KR102401977B1 - Method and apparatus for configuring dm-rs for v2x - Google Patents

Abstract

The present invention discloses a DM-RS configuration method and apparatus for V2X. Demodulation for V2X communication according to an aspect of the present invention - A method of transmitting a reference signal (DM-RS) is the same or a different group for one or more units of a subframe, a slot or a symbol to which the DM-RS is mapped determining a hopping value; A first configuration for a case where the number of symbols to which the DM-RS is mapped in one subframe is two, and a second configuration for a case where the number of symbols to which the DM-RS is mapped in one subframe is more than two 2 based on the configuration, determining an orthogonal cover code (OCC) and a cyclic shift value to be applied to the DM-RS; generating the DM-RS sequence based on the determined group hopping value, the OCC, and the cyclic shift value; It may include the step of mapping and transmitting the generated DM-RS sequence to the resource for the V2X communication.

Description

DM-RS configuration method and device for V2X {METHOD AND APPARATUS FOR CONFIGURING DM-RS FOR V2X}

The present invention relates to a wireless communication system, and more specifically, to a DM-RS configuration method and apparatus for V2X.

V2X (Vehicle-to-X; Vehicle-to-Everything) communication refers to a communication method that exchanges or shares information such as traffic conditions while communicating with road infrastructure and other vehicles while driving. V2X is V2V (vehicle-to-vehicle) meaning communication between vehicles, V2P (vehicle-to-pedestrian) meaning communication between a vehicle and a terminal carried by an individual, and a vehicle and roadside unit (RSU). )/V2I/N (vehicle-to-infrastructure/network), which means communication between networks, may be included. In this case, the roadside unit (RSU) may be a transport infrastructure entity implemented by a base station or a fixed terminal. For example, it may be an entity that sends a speed notification to a vehicle.

V2X communication may be implemented according to a device-to-device (D2D) communication method. For example, transmission/reception of control information such as scheduling assignment (SA) is required for V2X communication, and data may be transmitted/received based on such control information. In addition, it is discussed to use a demodulation reference signal (DM-RS) so that a side receiving the SA and/or data can correctly estimate the channel and demodulate the SA and/or data based on the estimated channel. is in progress However, a method for generating a DM-RS sequence that minimizes interference between adjacent UEs while preventing an increase in DM-RS overhead in a subframe has not yet been determined.

The present invention makes it a technical task to provide a DM-RS configuration method and apparatus in V2X communication.

An object of the present invention is to provide a method and apparatus for generating a DM-RS sequence based on group hopping, cyclic shift application, orthogonal cover code application, etc. that minimize interference between adjacent terminals in V2X communication.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. will be able

Demodulation for V2X communication according to an aspect of the present invention - A method of transmitting a reference signal (DM-RS) is the same or a different group for one or more units of a subframe, a slot or a symbol to which the DM-RS is mapped determining a hopping value; A first configuration for a case where the number of symbols to which the DM-RS is mapped in one subframe is two, and a second configuration for a case where the number of symbols to which the DM-RS is mapped in one subframe is more than two 2 based on the configuration, determining an orthogonal cover code (OCC) and a cyclic shift value to be applied to the DM-RS; generating the DM-RS sequence based on the determined group hopping value, the OCC, and the cyclic shift value; It may include the step of mapping and transmitting the generated DM-RS sequence to the resource for the V2X communication.

The features briefly summarized above with respect to the invention are merely exemplary aspects of the detailed description of the invention that follows, and do not limit the scope of the invention.

According to the present invention, a DM-RS configuration method and apparatus in V2X communication may be provided.

According to the present invention, a method and apparatus for generating a DM-RS sequence based on group hopping, cyclic shift application, orthogonal cover codeo mapping, etc. that minimize interference between adjacent terminals in V2X communication may be provided.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are intended to provide an understanding of the present invention, and represent various embodiments of the present invention, and together with the description of the specification, serve to explain the principles of the present invention.
1, 2 and 3 are diagrams for explaining a V2X scenario related to the present invention.
4 shows an example of a UL DM-RS in an uplink (UL) channel and a DM-RS in a SL (sidelink) channel for D2D (or Prose).
5 shows an example of a DM-RS in a channel for PC5 link-based V2X according to D2D (or Prose) of the present invention.
6 is a block diagram illustrating a wireless communication system in which an embodiment of the present invention is implemented.

Hereinafter, in the present specification, the content related to the present invention will be described in detail with reference to exemplary drawings and embodiments together with the content of the present invention. In adding reference numerals to components in each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the embodiments of the present specification, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present specification, the detailed description thereof will be omitted.

In addition, this specification describes a wireless communication network, and the work performed in the wireless communication network is performed in the process of controlling the network and transmitting data in a system (eg, a base station) having jurisdiction over the wireless communication network, or the corresponding wireless communication network. The operation may be performed in a terminal connected to the network.

That is, it is obvious that various operations performed for communication with the terminal in a network including a plurality of network nodes including the base station may be performed by the base station or other network nodes other than the base station. A 'base station (BS: Base Station)' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), and an access point (AP). In addition, 'terminal' may be replaced by terms such as User Equipment (UE), Mobile Station (MS), Mobile Subscriber Station (MSS), Subscriber Station (SS), and non-AP station. can

The terms mainly used as abbreviations used in the present invention are defined as follows.

D2D: Device to Device (communication)

ProSe: (Device to Device) Proximity Services

SL: Sidelink

SCI: Sidelink Control Information

PSSCH: Physical Sidelink Shared Channel

PSBCH: Physical Sidelink Broadcast Channel

PSCCH: Physical Sidelink Control Channel

PSDCH: Physical Sidelink Discovery Channel

SLSS: Sidelink Synchronization Signal (= D2DSS (D2D Synchronization Signal))

SA: Scheduling assignment

DM-RS: DeModulation Reference Signal

PSSID: Physical-layer Sidelink Synchronization Identity

n ^SA _ID : Sidelink group destination identity

n ^SL _ID : Physical layer sidelink synchronization identity

PUSCH: Physical Uplink Shared Channel

In addition, various operation modes may be defined according to a resource allocation method for a direct link (eg, D2D, ProSe, or SL communication). When data and control information for a direct link (eg, D2D, ProSe, or SL communication) are referred to as direct data and direct control information, respectively, Mode 1 is a method in which the terminal directly transmits data and direct control information. It means an operation mode in which the base station (or repeater) schedules the resources used for this purpose accurately, and in mode 2, the terminal selects a resource by itself from the resource pool in order for the terminal to directly transmit data and direct control information. means the mode of operation.

Hereinafter, embodiments of the present invention will be described using V2X communication as an example, but the scope of the present invention is not limited to V2X communication, and embodiments of the present invention are applied to direct link-based communication such as D2D, ProSe, SL communication. can

V2X is a term that collectively refers to V2V, V2P, and V2I/N, and each of V2V, V2P and V2I/N may be defined as shown in Table 1 below in connection with LTE communication.

V2V - covering LTE-based communication between vehicles V2P - covering LTE-based communication between a vehicle and a device carried by an individual (e.g. handheld terminal carried by a pedestrian, cyclist, driver or passenger) V2I/N - covering LTE-based communication between a vehicle and a roadside unit/network
- A roadside unit (RSU) is a stationary infrastructure entity supporting V2X applications that can exchange messages with other entities supporting V2X applications.
- Note: RSU is a term frequently used in existing ITS specifications, and the reason for introducing the term in the 3GPP specifications is to make the documents easier to read for the ITS industry. RSU is a logical entity that combines V2X application logic with the functionality of an eNB (referred to as eNB-type RSU) or UE (referred to as UE-type RSU).

For PC5-based V2V operation, which is a D2D communication link (ie, a direct interface between two devices supporting ProSe) among V2X, Table 2, Table 3, Table 4 below with reference to FIGS. 1, 2 and 3 Various scenarios are being considered.

1, 2 and 3 are diagrams for explaining a V2X scenario related to the present invention.

Table 2 and Figure 1 show scenarios that support V2X operation based only on the PC5 interface. 1 (a) shows a V2V operation, (b) shows a V2I operation, and (c) shows a V2P operation.

- This scenario supports V2X operation only based on PC5.
- In this scenario, a UE transmits a V2X message to multiple UEs at a local area in sidelink.
- For V2I, either transmitter UE or receiver UE(s) are UE-type RSU.
- For V2P, either transmitter UE or receiver UE(s) are pedestrian UE.

Table 3 and Figure 2 show scenarios that support V2X operation based only on the Uu interface (ie, the interface between the UE and the eNB). (a) of FIG. 2 shows a V2V operation, (b) a V2I operation, and (c) a V2P operation.

- This scenario supports V2X operation only based on Uu.
- In this scenario,
For V2V and V2P, a UE transmits a V2X message to E-UTRAN in uplink and E-UTRAN transmits it to multiple UEs at a local area in downlink.
For V2I, when receiver is eNB type RSU, a UE transmits a V2I message to E-UTRAN(eNB type RSU) in uplink; when transmitter is eNB type RSU, E-UTRAN (eNB type RSU) transmits a I2V message to multiple UEs at a local area in downlink.
- For V2P, either transmitter UE or receiver UE(s) are pedestrian UE.
- To support this scenario, E-UTRAN performs uplink reception and downlink transmission of V2X messages. For downlink, E-UTRAN may use a broadcast mechanism.

Table 4 and Figure 3 show scenarios supporting V2X operation using both the Uu interface and the PC5 interface. 3A shows scenario 3A of Table 4, and (b) shows scenario 3B of Table 4.

- This scenario supports V2V operation using both Uu and PC5. Scenario
3A - In this scenario, a UE transmits a V2X message to other UEs in sidelink. One of the receiving UEs is a UE type RSU which receives the V2X message in sidelink and transmits it to E-UTRAN in uplink. E-UTRAN receives the V2X message from the UE type RSU and then transmits it to multiple UEs at a local area in downlink.
- To support this scenario, E-UTRAN performs uplink reception and downlink transmission of V2X messages. For downlink, E-UTRAN may use a broadcast mechanism. Scenario
3B - In this scenario, a UE transmits a V2X message to E-UTRAN in uplink and E-UTRAN transmits it to one or more UE type RSUs. Then, the UE type RSU transmits the V2X message to other UEs in sidelink.
- To support this scenario, E-UTRAN performs uplink reception and downlink transmission of V2X messages. For downlink, E-UTRAN may use a broadcast mechanism.

Hereinafter, UL DM-RS for uplink (UL) PUSCH will be described.

Basics related to UL DM-RS in UL PUSCH are defined as shown in Table 5 below.

Hereinafter, a DM-RS for SL PSSCH/PSCCH/PSDCH/PSBCH (hereinafter, SL DM-RS) will be described.

The basics related to SL DM-RS for D2D (or Prose) are as follows. Unlike the UL DM-RS for the UL PUSCH described in relation to Table 5, in the SL DM-RS, definitions and application formulas of specific parameters are different as shown in Tables 6 and 7 below.

Hereinafter, embodiments of the present invention will be described in detail.

In the case of UL DM-RS in UL PUSCH and DM-RS in SL (sidelink) PSSCH/PSCCH/PSDCH/PSBCH for LTE-based D2D (Prose), one symbol for each slot as shown in FIG. A DM-RS sequence is mapped and a DM-RS is generated and transmitted. That is, one subframe includes two slots (that is, an even index slot (ie, even slot) and an odd index slot (ie, odd slot)), and one slot corresponds to a cyclic prefix (CP) length. Therefore, it may include 6 or 7 symbols. For example, in the case of a normal CP, 7 symbols (ie, symbol indices #0, #1, ..., #6) are included in one slot, and among them, the fourth symbol (ie, DM-RS may be mapped to symbol index #3). In the case of the extended CP (extended CP), 6 symbols (ie, symbol indexes #0, #1, ..., #5) are included in one slot, and among them, the third symbol (ie, symbol index # DM-RS may be mapped to 2).

However, in the case of V2X, in consideration of the high Doppler effect, etc., as shown in FIG. 5 , DM-RS may be mapped and transmitted using more symbols than the example of FIG. 4 in one subframe.

In the case of (a) of FIG. 5 , in the normal CP, the DM-RS is transmitted to the 4th symbol (#3 symbol) and the 6th symbol (#5 symbol) of each slot, but this is only one example and one Two arbitrarily selected symbols among a total of 7 symbols in the slot of may be determined as symbols for transmitting the DM-RS. For example, one of the two symbols in which the DM-RS in each slot is transmitted is the 4th symbol (#3 symbol) of each slot, and the other is the 1st symbol (#0 symbol) and the 2nd symbol of each slot. (symbol #1), symbol 3 (symbol #2), symbol 5 (symbol #4), symbol 6 (symbol #5), and symbol 7 (symbol #6).

Similarly, in the case of (a) of FIG. 5, in the extended CP, the DM-RS is transmitted in the 3rd symbol (#2 symbol) and the 5th symbol (#4 symbol) of each slot, but this is only an example. and 2 arbitrarily selected symbols among a total of 6 symbols in one slot may be determined as symbols for transmitting the DM-RS. For example, one of the two symbols in which the DM-RS is transmitted in each slot is the third symbol (#2 symbol) of each slot, and the other is the first symbol (#0 symbol) and the second symbol of each slot. (symbol #1), symbol 4 (symbol #3), symbol 5 (symbol #4), and symbol 6 (symbol #5).

In the case of (b) of FIG. 5 , in the normal CP, in the first slot and in the second slot, two symbols among the seven symbols in the slot may be determined as symbols for transmitting the DM-RS. For example, as shown as an example in (b) of FIG. 5 , two symbols through which DM-RS is transmitted among the 7 symbols in the first slot are the 3rd symbol (#2 symbol) and the 6th symbol (#5 symbol). ), and two symbols through which DM-RS is transmitted among the 7 symbols in the second slot may be the second symbol (symbol #1) and the fifth symbol (symbol #4).

Similarly, in the case of (b) of FIG. 5, in the extended CP, in the first slot and in the second slot, two symbols among the six symbols in the slot may be determined as symbols for transmitting the DM-RS. For example, as shown as an example in FIG. 5B , two symbols through which DM-RS is transmitted among six symbols in the first slot are the second symbol (#1 symbol) and the fifth symbol (#4 symbol). ), and two symbols through which DM-RS is transmitted among the six symbols in the second slot may be the second symbol (the #1 symbol) and the fifth symbol (the #4 symbol).

In the case of (c) of FIG. 5, in normal CP, in one subframe including the first slot and the second slot, 3 symbols among 14 symbols in the subframe may be determined as symbols for transmitting the DM-RS. . For example, as shown as an example in FIG. 5(c), 3 symbols in which DM-RS is transmitted among 14 symbols in one subframe are the 4th symbol (#3 symbol) and the 7th symbol in the first slot. It could be a symbol (symbol #6) and a fourth symbol in the second slot (symbol #3).

Similarly, in the case of (c) of FIG. 5, in the extended CP, in one subframe including the first slot and the second slot, 3 symbols among 12 symbols in the subframe may be determined as symbols for transmitting the DM-RS. There will be. For example, as shown as an example in FIG. 5( c ), 3 symbols in which DM-RS is transmitted among 12 symbols in one subframe are the 4th symbol (#3 symbol) and the 6th symbol in the first slot. It could be the symbol (#5 symbol) and the second symbol in the second slot (symbol #1).

In this case, in order to minimize interference from neighboring terminals, a more efficient group hopping method, a cyclic shift method, an Orthogonal Cover Code (OCC) or an orthogonal sequence ( Orthogonal sequence), it is necessary to consider the mapping method, etc.

Hereinafter, group hopping for the present invention will be described.

In the case of D2D (Prose), group hopping is applied to each slot during DM-RS transmission associated with PSSCH and PSCCH as shown in Equation 1 below.

로 초기화된다. 여기서 n^RS _ID는 물리 셀 아이디(physical cell ID, PCID)인 N^cell _ID 또는 RRC 등 상위단 시그널링으로부터 지시되는 파라미터인 n^PUCCH _ID 또는 n ^PUSCH _ID 일 수가 있다.In Equation 1, n _s represents a slot index. In addition, c(i) is a pseudo-random sequence defined as a Gold sequence having a length of order 31, and the pseudo-random sequence generator for the pseudo-random sequence is generated every radio frame. At the beginning of (radio frame)

is initialized to Here, n ^RS _ID is an N ^cell _ID that is a physical cell ID (PCID). Alternatively, it may be n ^PUCCH _ID or n ^PUSCH _ID , which is a parameter indicated by upper-stage signaling such as RRC.

Group hopping of Equation 1 is appropriate when DM-RS transmission is performed for one symbol in each slot. However, considering that DM-RS transmission can be made for a plurality of symbols in each slot in V2X, a more efficient group hopping method is required, and the present invention proposes the following method.

Hereinafter, method 1 for a new group hopping according to the present invention will be defined.

According to method 1, as shown in Equation 2 below, considering that DM-RSs are generated in two symbols in one slot, which is the case illustrated in FIG. 5(a) or FIG. 5(b), Two different group hopping patterns are defined in each slot regardless of the positions of the two symbols. The first group hopping pattern is applied to the first symbol in which a DM-RS in one slot is transmitted, and the other group hopping pattern is applied to the second symbol in which a DM-RS in one slot is transmitted. In this case, l'=0 or 1.

로 초기화된다. 이 때, n^PSSCH _ss는 사이드링크를 위한 서브프레임 풀(subframe pool)에서 현재 슬롯의 넘버를 의미한다. 여기서 n^SA _ID 는 사이드링크 그룹 데스티네이션 아이디(sidelink group destination identity) 일 수가 있다.Here, c(i) is a pseudo-random sequence defined as a Gold sequence having a length of order 31, and the pseudo-random sequence generator for the pseudo-random sequence satisfies n ^PSSCH _ss = 0 at the beginning of each slot to

is initialized to In this case, n ^PSSCH _ss means the number of a current slot in a subframe pool for sidelink. Here, n ^SA _ID may be a sidelink group destination identity.

Hereinafter, method 2 for new group hopping according to the present invention will be defined.

According to method 2, as shown in Equation 3 below, considering that DM-RSs are generated in three symbols in one subframe, which is the case exemplified in (c) of FIG. Regardless, three different group hopping patterns are defined in each subframe. The first group hopping pattern is applied to the first symbol in which DM-RS in one subframe is transmitted, the second group hopping pattern is applied to the second symbol in which DM-RS in one subframe is transmitted, and the last three The th group hopping pattern is applied to the third symbol in which the DM-RS in one subframe is transmitted. In this case, l'=0, 1, or 2.

또는

로 초기화된다. 여기서 N^SL _ID 는 물리 레이어 사이드링크 동기화 아이디(physical layer sidelink synchronization identity) 일 수가 있다.Here, c(i) is a pseudo-random sequence defined as a Gold sequence having a length of order 31, and the pseudo-random sequence generator for the pseudo-random sequence generates every PSBCH subframe (PSBCH). at the beginning of the transmitted subframe)

or

is initialized to Here, N ^SL _ID may be a physical layer sidelink synchronization identity.

Hereinafter, method 3 for new group hopping according to the present invention will be defined.

Method 3, as shown in Equation 4 below, defines a different group hopping pattern for each symbol in one slot for each symbol, and defines each symbol in the corresponding symbol in which the DM-RS is transmitted. This is a method to apply the group hopping pattern to . This is applicable to all cases exemplified through FIGS. 5(a), 5(b) and 5(c). In this case, N ^SL _symb is the number of symbols in one slot in the SL (sidelink) (7 in the case of a normal CP, 6 in the case of an extended CP), and l=0,1,..., N ^SL _symb is a symbol index within one slot.

In Equation 4, n _s is n ^PSSCH _ss when the above equation is applied in DM-RS for PSSCH.

Meanwhile, in Equation 4, n _s has two values: 0 or 1 when the above Equation is applied in DM-RS for PSBCH.

Also, c(i) is a pseudo-random sequence defined as a Gold sequence having a length of order 31.

초기화 된다.When Equation 4 is applied in the _DM -RS for the ^PSSCH , the pseudo-random sequence generator for the pseudo-random sequence is

is initialized.

또는

로 초기화된다. On the other hand, when Equation 4 is applied in DM-RS for PSBCH, the pseudo-random sequence generator for the pseudo-random sequence is performed at the beginning of every PSBCH subframe (a subframe transmitting PSBCH).

or

is initialized to

At this time, n ^PSSCH _ss denotes the number of the current slot in the subframe pool for the sidelink. where n ^SA _ID is a sidelink group destination identity (sidelink group destination identity), N ^SL _ID may be a physical layer sidelink synchronization identity (physical layer sidelink synchronization identity).

In method 1 and method 2 for new group hopping according to the present invention for V2X, group hopping is defined in consideration of only symbols to which DM-RS is mapped, as in LTE PUSCH-based D2D (Prose).

Method 3 for new group hopping according to the present invention for V2X is a method in which group hopping is applied to each symbol, and a predefined group hopping is applied to each symbol in a symbol to which DM-RS is mapped.

가 같은 경우) 동일한 심볼에서 서로 동시에 전송 될 수 있는 D2D(Prose)에서의 DM-RS와 V2X에서의 DM-RS 사이에서의 간섭을 최소화 시켜줄 수 있는 장점이 있다. 예를 들어, 도 4를 통해 예시한 LTE PUSCH 기반의 D2D(Prose)에서 첫 번째 슬롯의 DM-RS가 매핑되는 하나의 심볼에서는 c(0)~c(7)까지의 의사-랜덤 시퀀스의 값을 토대로 group hopping이 정해진다. 이 때, V2X를 위한 본 발명의 따른 새로운 group hopping을 위한 방법 1 및 방법 2를 따를 경우 역시 첫 번째 슬롯의 DM-RS가 매핑되는 첫 번째 심볼(이 심볼은 상기 LTE PUSCH 기반의 D2D(Prose)에서 첫 번째 슬롯의 DM-RS가 매핑되는 하나의 심볼과 동일한 위치의 심볼일 수도 있음)에서는 c(0)~c(7)까지의 의사-랜덤 시퀀스의 값을 토대로 group hopping이 정해질 수가 있다. 하지만, V2X를 위한 본 발명의 따른 새로운 group hopping을 위한 방법 3을 따를 경우 첫 번째 슬롯의 DM-RS가 매핑되는 첫 번째 심볼(이 심볼은 상기 LTE PUSCH 기반의 D2D(Prose)에서 첫 번째 슬롯의 DM-RS가 매핑되는 하나의 심볼과 동일한 위치의 심볼 수도 있음)에서는 c(8(심볼 넘버)+0)~c(8(심볼 넘버)+7)까지의 의사-랜덤 시퀀스의 값을 토대로 group hopping이 정해질 수 있는 것이다. When method 3 for new group hopping according to the present invention is applied, group hopping in a symbol to which DM-RS is mapped in LTE PUSCH-based D2D (Prose) and a symbol to which DM-RS is mapped in V2X according to the present invention Since group hopping can be set differently, c _init is the same (for example, n ^SA _IDs are different, but

is the same), there is an advantage of minimizing interference between the DM-RS in D2D (Prose) and the DM-RS in V2X, which can be simultaneously transmitted in the same symbol. For example, in one symbol to which the DM-RS of the first slot is mapped in the LTE PUSCH-based D2D (Prose) illustrated in FIG. 4 , the pseudo-random sequence values from c(0) to c(7) Based on this, group hopping is determined. At this time, if method 1 and method 2 for new group hopping according to the present invention for V2X are followed, the first symbol to which the DM-RS of the first slot is also mapped (this symbol is the LTE PUSCH-based D2D (Prose) group hopping can be determined based on the pseudo-random sequence values from c(0) to c(7) in the same position as one symbol to which the DM-RS of the first slot is mapped. . However, when the method 3 for new group hopping according to the present invention for V2X is followed, the first symbol to which the DM-RS of the first slot is mapped (this symbol is the first slot of the LTE PUSCH-based D2D (Prose) Based on the value of the pseudo-random sequence from c (8 (symbol number) + 0) to c (8 (symbol number) + 7) in the same position as one symbol to which DM-RS is mapped), group hopping can be determined.

Hereinafter, an orthogonal sequence (OCC) and cyclic shift according to the present invention will be described.

In order to minimize interference from neighboring terminals, a cyclic shift and an orthogonal sequence (OCC) are considered when generating a DM-RS. In the case of D2D (Prose), a length 2 OCC (Orthogonal Cover Code) is applied as an orthogonal sequence (OCC) in consideration of transmission of DM-RS to two symbols in one subframe. However, in the case of V2X, when considering that DM-RS is transmitted for 4 symbols in one subframe, length 4 OCC (Orthogonal Cover Code) can be considered as an orthogonal sequence (OCC), and thus more efficient between adjacent terminals In order to minimize interference, it is necessary to change the application of the orthogonal sequence (OCC). In addition, it is also necessary to consider the more efficient application of the cyclic shift in response to the change of the application details for the orthogonal sequence (OCC).

Here, when DM-RS is transmitted with respect to four symbols in one subframe, two symbol positions among the positions of four symbols in a subframe are DM-RS transmitted for two symbols in one subframe. It is the same as the position in D2D (Prose) and the additional configuration of the remaining two symbol positions will be more effective in terms of minimizing interference from neighboring terminals.

This means that when a UE transmitting DM-RS in a V2X environment and a UE transmitting DM-RS in a D2D (Prose) environment are mixed, the application of an orthogonal sequence (OCC) when transmitting DM-RS in a V2X environment is applied to D2D (Prose). ), this is because mutual interference can be mitigated through orthogonal sequence (OCC) if extended based on the application of orthogonal sequence (OCC) during DM-RS transmission. For example, when DM-RS transmission in a V2X environment, the orthogonal sequence (OCC) application method in 2 symbols for 4 symbols in one subframe is one of DM-RS transmission in D2D (Prose). If it is the same as the orthogonal sequence (OCC) application method in two symbols within a subframe, interference to each other in these two symbols may be mitigated with each other.

On the other hand, as mentioned above, in the case of V2X, in consideration of a high Doppler effect, etc., it may be preferentially considered that DM-RS is transmitted for 4 symbols in one subframe. However, in the case of PSBCH transmitted together in a subframe such as SLSS (Sidelink Synchronization Signal), it may be considered that DM-RS is transmitted for three symbols in one subframe when considering the symbols for the SLSS. will be. In this case, a length 3 OCC (Orthogonal Cover Code) can be considered as the orthogonal sequence (OCC), and accordingly, the application of the orthogonal sequence (OCC) needs to be changed for more efficient minimization of interference between adjacent terminals. In addition, it is also necessary to consider the more efficient application of the cyclic shift in response to the change of the application details for the orthogonal sequence (OCC).

First, in the case of D2D (Prose), while two OCCs of length 2 are used, two types of OCC are the same, but when the length of OCC is 4 (method 1-1 and method 1 for orthogonal sequence (OCC) and cyclic shift) -2) may be considered for V2X. This may be applicable to the case exemplified in (a) of FIG. 5, but is not limited thereto.

More specifically, it is as follows.

[ Orthogonal sequence ( OCC ) and method 1-1 for cyclic shift ]

In this case, when a normal CP is used, one of two symbols in which a DM-RS in each slot is transmitted is associated with a DM-RS associated with an existing UL PUSCH or a PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose). Same as DM-RS, the 4th symbol (#3 symbol) of each slot, and the other one is the next symbol in the slot (5th symbol (#4 symbol), 6th symbol (#5 symbol), and 7th symbol (#6 symbol)) is one of these cases.

In addition, in this case, when the extended CP is used, one of two symbols in which the DM-RS in each slot is transmitted is the DM-RS associated with the existing UL PUSCH or PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose) and Same as the associated DM-RS, it is the 3rd symbol (#2 symbol) of each slot, and the other one is the next symbol in the slot (the 4th symbol (#3 symbol), the 5th symbol (#4 symbol), and the 6th symbol) symbol (#5 symbol)).

At this time, since the position of two symbols among the four symbols in one subframe is the same and the remaining two symbols are added, in the case of V2X, the existing two symbols in one subframe and the two symbols to be added are always added together. DM-RS may be transmitted through a total of 4 symbols. Alternatively, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through upper-stage signaling such as RRC (configuration #1) and two existing symbols and addition in one subframe It may be configured by selectively selecting one of the configurations (configuration #2) that transmits the DM-RS through a total of 4 symbols by adding the two symbols to be used.

As shown in Table 8, in consideration of DM-RS transmission for a total of 4 symbols in one subframe in DM-RS associated with PSSCH and PSBCH, two types of length 4 OCC [+1 +1 +1 +1] and [+1 -1 -1 +1] can be used.

Considering DM-RS transmission for a total of two symbols in one subframe in DM-RS associated with PSSCH and PSBCH in D2D (Prose), two types of length 2 OCC [+1 +1] and [ +1 -1] can be used, and when this is extended in consideration of DM-RS transmission for a total of 4 symbols in one subframe, [+1 +1 +1 +1] and [+1 -1 +1 -1] can be However, in this case, the OCC configuration as shown in Table 8 is different because the OCC mapping in two symbols (the first symbol and the third symbol among the four symbols) with the same symbol position as in the conventional D2D (Prose) among the four symbols is different. It would be desirable

In relation to other cyclic shifts, the same configuration as that in D2D (Prose) will be possible.

[ Method 1-2 for Orthogonal sequence ( OCC ) and cyclic shift ]

In this case, when a normal CP is used, one of two symbols in which a DM-RS in each slot is transmitted is associated with a DM-RS associated with an existing UL PUSCH or a PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose). Same as DM-RS, the 4th symbol (#3 symbol) of each slot, and the other one is the previous symbols in the slot (1st symbol (#0 symbol), 2nd symbol (#1 symbol), and 3rd symbol) symbol (#2 symbol)).

In addition, in this case, when the extended CP is used, one of two symbols in which the DM-RS in each slot is transmitted is the DM-RS associated with the existing UL PUSCH or PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose) and The third symbol (#2 symbol) of each slot is the same as the associated DM-RS, and the other one is among the previous symbols (the first symbol (#0 symbol) and the second symbol (#1 symbol)) in the slot. In case one is

At this time, since the position of two symbols among the four symbols in one subframe is the same and the remaining two symbols are added, in the case of V2X, the existing two symbols in one subframe and the two symbols to be added are always added together. DM-RS may be transmitted through a total of 4 symbols. Alternatively, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through upper-stage signaling such as RRC (configuration #1) and two existing symbols and addition in one subframe It may be configured by selectively selecting one of the configurations (configuration #2) that transmits the DM-RS through a total of 4 symbols by adding the two symbols to be used.

As shown in Table 9, in consideration of DM-RS transmission for a total of 4 symbols in one subframe in DM-RS associated with PSSCH and PSBCH, two types of length 4 OCC [+1 +1 +1 +1] and [-1 +1 +1 -1] can be used.

Considering DM-RS transmission for a total of two symbols in one subframe in DM-RS associated with PSSCH and PSBCH in D2D (Prose), two types of length 2 OCC [+1 +1] and [ +1 -1] may be used, and when this is extended in consideration of DM-RS transmission for a total of 4 symbols in one subframe, [+1 +1 +1 +1] and [+1 -1 +1 -1] can be However, in this case, the OCC configuration as shown in Table 9 is different because the OCC mapping in two symbols (the second symbol and the fourth symbol among the four symbols) having the same symbol position as in the conventional D2D (Prose) among the four symbols is different. It would be desirable

In relation to other cyclic shifts, the same configuration as that in D2D (Prose) will be possible.

Next, in the case of D2D (Prose), while 2 OCCs of length 2 are used, the number of OCC types is increased to 4, and when the length of OCC is 4 (method 2-1, method 2- for orthogonal sequence (OCC) and cyclic shift) 2, Method 3-1 and Method 3-2) may be considered for V2X. This may be applicable to the case exemplified in (a) of FIG. 5, but is not limited thereto.

[ Orthogonal sequence ( OCC ) and method 2-1 for cyclic shift ]

In this case, when a normal CP is used, one of two symbols in which a DM-RS in each slot is transmitted is associated with a DM-RS associated with an existing UL PUSCH or a PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose). Same as DM-RS, the 4th symbol (#3 symbol) of each slot, and the other one is the next symbol in the slot (5th symbol (#4 symbol), 6th symbol (#5 symbol), and 7th symbol (#6 symbol)) is one of these cases.

In addition, in this case, when the extended CP is used, one of two symbols in which the DM-RS in each slot is transmitted is the DM-RS associated with the existing UL PUSCH or PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose) and Same as the associated DM-RS, it is the 3rd symbol (#2 symbol) of each slot, and the other one is the next symbol in the slot (the 4th symbol (#3 symbol), the 5th symbol (#4 symbol), and the 6th symbol) symbol (#5 symbol)).

At this time, since the position of two symbols among the four symbols in one subframe is the same and the remaining two symbols are added, in the case of V2X, the existing two symbols and the two symbols to be added are always added together in one subframe. DM-RS may be transmitted through a total of 4 symbols. Alternatively, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through higher-end signaling such as RRC (configuration #1) and two existing symbols and addition in one subframe It may be configured by selectively selecting one of the configurations (configuration #2) that transmits the DM-RS through a total of 4 symbols by adding the two symbols to be used.

As shown in Table 10, in consideration of DM-RS transmission for a total of four symbols in one subframe in DM-RS associated with PSSCH and PSBCH, four types of length 4 OCC [+1 +1 +1 +1], [+1 -1 -1 +1], [+1 -1 +1 -1] and [+1 +1 -1 -1] can be used.

Each of the four length 4 OCCs [+1 +1 +1 +1], [+1 -1 -1 +1], [+1 -1 +1 -1] and [+1 +1 -1 -1] In the case of DM-RS linked to PSSCH, n ^SA _ID is divided by 4 and the remainder is 0, 1, 2, and 3, respectively. In the case of DM-RS linked to PSBCH, n ^SL _ID is divided by 4 and the remainder is It is used in the case of 0, 1, 2, and 3 respectively.

This is an OCC configuration capable of maintaining the same OCC mapping in two symbols (the first symbol and the third symbol among the four symbols) having the same symbol position as in the conventional D2D (Prose) among the four symbols. That is, in the case of DM-RS associated with PSSCH, OCC values in the first and third symbols in the case where n ^SA _ID is divided by 2 and the remainder are 0 and 1, respectively, are [+1 +1], [+1 , -1].

In relation to other cyclic shifts, the same configuration as that in D2D (Prose) will be possible. However, since different OCCs are applied to two cyclic shift values having adjacent cyclic shift values, interference between adjacent UEs may be reduced.

[ Orthogonal sequence ( OCC ) and method 2-2 for cyclic shift ]

In this case, when a normal CP is used, one of two symbols in which a DM-RS in each slot is transmitted is associated with a DM-RS associated with an existing UL PUSCH or a PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose). Same as DM-RS, the 4th symbol (#3 symbol) of each slot, and the other one is the previous symbols in the slot (1st symbol (#0 symbol), 2nd symbol (#1 symbol), and 3rd symbol) symbol (#2 symbol)).

In addition, in this case, when the extended CP is used, one of two symbols in which the DM-RS in each slot is transmitted is the DM-RS associated with the existing UL PUSCH or PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose) and The third symbol (#2 symbol) of each slot is the same as the associated DM-RS, and the other one is among the previous symbols (the first symbol (#0 symbol) and the second symbol (#1 symbol)) in the slot. In case one is

At this time, since the position of two symbols among the four symbols in one subframe is the same and the remaining two symbols are added, in the case of V2X, the existing two symbols and the two symbols to be added are always added together in one subframe. DM-RS may be transmitted through a total of 4 symbols. Alternatively, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through higher-end signaling such as RRC (configuration #1) and two existing symbols and addition in one subframe It may be configured by selectively selecting one of the configurations (configuration #2) that transmits the DM-RS through a total of 4 symbols by adding the two symbols to be used.

As shown in Table 11, in consideration of DM-RS transmission for a total of 4 symbols in one subframe in DM-RS associated with PSSCH and PSBCH, [+1 +1 +1 +1], [-1 +1 +1 -1], [-1 +1 -1 +1] and [+1 +1 -1 -1] can be used.

Each of the four length 4 OCCs [+1 +1 +1 +1], [-1 +1 +1 -1], [-1 +1 -1 +1] and [+1 +1 -1 -1] In the case of DM-RS linked to PSSCH, n ^SA _ID is divided by 4 and the remainder is 0, 1, 2, and 3, respectively. In the case of DM-RS linked to PSBCH, n ^SL _ID is divided by 4 and the remainder is It is used for 0, 1, 2, and 3 respectively.

This is an OCC configuration capable of maintaining the same OCC mapping in two symbols (the second symbol and the fourth symbol among the four symbols) having the same symbol position as in the conventional D2D (Prose) among the four symbols. That is, in the case of DM-RS associated with PSSCH, OCC values in the second symbol and the fourth symbol in the case where n ^SA _ID is divided by 2 and the remainder are 0 and 1, respectively, are [+1 +1], [+1 -1]. Also, in the case of DM-RS associated with PSBCH, the OCC values in the second and fourth symbols in the case where n ^SL _IDs are divided by 2 and the remainder are 0 and 1, respectively, are [+1 +1], [+1 -1].

In relation to other cyclic shifts, the same configuration as that in D2D (Prose) will be possible. However, since different OCCs are applied to two cyclic shift values having adjacent cyclic shift values, interference between adjacent UEs may be reduced.

[ Method 3-1 for Orthogonal sequence ( OCC ) and cyclic shift ]

In this case, when a normal CP is used, one of two symbols in which a DM-RS in each slot is transmitted is associated with a DM-RS associated with an existing UL PUSCH or a PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose). Same as DM-RS, the 4th symbol (#3 symbol) of each slot, and the other one is the next symbol in the slot (5th symbol (#4 symbol), 6th symbol (#5 symbol), and 7th symbol (#6 symbol)) is one of these cases.

Also, in this case, when the extended CP is used, one of the two symbols in which the DM-RS in each slot is transmitted is the DM-RS associated with the existing UL PUSCH or the PSSCH/PSCCH/PDSCH/PSBCH in the D2D (Prose) and Same as the associated DM-RS, it is the 3rd symbol (#2 symbol) of each slot, and the other one is the next symbol in the slot (the 4th symbol (#3 symbol), the 5th symbol (#4 symbol), and the 6th symbol) symbol (#5 symbol)).

At this time, since the position of two symbols among the four symbols in one subframe is the same and the remaining two symbols are added, in the case of V2X, the existing two symbols and the two symbols to be added are always added together in one subframe. DM-RS may be transmitted through a total of 4 symbols. Alternatively, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through higher-end signaling such as RRC (configuration #1) and two existing symbols and addition in one subframe It may be configured by selectively selecting one of the configurations (configuration #2) that transmits the DM-RS through a total of 4 symbols by adding the two symbols to be used.

As shown in Table 12, in consideration of DM-RS transmission for a total of 4 symbols in one subframe in DM-RS associated with PSSCH and PSBCH, [+1 +1 +1 +1], [+1 -1 -1 +1], [+1 -1 +1 -1] and [+1 +1 -1 -1] can be used.

Each of the four length 4 OCCs [+1 +1 +1 +1], [+1 -1 -1 +1], [+1 -1 +1 -1] and [+1 +1 -1 -1] In the case of DM-RS linked to PSSCH, n ^SA _ID is divided by 4 and the remainder is 0, 1, 2, and 3, respectively. In the case of DM-RS linked to PSBCH, n ^SL _ID is divided by 4 and the remainder is It is used in the case of 0, 1, 2, and 3 respectively.

This is an OCC configuration capable of maintaining the same OCC mapping in two symbols (the first symbol and the third symbol among the four symbols) having the same symbol position as in the conventional D2D (Prose) among the four symbols. That is, in the case of DM-RS associated with PSSCH, OCC values in the first and third symbols in the case where n ^SA _ID is divided by 2 and the remainder are 0 and 1, respectively, are [+1 +1], [+1 -1].

In relation to other cyclic shifts, in case of DM-RS linked to PSSCH in D2D (Prose), if one of eight cyclic shift values is determined by performing a modular operation 8 on the quotient value obtained by dividing n ^SA _ID by 2 , in the case of DM-RS associated with PSSCH in V2X, one of eight cyclic shift values can be determined by performing a modular operation 8 on a quotient value obtained by dividing n ^SA _ID by 4 . Similarly, in the case of DM-RS linked to PSBCH in D2D (Prose), if one of 8 cyclic shift values is determined by performing a modular operation 8 on the quotient value obtained by dividing n ^SL _ID by 2, the PSBCH and PSBCH in V2X In the case of a linked DM-RS, one of 8 types of cyclic shift values can be determined by performing a modular operation 8 on a quotient value obtained by dividing n ^SL _ID by 4. In addition, in the case of DM-RS linked to PSBCH in D2D (Prose), modular operation 30 is performed on the quotient value obtained by dividing n ^SL _ID by 16, and 30 sequence shift patterns in group hopping (f) _ss ) if one of the values is determined, in the case of DM-RS linked to PSBCH in V2X, modular operation 30 is performed on the quotient value obtained by dividing n ^SL _ID by 32, and 30 sequence shifts in group hopping (sequence shift) ) pattern (f _ss ) value can be determined.

[ Orthogonal sequence ( OCC ) and method for cyclic shift 3-2 ]

In this case, when a normal CP is used, one of two symbols in which a DM-RS in each slot is transmitted is associated with a DM-RS associated with an existing UL PUSCH or a PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose). Same as DM-RS, the 4th symbol (#3 symbol) of each slot, and the other one is the previous symbols in the slot (1st symbol (#0 symbol), 2nd symbol (#1 symbol), and 3rd symbol) symbol (#2 symbol)).

In addition, in this case, when the extended CP is used, one of two symbols in which the DM-RS in each slot is transmitted is the DM-RS associated with the existing UL PUSCH or PSSCH/PSCCH/PDSCH/PSBCH in D2D (Prose) and The third symbol (#2 symbol) of each slot is the same as the associated DM-RS, and the other one is among the previous symbols (the first symbol (#0 symbol) and the second symbol (#1 symbol)) in the slot. In case one is

At this time, since the position of two symbols among the four symbols in one subframe is the same and the remaining two symbols are added, in the case of V2X, the existing two symbols and the two symbols to be added are always added together in one subframe. DM-RS may be transmitted through a total of 4 symbols. Alternatively, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through higher-end signaling such as RRC (configuration #1) and two existing symbols and addition in one subframe It may be configured by selectively selecting one of the configurations (configuration #2) for transmitting the DM-RS through a total of 4 symbols by adding the two symbols to be used.

As shown in Table 13, in consideration of DM-RS transmission for a total of 4 symbols in one subframe in the DM-RS associated with the PSSCH and PSBCH, [+1 +1 +1 +1], [-1 +1 +1 -1], [-1 +1 -1 +1] and [+1 +1 -1 -1] can be used.

The four length 4 OCC [+1 +1 +1 +1], [-1 +1 +1 -1], [-1 +1 -1 +1], [+1 +1 -1 -1], respectively In the case of DM-RS linked to PSSCH, n ^SA _ID is divided by 4 and the remainder is 0, 1, 2, and 3, respectively. In the case of DM-RS linked to PSBCH, n ^SL _ID is divided by 4 and the remainder is It is used in the case of 0, 1, 2, and 3 respectively.

This is an OCC configuration capable of maintaining the same OCC mapping in two symbols (the second symbol and the fourth symbol among the four symbols) having the same symbol position as in the conventional D2D (Prose) among the four symbols. That is, in the case of DM-RS associated with PSSCH, OCC values in the second symbol and the fourth symbol in the case where n ^SA _ID is divided by 2 and the remainder are 0 and 1, respectively, are [+1 +1], [+1 -1].

In relation to other cyclic shifts, in case of DM-RS linked to PSSCH in D2D (Prose), if one of eight cyclic shift values is determined by performing a modular operation 8 on the quotient value of n ^SA _ID by 2 , in the case of DM-RS associated with PSSCH in V2X, one of eight cyclic shift values can be determined by performing a modular operation 8 on a quotient value obtained by dividing n ^SA _ID by 4 . Similarly, in the case of DM-RS linked to PSBCH in D2D (Prose), if one of 8 cyclic shift values is determined by performing a modular operation 8 on the quotient value obtained by dividing n ^SL _ID by 2, the PSBCH and PSBCH in V2X In the case of a linked DM-RS, one of 8 types of cyclic shift values can be determined by performing a modular operation 8 on a quotient value obtained by dividing n ^SL _ID by 4. In addition, in the case of DM-RS linked to PSBCH in D2D (Prose), modular operation 30 is performed on the quotient value obtained by dividing n ^SL _ID by 16, and 30 sequence shift patterns in group hopping (f) _ss ) if one of the values is determined, in the case of DM-RS linked to PSBCH in V2X, modular operation 30 is performed on the quotient value obtained by dividing n ^SL _ID by 32, and 30 sequence shifts in group hopping (sequence shift) ) pattern (f _ss ) value can be determined.

Next, in the case of D2D (Prose), while two OCCs of length 2 are used, the types of OCC are the same as two, but when the length of OCC is 4 (method 4 for orthogonal sequence (OCC) and cyclic shift), V2X may be considered for This may be applicable to the case exemplified in (b) of FIG. 5, but is not limited thereto.

[ Orthogonal sequence ( OCC ) and method 4 for cyclic shift ]

In this case, when a normal CP is used, in the first slot and in the second slot, two symbols out of seven symbols in each slot may be determined as symbols for transmitting the DM-RS.

Also, in this case, when the extended CP is used, in the first slot and in the second slot, two symbols among six symbols in each slot may be determined as symbols for transmitting the DM-RS.

To this end, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through upper-stage signaling such as RRC (configuration #1) and a total of 4 symbols in one subframe It may be configured by selecting one of the configurations (configuration #2) for transmitting the DM-RS through.

As shown in Table 14, in consideration of DM-RS transmission for a total of 4 symbols in one subframe in DM-RS associated with PSSCH and PSBCH, two types of length 4 OCC [+1 +1 +1 +1] and [+1 -1 +1 -1] can be used.

Each of the two length 4 OCCs [+1 +1 +1 +1] and [+1 -1 +1 -1] divides n ^SA _ID by 2 in the case of DM-RS associated with PSSCH, and the remainder is 0, It is used in the case of 1, and in the case of DM-RS associated with PSBCH, n ^SL _ID is divided by 2 and the remainder is 0 and 1, respectively.

In relation to other cyclic shifts, the same configuration as that in D2D (Prose) will be possible.

Next, in the case of D2D (Prose), while 2 OCCs of length 2 are used, the type of OCC is also increased to 4, and when the length of OCC is 4 (method 5 and method 6 for orthogonal sequence (OCC) and cyclic shift), V2X may be considered for This may be applicable to the case exemplified in (b) of FIG. 5, but is not limited thereto.

[ Orthogonal sequence ( OCC ) and method 5 for cyclic shift ]

In this case, when a normal CP is used, in the first slot and in the second slot, two symbols out of seven symbols in each slot may be determined as symbols for transmitting the DM-RS.

Also, in this case, when the extended CP is used, in the first slot and in the second slot, two symbols among six symbols in each slot may be determined as symbols for transmitting the DM-RS.

To this end, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through upper-stage signaling such as RRC (configuration #1) and a total of 4 symbols in one subframe It may be configured by selecting one of the configurations (configuration #2) for transmitting the DM-RS through.

As shown in Table 15, in consideration of DM-RS transmission for a total of 4 symbols in one subframe in DM-RS associated with PSSCH and PSBCH, 4 types of length 4 OCC [+1 +1 +1 +1], [+1 -1 +1 -1], [+1 +1 -1 -1] and [+1 -1 -1 +1] can be used.

Each of the four length 4 OCCs [+1 +1 +1 +1], [+1 -1 +1 -1], [+1 +1 -1 -1] and [+1 -1 -1 +1] In the case of DM-RS linked to PSSCH, n ^SA _ID is divided by 4 and the remainder is 0, 1, 2, and 3, respectively. In the case of DM-RS linked to PSBCH, n ^SL _ID is divided by 4 and the remainder is It is used in the case of 0, 1, 2, and 3 respectively.

In relation to other cyclic shifts, the same configuration as that in D2D (Prose) will be possible. However, since different OCCs are applied to two cyclic shift values having adjacent cyclic shift values, interference between adjacent UEs may be reduced.

[ Orthogonal sequence ( OCC ) and method 6 for cyclic shift ]

In this case, when a normal CP is used, in the first slot and in the second slot, two symbols out of seven symbols in each slot may be determined as symbols for transmitting the DM-RS.

Also, in this case, when the extended CP is used, in the first slot and in the second slot, two symbols among six symbols in each slot may be determined as symbols for transmitting the DM-RS.

To this end, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through upper-stage signaling such as RRC (configuration #1) and a total of 4 symbols in one subframe It may be configured by selecting one of the configurations (configuration #2) for transmitting the DM-RS through.

As shown in Table 16, in consideration of DM-RS transmission for a total of four symbols in one subframe in DM-RS associated with PSSCH and PSBCH, [+1 +1 +1 +1], [+1 -1 +1 -1], [+1 +1 -1 -1] and [+1 -1 -1 +1] can be used.

Each of the four length 4 OCCs [+1 +1 +1 +1], [+1 -1 +1 -1], [+1 +1 -1 -1] and [+1 -1 -1 +1] In the case of DM-RS linked to PSSCH, n ^SA _ID is divided by 4 and the remainder is 0, 1, 2, and 3, respectively. In the case of DM-RS linked to PSBCH, n ^SL _ID is divided by 4 and the remainder is It is used in the case of 0, 1, 2, and 3 respectively.

In relation to other cyclic shifts, in case of DM-RS linked to PSSCH in D2D (Prose), if one of eight cyclic shift values is determined by performing a modular operation 8 on the quotient value obtained by dividing n ^SA _ID by 2 , in the case of DM-RS associated with PSSCH in V2X, one of eight cyclic shift values can be determined by performing a modular operation 8 on a quotient value obtained by dividing n ^SA _ID by 4 . Similarly, in the case of DM-RS linked to PSBCH in D2D (Prose), if one of 8 cyclic shift values is determined by performing a modular operation 8 on the quotient value obtained by dividing n ^SL _ID by 2, the PSBCH and PSBCH in V2X In the case of a linked DM-RS, one of 8 types of cyclic shift values can be determined by performing a modular operation 8 on a quotient value obtained by dividing n ^SL _ID by 4. In addition, in the case of DM-RS linked to PSBCH in D2D (Prose), modular operation 30 is performed on the quotient value obtained by dividing n ^SL _ID by 16, and 30 sequence shift patterns in group hopping (f) _ss ) if one of the values is determined, in the case of DM-RS linked to PSBCH in V2X, modular operation 30 is performed on the quotient value obtained by dividing n ^SL _ID by 32, and 30 sequence shifts in group hopping (sequence shift) ) pattern (f _ss ) value can be determined.

Next, in the case of D2D (Prose), while 2 OCCs of length 2 are used, the type of OCC is the same as 2, but when the length of OCC is 3 (method 7 for orthogonal sequence (OCC) and cyclic shift), V2X may be considered for This may be applicable to the case illustrated in (c) of FIG. 5, but is not limited thereto.

[ Orthogonal sequence ( OCC ) and method 7 for cyclic shift ]

In this case, when a normal CP is used, 3 symbols out of 14 symbols in one subframe can be determined as symbols for transmitting the DM-RS.

Also, in this case, when the extended CP is used, 3 symbols among 12 symbols in one subframe may be determined as symbols for transmitting the DM-RS.

To this end, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through upper-stage signaling such as RRC (configuration #1) and a total of three symbols in one subframe It may be configured by selecting one of the configurations (configuration #2) for transmitting the DM-RS through.

As shown in Table 17, in consideration of DM-RS transmission for a total of three symbols in one subframe in DM-RS associated with PSBCH, two types of length 3 OCC [+1 +1 +1] and [+1 e ^{j2π /3} e ^{j4π / 3} ] can be used. Alternatively, [+1 +1 +1] and [+1 e ^{j4π /3} e ^{j2π / 3} ] may be used as two types of length 3 OCC.

Each of the two length 3 OCC [+1 +1 +1], [+1 e ^{j2π /3} e ^{j4π /3} ] is (or the two length 3 OCC [+1 +1 +1], [+1 e ^{j4π /3} e ^{j2π /3} ] each) In case of DM-RS linked to PSBCH, n ^SL _ID is divided by 2 and the remainder is 0 and 1, respectively.

In relation to other cyclic shifts, the same configuration as that in D2D (Prose) will be possible.

Next, in the case of D2D (Prose), while 2 OCCs of length 2 are used, the type of OCC is also increased to 3, and when the length of OCC is 3 (method 8 and method 9 for orthogonal sequence (OCC) and cyclic shift), V2X may be considered for This may be applicable to the case exemplified in (c) of FIG. 5, but is not limited thereto.

[ Orthogonal sequence ( OCC ) and method 8 for cyclic shift ]

In this case, when a normal CP is used, 3 symbols out of 14 symbols in one subframe can be determined as symbols for transmitting the DM-RS.

Also, in this case, when the extended CP is used, 3 symbols among 12 symbols in one subframe may be determined as symbols for transmitting the DM-RS.

For this, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through upper-stage signaling such as RRC (configuration #1) and a total of three symbols in one subframe It may be configured by selecting one of the configurations (configuration #2) for transmitting the DM-RS through.

As shown in Table 18, in consideration of DM-RS transmission for a total of three symbols in one subframe in DM-RS associated with PSBCH, three types of length 3 OCC [+1 +1 +1], [+1 e ^{j2π /3} e ^{j4π /3} ] and [+1 e ^{j4π /3} e ^{j2π / 3} ] can be used.

The three length 3 OCC [+1 +1 +1], [+1 e ^{j2π /3} e ^{j4π /3} ], [+1 e ^{j4π /3} e ^{j2π /3} ] Each of the DM-RS associated with the PSBCH In case n ^SL _ID is divided by 3 and the remainder is 0, 1, and 2, respectively.

In relation to other cyclic shifts, the same configuration as that in D2D (Prose) will be possible.

[ Orthogonal sequence ( OCC ) and method 9 for cyclic shift ]

In this case, when a normal CP is used, 3 symbols out of 14 symbols in one subframe can be determined as symbols for transmitting the DM-RS.

Also, in this case, when the extended CP is used, 3 symbols among 12 symbols in one subframe may be determined as symbols for transmitting the DM-RS.

For this, a configuration (configuration #1) for transmitting DM-RS through two existing symbols in one subframe in the same way as D2D (Prose) through upper-stage signaling such as RRC (configuration #1) and a total of three symbols in one subframe It may be configured by selecting one of the configurations (configuration #2) for transmitting the DM-RS through.

As shown in Table 19, in consideration of DM-RS transmission for a total of three symbols in one subframe in DM-RS associated with PSBCH, three types of length 3 OCC [+1 +1 +1], [+1 e ^{j2π /3} e ^{j4π /3} ] and [+1 e ^{j4π /3} e ^{j2π / 3} ] can be used.

The three length 3 OCC [+1 +1 +1], [+1 e ^{j2π /3} e ^{j4π /3} ], [+1 e ^{j4π /3} e ^{j2π /3} ] Each of the DM-RS associated with the PSBCH In case n ^SL _ID is divided by 3 and the remainder is 0, 1, and 2, respectively.

In relation to other cyclic shifts, in case of DM-RS linked to PSBCH in D2D (Prose), if one of eight cyclic shift values is determined by performing a modular operation 8 on the quotient value obtained by dividing n ^SL _ID by 2 , in the case of DM-RS linked to PSBCH in V2X, one of 8 cyclic shift values can be determined by performing a modular operation 8 on the quotient value obtained by dividing n ^SL _ID by 3. In addition, in the case of DM-RS linked to PSBCH in D2D (Prose), modular operation 30 is performed on the quotient value obtained by dividing n ^SL _ID by 16, and 30 sequence shift patterns in group hopping (f) _ss ) if one of the values is determined, in the case of DM-RS linked to PSBCH in V2X, modular operation 30 is performed on the quotient value obtained by dividing n ^SL _ID by 24, and 30 sequence shifts in group hopping (sequence shift) ) pattern (f _ss ) value can be determined.

Here, each embodiment may be applied differently to each channel (PSCCH, PSSCH, PSDCH, PSBCH) to which the DM-RS is linked. For example, in the case of DM-RS associated with PSCCH and PSSCH, method 4 for the orthogonal sequence (OCC) and cyclic shift, method 5 for orthogonal sequence (OCC) and cyclic shift, orthogonal sequence (OCC) and cyclic shift One of 6 methods for On the other hand, in the case of DM-RS linked to PSBCH, method 7 for the orthogonal sequence (OCC) and cyclic shift, method 8 for orthogonal sequence (OCC) and cyclic shift, orthogonal sequence (OCC) and method 9 for cyclic shift One of them could be used.

에 의해 0, π/6, π/3, π/2, 4π/6, 5π/6, π, 7π/6만 쓰이므로, 360도의 각도에 대해 균등하게 배분되지 않는 단점이 있다. 따라서, 다음 표 20나 표 21을 통해서 표 6내지 표 19를 통해 결정되는 총 8가지의 cyclic shift를 위한 값 중 하나가 n_CS,λ를 지시하는 것이 아니라 아래 수학식 5에서 n⁽¹⁾ _DMRS 또는 n⁽²⁾ _DMRS,λ를 지시할 수도 있을 것이다. 즉 표 6 내지 표 19를 통해 결정된 총 8가지의 cyclic shift이 각각 0, 1, 2, 3, 4, 5, 6, 7일 경우 이는 n_CS,λ 값이 각각 0, 1, 2, 3, 4, 5, 6, 7인 것을 의미하였으나, 본 발명에서는 표 20를 따를 경우 표 6 내지 표 19를 통해 결정된 총 8가지의 cyclic shift이 각각 0, 1, 2, 3, 4, 5, 6, 7일 경우 이는 n⁽¹⁾ _DMRS 값이 각각 0, 2, 3, 4, 6, 8, 9, 10인 것을 의미할 수 있으며, 표 21을 따를 경우 표 6 내지 표 19를 통해 결정된 총 8가지의 cyclic shift이 각각 0, 1, 2, 3, 4, 5, 6, 7일 경우 이는 n⁽²⁾ _DMRS,λ값이 각각 0, 6, 3, 4, 2, 8, 10, 9인 것을 의미할 수 있다.Additionally, the value of n _CS,λ is determined from among a total of eight values through Tables 6 to 19, in this case, the formula

Since only 0, π/6, π/3, π/2, 4π/6, 5π/6, π, and 7π/6 are used by , there is a disadvantage that it is not evenly distributed for an angle of 360 degrees. Therefore, one of the values for a total of eight cyclic shifts determined through Tables 6 to 19 through Table 20 or Table 21 does not indicate n _CS,λ , but in Equation 5 below, n ⁽¹⁾ _DMRS Or it may indicate n ⁽²⁾ _DMRS,λ . That is, when a total of 8 cyclic shifts determined through Tables 6 to 19 are 0, 1, 2, 3, 4, 5, 6, 7, respectively, this is n _CS,λ The values were 0, 1, 2, 3, 4, 5, 6, and 7, respectively, but in the present invention, when Table 20 is followed, a total of 8 cyclic shifts determined through Tables 6 to 19 are 0 and 1, respectively. , 2, 3, 4, 5, 6, 7, this may mean that n ⁽¹⁾ _DMRS values are 0, 2, 3, 4, 6, 8, 9, 10, respectively, and when Table 21 is followed When a total of 8 cyclic shifts determined through Tables 6 to 19 are 0, 1, 2, 3, 4, 5, 6, 7, respectively, this is n ⁽²⁾ _DMRS,λ values are 0, 6, 3, It may mean 4, 2, 8, 10, 9.

Here, as shown in Equation 5, n _CS,λ determined by adding three values of n ⁽¹⁾ _DMRS , n ⁽²⁾ _DMRS,λ and n _PN and performing a modular operation 12 as follows cases will be possible.

1) When a total of 8 cyclic shifts determined through Tables 6 to 19 indicate n ⁽¹⁾ _DMRS #1

- Determination of n ⁽¹⁾ _DMRS value according to Table 20

- n ⁽²⁾ _DMRS,λ = 0

- n _PN = 0

2) When a total of 8 cyclic shifts determined through Tables 6 to 19 indicate n ⁽²⁾ _DMRS,λ #1

- n ⁽¹⁾ _DMRS = 0

- Determination of n ⁽²⁾ _DMRS,λ value according to Table 21

- n _PN = 0

3) A total of 8 cyclic shifts determined through Tables 6 to 19 are n ⁽¹⁾ _DMRS and n ⁽²⁾ _{DMRS, λ} when indicating #1

- Determination of n ⁽¹⁾ _DMRS value according to Table 20

- Determination of n ⁽²⁾ _DMRS,λ value according to Table 21

- n _PN = 0

4) When a total of 8 cyclic shifts determined through Tables 6 to 19 indicate n ⁽¹⁾ _DMRS #2

- Determination of n ⁽¹⁾ _DMRS value according to Table 20

- n ⁽²⁾ _DMRS,λ = 0

- n _PN is created differently for each DM-RS transmission symbol

5) When a total of eight cyclic shifts determined through Tables 6 to 19 indicate n ⁽²⁾ _DMRS,λ #2

- n ⁽¹⁾ _DMRS = 0

- Determination of n ⁽²⁾ _DMRS,λ value according to Table 21

- n _PN is created differently for each DM-RS transmission symbol

6) A total of 8 cyclic shifts determined through Tables 6 to 19 are n ⁽¹⁾ _DMRS And n ⁽²⁾ _{DMRS, λ} when indicating #2

- Determination of n ⁽¹⁾ _DMRS value according to Table 20

- Determination of n ⁽²⁾ _DMRS,λ value according to Table 21

- n _PN is created differently for each DM-RS transmission symbol

Among the above cases, when n _PNs are differently generated for each DM-RS transmission symbol, the UE within one subframe (or Transmission Time Interval (TTI)) in consideration of an environment in which the UE may have a very fast movement speed. This is to prevent the DM-RS transmitted by the . A detailed look at the methods for this is as follows.

Hereinafter, method 1 for differently generating n _PNs for each DM-RS transmission symbol according to the present invention will be defined.

According to method 1, as shown in Equation 6, considering that DM-RSs are generated in two symbols in one slot, which is the case illustrated in FIG. 5(a) or FIG. 5(b), 2 Two different n _PN values are defined in each slot regardless of the positions of the symbols. The first n _PN value is applied to the first symbol in which a DM-RS is transmitted in one slot, and the other n _PN value is applied to the second symbol in which the DM-RS is transmitted in one slot. In this case, l'=0 or 1.

Here, c(i) is a pseudo-random sequence defined as a Gold sequence having a length of order 31.

로 초기화된다.The pseudo-random sequence generator for the pseudo-random sequence is n ^PSSCH _ss = 0 at the beginning of each slot that satisfies

is initialized to

In this case, n ^PSSCH _ss means the number of a current slot in a subframe pool for sidelink. where n ^SA _ID may be a sidelink group destination identity.

Hereinafter, method 2 for differently generating n _PNs for each DM-RS transmission symbol according to the present invention will be defined.

According to method 2, as shown in Equation 7 below, considering that DM-RSs are generated in three symbols in one subframe, which is the case exemplified in (c) of FIG. Regardless, three different n _PN values are defined in each subframe. The first n _PN value is applied to the first symbol in which DM-RS is transmitted in one subframe, and the second group n _PN value is applied to the second symbol in which DM-RS is transmitted in one subframe, and the last The third n _PN value is a scheme applied to the third symbol in which a DM-RS in one subframe is transmitted. In this case, l'=0, 1, or 2.

Here, c(i) is a pseudo-random sequence defined as a Gold sequence having a length of order 31.

또는

로 초기화된다.The pseudo-random sequence generator for the pseudo-random sequence is generated at the beginning of every PSBCH subframe (a subframe transmitting PSBCH).

or

is initialized to

where N ^SL _ID may be a physical layer sidelink synchronization identity.

Hereinafter, method 3 for differently generating n _PNs for each DM-RS transmission symbol according to the present invention will be defined.

Method 3, as shown in Equation 8 below, defines a different n _PN value for each symbol in one slot for each symbol, and n _PN value for each symbol in the corresponding symbol in which the DM-RS is transmitted method to apply. This is applicable to all cases exemplified through FIGS. 5(a), 5(b) and 5(c). In this case, N ^SL _symb is the number of symbols in one slot in the SL (sidelink) (7 in the case of a normal CP, 6 in the case of an extended CP), and l=0,1,..., N ^SL _symb is a symbol index within one slot.

In Equation 8, n _s is n ^PSSCH _ss when the above equation is applied in DM-RS for PSSCH.

Meanwhile, in Equation 8, n _s has two values: 0 or 1 when the above Equation is applied in DM-RS for PSBCH.

Also, c(i) is a pseudo-random sequence defined as a Gold sequence having a length of order 31.

로 초기화된다.When Equation 8 is applied in DM-RS for PSSCH, the pseudo-random sequence generator for the pseudo-random sequence is generated at the beginning of each slot satisfying n ^PSSCH _ss = 0.

is initialized to

On the other hand, when Equation 8 is applied in DM-RS for PSBCH, the pseudo-random sequence generator for the pseudo-random sequence is generated at the beginning of every PSBCH subframe (a subframe transmitting PSBCH).

로 초기화된다.or

is initialized to

In this case, n ^PSSCH _ss means the number of a current slot in a subframe pool for sidelink. where n ^SA _ID is a sidelink group destination identity, N ^SL _ID may be a physical layer sidelink synchronization identity.

6 is a block diagram illustrating a wireless communication system in which an embodiment of the present invention is implemented.

Referring to FIG. 6 , the terminal 300 includes a radio frequency (RF) unit 305 , a processor 310 , and a memory 315 . The memory 315 is connected to the processor 310 and stores various information for driving the processor 310 . The RF unit 305 is connected to the processor 310 to transmit and/or receive a radio signal. For example, the RF unit 305 may receive the RRC connection reconfiguration message and the SIB posted herein from the base station 350 . In addition, the RF unit 305 may transmit the uplink signal posted herein to the base station 350 .

The processor 310 implements the proposed functions, processes and/or methods. In all embodiments of the present specification, the operation of the terminal 300 may be implemented by the processor 310 .

The memory 315 may store calculated values according to the equations and tables of the present specification, and may provide the calculated values to the processor 310 according to the request of the processor 310 .

The base station 350 includes a processor 355 , a memory 360 and an RF unit (radio frequency (RF) unit, 33 ). The memory 360 is connected to the processor 355 and stores various information for driving the processor 355 . The RF unit 365 is connected to the processor 355 to transmit and/or receive a radio signal. The processor 355 implements the proposed functions, processes and/or methods. In the above-described embodiment, the operation of the base station may be implemented by the processor 355 .

The processor may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and/or data processing devices. Memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The RF unit may include a baseband circuit for processing a radio signal. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) that performs the above-described function. A module may be stored in a memory and executed by a processor. The memory may be internal or external to the processor, and may be coupled to the processor by various well-known means.

According to an example of the present invention, the processor may determine the group hopping, orthogonal sequence (OCC) and cyclic shift values through the methods specified in Tables 6 to 19.

에 의해 0, π/6, π/3, π/2, 4π/6, 5π/6, π, 7π/6만 쓰이므로, 360도의 각도에 대해 균등하게 배분되지 않는 단점을 고려하여, 표 20나 표 21을 통해서 수학식 5에서 n⁽¹⁾ _DMRS 또는 n⁽²⁾ _DMRS,λ 중 하나 이상을 지시하도록 제어할 수도 있다.In addition, in the case of the cyclic shift n _CS,λ value in Tables 6 to 19, the method specified in Tables 6 to 19 is not directly applied, but the formula

Since only 0, π/6, π/3, π/2, 4π/6, 5π/6, π, and 7π/6 are used by In Equation 5 through Table 21, it is also possible to control to indicate at least one of n ⁽¹⁾ _DMRS or n ⁽²⁾ _DMRS,λ .

Although various embodiments of the present invention have been described focusing on 3GPP LTE or LTE-A systems, they may be applied to various mobile communication systems.

Claims (14)

In a method of transmitting a demodulation-reference signal (DM-RS) for V2X (vehicle-to-everything) communication,
The first DM-RS is determined based on the first group hopping related to the slot number of the first slot of the subframe, and based on the second group hopping related to the slot number and the offset of the first slot to generate a second DM-RS, wherein the first group hopping and the second group hopping apply different inputs in a pseudo-random sequence;
mapping the first DM-RS in a first symbol of a first slot of the subframe and mapping the second DM-RS in a second symbol of a first slot of the subframe;
A third DM-RS is determined based on a third group hopping associated with a slot number of a second slot of the subframe, and a fourth DM-RS is determined based on a fourth group hopping associated with the slot number of the second slot and the offset. - generating RS, wherein the third group hopping and the fourth group hopping apply different inputs in a pseudo-random sequence;
mapping the third DM-RS in a first symbol of a second slot of the subframe and mapping the fourth DM-RS in a second symbol of a second slot of the subframe; and
transmitting the mapped first DM-RS, the mapped second DM-RS, the mapped third DM-RS, and the mapped fourth DM-RS; and
The slot number of the first slot and the slot number of the second slot respectively correspond to the number of the current slot in the subframe pool for sidelink for the two slots in the subframe. Characterized in that, DM-RS transmission method.
According to claim 1,
The first group hopping associated with the slot number of the first slot and the third group hopping associated with the slot number of the second slot are expressed in the first equation

related to,
The second group hopping associated with the slot number of the first slot and the offset and the fourth group hopping associated with the slot number of the second slot and the offset are expressed by the second equation

related to,
c(x) in the first and second expressions represents a gold sequence having a length of 31 of the pseudo-random sequence order,
remind

DM-RS transmission method, characterized in that indicating the number of the current slot in the subframe pool for the sidelink.
3. The method of claim 2,
The first slot of the subframe is

is satisfied, and the second slot of the subframe is

However, k is a non-negative integer, characterized in that, DM-RS transmission method.
According to claim 1,
A first orthogonal sequence related to the first DM-RS, the second DM-RS, the third DM-RS, and the fourth DM-RS [+1 +1 +1 +1] or a second Applying the orthogonal sequence [+1 -1 +1 -1]; characterized in that it comprises a, DM-RS transmission method.
5. The method of claim 4,
The first orthogonal sequence [+1 +1 +1 +1] is set to be applied when an identifier of a modulo-2 operation becomes 0,
The second orthogonal sequence [+1 -1 +1 -1] is characterized in that it is set to be applied when the identifier of the modular-2 operation becomes 1.
The method of claim 1, further comprising: determining to transmit a V2X data channel to a target device; and
For the mapping of the first DM-RS, the second DM-RS, the third DM-RS, and the fourth DM-RS, the number of symbols in the first slot of the subframe and the second of the subframe determining the number of symbols in the slot;
The first DM-RS, the second DM-RS, the third DM-RS, and the fourth DM-RS are characterized in that they are related to a V2X data channel, a DM-RS transmission method.
According to claim 1,
For DM-RSs related to a V2X data channel, a DM-RS transmission method comprising the step of determining whether group hopping is possible.
In a method of transmitting a demodulation-reference signal (DM-RS) for V2X (vehicle-to-everything) communication,
The first DM-RS is determined based on the first group hopping related to the slot number of the first slot of the subframe, and based on the second group hopping related to the slot number and the offset of the first slot to generate a second DM-RS, wherein the first group hopping and the second group hopping apply different inputs in a pseudo-random sequence;
mapping the first DM-RS in a first symbol of a first slot of the subframe and mapping the second DM-RS in a second symbol of a first slot of the subframe;
A third DM-RS is determined based on a third group hopping associated with a slot number of a second slot of the subframe, and a fourth DM-RS is determined based on a fourth group hopping associated with the slot number of the second slot and the offset. - generating RS, wherein the third group hopping and the fourth group hopping apply different inputs in a pseudo-random sequence;
mapping the third DM-RS in a first symbol of a second slot of the subframe and mapping the fourth DM-RS in a second symbol of a second slot of the subframe; and
transmitting the mapped first DM-RS, the mapped second DM-RS, the mapped third DM-RS, and the mapped fourth DM-RS; and
that the slot number of the first slot and the slot number of the second slot correspond to the number of a current slot in a subframe pool for sidelinks for two slots in the subframe Characterized in, DM-RS transmission method.
9. The method of claim 8,
The first group hopping associated with the slot number of the first slot and the third group hopping associated with the slot number of the second slot are expressed in the first equation

related to,
The second group hopping associated with the slot number of the first slot and the offset and the fourth group hopping associated with the slot number of the second slot and the offset are expressed by the second equation

related to,
c(x) in the first and second expressions represents a gold sequence having a length of 31 of the pseudo-random sequence order,
remind

DM-RS transmission method, characterized in that indicating the number of the current slot in the subframe pool for the sidelink.
10. The method of claim 9,
The first slot of the subframe is

is satisfied, and the second slot of the subframe is

However, k is a non-negative integer, characterized in that, DM-RS transmission method.
9. The method of claim 8,
A first orthogonal sequence [+1 +1 +1 +1] or a second related to the first DM-RS, the second DM-RS, the third DM-RS, and the fourth DM-RS Applying the orthogonal sequence [+1 -1 +1 -1]; characterized in that it comprises a, DM-RS transmission method.
12. The method of claim 11,
The first orthogonal sequence [+1 +1 +1 +1] is set to be applied when an identifier of a modulo-2 operation becomes 0,
The second orthogonal sequence [+1 -1 +1 -1] is characterized in that it is set to be applied when the identifier of the modular-2 operation becomes 1.
In a method of transmitting a demodulation-reference signal (DM-RS) for V2X (vehicle-to-everything) communication,
A first DM-RS is determined based on a first group hopping related to a slot number of a first slot of a subframe, and a second DM-RS is determined based on a second group hopping related to a slot number and an offset of the first slot. generating a DM-RS, wherein the first DM-RS is mapped to a first symbol of a first slot of the subframe, and the second DM-RS is mapped to a second symbol of a first slot of the subframe mapped;
A third DM-RS is determined based on a third group hopping related to a slot number of a second slot of the subframe, and a fourth DM-RS is determined based on a fourth group hopping related to the slot number of the second slot and the offset. - generating an RS, wherein the third DM-RS is mapped to a first symbol of a second slot of the subframe, and the fourth DM-RS is mapped to a second symbol of a second slot of the subframe become;
A first orthogonal sequence [+1 +1 +1 +1] or a second related to the first DM-RS, the second DM-RS, the third DM-RS, and the fourth DM-RS applying an orthogonal sequence [+1 -1 +1 -1]; and
Including; transmitting the first DM-RS, the second DM-RS, the third DM-RS, and the fourth DM-RS;
that the slot number of the first slot and the slot number of the second slot correspond to the number of a current slot in a subframe pool for sidelinks for two slots in the subframe Characterized in, DM-RS transmission method.
14. The method of claim 13,
The first orthogonal sequence [+1 +1 +1 +1] is set to be applied when an identifier of a modulo-2 operation becomes 0,
The second orthogonal sequence [+1 -1 +1 -1] is characterized in that it is set to be applied when the identifier of the modular-2 operation becomes 1.

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