WO2020032704A1

WO2020032704A1 - Method and device for performing synchronization procedure for nr v2x system

Info

Publication number: WO2020032704A1
Application number: PCT/KR2019/010102
Authority: WO
Inventors: 박동현; 윤성준
Original assignee: 주식회사 아이티엘
Priority date: 2018-08-10
Filing date: 2019-08-09
Publication date: 2020-02-13

Abstract

The present invention may provide a method for performing a synchronization procedure by a terminal in an NR V2X system. Here, the method for performing the synchronization procedure may comprise the steps of: determining whether a frequency for V2X sidelink communication of a terminal is within coverage on a network; and selecting a synchronization reference source on the basis of whether the frequency is within the coverage on the network.

Description

Method and apparatus for performing synchronization procedure for NR V2X system

The present invention relates to a synchronization signal transmission and reception method and a synchronization procedure for a NR (New Radio) Vehicle To Everything (V2X) system.

The present invention relates to a method for setting a sidelink-synchronization signal block (SL-SSB) transmission resource for a NR (New Radio) Vehicle To Everything (V2X) system.

The International Telecommunication Union (ITU) is developing the International Mobile Telecommunication (IMT) framework and standards, and is currently in discussions for 5G (5G) communication through a program called "IMT for 2020 and beyond." .

In order to meet the requirements set forth in "IMT for 2020 and beyond", the 3rd Generation Partnership Project (3GPP) New Radio (3GPP) system is based on time-frequency, considering various scenarios, service requirements, and potential system compatibility. It is discussed in the direction of supporting various numerologies for resource unit criteria.

In addition, V2X communication refers to a communication method of exchanging or sharing information such as traffic conditions while communicating with road infrastructure and other vehicles while driving. V2X is a vehicle-to-vehicle (V2V) that stands for Long Term Evolution (LTE) -based communication between vehicles, a vehicle-to-pedestrian (V2P) that stands for LTE-based communication between terminals carried by vehicles and individuals, and vehicles And vehicle-to-infrastructure / network (V2I / N), which means LTE-based communication between a roadside unit and a network. Here, the roadside unit (RSU) may be a transportation infrastructure entity implemented by a base station or a fixed terminal. For example, it may be an entity that transmits a speed notification to the vehicle.

The present invention can provide a method of performing a synchronization procedure in an NR V2X system.

The present invention can provide a method for selecting a synchronous reference source based on whether the NR V2X sidelink frequency of an NR V2X sidelink (SL) terminal is included in coverage on a network.

The present invention can provide a method for selecting a synchronous reference source when the NR V2X sidelink frequency is In-Coverage (IC).

The present invention can provide a method of selecting a synchronous reference source when the NR V2X sidelink frequency is out-of-coverage (OCC).

The present invention can provide a method for configuring a SL-SSB transmission resource for an NR V2X system.

The present invention can provide a method for configuring an SL-SSB transmission resource in terms of frequency domain.

The present invention can provide a method for configuring an SL-SSB transmission resource from a time domain perspective.

The present invention can provide a method for configuring an SL-SSB transmission resource in consideration of a relationship with a downlink-SSB (DL-SSB).

The present invention can provide a method for a UE to perform a synchronization procedure in an NR V2X system. In this case, the method of performing a synchronization procedure includes determining whether a frequency for V2X sidelink communication of a terminal is within coverage on a network, and selecting a synchronization reference source based on whether the frequency is within coverage on a network. can do.

The present invention can provide a method for a UE to configure resources in an NR V2X system. At this time, the resource setting method may include the step of the terminal receiving the resource configuration information for the SL-SSB transmission from the base station and transmitting the SL-SSB based on the received resource configuration information. In this case, the resource configuration information for the SL-SSB transmission may include frequency position information for the SL-SBB and time position information for the SL-SSB.

According to the present disclosure, a method of performing a synchronization procedure in an NR V2X system may be provided.

According to the present disclosure, a method of selecting a synchronization reference source based on whether an NR V2X sidelink frequency of an NR V2X sidelink terminal is included in coverage on a network.

According to the present disclosure, when the NR V2X sidelink frequency is in coverage, a method of selecting a synchronization reference source may be provided.

According to the present disclosure, when the NR V2X sidelink frequency is out of coverage, a method of selecting a synchronization reference source may be provided.

According to the present disclosure, it is possible to provide a method for configuring a SL-SSB transmission resource for an NR V2X system.

According to the present disclosure, it is possible to provide a method for configuring an SL-SSB transmission resource from a frequency domain perspective.

According to the present disclosure, it is possible to provide a method for configuring a SL-SSB transmission resource from a time domain perspective.

According to the present disclosure, it is possible to provide a method for configuring a SL-SSB transmission resource in consideration of a relationship with a downlink-SSB (DL-SSB).

Effects obtained in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

1 is a diagram showing a frame structure for downlink / uplink transmission to which the present disclosure can be applied.

2 is a diagram illustrating a resource grid and a resource block to which the present disclosure may be applied.

3 is a diagram illustrating a synchronization signal transmission method according to an embodiment of the present invention.

4 illustrates a system architecture in accordance with an embodiment of the present invention.

5 is a diagram illustrating a method of transmitting a synchronization signal.

6 is a diagram illustrating a scenario in which NR V2X sidelink communication is performed in a 3GPP network.

7 is a diagram illustrating a method of selecting a synchronization reference source in incoverage.

8 illustrates a method of selecting a synchronous reference source in out of coverage.

9 illustrates a scenario in which NR V2X sidelink communication is performed in a 3GPP network according to an embodiment of the present invention.

10 is a diagram illustrating a BWP configuration associated with a cell connection of an NR Uu link according to an embodiment of the present invention.

11 illustrates a relationship between a resource pool and a SLSS / PSBCH block according to an embodiment of the present invention.

12 is a diagram illustrating a method for indicating NR side link resource pool and SL-SSB configuration using system information provided for each cell according to an embodiment of the present invention.

13 is a diagram illustrating operation in an NR TDD band according to an embodiment of the present invention.

14 is a diagram illustrating a method for indicating an NR SL-SSB frequency position based on a start position of a transmission bandwidth according to an embodiment of the present invention.

15 is a diagram illustrating a method of indicating NR SL-SSB frequency location based on an NR sidelink resource pool according to an embodiment of the present invention.

16 illustrates a method of configuring and indicating an NR SL SSB burst set according to an embodiment of the present invention.

17 is a diagram illustrating a configuration and indication method of an NR SL SSB burst set according to an embodiment of the present invention.

18 illustrates a method of setting a start offset and an SL SSB burst window interval based on a slot (or slot + OFDM symbol) unit according to an embodiment of the present invention.

FIG. 19 illustrates a method of setting a start offset and an SL SSB burst window interval based on a slot (or slot + OFDM symbol) unit according to an embodiment of the present invention.

20 is a diagram illustrating an operation for additional signaling in consideration of a TDD case according to an embodiment of the present invention.

21 is a diagram illustrating operation of additional signaling in consideration of a TDD case according to an embodiment of the present invention.

FIG. 22 is a diagram illustrating a case where an SL-SSB available in an "UL slot" or an "UL slot + symbol" may be located according to an embodiment of the present invention.

FIG. 23 illustrates a floating sidelink SSB burst structure according to an embodiment of the present invention. FIG.

24 illustrates a case where a DL SSB burst window and an SL SSB burst window overlap according to an embodiment of the present invention.

25 is a flowchart illustrating a method of selecting an SL-SSB resource according to an embodiment of the present invention.

26 is a diagram showing the configuration of a base station apparatus and a terminal apparatus according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present disclosure. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In describing the embodiments of the present disclosure, when it is determined that a detailed description of a known structure or function may obscure the gist of the present disclosure, a detailed description thereof will be omitted. In the drawings, parts irrelevant to the description of the present disclosure are omitted, and like reference numerals designate like parts.

In the present disclosure, when a component is "connected", "coupled" or "connected" with another component, it is not only a direct connection, but also an indirect connection in which another component exists in the middle of the connection. It may also include. In addition, when a component "includes" or "having" another component, it means that it may further include another component, without excluding the other component unless otherwise stated. .

In the present disclosure, the terms "first" and "second" are used only for the purpose of distinguishing one component from other components, and do not limit the order or importance between the components unless specifically mentioned. Thus, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and likewise, a second component in one embodiment may be referred to as a first component in another embodiment. It may also be called.

In the present disclosure, the components distinguished from each other are for clearly describing each feature, and do not necessarily mean that the components are separated. That is, a plurality of components may be integrated into one hardware or software unit, or one component may be distributed into a plurality of hardware or software units. Therefore, even if not mentioned otherwise, such integrated or distributed embodiments are included in the scope of the present disclosure.

In the present disclosure, components described in various embodiments are not necessarily required components, and some may be optional components. Accordingly, embodiments that consist of a subset of the components described in one embodiment are also included in the scope of the present disclosure. In addition, embodiments including other components in addition to the components described in the various embodiments are included in the scope of the present disclosure.

In addition, the present specification describes a wireless communication network, the operation performed in the wireless communication network is performed in the process of controlling the network and transmitting data in a system (for example, a base station) that manages the wireless communication network, or the corresponding wireless Work can be done at the terminal coupled to the network.

That is, it is apparent that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. A 'base station (BS)' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point (AP), and the like. In addition, the term 'terminal' may be replaced with terms such as user equipment (UE), mobile station (MS), mobile subscriber station (MSS), subscriber station (SS), and non-AP STA. Can be.

In the present disclosure, transmitting or receiving a channel includes transmitting or receiving information or a signal through the channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal over the data channel.

In the following description, the term NR system is used for the purpose of distinguishing a system to which various examples of the present disclosure are applied from an existing system, but the scope of the present disclosure is not limited thereto. In addition, although the term NR system is used as an example of a wireless communication system capable of supporting various subcarrier spacings (SCS), the term NR system itself is a wireless communication system supporting a plurality of SCS. It is not limited.

1 is a diagram illustrating an NR frame structure and a numerology according to an embodiment of the present invention.

In NR, the base unit of time domain is

Can be. At this time,

ego,

Can be. Also,

May be a constant for a multiple relationship between an NR time unit and an LTE time unit. In LTE as a reference time unit

,

And

Can be defined.

프레임 구조Frame structure

Referring to FIG. 1, the time structure of a frame for downlink and uplink (DL / UL) transmission is

It can have In this case, one frame

It consists of 10 subframes corresponding to time. The number of consecutive OFDM symbols per subframe

Can be. In addition, each frame is divided into two half frames, and the half frame may include 0 to 4 subframes and 5 to 9 subframes. In this case, half frame 1 may include 0 to 4 subframes, and half frame 2 may include 5 to 9 subframes.

In this case, the transmission timing of the uplink transmission frame i is determined based on Equation 1 based on the downlink reception timing in the terminal.

In Equation 1 below

May be a TA offset value generated due to a duplex mode difference or the like. By default, FDD (Frequency Division Duplex)

Has zero but TDD (Time Division Duplex) considers margin for DL-UL switching time

Can be defined as a fixed value.

[Equation 1]

2 is a diagram illustrating a resource grid and a resource block.

Referring to FIG. 2, resource elements in a resource grid may be indexed according to each subcarrier spacing. In this case, one resource grid may be generated for each antenna port and each subcarrier spacing. Uplink and downlink transmission and reception may be performed based on a corresponding resource grid.

One resource block is composed of 12 resource elements (Resource Element) in the frequency domain, as shown in Equation 2 index for one resource block for each 12 resource elements

) Can be configured. The index for the resource block may be utilized within a specific frequency band or system bandwidth.

[Equation 2]

뉴머놀러지(Numerologies)Numerologies

Numerology can be configured in various ways to meet the various services and requirements of the NR system. In this case, referring to Table 1 below, numerology may be defined based on subcarrier spacing (SCS), CP length, and number of OFDM symbols per slot used in an orthogonal frequency division multiplexing (OFDM) system. . The above-described values may be provided to the terminal through higher layer parameters DL-BWP-mu and DL-BWP-cp (DL) and UL-BWP-mu and UL-BWP-cp (UL).

In addition, as an example, in Table 1 below

When 2 is a subcarrier spacing of 60 kHz, a normal CP and an extended CP may be applied, and in other bands, only a normal CP may be applied.

TABLE 1

In this case, the normal slot may be defined as a basic time unit used to basically transmit one data and control information in the NR system. The length of a normal slot may basically consist of 14 OFDM symbols. In addition, unlike a slot, a subframe may be used as a reference time for the length of another time interval with an absolute time length corresponding to 1 ms in the NR system. In this case, a time interval such as a subframe of LTE may be required for the NR specification for coexistence or backward compatibility of the LTE and NR systems.

For example, in LTE, data may be transmitted based on a transmission time interval (TTI), which is a unit time, and the TTI may be configured by one or more subframe units. In this case, even in LTE, one subframe may be set to 1 ms and 14 OFDM symbols (or 12 OFDM symbols) may be included.

In addition, non-slots may be defined in NR. The nonslot may refer to a slot having a number smaller than at least one symbol than a normal slot. For example, in case of providing low delay time such as Ultra-Reliable and Low Latency Communications (URLLC) service, delay time may be reduced through nonslots having a smaller number of symbols than normal slots. In this case, the number of OFDM symbols included in the nonslot may be determined in consideration of the frequency range. For example, a nonslot of 1 OFDM symbol length may be considered in a frequency range of 6 GHz or more. As another example, the number of OFDM symbols defining the nonslot may include at least two OFDM symbols. In this case, the range of the number of OFDM symbols included in the non-slot may be configured as the length of the mini slot to the normal slot length-1. However, the number of OFDM symbols may be limited to 2, 4, or 7 symbols as a nonslot standard, but is not limited to the above-described embodiment.

For example, in the unlicensed band of 6 GHz or less

Subcarriers spacing equal to 1 and 2 are used, and for unlicensed bands above 6 GHz,

Subcarrier spacing corresponding to 3 and 4 may be used. At this time, for example,

If 4 is used only for the Synchronization Siganl Block (SSB) to be described later, it is not limited to the above-described embodiment.

In addition, Table 2 shows each subcarrier spacing setting in case of normal CP.

Number of OFDM Symbols Per Slot

Indicates. Table 2 shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe according to each subcarrier spacing value, as provided in Table 1. In this case, Table 2 shows the above values based on the normal slot having 14 OFDM symbols.

TABLE 2

In addition, as described above,

Is 2, the extended CP may be applied when the subcarrier spacing is 60 kHz. Table 3 shows the case of extended CP.

Number of OFDM Symbols Per Slot

May represent each value based on a normal slot of 12. In this case, referring to Table 3, in case of an extended CP according to 60 kHz subcarrier spacing, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe may be indicated.

TABLE 3

Next, the structure of the SSB / PBCH (Physical Broadcast Channel) in the NR system and the initial cell access procedure in the NR system will be described.

In this case, the NR base station (i.e. gNB) may periodically transmit signals and channels shown in Table 4 to the terminals to allow initial cell selection of the terminals (i.e. UEs) in the cell.

TABLE 4

For example, the SS / PBCH block may be the aforementioned SSB. In this case, in order to perform the initial radio access in the NR system, it may be necessary to receive a broadcast channel that transmits synchronization signals and important system information transmitted from the radio access system. To this end, the terminal may check the reception sensitivity of the synchronization signal (Synchronization Signal) in order to find the optimal cell in the best channel environment. The terminal may perform frequency / time synchronization and cell identification for initial access to an optimal channel among one or more channels within a specific frequency band operated based on the checked reception sensitivity. The UE can check the boundary of the OFDM symbol timing through the above-described operation, and can then start PBCH decoding in the same SSB.

In this case, the UE may perform PBCH decoding by receiving a PBCH Demodulation Reference Signal (DMRS). In addition, the UE may obtain 3 LSB bit information among the SSB index information bits through the PBCH DMRS. Thereafter, the UE may acquire information included in the PBCH payload by performing PBCH decoding. Thereafter, the UE may perform a decoding procedure of SIB 1 using the information obtained through the PBCH.

For example, in an NR system, a UE may receive Remaining System Information (RMSI) as a system information not transmitted through a PBCH through a broadcast signal or a channel. In addition, the terminal may receive other system information (OSI) and paging channel as a broadcast signal or channel as additional system information.

Thereafter, the terminal may access the base station through a random access channel (RACH) procedure and may then perform mobility management.

In addition, as an example, when the terminal receives the SSB, there is a need to set the SSB composition and the SS Burst Set composition.

NR V2X 서비스NR V2X Service

In terms of V2X services, existing V2X services (e.g. LTE Rel-14 V2X) could support a set of basic requirements for V2X services. At this time, the requirements were basically designed with full consideration of road safety service. Accordingly, V2X user equipments (UEs) may exchange self-state information through sidelinks, and exchange the above-described information with infrastructure nodes and / or pedestrians. It became possible.

On the other hand, in a more advanced service (eg LTE Rel-15) as a V2X service, carrier aggregation in the sidelink, high order modulation, latency reduction, and transmission diversity (Tx) Considering the diversity and feasibility of sTTI, new features are introduced. Based on the above, coexistence (same resource pool) with V2X UEs was required, and the above-described services were provided based on LTE.

For example, in consideration of use cases for supporting a new V2X service as SA (System Aspect) 1, technical features may be classified based on four categories as shown in Table 5 below. At this time, the group driving (Vehicles Platooning) in Table 5 may be a technique in which a plurality of vehicles dynamically form a group, and operates similarly. In addition, extended sensors may be a technology for collecting and exchanging data obtained from a sensor or a video image. Also, Advanced Driving may be a technology in which a vehicle is driven based on fully automated or semi-automated. In addition, remote driving may be a technology for providing a technology and an application for remote control of a vehicle, and the details of the above may be as shown in Table 5 below.

TABLE 5

In addition, SA1 described above may be considered both LTE and NR as an enhanced V2X (eV2X) supporting technology for supporting a new V2X service. As an example, the NR V2X system may be a first V2X system. In addition, the LTE V2X system may be a second V2X system. That is, the NR V2X system and the LTE V2X system may be different V2X systems. In the following, related contents will be described based on a method for satisfying the low delay and high reliability required in the NR sidelink based on the NR V2X system. However, the same or similar configuration may be extended and applied to the LTE V2X system, and is not limited to the following embodiments. That is, the LTE V2X system can be applied to the part that can be interoperable, and is not limited to the following embodiments. In this case, as an example, NR V2X capability may not necessarily be limited to supporting only V2X services, and what V2X RaT is used may be selected.

3 is a diagram illustrating a method of transmitting sidelink synchronization information.

Referring to FIG. 3, sidelink synchronization information may be transmitted. In this case, as an example, FIG. 3A may be a method of transmitting synchronization information of a first V2X system (or an LTE V2X system). Also, FIG. 3B may be a method for transmitting synchronization information of a second V2X system (or an NR V2X system).

Referring to FIG. 3 (a), the signaling for transmission of synchronization information of LTE sidelink for V2X may be considered to be In Coverage (IC) or In Partial Coverage. In this case, the following description will be based on the case of IC, and may be similarly applied to the case of partial in coverage, and is not limited to the above-described embodiment.

In addition, the signaling for transmission of synchronization information of the LTE sidelink may consider the case of Out of Coverage (OOC). In this case, for example, in the case of the IC, the terminal 301 may receive configuration information for transmission of a synchronization signal through a system information block (SIB) 18 and / or SIB 21 from a base station 302 (EUTRAN). In addition, as an example, when the terminal 303 is in an RRC connected state, configuration information for synchronization signal transmission may be transmitted through an RRC connection message. In this case, the terminal may transmit synchronization information to another terminal through the SLSS & Master Information Block-SL and / or Master Information Block-SL-V2X based on the configuration information. Through this, synchronization information of the sidelink may be transmitted.

Meanwhile, in the case of OOC, the terminal 303 may include synchronization information in the SLSS & Master Information Block-SL and / or Master Information Block-SL-V2X to provide the synchronization information to the other terminal 304. It is not limited to an Example.

Also, as an example, referring to FIG. 3 (b), in the case of an IC, as a second V2X system (NR V2X system), the terminal 305 is a synchronization signal from the base stations 306 and NR through OSI (Other System Information). Setting information for transmission can be obtained. Also, as an example, when the terminal 305 is in an RRC connection state, configuration information for transmission of a synchronization signal may be transmitted through an RRC connection message. In this case, the terminal 305 may include synchronization information in the NR SLSS and / or NR V2X MIB through the sidelink and transmit the same to other terminals.

On the other hand, in the case of OOC, the terminal 307 may provide synchronization information to the other terminal 308 by including the synchronization information in the NR SLSS and / or NR V2X MIB, is not limited to the above-described embodiment.

In addition, as an example, in the second V2X system (NR V2X system) similar to FIG. 3 (a), in the case of the IC, the terminal 309 configures information for transmitting a synchronization signal through the SIB 21 from the base station 310 (EUTRAN). Can be received. Also, as an example, when the terminal 309 is in an RRC connected state, configuration information for transmission of a synchronization signal may be transmitted through an RRC connection message. In this case, the terminal may transmit synchronization information to another terminal through the Master Information Block-SL-V2X based on the setting information. Through this, synchronization information of the sidelink may be transmitted.

On the other hand, in the case of OOC in the second V2X system (NR V2X system), the terminal 311 may provide the synchronization information to the other terminal 312 by including the synchronization information in the NR SLSS and / or NR V2X MIB. It is not limited to one embodiment.

That is, in the case of the IC, the V2X terminal receives the system information as described above for the information on the side synchronization synchronization (SL synchronization) transmission from the network based on the LTE / NR Uu link (link between the eNB or gNB and the terminal). You can be provided with the configuration. At this time, as described above, a method for transmitting synchronization information on the sidelink includes network signaling based transmission and terminal based transmission. In this case, the UE may receive a synchronization signal and system configuration information for V2X-MIB transmission from the LTE and / or NR base station and perform NR SL-SSB transmission based thereon. In this case, if the UE is connected to the LTE cell and / or the NR cell in the RRC connection mode, the system configuration information is provided to the UE through an RRC reset message, and the UE may perform NR SL-SSB transmission based on the information. .

Meanwhile, in the case of terminal-based transmission, in the case of IC, the terminal may be provided through a broadcasting signal (e.g: system information) of the base station. Alternatively, in the case of OOC, it may be determined whether to transmit synchronization information based on a preset threshold value, and the present invention is not limited to the above-described embodiment.

Based on the above description, the synchronization information transmitted by the terminal may be obtained based on the signal and information received from the base station in the IC. Also, as an example, the synchronization information transmitted by the terminal may be obtained from another sidelink transmission terminal. In addition, as an example, the synchronization information transmitted by the terminal may be derived based on the signal and information received from the GNSS.

In the following description, a terminal for generating synchronization information by itself and transmitting synchronization information is referred to as a synchronization reference terminal (i.e., SyncRef UE). That is, the terminal may generate synchronization information on its own based on the obtained information and transmit it to another terminal, as described above. In this case, for example, in case of OOC, NR-SSB transmission may be performed based on SLSS and MIB information provided from a synchronization reference terminal, which may be to provide dictionary information for transmitting synchronization information to a terminal.

In the following, a synchronization signal transmission method and a synchronization procedure will be described based on the above description. In this case, as an example, the NR sidelink frequency may consider FR1 (i.e. up to 52.6 GHz), which is a frequency below 6 GHz and FR2, a frequency above 6 GH. In addition, as an example, the NR sidelink frequency may be considered both unlicensed ITS bands and licensed bands. That is, as described above, a common design method for supporting each frequency band band may be needed. To this end, an NR sidelink design considering the NR system may be required. For example, an NR sidelink design capable of basically supporting beam-based transmission / reception may be required even if the omni-directional Tx / Rx is not actually beam-based, like the NR standard design, but is not limited to the above description. . In addition, Table 6 may be each term applied in the following invention, but is not limited to the above-described embodiment.

TABLE 6

NR 사이드 링크 디자인NR side link design

The following describes an NR V2X sidelink design method that satisfies the requirements for advanced V2X (i.e. eV2X) services described above.

More specifically, the synchronization procedure and method required for forming a radio link for the NR sidelink will be described in detail. For example, as described above, in the NR side link design, as the NR side link frequencies, FR1 and FR2 (ie up to 52.6 GHz) and unlicensed ITS bands and licensed bands ITS are frequency bands in which the NR system operates. And both may be considered as a range. Also, as an example, the availability of the LTE (NG-eNB) / NR Uu link, which is the 3GPP NG-RAN network of Table 6 described above, may be considered in the NR sidelink design.

Also, as an example, a design for eV2X synchronization information transmission and signal transmission / reception may be considered to satisfy higher requirements from the above-described advanced V2X services. In this case, the frequency for the NR V2X sidelink communication may be considered at least one or more of the elements shown in Table 7 below based on the technologies required in the new system, unlike the existing system (e.g. LTE). That is, as shown in Table 7 below, it is necessary to satisfy the new V2X service requirements by applying the NR V2X side link based on NR radio access technology, in particular, uplink transmission related technologies.

In addition, other factors may be considered in consideration of the new system as well as Table 7 below, and are not limited to the above-described embodiment.

TABLE 7

Also, as an example, the physical channels, signals, basic slot structures, and physical resources of the NR V2X sidelink may be as shown in Table 8 below.

TABLE 8

Also, as an example, FIG. 4 may be a basic network architecture configuration considering NR V2X sidelinks.

As an example, referring to FIG. 4, nodes 410-1 and 410-2 and NG-RAN nodes 420-1, 420-2, 430-1, and 430-2 of 5G Core NW. The NG interface can be set in between. In addition, an Xn interface may be set between the NG-RAN nodes 420-1, 420-2, 430-1, and 430-2. In this architecture, gNB (NR UP / CP protocol, 420-1, 420-2) and NG-eNB (E-UTRA UP / CP protocol, 430-1, 430-2) constituting NG-RAN in the above-described architecture are used. At the center, the nodes can be interconnected through the Xn interface. In addition, as described above, the 5GC may be connected through an NG interface. At this time, for example, in the above-described architecture, both the LTE sidelink terminal and the NR sidelink terminal may be controlled by NG-RAN (i.e. LTE Uu and NR Uu) based on gNB and NG-eNB. Therefore, when the NR sidelink terminal transmits the synchronization information, it is possible to receive the synchronization information from the LTE Uu or NR Uu link and transmit the NR sidelink synchronization information (eg SL Synchronization Signal / SL Physical broadcast Channel) based on the information. It is not limited to the above-mentioned embodiment. That is, the NR sidelink terminal may acquire synchronization information not only through the NR Uu link but also through the LTE Uu link.

Meanwhile, in relation to the V2X side link communication, the V2X side link terminals may perform V2X side link communication. However, in order for V2X sidelink terminals to start communication, certain conditions need to be satisfied. Conditions for this may be as shown in Table 9 below. That is, the V2X sidelink terminal may perform V2X sidelink communication in an RRC idle state, an inactive state, or a connected mode. In addition, V2X sidelink terminals performing V2X sidelink communication need to be registered in a cell selected on the frequency used or belong to the same PLMN. In addition, when the V2X sidelink terminal is OOC on the frequency for V2X sidelink communication, V2X sidelink communication may be performed only when the V2X sidelink communication can be performed based on pre-configuration information. .

TABLE 9

At this time, as described above, sidelink synchronization information may be required to start V2X sidelink communication. Accordingly, the terminal needs to transmit sidelink synchronization information. However, the transmitting terminal (Sidelink Tx UE) may receive a configuration for transmitting sidelink synchronization information before transmitting the corresponding synchronization information. In this case, as an example, the transmitting terminal may receive a configuration for transmitting sidelink synchronization information based on a system information message or an RRC reset message (in case of an RRC CONNECTED UE) broadcast from the NG-RAN nodes described above. In addition, as an example, when the NR V2X sidelink terminal (hereinafter referred to as a terminal) does not exist in the NG-RAN network, the sidelink synchronization information may be transmitted based on previously set information, as described above.

At this time, terminals capable of NR V2X sidelink communication may first perform SLSS / PSBCH transmission. For example, FIG. 5 is a diagram illustrating a method for transmitting a SLSS / PSBCH by a transmitting terminal.

More specifically, referring to FIG. 5, the transmitting terminal may receive the setting for the synchronization information as described above. In this case, as described above, the configuration for the synchronization information may be received through the RRC resetting message or the system information broadcast from the NG-RAN nodes. Also, as an example, preset information may be used, as described above. In this case, the terminal may determine synchronization information for transmission based on information received from the base station or preset information. For example, the LTE / NR base station may provide configuration information for transmitting corresponding synchronization information to the terminal through system information such as SIB21 / OSI, as described above. In addition, if the terminal does not receive the above-described information, it may be able to perform SLSS / PSBCH transmission on the basis of preset information.

Next, initialization may be performed. In this case, the terminal may check whether the frequency for the V2X sidelink communication is within in-coverage. In addition, the UE may determine whether a synchronization reference for the GNSS or a synchronization reference for the cell is selected as a synchronization reference. In addition, the terminal can determine whether the mode is to control the synchronization signal transmission in the network. In this case, as an example, whether or not the SLSS / PSBCH is transmitted may be determined according to whether the network is in a mode for controlling synchronization signal transmission.

Next, the transmitting terminal may perform the SLSS / PSBCH transmission. In this case, the transmitting terminal may determine whether to transmit the SLSS / PSBCH and a transmission method based on the information determined in the initialization step, which will be described later. The following describes a procedure and method for synchronous reference selection / reselection of SLSS / PSBCH transmission for NR V2X sidelink communication based on the above description.

실시예 (NR V2X SLSS/PSBCH 블록 전송을 위한 동기 참조의 소스 선택/재선택 방법)Embodiment (Source Selection / Reselection Method of Synchronous Reference for NR V2X SLSS / PSBCH Block Transmission)

Based on the above, the terminal can determine the source for the synchronous reference. In this case, the terminal may first determine a resource corresponding to a slot or time domain in which a Sidelink SSID (SLSSID) and a NR SL Sidelink Synchronization Signal Block (SSB) are transmitted. In addition, as an example, the terminal may select a numerology (Numerology, e.g. SCS) to be used. In this case, as an example, the above-mentioned pneumatic roller may have parameters set through the control of the base station. In addition, as an example, one neuron may be arbitrarily determined according to a frequency used by the V2X sidelink communication, and is not limited to the above-described embodiment. In addition, as an example, the terminal may determine other additional information in advance before determining a source for the synchronous reference, and is not limited to the above-described embodiment.

Meanwhile, FIG. 6 may be an example of a scenario in which NR V2X sidelink communication is performed in a 3GPP network based on the above description. In this case, NR V2X sidelink communication may be performed on a 3GPP network (hereinafter, NG-RAN), and additionally, the presence of a GNSS signal may be considered.

More specifically, referring to FIG. 6, each of the NR V2X sidelink terminals may be an IC or OOC based on the NG-eNB 610. In addition, the case may be an IC or OOC based on the gNB 620. In addition, the case may be an IC or OOC based on the GNSS 630. In this case, in consideration of the above-described situation, the NR V2X sidelink terminals may select a source of a synchronization reference based on the location and capability of the terminal, which will be described later. In addition, as an example, in addition to the scenario as shown in FIG. 6, scenarios as shown in Table 10 may be considered and are not limited to the above-described embodiment.

TABLE 10

실시예 1(NR V2X 사이드링크 단말의 V2X 사이드링크 통신을 위한 주파수가 LTE/NR에 해당하는 3GPP 네트워크 상의 인커버리지(IC)인 경우)Embodiment 1 (when the frequency for V2X sidelink communication of an NR V2X sidelink terminal is incoverage (IC) on a 3GPP network corresponding to LTE / NR)

A case where the terminal for which V2X sidelink communication is triggered is a frequency for V2X sidelink communication may be considered. In this case, as an example, when the frequency for the V2X sidelink communication is an IC, it may mean that it is within at least one 3GPP network (e.g. LTE cell or NR cell) coverage.

In addition, as an example, a terminal for which V2X sidelink communication is triggered has a frequency for V2X sidelink communication, but is transmitted from at least one 3GPP network (eg, LTE cell or NR cell) on an RRC reconfiguration message or an associated serving cell / PCell. When the frequency for the corresponding V2X communication is included in the "v2x-InterFreqInfoList" in the system information, the following method may be applied in the same manner as in the case of the IC. In this case, as an example, the OOC may be a case where a frequency for V2X sidelink communication is not included in coverage of all 3GPP networks (e.g. LTE cell or NR cell). However, as described above, the UE is a system information transmitted on an RRC reset message or an associated serving cell / PCell, and the frequency for the corresponding V2X communication is included in the “v2x-InterFreqInfoList”, and the system information including the RRC reset message or Even when transmitted on the associated serving cell / PCell, the UE may operate in the same manner as in the case of incoverage.

In this case, the terminal may select a source of the synchronization reference based on the parameter for the synchronization type in the system information provided by the 3GPP network. For example, if the parameter for the synchronization type is "NR" in the system information provided by the 3GPP network, the terminal may select the NR cell as a source of the synchronization reference.

On the other hand, if the parameter for the synchronization type is "eNB" in the system information provided by the 3GPP network, the terminal may select the LTE cell as a source of the synchronization reference.

In addition, when the parameter for the synchronization type is "GNSS" in the system information provided by the 3GPP network, the terminal may select the GNSS cell as a source of the synchronization reference. That is, the source of the synchronization reference may be determined based on the parameter for the synchronization type in the system information provided by the 3GPP network.

In this case, as an example, a parameter regarding a synchronization type in system information of each of LTE / NR, which is a 3GPP network, may not be aligned. In this case, the terminal needs to determine the source of the synchronization reference, and a selection method for this may be necessary.

For example, the terminal may not expect to receive signaling for different synchronization type values from the LTE / NR cell. In this case, the terminal may ignore the signaling provided by the 3GPP network for the synchronization type and perform the same operation as the following case in which the synchronization type parameter is not provided or configured, which will be described later.

As another example, the terminal may receive different synchronization type information from the LTE / NR cell. In this case, the terminal may set one of the LTE or NR system information to follow first, and select a synchronization reference source based on the prior system information.

Also, as an example, a case in which the terminal is not provided with a parameter for the synchronization reference source may be considered. In this case, the terminal may determine whether to select the source of the synchronization reference as GNSS based on the reliability of the GNSS signal. More specifically, when the terminal is not provided with the parameter for the synchronization reference source, the terminal can determine the reliability of the GNSS signal. In this case, the reliability may be a signal strength of the GNSS signal as a threshold value. That is, if the signal strength of the GNSS signal is equal to or greater than the threshold value, it may be determined that the reliability of the signal is satisfied. In addition, as an example, the measurement of the reliability may be determined that the reliability is satisfied if the timing error value is less than or equal to the threshold value (e.g. 12 * Ts, Ts is the LTE / NR minimum time unit). In addition, as an example, the measurement of the reliability may be determined to be the reliability is satisfied if the frequency error value is less than or equal to the threshold value (e.g. ± 0.1PPM). Of course, it is not limited to the above-mentioned embodiment. At this time, if the reliability is satisfied based on the above, the terminal may select the GNSS as a source of the synchronization reference.

On the other hand, when the terminal is not provided with a parameter for the synchronization reference source, it may be considered that the reliability of the GNSS does not satisfy a certain criterion. In this case, the terminal may not select the GNSS as a source of the synchronization reference. For example, the UE may detect a SLSS signal having a specific SLSSID value (e.g. SLSSID = 0) corresponding to GNSS timing on a frequency for V2X sidelink communication. In this case, when the UE detects the corresponding SLSS signal, if the SLSS / PSBCH block RSRP value evaluated after the L3 filtering on the SLSS is higher than the minimum criterion for satisfying the reliability, the UE may refer to the corresponding SLSS as a reference synchronization. SyncRef UE) can be selected. Here, the L3 filtering refers to an operation of deriving one value through a cumulative weighted averaging operation by collecting samples of RSRP values received from the physical layer in a layer 3 (e.g. RRC layer) for a predetermined period. That is, when detecting the SLSS transmitted by another terminal receiving the GNSS timing and satisfying the reliability as described above, the terminal may select the transmitted terminal as a synchronous reference terminal.

However, the terminal may not detect the SLSS signal having a specific SLSSID value (e.g. SLSSID = 0) corresponding to the GNSS timing. That is, the terminal may not receive the SLSS transmitted from the terminal directly receiving the GNSS timing. In this case, the UE may select one of timing values of the LTE / NR cell corresponding to the 3GPP network, and at least one of the following embodiments may be selected.

실시예 1-1 (serving cell 기준)Example 1-1 (based on serving cell)

As described above, when the UE is not provided with the parameter for the synchronous reference source and does not satisfy the reliability of the GNSS, the UE does not detect the SLSS signal having a specific SLSSID value (eg SLSSID = 0) corresponding to the GNSS timing. The terminal may select a synchronization reference based on the serving cell. For example, the serving cell reference may refer to a cell that receives system information through a serving cell, a primary frequency, a secondary frequency, a PCell, or a SCell. That is, the terminal may select a synchronization reference source based on the cell receiving the system information. In this case, as an example, the UE may determine whether the LTE serving cell or the NR serving cell is based on the source receiving the system information.

In this case, when the UE is configured or received from the LTE cell (LTE serving cell, PCell or SCell), the configuration information associated with the frequency for V2X sidelink communication, if the UE is connected, the terminal uses the LTE cell timing as a reference source You can choose. On the other hand, if the UE is configured, received, or associated with the configuration information related to the frequency for V2X sidelink communication from the NR serving cell (NR serving cell, PCell or SCell), the UE uses the NR cell timing as a reference source. You can choose. That is, the terminal may select, as a reference source, a timing of a cell in which configuration information related to a frequency for V2X sidelink communication is set as a serving cell for receiving system information.

실시예 1-2(DL RSRP 세기 기준)Example 1-2 (Based on DL RSRP Strength)

As described above, when the UE is not provided with the parameter for the synchronous reference source and does not satisfy the reliability of the GNSS, the UE does not detect the SLSS signal having a specific SLSSID value (eg SLSSID = 0) corresponding to the GNSS timing. The terminal may select a synchronization reference based on downlink received signal received power (DL RSRP).

In this case, as an example, when a DL RSRP value is greater than a specific reference value set from an LTE cell associated with a frequency for V2X sidelink communication, the terminal may select the LTE cell timing as a reference source. In this case, the specific reference value may have a certain error as a threshold value.

In addition, as an example, when a DL RSRP value is greater than a specific reference value set from an NR cell associated with a frequency for V2X sidelink communication, the UE may select NR cell timing as a reference source.

In this case, as an example, it may be considered to receive a DL RSRP larger than a specific reference value set from both the LTE cell and the NR cell associated with the frequency for the V2X sidelink communication. In the above case, the terminal may compare the LTE DL RSRP and the NR DL RSRP. In this case, if the LTE_RSRP from the LTE cell associated with the frequency for V2X sidelink communication is larger than the NR_RSRP from the NR cell, the terminal may select the LTE cell timing as a reference source. On the other hand, if the LTE_RSRP from the LTE cell associated with the frequency for V2X sidelink communication is less than the NR_RSRP from the NR cell, the terminal may select the NR cell timing as a reference source. That is, if both the DL RSRP of the LTE cell and the DL RSRP of the NR cell are larger than a predetermined reference value, the synchronization reference source may be selected based on a large value compared with each other, as described above.

실시예 1-3(SCS 기준)Examples 1-3 (SCS Standards)

As described above, when the UE is not provided with the parameter for the synchronous reference source and does not satisfy the reliability of the GNSS, the UE does not detect the SLSS signal having a specific SLSSID value (eg SLSSID = 0) corresponding to the GNSS timing. The UE may select a synchronization reference source based on SCS (Subcarrier spacing). At this time, in the case of large SCS, time resolution may increase. In consideration of this, when the SCS value from the NR cell associated with the frequency for V2X sidelink communication is larger than LTE, the terminal may select the NR cell timing as a reference source. That is, as described above, if the timing of an NR cell providing a higher time resolution is selected as a synchronous reference source to efficiently correspond to a higher SCS value that can be utilized in NR V2X side communication, an efficient V2X sidelink radio resource. As efficiency can be provided, the UE can select NR cell timing as a reference source. Meanwhile, when the SCS value is equal to LTE from the NR cell associated with the frequency for V2X sidelink communication, the terminal may select the LTE cell timing as a synchronization reference source.

실시예 1-4(실시예 1-1 내지 실시예 1-3의 조합)Example 1-4 (combination of Examples 1-1 to 1-3)

As another example, a combination of the above-described embodiments 1-1 to 1-3 may be considered. For example, the source for the synchronization reference may be determined based on the proposed SCS value as in the above-described embodiments 1-3. That is, embodiments 1-3 may have the highest priority. Thereafter, if the SCS values are the same, the synchronization reference signal may be selected based on a cell having a large RSRP value as in the embodiment 1-2.

In addition, as an example, in Example 1-2, DL RSRP values of the LTE cell and the NR cell are first checked, and if all of the above values are larger than a specific reference value, the synchronization is performed based on the serving cell as in the embodiment 1-1. You can set the reference source. That is, Example 1-2 may take precedence over Example 1-1.

In addition, as an example, if the DL RSRP values of the LTE cell and the NR cell are first checked in Embodiment 1-2, and if all of the above values are larger than a specific reference value, the serving cell having a large SCS value is as in Embodiment 1-3. You can set the sync reference source based on this. That is, Example 1-2 may take precedence over Example 1-3.

Also, as an example, the priorities of Embodiments 1-1 to 1-3 may be set differently.

In addition, FIG. 7 may be a flowchart based on the above-described embodiments 1-1 to 1-3.

Referring to FIG. 7, when a frequency for V2X sidelink communication is incoverage, the terminal may select a synchronization reference source (S710). As described above, when the terminal receives a parameter for the synchronization reference source. In operation S720, the terminal may select a synchronization reference source based on the value set in the parameter. In operation S730, when the parameter for the synchronization reference source is not provided, it may be determined whether the reliability of the GNSS is satisfied. In this case, when reliability of the GNSS is satisfied (S750), the UE may select the GNSS as a synchronization reference source. On the other hand, when the reliability is not satisfied in the GNSS, it may be determined whether the SLSS signal having a specific SLSSID value corresponding to the GNSS timing may be detected. (S760) In this case, when the SLSS signal is detected, the terminal may detect the SLSS signal. A synchronous reference source can be selected based on (S770).

On the other hand, if the SLSS signal is not detected, the UE may select one of the timings of the LTE cell and the NR cell corresponding to the 3GPP network. (S780) That is, as described above, the UE may select a value for the synchronization reference source. In case the SLSS signal having a specific SLSSID value (eg SLSSID = 0) corresponding to the GNSS timing is not detected when the parameter is not provided and the reliability of the GNSS is not satisfied, the UE performs the above-described embodiments 1-1 to Based on the example 1-4, one of the timing of the LTE cell and the NR cell corresponding to the 3GPP network may be selected.

실시예 2(NR V2X 사이드링크 단말의 V2X 사이드링크 통신을 위한 주파수가 LTE/NR에 해당하는 3GPP 네트워크 상의 아웃오브커버리지(OOC)인 경우)Embodiment 2 (when the frequency for V2X sidelink communication of the NR V2X sidelink terminal is out of coverage (OOC) on the 3GPP network corresponding to LTE / NR)

The frequency for V2X sidelink communication of the V2X sidelink terminal may correspond to the OOC. In this case, as an example, the UE may search for all possible slots / symbols and all possible SLSSIDs at a frequency for V2X sidelink communication. That is, out of coverage on the network, the terminal may first search for all possible SLSSIDs in all possible slots / symbols at frequencies for V2X sidelink communication. In this case, when the SLSSID is not detected through the above search, the UE may perform the above-described operation at a frequency for another V2X sidelink communication.

For example, the UE may be a SL-SSB frequency position associated with another resource pool (e.g. SL-BWP) and transmitted on another frequency. Thereafter, the terminal may calculate the RSRP value of the SLSS corresponding to one or a plurality of SLSSIDs.

In this case, it may be considered that the UE has not selected one of the SyncRef UE and the GNSS as a synchronization reference source before. That is, the case of performing the initial selection can be considered. In this case, as an example, the terminal may receive a signal corresponding to one or a plurality of SLSSIDs. In case that the UE receives the RSRP value of the signals exceeding the set reference value and receives corresponding one or more SL-V2X-MIB information transmitted through the PSBCH channel or receives the reliable GNSS, the priority is as shown in Table 11 below. Synchronous reference sources can be selected based on the rank group. In this case, in Table 11, “Case 1” may be a case of acquiring a SLSS for NR timing from an in-device UE of an LTE / NR cell. In addition, “Case 2” may refer to a case in which a SLSS for NR timing is acquired from an in-coverage terminal of an LTE / NR cell, but is received from an OOC terminal. That is, the OOC terminal may be provided based on information obtained from the IC terminal.

In addition, “Case 3” may refer to a case of acquiring a SLSS for LTE timing from an in-device terminal of an LTE / NR cell. In addition, “Case 4” may refer to a case in which a SLSS for LTE timing is obtained from an in-coverage terminal of an LTE / NR cell, but is received from an OOC terminal. That is, the OOC terminal may be provided based on information obtained from the IC terminal.

In addition, “Case 5” may mean a case of obtaining GNSS timing directly from GNSS.

In addition, "Case 6" may mean a case of obtaining a SLSS for the GNSS timing from the UE within the discovery of the LTE / NR cell. In addition, “Case 7” may refer to a case where the SLSS for the GNSS timing is obtained from the UE in the discovery of the LTE / NR cell, but is received from the OOC terminal. That is, the OOC terminal may be provided based on information obtained from the IC terminal. In addition, “Case 8” may be a case where the GNSS timing is obtained from the OOC terminal and transmitted by the OOC terminal.

TABLE 11

In this case, the following embodiments may be performed based on the above-described Table 11, which will be described later.

실시예 2-1Example 2-1

In Embodiment 2-1, a SyncPriority value within a pre-configuration may be set based on “NG-RAN” and “GNSS” in which NR and LTE timing sources are combined as one priority. More specifically, in Table 11, the NR timing and the LTE timing source may be different from each other, but by integrating them into “NG-RAN”, a priority value may be set in a relationship with GNSS. That is, two may be defined in terms of SyncPriority parameters in the corresponding Preconfiguration. In consideration of the foregoing, in the following description, the reception of a SLSSID value having NG-RAN timing may mean a case in which the UE receives one or more SLSS signals having LTE cell or NR cell timing. have. For example, the terminal may receive one or more SLSS signals corresponding to the LTE cell timing or the NR cell timing from the V2X transmitting terminal present in the LTE cell or the NR cell. In this case, when the received signals have a RSRP value greater than or equal to the reference value, it may be determined that the received signals belong to the same priority group. At this time, in the following table may be a priority group presented based on the above.

For example, Table 12 may correspond to a case in which a SyncPriority order is set to “GNSS (1st)-> NG-RAN (2nd)” in a preconfiguration. That is, it may be a case where the GNSS timing takes precedence over the NG-RAN timing. For example, the above-described case may be the same as the case where the SyncPriority is set to “GNSS” in a preconfiguration. Meanwhile, the NG-RAN timing may be LTE cell or NR cell timing, as described above. At this time, referring to Table 12, the group receiving the GNSS timing directly from the GNSS may have the highest priority. In addition, the group for the case of obtaining the SLSS for the NG-RAN timing or the SLSS for the GNSS timing from the in-coverage terminals of the NG-RAN may have the same priority. Also, if the next priority is obtained from the SSSS for the NG-RAN timing or SLSS for the GNSS timing from the in-coverage terminals of the NG-RAN, but is received from the OOC terminal or the GNSS timing from the OOC terminal You can have the following priorities:

That is, based on Table 12, since the GNSS takes precedence over the NG-RAN, the case where the timing is directly received from the GNSS may be a top priority. Next, the case of receiving timing information from the in-coverage terminal of the NG-RAN may be the next priority, and the case of receiving timing information from the OOC terminal may be further subordinated.

TABLE 12

In addition, as an example, Table 13 may correspond to a case in which a SyncPriority order is set to “NG-RAN (1st)-> GNSS (2nd)” in a preconfiguration. That is, it may be the case that NG-RAN timing takes precedence over GNSS timing. In addition, as an example, the above-described case may be the same as the case where SyncPriority is set to “NG-RAN” in a preconfiguration. Meanwhile, the NG-RAN timing may be LTE cell or NR cell timing, as described above. At this time, referring to Table 13, the group for the case of obtaining the SLSS for the NG-RAN timing from in-coverage terminals of the NG-RAN may have the highest priority. Next, a group for the case where the SLSS for the NG-RAN timing is obtained from the in-coverage terminals of the NG-RAN but is received from the OOC terminal may be the next priority. Next, the group for the case of directly receiving timing from the GNSS may be the next priority. Next, the group for the case of obtaining the SLSS for the GNSS timing from the in-coverage terminals of the NG-RAN may be the next priority. Next, a group for the case where the SLSS for the GNSS timing is obtained from the in-coverage terminals of the NG-RAN but is received from the OOC terminal may be the next priority. Next, the case of obtaining the SLSS for the GNSS timing from the NG-RAN OOC terminal may be the next priority.

TABLE 13

실시예 2-2Example 2-2

In Example 2-2, it may be a method of limiting the number of methods for determining the priority, and Example 2-2-1 may be a case in which the method for determining the priority is limited to three cases. Example 2-2-2 may be a case of limiting six methods of determining priority.

More specifically, in the embodiment 2-2-1, the case where the group for the GNSS timing is the highest priority and the group for the LTE timing and the NR timing are equally subordinated can be considered. That is, similar to the embodiment 2-1, the GNSS and the eNB / NG may be compared. Of course, even if the eNB and the NR have the same priority, in the embodiment 2-2-1, the priorities of the groups for the GNSS timing, the LTE timing, and the NR timing can be compared. In addition, in the embodiment 2-2-1, three cases may be considered as the case where the eNB / NG takes precedence over the GNSS, the case where the eNB takes precedence over the NG, and the case where the NG takes precedence over the eNB.

Meanwhile, in 2-2-2, groups' priorities for GNSS timing, LTE timing, and NR timing may be compared, respectively. That is, the case based on the combination of three parameters can be derived, six cases can be considered, which will be described later.

실시예 2-2-1Example 2-2-1

In Embodiment 2-2-1, as described above, the method of determining the priority according to which parameter is set in advance may be a method of limiting to only three cases. That is, the priority group can be divided only in three possible cases. At this time, referring to Table 14 below, it may be the case that the SyncPriority order is set to "GNSS (1st)> eNB (2nd) = NR (2nd)" in the preconfiguration. For example, the above-described case may be the same as the case where SyncPriority is set to “GNSS” in a preconfiguration. Therefore, when the GNSS is set, the signal directly received from the GNSS may be given priority. At the same time, the LTE / NR / GNSS timing of the SLSSs transmitted within the network coverage may be prioritized next. Next, priority may be given to the LTE / NR / GNSS timing of the SLSSs transmitted out of network coverage, and finally, the non-SLSSs may belong to the last priority group, which is shown in Table 14.

TABLE 14

In addition, as an example, Table 15 may be a case in which a SyncPriority order is set to “NR (1st)-> eNB (2nd)-> GNSS (3rd)” in a preconfiguration. For example, the above-described case may be the same as the case where the SyncPriority is set to “NR” in a preconfiguration. Therefore, the group for the case of obtaining the SLSS for the NR timing from the LTE / NR coverage terminal may be prioritized. Next, the group for the case of obtaining the SLSS for the LTE timing from the LTE / NR incovery terminal may be prioritized next. Next, the group for the case of receiving the SLSS for the NR timing from the LTE / NR in-coverage terminal but from the OOC terminal may be prioritized next. Next, the group for the case of receiving the SLSS for the LTE timing from the LTE / NR in-coverage terminal but from the OOC terminal may be prioritized next. Next, the group for the case of obtaining the SLSS for the GNSS timing from the LTE / NR incovery terminal may be prioritized next. Next, the group for the case of receiving the SLSS for the GNSS timing from the LTE / NR in-coverage terminal but from the OOC terminal may be prioritized next. Next, the group for the case of receiving the SLSS for the GNSS timing from the OOC terminal may be prioritized next.

TABLE 15

In addition, as an example, Table 16 may correspond to a case in which a SyncPriority order is set to “eNB (1st)-> NR (2nd)-> GNSS (3rd)” in a preconfiguration. For example, the above-described case may be the same as the case where SyncPriority is set to “eNB” in a preconfiguration. Therefore, the group for the case of obtaining the SLSS for the LTE timing from the LTE / NR coverage terminal may be prioritized. Next, the group for the case of obtaining the SLSS for the NR timing from the LTE / NR coverage terminal may be prioritized next. Next, the group for the case of receiving the SLSS for the LTE timing from the LTE / NR in-coverage terminal but from the OOC terminal may be prioritized next. Next, the group for the case of receiving the SLSS for the NR timing from the LTE / NR in-coverage terminal but from the OOC terminal may be prioritized next. Next, the group for the case of obtaining the SLSS for the GNSS timing from the LTE / NR incovery terminal may be prioritized next. Next, the group for the case of receiving the SLSS for the GNSS timing from the LTE / NR in-coverage terminal but from the OOC terminal may be prioritized next. Next, the group for the case of receiving the SLSS for the GNSS timing from the OOC terminal may be prioritized next.

TABLE 16

Example 2-2-2

As described above, the embodiment 2-2-2 may be an embodiment considering all six cases of the method of determining the priority according to which parameter is preset in the preconfiguration (GNSS timing, LTE timing and NG timings respectively). That is, unlike the embodiment 2-2-1, the priority group can be divided for all six possible combinations.

In this case, as an example, Table 17 may correspond to a case in which a SyncPriority order is set to “GNSS (1st)-> eNB (2nd)-> NR (3rd)” in a preconfiguration. Therefore, when the GNSS is set, the signal directly received from the GNSS can be given priority. Next, of the SLSSs transmitted within the network coverage, the SLSS having the LTE timing may have the next priority. Next, the SLSS with NR timing may have the next priority. Next, the SLSS with GNSS timing may have the next priority. Next, of the SLSS transmitted out of network coverage, the SLSS having the LTE timing may have the next priority. Next, the SLSS with NR timing may have the next priority. Next, the SLSS with GNSS timing may have the next priority. Finally, the other SLSSs belong to the last priority group, as shown in Table 17 below.

TABLE 17

Next, when the SyncPriority order is set to “GNSS (1st)-> NR (2nd)-> eNB (3rd)” in Preconfiguration, it may be as shown in Table 18 below. In this case, Table 18 may be similar to Table 17, only the priority of the LTE timing and NR timing can be changed, the specific configuration is shown in Table 18 below.

TABLE 18

Next, when the SyncPriority order is set to “NR (1st)-> eNB (2nd)-> GNSS (3rd)” in Preconfiguration, it may be as shown in Table 19 below.

TABLE 19

Next, when the SyncPriority order is set to “eNB (1st)-> NR (2nd)-> GNSS (3rd)” in Preconfiguration, it may be as shown in Table 20 below.

TABLE 20

Next, when the SyncPriority order is set to “NR (1st)-> GNSS (2nd)-> eNB (3rd)” in the preconfiguration, it may be as shown in Table 21 below.

TABLE 21

Next, when the SyncPriority order is set to “eNB (1st)-> GNSS (2nd)-> NR (3rd)” in the preconfiguration, it may be as shown in Table 22 below.

TABLE 22

8 is a flowchart in consideration of Example 2-2 (2-2-1 and 2-2-2).

Referring to FIG. 8, when the frequency for V2X sidelink communication is out of coverage (OOC), the terminal may select a synchronization reference source. In this case, in case of OOC, the UE may determine a priority method based on a preset parameter in a preconfiguration. In this case, as an example, the priority method may be determined by limiting to only three cases as in the embodiment 2-2-1. That is, the GNSS timing and the LTE timing / NR timing are compared as in the above-described embodiment 2-2-1, so that the method may be limited as in the above-described embodiment. In addition, as an example, all six cases may be considered as in Example 2-2-2. That is, all possible combinations may be considered based on each of GNSS timing, LTE timing, and NR timing. Thereafter, the terminal may select the synchronization reference source through the priority based on the SyncPriority order in the preconfiguration, and the detailed method is as described above. (S830)

Meanwhile, as an example, whether a priority is determined based on any of the above-described embodiments 2-2-1 or 2-2-2 may be preset. That is, the terminal may support the above-described embodiments 2-2-1 and 2-2-2, but may determine the priority based on any one of the above-described methods based on a preset value. However, it is not limited to the Example mentioned above.

실시예 3(NR V2X 사이드링크 단말의 V2X 사이드링크 통신을 위한 주파수가 LTE/NR에 해당하는 3GPP 네트워크 상의 아웃오브커버리지(OOC)인 경우)Embodiment 3 (when the frequency for V2X sidelink communication of the NR V2X sidelink terminal is out of coverage (OOC) on the 3GPP network corresponding to LTE / NR)

The third embodiment may be an embodiment of a case where the frequency for V2X sidelink communication of the UE is OOC on a 3GPP network corresponding to LTE / NR, as in the second embodiment. In this case, as an example, a priority group in each sync reference source may be defined. The priority between the three defined groups may be indicated by defining a SyncPriority order parameter in a preconfiguration. In this case, as an example, the SyncPriority order parameter may determine only the priority for each group. For example, when the SyncPriority order is set to “NR (1st)-> eNB (2nd)-> GNSS (3rd)” in Preconfiguration, the priority between the groups is shown in Table 23 and Table. 24 and Table 25. In addition, as an example, the rankings within the groups may be all the same, and are not limited to the above-described embodiment.

TABLE 23

TABLE 24

TABLE 25

In addition, as an example, when the SyncPriority order in the Preconfiguration is set to “NR (1st)-> GNSS (2nd)-> eNB (3rd)”, the priority between the respective groups is shown in Table 26. , Table 27 and Table 28 can be determined as. In addition, as an example, the rankings within the groups may be all the same, and are not limited to the above-described embodiment.

TABLE 26

TABLE 27

TABLE 28

Also, as an example, when the SyncPriority order is set to “GNSS (1st)-> eNB (2nd)-> NR (3rd)” in Preconfiguration, it is based on the aforementioned Tables 26 to 28. The priority may be set as shown in Table 29 below.

TABLE 29

Also, as an example, when the SyncPriority order is set to “GNSS (1st)-> NR (2nd)-> eNB (3rd)” in Preconfiguration, it is based on the aforementioned Tables 26 to 28. The priority may be set as shown in Table 30 below.

TABLE 30

In addition, as an example, when the SyncPriority order is set to “eNB (1st)-> GNSS (2nd)-> NR (3rd)” in the Preconfiguration, it is based on the aforementioned Tables 26 to 28. The priority may be set as shown in Table 31 below.

Table 31

In addition, as an example, when the SyncPriority order is set to “eNB (1st)-> NR (2nd)-> GNSS (3rd)” in Preconfiguration, it is based on the aforementioned Tables 26 to 28. The priority may be set as shown in Table 32 below.

Table 32

That is, a priority group among GNSS timing, LTE timing, and NR timing may be determined based on a SyncPriority order in a preconfiguration, and the priority may be determined again within the group. It is not limited to.

실시예 4(추가 우선 순위 결정 방법)Example 4 (Additional Priority Determination Method)

In addition, as an example, in the second to third embodiments, when a plurality of signals for a synchronization reference source exist within the same priority group, priority may be additionally determined among the plurality of signals. In particular, when the SLSSIDs corresponding to the LTE timing and the NR timing are received (NG-RAN timing), prioritization between the two may be performed by the terminal. In this case, as an example, the comparison of the plurality of signals may determine the reference source by comparing the "RSRP value" or "RSRP value and SCS value" of the signals from the two received sources.

More specifically, the “RSRP value” comparison method compares an RSRP value corresponding to a reception sensitivity of a signal from two sources corresponding to LTE timing and NR timing, which is equal to or greater than a predetermined reference value (a constant value for minimum requirements). 3GPP network timing with a larger value among the signals may be used, and may be similar to Embodiment 1. FIG.

Alternatively, the method of comparing “RSRP value and SCS value” compares an RSRP value corresponding to a reception sensitivity of a signal from two sources corresponding to LTE timing and NR timing, which is equal to or greater than a predetermined reference value (a constant value for minimum requirements). Among the signals, 3GPP network timing with a larger SCS value may be used. This is because the timing of NR cells that can set 30, 60, 120, 240 kHz SCS in addition to 15 kHz SCS may have a higher time resolution than LTE cell timing based on only 15 kHz SCS, which is an embodiment. May be similar to one. That is, the transmission and reception timing for the NR V2X sidelink transmission and reception can be finely adjusted to provide advantages in terms of resource utilization and compatibility with the NR SL.

실시예 5(동기 참조 소스 재선택)Example 5 (Synchronous Reference Source Reselection)

As another example, the terminal selecting the synchronization reference source at least once based on the above description may perform an operation for reselecting the synchronization reference source.

In more detail, in the OOC case, the case in which the terminal which has already selected the synchronization reference source once selected the one synchronization reference terminal (SyncRef UE) may be considered. At this time, as an example, another RSRP value (candidate SyncRef UE) is equal to or greater than a predetermined reference value (a constant value for minimum requirement), and another RSRP value (candidate SyncRef UE) has the same priority as the current SyncRef UE. Consider the case of belonging to a group. At this time, if another RSRP value (candidate SyncRef UE) is greater than a preset value (a constant value for minimum requirement) than the RSRP value of the current syncRef UE, the synchronization source for the current sync reference UE will not be selected. Can be. That is, based on the above conditions, if there is a signal corresponding to the highest priority group among the SyncRef UEs, the SyncRef UE may be selected.

Also, as an example, if another RSRP value (candidate SyncRef UE) is greater than or equal to a preset reference value (a constant value for minimum requirement), and the other RSRP value (candidate SyncRef UE) belongs to a higher priority group, refer to current synchronization. The synchronization source for the terminal may not be selected. That is, based on the above conditions, if there is a signal corresponding to the highest priority group among the SyncRef UEs, the SyncRef UE may be selected.

For example, when the reliability of the GNSS signal is equal to or greater than a predetermined reference value (a constant value for the minimum requirement), and the GNSS belongs to a higher priority group than the current sync reference UE (SyncRef UE), You may not select a sync source. That is, based on the above conditions, if there is a signal corresponding to the highest priority group among the SyncRef UEs, the SyncRef UE may be selected.

Also, as an example, when the RSRP value of the current SyncRef UE is equal to or less than a predetermined reference value (a constant value for the minimum requirement), the synchronization source for the current sync reference terminal may not be selected. That is, based on the above conditions, if there is a signal corresponding to the highest priority group among the SyncRef UEs, the SyncRef UE may be selected.

Also, as an example, a case in which the UE selects GNSS may be considered.

At this time, if another RSRP value (candidate SyncRef UE) is greater than or equal to a preset reference value (a constant value for minimum requirement) and the candidate reference terminal (candidate SyncRef UE) belongs to a higher priority group than GNSS, the corresponding GNSS is not selected. You may not. For example, even when the reliability of the GNSS signal is lower than a predetermined reference value (a constant value for the minimum requirement), the corresponding GNSS may not be selected and is not limited to the above-described embodiment.

Meanwhile, FIG. 9 may be an example of a scenario in which NR V2X sidelink communication is performed in a 3GPP network based on the above description. In this case, NR V2X sidelink communication may be performed on a 3GPP network (hereinafter, NG-RAN), and additionally, the presence of a GNSS signal may be considered.

More specifically, referring to FIG. 9, each of the NR V2X sidelink terminals may be an IC or OOC based on the NG-eNB 910. In addition, the case may be an IC or OOC based on the gNB 920. In addition, the case may be an IC or OOC based on the GNSS 930. In this case, in consideration of the above-described situation, the NR V2X sidelink terminals may select a source of a synchronization reference based on the location and capability of the terminal, which will be described later. In addition, as an example, in addition to the scenario as shown in FIG. 9, scenarios as shown in Table 33 may be considered and are not limited to the above-described embodiment.

Table 33

실시예 (NR SL-SSB 물리 자원 위치 지정 방법)Embodiment (NR SL-SSB Physical Resource Positioning Method)

As the NR SL-SSB physical resource location designation method, the NR SL-SSB resource location may be indicated in terms of frequency domain. In addition, as an example, the NR SL-SSB resource location may be indicated from a time domain perspective as an NR SL-SSB physical resource location designation method. As another example, the NR SL-SSB physical resource location may be indicated through additional signaling in addition to the indication information in the above-described frequency domain and time domain view, and is not limited to the above-described embodiment.

실시예 6(주파수 도메인 관점)Example 6 (Frequency Domain Perspective)

Unlike LTE sidelinks, NR sidelinks can operate in ultra-wideband. In this case, for example, in the LTE sidelink, the SLSS / PSBCH may be transmitted in a plurality of physical resource blocks (PRBs) among uplink carriers. However, as described above, the SLSS / PSBCH may not be transmitted only at a specific frequency position of one frequency (or carrier) according to the characteristics of the NR band which is an ultra wide band. That is, in one uplink carrier (or frequency), one or more sidelink BWPs (SL BWPs) may be configured in the form of a resource pool for NR sidelink communication. In this case, as an example, the NR SL-SSB may be transmitted corresponding to one or a plurality of SL BWPs.

More specifically, FIG. 10 below illustrates a BWP configuration associated with cell connection of an NR Uu link. Referring to FIG. 10, an NR carrier may have at least one cell-defining SSB (hereinafter referred to as C-SSB). For example, in FIG. 10, SSB 1 and SSB3 may be C-SSBs. In this case, each C-SSB may be associated with a Remaining System Information (RSI) (i.e.SIB1). The RMSI may include signals and information that must be provided by the NR base station essential to configure one cell. In addition, the C-SSB may always be located on a sync raster. In addition, as an example, in the RRC CONNECTED mode, additional SSBs may be set based on a measurement purpose. In this case, as an example, the initial access terminals may select and receive an optimal C-SSB through a sync raster search within a specific NR band. In this case, by decoding the RMSI associated with the received C-SSB, the initial cell access may be performed starting with a random access procedure. For example, UE 1 (UE 1, 1010) and UE 2 (UE 2, 1020) may receive SSB 1, decode RMSI associated with SSB 1, and perform initial cell access based on a random access procedure. Also, as an example, UE 3 (UE 3, 1030) may receive SSB 2, decode RMSI associated with SSB 2, and perform initial cell access based on a random access procedure. That is, gNB cell configuration may be possible using the same or different Cell ID in one carrier. In addition, frequency utilization using BWP may be possible on one carrier.

Also, for example, system information (e.g. SIB21 in case of LTE V2X) may be provided from a cell in performing NR V2X sidelink communication. At this time, in the NR, system information may be provided through a Sidelink-Other System Information (SL-OSI) channel. However, as an example, the system information may be transmitted through the NR PSBCH or the RMSI according to the signaling method without being limited to the SL-OSI channel. In the following description, for the sake of convenience, S-OSI is described as a reference, but it may be obvious that the same may be applied to NR PSBCH or RMSI.

In this case, for example, information on basic resource pool information setting for NR V2X communication and setting for transmission of synchronization information may be provided in the SL-OSI information. In addition, other configuration information for NR V2X communication may also be provided, and is not limited to the above-described embodiment.

In this case, as an example, the following configuration information for transmission of synchronization information may be provided to all of idle / inactive / connected mode terminals through the SL-OSI provided in one cell. For example, the terminal that is not provided with the corresponding system information may be provided with the configuration information related to the above-described synchronization information transmission in the pre-configuration information, it is not limited to the above-described embodiment.

Meanwhile, FIG. 11 is a diagram illustrating a relationship between a resource pool and a SLSS / PSBCH block. Referring to FIG. 11, a SLSS / PSBCH block may be associated with a resource pool. For example, one resource pool or a resource pool list may be associated with a SLSS / PSBCH block that provides one or more SLSSID values. For example, when one resource pool is associated with one SLSS / PSBCH block having a SLSSID value, the corresponding SLSS / PSBCH block may exist in the corresponding resource pool. As another example, one resource pool may be associated with a plurality of SLSS / PSBCH blocks having a SLSSID value. In this case, the plurality of SLSS / PSBCH blocks may exist in the corresponding resource pool, and is not limited to the above-described embodiment.

In this case, as an example, FIG. 12 is a diagram illustrating a method for indicating NR side link resource pool and SL-SSB configuration using system information (e.g. SL-OSI) provided for each cell. 12 is a diagram illustrating a case where a supplementary uplink (SUL) band exists in an NR frequency division duplex (FDD). In this case, the SUL may refer to an extra UL carrier that can be additionally set to a DL carrier or a DL / UL carrier that can configure one serving cell.

For example, the base station may provide V2X synchronization information setting and resource pool setting in the corresponding cell through system information (e.g. RMSI or OSI). In this case, the terminal may receive the C-SSB on the DL carrier to obtain the above-described system information. The terminal may receive the above-described configuration information for V2X communication from the selected serving cell through system information.

More specifically, referring to FIG. 12, the

first terminals UE

1 and 1210 and the

second terminals UE

2 and 1220 are terminals that camp on on Cell ID = 5 to receive OSI information. Can be. On the other hand, the

third terminals UE

3 and 1230 may be terminals that camp on the Cell ID = 6 and receive other OSI information. That is, the first terminal 1210 / the second terminal 1220 and the third terminal 1230 can be seen as camping on different cells, it can be seen as a case of different cells. In this case, each cell is scrambled to SI-RNTI on “Type0 CORESET” in different initial downlink BWPs (SIWs) and SIB1 (ie RMSI) may be provided to terminals in each cell.

UEs in the cell receiving the SIB1 may obtain “OSI CORESET” information and scheduling information for receiving OSI information and may receive OSI based on the indicated OSI scheduling information.

In this case, in FIG. 12, UEs that acquire independent OSI information for each cell may receive cell specific RRC parameters for NR V2X communication. For example, at Cell ID = 5, the OSI may provide resource pool information associated with a location on a frequency of the first SL-SSB 840. Also, as an example, the OSI corresponding to Cell ID = 6 may provide resource pool information associated with a location on frequencies of the second SL-SSBs 850-1 and 850-2.

That is, in the above mentioned NR V2X sidelink communication, a position capable of transmitting / receiving SL-SSB is not previously determined, and may fluctuate depending on a resource pool setting associated with a frequency band. There is a need to provide information. That is, in NR V2X sidelink communication, a location capable of transmitting / receiving SL-SSB may be differently set according to a setting of an operator providing a V2X sidelink communication service. Therefore, corresponding location information needs to be provided to terminals. Accordingly, the OSI information may provide at least one NR SL-SSB frequency position and resource pool list information associated with the corresponding NR SL-SSB as parameters for NR V2X communication.

Also, as an example, NR TDD (Time Division Duplex) may be considered. In this case, as an example, in NR TDD, DL and UL may operate while having the same BWP index. That is, the same BWP setting may be applied to the DL and the UP. In this case, FIG. 13 is a diagram illustrating the operation in the NR TDD band in consideration of the above description. Referring to FIG. 13, although similar to FIG. 12, DL and UL operate while having the same BWP index, SL-SSBs may correspond to one resource pool, and the operation of providing information is illustrated in FIG. 12. May be similar to

실시예 6-1(NR 기지국에서 NR V2X 단말에게 NR SL-SSB 물리자원의 위치를 제공하는 경우)Example 6-1 (when NR base station provides location of NR SL-SSB physical resource to NR V2X terminal)

Based on the above, the NR base station may provide the location of the NR SL-SSB physical resource to the NR V2X terminal. In this case, as an example, the NR SL-SSB frequency information provided by the base station may mainly be a carrier corresponding to FDD or SUL. At this time, a specific frequency position indicating method will be described below. For example, the information on the synchronization information transmission setting about the NR SL-SSB transmission information may include one or a plurality of NR SL-SSB transmissions in the UL carrier and is not limited to the above-described embodiment.

실시예 6-1-1 (NR 기지국 시그널링 정보 이용)Example 6-1-1 (using NR base station signaling information)

For example, when the NR V2X terminal initially accesses the NR base station, the NR V2X terminal may receive system information from the NR base station. In this case, the system information may include setting information for synchronization. The following describes a specific method for indicating the frequency position of the NR SL-SSB.

실시예 6-1-1-1(“ARFCN-ValueNR” 또는 “GSCN”를 통해 NR SL-SSB 주파수 위치 지시)Example 6-1-1-1 (Indication of NR SL-SSB Frequency Location via “ARFCN-ValueNR” or “GSCN”)

For example, the NR base station may indicate the NR SL-SSB frequency position through “ARFCN-ValueNR” or “GSCN”.

In this case, the “ARFCN-ValueNR” value may be a value corresponding to a channel raster in all bands defined by NR. Therefore, knowing the value can indicate the position of a particular channel raster (band raster) in a particular band. At this time, the position of the frequency indicated by the “ARFCN-ValueNR” value is determined by the smallest subcarrier index of the center PRB of the NR SL-SSB (eg subcarrier # 0 of RB # 10 of NR-SL SSB (NR-SL). SSB total PRB number 20)). Also, for example, the frequency position may be determined as the lowest subcarrier index (Subcarrier # 0 of the PRB # 0) of the lowest PRB index (PRB # 0 of NR SL SSB) to which the NR SL-SSB is allocated. As another example, another subcarrier index of another PRB to which the NR SL-SSB is allocated may be used, and is not limited to the above-described embodiment.

In addition, the NR base station may indicate the NR SL-SSB frequency position through a "GSCN (Global Synchronization Channel Number)" value. In this case, since the GSCN value instructed by the UE is allocated one-to-one to a specific sync raster position of a specific band, the GSCN value may indicate the NR SL-SSB frequency position through the value. Like the “ARFCN” value, the indicated frequency position is the smallest subcarrier index of the center PRB of the NR SL-SSB (eg subcarrier # 0 of RB # 10 of NR-SL SSB (when the total number of PRBs in the NR-SL SSB is 20). Can be determined. Also, for example, the frequency position may be determined as the lowest subcarrier index (Subcarrier # 0 of the PRB # 0) of the lowest PRB index (PRB # 0 of NR SL SSB) to which the NR SL-SSB is allocated. As another example, another subcarrier index of another PRB to which the NR SL-SSB is allocated may be used, and is not limited to the above-described embodiment.

In addition, as an example, an additional NR-SL SSB subcarrier offset signaling may be additionally indicated to the above two signaling (“ARFCN-ValueNR” or “GSCN”) to indicate a frequency position that fits the UL PRB boundary. . In this case, the subcarrier offset value between the UL PRB and the frequency position indicated by the "ARFCN" or "GSCN" value may be provided to the UE through signaling. The terminal may check the information on the UL PRB boundary and may provide PRB information for V2X sidelink transmission and reception.

실시예 6-1-1-2(FrequencyInfoUL 내의 absoluteFrequencyPointA 값이 지시하는 UL 캐리어를 위한 Point A 위치에 상대적인 오프셋 값을 제공하여 NR SL-SSB 주파수 위치 지시)Example 6-1-1-2 (NR SL-SSB frequency position indication by providing an offset value relative to the Point A position for the UL carrier indicated by the absoluteFrequencyPointA value in the FrequencyInfoUL)

As another example, the smallest subcarrier index (eg subcarrier # 0 of RB # 10 of NR−) of the center PRB of the NR SL-SSB may be provided by providing an offset value relative to the “Point A” position for the UL carrier provided by the base station. The terminal may indicate the SL SSB (when the total number of PRBs of the NR-SL SSB is 20.) In this case, “Point A” may be information about a start position in a provided UL carrier, and thus, relative to “Point A”. In addition, the frequency position may be determined by providing an offset value, and, for example, the frequency position may be the lowest subcarrier index (Subcarrier # 0) of the lowest PRB index (PRB # 0 of NR SL SSB) to which the NR SL-SSB is allocated. of the PRB # 0. As another example, another subcarrier index of another PRB to which the NR SL-SSB is allocated may be used, and is not limited to the above-described embodiment.

As another example, the aforementioned offset value may be indicated by using the number of PRBs derived based on a specific subcarrier spacing value for each frequency band.

More specifically, the number of PRBs can be determined based on the reference SCS (Reference SCS) as FR1 of 6 GHz or less, and can be indicated based on this. As an example, the case where the reference SCS is 15 kHz may be considered. In addition, the smallest value among the SCSs that can be supported in the NR SL frequency band existing within the FR1 frequency range may be the reference SCS. For example, when the SCSs defined for each NR sidelink frequency band in FR1 are any of 30 kHz, 60 kHz, or (30 kHz and 60 kHz) SCSs, the smallest value 30 kHz may be determined as the reference SCS. In this case, as described above, the offset may be indicated in consideration of the number of PRBs determined based on the reference SCS.

Also, as an example, the reference SCS may be 60 kHz in FR2, which is greater than 6 GHz. In this case, the PRB may be determined based on the reference SCS, and the offset may be indicated in consideration of the number of PRBs determined based on the reference SCS and is not limited to the above-described embodiment.

실시예 6-1-1-3(UL 캐리어의 “Transmission BW”의 시작에 상대적인 오프셋 값을 통해서 NR SL-SSB 주파수 위치 지시)Example 6-1-1-3 (Indication of NR SL-SSB Frequency Position Through Offset Value Relative to Start of “Transmission BW” of UL Carrier)

As another example, the NR SL-SSB frequency position may be indicated through a relative offset value with respect to a start position of a transmission bandwidth of a UL carrier.

14 is a diagram illustrating how an NR SL-SSB frequency position is indicated based on a start position of a transmission bandwidth.

In more detail, referring to FIG. 14, frequency information on a UL carrier may be provided with information on start-to-carrier information, bandwidth (carrierBandwith) information, and SCS value of available frequency resources. At this time, from the above-described information can be used in the actual data transmission from the UL frequency resources that are separated by "offsetToCarrier" compared to "Point A". For example, a CRB (Common Resource Block) for initial access may be transmitted from a frequency point “Point A” to “offsetToCarrier”, and the actual NR Uu / SL transmits data from “Point A” to “OffsetToCarrier”. It can be used from the position after the distant frequency position. Therefore, as a scheme for indicating the position of the NR SL-SSB, it may be derived and indicated based on the above-described information.

In detail, the NR SL-SSB location may indicate the corresponding NR SL-SSB frequency location through additional offset (OffsetToSLSSB # 1 and offsetToSLSSB # 2) values from the time when the transmission bandwidth (BW) of the UL carrier starts. That is, the offset value for each SL-SSB block may be calculated from a time point at which the transmission BW of the UL carrier starts to indicate a frequency position for each SL-SSB block.

In addition, an additional offset “offsetToSLSSB” may be indicated with the number of PRBs. In this case, the SCS derived from the number of PRBs may be the SCS of the UL carrier or the SCS of the NR SL-SSB, which is not limited to the above-described embodiment.

실시예 6-1-1-4(랜덤 엑세스 수행을 위해 정의한 “Initial UL active BWP”의 시작에 상대적인 오프셋 값을 통해서 NR SL-SSB 주파수 위치 지시)Example 6-1-1-4 (Indicating NR SL-SSB Frequency Position Through Offset Value Relative to Start of “Initial UL Active BWP” Defined for Performing Random Access)

As another example, the NR base station may indicate the NR SL-SSB frequency position through an offset value relative to the start of “Initial UL active BWP” defined for performing random access. In this case, as an example, when the UE checks the NR SL-SSB frequency position, information included in the SL-OSI may be used. At this time, the RMSI (SIB1) may be transmitted earlier than the SL-OSI, and the terminal position may check the frequency position information faster when checking the NR SL-SSB frequency position through the RMSI (SIB1). In consideration of the foregoing, information on “initial UL active BWP” provided by the RMSI (SIB1) may be used for indicating the NR SL-SSB frequency position. That is, based on the initial UL activation BW can provide a relative offset value at the frequency started by the corresponding BWP to indicate the NR SL-SSB position, through which the terminal can quickly indicate the frequency position of the NR SL-SSB. . In addition, as an example, the frequency position of the NR SL-SSB may be indicated through a relative offset or an additional offset “offsetToSLSSB”. Meanwhile, as an example, the relative offset or the additional offset “offsetToSLSSB” may be indicated based on the number of PRBs. In this case, the SCS based on the determination of the number of PRBs may be SCS of UL carrier or Initial UL active BWP SCS (e.g. Msg. 1 SCS or Msg. 3 SCS), which is not limited to the above-described embodiment.

실시예 6-1-1-5(NR 사이드링크 자원 풀 시작 (subcarrier#0 of PRB#0)에 상대적인 오프셋 값을 통해서 NR SL-SSB 주파수 위치 지시)Example 6-1-1-5 (Indication of NR SL-SSB Frequency Location through Offset Value Relative to NR Sidelink Resource Pool Start (subcarrier # 0 of PRB # 0))

As another example, the base station may indicate the NR SL-SSB frequency position through a relative offset value at the start of the NR sidelink resource pool. FIG. 15 illustrates a method of indicating an NR SL-SSB frequency position based on an NR sidelink resource pool. FIG.

In more detail, the NR base station may provide the terminal with information on the sidelink resource pool as well as configuration information for transmitting synchronization information through the NR SL OSI. In this case, configuration information for transmission of synchronization information for NR SL-SSB transmission associated with the resource pool list in the NR SL OSI may be provided. In this case, at least one resource pool may be associated with a specific SL-SSB, and the base station may provide synchronization information configuration information associated with the resource pool to the terminal. Therefore, by providing an additional offset value to the UE in a specific frequency position (eg subcarrier # 0 of PRB # 0 for a NR SL resource pool / pool list) of each NR sidelink resource pool, the UE provides an NR SL associated with the corresponding resource pool. You can check the SSB frequency position. For example, referring to FIG. 15, an offset value may be indicated based on the start position of “SL resource pool # 1”. For example, a start position of “SL resource pool # 1” may be determined based on “subcarrier # 0 of PRB # 0 for a NR SL resource pool 1”. At this time, the SL-SSB # 1 as the SL-SSB associated with the “SL resource pool # 1” may be indicated by the additional offset value offsetOffSLSSB # 1. Similarly, the start position of “SL resource pool # 2” may be determined based on “subcarrier # 0 of PRB # 0 for a NR SL resource pool 2”. In this case, the SL-SSB # 2 as the SL-SSB associated with the “SL resource pool # 2” may be indicated by the additional offset value offsetOffSLSSB # 2. Meanwhile, similarly to the above-described embodiments, the relative offset or the additional offset “offsetToSLSSB” may be indicated based on the number of PRBs. In this case, the SCS based on the PRB number determination may be determined based on the SCS set in the corresponding resource pool, and is not limited to the above-described embodiment.

In addition, as an example, the aforementioned signaling may be indicated in units of a number of PRBs or a plurality of PRBs (e.g. subchannel). In this case, the subchannel may be a frequency resource that can be defined and used in a minimum data scheduling unit set for each resource pool.

실시예 6-1-2(RRC 연결 모드 단말의 경우)Example 6-1-2 (In case of RRC connected mode terminal)

As another example, the case in which the UE is in an RRC connected mode may be considered. In this case, the UE may be provided with the information on the above-described embodiments 6-1-1-1 to 6-1-1-5 through the RRC reset message. That is, the terminal may obtain the above information through the RRC reset message. In this case, the RRC connected mode terminal may add the NR SL-SSB based on the information received through the RRC reconfiguration message from the location information on the NR SL-SSB frequency provided through the OSI. In addition, as an example, the RRC connected mode UE resets (or overwrites) new NR SL-SSBs based on information received through an RRC reset message from location information on the NR SL-SSB frequency provided through OSI. can do.

For example, the terminal may receive one NR SL-SSB # 1 through the system information of the NG-RAN and operate in an idle / inactive mode. Subsequently, when the terminal is switched to the RRC connected mode to operate, NR SL-SSB # 2 is additionally set in the terminal to improve reliability in detecting the synchronization information reference source and timing. Accordingly, the terminal provided with the corresponding configuration may receive a plurality of SL-SSBs each having a plurality of SLSSID values. In this case, the terminal may assume that the plurality of SL-SSBs provide the same synchronization source and timing value. In addition, as an example, when the UE does not further receive quasi co-located (QCL) related signaling, the UE may assume that a plurality of SL-SSBs are quasi-co located with each other, and are not limited to the above-described embodiment. Do not.

In this case, as an example, when two or more SL-SSBs are configured in one terminal and related QCL configuration is provided, the terminal may determine a timing value and an RSRP value through the SL-SSB based on the QCL type based on the provided QCL configuration. It can be measured. In this case, the QCL may mean that the UE assumes that the SLSS and / or PSBCH DMRSs in the plurality of SL-SSBs are quasi co-located with each other in terms of Doppler shift, Doppler spread, average delay, delay spread, and spatial Rx parameter. .

실시예 6-1-3(OOC 단말의 경우(Pre-configuration의 경우))Example 6-1-3 (In case of OOC terminal (in case of pre-configuration))

As another example, the case where the terminal exists outside the NG-RAN base station coverage may be considered. That is, the terminal existing in out-of-coverage may be provided based on the preset information if the terminal does not receive the system information in advance. For example, the preset information may be provided to the terminal including the signaling method for the above-described embodiments 6-1-1-1 to 6-1-1-5, and is limited to the above-described embodiment. It doesn't work.

실시예 6-2(ng-eNB (E-UTRA) 기지국에서 NR V2X 단말에게 NR SL-SSB 물리자원의 위치를 제공하는 경우)Example 6-2 (when ng-eNB (E-UTRA) base station provides the location of NR SL-SSB physical resource to NR V2X terminal)

As another example, in the above-described embodiment 6-1, the case in which the NR base station indicates the frequency position of the NR SL-SSB to the NR V2X terminal has been described. That is, the above-described embodiment may be in the form of providing configuration information for transmitting the NR sidelink synchronization information to the terminals in the form of system information from the NR base station.

In this case, as an example, the case where the terminal is located within the NG-eNB base station coverage may be considered. In this case, the terminal may receive the setting for transmitting the NR side synchronization information included in the system information transmitted on the NG-eNB DL carrier to confirm the information for NR SL-SSB transmission.

That is, the NR sidelink terminal may receive synchronization configuration information for NR sidelink V2X communication within the LTE coverage through the LTE DL. Therefore, the NR sidelink terminal needs to be able to receive system information on the LTE DL. In this case, the NR sidelink terminal may perform NR sidelink communication on the NR UL carrier through system information received through the LTE DL.

At this time, for example, in the above-described embodiments 6-1-1-1 to 6-1-1-5, the embodiment 6-1-1-4 is the initial UL activation BWP in consideration of using the ultra-wideband in NR Information on the start position of the bar may not be included in the system information received through the LTE DL. However, other embodiments except for the above-described embodiment 6-1-1-4 may be provided to the NR sidelink terminal through system information on the LTE DL. That is, since the embodiment 6-1-1-4 may be considered in the NR DL carrier, it may be difficult to apply in the LTE DL system information, and may be applicable in other signaling methods.

실시예 7(시간 도메인 관점)Example 7 (Time Domain Perspective)

Based on Embodiment 6 described above, the NR SL SSB frequency position may be indicated. In this case, it is also necessary to indicate the time transmission resource location for the NR SL SSB. As an example, a case in which the NR sidelink terminal performs NR sidelink V2X communication within 3GPP network coverage (i.e. LTE and NR base station) may be considered. At this time, the NR SL SSB transmission position needs to be determined in the time domain, and DL / FL / UL resource configuration on the LTE / NR Uu link needs to be considered.

In the following, a method for NR SL SSB transmission time resources is described independently of a method for configuring a resource pool for NR sidelink V2X communication. That is, although it may be associated with the frequency position of the NR SL SSB as in the sixth embodiment, the time resource may be independently indicated, and is not limited to the above-described embodiment.

In this case, as an example, the NR sidelink V2X communication may be operated in a high frequency frequency band region and may be performed based on a plurality of beams to correspond to signal attenuation. Therefore, NR SL SSB transmission also needs to consider this. However, for example, it may be possible to operate based on a single beam according to the terminal implementation or the characteristics of the band to be operated, and is not limited to the above-described embodiment.

However, in consideration of the above-described environment, unlike the LTE sidelink, the NR sidelink for NR V2X needs to transmit a synchronization signal (PSSS / SSSS) and a broadcast channel (eg PSBCH) in one block form. There is a need to have a structure to transmit periodically in the time domain.

Also, as an example, DL / FL / UL slots and symbols may be variably set in both NR FDD / UL and TDD. However, in consideration of the system operation of the NR system, DL SSB transmission / reception operation needs to be guaranteed. That is, it is necessary to ensure the operation for DL SSB transmission and reception in consideration of the information that is necessarily provided as system information. For this purpose, the time and frequency domain in which the DL SSB is transmitted need to be always set to DL. In addition, the terminal may also perform a DL SSB reception operation based on the above-described configuration. That is, the NR base station may set the DL SSB indexes for transmitting the DL SSB to always operate as DL symbols. For example, regardless of FDD / TDD / SUL, a slot format indicator by DCI format 2_0 with SFI-RNTI (SFI) indicator may periodically adjust the ratio of DL / FL / UL symbols for each slot. In this case, as an example, the DL SSB transmitted by the NR base station in a cell may indicate related signaling to the DL so that the DL is always DL.

In addition, as an example, a TDD UL-DL configuration may also allow a symbol on which a corresponding DL SSB is transmitted to always be a DL slot / symbols. The terminal may also assume that the symbol on which the DL SSB is always transmitted is DL based on the above description and perform a reception operation.

In this case, in consideration of the above, it may be necessary to determine at what time the NR SL-SSB is transmitted. That is, since the DL-SSB transmission should be guaranteed, the SL-SSB needs to be transmitted at least avoiding the time when the DL-SSB is transmitted.

For example, in the case of TDD, DL / UL may not exist at the same time, so the SL-SSB may be transmitted by avoiding the time when the DL-SSB is transmitted. Further, for example, even in the case of FDD, when the UE has only one transmit / receive RF chain, multiplexing on a signal transmitted on the DL (eg DL SSB) and a signal transmitted or received on the UL (eg SL-SSB) may be restricted. Can be.

Also, for example, setting the above-described FDD and TDD to have the same SL-SSB time transmission structure may simplify the implementation and is not limited to the above-described embodiment. In consideration of the above, it can be considered that the DL SSB and the SL SSB are determined by the time division multiplexing (TDM) method for determining the location of time resources. Hereinafter, a more specific SL-SSB burst set will be described.

More specifically, the position of the SL SSB burst in the time domain can be indicated. For example, NR-SL SSB transmission may configure one NR-SL SSB burst set from a time domain perspective. In this case, like the NR system, the NR sidelink may consider beam-based transmission to provide signal attenuation, coverage maintenance, and transmission efficiency on a high frequency band. Thus, one NR-SL SSB burst set may consist of one or more NR-SL SSBs.

At this time, as an example, the period of the NR-SL SSB burst set (

) Can be set. At this time,

Can be used as a fixed value. Also, as an example, the PSL-SSB may be set to any one of [5, 10, 20, 40, 80, 160, 320, 640 ms]. Also, as an example,

May be set in advance and is not limited to the above-described embodiment.

In addition, the time window interval of the NR-SL SSB burst set (

) Can be set. At this time,

As the length, any one of a plurality of values may be selected and used. Also, as an example, the starting point of the NR-SL SSB burst set (

) May be set and signaling indicating SSL-SSB may be required. That is, the period information in the NR-SL SSB burst set

Time window information

And SSL-SSB which is information about the starting point.

In this case, as an example, Table 34 shows a time window length of an NR-SL SSB burst set.

It may be a method of setting. In addition, Table 35 shows information about the starting point of the NR-SL SSB burst set.

It may be information about.

More specifically, the time window length of the NR-SL SSB burst set may be indicated based on a 5 ms unit that is a half frame unit, which is the same as option 1 of Table 34 below. In this case, as an example, up to K units may be set up to 5 ms, and an indication based on this may be performed.

Also, as an example, the time window length of the NR-SL SSB burst set may be indicated in units of slots, which is the same as option 2 of Table 34 below. In this case, as an example, up to 320 slots may be set, and an indication based on this may be performed.

In addition, the time window length of the NR-SL SSB burst set may be indicated based on the set number of SSBs, which is the same as option 3 in Table 34 below. In this case, as an example, the number of SSBs may be set up to L, and an indication based on this may be performed.

In addition, the time window length of the NR-SL SSB burst set may be indicated by “msec” as a time unit, which is the same as option 4.

Table 34

Also, as an example, the starting point of the NR-SL SSB burst set may be indicated based on Table 35 below. At this time, the start point of the NR-SL SSB burst set may be indicated based on the “NR SL-OffsetIndicatorSyn” parameter, and specific indication methods may be as shown in Table 35 below.

In more detail, the starting point of the NR-SL SSB burst set may be indicated in units of 5 ms. At this time, since each half frame is 5ms in one frame, a starting point may be indicated through a value of 0 or 1, which is the same as option 1 of Table 12.

In addition, a start point of the NR-SL SSB burst set may be indicated in units of slots, and may indicate a start point by indicating a slot position, which is the same as option 2 of Table 35.

In addition, the starting point of the NR-SL SSB burst set may be indicated by the SSB index. In this case, a starting point may be indicated through the SSB index value, which is the same as option 3 of Table 35.

In addition, a start point of the NR-SL SSB burst set may be indicated as a unit of msec number. For example, as the above-described "TDD UL-DL transmission periodicity", the location of the starting point may be indicated based on P msec, which is the same as option 4 of Table 35.

Table 35

That is, as described above, time domain resource information for the NR-SL SSB burst set may be indicated. In this case, as an example, the UE needs to determine the SL SSBs that are actually available within the indicated time domain resources. More specifically, even if time domain resource information for the NR-SL SSB burst set is indicated, there may be a case where the UE is unavailable.

For example, in case of FDD / SUL, all of the SL SSBs may be located on the UL within the indicated SL-SSB burst window. Accordingly, the UE may determine that all SL SSBs are available SSBs in the SL-SSB burst window.

On the other hand, in another example, in the case of TDD, one band with part / carrier (BWP / Carrier) may be separately set based on time as DL / FL / UL. In this case, in order for the terminal to transmit the SL SSBs in the SL-SSB burst window, a resource corresponding to “UL slot” or “UL slot + symbol” may be needed. Accordingly, the SL SSBs located in the “UL slot” or the “UL slot + symbol” among the SL SSBs may be determined as available SL SSBs.

In addition, as an example, it may be considered that the SL SSB may exist only in a UL slot configured only with a UL symbol. In this case, only the UL slot in the SL SSB burst window may be considered as a candidate for the SL SSB transmission, and signaling based on this may be performed. This will be described later.

As another example, a V2X terminal configured with SFI may be considered. In this case, as an example, the SFI may not be configured for the NR V2X terminal in consideration of V2X implementation and operation. As another example, the SFI may be configured in the V2X terminal in consideration of the association with the NR Uu link. For example, when the SFI is configured in the terminal, the terminal may recognize that the SL SSBs exist only in the UL slot ”or the“ UL slot + symbol ”.

Hereinafter, specific embodiments based on time domain resource information for the SL-SSB burst window indicated as described above and available SL SSB determination methods of the UE will be described.

실시예 7-1(5ms 단위 시작 오프셋과 5ms 단위 SL SSB 버스트 윈도우 구간)Example 7-1 (Starting Offset in 5ms and SL SSB Burst Window Interval in 5ms)

16 and 17 illustrate a method of configuring and indicating an NR SL SSB burst set. More specifically, as an example, the offset with respect to the start point of the SL SSB burst set may be indicated in units of 5 ms. Also, as an example, the SL SSB burst window period may also be set in 5 ms units.

At this time, the transmission position of the SL SSB burst set may be indicated by Equation 3. In this case, based on Equation 3, the start point of the SL SSB burst set (NR SL-OffsetIndicatorSync) may be indicated by a direct frame number (DFN) and a half frame as a mod function for the period of the SL SSB burst set. In this case, the half frame may be indicated by 0 or 1 as described above in 5 ms units.

[Equation 3]

More specifically, in Equation 3, DFN may be a frame index for time domain reference of the NR sidelink. In addition, Hf is a half frame index and a value of 0 may correspond to the first 5ms of the DFN. Also, a value of 1 (or 5) may correspond to 5 ms after the DFN. Also, as an example, NR-SL SSB burst set periodicity (

) Can be used as a fixed value. Also,

May be set to any one of {5, 10, 20, 40, 80, 160, 320, 640 msec} or a preset value, as described above.

In this case, as the above-mentioned parameter, "NR SL-OffsetIndicatorSync" may indicate the actual NR-SL SSB burst set transmission interval to the terminal through system information or an RRC resetting message transmitted from the NG-RAN base station. That is, the terminal obtains information on the "NR SL-OffsetIndicatorSync", and can confirm the starting point based on Equation 3 described above. In addition, the indicated time interval may be used for NR SL-SSB transmission.

Also, as an example,

May indicate one period to which the TDD UL-DL configuration is applied. At this time,

May be set to any one of {0.5, 0.625, 1, 1.25, 2, 2.5, 5, 10}. At this time, the TDD operation is set as described above.

Can be performed based on a value. The TDD Inva UE may identify the location of the time domain by checking the UL resource. In this case, as an example, the TDD UL-DL configuration indicator may have a ratio of DL, FL, and UL slot / symbol.

It can indicate how it is configured within the period, and can operate based on it.

In this case, as an example, FIG. 16 may correspond to an NR SL SSB burst set configuration and indication method in FDD / SUL. In addition, FIG. 17 may be an NR SL SSB burst set configuration and indication method in TDD.

For example, referring to FIG. 16, information on a start time of an SL-SSB burst time window may be indicated through a “NR SL-OffsetIndicatorSync” parameter based on a 5 ms time unit, as described above. That is, the SL-SSB burst start position in one SL SSB burst set period may be indicated through the above-described parameters in units of 5ms. As a specific example, in Equation 3

If the value is 320ms, 64 offset values (NR SL-OffsetIndicatorSync) possible in the unit of 5ms may exist. At this time, each offset value is {0, 5, 10, 15, 20,... 315 msec}. However, the above description is just one example, and the PSL-SSB and offset time unit values may be changed and set.

In addition, as an example, the SL-SSB burst window time interval (SL-SSB burst window) may be set based on a predetermined value (e.g. 5msec) or a set value (e.g. configuration or preconfiguration information from the LTE / NR cell). At this time, the terminal may select and transmit the SL-SSBs based on the respective SL-SSB time positions defined in the window time interval. In this case, the predetermined SL-SSB time position in FIG. 16 may correspond to “SL-SSB candidates”. In this case, as an example, “SL-SSB candidates” may exist at a predetermined position within a predetermined time window using at least two parameters (offset, window).

Also, as an example, FIG. 17 is a diagram illustrating a TDD case. In this case, unlike FDD / SUL, TDD may be divided into DL, FL (Flexible symbols), and UL in the time domain. In this case, the above-described Ptdd parameter may be used to identify an UL time resource region in which “SL-SSB candidates” may be located based on TDD UL-DL configuration information. That is, the UL resource region may be identified within the SL-SSB burst window. However, as an example, a flexible symbol may also be considered for SL-SSB transmission according to additional configuration, signaling, or preconfiguration of the base station. That is, the SL-SSB transmission may be performed based on the additional setting, which is not limited to the above-described embodiment.

실시예 7-2(슬롯(또는 슬롯+OFDM 심볼) 단위 시작 오프셋과 슬롯(또는 슬롯+OFDM 심볼) 단위 SL SSB 버스트 윈도우 구간)Example 7-2 (Starting Offset in Slot (or Slot + OFDM Symbol) and SL SSB Burst Window Interval in Slot (or Slot + OFDM Symbol))

18 and 19 illustrate a method of setting a start offset and an SL SSB burst window interval based on a slot (or slot + OFDM symbol) unit.

For example, when the start offset is indicated based on the slot unit, it may be configured as shown in Equation 4 below.

[Equation 4]

In this case, similar to Equation 3, the direct frame number (DFN) may be a frame index for the time domain reference of the NR SL. In addition, the slot number may be a value between 0 and 320 as an index of a slot that may exist in the DFN. Also,

May mean the number of slots present in a subframe corresponding to a 1 ms time. In addition, as an example, “NR-SL SSB burst set periodicity (PSL-SSB) may be fixedly used as one value. In addition, as an example, the PSL-SSB may be set to any one of {5, 10, 20, 40, 80, 160, 320, 640 msec} or may be set in advance, as described above.

In addition, the “NR SL-OffsetIndicatorSync” may indicate the actual NR-SL SSB burst set start point to the terminal through system information or an RRC reset message transmitted from the NG-RAN base station. In this case, the UE may use the indicated time interval for NR SL-SSB transmission and may be similar to the embodiment 7-1.

However, the base station may set or preconfigure the offset value of the “NR SL-OffsetIndicatorSync” and the SL-SSB burst window in units of slots. That is, it can be set in slot units instead of in 5 ms units.

In this case, as an example, an offset value may additionally indicate a slot index + an OFDM symbol index. For example, the above-described offset value may be effective for the V2X terminal in which the SFI is set as shown in FIG. 19 and the V2X terminal operating in the TDD network as shown in FIG. 18.

More specifically, the TDD setting or the SFI setting may be indication information for providing a combination of DL / FL / UL in a slot. In this case, the UL OFDM symbols cannot be accurately indicated in the slot / msec unit. In addition, for example, in order to satisfy the requirements of the V2X service, which is one of the URLLC services, it is necessary to consider the symbol level data transmission / reception operation in the NR V2X. Therefore, in the above description, in order to perform a more accurate indication, it may be indicated by a combination of "slot" or "slot + OFDM symbol", and is not limited to the above-described embodiment. In addition, as an example, the SL-SSB burst window size may be indicated by a combination of “slot” or “slot + OFDM symbol”, and is not limited to the above-described embodiment.

실시예 7-3(SL-SSB 단위 시작 오프셋과 SL-SSB 단위 SL SSB 버스트 윈도우 구간)Example 7-3 (SL-SSB Unit Start Offset and SL-SSB Unit SL SSB Burst Window Interval)

As another example, the SL-SSB unit start offset and the SL-SSB unit SL SSB burst window interval may be indicated to the UE through the SL-SSB index and the number thereof. More specifically, each SL-SSB may have an index, and similarly to the embodiments 7-1 and 7-2, the SL-SSB burst may be divided by using the frame index as the DFN and the index to the SL-SSB. You can indicate the starting point. In addition, the size of the SSB burst window may be indicated using the SL-SSB index used, and the present invention is not limited thereto.

실시예 8(3GPP 네트워크 또는 기설정(pre-configuration)에서 제공되는 추가적인 SL-SSB 자원 지시 방법)Embodiment 8 (additional SL-SSB resource indication method provided in 3GPP network or pre-configuration)

Based on the sixth and seventh embodiments described above, the frequency position and the time position for the SL-SSB burst set may be indicated.

In this case, as an example, the SL-SSB resource may be additionally indicated based on information provided in the 3GPP network or the preset.

In more detail, in the above-described manner, V2X terminals may perform channel transmission for transmitting synchronization and MIB information on corresponding resources through the SL-SSB resource indication method in the SL-SSB burst window. However, all NR SL-SSBs in the corresponding NR-SL SSB burst set time interval may not be used for actual transmission. For example, the NR base station may not allow the transmission of the SL-SSBs. More specifically, in the NR system, only the NR base station could transmit the DL SSB. However, one or more terminals capable of transmitting SL-SSB may be present in one cell in consideration of the NR sidelink. That is, unlike conventional NR systems, since NR sidelinks have multiple terminals capable of transmitting SL-SSB in one cell, the NR sidelink is based on at least one of RF capability, antenna configuration and number, and beamforming transmission method of each terminal. The number of SL-SSBs to be actually used can be set differently for each UE. Thus, additional signaling as to whether the transmission of SL-SSBs is allowed by the NR base station may be necessary.

In this case, only the NR base station may transmit the DL SSB, but the NR base station may also schedule resources for UL data transmission to terminals in the cell for transmitting and receiving data on the NR Uu link. To this end, the NR base station may need to configure a UL channel (e.g. configured PUSCH) and signals (e.g. SRS). Therefore, the use of uplink transmission resources of the NR Uu link may be limited for SL-SSB transmission. Accordingly, the LTE / NR base station, which is a 3GPP network, needs to additionally signal the NR sidelink terminals to the SL-SSB transmission index available within the NR-SL SSB burst set time. Through this, it is possible to increase the efficiency of NR UL carrier resource utilization.

Hereinafter, as a more specific case, an additional SL-SSB resource indication method of the base station in the case of TDD and FDD / SUL will be described.

At this time, in the following embodiment, the terminal checks the configuration information on the start and size of the SL-SSB burst window on the basis of the above-described

embodiments

6 and 7, and in addition to the actual "configured SL SSB candidate" information in the actual network Consider the case of receiving information on the available SL-SSB. In this case, the terminal may perform the final SL-SSB transmission in the “SL SSB candidate” determined by the terminal itself from among the indicated “configured SL SSB candidates”.

In addition, as an example, when additional signaling is not provided to the UE, the UE may use the “SL SSB candidate” available based only on configuration information about the start of the SL-SSB burst window and the size of the SL-SSB bursts performed in

Embodiments

6 and 7. And the present invention is not limited to the above-described embodiment.

In this case, as an example, FIG. 20 may be an operation for additional signaling based on the above description in consideration of the case of TDD. In addition, FIG. 21 may be an operation for additional signaling based on the above in consideration of the case of FDD / SUL having SFI.

For example, in FIG. 20 and FIG. 21, the value “L” may be the number of SL-SSBs in the NR SL-SSB burst set. In this case, as an example, the L value may be determined differently according to the range of the frequency band in which the NR sidelink is operated, which may be as shown in Table 36 below. For example, the L value may increase as the frequency increases. That is, the number of SL-SSBs may increase in the case of using a broadband as a high frequency.

TABLE 36

In addition, as an example, in FIG. 20 and FIG. 21, the value “N” may be the number and the resource indexes allowed in the network for L-valued NR-SL SSB transmission. At this time, the base station may indicate the information on the N value to the NR sidelink terminals. As an example, the indication method may be a bitmap or an index value, but is not limited to the above-described embodiment.

In this case, as an example, when the terminal does not receive the above-described information on the "N" value, the terminal may determine the SL-SSB actually used based on a predetermined value. Also, as an example, the UE may determine the SL-SSB actually used based on the NR SL SSB index based on the L value described above.

In addition, as an example, in FIG. 20 and FIG. 21, the value “K” may be the number of NR-SL indexes actually used by the corresponding terminal.

In more detail, referring to FIGS. 20 and 21, the terminal may receive an indication of a frequency position and a time position for the SL SSB burst set based on the above-described

embodiments

6 and 7, and based on this, SL SSB Candidates may be determined. Thereafter, as described above, information about the resource index and the number of resources (“N” value) allowed in the network may be further signaled. In this case, the NR sidelink terminals receiving the above-described information may determine the actual transmission in consideration of beam transmission characteristics, antenna / RF setting, and transmission method for each terminal among one or more indicated NR-SL SSB indexes. You can determine the SSB index, number (“K” value), and beam shape. Thereafter, each terminal may perform respective NR-SL SSB transmission. In this case, as an example, SL-SSB transmission may be performed based on different SL-SSB indexes with potentially different “K” values for each terminal, and is not limited to the above-described embodiment.

More specifically, the NR sidelink terminal can determine the number of NR-SL SSBs (“N” values) indicated in the actual network among the L SSBs that can be transmitted according to the frequency band and a set of symbols in the slot corresponding to the index. have. Thereafter, the terminal may be configured and not used as a downlink on a symbol in a slot corresponding to the indicated NR SL-SSB indexes. The network (base station) can ensure that the symbols are always UL. That is, both the network and the NR sidelink terminal can guarantee each other that the symbols in the corresponding slots are always UL. Therefore, from the viewpoint of the NR sidelink terminal, transmission can be performed by selecting a desired NR SL-SSB at all times.

In addition, as an example, based on the above, NR SL-SSB transmission symbols may be stably transmitted and received without colliding with DL transmission (e.g. PDSCH, CSI-RS, etc.) on the NR Uu link. In this case, as an example, the network view may indicate that the slot format indicator (DL / FL / UL symbol structure indicator in the slot indicated through the common PDCCH scrambled with SFI-RNTI) corresponds to UL symbols based on the above description. Can be. Also, for example, in the case of TDD, at least one of “TDD UL-DL configurationCommon”, “TDD UL-DL configurationCommon2”, and “TDD UL-DL configurationDedicated” is provided to NR Uu terminals to indicate that they correspond to UL symbols. can do.

In addition, although the above has described TDD and FDD / SUL with SFI, in the absence of SFI, the above-described signaling may be applied on the assumption that all slots consist of only UL symbols. In addition, as an example, even in the case of TDD, the SFI value may be applied and is not limited to the above-described embodiment.

As another example, FIG. 22 illustrates a case where an SL-SSB available in an "UL slot" or an "UL slot + symbol" may be located. As an example, in FIG. 20 and FIG. 21 described above, a signaling method is described based on a case where a SL-SSB is potentially present in a fixed position irrespective of a DL / FL / UL slot or a symbol. However, as shown in FIG. 22, whether the SL-SSB available only in the UL slot ”or the“ UL slot + symbol ”may be located may have the size of the above-described“ N ”value and“ K ”value. In this case, as an example, the operation of determining, by the terminal, the SL-SSB frequency position and the time position based on the sixth and seventh embodiments and receiving additional signaling may be equally applied to FIG. 22. It is not limited to.

In addition, FIG. 23 illustrates a floating side link SSB burst structure as an example.

Referring to FIG. 23, the SL SSB burst transmission may not be performed based on a 5 ms boundary. In this case, as an example, a specific slot in a specific DFN may be used as a starting point by using a range of offset values corresponding to the number of slots in the DFN. At this time, the transmission may be performed using the SLSS / PSBCH block of the “K” value determined by the transmitting NR V2X UE from among the aforementioned “L” value of the number of SL-SSBs or “N” value allowed by the network. The method is as described above.

On the other hand, the start point of the floating SL SSB burst may be indicated by the base station by providing the terminal with a "DFN + slot" index value compared to DFN 0 through the "NR SL-offsetIndicatorSync" parameter. In this case, additionally, the size (or length) information of the SL SSB burst may be provided to the terminal through the “NR SL-lengthIndicatorSync” parameter. As an example, the size may be indicated in units of slots, subframes, or “ms”. In this case, candidate positions of possible SL-SSBs may be defined as “L” values in the indicated window, as described above.

For example, similarly to the 5ms window case described above, the 3GPP network selects the SL-SSB of the “N” value set in the network in consideration of the settings for SL-SSB transmission on the LTE or NR Uu link among the “L” values. System information can be set for each cell. Thereafter, the terminal may determine and transmit the actual number of SL-SSBs to be transmitted as a “K” value in consideration of the antenna configuration of the terminal, the RF capability, the method of forming the beam, and the coverage.

실시예 9(DL SSB 버스트 윈도우와 SL SSB 버스트 윈도우가 오버랩되는 경우)Example 9 (when DL SSB burst window overlaps with SL SSB burst window)

In addition, FIG. 24 is a diagram illustrating a case where the DL SSB burst window and the SL SSB burst window overlap. At this time, as an example, when the SL SSB burst transmission is indicated by the above-described "NR SL-OffsetIndicatorSync" value on 5 ms equal to the DL SSB burst set, the SL SSB burst is a TDM as shown in FIGS. 24A to 24C. It may be instructed to the terminal in the form. For example, the DL SSB burst and the SL SSB burst actually transmitted by the NR base station may be as shown in FIG. 24 (a). Alternatively, the DL SSB burst and the SL SSB burst actually transmitted by the NR base station may be as shown in FIG. 24 (b). The DL SSB burst and the SL SSB burst actually transmitted by the NR base station may be as shown in FIG. 24 (c). In this case, as described above, the importance of the DL SSB burst may be high, and therefore, it is always transmitted first, and the SL SSB burst may be allocated thereafter. In addition, as an example, the UE may always perform UL transmission at a time resource location corresponding to the SL-SSB transmission index indicated by the network. Accordingly, the UE may not set DL and / or FL symbols in the SL-SSB transmission symbols corresponding to the SFI index value indicated by the DCI format 2_0, but is not limited to the above-described embodiment. .

25 is a diagram illustrating a method for establishing a SL-SSB resource.

Referring to FIG. 25, the terminal may receive resource configuration information for SL-SSB transmission from the base station (S2510). At this time, as described above with reference to FIGS. 1 to 24, the terminal may transmit resources for SL-SSB transmission. The configuration information can be received from the base station. In this case, the resource for the SL-SSB transmission may be provided to the terminal as frequency position information from the perspective of the frequency domain. That is, as in the sixth embodiment, the terminal may be instructed by the base station to obtain the frequency location information on the SL-SSB. In addition, as an example, resources for SL-SSB transmission may be provided to the terminal as time location information from a time domain perspective. That is, as in the above-described seventh embodiment, the terminal may receive time location information on the SL-SSB from the base station. In addition, as an example, the terminal may receive additional information as well as the above-described information from the base station. That is, as in the above-described eighth embodiment, the terminal may receive additional information regarding the SL-SSB.

In this case, as an example, the information about the sixth to eighth embodiments may be information received in association with each other. As another example, the information on each of the above-described sixth to eighth embodiments may be information independently received from each other, and is not limited to the above-described embodiment.

26 is a diagram illustrating the configuration of a base station apparatus and a terminal apparatus according to the present disclosure.

The base station apparatus 2600 may include a processor 2610, an antenna unit 2620, a transceiver 2630, and a memory 2640.

The processor 2610 performs baseband related signal processing and may include an upper layer processor 2611 and a physical layer processor 2612. The upper layer processor 2611 may process operations of a medium access control (MAC) layer, a radio resource control (RRC) layer, or more upper layers. The physical layer processor 2612 may process operations (eg, uplink reception signal processing and downlink transmission signal processing) of a physical (PHY) layer. In addition to performing baseband related signal processing, the processor 2610 may control the overall operation of the base station apparatus 2600.

The antenna unit 2620 may include one or more physical antennas, and may include multiple input multiple output (MIMO) transmission and reception when a plurality of antennas are included. The transceiver 2630 may include a radio frequency (RF) transmitter and an RF receiver. The memory 2640 may store computationally processed information of the processor 2610, software, an operating system, an application, and the like related to the operation of the base station apparatus 2600, and may include components such as a buffer.

Processor 2610 of base station 2600 may be configured to implement the operation of the base station in the embodiments described herein.

The terminal device 2650 may include a processor 2660, an antenna unit 2670, a transceiver 2680, and a memory 26260.

The processor 2660 performs baseband related signal processing and may include an upper layer processor 2661 and a physical layer processor 2662. The upper layer processor 2661 may process operations of the MAC layer, the RRC layer, or more upper layers. The physical layer processor 2662 may process an operation of the PHY layer (for example, downlink reception signal processing and uplink transmission signal processing). In addition to performing baseband related signal processing, the processor 2660 may control the overall operation of the terminal device 2650.

The antenna unit 2670 may include one or more physical antennas, and may support MIMO transmission / reception if the antenna unit 2670 includes a plurality of antennas. The transceiver 2680 may include an RF transmitter and an RF receiver. The memory 2690 may store arithmetic processed information of the processor 2660, software related to the operation of the terminal device 2650, an operating system, an application, and the like, and may include components such as a buffer.

The processor 2660 of the terminal device 2650 may be configured to implement the operation of the terminal in the embodiments described in the present invention.

In the operations of the base station apparatus 2600 and the terminal apparatus 2650, the details described in the examples of the present disclosure may be applied in the same manner, and redundant descriptions thereof will be omitted.

Exemplary methods of the present disclosure are represented as a series of operations for clarity of description, but are not intended to limit the order in which the steps are performed, and each step may be performed simultaneously or in a different order as necessary. In order to implement the method according to the present disclosure, the illustrated step may further include other steps, may include remaining steps except for some steps, or may include additional other steps except for some steps.

The various embodiments of the present disclosure are not an exhaustive list of all possible combinations and are intended to illustrate representative aspects of the present disclosure, and the matters described in the various embodiments may be applied independently or in combination of two or more.

In addition, various embodiments of the present disclosure may be implemented by hardware, firmware, software, a combination thereof, or the like. For hardware implementations, one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), General Purpose It may be implemented by a general processor, a controller, a microcontroller, a microprocessor, and the like.

The scope of the present disclosure is intended to cover any software or machine-executable instructions (eg, operating system, applications, firmware, programs, etc.) and operations that cause an operation in accordance with various embodiments of the methods to be executed on a device or computer. Instructions, and the like, including non-transitory computer-readable media that are stored and executable on a device or computer.

The present invention can be applied in various systems.

Claims

In a method for a terminal to perform a synchronization procedure in a NR (New Radio) V2X (Vehicle to everything) system,

Determining whether a frequency for V2X sidelink communication of the terminal is within coverage on a network; And

Selecting a synchronization reference source based on whether the frequency is within coverage on the network.
In a resource setting method of a terminal in a NR (New Radio) V2X (Vehicle to everything) system,

Receiving, by the terminal, resource configuration information for transmitting a Sidelink-Synchronization Signal Block (SL-SSB) from a base station; And

And transmitting the SL-SSB based on the received resource configuration information.

The resource configuration information for the SL-SSB transmission includes frequency location information for the SL-SBB and time location information for the SL-SSB.