KR20190139624A - Method and apparatus of indicating information related to dmrs for v2x in new radio system - Google Patents

Abstract

Provided in the present invention is a method for a terminal to communicate with another terminal through a side link. Here, the method to communicate may comprise the steps of: acquiring anti-static DMRS-related information; acquiring dynamic DMRS-related information; transmitting an SCI including the dynamic DMRS-related information to another terminal based on the acquired dynamic DMRS-related information; and transmitting the DMRS and data to another terminal through a side link based on the SCI. Here, the dynamic DMRS-related information is determined based on at least one among information on the number of symbols usable among maximum symbols, CDM group information, and DMRS antenna port information. The DMRS antenna port information is determined based on the case in which the terminal only performs a rank 1 transmission. The dynamic DMRS-related information may include the DMRS-related information transmitted by a first terminal and the DMRS-related information transmitted by a second terminal.

Description

METHODS AND APPARATUS OF INDICATING INFORMATION RELATED TO DMRS FOR V2X IN NEW RADIO SYSTEM}

The present invention can provide a method and apparatus for indicating DMRS related information for vehicle to everything (V2X) in a new radio (NR) system.

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

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

The present invention provides a method and apparatus for indicating DMRS related information for V2X in an NR system.

The present invention provides a method and apparatus for indicating DMRS related information in consideration of sidelinks.

The present invention provides a method and apparatus for configuring a table for DMRS related information for V2X.

The present invention may provide a method in which a terminal performs communication with another terminal through a sidelink. In this case, the method of performing communication may include obtaining semi-static DMRS-related information, obtaining dynamic DMRS-related information, and transmitting an SCI including dynamic DMRS-related information to another terminal based on the obtained dynamic DMRS-related information. And transmitting the DMRS and the data to another terminal through the sidelink based on the SCI. In this case, the dynamic DMRS-related information is set based on at least one of at least one of symbol number information, CDM group information, and DMRS antenna port information available in the maximum symbol, and DMRS antenna port information is performed when the UE performs only Rank 1 transmission. Based on the determination, the dynamic DMRS related information may include DMRS related information transmitted by the first terminal and DMRS related information transmitted by the second terminal.

The features briefly summarized above with respect to the present disclosure are merely exemplary aspects of the detailed description of the present disclosure described below, and do not limit the scope of the present disclosure.

According to the present disclosure, when indicating the DMRS-related information for V2X in the NR system, it is possible to reduce the signaling overhead by reducing the amount of information to be delivered.

According to the present disclosure, when performing a V2X operation in an NR system, a method of transmitting DMRS information may be determined in consideration of the DMRS configuration type and the maximum number of symbols.

According to the present disclosure, it is possible to increase the efficiency of the V2X operation by configuring the semi-static information and the dynamic information for the V2X operation in the NR system, respectively.

According to the present disclosure, when performing a V2X operation in the NR system, it is possible to determine a method of delivering DMRS related information based on a base station scheduling mode and a terminal autonomous determination mode.

According to the present disclosure, in a NR (New Radio) V2X (Vehicle to Everything) operating in a base station scheduling mode, the base station is a DMRS (Demodulation Reference Signal) related information to be transmitted to the V2X receiving (RX) terminal by the V2X transmitting (TX) terminal There is an effect that can efficiently indicate to the V2X transmission (TX) terminal.

In addition, the V2X receiving (RX) terminal determined by the base station has an effect that the V2X transmitting (TX) terminal can efficiently instruct the V2X receiving (RX) terminal DMRS-related information to be transmitted to the V2X transmitting (TX) terminal.

According to the present disclosure, in a NR (New Radio) V2X (Vehicle to Everything) operating in the terminal autonomous determination mode, the V2X transmitting (TX) terminal transmits DMRS (Demodulation Reference Signal) related information to be transmitted to the V2X receiving (RX) terminal. There is an effect that the V2X transmitting (TX) terminal can be determined efficiently.

In addition, the V2X receiving (RX) terminal determined by the V2X transmitting (TX) terminal can efficiently instruct the V2X transmitting (TX) terminal to the V2X receiving (RX) terminal for DMRS related information to be transmitted to the V2X transmitting (TX) terminal. It works.

According to the present disclosure, there is an effect of minimizing DMRS interference between terminals in cluster driving, which is one of the main V2X services, in NR V2X, thereby improving performance.

The present invention is not limited to the above-described effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a diagram for explaining a V2X scenario to which the present disclosure may be applied.
2 is a diagram for describing a V2X scenario to which the present disclosure may be applied.
3 is a diagram for explaining a V2X scenario to which the present disclosure may be applied.
4 is a diagram illustrating a V2X related service to which the present disclosure can be applied.
5 is a diagram illustrating a frame structure for downlink / uplink transmission to which the present disclosure can be applied.
6 is a diagram illustrating a resource grid and a resource block to which the present disclosure can be applied.
7 is a diagram illustrating a method of transmitting DMRS related information based on a base station scheduling mode and a terminal autonomous determination mode.
8 is a flowchart of a communication method to which the present disclosure may be applied.
9 is a diagram illustrating a configuration of a base station apparatus and a terminal apparatus to which the present disclosure can be applied.

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. 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, terms such as 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, components that are 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 and formed 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 the system (for example, the base station) that is in charge of the wireless communication network, or the corresponding wireless Work may be done at the terminal coupled to the network.

That is, it is obvious 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 eNodeB (eNB), a gNodeB (gNB), 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 by the term.

For example, the NR system supports various subcarrier spacings (SCS) in consideration of various scenarios, service requirements, and potential system compatibility. In addition, the NR system attempts to overcome unfavorable channel environments such as high path-loss, phase-noise, and frequency offset, which occur on high carrier frequencies. It can support the transmission of the physical signal / channel through the beam of. Through this, NR systems can support applications such as Enhanced Mobile Broadband (eMBB), Massive Machine Type Communications (mMTC) / Ultra Machine Type Communications (uMTC), and Ultra Reliable and Low Latency Communications (URLLC). However, the term NR system herein is used as an example of a wireless communication system, but the term NR system itself is not limited to the above-described features.

Also, as an example, 5G mobile communication technology may be defined. In this case, as an example, the 5G mobile communication technology may be defined including not only the NR system described above but also an existing Long Term Evolution-Advanced (LTE-A) system. That is, 5G mobile communication may be a technology that operates in consideration of backward compatibility with a previous system as well as a newly defined NR system.

For example, the sidelink field of 5G may include both sidelink technology in LTE system and sidelink technology in NR system. In this case, the side link field may be an essential field for improving performance through ultra high reliability and ultra low delay and grafting new and various services.

The following describes the operation and related information for V2X based on the NR system for convenience of description. However, the following features may not be limited to a specific system, and may be similarly applied to other systems that are similarly implemented, and are not limited to the above-described embodiment.

Meanwhile, the V2X may be vehicle based communication. At this time, the concept of a vehicle is changing from a simple vehicle to a new platform. For example, IT technologies are applied to a vehicle, and various V2X services are provided based on this. For example, services such as traffic accident prevention, traffic environment improvement, autonomous driving and remote driving are provided. To this end, with respect to V2X, there is a growing need for development and application of sidelink related technologies.

More specifically, in relation to the existing communication technology, the communication from the base station to the terminal may be downlink, and the communication from the terminal to the base station may be uplink. However, not only communication between the base station and the terminal but also communication between the terminals may be required, and the communication from the terminal to the terminal may be the above-described sidelink. For example, in relation to the aforementioned V2X, communication between vehicles or communication between vehicles and other objects (non-base stations such as a pedestrian UE or a terminal type roadside unit (UE-type RSU)) This may be a sidelink. That is, in the case of performing vehicle-based communication, only the communication with the base station is limited, and thus, the above-described sidelink technology may be developed and applied. Hereinafter, a description will be given of a method for indicating DMRS related information for V2X based on the above description.

1 to 3 are diagrams illustrating a V2X scenario.

At this time, Figure 1 may be a scenario for performing communication based on the above-described sidelink. In addition, FIG. 2 may be a V2X operation scenario using communication with a terminal (or a vehicle) and a base station. In addition, FIG. 3 may be a scenario in which V2X operation is performed using both sidelink and communication with a base station.

At this time, for example, with respect to V2X, the terminal described below may be a vehicle. Hereinafter, the terminal is referred to as a terminal for convenience of description, but the terminal may be a vehicle for V2X. In addition, as an example, the terminal may refer to a device capable of performing communication with the sidelink and the base station, and is not limited to the above-described embodiment. However, hereinafter, referred to as a terminal for convenience of description.

(Sidelink group destination identity)는 사이드링크 그룹을 구별하기 위한 아이디 정보이고,

는 상술한 사이드링크 동기화를 위한 아이디 정보일 수 있다. 그밖에, 표 1의 SA, TB, TTI 및 RB는 기존 LTE와 동일하게 사용되는 용어일 수 있다. 또한, V2V는 차량간 통신, V2P는 차량 및 보행자간 통신, V2I/N은 차량과 인프라스트럭처/네트워크와의 통신을 의미할 수 있다. 이와 관련해서는 후술한다.In addition, as an example, terms necessary for V2X may be defined as shown in Table 1 below. In this case, as an example, device to device (D2D) may mean communication between terminals. In addition, ProSe may refer to a proximity service for a terminal performing D2D communication. In addition, SL (sidelink) may be the above-described sidelink, SCI (Sidelink Control Information) may mean the control information associated with the above-described sidelink. In addition, the physical sidelink shared channel (PSSCH) is a channel through which data is transmitted through the sidelink, and the physical sidelink control channel (PSCCH) may be a channel through which control information is transmitted through the sidelink. In addition, the PSBCH (Physical Sidelink Broadcast Channel) is a channel for transmitting a signal in a broadcast manner through the sidelink can be transmitted system information. In addition, the physical sidelink discovery channel (PSCH) may be a channel used for a signal discovery as a discovery channel. In addition, the sidelink synchronization signal (SLSS) may be a synchronization signal for sidelink, and the physical-layer sidelink synchronization identity (PSSID) may be ID information for sidelink synchronization. In addition,

Sidelink group destination identity is identity information for identifying a sidelink group.

May be ID information for sidelink synchronization described above. In addition, SA, TB, TTI, and RB of Table 1 may be terms used in the same manner as the existing LTE. In addition, V2V may mean communication between vehicles, V2P may mean communication between vehicles and pedestrians, and V2I / N may mean communication between vehicles and infrastructure / networks. This will be described later.

TABLE 1

Also, for example, control information transmitted from a terminal to another terminal in V2X communication may be SA. When the above control information is used in sidelink communication, the above control information may be SCI. In this case, the control information described above may be sidelink, and the control information may be transmitted through PSCCH, which is a channel through which control information is transmitted in the sidelink.

Also, for example, data transmitted from a terminal to another terminal in V2X communication may be configured in TB units. In this case, when data is transmitted through the sidelink, the transmission may be performed through the PSSCH, which is a channel through which the above-described data is transmitted.

In addition, in the present disclosure, an operation mode may be defined according to control information for V2X communication or direct link (e.g. D2D, ProSe, or SL) communication and a resource allocation method for data transmission.

For example, the base station resource scheduling mode (eNodeB resource scheduling mode) is the base station (eNodeB) or the relay node (relay node) scheduling resources used by the terminal for transmitting V2X (or direct link) control information and / or data May be a mode. Through this, the terminal may transmit V2X (or direct link) control information and / or data, and this mode may be the base station resource scheduling mode described above.

For example, the base station or the relay node sidelink (or direct link) the sidelink (or direct link) control information and / or scheduling information on the resource to be used for data transmission through downlink control information (DCI). It can be provided to the transmitting terminal. Accordingly, the sidelink (or direct link) transmitting terminal transmits sidelink (or direct link) control information and data to the sidelink (or direct link) receiving terminal, and the sidelink (or direct link) receiving terminal is sidelink. The sidelink (or direct link) data may be received based on the (or direct link) control information.

In the UE autonomous resource selection mode, a UE selects resources used by the UE to transmit control information and data, and such resource selection is performed by a resource pool (ie, a resource candidate). Set) may be determined by sensing or the like. In this way, the terminal may transmit control information and data, and this mode may be a terminal autonomous resource selection mode.

For example, the sidelink (or direct link) transmitting terminal transmits sidelink (or direct link) control information and data to the sidelink (or direct link) receiving terminal in the resource selected by the user, and the sidelink (or direct link). The receiving terminal may receive sidelink (or direct link) data based on sidelink (or direct link) control information.

In this case, as an example, the base station resource scheduling mode may be referred to as mode 1 in sidelink (or direct link) communication for D2D or the like. In addition, the above-described base station resource scheduling mode may be referred to as mode 3 in sidelink communication for V2X or the like. In addition, the UE autonomous resource selection mode may be referred to as mode 2 in sidelink (or direct link) communication for D2D or the like. In addition, the UE autonomous resource selection mode may be referred to as mode 4 in sidelink communication for V2X or the like. However, this is only one embodiment and is not limited to the above-described name. That is, the same object and the same operation can be viewed in the same mode.

In addition, the following description will be based on V2X communication for convenience of description, but is not limited thereto. For example, the present invention may be equally applied to communication based on a direct link such as D2D, ProSe, and the like, and is not limited to the above-described embodiment.

Also, for example, V2X may be a term used to collectively refer to V2V, V2P, and V2I / N. At this time, each of V2V, V2P, and V2I / N may be defined as shown in Table 1 below, but is not limited thereto. That is, Table 2 below is only one example, but is not limited thereto.

TABLE 2

In addition, the V2X communication may include PC5-based communication, which is an interface for sidelink communication.

For example, Table 3 and FIG. 1 may be scenarios supporting V2X operation based only on the PC5 interface (or SL). In this case, (a) of FIG. 1 may be a V2V operation, (b) may be a V2I operation, and (c) may be a V2P operation. That is, FIG. 1 may be a method of performing communication based on the above-described sidelink, and may perform communication without a base station.

TABLE 3

Meanwhile, Table 4 and FIG. 2 may be scenarios supporting V2X operation based only on a Uu interface (ie, an interface between the UE and the eNodeB). For example, (a) of FIG. 2 may indicate a V2V operation, (b) a V2I operation, and (c) a V2P operation. That is, V2X operation may be supported by using communication between the terminal and the base station.

TABLE 4

Tables 5 and 3 may be scenarios that support V2X operation using both the Uu interface and the PC5 interface (or SL). In this case, FIG. 3A illustrates scenario 3A of Table 5, and FIG. 3B illustrates scenario 3B of Table 5. FIG.

In more detail, based on FIG. 3A, the terminal may transmit a V2X message to other terminals via sidelinks. Any one of the UEs receiving this may transmit a V2X message to the base station through the uplink. The base station receives the V2X message, and can transmit the message based on the downlink to other terminals around. In this case, for example, downlink may be performed through a broadcast scheme.

As another example, FIG. 3 (b) shows that the terminal transmits a V2X message to the base station through uplink, and the base station may transmit at least one terminal or a roadside unit (RSU). Thereafter, the terminal or the RSU receiving the terminal may transmit a message to a plurality of neighboring terminals through the sidelink.

That is, both (a) and (b) of FIG. 3 may support V2X operation using both base station and terminal communication and side links, and are not limited to the above-described embodiment.

TABLE 5

As described above, V2X communication may be performed through a base station, or may be performed through direct communication between terminals. In this case, in case of passing through a base station, in LTE-based V2X communication, transmission / reception may be performed through a Uu link, which is a communication interface between an LTE base station and a terminal. In addition, when the side link is used as direct communication between terminals, in LTE-based V2X communication, transmission and reception may be performed through a PC5 link, which is a communication interface between the terminal and the terminal of the LTE.

In addition, as an example, in the NR system, V2X communication may be performed using communication between the terminal and the base station and side links between the terminal. At this time, as an example, there may be a difference between a communication (uplink / downlink) method between a base station and a terminal in an NR system and a communication (uplink / downlink) method between a base station and a terminal in an existing system. That is, some features may be similar and there may be portions that are changed based on the new system NR system. In addition, as an example, the sidelink may be different from the sidelink in the existing system and the sidelink in the NR system. That is, in consideration of the difference between the communication between the base station and the terminal, the sidelink may also be changed in the NR system, which is a new system. Hereinafter, a method of transmitting DMRS related information for V2X in an NR system will be described based on the above-described feature.

4 is a diagram illustrating a service provided based on a sidelink.

Referring to FIG. 4, V2X related services or Internet of Things (IoT) services may be provided based on 5G sidelinks. In this case, as an example, the 5G sidelink may be a concept including both sidelinks based on the existing LTE system and sidelinks considering the NR system. That is, the service may be provided in consideration of the sidelink applied in each system, and is not limited to the above-described embodiment.

For example, referring to FIG. 4, in relation to a V2X service, a group driving, autonomous driving, advanced sensor, and remote driving service may be provided. In this case, the group driving may be a technique in which a plurality of vehicles dynamically form a group and operate similarly. In addition, autonomous driving may be a technique for driving a vehicle based on fully automated, semi-automated. In addition, the evolved sensor may be a technology for collecting and exchanging data obtained from a sensor or a video image. In addition, the remote driving may be a technology for the technology and applications for remote control of the vehicle. That is, the above-described services can be provided as a service based on V2X. However, the above-described service is only one example and is not limited to the above-described embodiment. In this case, in order to provide the above-described V2X service, requirements such as ultra low delay, ultra connection, low power, and high reliability may be required. Therefore, the 5G sidelink may require an operation method for satisfying the above-described service and its requirements, and a detailed method will be described below in consideration of these requirements.

The following describes the NR system. 5 and 6 are diagrams illustrating a frame structure and a resource block for an NR system.

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

일 수 있다. 이때,

이고,

일 수 있다. 또한,

는 NR 시간 단위와 LTE 시간 단위와의 배수 관계에 대한 상수일 수 있다. 참조 시간 단위로써 LTE에서는

,

및

가 정의될 수 있다.In NR, the base unit of time domain is

Can be. At this time,

ego,

Can be. In addition,

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.

Frame structure

를 가질 수 있다. 이때, 하나의 프레임은

시간에 해당하는 10개의 서브프레임으로 구성된다. 서브프레임마다 연속적인 OFDM 심볼의 수는

일 수 있다. 또한, 각 프레임은 2개의 하프 프레임(half frame)으로 나누어지며, 하프 프레임은 0~4 서브프레임과 5~9 서브프레임으로 구성될 수 있다. 이때, 하프 프레임 1 (half frame 1)은 0~4 서브 프레임으로 구성되고, 하프 프레임 2 (half frame 2)는 5~9 서브 프레임으로 구성될 수 있다.Referring to FIG. 5, 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.

은 듀플렉스 모드 (duplex mode) 차이 등으로 발생하는 TA 오프셋 (TA offset) 값일 수 있다. 기본적으로 FDD (Frequency Division Duplex)에서

은 0을 가지지만 TDD (Time Division Duplex)에서는 DL-UL 스위칭 시간에 대한 마진을 고려해서

고정된 값으로 정의될 수 있다.In Equation 1 below

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

Has zero but TDD (Time Division Duplex) takes into account margin for DL-UL switching time.

Can be defined as a fixed value.

[Equation 1]

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

Referring to FIG. 6, 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.

)를 구성할 수 있다. 자원 블록에 대한 인덱스는 특정 주파수 대역 또는 시스템 대역폭 내에서 활용될 수 있다.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]

Numerologies

Numerology can be configured in various ways to meet the various services and requirements of NR systems. For example, unlike the existing LTE / LTE-A system, one subcarrier spacing (SCS) may be supported, and a plurality of SCSs may be supported.

New numerology for NR systems, including support for multiple SCSs, is designed to address the problem of not being able to use wide bandwidth in the existing frequency range or carrier, such as 700 MHz or 2 GHz. It can operate in carriers or frequency ranges such as 3GHz to 6GHz or 6GHZ to 52.6GHz. However, the scope of the present disclosure is not limited thereto.

For example, referring to Table 6 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. have. 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).

가 2인 경우로서 서브캐리어 스페이싱이 60kHz인 경우에서 일반 CP(Normal CP) 및 확장 CP(Extended CP)가 적용될 수 있으며, 다른 대역에서는 일반 CP만 적용될 수 있다.Further, as an example, in Table 6 below

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

TABLE 6

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 general 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, 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 non-slot may refer to a slot having a number smaller by 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 non-slot having a smaller number of symbols than a normal slot. In this case, the number of OFDM symbols included in the non-slot may be determined in consideration of the frequency range. For example, in a frequency range of 6 GHz or more, a non-slot of 1 OFDM symbol length may be considered. As another example, the number of OFDM symbols defining the non-slot 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 (normal slot length) -1. However, as a non-slot standard, the number of OFDM symbols may be limited to 2, 4, or 7 symbols, but is not limited to the above-described embodiment.

가 1 및 2에 해당하는 서브캐리어 스페이싱이 사용되고, 6GHz 초과의 비면허 대역에서는 에서는 3 및 4에 해당하는 서브캐리어 스페이싱이 사용될 수 있다. For example, in the unlicensed band of 6 GHz or less

Subcarrier spacing corresponding to 1 and 2 may be used, and subcarrier spacing corresponding to 3 and 4 may be used in an unlicensed band above 6 GHz.

슬롯 당 OFDM 심볼의 수

를 나타낸다. 표 7은 표 6에서 제공하는 바와 같이 각 서브캐리어 스페이싱 값에 따른 슬롯 당 OFDM 심볼의 수, 프레임 당 슬롯의 수 및 서브프레임 당 슬롯의 수를 나타낸다. 이때, 표 7에서는 14개의 OFDM 심볼을 갖는 일반 슬롯을 기준으로 상술한 값들을 나타낸다.In addition, Table 7 is for each subcarrier spacing setting in the case of a normal CP

Number of OFDM symbols per slot

Indicates. Table 7 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 6. In this case, Table 7 shows the above values based on a general slot having 14 OFDM symbols.

 TABLE 7

가 2인 경우로서 서브캐리어 스페이싱이 60kHz일 때 확장 CP가 적용될 수 있다. 표 8은 확장 CP인 경우로서 슬랏 당 OFDM 심볼의 수

는 12인 일반 슬롯을 기준으로 각각의 값을 나타낼 수 있다. 이때, 표 8을 참조하면, 60kHz 서브케리어 스페이싱을 따르는 확장 CP인 경우, 슬랏 당 심볼의 수, 프레임 당 슬롯의 수 및 서브프레임당 슬롯의 수를 나타낼 수 있다.In addition, as described above,

Is 2, the extended CP may be applied when the subcarrier spacing is 60 kHz. Table 8 shows the number of OFDM symbols per slot in case of extended CP.

May represent each value based on a general slot of 12. In this case, referring to Table 8, 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 8

In addition, as described above, one subframe may correspond to 1 ms on the time axis. In addition, one slot may correspond to 14 symbols on the time axis. Also, as an example, one slot may correspond to seven symbols on the time axis. Accordingly, each conceivable slot and symbol number may be set differently within 10 ms corresponding to one radio frame. Table 9 may indicate the number of slots and the number of symbols according to each SCS. In this case, as an example, in Table 9, the SCS of 480KHz may not be considered and is not limited to the above-described embodiment.

TABLE 9

DMRS for V2X may be configured based on the above-described NR system. For example, the DMRS may be transmitted on one antenna port corresponding to one layer in the existing V2X.

However, in relation to DMRS transmission for V2X, it may be possible to configure and transmit DMRS while maintaining orthogonality between a plurality of layers.

For example, the number of DMRS Orthogonal Antenna Ports that maintain orthogonality for V2X in the NR system may be 12. More specifically, in the NR system, up to 12 layers may be distinguished in consideration of all terminals in MU (Multi-User) -MIMO. For example, the DMRS antenna port numbers may be set to # 0, # 1, # 2, # 3, # 4, # 5, # 6, # 7, # 8, # 9, # 10, and # 11. As another example, if the number of RS antenna ports corresponding to the first antenna port of DMRS is A, the number of DMRS antenna ports is “#A, # A + 1, # A + 2, # A + 3, # A + 4 , # A + 5, # A + 6, # A + 7, # A + 8, # A + 9, # A + 10, # A + 11 ”.

At this time, the configuration for the DMRS may be configured as a DMRS configuration type 1 (DMRS Configuration Type 1) and DMRS configuration type 2 (DMRS Configuration Type 2). For example, DMRS configuration type 1 may be based on interleaved frequency divisional multiple access (IFDMA), and DMRS configuration type 2 may be based on code division multiplexing (CDM). However, the present invention is not limited to the above-described embodiment, and DMRS configuration type 1 and DMRS configuration type 2 may be distinguished from each other.

In addition, as an example, when transmitting the DMRS, the DMRS may be transmitted using one symbol. As another example, when transmitting the DMRS, two symbols may be used to transmit the DMRS. That is, in the case of transmitting the DMRS, four cases can be considered as shown in Table 10 below based on the above-described DMRS configuration type and symbols used. That is, the case of using one symbol and the case of using two symbols for each DMRS configuration type may be considered.

TABLE 10

가 0이고, 두 개의 심볼인 경우에는

가 0, 1일 수 있다. 또한, p는 지원되는 안테나 포트를 지시할 수 있다.Also, as an example, the supported antenna ports may be as shown in Table 11 below. That is, it may be set as shown in Table 11 below based on the DMRS configuration type and the number of symbols, which will be described later in Tables 13 and 14 below. In this case, for example, may correspond to the number of symbols. That is, in case of one symbol

Is 0 and is two symbols

May be 0 or 1. In addition, p may indicate a supported antenna port.

TABLE 11

In addition, as an example, based on Table 10, the maximum layers that can be used in the case of Single-User (SU) -Multiple Input Multiple Output (MIMO) and Multi-User (MI-)-MIMO are shown in Table 12 below. Can be. That is, the case where the maximum number of DMRS layers available for each UE is N based on SU-MIMO and MU-MIMO may be considered. In this case, each layer may correspond to one of the above-described DMRS antenna ports (12 antenna ports).

TABLE 12

는 안테나 포트일 수 있다. 이때, CDM 그룹(group)은 상술한 DMRS 설정 타입에 따라 다를 수 있으며, 하기 표 13은 상술한 DMRS 설정 타입 1에 대응될 수 있다. 일 예로, DMRS 설정 타입에서 CDM 그룹(group)은 두 개의 그룹으로 구분될 수 있다. 또한, 일 예로, DMRS 안테나 포트는

및

에 의해 결정될 수 있다. 이때, 표 13에서

는 사용 가능한 심볼 수에 의해 설정되는 값일 수 있다. 보다 상세하게는, DMRS 설정 타입 1의 경우로써 사용 가능한 심볼의 수가 두 개인 경우에는 하기 표 13처럼

이

및

인 경우를 고려할 수 있다. 즉, 각각의 심볼에 대응될 수 있다. 따라서, 일 예로, 심볼의 수가 하나인 경우에는

이 고려되지 않을 수 있으며, DMRS 안테나 포트를 구별할 수 있는 변수로 활용할 수 없다. In this case, as an example, the above-mentioned DMRS configuration type 1 and DMRS configuration type 2 may be determined to the maximum distinguishable DMRS antenna port based on Tables 13 and 14 below. For example, in Table 13 below

May be an antenna port. In this case, the CDM group may vary according to the above-described DMRS configuration type, and Table 13 below may correspond to the above-described DMRS configuration type 1. For example, in the DMRS configuration type, a CDM group may be divided into two groups. In addition, as an example, the DMRS antenna port

And

Can be determined by. At this time, in Table 13

May be a value set by the number of available symbols. More specifically, in the case of DMRS configuration type 1, when there are two available symbols, as shown in Table 13 below

this

And

Can be considered. That is, it may correspond to each symbol. Thus, for example, when the number of symbols is one

This may not be considered and cannot be used as a distinguishable variable for DMRS antenna ports.

값은 0부터 3까지만 설정될 수 있는바, 최대 구분 가능한 DMRS 안테나 포트는 4개일 수 있다. 한편, DMRS 설정 타입이 1이고, 사용 가능한 심볼 수가 두 개인 경우에는 하기 표 13에서

값은 0부터 7까지 설정될 수 있는바, 최대 가능한 DMRS 안테나 포트는 8개일 수 있다.That is, when the DMRS configuration type is 1 and the number of available symbols is one,

The value can be set only from 0 to 3, and the maximum distinguishable DMRS antenna ports can be four. On the other hand, when the DMRS configuration type is 1 and the number of available symbols is two,

The value can be set from 0 to 7, so that the maximum possible DMRS antenna ports can be eight.

TABLE 13

는 안테나 포트일 수 있다. 이때, CDM 그룹(group)은 상술한 DMRS 설정 타입에 따라 다를 수 있으며, 하기 표 14는 상술한 DMRS 설정 타입 2에 대응될 수 있다. 일 예로, DMRS 설정 타입에서 CDM 그룹(group)은 세 개의 그룹으로 구분될 수 있다. 또한, 일 예로, DMRS 안테나 포트는

및

에 의해 결정될 수 있다. 이때, 표 14에서

는 사용 가능한 심볼 수에 의해 설정되는 값일 수 있다. 보다 상세하게는, DMRS 설정 타입 2의 경우에 사용 가능한 심볼의 수가 두 개인 경우에는 하기 표 14처럼

이

및

인 경우를 고려할 수 있다. 즉, 각각의 심볼에 대응될 수 있다. 따라서, 일 예로, 심볼의 수가 하나인 경우에는

이 고려되지 않을 수 있으며, DMRS 안테나 포트를 구별할 수 있는 변수로 활용할 수 없다. In addition, as an example, Table 14 may correspond to DMRS configuration type 2. For example, in Table 14 below

May be an antenna port. In this case, the CDM group may vary according to the above-described DMRS configuration type, and Table 14 below may correspond to the above-described DMRS configuration type 2. For example, in the DMRS configuration type, a CDM group may be divided into three groups. In addition, as an example, the DMRS antenna port

And

Can be determined by. At this time, in Table 14

May be a value set by the number of available symbols. In more detail, in the case of DMRS configuration type 2, when there are two symbols available, as shown in Table 14 below

this

And

Can be considered. That is, it may correspond to each symbol. Thus, for example, when the number of symbols is one

This may not be considered and cannot be used as a distinguishable variable for DMRS antenna ports.

값은 0부터 5까지만 설정될 수 있는바, 최대 구분 가능한 DMRS 안테나 포트는 6개일 수 있다. 한편, DMRS 설정 타입이 2이고, 사용 가능한 심볼 수가 두 개인 경우에는 하기 표 14에서

값은 0부터 11까지 설정될 수 있는바, 최대 구분 가능한 DMRS 안테나 포트는 12개일 수 있다.That is, when the DMRS configuration type is 2 and the number of available symbols is one,

The value can be set only from 0 to 5, and the maximum distinguishable DMRS antenna ports can be six. On the other hand, when the DMRS configuration type is 2 and the number of available symbols is two,

The value may be set from 0 to 11, and the maximum distinguishable DMRS antenna ports may be 12.

 TABLE 14

As a more specific example, when using one symbol in DMRS configuration type 1, up to four DMRS antenna ports may be distinguished. For example, DMRS configuration type 1 may be set based on IFDMA. In this case, the intersections "Comb Pattern A" and "Comb Pattern B" may be set for each subcarrier in 12 subcarriers as one PRB (Physical Resource Block) in the frequency domain. In this case, the DMRS pattern may be repeatedly extended to a plurality of PRBs by a bandwidth allocated for transmission of a physical channel (eg, PDSCH, PUSCH, etc.) of each UE on a frequency axis. In addition, the time axis may be applied to each DMRS configuration in one slot. For example, the DMRS configuration may be a "front-loaded DMRS configuration" as a fixed position or an "Additional DMRS configuration" as an additional configuration, and is not limited to the above-described embodiment.

In this case, for example, one PRB includes 12 resource elements (REs). Six REs may be allocated to each symbol for each Comb pattern.

At this time, the DMRS antenna port configuration may be as shown in Table 15 below. For example, in Table 15, the Comb pattern may be “Comb pattern A” or “Comb pattern B”. However, this means different Comb patterns and is not limited to the above-mentioned name. In addition, CS (Cyclic Shift) is a cyclic delay value of a DMRS sequence. When the range of possible values is 0 to X, "CS value A" is 0 and "CS value B" is X / 2. Can be. For example, when X = 12, “CS value A” may have a value of 0 and “CS value B” may have a value of 6. Further, for example, when X = 2π, the value of “CS value A” may be 0 and “CS value B” may be π, but is not limited thereto. That is, when one symbol is used as the DRMS configuration type 1, the symbol may be classified first by a CS value and then by a Comb pattern.

Also, for example, DMRS antenna ports # 0 and # 1 may be allocated to “Comb pattern A” in Table 15 below. In addition, DMRS antenna ports # 2 and # 3 may be allocated to the "Comb pattern B", which is not limited to the above-described embodiment.

TABLE 15

As another example, a case in which the DMRS configuration type is 1 and the number of available symbols is two may be considered. In this case, "Comb Pattern A" and "Comb Pattern B" may be set in two symbols and 12 subcarriers (corresponding to one PRB in the frequency domain), and an intersection is set for each subcarrier as described above. Can be. In this case, the DMRS pattern may be repeatedly extended to a plurality of PRBs by a bandwidth allocated for transmission of a physical channel (eg, PDSCH, PUSCH, etc.) of each UE on a frequency axis. In addition, the time axis may be applied to each DMRS configuration in one slot. For example, the DMRS configuration may be a "front-loaded DMRS configuration" as a fixed position or an "Additional DMRS configuration" as an additional configuration, and is not limited to the above-described embodiment.

In this case, a total of six resource elements (REs) per Comb pattern may be allocated to one symbol in one PRB. The configuration of the DMRS antenna port may be as shown in Table 16 below. In Table 16, a Comb pattern is “Comb pattern A” or “Comb pattern B”, and CS (Cyclic Shift) is a purifying delay value of a DMRS sequence, and “CS value A” when a range of possible values is 0 to X. "May have a value of zero. Also, the value "CS value B" may be X / 2. For example, when X = 12, “CS value A” may have a value of 0 and “CS value B” may have a value of 6. When X = 2π, “CS value A” may have a value of 0 and “CS value B” may have a value of π, but is not limited thereto.

  In addition, the Time Domain-Orthogonal Cover Code (TD-OCC) may be applied to two REs adjacent on the time axis on the same subcarrier in each Comb pattern. At this time, when generating a DMRS sequence, +1 or -1 may be multiplied by a sequence value of a DMRS sequence mapped to a corresponding RE. More specifically, the DMRS sequence value can be multiplied as [+1, +1] or [+1, -1] for the RE that takes precedence on the time axis on the same subcarrier and the next RE on the time axis on the same subcarrier. have.

That is, when two symbols are used as the DRMS configuration type 1, they may be first divided into CS values, secondly, Comb patterns, and finally, TD-OCCs. For example, DMRS antenna ports # 0, # 1, # 4, and # 5 are assigned to "Comb pattern A", and DMRS antenna ports # 2, # 3, # 6, and # 7 are assigned to "Comb pattern B". It may be set, and is not limited to the above-described embodiment.

TABLE 16

As another example, a case in which the DMRS configuration type is 2 and one symbol is used may be considered. In this case, "CDM group A", "CDM group B", and "CDM group C" may be distinguished from one symbol and 12 subcarriers (corresponding to one PRB in the frequency domain). At this time, it means that three CDM groups (group) can be set, it is not limited to the above-mentioned name. In this case, the DMRS pattern may be repeatedly extended to a plurality of PRBs by a bandwidth allocated for transmission of a physical channel (eg, PDSCH, PUSCH, etc.) of each UE on a frequency axis. In addition, the time axis may be applied to each DMRS configuration in one slot. For example, the DMRS configuration may be a "front-loaded DMRS configuration" as a fixed position or an "Additional DMRS configuration" as an additional configuration, and is not limited to the above-described embodiment.

In this case, since each CDM group is three, a total of four REs may be allocated to each CDM group. For example, when using one symbol in the above-described DMRS configuration type 2, the DMRS antenna port may be configured as shown in Table 17 below. At this time, the CDM group (group) may be "CDM group A", "CDM group B" or "CDM group C". Also, as an example, the Frequency Domain-Orthogonal Cover Code (FD-OCC) may be applied to two REs adjacent on the frequency axis on the same symbol in each CDM group. The value is [+1, +1] or [+1, -1]. When a DMRS sequence is generated, +1 or -1 is multiplied by the sequence value of the DMRS sequence mapped to the corresponding RE. That is, the above-described values may be set based on the RE which is given priority on the frequency axis on the same symbol and the next RE which is on the frequency axis on the same symbol. That is, when one symbol is used in the DMRS configuration type 2, it may be first divided into an FD-OCC and then into a CDM group. In this case, as an example, "CDM group A" is set to DMRS antenna ports # 0 and # 1, "CDM group B" is set to DMRS antenna ports # 2 and # 3, and "CDM group C" is set to DMRS antenna Ports # 4 and # 5 may be set and are not limited to the above-described embodiment.

TABLE 17

 Also, as an example, when using two symbols in DMRS configuration type 2, up to 12 DMRS antenna ports may be distinguished. For example, "CDM group A", "CDM group B", and "CDM group C" may be set in two symbols and 12 subcarriers (corresponding to one PRB in the frequency domain). That is, three CDM groups may be set, and are not limited to the above-mentioned names. In this case, the DMRS pattern may be repeatedly extended to a plurality of PRBs by a bandwidth allocated for transmission of a physical channel (eg, PDSCH, PUSCH, etc.) of each UE on a frequency axis. In addition, the time axis may be applied to each DMRS configuration in one slot. For example, the DMRS configuration may be a "front-loaded DMRS configuration" as a fixed position or an "Additional DMRS configuration" as an additional configuration, and is not limited to the above-described embodiment.

 In this case, since each CDM group is three, a total of four REs may be allocated to each CDM group. For example, when using one symbol in the above-described DMRS configuration type 2, the DMRS antenna port may be configured as shown in Table 18 below. In this case, in Table 18, the CDM group may be "CDM group A", "CDM group B", or "CDM group C".

  In addition, the Frequency Domain-Orthogonal Cover Code (FD-OCC) may be applied to two REs adjacent on the frequency axis on the same symbol in each CDM group. The value is [+1, +1] or [+1, -1]. When a DMRS sequence is generated, +1 or -1 is multiplied by the sequence value of the DMRS sequence mapped to the corresponding RE. That is, the sequence value of the above-described DMRS sequence is multiplied with the RE which is given priority on the frequency axis on the same symbol and the next RE on the frequency axis on the same symbol.

  In addition, the TD-OCC (Time Domain-Orthogonal Cover Code) can be applied to two REs adjacent on the time axis on the same subcarrier. The value is [+1, +1] or [+1, -1]. When a DMRS sequence is generated, +1 or -1 is multiplied by the sequence value of the DMRS sequence mapped to the corresponding RE. That is, the sequence value of the above-described DMRS sequence is multiplied with the RE which is given priority on the time axis on the same subcarrier and the next RE on the time axis on the same subcarrier.

That is, when two symbols are used in DMRS configuration type 2, they may be first classified into FD-OCC, then into CDM groups, and finally, into TD-OCC. In this case, as an example, DMRS antenna ports # 0, # 1, # 6, and # 7 are set in "CDM group A", and DMRS antenna ports # 2, # 3, # 8 and # 9 are set in "CDM group B". DMRS antenna ports # 4, # 5, # 10, and # 11 may be set in the "CDM group C", which is not limited to the above-described embodiment.

TABLE 18

7 is a diagram illustrating the above-described base station scheduling mode and terminal autonomous determination mode.

In this case, referring to FIG. 7, a base station scheduling mode may be set as a mode for V2X operation. At this time, the base station scheduling mode may be the above-described mode 3. For example, in mode 3, each of the terminals 720 and 730 may be provided with semi-static configuration information related to DMRS through the RRC from the base station 710. For example, referring to FIG. 7A, the terminal A 720 may receive DMRS-related semi-static information of the terminal A 720 as scheduling information from the base station 710. In addition, the terminal B 730 may also receive the DMRS-related quasi-static information of the terminal B 730 as scheduling information from the base station 710. That is, in mode 3, the base station 710 is involved, and may receive DMRS related information from the base station 710 through the RRC.

In addition, as an example, when the terminals communicate based on the sidelink, the transmitting terminal may receive Downlink Control Information (DCI) from the base station, and transmit SCI (Sidelink Control Information) to the receiving terminal based on the terminal. Thereafter, the transmitting terminal may transmit DMRS and data to the receiving terminal. In this case, the terminal may receive scheduling information from the base station through the DCI. For example, the scheduling information may be DMRS related dynamic configuration information. Thereafter, the transmitting terminal may transmit scheduling information of the terminal to the receiving terminal based on the information received through the DCI. In this case, the scheduling information may be DMRS related dynamic configuration information. Thereafter, the transmitting terminal may transmit data and DMRS to the receiving terminal based on the SCI information.

For example, referring to FIG. 7, the terminal A 720 and the terminal B 730 may receive semi-static configuration information from the RRC from the base station 710, as described above. Thereafter, the base station 710 may transmit DMRS related dynamic configuration information as scheduling information of the terminal A 720 through the DCI.

In this case, as an example, the base station 710 may indicate the above-described DMRS configuration type information through the RRC. The base station 710 may provide the terminal A 720 with information on whether to operate based on one of the DMRS configuration type 1 or the DMRS configuration type 2 through the RRC. In addition, the base station 710 may instruct the terminal A 720 the maximum symbol number information through the RRC. That is, the base station 710 may inform the terminal A 720 whether the maximum number of symbols is one or two based on the above description through the RRC. In this case, as an example, if the maximum number of symbols is one, the terminal A 720 may use one symbol. However, if the maximum number of symbols is two, the terminal A 720 may use one or two symbols. That is, when the maximum number of symbols is two, the terminal A 720 needs to confirm the number of symbols used as additional information. In this case, the above-described information may be included in the DCI as DMRS-related dynamic information. That is, when the maximum number of symbols is two, the symbol number information used by the terminal A 720 may be provided from the base station 710 through the DCI. Through this, the terminal A 720 may recognize a case of distinguishing based on each setting type and the number of symbols in Table 10 described above.

Also, as an example, the DMRS dynamic configuration information may include information about a DMRS antenna port. At this time, the information on which antenna port to use 4, 6, 8, 12 antenna ports based on each case in Table 11 may be included. That is, the DCI may include information on the DMRS antenna port. In addition, as an example, since a plurality of DMRS antenna ports may be used based on MIMO, information on DMRS antenna ports may be included.

Also, as an example, the DMRS dynamic configuration information may include “co-scheduled CDM group” related information. That is, the “co-scheduled CDM group” related information may be included in the DCI, and the “co-scheduled CDM group” will be described later.

Thereafter, the terminal A 720 may provide the related information to the terminal B 730 through SCI based on the DMRS related dynamic information received through the DCI. For example, at least one or more of symbol number information, DMRS antenna port information, and “co-scheduled CDM group” related information to be used may be included in the SCI and provided to the terminal B 730. Thereafter, the terminal A 720 and the terminal B 730 may perform communication through the sidelink, and the transmitting terminal A 720 may transmit DMRS and data to the receiving terminal B 730.

On the other hand, Figure 7 (b) is a terminal autonomous determination mode may be the mode 4 described above. At this time, the terminal A 720 and the terminal B 730 may not have the information signaled from the base station, it is necessary to determine the relevant information directly. In this case, for example, in case of mode 4, UE A 720 may directly determine information (e.g. DMRS configuration type information and maximum symbol number information) corresponding to information provided from the base station. For example, the terminal A 720 may directly determine allocation information for the terminal A 720. In this case, the allocation information for the terminal A 720 may be the semi-static information and dynamic configuration information related to the DMRS of the terminal A 720. In this case, as an example, the semi-static information related to DMRS may be the above-described DMRS configuration type information and / or maximum symbol number information. In addition, as an example, the dynamic configuration information related to DMRS may be one or more of symbol number information to be used, DMRS antenna port information, and “co-scheduled CDM group” information.

 In addition, the terminal A 720 may directly determine the scheduling information for the terminal B 730, and transmits the information about this to the terminal B 730 through the SCI. For example, the terminal A 720 may directly determine the DMRS-related dynamic configuration information, and inform the terminal B 730 through the SCI. In this case, as an example, the DMRS dynamic configuration information directly determined by the terminal A 720 may be symbol number information, DMRS antenna port information, and / or “co-scheduled CDM group” information used as described above. Thereafter, the terminal A 720, which is a transmitting terminal, may directly transmit the determined information to the terminal B 730, which is a receiving terminal, through SCI, and may perform sidelink communication through the transmitted information. That is, the terminal A 720 may transmit DMRS and data to the terminal B 730.

Meanwhile, the above-described "co-scheduled CDM group" may be information indicating a co-scheduled CDM group together for rate-matching. In this case, all cases for the co-scheduled CDM group may not be indicated in order to reduce signaling overhead. For example, the base station may limit only a part of possible cases according to a specific rule through DCI and indicate only this case.

More specifically, the DMRS and the data (NR-PDSCH or NR-PUSCH) may be multiplexed by frequency division multiplexing (FDM) within the same symbol. In this case, a case in which a specific UE transmits DMRS using an RE pattern corresponding to the first CDM group may be considered in consideration of the MU-MIMO environment. However, the above-described information may be terminal specific information, so that the terminal may know only the information using the first CDM group. That is, the UE cannot know whether other UEs transmit DMRS in the RE pattern corresponding to the remaining CDM group except for the above information.

  Therefore, in performing rate-matching for data transmission, it may not be determined whether to exclude or include an RE pattern corresponding to the remaining CDM group. In this case, as an example, it is assumed that the RE pattern is always excluded, so other UEs do not transmit DMRS to the RE pattern corresponding to the remaining CDM group, thus causing a waste of radio resources. Can cause performance degradation. On the other hand, if it is assumed to be included at all times, since other terminals transmit DMRS in the RE pattern corresponding to the rest of the CDM group, the data demodulation performance may be degraded. That is, there is a need to address the above-mentioned problem by indicating a co-scheduled CDM group for rate-matching, and information on this may be included in the DCI.

However, since the number of cases indicating the CDM group scheduled together may be large, a certain rule may be necessary. In this case, as an example, when the UE knows the antenna port based on the above-described Tables 13 to 18, the terminal may know the CDM group (or CDM pattern) to be used. However, since the above information is terminal specific information, it is not possible to know whether other terminals use different CDM groups (or CDM patterns). At this time, as described above, the CDM group may have a large number of individual bars and a method of using the CDM group. Therefore, this can be simplified to indicate only a certain case. In the following, specific embodiments of the present invention will be described based on the above.

Example (method of transmitting DMRS related information for V2X)

In relation to the V2X operation, as described above, in the base station scheduling mode (mode 3), semi-static information related to the DMRS may be transmitted to the terminal through the RRC, and the DMRS related dynamic configuration information may be transmitted through the DCI. In addition, in the UE autonomous determination mode (mode 4), UEs may determine semi-static information related to DMRS and exchange DMRS related dynamic configuration information through SCI, as described above.

In this case, the above-described DMRS related dynamic configuration information may include at least one of symbol number information, “co-scheduled CDM group” information, and DMRS antenna port information. However, in consideration of the number of cases in which the above-described information can be combined, the information to be transmitted increases, which may increase overhead. Therefore, in the case of using the side link, there may be a need for a scheme for configuring the above information in consideration of the overhead, the following embodiments will be described in detail.

Example 1

In Embodiment 1, all of “Number of DMRS CDM group (s) without data”, “DMRS port (s)” and “Number of front-load symbols” are considered as DMRS related dynamic configuration information included in DCI (or SCI). Can be. In this case, “Number of DMRS CDM group (s) without data” may be information on the above-described “co-scheduled CDM group”. In addition, "DMRS port (s)" may be the above-described DMRS antenna port. In addition, "Number of front-load symbols" may be information on available symbols of the above-described maximum symbols. In this case, for example, when using the side link, it may be considered that only the "Rank 1 transmission" transmitted by each UE using one antenna port without considering TX diversity. That is, in the above description, although a plurality of DMRS antenna ports may be used, a case of using one DMRS antenna port in consideration of only "Rank 1 transmission" may be considered.

For example, when the grouping (Platooning) is performed, the terminal that is the leader and the terminal that is not the leader may exist in the group (or cluster). In this case, it may be considered that two or more non-readers in the group transmit DMRS / data to the reader at the same time. In this case, however, TX diversity is not considered and each UE only transmits "Rank 1." Can be done. Transmission diversity may also be considered in V2X. However, in this case, a disadvantage may be greater due to performance deteriorated due to interference than gain obtained through transmission through a plurality of antennas. Therefore, as described above, in the present invention, it may be considered that each terminal performs only "Rank 1 transmission" transmitted using one antenna port.

For example, the group driving may be a service in which a plurality of non-leader terminals having the same direction / speed are driven in a group in the same lane as one leader terminal. In this case, since a plurality of vehicle terminals travel adjacent to each other, interference of DMRS may be greater than that of other environments. That is, in the case of cluster driving, the DMRS related information indication may be required to minimize the influence of interference between each other. As another example, a situation in which a plurality of non-reader terminals may send urgent data to the reader terminal may be considered. In this case, there is a need for a high reliability for processing urgent data in the group driving. Therefore, DMRSs transmitted by a plurality of non-reader terminals may also need an indication of DMRS-related information that may be orthogonal to each other and minimize the effects of interference. In consideration of the above situation, in the present invention, it may be considered that each terminal performs only "Rank 1 transmission" transmitted using one antenna port. However, as a specific example, the case is described based on the case of performing the group driving, but may not be limited thereto, and a DMRS related information indicating method may be set in consideration of an interference environment. Therefore, when transmitting DCI (or SCI), a table can be transmitted by considering only one DMRS antenna port, and the information can be transmitted by considering each DMRS configuration type and the maximum number of symbols. have. In this case, Table 19 may be information included in DCI when there is one maximum symbol in case of DMRS configuration type 1. Referring to Table 19, information may be configured by allocating a designated DMRS antenna port in each case based on the number of CDM groups used, and Tables 20 to 22 may be similar. At this time, in the case of Table 19 it may be composed of 3 bits.

 In addition, as an example, Table 20 may be a case where there are two maximum symbols when the DMRS configuration type is one. In this case, the information as shown in Table 20 may be configured based on the number of CDM groups and the number of available symbols among the maximum symbols. In this case, Table 20 may be configured with 4 bits.

In addition, as an example, Table 21 may be a case where there is one maximum symbol when the DMRS configuration type is 2, and Table 22 may be when a maximum symbol is two when the DMRS configuration type is 2. Table 21 may be configured with 4 bits, Table 22 may be configured with 5 bits, and may be the same as described above.

TABLE 19

TABLE 20

TABLE 21

Table 22

Example 1-1 (base station scheduling mode, mode 3)

The base station may transmit the information about the above-described tables 19 to 22 as the DMRS dynamic configuration information to the terminal through the DCI. For example, in the above-described cluster driving, the base station may transmit the information about the above-described tables 19 to 22 to the reader terminal through the DCI.

In this case, whether the maximum symbol is one or two and whether the DMRS configuration type is 1 or 2 may be transmitted to the terminal through the RRC as described above, as described above. For example, in the case of group driving, the maximum symbol and DMRS configuration type information may be transmitted not only to the reader terminal but also to the nonreader terminal through the RRC. That is, since the base station scheduling mode, both terminals can communicate with the base station through the downlink, the above information can be obtained through the RRC.

In this case, for example, in the case of group driving, the leader terminal and the non-reader terminal may have the same maximum symbol value and DMRS configuration type value. That is, terminals in the same cluster may be configured to have the same maximum symbol value and DMRS configuration type.

In addition, as an example, as described above, group ID information or identification information for distinguishing terminals in the same cluster may be transmitted to the terminal in order to set the maximum symbol value and the DMRS configuration type to be the same. That is, the terminals corresponding to the same cluster based on the same group ID or identification information may have the same maximum symbol value DMRS configuration type.

In addition, as an example, if the maximum symbol value and DMRS configuration type are determined in the cluster, the terminals in the cluster may maintain orthogonality as much as possible, thereby reducing the influence of interference.

After the terminal receives the DMRS dynamic configuration information based on Tables 19 to 22 from the base station through the DCI, the terminal may transmit the above-described information to another terminal in SCI for sidelink transmission. Thereafter, the terminal may perform sidelink communication based on the SCI information transmitted with the other terminal. That is, the SCI may be used to inform the receiving terminal (RX terminal) of DMRS related information used by the transmitting terminal (TX terminal). For example, in the case of group driving, the reader terminal may receive the information on Tables 19 to 22 described above from the base station through the DCI, and transmit the SCI information to the nonreader terminal based on the information. Thereafter, the reader terminal may transmit DMRS and data to the nonreader terminal through the sidelink.

Also, as an example, the above information may be information related to a DMRS used by a transmitting terminal. However, the receiving terminal that has received the DMRS and data from the transmitting terminal may also transmit the DMRS and data. Therefore, it is necessary to indicate not only the DMRS related information used by the transmitting terminal but also the DMRS related information used by the receiving terminal. In this case, as an example, DMRS related information used by the receiving terminal may be configured based on the information of Tables 19 to 22 described above. That is, two pairs of information may be configured based on the above-described Tables 19 to 22, DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal.

In this case, as an example, the above-described two pairs of information may be included in the DCI transmitted from the base station. That is, the base station may transmit a DCI including DMRS related information for each of the transmitting terminal and the receiving terminal. Thereafter, the transmitting terminal may transmit DMRS related information about each of the transmitting terminal and the receiving terminal to the receiving terminal based on the information included in the DCI. Through this, the receiving terminal can obtain the DMRS used by the transmitting terminal and the DMRS information used by the receiving terminal.

In addition, as an example, the DCI transmitted by the base station may include only DMRS related information about the transmitting terminal. When the transmitting terminal receives the DCI, the transmitting terminal may obtain its DMRS related information based on the received DCI information. The transmitting terminal may determine the DMRS-related information used by the receiving terminal based on the obtained DMRS-related information, and include the same in the SCI to transmit to the receiving terminal. That is, the SCI may include both DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal, and is not limited to the above-described embodiment.

In addition, as an example, as the DMRS related information obtained by the transmitting terminal through the DCI, the above-mentioned "Number of DMRS CDM group (s) without data" and "Number of front-load symbols" may be used in the same manner. That is, the DMRS related information used by the receiving terminal may be the same as other information, and may indicate only a DMRS antenna port. Accordingly, in the case of the maximum symbol 1 and the DMRS configuration type 1, only one value of 0 to 3 may be indicated as the DMRS antenna port. Or, for example, after a predetermined value (eg +1, +2, +3) is added to the DMRS antenna port used by the transmitting terminal, the module adds the above-mentioned value in the DMRS antenna port used by the transmitting terminal and then performs a modular operation. The receiving terminal can identify the DMRS antenna port (eg using modular 4).

Also, as an example, when the maximum symbol is 2 and DMRS configuration type 1, one of 0 to 7 may be indicated. Or, for example, the above-described value in the DMRS antenna port used by the transmitting terminal after indicating a constant value (eg +1, +2, +3, ..., +7) added to the DMRS antenna port used by the transmitting terminal. After adding, the receiver terminal can check the DMRS antenna port by performing a modular operation. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and DMRS configuration type 2, one of 0 to 5 may be indicated. Or, for example, after indicating a predetermined value (eg +1, +2, +3, +4, +5) added to the DMRS antenna port used by the transmitting terminal, the above-described value is used in the DMRS antenna port used by the transmitting terminal. In addition, the receiver terminal may check the DMRS antenna port by performing a modular operation. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and DMRS configuration type 2, one of 0 to 11 may be indicated. Or, for example, the above-described value in the DMRS antenna port used by the transmitting terminal after indicating a constant value (eg +1, +2, +3, ..., +11) added to the DMRS antenna port used by the transmitting terminal. After adding, the receiver terminal can check the DMRS antenna port by performing a modular operation. (e.g. using modular 12)

As another example, the receiving terminal may use "Number of DMRS CDM group (s) without data" and "Number of front-load symbols" obtained from information for DMRS used by the transmitting terminal. In this case, within the cluster driving, only the DMRS antenna port may be indicated according to the terminal unique number in the cluster. For example, the terminal unique number may be pre-configured to different values in advance for the terminals in the group driving.

Therefore, when the maximum symbol is 1 and the DMRS configuration type is 1, the DMRS antenna port used by the receiving terminal can be identified by adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. have. (e.g. using modular 4)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type is 1, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and the DMRS configuration type is 2, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type is 2, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 12)

In one example, the terminal unique number may be a terminal unique value based on Radio Network Temporary Identities (RNTI), or may be a terminal unique value defined only in a V2X cluster, but is not limited thereto. For example, a terminal unique value such as a Cyclic Redundancy Checking (CRC) value may be used instead of the terminal unique number.

In this case, as an example, each V2X cluster may be composed of a plurality of vehicle terminals that travel with the same direction / speed in the same lane. The two nearest terminals in one cluster have a fixed distance and other terminals cannot be located between them. In this case, the V2X cluster may be a group of V2X terminals composed of one leader terminal and a plurality of non-leader terminals along the leader terminal in cluster driving.

The unique number for each V2X cluster may be indicated by higher level signaling such as RRC or calculated based on the terminal unique number of the reader terminal. The terminal unique value defined only in one V2X cluster is indicated by higher level signaling such as RRC, or after adding a unique number for the V2X cluster to the terminal unique value such as RNTI or CRC, and then a V2X cluster. It may be calculated by performing a modular operation on the number of all terminals belonging to.

Example 1-2 (terminal autonomous determination mode, mode 4)

As described above, in the UE autonomous determination mode, the UE may not receive signaling from the base station. Accordingly, the terminal may directly determine the information about Tables 19 to 22 described above. In addition, as an example, the terminal may determine the information on Tables 19 to 22 described above based on a pre-configuration scheme. That is, in the base station scheduling mode, DMRS-related information such as the information about Tables 19 to 22 described above is indicated as DCI from the base station to the V2X transmitting (TX) terminal. On the other hand, in the UE autonomous determination mode, the V2X transmitting (TX) terminal may determine DMRS related information such as the information about Tables 19 to 22 according to a preset method which will be described later. In addition, the V2X transmitting (TX) terminal transmits the determined information to the V2X receiving (RX) terminal, and through this process, the V2X transmitting (TX) terminal and / or the V2X receiving (RX) terminal transmits the DMRS.

In this case, as an example of a preset method, a value of “Number of DMRS CDM group (s) without data” may be preset according to the number of all terminals to be clustered. As another example, when there are many terminals in a cluster, "Number of DMRS CDM group (s) without data" may be determined as a large value. That is, it may be assumed that there are always many CDM groups used.

As another example, the value of "Number of front-load symbols" may be preset according to the terminal speed during group driving. For example, when the speed is greater than or equal to a certain level, two symbols may be used. Otherwise, one symbol may be used, but is not limited to the above-described embodiment.

  Also, for example, "Number of DMRS CDM group (s) without data" and "Number of front-load symbols" may be identical in a cluster. In this case, as an example, the DMRS antenna ports may be randomly determined. In this case, as an example, the DMRS antenna port may be randomly determined based on a UE unique number or a Cyclic Redundancy Checking (CRC) value. As another example, the DMRS antenna port may fixedly use a specific port. For example, the specific port may be port 0.

In addition, as an example, the information configuration method may be preset in consideration of the case where one or two maximum symbols and one or two DMRS configuration types are set.

In this case, as an example, as described above, in the case of group driving, the leader terminal and the non-reader terminal may have the same maximum symbol value and DMRS configuration type.

In this case, whether the maximum symbol is one or two, and whether the DMRS configuration type is 1 or 2 may be preset according to the number of all terminals during cluster driving. More specifically, when the maximum symbol is one, and the DMRS configuration type is 1, up to four terminals can be distinguished. In addition, when there are two maximum symbols and the DMRS configuration type is 1, up to eight terminals can be distinguished. In addition, when the maximum symbol is one and the DMRS configuration type is 2, up to six terminals may be distinguished. In addition, when there are two maximum symbols and the DMRS configuration type is 2, up to 12 terminals can be distinguished.

Accordingly, the maximum symbol value and the DMRS configuration type may be determined according to a preset method in consideration of the number of terminals included in the cluster.

As another example, the maximum symbol value and the DMRS configuration type may be preset based on the speed of the group driving.

As an example, when the speed of the cluster is greater than or equal to a certain speed, two maximum symbols may be determined. In this case, the constant speed may be a critical speed and may have a constant error.

Based on the above, the UE operating in mode 4 may determine the maximum symbol value and the DMRS configuration type. Thereafter, the terminal may transmit the above-described information about Tables 19 to 22 to another terminal through SCI. That is, the transmitting terminal may inform the receiving terminal of DMRS related information used by the transmitting terminal through SCI, and may perform sidelink communication based on the information. For example, during clustering, the transmitting terminal may be a reader terminal, and the receiving terminal may be a non-reader terminal.

In addition, as an example, as described above, there is a need to confirm the DMRS used by the receiving terminal. In this case, in the case of group driving, the case where the leader terminal is the transmitting terminal and the non-reader terminal is the receiving terminal may be considered.

At this time, the receiving terminal receiving the DMRS and data from the transmitting terminal may also transmit the DMRS and data. Therefore, it is necessary to indicate not only the DMRS related information used by the transmitting terminal but also the DMRS related information used by the receiving terminal. For example, DMRS related information used by the receiving terminal may be configured based on the information of Tables 19 to 22 described above. That is, two pairs of information may be configured based on the above-described Table 19 to Table 22, DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal.

In addition, as an example, the above-mentioned "Number of DMRS CDM group (s) without data" and "Number of front-load symbols" as the DMRS-related information determined by the transmitting terminal may also be used in the receiving terminal. That is, the DMRS related information used by the receiving terminal may be the same as other information, and may indicate only a DMRS antenna port.

Accordingly, in the case of the maximum symbol 1 and the DMRS configuration type 1, only one value of 0 to 3 may be indicated as the DMRS antenna port. Or, for example, after a predetermined value (eg +1, +2, +3) is added to the DMRS antenna port used by the transmitting terminal, the module adds the above-mentioned value in the DMRS antenna port used by the transmitting terminal and then performs a modular operation. The receiving terminal can identify the DMRS antenna port (eg using modular 4).

Also, as an example, when the maximum symbol is 2 and DMRS configuration type 1, one of 0 to 7 may be indicated. Or, for example, the above-described value in the DMRS antenna port used by the transmitting terminal after indicating a constant value (eg +1, +2, +3, ..., +7) added to the DMRS antenna port used by the transmitting terminal. After adding, the receiver terminal can check the DMRS antenna port by performing a modular operation. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and DMRS configuration type 2, one of 0 to 5 may be indicated. Or, for example, after indicating a predetermined value (eg +1, +2, +3, +4, +5) added to the DMRS antenna port used by the transmitting terminal, the above-described value is used in the DMRS antenna port used by the transmitting terminal. In addition, the receiver terminal may check the DMRS antenna port by performing a modular operation. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and DMRS configuration type 2, one of 0 to 11 may be indicated. Or, for example, the above-described value in the DMRS antenna port used by the transmitting terminal after indicating a constant value (eg +1, +2, +3, ..., +11) added to the DMRS antenna port used by the transmitting terminal. After adding, the receiver terminal can check the DMRS antenna port by performing a modular operation. (e.g. using modular 12)

As another example, the receiving terminal may use "Number of DMRS CDM group (s) without data" and "Number of front-load symbols" obtained from information for DMRS used by the transmitting terminal. In this case, within the cluster driving, only the DMRS antenna port may be indicated according to the terminal unique number in the cluster. For example, the terminal unique number may be pre-configured to different values in advance for the terminals in the group driving.

Therefore, when the maximum symbol is 1 and the DMRS configuration type is 1, the DMRS antenna port used by the receiving terminal can be identified by adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. have. (e.g. using modular 4)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type is 1, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and the DMRS configuration type is 2, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type is 2, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 12)

In one example, the terminal unique number may be a terminal unique value based on Radio Network Temporary Identities (RNTI), or may be a terminal unique value defined only in a V2X cluster, but is not limited thereto. For example, a terminal unique value such as a Cyclic Redundancy Checking (CRC) value may be used instead of the terminal unique number.

In this case, as an example, each V2X cluster may be composed of a plurality of vehicle terminals that travel with the same direction / speed in the same lane. The two nearest terminals in one cluster have a fixed distance and other terminals cannot be located between them. In this case, the V2X cluster may be a group of V2X terminals composed of one leader terminal and a plurality of non-leader terminals along the leader terminal in cluster driving.

The unique number for each V2X cluster may be indicated by higher level signaling such as RRC or calculated based on the terminal unique number of the reader terminal. The terminal unique value defined only in one V2X cluster is indicated by higher level signaling such as RRC, or after adding a unique number for the V2X cluster to the terminal unique value such as RNTI or CRC, and then a V2X cluster. It may be calculated by performing a modular operation on the number of all terminals belonging to.

Meanwhile, as an example, Example 1-1 and Example 1-2 may be embodiments associated with each other. That is, the terminal may operate based on the above-described embodiments 1-1 and 1-2 based on the set mode and may be embodiments related to each other.

Example 2

In Embodiment 2, both "Number of DMRS CDM group (s) without data", "DMRS port (s)", and "Number of front-load symbols" are considered as DMRS-related dynamic configuration information included in DCI (or SCI). Can be. In this case, "Number of DMRS CDM group (s) without data" may be information on the above-described co-scheduled CDM group. In addition, the DMRS port (s) may be the above-described DMRS antenna port. In addition, "Number of front-load symbols" may be information on available symbols of the above-described maximum symbols. In this case, for example, when using the side link, it may be considered that only the "Rank 1 transmission" transmitted by each UE using one antenna port without considering TX diversity. That is, in the above description, although a plurality of DMRS antenna ports may be used, a case of using one DMRS antenna port in consideration of only "Rank 1 transmission" may be considered.

For example, when the grouping (Platooning) is performed, the terminal that is the leader and the terminal that is not the leader may exist in the group (or cluster). In this case, it may be considered that two or more non-readers in the group transmit DMRS / data to the reader at the same time. In this case, however, TX diversity is not considered and each UE only transmits "Rank 1." Can be done. Transmission diversity may also be considered in V2X. However, in this case, a disadvantage may be greater due to performance deteriorated due to interference than gain obtained through transmission through a plurality of antennas. Therefore, as described above, in the present invention, it may be considered that each terminal performs only "Rank 1 transmission" transmitted using one antenna port.

For example, the group driving may be a service in which a plurality of non-leader terminals having the same direction / speed are driven in a group in the same lane as one leader terminal. In this case, since a plurality of vehicle terminals travel adjacent to each other, interference of DMRS may be greater than that of other environments. That is, in the case of cluster driving, the DMRS related information indication may be required to minimize the influence of interference between each other. As another example, a situation in which a plurality of non-reader terminals may send urgent data to the reader terminal may be considered. In this case, there is a need for a high reliability for processing urgent data in the group driving. Therefore, DMRSs transmitted by a plurality of non-reader terminals may also need an indication of DMRS-related information that may be orthogonal to each other and minimize the effects of interference. In consideration of the above situation, in the present invention, it may be considered that each terminal performs only "Rank 1 transmission" transmitted using one antenna port. However, as a specific example, the case is described based on the case of performing the group driving, but may not be limited thereto, and a DMRS related information indicating method may be set in consideration of an interference environment.

Accordingly, when transmitting DCI (or SCI), a table may be transmitted by considering only one DMRS antenna port and transmitting information. Also, as an example, in the DMRS configuration type 1, “Number of DMRS CDM group (s) without data” is always 2, and in the DMRS configuration type 2, it may always be determined as 3. That is, the case where the CDM group is always used to the maximum may be considered. Through this, the size of information included in the DCI (or SCI) can be reduced, thereby reducing overhead.

Therefore, considering each type and the maximum number of symbols it may be as shown in Tables 23 to 26. In this case, Tables 23 to 26 may be configured in a simpler table than Tables 19 to 22 described above. In this case, Table 23 may be information included in DCI (or SCI) when there is one maximum symbol in case of DMRS configuration type 1. Referring to Table 23, the number of CDM groups (groups) used may be a maximum of 2, so that information may be configured by allocating a designated DMRS antenna port, and Tables 23 to 26 may be similar. In this case, Table 23 may be composed of 2 bits.

In addition, as an example, Table 24 may be the case where the maximum symbol is two when the DMRS configuration type is 1. In this case, in Table 24, the maximum number of CDM groups is 2, and information may be configured based on the number of available symbols. In this case, the table 24 may be configured with 4 bits. In addition, Table 25 may be a case where there is one maximum symbol when the DMRS configuration type is two, and Table 26 may be when a maximum symbol is two when the DMRS configuration type is two. Table 25 may be configured with 4 bits, and Table 26 may be configured with 5 bits.

TABLE 23

TABLE 24

TABLE 25

TABLE 26

Example 2-1 (base station scheduling mode, mode 3)

The base station may transmit the information on Tables 23 to 26 described above as the DMRS dynamic configuration information to the terminal through the DCI. For example, in the above-described cluster driving, the base station may transmit the information about the above Tables 23 to 26 through the DCI to the reader terminal.

In this case, whether the maximum symbol is one or two and whether the DMRS configuration type is 1 or 2 may be transmitted to the terminal through the RRC as described above, as described above. For example, in the case of group driving, the maximum symbol and DMRS configuration type information may be transmitted not only to the reader terminal but also to the nonreader terminal through the RRC. That is, since the base station scheduling mode, both terminals can communicate with the base station through the downlink, the above information can be obtained through the RRC.

In this case, for example, in the case of group driving, the leader terminal and the non-reader terminal may have the same maximum symbol value and DMRS configuration type value. That is, terminals in the same cluster may be configured to have the same maximum symbol value and DMRS configuration type.

In addition, as an example, as described above, group ID information or identification information for distinguishing terminals in the same cluster may be transmitted to the terminal in order to set the maximum symbol value and the DMRS configuration type to be the same. That is, the terminals corresponding to the same cluster based on the same group ID or identification information may have the same maximum symbol value DMRS configuration type.

In addition, as an example, if the maximum symbol value and DMRS configuration type are determined in the cluster, the terminals in the cluster may maintain orthogonality as much as possible, thereby reducing the influence of interference.

After the terminal receives the DMRS dynamic configuration information based on Tables 23 to 26 from the base station through the DCI, the terminal may transmit the above-described information to another terminal in SCI for sidelink transmission. Thereafter, the terminal may perform sidelink communication based on the SCI information transmitted with the other terminal. That is, the SCI may be used to inform the receiving terminal (RX terminal) of DMRS related information used by the transmitting terminal (TX terminal). For example, in the case of group driving, the reader terminal may receive the information about Tables 23 to 26 described above from the base station through the DCI, and transmit the SCI information to the nonreader terminal based on the information. Thereafter, the reader terminal may transmit DMRS and data to the nonreader terminal through the sidelink.

Also, as an example, the above information may be information related to a DMRS used by a transmitting terminal. However, the receiving terminal that has received the DMRS and data from the transmitting terminal may also transmit the DMRS and data. Therefore, it is necessary to indicate not only the DMRS related information used by the transmitting terminal but also the DMRS related information used by the receiving terminal. In this case, as an example, DMRS related information used by the receiving terminal may be configured based on the information of Tables 23 to 26 described above. That is, two pairs of information may be configured based on the above-described Tables 23 to 26, DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal.

In this case, as an example, the above-described two pairs of information may be included in the DCI transmitted from the base station. That is, the base station may transmit a DCI including DMRS related information for each of the transmitting terminal and the receiving terminal. Thereafter, the transmitting terminal may transmit DMRS related information about each of the transmitting terminal and the receiving terminal to the receiving terminal based on the information included in the DCI. Through this, the receiving terminal can obtain the DMRS used by the transmitting terminal and the DMRS information used by the receiving terminal.

In addition, as an example, the DCI transmitted by the base station may include only DMRS related information about the transmitting terminal. When the transmitting terminal receives the DCI, the transmitting terminal may obtain its DMRS related information based on the received DCI information. The transmitting terminal may determine the DMRS-related information used by the receiving terminal based on the obtained DMRS-related information, and include the same in the SCI to transmit to the receiving terminal. That is, the SCI may include both DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal, and is not limited to the above-described embodiment.

In addition, as an example, the receiver terminal may use the above-mentioned "Number of front-load symbols" as DMRS-related information obtained by the transmitter terminal through the DCI. For example, “Number of DMRS CDM group (s) without data” is determined based on the DMRS configuration type as described above, and thus may not be considered. That is, the DMRS related information used by the receiving terminal may be the same as other information, and may indicate only a DMRS antenna port.

Therefore, in the case of the maximum symbol 1 and the DMRS configuration type 1, only one value of 0 to 3 may be indicated. Or, for example, after a predetermined value (eg +1, +2, +3) is added to the DMRS antenna port used by the transmitting terminal, the module adds the above-mentioned value in the DMRS antenna port used by the transmitting terminal and then performs a modular operation. The receiving terminal can identify the DMRS antenna port (eg using modular 4).

Also, as an example, when the maximum symbol is 2 and DMRS configuration type 1, one of 0 to 7 may be indicated. Or, for example, the above-described value in the DMRS antenna port used by the transmitting terminal after indicating a constant value (eg +1, +2, +3, ..., +7) added to the DMRS antenna port used by the transmitting terminal. After adding, the receiver terminal can check the DMRS antenna port by performing a modular operation. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and DMRS configuration type 2, one of 0 to 5 may be indicated. Or, for example, after indicating a predetermined value (eg +1, +2, +3, +4, +5) added to the DMRS antenna port used by the transmitting terminal, the above-described value is used in the DMRS antenna port used by the transmitting terminal. In addition, the receiver terminal may check the DMRS antenna port by performing a modular operation. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and DMRS configuration type 2, one of 0 to 11 may be indicated. Or, for example, the above-described value in the DMRS antenna port used by the transmitting terminal after indicating a constant value (eg +1, +2, +3, ..., +11) added to the DMRS antenna port used by the transmitting terminal. After adding, the receiver terminal can check the DMRS antenna port by performing a modular operation. (e.g. using modular 12)

As another example, the receiving terminal may use the same number of front-load symbols in the information obtained from the information for the DMRS used by the transmitting terminal. For example, “Number of DMRS CDM group (s) without data” is determined based on the DMRS configuration type as described above, and thus may not be considered. In this case, within the cluster driving, only the DMRS antenna port may be indicated according to the terminal unique number in the cluster. For example, the terminal unique number may be pre-configured to different values in advance for the terminals in the group driving.

Therefore, when the maximum symbol is 1 and the DMRS configuration type is 1, the DMRS antenna port used by the receiving terminal can be identified by adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. have. (e.g. using modular 4)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type is 1, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and the DMRS configuration type is 2, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type is 2, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 12)

In one example, the terminal unique number may be a terminal unique value based on Radio Network Temporary Identities (RNTI), or may be a terminal unique value defined only in a V2X cluster, but is not limited thereto. For example, a terminal unique value such as a Cyclic Redundancy Checking (CRC) value may be used instead of the terminal unique number.

In this case, as an example, each V2X cluster may be composed of a plurality of vehicle terminals that travel with the same direction / speed in the same lane. The two nearest terminals in one cluster have a fixed distance and other terminals cannot be located between them. In this case, the V2X cluster may be a group of V2X terminals composed of one leader terminal and a plurality of non-leader terminals along the leader terminal in cluster driving.

The unique number for each V2X cluster may be indicated by higher level signaling such as RRC or calculated based on the terminal unique number of the reader terminal. The terminal unique value defined only in one V2X cluster is indicated by higher level signaling such as RRC, or after adding a unique number for the V2X cluster to the terminal unique value such as RNTI or CRC, and then a V2X cluster. It may be calculated by performing a modular operation on the number of all terminals belonging to.

Example 2-2 (terminal autonomous determination mode, mode 4)

As described above, in the UE autonomous determination mode, the UE may not receive signaling from the base station. Accordingly, the terminal may directly determine the information about Tables 23 to 26 described above. In addition, as an example, the terminal may determine the information on Tables 23 to 26 described above based on a pre-configuration scheme.

That is, in the base station scheduling mode, DMRS related information such as the above-described information about Tables 23 to 26 is indicated as DCI from the base station to the V2X transmitting (TX) terminal. On the other hand, in the UE autonomous determination mode, the V2X transmitting (TX) terminal may determine DMRS related information such as the information about Tables 23 to 26 according to a preset method to be described later. In addition, the V2X transmitting (TX) terminal transmits the determined information to the V2X receiving (RX) terminal, and through this process, the V2X transmitting (TX) terminal and / or the V2X receiving (RX) terminal transmits the DMRS.

As an example of a preset method, a value of "Number of front-load symbols" may be preset according to the terminal speed during group driving. For example, when the speed is constant, two symbols may be used. Otherwise, one symbol may be used, but is not limited to the above-described embodiment.

  As another example, "Number of front-load symbols" in the cluster may be the same. For example, “Number of DMRS CDM group (s) without data” is determined based on the DMRS configuration type as described above, and thus may not be considered. At this time, the DMRS antenna port may be randomly determined. In this case, as an example, the DMRS antenna port may be randomly determined based on a UE unique number or a Cyclic Redundancy Checking (CRC) value. As another example, the DMRS antenna port may fixedly use a specific port. For example, the specific port may be port 0.

In addition, as an example, the information configuration method may be preset in consideration of the case where one or two maximum symbols and one or two DMRS configuration types are set.

In this case, as an example, as described above, in the case of group driving, the leader terminal and the non-reader terminal may have the same maximum symbol value and DMRS configuration type.

In this case, whether the maximum symbol is one or two and whether the DMRS configuration type is 1 or 2 may be preset according to the number of all terminals during cluster driving. More specifically, when the maximum symbol is one, and the DMRS configuration type is 1, up to four terminals can be distinguished. In addition, when there are two maximum symbols and the DMRS configuration type is 1, up to eight terminals can be distinguished. In addition, when the maximum symbol is one and the DMRS configuration type is 2, up to six terminals may be distinguished. In addition, when there are two maximum symbols and the DMRS configuration type is 2, up to 12 terminals can be distinguished.

Accordingly, the maximum symbol value and the DMRS configuration type may be determined according to a preset method in consideration of the number of terminals included in the cluster.

As another example, the maximum symbol value and the DMRS configuration type may be preset based on the speed of the group driving.

As an example, when the speed of the cluster is greater than or equal to a certain speed, two maximum symbols may be determined. In this case, the constant speed may be a critical speed and may have a constant error.

Based on the above description, the UE operating in mode 4 may determine the maximum symbol value and the DMRS configuration type. Thereafter, the terminal may transmit the above-described information about Tables 22 to 26 to another terminal through SCI. That is, the transmitting terminal may inform the receiving terminal of the DMRS related information used by the transmitting terminal through SCI, and may perform sidelink communication based on the information. For example, during clustering, the transmitting terminal may be a reader terminal, and the receiving terminal may be a nonreader terminal.

In addition, as an example, as described above, there is a need to confirm the DMRS used by the receiving terminal. In this case, in the case of group driving, the case where the leader terminal is the transmitting terminal and the non-reader terminal is the receiving terminal may be considered.

At this time, the receiving terminal receiving the DMRS and data from the transmitting terminal may also transmit the DMRS and data. Therefore, it is necessary to indicate not only the DMRS related information used by the transmitting terminal but also the DMRS related information used by the receiving terminal. For example, DMRS-related information used by the receiving terminal may be configured based on the information of Tables 22 to 26 described above. That is, two pairs of DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal may be configured based on the aforementioned Tables 22 to 26.

In addition, as an example, the above-mentioned "Number of front-load symbols" may be used by the receiving terminal as DMRS related information determined by the transmitting terminal. For example, “Number of DMRS CDM group (s) without data” is determined based on the DMRS configuration type as described above, and thus may not be considered. That is, the DMRS related information used by the receiving terminal may be the same as other information, and may indicate only a DMRS antenna port. Therefore, in the case of the maximum symbol 1 and the DMRS configuration type 1, only one value of 0 to 3 may be indicated. Or, for example, after a predetermined value (eg +1, +2, +3) is added to the DMRS antenna port used by the transmitting terminal, the module adds the above-mentioned value in the DMRS antenna port used by the transmitting terminal and then performs a modular operation. The receiving terminal can identify the DMRS antenna port (eg using modular 4).

Also, as an example, when the maximum symbol is 2 and DMRS configuration type 1, one of 0 to 7 may be indicated. Or, for example, the above-described value in the DMRS antenna port used by the transmitting terminal after indicating a constant value (eg +1, +2, +3, ..., +7) added to the DMRS antenna port used by the transmitting terminal. After adding, the receiver terminal can check the DMRS antenna port by performing a modular operation. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and DMRS configuration type 2, one of 0 to 5 may be indicated. Or, for example, after indicating a predetermined value (eg +1, +2, +3, +4, +5) added to the DMRS antenna port used by the transmitting terminal, the above-described value is used in the DMRS antenna port used by the transmitting terminal. In addition, the receiver terminal may check the DMRS antenna port by performing a modular operation. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and DMRS configuration type 2, one of 0 to 11 may be indicated. Or, for example, the above-described value in the DMRS antenna port used by the transmitting terminal after indicating a constant value (eg +1, +2, +3, ..., +11) added to the DMRS antenna port used by the transmitting terminal. After adding, the receiver terminal can check the DMRS antenna port by performing a modular operation. (e.g. using modular 12)

As another example, the receiving terminal may use the same "Number of front-load symbols" obtained from the information for the DMRS used by the transmitting terminal. For example, “Number of DMRS CDM group (s) without data” is determined based on the DMRS configuration type as described above, and thus may not be considered. In this case, within the cluster driving, only the DMRS antenna port may be indicated according to the terminal unique number in the cluster. For example, the terminal unique number may be pre-configured with different values in advance for the terminals in the group driving.

Therefore, when the maximum symbol is 1 and the DMRS configuration type is 1, the DMRS antenna port used by the receiving terminal can be identified by adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. have. (e.g. using modular 4)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type is 1, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and the DMRS configuration type is 2, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type is 2, a DMRS antenna port used by the receiving terminal by performing a modular operation after adding a constant value based on the terminal unique number to the DMRS antenna port used by the transmitting terminal. You can check. (e.g. using modular 12)

In one example, the terminal unique number may be a terminal unique value based on Radio Network Temporary Identities (RNTI), or may be a terminal unique value defined only in a V2X cluster, but is not limited thereto. For example, a terminal unique value such as a Cyclic Redundancy Checking (CRC) value may be used instead of the terminal unique number.

In this case, as an example, each V2X cluster may be composed of a plurality of vehicle terminals that travel with the same direction / speed in the same lane. The two nearest terminals in one cluster have a fixed distance and other terminals cannot be located between them. In this case, the V2X cluster may be a group of V2X terminals composed of one leader terminal and a plurality of non-leader terminals along the leader terminal in cluster driving.

The unique number for each V2X cluster may be indicated by higher level signaling such as RRC or calculated based on the terminal unique number of the reader terminal. The terminal unique value defined only in one V2X cluster is indicated by higher level signaling such as RRC, or after adding a unique number for the V2X cluster to the terminal unique value such as RNTI or CRC, and then a V2X cluster. It may be calculated by performing a modular operation on the number of all terminals belonging to.

Meanwhile, as an example, Example 2-1 and Example 2-2 may be embodiments associated with each other. That is, the terminal may operate based on the above-described embodiments 2-1 and 2-2 based on the set mode and may be embodiments related to each other.

Example 3

In Embodiment 3, only DMRS multiplexing values may be indicated. In Embodiment 3, only DMRS multiplexing values may be provided without indicating information about the number of CDM groups and the number of available symbols among the maximum symbols. That is, in the third embodiment, the number of other cases may be excluded in consideration of only the interference minimization, and only the values in which the DMRS is multiplexed may be indicated to include less information in the DCI (or SCI) than the first and second embodiments. . In addition, in the case of using the side link in the third embodiment, it is possible to consider that only the "Rank 1 transmission" transmitted by each terminal using one antenna port without considering TX diversity. That is, in the above description, although a plurality of DMRS antenna ports may be used, a case of using one DMRS antenna port in consideration of only "Rank 1 transmission" may be considered.

For example, when the grouping (Platooning) is performed, the terminal that is the leader and the terminal that is not the leader may exist in the group (or cluster). In this case, it may be considered that two or more non-readers in the group transmit DMRS / data to the reader at the same time. In this case, however, TX diversity is not considered and each UE only transmits "Rank 1." Can be done.

Transmission diversity may also be considered in V2X. However, in this case, a disadvantage may be greater due to performance deteriorated due to interference than gain obtained through transmission through a plurality of antennas. Therefore, as described above, in the present invention, it may be considered that each terminal performs only "Rank 1 transmission" transmitted using one antenna port.

For example, the group driving may be a service in which a plurality of non-leader terminals having the same direction / speed are driven in a group in the same lane as one leader terminal. In this case, since a plurality of vehicle terminals travel adjacent to each other, interference of DMRS may be greater than that of other environments. That is, in the case of cluster driving, the DMRS related information indication may be required to minimize the influence of interference between each other. As another example, a situation in which a plurality of non-reader terminals may send urgent data to the reader terminal may be considered. In this case, there is a need for a high reliability for processing urgent data in the group driving. Therefore, DMRSs transmitted by a plurality of non-reader terminals may also need an indication of DMRS-related information that may be orthogonal to each other and minimize the effects of interference. In consideration of the above situation, in the present invention, it may be considered that each terminal performs only "Rank 1 transmission" transmitted using one antenna port. However, as a specific example, the case is described based on the case of performing the group driving, but may not be limited thereto, and a DMRS related information indicating method may be set in consideration of an interference environment.

Accordingly, when transmitting DCI (or SCI), a table may be transmitted by considering only one DMRS antenna port and transmitting information.

Therefore, considering the number of symbols and the type of DMRS configuration, it may be as shown in Tables 27 to 30 below. In this case, Tables 27 to 30 may be configured in a simpler table than Tables 23 to 26 described above. In this case, Table 27 may be information included in DCI (or SCI) when there is one maximum symbol in case of DMRS configuration type 1. Referring to Table 27, there is only one symbol and includes only DMRS multiplexing values used when the DMRS configuration type is 1. Therefore, it can contain four values as the maximum case.

In addition, as an example, Table 28 may be a case where there are two maximum symbols when the DMRS configuration type is one. In this case, in Table 28, two symbols are used to include a maximum of eight values. In addition, Table 29 may be a case where there is one maximum symbol when the DMRS configuration type is 2, and Table 30 may be when a maximum symbol is two when the DMRS configuration type is 2. Table 29 may include six values as the maximum case and Table 30 may include 12 values as the maximum case.

TABLE 27

TABLE 28

TABLE 29

TABLE 30

Example 3-1 (base station scheduling mode, mode 3)

The base station may transmit the information on Tables 27 to 30 described above as the DMRS dynamic configuration information to the terminal through the DCI. For example, in the above-described cluster driving, the base station may transmit the information about the above-described tables 27 to 30 to the reader terminal through the DCI.

In this case, whether the maximum symbol is one or two and whether the DMRS configuration type is 1 or 2 may be transmitted to the terminal through the RRC as described above, as described above. For example, in the case of group driving, the maximum symbol and DMRS configuration type information may be transmitted not only to the reader terminal but also to the nonreader terminal through the RRC. That is, since the base station scheduling mode, both terminals can communicate with the base station through the downlink, the above information can be obtained through the RRC.

In this case, for example, in the case of group driving, the leader terminal and the non-reader terminal may have the same maximum symbol value and DMRS configuration type value. That is, terminals in the same cluster may be configured to have the same maximum symbol value and DMRS configuration type.

In addition, as an example, as described above, group ID information or identification information for distinguishing terminals in the same cluster may be transmitted to the terminal in order to set the maximum symbol value and the DMRS configuration type to be the same. That is, the terminals corresponding to the same cluster based on the same group ID or identification information may have the same maximum symbol value DMRS configuration type.

In addition, as an example, if the maximum symbol value and DMRS configuration type are determined in the cluster, the terminals in the cluster may maintain orthogonality as much as possible, thereby reducing the influence of interference.

After the terminal receives the DMRS dynamic configuration information based on Tables 27 to 30 from the base station through the DCI, the terminal may transmit the above-described information to the other terminal in SCI for sidelink transmission. Thereafter, the terminal may perform sidelink communication based on the SCI information transmitted with the other terminal. That is, the SCI may be used to inform the receiving terminal (RX terminal) of DMRS related information used by the transmitting terminal (TX terminal). For example, in the case of group driving, the reader terminal may receive the information on Tables 27 to 30 described above from the base station through the DCI, and transmit the SCI information to the nonreader terminal based on the information. Thereafter, the reader terminal may transmit DMRS and data to the nonreader terminal through the sidelink.

Also, as an example, the above information may be information related to a DMRS used by a transmitting terminal. However, the receiving terminal that has received the DMRS and data from the transmitting terminal may also transmit the DMRS and data. Therefore, it is necessary to indicate not only the DMRS related information used by the transmitting terminal but also the DMRS related information used by the receiving terminal. In this case, as an example, DMRS related information used by the receiving terminal may be configured based on the information of Tables 27 to 30 described above. That is, two pairs of information may be configured based on DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal based on the aforementioned Tables 27 to 30.

In this case, as an example, the above-described two pairs of information may be included in the DCI transmitted from the base station. That is, the base station may transmit a DCI including DMRS related information for each of the transmitting terminal and the receiving terminal. Thereafter, the transmitting terminal may transmit DMRS related information about each of the transmitting terminal and the receiving terminal to the receiving terminal based on the information included in the DCI. Through this, the receiving terminal can obtain the DMRS used by the transmitting terminal and the DMRS information used by the receiving terminal.

In addition, as an example, the DCI transmitted by the base station may include only DMRS related information about the transmitting terminal. When the transmitting terminal receives the DCI, the transmitting terminal may obtain its DMRS related information based on the received DCI information. The transmitting terminal may determine the DMRS-related information used by the receiving terminal based on the obtained DMRS-related information, and include the same in the SCI to transmit to the receiving terminal. That is, the SCI may include both DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal, and is not limited to the above-described embodiment.

In addition, as an example, the DMRS-related information used by the receiving terminal as DMRS-related information obtained by the transmitting terminal through DCI may be identical to other information, and may indicate only a DMRS antenna port. In this case, different values may be preset according to the unique numbers of the terminals in the group driving. Accordingly, the DMRS antenna port may be indicated based on the above-described predetermined value.

For example, in the case of the maximum symbol 1 and the DMRS configuration type 1, a specific value (eg +1, +2, +3) is added to the DMRS antenna port used by the transmitting terminal, and then described in the DMRS antenna port used by the transmitting terminal. After adding a value, the receiver terminal may check the DMRS antenna port by performing a modular operation (eg using modular 4).

In addition, as an example, when the maximum symbol is 2 and DMRS configuration type 1, a predetermined value (eg +1, +2, +3, ..., +7) is added to the DMRS antenna port used by the transmitting terminal. After that, the DMRS antenna port used by the transmitting terminal adds the above-described values, and then performs a modular operation so that the receiving terminal can identify the DMRS antenna port. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and DMRS configuration type 2, a constant value (eg +1, +2, +3, +4, +) is added to the DMRS antenna port used by the transmitting terminal to perform a modular operation. After instructing 5), the receiver terminal can identify the DMRS antenna port by adding the above-described values in the DMRS antenna port used by the transmitter terminal. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type 2, a predetermined value (eg +1, +2, +3, ..., +11) is added to the DMRS antenna port used by the transmitting terminal. After that, the DMRS antenna port used by the transmitting terminal adds the above-described values, and then performs a modular operation so that the receiving terminal can identify the DMRS antenna port. (e.g. using modular 12)

In one example, the terminal unique number may be a terminal unique value based on Radio Network Temporary Identities (RNTI), or may be a terminal unique value defined only in a V2X cluster, but is not limited thereto. For example, a terminal unique value such as a Cyclic Redundancy Checking (CRC) value may be used instead of the terminal unique number.

In this case, as an example, each V2X cluster may be composed of a plurality of vehicle terminals that travel with the same direction / speed in the same lane. The two nearest terminals in one cluster have a fixed distance and other terminals cannot be located between them. In this case, the V2X cluster may be a group of V2X terminals composed of one leader terminal and a plurality of non-leader terminals along the leader terminal in cluster driving.

The unique number for each V2X cluster may be indicated by higher level signaling such as RRC or calculated based on the terminal unique number of the reader terminal. The terminal unique value defined only in one V2X cluster is indicated by higher level signaling such as RRC, or after adding a unique number for the V2X cluster to the terminal unique value such as RNTI or CRC, and then a V2X cluster. It may be calculated by performing a modular operation on the number of all terminals belonging to.

Example 3-2 (terminal autonomous determination mode, mode 4)

As described above, in the UE autonomous determination mode, the UE may not receive signaling from the base station. Therefore, the terminal can directly determine the information about the above Tables 27 to 30. In addition, as an example, the terminal may determine the information on Tables 27 to 30 described above based on a pre-configuration scheme. That is, in the base station scheduling mode, if DMRS related information such as the information about Tables 27 to 30 is indicated as DCI from the base station to the V2X transmitting (TX) terminal, in the terminal autonomous determination mode according to a predetermined method to be described later, DM2 related information such as information on Table 30 is determined by the V2X transmitting (TX) terminal itself. In addition, the V2X transmitting (TX) terminal transmits the determined information to the V2X receiving (RX) terminal, and through this process, the V2X transmitting (TX) terminal and / or the V2X receiving (RX) terminal transmits the DMRS.

In this case, as an example of a preset method, other DMRS-related information may be the same, so that only DMRS antenna ports may be randomly determined. In this case, as an example, the DMRS antenna port may be randomly determined based on a UE unique number or a Cyclic Redundancy Checking (CRC) value. As another example, the DMRS antenna port may fixedly use a specific port. For example, the specific port may be port 0.

In addition, as an example, the information configuration method may be preset in consideration of the case where one or two maximum symbols and one or two DMRS configuration types are set.

In this case, as an example, as described above, in the case of group driving, the leader terminal and the non-reader terminal may have the same maximum symbol value and DMRS configuration type.

In this case, whether the maximum symbol is one or two, and whether the DMRS configuration type is 1 or 2 may be preset according to the number of all terminals during group driving. More specifically, when the maximum symbol is one, and the DMRS configuration type is 1, up to four terminals can be distinguished. In addition, when there are two maximum symbols and the DMRS configuration type is 1, up to eight terminals can be distinguished. In addition, when the maximum symbol is one and the DMRS configuration type is 2, up to six terminals may be distinguished. In addition, when there are two maximum symbols and the DMRS configuration type is 2, up to 12 terminals can be distinguished.

Accordingly, the maximum symbol value and the DMRS configuration type may be determined according to a preset method in consideration of the number of terminals included in the cluster.

As another example, the maximum symbol value and the DMRS configuration type may be preset based on the speed of the group driving.

As an example, when the speed of the cluster is greater than or equal to a certain speed, two maximum symbols may be determined. In this case, the constant speed may be a critical speed and may have a constant error.

Based on the above description, the UE operating in mode 4 may determine the maximum symbol value and the DMRS configuration type. Thereafter, the terminal may transmit the information on Tables 27 to 30 described above to another terminal through the SCI. That is, the transmitting terminal may inform the receiving terminal of the DMRS related information used by the transmitting terminal through SCI, and may perform sidelink communication based on the information. For example, during clustering, the transmitting terminal may be a reader terminal, and the receiving terminal may be a nonreader terminal.

In addition, as an example, as described above, there is a need to confirm the DMRS used by the receiving terminal. In this case, in the case of group driving, the case where the leader terminal is the transmitting terminal and the non-reader terminal is the receiving terminal may be considered.

At this time, the receiving terminal receiving the DMRS and data from the transmitting terminal may also transmit the DMRS and data. Therefore, it is necessary to indicate not only the DMRS related information used by the transmitting terminal but also the DMRS related information used by the receiving terminal. For example, DMRS-related information used by the receiving terminal may be configured based on the information of Tables 27 to 30 described above. That is, two pairs of information may be configured based on DMRS-related information of the transmitting terminal and DMRS-related information of the receiving terminal based on the aforementioned Tables 27 to 30.

In addition, as an example, the DMRS related information used by the receiving terminal may be the same as other information, and may indicate only a DMRS antenna port. In this case, within the cluster driving, only the DMRS antenna port may be indicated according to the terminal unique number in the cluster. For example, the terminal unique number may be pre-configured to different values in advance for the terminals in the group driving.

Accordingly, in case of the maximum symbol 1 and the DMRS configuration type 1, the DMRS antenna port used by the transmitting terminal is indicated after indicating a constant value (eg +1, +2, +3) added to the DMRS antenna port used by the transmitting terminal. After adding the values, the receiver terminal may check the DMRS antenna port by performing a modular operation (eg using modular 4).

In addition, as an example, when the maximum symbol is 2 and DMRS configuration type 1, a predetermined value (eg +1, +2, +3, ..., +7) is added to the DMRS antenna port used by the transmitting terminal. After that, the DMRS antenna port used by the transmitting terminal adds the above-described values, and then performs a modular operation so that the receiving terminal can identify the DMRS antenna port. (e.g. using modular 8)

In addition, as an example, when the maximum symbol is 1 and DMRS configuration type 2, after indicating a constant value (eg +1, +2, +3, +4, +5) added to the DMRS antenna port used by the transmitting terminal, The DMRS antenna port used by the transmitting terminal adds the above-described values and then performs a modular operation so that the receiving terminal can identify the DMRS antenna port. (e.g. using modular 6)

In addition, as an example, when the maximum symbol is 2 and the DMRS configuration type 2, a predetermined value (eg +1, +2, +3, ..., +11) is added to the DMRS antenna port used by the transmitting terminal. After that, the DMRS antenna port used by the transmitting terminal adds the above-described values, and then performs a modular operation so that the receiving terminal can identify the DMRS antenna port. (e.g. using modular 12)

In one example, the terminal unique number may be a terminal unique value based on Radio Network Temporary Identities (RNTI), or may be a terminal unique value defined only in a V2X cluster, but is not limited thereto. For example, a terminal unique value such as a Cyclic Redundancy Checking (CRC) value may be used instead of the terminal unique number.

In this case, as an example, each V2X cluster may be composed of a plurality of vehicle terminals that travel with the same direction / speed in the same lane. The two nearest terminals in one cluster have a fixed distance and other terminals cannot be located between them. In this case, the V2X cluster may be a group of V2X terminals composed of one leader terminal and a plurality of non-leader terminals along the leader terminal in cluster driving.

The unique number for each V2X cluster may be indicated by higher level signaling such as RRC or calculated based on the terminal unique number of the reader terminal. The terminal unique value defined only in one V2X cluster is indicated by higher level signaling such as RRC, or after adding a unique number for the V2X cluster to the terminal unique value such as RNTI or CRC, and then a V2X cluster. It may be calculated by performing a modular operation on the number of all terminals belonging to.

Meanwhile, as an example, Example 3-1 and Example 3-2 may be embodiments associated with each other. That is, the terminal may operate based on the above-described embodiments 3-1 and 3-2 based on the set mode and may be embodiments related to each other.

Example 4 (Signaling for Example 1, 2 and / or 3 Selection)

The information structure for the above-described first embodiment, second embodiment, and third embodiment may be selectively determined. For example, the terminal may receive signaling from the base station on whether to configure DMRS related dynamic information based on any one of the method of Embodiment 1, Embodiment 2 and / or Embodiment 3. For example, the base station may instruct the terminal to the above information through the RRC.

In this case, as an example, a selectable method may be selected as one of the first and second embodiments. Also, as an example, one of the two may be selected as the first embodiment and the third embodiment. Also, as an example, any one of the two may be selected as the second embodiment and the third embodiment. In addition, as an example, any one of three may be selected as the first, second and third embodiments, and is not limited to the above-described embodiment.

For example, the DMRS related information configuration may be set based on at least one of the above-described embodiments in consideration of the overhead of the terminal and the interference environment of the surroundings, and is not limited to the above-described embodiment. In addition, as an example, the above-described embodiments may be related embodiments or embodiments as respective independent methods, and are not limited to the above-described embodiments.

8 illustrates a method of performing communication based on sidelinks according to the present invention.

Referring to FIG. 8, the terminal may acquire semi-static DMRS related information. In this case, the semi-static DMRS-related information may be DMRS configuration type information and / or the maximum symbol number information (S810). That is, as described above with reference to FIGS. 1 to 7, the semi-static DMRS-related information is the maximum number of symbols. Information and DMRS configuration type information. In this case, for example, in the base station scheduling mode, the terminal may obtain the above-mentioned semi-static DMRS-related information from the base station through the RRC. That is, the terminal may determine whether the maximum number of symbols is one or two and whether the DMRS configuration type is 1 or 2.

In addition, as an example, in the UE autonomous determination mode, the UE may directly determine the above-mentioned semi-static DMRS related information, as described above.

Next, the UE may acquire at least one or more of symbol number information, DMRS antenna port information, and co-scheduled CDM group information used as dynamic DMRS-related information (S820). As described above, the dynamic DMRS related information may include at least one or more of available symbol number information, CDM group information, and DMRS antenna port information based on the maximum number of symbols, as described above. In this case, for example, in the base station scheduling mode, the terminal may receive dynamic DMRS related information from the base station through the DCI. In this case, the method of configuring the dynamic DMRS related information may be determined based on the first to third embodiments. On the other hand, the DMRS used in the sidelink for V2X, the terminal can consider only "Rank 1 transmission", without considering the TX diversity. Therefore, when configuring a table (e.g. Tables 18 to 29) for the dynamic DMRS-related information, it can be seen that one of the DMRS antenna port of the plurality of DMRS antenna ports is used, as described above. Meanwhile, in the UE autonomous determination mode, the UE may directly determine and obtain dynamic DMRS related information, as described above.

Next, the terminal may transmit the SCI including the dynamic DMRS related information to the other terminal (S830). Then, the terminal may transmit the DMRS and data through the sidelink to the other terminal (S840). As described above with reference to FIGS. 1 to 7, the terminal may acquire dynamic DMRS related information and then transmit the same to another terminal through SCI. In this case, as an example, the terminal may be a transmitting terminal, and the dynamic DMRS related information may be DMRS related information used by the transmitting terminal. In this case, as an example, the SCI may further include DMRS related information used by the receiver, as described above. Through this, the terminal may perform communication with another terminal through a side link.

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

The base station apparatus 900 may include a processor 910, an antenna unit 920, a transceiver 930, and a memory 940.

The processor 910 performs baseband related signal processing and may include an upper layer processor 911 and a physical layer processor 912. The upper layer processor 911 may process operations of a medium access control (MAC) layer, a radio resource control (RRC) layer, or more upper layers. The physical layer processor 912 may process operations (eg, uplink reception signal processing, downlink transmission signal processing, sidelink transmission signal processing, and sidelink reception signal processing) of a physical (PHY) layer. . In addition to performing baseband-related signal processing, the processor 910 may control the overall operation of the base station apparatus 900.

The antenna unit 920 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 930 may include a radio frequency (RF) transmitter and an RF receiver. The memory 940 may store arithmetic processed information of the processor 910, software related to the operation of the base station apparatus 900, an operating system, an application, and the like, and may include components such as a buffer.

Processor 910 of base station 900 may be configured to implement the operation of the base station in the embodiments described herein.

The terminal device 950 may include a processor 960, an antenna unit 970, a transceiver 980, and a memory 990.

The processor 960 performs baseband related signal processing and may include an upper layer processor 961 and a physical layer processor 962. The upper layer processor 961 may process operations of the MAC layer, the RRC layer, or more upper layers. The physical layer processor 962 may process an operation of the PHY layer (for example, downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, and sidelink reception signal processing). In addition to performing baseband related signal processing, the processor 960 may control the overall operation of the terminal device 950.

The antenna unit 970 may include one or more physical antennas, and may support MIMO transmission / reception if the antenna unit 970 includes a plurality of antennas. The transceiver 980 may include an RF transmitter and an RF receiver. The memory 990 may store computationally processed information of the processor 960, software related to the operation of the terminal device 950, an operating system, an application, and the like, and may include components such as a buffer.

The processor 960 of the terminal device 950 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 900 and the terminal apparatus 950, the details described in the examples of the present invention 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 other additional 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.

It is intended that the scope of the disclosure include software or machine-executable instructions (eg, an operating system, an application, firmware, a program, etc.) and actions such that an operation in accordance with the methods of various embodiments is executed on an apparatus or a computer. Instructions, and the like, including non-transitory computer-readable media that are stored and executable on a device or computer.

Base station: 1400 processor: 1410
Upper layer processing unit: 1411 Physical layer processing unit: 1412
Antenna part: 1420 Transceiver: 1430
Memory: 1440 Terminals: 1450
Processor: 1460 Upper Tier Processor: 1461
Physical layer processing unit: 1462 Antenna unit: 1470
Transceiver: 1480 Memory: 1490

Claims (1)

In the method in which the first terminal communicates with the second terminal through the sidelink,
Obtaining semi-static Demodulation Reference Signal (DMRS) related information;
Obtaining dynamic DMRS related information;
Transmitting side link control information (SCI) including the dynamic DMRS related information to the second terminal based on the obtained dynamic DMRS related information; And
And transmitting DMRS and data to the second terminal through the sidelink based on the SCI.
The dynamic DMRS related information is set based on at least one of symbol number information, CDM (Code Division Multiplexing) group information, and DMRS antenna port information available in the maximum symbol.
The DMRS antenna port information is determined based on the case where the first terminal performs only Rank 1 transmission.
The dynamic DMRS related information includes DMRS related information transmitted by the first terminal and DMRS related information transmitted by the second terminal.

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