB coverage. It may mean that information can be decoded (Alt4). Alternatively, it may mean a terminal capable of both Alt3 and Alt4.

Under these various assumptions, the NR V2X terminal within the eNB coverage may transmit the NR S-SSB for the sidelink terminal located outside the eNB coverage. In this case, the PSBCH constituting the NR S-SSB may include the information described in FIGS. 6 to 11 . More specifically, it may include at least one of the frame number, downlink and uplink configuration information, slot index, and coverage indicators mentioned in FIG. 6 . In this case, the downlink and uplink configuration information may be set through one of the methods mentioned in FIG. 11 .

Since the NR V2X UE-1 of FIG. 13 is within the coverage of the eNB, the NR V2X UE-1 may set the coverage indicator field of the PSBCH to '1'. As another example, although the NR V2X UE-1 is in the coverage of the eNB, since it is transmitting the NR S-SSB, from the viewpoint of the NR sidelink, the NR V2X UE-1 may be regarded as being located outside the coverage of the base station. Therefore, in this case, the NR V2X UE-1 may set the coverage indicator field of the PSBCH to '0'. More specifically, if the frequency of the NR sidelink in which the Uu of the eNB and the NR V2X UE-1 operates is the same, the NR V2X UE-1 is considered to be within the coverage of the base station, and the coverage indicator field of the PSBCH is set to '1'. can be set to On the other hand, if the frequency of the NR sidelink in which the Uu of the eNB and the NR V2X UE-1 operates is different, the NR V2X UE-1 is considered to be out of the coverage of the base station, and the coverage indicator field of the PSBCH is set to '0'. can be set.

In FIG. 13 , the NR S-SSB transmitted by the NR V2X UE-1 within the coverage of the eNB is for performing a sidelink synchronization operation of the NR sidelink terminal located outside the coverage of the eNB. As mentioned in FIG. 4, the NR sidelink terminal may select an NR base station (gNB) and an LTE base station (eNB) as a sidelink synchronization signal source. On the other hand, since NR V2X UE-1 is within the coverage of the gNB as described in FIG. 6, sidelink terminals located outside the coverage of the gNB In order to minimize the interference caused to the cellular terminal or the sidelink terminal located in the gNB coverage, NR V2X UE-1 may transmit uplink-downlink configuration information through PSBCH. However, when the carrier frequency at which Uu operates and the frequency at which the NR sidelink operates are different from each other, it may not be necessary to consider the interference problem. In this case, since the uplink-downlink configuration information included in the PSBCH is unnecessary, it may be omitted, set not to be used (ie, none), or set to a specific value (eg, uplink-downlink configuration information). all bits representing '0' or set to '1'). On the other hand, when the carrier frequency at which Uu operates and the frequency at which the NR sidelink operates are the same, it is necessary to consider the interference problem.

In this case, as described with reference to FIG. 6 , uplink-downlink configuration information composed of 12 bits or 13 bits may be included in the PSBCH.

14 is another diagram illustrating a sidelink synchronization procedure according to an embodiment of the present disclosure.

More specifically, in FIG. 14 , NR V2X UE-1 and NR V2X UE-2 exist within the coverage of the gNB, and NR V2X UE and LTE V2X UE exist outside the coverage of the gNB. Because NR V2X UE-1 and NR V2X UE-2 are within the coverage of the gNB, they can detect and receive the NR SSB transmitted from the gNB, and since the NR V2X UE and the LTE V2X UE are outside the coverage of the gNB, This is a case where the NR SSB transmitted from the gNB cannot be detected and received (and the LTE V2X UE cannot detect and receive the NR SSB even if it is within the coverage of the gNB). In FIG. 14 , it may be assumed that NR V2X UE-1 and NR V2X UE-2 within gNB coverage have selected gNB as a synchronization signal source according to the rule mentioned in FIG. 4 . And in FIG. 14 , the NR V2X UE-1 has shown that it has the ability to transmit both the NR S-SSB and the LTE SLSS, but is not limited thereto. That is, the NR V2X UE-1 may have the ability to transmit only the NR S-SSB without the transmission capability of the LTE SLSS.

13 illustrates that the NR sidelink terminal exists in the coverage of the eNB and intends to transmit the NR S-SSB within the coverage of the eNB. Alternatively, in FIG. 14 , the NR sidelink terminal exists in the coverage of the gNB and attempts to transmit LTE SLSS within the coverage of the gNB. The subcarrier spacing used for LTE SLSS transmission is always fixed at 15 kHz, which may be different from the subcarrier spacing used for NR S-SSB transmission. Therefore, when NR V2X UE-1 transmits LTE SLSS within gNB coverage, if NR Uu and LTE sidelink operate on the same carrier frequency, a terminal performing NR sidelink communication within gNB coverage and NR cellular communication are performed. It may cause interference to the terminal. Alternatively, if the NR Uu and LTE sidelinks operate on different carrier frequencies, the interference problem may not need to be considered.

Under these various assumptions, an NR sidelink terminal within gNB coverage (an NR sidelink terminal supporting LTE sidelink) may transmit LTE SLSS for LTE sidelink terminals located outside the gNB coverage. In this case, the PSBCH constituting the LTE SLSS may include the information mentioned in FIG. 6 . More specifically, it may include at least one of the frame number, downlink and uplink configuration information, slot index, and coverage indicators mentioned in FIG. 6 . In this case, since LTE SLSS uses only the 15 kHz subcarrier interval, the slot index may have the same meaning as the subframe index as described in FIG. 6 .

Since the NR V2X UE-1 of FIG. 14 is within the coverage of the gNB, the NR V2X UE-1 may set the coverage indicator field of the PSBCH to '1'. As another example, although the NR V2X UE-1 is in the coverage of the gNB, since it is transmitting LTE SLSS, from the LTE sidelink point of view, the NR V2X UE-1 may be regarded as being located outside the coverage of the base station. Therefore, in this case, the NR V2X UE-1 may set the coverage indicator field of the PSBCH to '0'. More specifically, when the frequency of the LTE sidelink in which Uu of the gNB and NR V2X UE-1 operates is the same, the NR V2X UE-1 is considered to be within the coverage of the base station, and the coverage indicator field of the PSBCH is set to '1'. can be set to On the other hand, if Uu of the gNB and the LTE sidelink frequency in which NR V2X UE-1 operates are different, the NR V2X UE-1 is considered to be out of the coverage of the base station, and the coverage indicator field of the PSBCH is set to '0'. can be set.

In FIG. 13 , the NR S-SSB transmitted by the NR V2X UE-1 within the coverage of the eNB is for performing a sidelink synchronization operation of the NR sidelink terminal located outside the coverage of the eNB. As mentioned in FIG. 4, the NR sidelink terminal may select an NR base station (gNB) and an LTE base station (eNB) as a sidelink synchronization signal source. However, in FIG. 14 , the LTE SLSS transmitted by the NR V2X UE-1 within the coverage of the gNB is for performing a sidelink synchronization operation of the LTE sidelink terminal located outside the coverage of the gNB. Since the LTE sidelink terminal cannot select the gNB as the sidelink synchronization signal source, the NR V2X UE-1 is independent of whether the carrier frequency on which Uu operates is the same as or different from the carrier frequency on which the LTE sidelink operates, in Fig. In the scenario of 14, the coverage indicator of the PSBCH may always be set to '0'.

On the other hand, since NR V2X UE-1 is within the coverage of the gNB as described in FIG. 6, sidelink terminals located outside the coverage of the gNB In order to minimize the interference caused to the cellular terminal or the sidelink terminal located in the gNB coverage, NR V2X UE-1 may transmit uplink-downlink configuration information through PSBCH. However, when the carrier frequency at which the NR Uu operates and the frequency at which the LTE sidelink operates are different from each other, it may not be necessary to consider the interference problem. In this case, since the uplink-downlink configuration information included in the PSBCH is unnecessary, it may be omitted, set not to be used (ie, none), or set to a specific value (eg, uplink-downlink configuration information). all bits representing '0' or set to '1'). On the other hand, when the carrier frequency at which the NR Uu operates and the frequency at which the LTE sidelink operates are the same, it is necessary to consider the interference problem.

Since the LTE sidelink operates in an intelligent transport system (ITS) dedicated frequency band, it may be different from the frequency band of NR Uu. And the PSBCH transmitted by the NR V2X UE-1 located within the coverage of the gNB is to support the synchronization procedure of the LTE sidelink terminal. As mentioned above, since the LTE sidelink terminal does not consider the gNB as a sidelink signal source, in the scenario of FIG. 14 , NR V2X UE-1 is located in the base station coverage, but NR V2X UE-1 indicates the coverage indicator ' It is set to 0', and the PSBCH may include uplink-downlink configuration information composed of 3 bits, similar to the PSBCH of the conventional LTE sidelink. In this case, the uplink-downlink configuration information included in the PSBCH transmitted by the NR V2X UE-1 may be set to 'none'.

15 is a diagram illustrating the structure of a terminal according to an embodiment of the present invention.

Referring to FIG. 15 , the terminal may include a transceiver, a terminal control unit, and a storage unit. In the present invention, the terminal control unit may be defined as a circuit or an application-specific integrated circuit or at least one processor.

The transceiver may transmit/receive signals to and from other network entities. The transceiver may receive, for example, system information from a base station, and may receive a synchronization signal or a reference signal.

The terminal control unit may control the overall operation of the terminal according to the embodiment proposed in the present invention. For example, the terminal control unit may control the signal flow between blocks to perform an operation according to the above-described drawings and flowcharts. Specifically, the terminal control unit operates according to a control signal from the base station and may send and receive messages or signals with other terminals and/or base stations.

The storage unit may store at least one of information transmitted and received through the transceiver and information generated through the terminal control unit.

16 is a diagram illustrating a structure of a base station according to an embodiment of the present invention.

Referring to FIG. 16 , a base station may include a transceiver, a base station control unit, and a storage unit. In the present invention, the base station control unit may be defined as a circuit or an application specific integrated circuit or at least one processor.

The transceiver may transmit/receive signals to and from other network entities. The transceiver may transmit, for example, system information to the terminal, and may transmit a synchronization signal or a reference signal.

The base station controller may control the overall operation of the base station according to the embodiment proposed in the present invention. For example, the base station controller may control operations proposed in the present invention to manage and reduce interference with a neighboring base station. Specifically, the base station control unit may transmit a control signal to the terminal to control the operation of the terminal, or may exchange messages or signals with the terminal.

The storage unit may store at least one of information transmitted/received through the transceiver and information generated through the base station control unit.

17 is a diagram illustrating a method of setting sidelink resource information according to an embodiment of the present disclosure.

Referring to FIG. 17 by taking FIG. 11 as an example, the sidelink terminal 1104 receives sidelink resource information from the sidelink terminal 1102 through the PSBCH. Specifically, the sidelink resource information may include TDD configuration information used for uplink and downlink communication within the coverage of the base station 1100 . The TDD configuration information may mean at least one or a combination of two or more of the following fields.

One. A field indicating a transmission period: means a field indicating a period of a resource (eg, an uplink slot) for uplink transmission of terminals located in the base station 1100 operating in TDD, and the fields include 0.5, 0.625 , 1, 1.25, 2, 2.5, 4, 5, 10, 20 ms may be included, or some values may be included. As another example, other than the above values, integer values that can divide 20 ms without a remainder may be included, and the minimum value of the integer value may be 0.5 ms. In addition, the value indicating the transmission period may vary according to the subcarrier interval. For example, when the transmission period is set based on the subcarrier interval of 15 kHz, the transmitting terminal can sufficiently inform which value among 0.5, 1, 2, 4, 5, 10, and 20 ms is set as the transmission period with 3 bits. The subcarrier spacing of 15 kHz may always be applied as a fixed value regardless of the subcarrier spacing of the S-SSB. In addition, 15 kHz is only an example, and other subcarrier spacings may be always applied as fixed values, and it may be possible for FR1 and FR2 to have different fixed subcarrier spacing values. The transmission period may be regarded as a value of T.

2. Field indicating transmission period pattern information: A corresponding field may or may not exist in the PSBCH according to the subcarrier interval. When the corresponding field is present in the PSBCH, it may have 1 bit of information. It is a value indicating whether the transmission period value set in the transmission period is a value having one transmission period or a transmission period in which two transmission periods having equal lengths are combined. For example, when the transmission period value in the transmission period field is informed as 10 ms, the information in the transmission period pattern field 1 bit indicates whether the value has one transmission period in units of 10 ms, or two transmission units in units of 5 ms can tell you if it is the sum of Alternatively, it is also possible to inform whether the transmission period value set in the transmission period is a value having one transmission period or whether the transmission period value set in the transmission period is a value indicating one transmission period among two consecutive transmission periods. can For example, when the transmission period value in the transmission period field is informed as 10ms, as information of 1-bit of the transmission period pattern field, whether the corresponding value has one transmission period in units of 10ms, or in a form in which the units of 10ms are repeated twice This is a value indicating whether the actual transmission period is repeated in units of 20ms. In summary, the transmission period pattern field can be used to inform whether one transmission period or two transmission periods are combined. When the transmission period value indicated in the transmission period field is T, the method described above is T=T1+T2, meaning T1=T2. And the method described in the latter means T+T=T0.

3. Field indicating the number of sidelink slots: This is a field indicating information on the number of slots for sidelink communication within the transmission period set by the transmission period and transmission period pattern field. Specifically, the number of sidelink slots indicates the number of sidelink slots from the last slot among all slots included within the transmission period indicated by the transmission period field and the transmission period pattern. For example, when a total of 100 slots are determined by the transmission period field and the transmission period pattern and 10 slots are determined as sidelinks by the number of sidelink slots field, the terminal selects the last 10 slots among 100 slots. It is determined as a slot used for sidelink communication. Also, a method of interpreting a field indicating the number of sidelink slots may vary according to the transmission period pattern. For example, when two transmission periods are combined by the sidelink transmission period and the pattern, some of the fields indicating the number of sidelink slots are for sidelink communication among all slots included in the first transmission period. The number of slots may be notified, and the remainder may be utilized for the purpose of notifying the number of slots for sidelink communication among all slots included in the second transmission period. In summary, a method of interpreting a field indicating the number of sidelink slots may vary depending on whether there is one or two transmission periods determined by the transmission period and the transmission period pattern. The size of the corresponding field may have a value of 8 bits or other bits.

For example, when information indicating a sidelink resource among information included in the above-described PSBCH is 12 bits, the following method may be possible. A field indicating a 3-bit transmission period, a field indicating a 1-bit transmission period pattern, and an 8-bit field indicating the number of sidelink slots. In addition, the information indicating the sidelink resource assumes that a reference subcarrier interval is 15 kHz. The values of the transmission period that the 3-bit transmission period field can inform may be all or some values among 0.5, 1, 2, 4, 5, 10, and 20 ms. The 1-bit transmission period pattern indicates whether the value of the transmission period is a unit of one transmission period or a unit of adding two transmission periods. That is, it indicates whether there are two transmission periods in which only one transmission period exists according to the transmission period pattern. When only one transmission period is indicated, the entire field indicating the number of 8-bit sidelink slots informs information on the number of slots used as sidelinks within the corresponding transmission period. Alternatively, in the case of 15 kHz, when the maximum transmission period is 20 ms, since there are only 20 slots in total, it is possible that only 5 bits of the LSB inform the number of sidelink slots and the remaining MSB bits have a fixed value of 0 or 1. can If there are two transmission periods, the field indicating the number of 8-bit sidelink slots is divided into two fields. MBS 4 bits indicate the number of sidelink slots among all slots in the first transmission period, and 4 LSB bits indicate the number of sidelink slots among all slots in the second transmission period. For example, when it is indicated that the transmission period is 20 ms and the transmission period pattern has two transmission periods, it may be possible for the first transmission period and the second transmission period to have a length of 10 ms, respectively. That is, the sum of the first transmission period and the second transmission period becomes the value indicated by the transmission period. Alternatively, when it is indicated that the transmission period is 10 ms and the transmission period pattern has two transmission periods, it may be possible for the first transmission period and the second transmission period to have a length of 10 ms, respectively. That is, the first transmission period and the second transmission period are the same as the values indicated in the transmission period. In the first and second transmission periods by the above methods, the first 4 bits of the field 8 bits indicating the number of sidelink slots informs the number of sidelink slots in the transmission period of the first 10 ms, and the second 4 bits are In the second transmission period of 10 ms, information on the number of sidelink slots is reported. Accordingly, the terminal may be able to receive different information on the number of sidelink slots for the first transmission period and the second transmission period.

One slot in the 15 kHz subcarrier spacing will have the same length of time as 2 slots in the 30 kHz subcarrier spacing, 4 slots in the 60 kHz subcarrier spacing, and 8 slots in the 120 kHz subcarrier spacing. Therefore, when the UE synchronizes the SSB at a subcarrier interval other than 15 kHz and then performs communication at the corresponding subcarrier interval for sidelink communication, the UE transmits the indicated sidelink resource information based on the 15 kHz subcarrier interval to the corresponding UE Sidelink communication is performed by reinterpreting the synchronized subcarrier interval as sidelink resource information. In other words, when a specific slot is configured as a sidelink resource through the sidelink resource information indicated based on the 15 kHz subcarrier interval, the terminal determines the corresponding slot and at least one symbol (or all symbols in the slot) from the time resource viewpoint. A partially overlapping slot is determined as a resource region configured for sidelink communication. Although it is assumed that the reference subcarrier spacing of the information indicating the sidelink resource is 15 kHz, other subcarrier spacing values may be used, and it may be possible that FR1 and FR2 have the same or different reference subcarrier spacing values.

The field indicating the transmission period and the field indicating the transmission period pattern may consist of separate bit fields, or as one bit field, one bit value may inform both the transmission period and the transmission period pattern at the same time. The two transmission periods P1 and P2 described above in FIG. 17 are determined by a field indicating a transmission period and a field indicating a transmission period pattern. P1+P2 should be a value that divides 20ms without remainder. Alternatively, only one value of one transmission period P1 or P2 among the two transmission periods P1 and P2 described above in FIG. 17 is determined by the field indicating the transmission period and the field indicating the transmission period pattern. For example, the following Table 3 shows information about this as an example.

index P1 P2 One 0.5 ms 0.5 ms 2 1 ms 1 ms 3 0.5 ms 2 ms 4 ... ...

In Table 3, the transmission period of P1 and P2 may be indicated by the transmission period field, and the transmission period pattern may indicate whether only the P1 value or the P1 and P2 values are used together. Alternatively, as shown in Table 4, if the value indicated by a specific index has only one value of P1, it is determined as a pattern considering only one transmission period, and if the value indicated by another specific index includes the values of P1 and P2, two transmission periods is considered as the considered pattern. For example, in Table 4, when the index indicates 3, the terminal determines that the 0.5 ms transmission cycle unit is repeated, whereas when the index indicates 2, the first transmission period of 0.5 ms and the second transmission of 0.5 ms The terminal determines that the period is repeated in units of the combined transmission period.

index P1 P2 One 0.5 ms 0.5 ms 2 1 ms 1 ms 3 0.5 ms 4 ... ...

The bit field indicating the number of sidelink slots is a field indicating how many of the actual number of sidelink slots are included among the slots within the set transmission period as described above. The number of slots is determined by a set transmission period and subcarrier interval, the transmission period is indicated by the above-described transmission period field, and the subcarrier interval may follow a sidelink synchronization signal or a value defined in a standard. The subcarrier spacing may have a different value or the same value according to FR1 and FR2 when the value defined in the standard is followed. If the bit field indicating the number of sidelink slots is N bits, and the total number of slots within the transmission period indicated by the corresponding bit field is K, the granularity indicated by the bit field indicating the number of sidelink slots is ceiling(K/K/ 2 ^N ) or floor(K/2 ^N ) or round(K/2 ^N ) or max(floor(K/2 ^N ),1) or a combination thereof. For example, if the total number of slots in a specific transmission period is 40 and the size of the bit field indicating the corresponding period is 4 bits, max(floor(40/16),1)=2 It will tell you the number of slots. That is, it may be possible to indicate that one of the 16 values, 2, 4, 6, 8, ..., 32 values from the back of the transmission period, respectively, is the value of the number of slots used as the sidelink. . When the bit field indicating the number of sidelink slots indicates two transmission periods, they are indicated by different bit fields, and the size of each bit field may be the same or different according to the set transmission period.

Or, for example, as shown in Table 5, indicating the number of uplink slots (or the number of slots that can be used for sidelink resources) to the terminal based on the transmission period, the transmission period pattern, and the total number of slots in a specific transmission period. it may be possible As 4-bit information providing transmission period information, one index value among indices 1 to 16 of Table 5 is indicated, and transmission period information (P1, P2) is provided. As 1-bit information that provides transmission pattern information, either one of transmission period pattern 1 (P1) and transmission period pattern 2 (P2) is used, or both transmission period pattern 1 (P1) and transmission period pattern 2 (P2) are used. tells you what to do When only one of the transmission period pattern 1 and the transmission period pattern 2 is used, it is possible to instruct the standard to use only one specific pattern or to determine one specific value by another higher-order signal. In [Table 5], μ is a code that provides subcarrier spacing information, μ=1 is 15kHz, μ=2 is 30kHz, μ=3 is 60kHz, μ=4 is 120kHz, μ=5 is 240kHz, To generalize this, it has a subcarrier spacing of ^{15*2 μ kHz according to the μ value.} With 1-bit and 4-bit information, the UE includes information on the total number of slots within a specific transmission period according to whether one or a plurality of transmission periods are included in the unit of the transmission period indicating the UL slot number information and the subcarrier interval (S1, S2) can be identified by the terminal. When only S1 or S2 is informed, 8 bits indicate whether 2^8 slots from the back among the total slots of the S1 or S2 transmission period are allocated as uplink slots. When S1 and S2 are informed, information on whether 2^N1 slots and 2^N2 slots are allocated as uplink slots from the rear among the total slots in the S1 and S2 transmission periods, respectively, with N1 bits and N2 bits. The sum of N1 and N2 is 8 bits. In the following [Table 5], an index containing 0.625ms is valid only at μ=3, an index containing 1.25ms is valid only at μ=2 or 3, and an index containing 2.5ms is valid only at μ=1, 2, 3 valid only in In summary, the TDD configuration information of the sidelink may be determined as 1 + 4 + 8 = 13 bits. Alternatively, it may be determined as 4 + 8 = 12 bits except for bit information indicating a 1-bit transmission period pattern, and in this case, it is assumed that two transmission period patterns (P1, P2) are always notified to the UE. In this case, if the actual Uu has one transmission period pattern, even if two transmission period patterns are indicated by default through PSBCH, the transmission period and the number of uplink slots within the transmission period are always set to the same values as if one transmission period You will be able to operate as directed.

Index Transmission period 1 (P1) ms Transmission period 2 (P2) ms Total number of slots (S1) for 15*2 ^μ kHz Total number of slots (S2) for 15*2 ^μ kHz One 0.5 0.5 0.5*2 ^μ 0.5*2 ^μ 2 0.625 0.625 0.625*2 ^μ 0.625*2 ^μ 3 One One 1*2 ^μ 1*2 ^μ 4 0.5 2 0.5*2 ^μ 2*2 ^μ 5 2 0.5 2*2 ^μ 0.5*2 ^μ 6 1.25 1.25 1.25*2 ^μ 1.25*2 ^μ 7 One 3 1*2 ^μ 3*2 ^μ 8 3 One 3*2 ^μ 1*2 ^μ 9 2 2 2*2 ^μ 2*2 ^μ 10 One 4 1*2 ^μ 4*2 ^μ 11 4 One 4*2 ^μ 1*2 ^μ 12 2 3 2*2 ^μ 3*2 ^μ 13 3 2 3*2 ^μ 2*2 ^μ 14 2.5 2.5 2.5*2 ^μ 2.5*2 ^μ 15 5 5 5*2 ^μ 5*2 ^μ 16 10 10 10*2 ^μ 10*2 ^μ

In the case of 0.5 ms and μ=0, since it has a transmission period in units of 7 symbols, the UE does not regard it as valid information and may treat it as an error case. Alternatively, when 0.5 ms and μ=0, the UE may always determine that all resources are configured as uplink resources. The μ value is obtained through a sidelink synchronization signal or a common or separate value is applied to FR1 and FR2 according to the 3GPP standard, and the UE may always consider it to be fixed. In a situation in which the μ value has a fixed value for each FR1 and FR2, the UE may have a different value from the μ obtained from the sidelink synchronization signal. For example, in [Table 5], in a situation where 60 kHz is defined, it may be possible for the terminal to obtain a synchronization signal of 15 kHz. Therefore, when the terminal provides slot information at a subcarrier interval of 60 kHz in a situation where the sidelink slot unit is regarded as a 15 kHz sub-carrier interval, the UE provides all slots with a sub-carrier interval of 60 kHz included in the slot based on the 15 kHz sub-carrier interval. Only when the uplink is set, the slot based on the 15 kHz subcarrier interval is determined as the uplink slot. In other words, the slots based on the 15 kHz subcarrier spacing will include a total of four 60 kHz subcarrier spacing, and if at least one of the four 60 kHz subcarrier spacing based slots indicates a slot other than the uplink, The UE determines that the slot based on the 15 kHz subcarrier interval is not the uplink. When the bit field indicating the number of sidelink slots (or the number of uplink slots) included in each transmission period is N bits, and the total number of slots in the transmission period indicated by the bit field is K, the sidelink slot The granularity indicated by the bit field indicating the number is at least one of ceiling(K/2 ^N ) or floor(K/2 ^N ) or round(K/2 ^N ) or max(floor(K/2 ^N ),1) or a combination thereof.

18 is a diagram illustrating a method of setting sidelink resource information according to an embodiment of the present disclosure.

Among the PSBCH fields, TDD configuration information is used to provide the terminal with slot information for transmitting and receiving sidelink data. Specifically, the UE may inform the UE of an uplink slot (UL slot) using a sidelink resource based on TDD common information that the eNB operates in Uu. The corresponding TDD configuration information is divided into the following detailed elements. The subcarrier spacing indicated in the TDD configuration information may be obtained from a synchronization signal, or a reference subcarrier spacing value may be determined by a specific frequency or transmission period, or may be determined by other common higher-order signals or L1 signals, or PSBCH It can be determined by other field information of For example, when the subcarrier interval obtained by the terminal through the sidelink synchronization signal is 15 kHz, the terminal considers that the TDD configuration information is set based on 15 kHz. As another example, as described above in FIG. 17, the subcarrier spacing (or μ value) is obtained through a sidelink synchronization signal or a common or separate value is applied to FR1 and FR2 according to the 3GPP standard, so that the terminal is always fixed. can be considered In a situation where the μ value has a fixed value for each FR1 and FR2, the UE may have a different value from the μ obtained from the sidelink synchronization signal. As another example, the subcarrier spacing and cyclic prefix used in the sidelink synchronization signal are preset or defined by frequency bands, regions, resource pools, or a combination thereof. use. For example, when the terminal uses frequency B in region A, it may be possible to perform access with a normal cyclic prefix and a subcarrier interval of 15 kHz.

- Transmission period pattern number indicator: As information indicating the number of transmission period patterns, in FIG. 18 , it indicates whether the corresponding transmission period pattern is one pattern 1800 or two patterns 1802 . One pattern indicates the number of UL slots (S1) in one transmission period (P1), and two patterns indicate the number of UL slots (S1, S2) in two separate transmission periods (P1, P2), respectively. For example, the corresponding transmission period pattern number indicator may be composed of 1 bit.

- Transmission period indicator: Information indicating one or two transmission periods by the number indicator of the number of transmission period patterns. For example, through Table 6, it may be possible to inform the transmission period according to the number of transmission period patterns. As another example, it may be possible to indicate the transmission period as shown in Table 6 according to the number of transmission period patterns with a 4-bit transmission period indicator.

1 transmission cycle pattern 2 transmission cycle patterns Index Transmission period 1 (P1) ms Transmission period 1 (P1) ms Transmission period 2 (P2) ms One 0.5 0.5 0.5 2 0.625 0.625 0.625 3 One One One 4 1.25 0.5 2 5 2 2 0.5 6 2.5 1.25 1.25 7 4 One 3 8 5 3 One 9 10 2 2 10 One 4 11 4 One 12 2 3 13 3 2 14 2.5 2.5 15 5 5 16 10 10

- UL slot number indicator: The corresponding indicator can be used interchangeably as a sidelink slot number indicator, and is information indicating how many slots are indicated as UL slots from the end of the corresponding transmission period. For example, if one transmission period consists of 10 and the UL slot number indicator value indicates 3, it may be informed that the last 3 slots among 10 slots are configured as UL slots. The bits of the UL slot number indicator may consist of n bits, and when one transmission period pattern is indicated, the number of UL slots (S1) in the corresponding transmission period P1 is indicated, and when two transmission period patterns are indicated, The number of UL slots (S1, S2) in (P1, P2) in each transmission period is simultaneously informed. For this, the following Equation 1 or Equation 1A may be used.

[Equation 1]

SIV = C ₁ '*B' + A'

, B'=

, A'=

,

,

where C ₁ '=

, B'=

, A'=

,

,

[Equation 1A]

SIV = C ₁ '*B' + A'

, B'=

, A'=

,

,

where C ₁ '=

, B'=

, A'=

,

,

이면, K=

이고, 그 이외 경우는, K=1이다. 또는, 상기 조건과 관계없이, K=

이 적용될 수 있다.In Equation 1 (or Equation 1A), SIV is an abbreviation of Sidelink Resource Indication Value, and is a value expressed by another term for the UL slot number indicator. SIV is merely an example for convenience of description, and may be substituted with other abbreviations or terms having similar meanings. C ₁ is the total number of slots included in the transmission period (P1) of the first pattern, C ₂ is the total number of slots included in the transmission period (P2) of the second pattern, A is the number of UL slots in the transmission period (P1) of the first pattern The actual number of UL slots indicated by the indicator (S1), B is the actual number of UL slots (S2) indicated by the UL slot number indicator in the transmission period P2 of the second pattern. K is _{a value determined by C 1} and C ₂ and the number of UL slot number indicator bits (n), for example,

If , K=

, and in other cases, K=1. or, irrespective of the above conditions, K=

This can be applied.

단위로 지시하고, 두번째 전송 패턴 내의 UL 슬롯들을 B = 0, 1*K, 2*K, ...,

단위로 지시할 수 있다.As another example, by Equation 1 (or Equation 1A), SIV assigns UL slots in the first transmission period pattern to A = 0, 1*K, 2*K, ...,

Indicate as a unit, and UL slots in the second transmission pattern are B = 0, 1*K, 2*K, ...,

can be specified in units.

When only one pattern is indicated by the transmission period pattern number indicator, the terminal indicates the total number of slots (C ₂ ) included in the second transmission period (P2) and the transmission period (P2) of the second pattern, B is the transmission period of the second pattern The actual number of UL slots indicated in (P2) (S2), B is considered to be 0, and Equation 1 (or Equation 1A) becomes SIV = A'.

)는 round 함수(

) 또는 flooring (

)로 일부 또는 전체가 대체되어 적용될 수 있다. 또한, K=

에서 적용된 ceiling 함수(

)는 round 함수(

) 또는 flooring (

)로 대체되어 적용될 수 있다. 일례로, UL 슬롯 개수 지시자가 7비트(n=7)일 경우,

이면, K=

이고, 그 이외 경우는, K=1이다. In addition, in the case where one pattern is indicated, it may be possible to consider K=1 regardless of the above conditions for determining the K value. The ceiling function applied in Equation 1 (or Equation 1A) above

) is the round function (

) or flooring (

) may be partially or entirely replaced with Also, K=

The ceiling function applied in (

) is the round function (

) or flooring (

) can be replaced with As an example, when the UL slot number indicator is 7 bits (n = 7),

If , K=

, and in other cases, K=1.

As another example, when two transmission period patterns are indicated by Equation 1 (or Equation 1A), S1 has a value of 0*K, 1*K, 2*K, 3*K, ... , S2 has values of 0*K, 1*K, 2*K, 3*K, .... Equation 1 may be a possible method when the same K value is applied to each transmission period pattern, and Equation 2 may be a possible method when different K values are applied to each transmission period pattern.

[Equation 2]

SIV = C ₁ ' * B' + A'

, B'=

, A'=

,

,

where C ₁ '=

, B'=

, A'=

,

,

이면, K₁=

이고, 그 이외 경우는, K=1이다. 또 다른 일례로, 일례로,

이면, K₂=

이고, 그 이외 경우는, K=1이다. 이를 일반화화면,

이면, K_i=

이고, 그 이외 경우는, K=1이다. 또는, 상기 조건과 관계없이, K₁=

또는 K₂=

이 적용될 수 있다.Equation 2 has a similar concept to Equation 1 (or Equation 1A), but K ₁ and K ₂ values are used instead of K values. K ₁ is _{a value determined by C 1} and the number of UL slot number indicator bits (n), and K ₂ is _{a value determined by C 2} and the number of UL slot number indicator bits (n), for example,

If , then K ₁ =

, and in other cases, K=1. In another example, for example,

If , K ₂ =

, and in other cases, K=1. This is a generalization screen,

If , then K _i =

, and in other cases, K=1. or, irrespective of the above conditions, K ₁ =

or K ₂ =

This can be applied.

)는 round 함수(

) 또는 flooring (

)로 대체되어 적용될 수 있다.A case indicated by one pattern may be regarded as _{K 1} =1 regardless of the above conditions for determining the _{K 1 value, and K 2} does not exist. As another example, the value of n in the above equation may be n=7 when the UL slot number indicator is 7 bits. The ceiling function applied in the above formula (

) is the round function (

) or flooring (

) can be replaced with

As another example, it may be possible to inform the UL slot number indicator information by Equation (3).

[Equation 3]

SIV = (C ₁ + 1) * B + A

,

where

,

Equation 3 uses a definition similar to Equation 1 (or Equation 1A) or Equation 2, but there is no K value. Instead, the reference subcarrier interval indicating the UL slot number indicator information is determined according to the transmission period pattern number indicator and a specific value determined by the transmission period indicator. For example, when the UL slot number indicator information is informed on the basis of the 15 kHz subcarriers by the transmission period pattern number indicator and the transmission period indicator in a situation where the sidelink resource operates at 120 kHz subcarrier intervals, the terminal indicates the 15 kHz subcarrier reference. The UE may consider that one UL slot is applied to a total of 8 slots.

19 is a diagram illustrating a slot structure according to subcarrier spacing. 19, 1900 denotes a 15 kHz reference slot structure, 1902 denotes a 30 kHz reference slot structure, and 1904 denotes a 60 kHz reference slot structure. In a situation in which the terminal receives the TDD configuration information based on the normal cyclic prefix and 15 kHz, but the actual sidelink communication operates at 60 kHz and the normal cyclic prefix, the terminal uses the TDD configuration information based on 1900 in FIG. 19 to 13 , when receiving the information that the slots of 14 are used as UL slots (or sidelink communication slots), the terminal actually performs sidelink communication in 1904 of 13a, 13b, 13c, 13d, 14a, 14b, 14c, 14d It is determined that the slots are configured as UL slots (or sidelink communication slots). As another example, it may be possible for the UE to assume that Equation 3 always provides TDD configuration information based on a slot based on a 15 kHz subcarrier interval and a normal cyclic prefix. As another example, the normal cyclic prefix and the reference subcarrier interval (μ _k ) in the TDD configuration information may be determined by the following Equation (4).

[Equation 4]

_{Definitions and candidate values of C 1} , C ₂ , and n in [Equation 4] are the same as the values described above in [Equation 1] (or Equation 1A) to [Equation 3]. μ _i means a subcarrier interval at which the UE actually performs sidelink communication. The relationship between μ value and subcarrier spacing follows Table 7 below. For example, in a situation where the terminal performs sidelink communication at 120 kHz and the transmission period pattern is set to two (P1, P2), each transmission period is 10 ms (P1 = 10 ms, P2 = 10 ms, that is, C ₁ =C ₂ = 80), and n is 7 bits, the μ _k value is determined to be 0 by the above equation, and the UE uses the UL slot (or The number of slots for sidelink communication) is determined.

)는 round 함수(

) 또는 flooring (

)로 대체되어 적용될 수 있다.To summarize, according to Equation 4, the reference subcarrier interval value (μ _k ) applied to the UL slot number indicator is the total number of slots per transmission period indicated by the transmission period pattern number indicator and the transmission period indicator in the TDD configuration information ( C ₁ , C ₂ ), the number of bits for the UL slot number indicator in the TDD configuration information (n), and the subcarrier interval value (μ _i ) at which the UE actually performs sidelink communication is determined. _{As described in the present invention, the subcarrier interval value μ i} performing the actual side link communication may enable the UE to determine a preset value by a frequency band or region, a resource pool, or a combination thereof. The ceiling function applied in Equation 4 (

) is the round function (

) or flooring (

) can be replaced with

Subcarrier Spacing (kHz) μ (eg, μ _i or μ _k ) 15 0 30 One 60 2 120 3 240 4

For example, the TDD configuration information may have a total of 12 bits consisting of a 1-bit transmission period pattern number indicator, a 4-bit transmission period indicator, and a 7-bit UL slot number indicator.

The embodiments disclosed in the present specification and drawings above are merely specific examples to easily explain the contents of the present disclosure and help understanding, and are not intended to limit the scope of the present disclosure. Therefore, the scope of the present disclosure should be construed as including all changes or modifications derived based on the present disclosure in addition to the embodiments disclosed herein as being included in the scope of the present disclosure.

In addition, some or all of certain embodiments may be performed in combination with some or all of other embodiments, and it is of course also within the scope of the present disclosure that two or more embodiments are connected or performed in combination with each other.

Claims (1)

A control signal processing method in a wireless communication system, comprising:
Receiving a first control signal transmitted from the base station;
processing the received first control signal; and
and transmitting a second control signal generated based on the processing to the base station.

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