WO2019203609A1 - Method and terminal for transmitting demodulation-reference signal (dm-rs) through dm-rs transmission resource in wireless communication system, and method and base station for setting dm-rs transmission resource - Google Patents

Abstract

The present invention provides a method by which a first terminal transmits a demodulation-reference signal (DM-RS) in a wireless communication system, the method including: a step for generating the DM-RS; and a step for transmitting the generated DM-RS to a second terminal through a DM-RS transmission resource region, wherein the DM-RS transmission resource region is set on the basis of at least one among the speed, the latency-related requirements, and the frequency range (FR) of at least one among the first terminal and the second terminal.

Description

Method for transmitting DM-RS through DM-RS (DEMODULATION-REFERENCE SIGNAL) transmission resource in wireless communication system, method for setting UE and DM-RS transmission resource and base station

The following description relates to a wireless communication system, and more particularly, to a method for transmitting a DM-RS through a DM-RS transmission resource, a terminal, a method for setting the DM-RS transmission resource, and a base station.

As more communication devices demand larger communication capacities, there is a need for improved mobile broadband communication as compared to conventional radio access technology (RAT). In addition, massive machine type communications (mMTC), which connects multiple devices and objects to provide various services anytime and anywhere, is also one of the major issues to be considered in next-generation communication. In addition, a communication system design considering a service / UE that is sensitive to reliability and latency is being discussed. As described above, the introduction of next-generation RAT in consideration of Enhanced Mobile Broadband Communication (eMBB), mMTC, Ultra-Reliable and Low Latency Communication (URLLC), and the like, is referred to herein as NR for convenience. NR is an expression showing an example of 5G radio access technology (RAT).

The new RAT system including the NR uses an OFDM transmission scheme or a similar transmission scheme. The new RAT system may follow different OFDM parameters than the OFDM parameters of LTE. Alternatively, the new RAT system can follow the existing numeric / numerology of LTE / LTE-A but have a larger system bandwidth (eg, 100 MHz). Alternatively, one cell may support a plurality of neurology. That is, UEs operating with different neurology may coexist in one cell.

V2X (vehicle-to-everything) is a communication technology that exchanges information with other vehicles, pedestrians, infrastructure, etc. through wired / wireless communication, and V2V (vehicle-to-vehicle) and V2I (vehicle-to-vehicle). 4 types, such as -infrastructure, vehicle-to-network (V2N) and vehicle-to-pedestrian (V2P). V2X communication may be provided via a PC5 interface and / or a Uu interface.

In the present invention, considerations should be taken when designing a DM-RS structure to be used in an NR V2X system and a DM to be used in an NR V2X system while maintaining and using an RS (front-loaded / additional DM-RS and PTRS) structure in an existing NR system. -Propose a way to indicate the structure of the RS.

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 above will be clearly understood by those skilled in the art from the following description. Could be.

According to an embodiment of the present invention, a method for transmitting a demodulation-reference signal (DM-RS) by a first terminal in a wireless communication system, the method comprising: generating the DM-RS; And transmitting the generated DM-RS to a second terminal through a DM-RS transmission resource region. Wherein the DM-RS transmission resource region is based on at least one of a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal. It suggests how to be set.

The speed of at least one of the first terminal and the second terminal corresponds to an absolute speed or a relative speed, and the absolute speed or the relative speed is an average speed of at least one of the first terminal and the second terminal. , At least one of a maximum speed, a minimum speed, and an instantaneous speed may be set.

The DM-RS transmission resource region is set to a first DM-RS structure when the speed of at least one of the first terminal and the second terminal is higher than or equal to a threshold, and the first terminal and the second terminal are configured. If the speed of at least one of the terminals is lower than the threshold value may be set to the second DM-RS structure.

The method includes receiving configuration information regarding the DM-RS transmission resource region from a base station through higher layer signaling or physical layer signaling; It may further include.

Receiving the configuration information from the base station, receiving first information indicating a plurality of structures associated with the DM-RS transmission resource region, and second information indicating any one of the plurality of structures Receiving may include.

The DM-RS transmission resource region includes a first DM-RS structure and a second DM-RS structure, wherein the plurality of DM-RSs are arranged in a time division multiplexing (TDM) scheme. In the second DM-RS structure, a plurality of DM-RSs may be arranged in a frequency division multiplexing (FDM) scheme.

In the first DM-RS structure and the second DM-RS structure, the positions where the plurality of DM-RSs are arranged in the resource region are starting positions at which the first DM-RSs are arranged and intervals between the plurality of DM-RSs It may be set based on at least one of the start position and the interval of each of the remaining DM-RS except the first DM-RS in the plurality of DM-RS, and the position of each of the plurality of DM-RS. .

When the DM-RS transmission resource region is set to the first DM-RS structure, among the plurality of DM-RSs, the DM-RS corresponding to each of the plurality of antenna ports is set to be arranged in different frequency regions, and the When the DM-RS transmission resource region is set to the second DM-RS structure, the DM-RS corresponding to each of the plurality of antenna ports may be set to be arranged in different time domains.

An embodiment of the present invention provides a first terminal for transmitting a demodulation-reference signal (DM-RS) in a wireless communication system, including a transceiver and a processor, and the processor controls the transceiver: the DM-RS Generate and transmit the generated DM-RS to the second terminal through the DM-RS transmission resource region, wherein the DM-RS transmission resource region is at least one of the speed of the first terminal and the second terminal. The present invention proposes a first terminal configured based on at least one of a latency related requirement and a frequency range (FR).

According to an embodiment of the present invention, a method for transmitting configuration information by a base station in a wireless communication system includes at least one of a first terminal and a second terminal, a requirement relating to latency, and a frequency range Based on at least one or more or a combination thereof, setting a DM-RS transmission resource region, and transmitting configuration information related to the set resource region to the first terminal. It proposes a method comprising the steps.

An embodiment of the present invention, in a base station for transmitting configuration information in a wireless communication system, comprising a transceiver and a processor, the processor controls the transceiver: the speed of at least one of the first terminal and the second terminal Based on at least one or more of a latency, a latency related requirement, and a frequency range, or a combination thereof, and set a DM-RS transmission resource region and set the resource region. A base station for transmitting configuration information related to the first terminal is proposed. In addition to the above conditions, a DM-RS transmission resource region may be set as well as configuration information related to the set resource region.

According to the present invention, a DM-RS transmission resource region (DM-RS structure) is set in consideration of a speed, a latency related requirement, a FR, and a frequency range of at least one of the first terminal and the second terminal. ), It is possible to provide a communication system optimized for a communication environment. In addition, the UE can improve the performance of receiving the DM-RS and can suppress the allocation of more resources than necessary to transmit / receive the DM-RS.

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

BRIEF DESCRIPTION OF THE DRAWINGS The drawings appended hereto are for the purpose of providing an understanding of the present invention and for illustrating various embodiments of the present invention and for describing the principles of the present invention together with the description of the specification.

1 shows an example of a frame structure in NR.

2 shows an example of a resource grid in NR.

3 is a diagram for explaining sidelink synchronization.

4 shows a time resource unit through which the sidelink synchronization signal is transmitted.

5 shows an example of a sidelink resource pool.

6 shows a scheduling scheme according to a sidelink transmission mode.

Figure 7 shows the selection of sidelink transmission resources.

8 shows the contents related to the transmission of the sidelink PSCCH.

9 shows the contents related to the transmission of the PSCCH in the sidelink V2X.

10 is a diagram illustrating an example of a front-loaded DM-RS and an additional DM-RS structure.

11 is a diagram illustrating an example of a 4-V (4 vertical) DM-RS structure.

12 is a diagram illustrating an example of a 2-H (2 horizontal) DM-RS structure.

13 is a diagram illustrating an example of a 1-H DM-RS structure.

14 is a diagram illustrating an example of a 4-H DM-RS structure.

15 is a diagram illustrating an example of a 3-V DM-RS structure.

16 is a diagram illustrating an example of a 5-V DM-RS structure.

17 is a diagram illustrating an example of a 4-V DM-RS structure.

18 is a diagram illustrating an example of a 1-H DM-RS structure.

19 is a diagram illustrating an example of a 4-H DM-RS structure.

20 illustrates multiplexing of DM-RSs in a V DM-RS structure.

21 is a diagram illustrating multiplexing of DM-RSs in an H DM-RS structure.

22 is a flowchart illustrating one embodiment of the present invention.

23 is a flowchart illustrating one embodiment of the present invention.

24 is a flowchart illustrating one embodiment of the present invention.

25 is a flowchart describing one embodiment of the present invention.

Fig. 26 is a diagram illustrating the apparatus of the present invention.

Hereinafter, downlink (DL) means communication from a base station (BS) to a user equipment (UE), and uplink (UL) means communication from a UE to a BS. In downlink, a transmitter may be part of a BS, and a receiver may be part of a UE. In uplink, the transmission is part of the UE, and the receiver may be part of the BS. In the present specification, a BS may be represented by a first communication device and a UE by a second communication device. BS may be a fixed station, Node B, evolved-NodeB (eNB), Next Generation NodeB (gNB), base transceiver system (BTS), access point (AP), network or 5G network node, AI system, It may be replaced by terms such as RSU (road side unit), robot, and the like. In addition, the UE may include a terminal, a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS), a wireless terminal (WT), and a machine (MTC). -Type Communication (M2M) device, Machine-to-Machine (M2M) device, Device-to-Device (D2D) device, vehicle (vehicle), robot (robot), can be replaced with terms such as AI module.

The following technologies include various wireless connections such as Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier FDMA (SC-FDMA), and the like. Can be used for the system. CDMA may be implemented with a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented in a wireless technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of Evolved UMTS (E-UMTS) using E-UTRA and LTE-A (Advanced) / LTE-A pro is an evolution of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolution of 3GPP LTE / LTE-A / LTE-A pro.

For clarity, the description will be based on 3GPP communication systems (eg, LTE-A, NR), but the technical spirit of the present invention is not limited thereto. LTE refers to technology after 3GPP TS 36.xxx Release 8. In detail, LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR means technology after TS 38.xxx Release 15. LTE / NR may be referred to as a 3GPP system. "xxx" means standard document detail number. LTE / NR may be collectively referred to as 3GPP system.

In this disclosure, a node refers to a fixed point that can communicate with a UE to transmit / receive radio signals. Various types of BSs may be used as nodes regardless of their names. For example, a node may be a BS, an NB, an eNB, a pico-cell eNB (PeNB), a home eNB (HeNB), a relay, a repeater, or the like. Also, the node may not be a BS. For example, it may be a radio remote head (RRH), a radio remote unit (RRU). RRHs, RRUs, and the like generally have a power level lower than that of the BS. At least one antenna is installed at one node. The antenna may mean a physical antenna or may mean an antenna port, a virtual antenna, or an antenna group. Nodes are also called points.

In the present specification, a cell refers to a certain geographic area or radio resource for which one or more nodes provide communication services. A "cell" in a geographic area may be understood as coverage in which a node can provide services using a carrier, and a "cell" of radio resources is a bandwidth (frequency) that is a frequency size configured by the carrier. bandwidth, BW). Downlink coverage, which is a range in which a node can transmit valid signals, and uplink coverage, which is a range in which a valid signal can be received from a UE, depends on a carrier carrying the signal, so that the coverage of the node is determined by the radio resources used by the node. It is also associated with the coverage of the "cell". Thus, the term "cell" can sometimes be used to mean coverage of a service by a node, sometimes a radio resource, and sometimes a range within which a signal using the radio resource can reach a valid strength.

In this specification, communicating with a specific cell may mean communicating with a BS or a node that provides a communication service to the specific cell. In addition, the downlink / uplink signal of a specific cell means a downlink / uplink signal from / to a BS or a node providing a communication service to the specific cell. A cell that provides uplink / downlink communication service to a UE is particularly called a serving cell. In addition, the channel state / quality of a specific cell means a channel state / quality of a channel or communication link formed between a BS or a node providing a communication service to the specific cell and a UE.

Meanwhile, a "cell" associated with a radio resource may be defined as a combination of DL resources and UL resources, that is, a combination of a DL component carrier (CC) and a UL CC. The cell may be configured with DL resources alone or with a combination of DL resources and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resource (or DL CC) and the carrier frequency of the UL resource (or UL CC) is corresponding. It may be indicated by system information transmitted through the cell. Here, the carrier frequency may be the same as or different from the center frequency of each cell or CC. Hereinafter, a cell operating on a primary frequency is referred to as a primary cell (Pcell) or a PCC, and a cell operating on a secondary frequency (or SCC) is referred to as a secondary cell. cell, Scell) or SCC. The Scell may be set after a UE performs a Radio Resource Control (RRC) connection establishment process with a BS and an RRC connection is established between the UE and the BS, that is, after the UE is in an RRC_CONNECTED state. have. Here, the RRC connection may mean a path through which the RRC of the UE and the RRC of the BS may exchange RRC messages with each other. Scell may be configured to provide additional radio resources to the UE. Depending on the capabilities of the UE, the Scell may form a set of serving cells for the UE with the Pcell. In case of the UE that is in the RRC_CONNECTED state but the carrier aggregation is not configured or does not support the carrier aggregation, there is only one serving cell configured only for the Pcell.

The cell supports a unique radio access technology. For example, transmission / reception according to LTE radio access technology (RAT) is performed on an LTE cell, and transmission / reception according to 5G RAT is performed on a 5G cell.

Carrier aggregation technology refers to a technology that aggregates and uses a plurality of carriers having a system bandwidth smaller than a target bandwidth for broadband support. Carrier aggregation is one of a base frequency band divided into a plurality of orthogonal subcarriers in that downlink or uplink communication is performed using a plurality of carrier frequencies, each forming a system bandwidth (also called a channel bandwidth). It is distinguished from an OFDMA technology that performs downlink or uplink communication on a carrier frequency. For example, in the case of OFDMA or orthogonal frequency division multiplexing (OFDM), one frequency band having a predetermined system bandwidth is divided into a plurality of subcarriers having a predetermined subcarrier spacing, and information / data is divided into the plurality of subcarriers. The frequency bands mapped in the subcarriers of Mn and the information / data are mapped are transmitted to a carrier frequency of the frequency band through frequency upconversion. In the case of wireless carrier aggregation, frequency bands each having its own system bandwidth and carrier frequency may be used for communication, and each frequency band used for carrier aggregation may be divided into a plurality of subcarriers having a predetermined subcarrier spacing. .

3GPP-based communication standards include upper layers of the physical layer (e.g., medium access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol) protocol data convergence protocol (PDCP) layer, radio resource control (RRC) layer, service data adaptation protocol (SDAP), non-access stratum (NAS) layer) Downlink physical channels corresponding to resource elements carrying a piece of information and downlink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from an upper layer are defined. . For example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), a physical multicast channel (PMCH), a physical control format indicator channel (physical control) A format indicator channel (PCFICH) and a physical downlink control channel (PDCCH) are defined as downlink physical channels, and a reference signal and a synchronization signal are defined as downlink physical signals. A reference signal (RS), also referred to as a pilot, refers to a signal of a predetermined special waveform that the BS and the UE know from each other. For example, a cell specific RS, UE- UE-specific RS, positioning RS (PRS), channel state information RS (CSI-RS), demodulation reference signal (DM-RS) Is defined as downlink reference signals. Meanwhile, the 3GPP-based communication standard corresponds to uplink physical channels corresponding to resource elements carrying information originating from an upper layer and resource elements used by the physical layer but not carrying information originating from an upper layer. Uplink physical signals are defined. For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are the uplink physical channels. A demodulation reference signal (DM-RS) for uplink control / data signals and a sounding reference signal (SRS) used for uplink channel measurement are defined.

In this specification, a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) are used for downlink control information (DCI) and downlink data of a physical layer. It can mean a collection of time-frequency resources or a set of resource elements, respectively. In addition, the physical uplink control channel (physical uplink control channel), the physical uplink shared channel (physical uplink shared channel, PUSCH) and the physical random access channel (physical random access channel) is uplink control information (uplink control information) of the physical layer , UCI), a set of time-frequency resources or a set of resource elements that carry uplink data and random access signals, respectively. Hereinafter, when the UE transmits an uplink physical channel (eg, PUCCH, PUSCH, PRACH) may mean that a DCI, uplink data, or random access signal is transmitted on or through the corresponding uplink physical channel. Receiving an uplink physical channel by the BS may mean receiving a DCI, uplink data, or random access signal on or through the corresponding uplink physical channel. The BS transmitting a downlink physical channel (eg, PDCCH, PDSCH) is used in the same sense as transmitting DCI or uplink data on or through the corresponding downlink physical channel. Receiving a downlink physical channel by the UE may mean receiving DCI or uplink data on or through the corresponding downlink physical channel.

In this specification, a transport block is a payload for a physical layer. For example, data given to the physical layer from an upper layer or medium access control (MAC) layer is basically referred to as a transport block.

In this specification, HARQ is a type of error control method. HARQ-ACK transmitted through downlink is used for error control on uplink data, and HARQ-ACK transmitted through uplink is used for error control on downlink data. The transmitting end performing the HARQ operation waits for an acknowledgment (ACK) after transmitting data (eg, a transport block and a codeword). The receiver performing the HARQ operation sends an ACK only when data is properly received, and sends a negative ACK (NACK) when an error occurs in the received data. When the transmitting end receives the ACK, it can transmit (new) data, and when receiving the NACK, it can retransmit the data. After the BS transmits the scheduling information and the data according to the scheduling information, a time delay occurs until the ACK / NACK is received from the UE and the retransmission data is transmitted. This time delay occurs due to the time required for channel propagation delay, data decoding / encoding. Therefore, when new data is sent after the current HARQ process is completed, a time delay causes a gap in data transmission. Therefore, a plurality of independent HARQ processes are used to prevent gaps in data transmission during the time delay period. For example, if there are seven transmission opportunities between initial transmission and retransmission, the communication device may operate seven independent HARQ processes to perform data transmission without a gap. By utilizing a plurality of parallel HARQ processes, UL / DL transmission can be performed continuously while waiting for HARQ feedback for previous UL / DL transmission.

In this specification, channel state information (CSI) refers to information that may indicate the quality of a radio channel (also called a link) formed between the UE and the antenna port. CSI includes channel quality indicator (CQI), precoding matrix indicator (PMI), CSI-RS resource indicator (CRI), SSB resource indicator (SSBRI) , At least one of a layer indicator (LI), a rank indicator (RI), and a reference signal received power (RSRP).

In this specification, frequency division multiplexing (FDM) may mean transmitting / receiving signals / channels / users on different frequency resources, and time division multiplexing (CDM) This may mean transmitting / receiving signals / channels / users in different time resources.

In the present invention, frequency division duplex (FDD) refers to a communication scheme in which uplink communication is performed on an uplink carrier and downlink communication is performed on a downlink carrier linked to the uplink carrier, and time division is performed. The time division duplex (TDD) refers to a communication scheme in which uplink communication and downlink communication are performed by dividing time on the same carrier.

Background, terminology, abbreviations, etc., used in this specification, may be referred to those described in standard documents published prior to the present invention. For example, reference may be made to a document corresponding to 3GPP TS 36, 24, 38 series (http://www.3gpp.org/specifications/specification-numbering).

Frame structure

1 is a diagram illustrating an example of a frame structure in NR.

The NR system can support multiple neurology. Here, the numerology may be defined by subcarrier spacing and cyclic prefix (CP) overhead. In this case, the plurality of subcarrier spacings may be derived by scaling the basic subcarrier spacing to an integer N (or μ). Also, even if we assume that we do not use very low subcarrier spacing at very high carrier frequencies, the used numerology may be selected independently of the cell's frequency band. In addition, in the NR system, various frame structures according to a number of numerologies may be supported.

Hereinafter, orthogonal frequency division multiplexing (OFDM) neuralology and frame structure that can be considered in an NR system will be described. Multiple OFDM numerologies supported in the NR system may be defined as shown in Table 1. Μ and cyclic prefix for the bandwidth part are obtained from the RRC parameters provided by the BS.

NR supports a number of pneumatics (eg, subcarrier spacing) to support various 5G services. For example, if the subcarrier spacing is 15 kHz, it supports wide area in traditional cellular bands, and if the subcarrier spacing is 30 kHz / 60 kHz, it is dense-urban, lower latency Latency and wider carrier carrier bandwidth are supported, and when the subcarrier spacing is 60 kHz or higher, it supports bandwidth greater than 24.25 GHz to overcome phase noise.

Resource grid

2 shows an example of a resource grid in NR.

Referring to FIG. 2, for each subcarrier spacing and carrier, a resource grid of N ^{size, μ} _grid * N ^RB _sc subcarriers and 14 * 2 ^μ OFDM symbols is defined, where N ^{size, μ} _grid is defined from BS. Is indicated by RRC signaling. N ^{size, μ} _grid can vary between uplink and downlink as well as the subcarrier spacing setting μ . There is one resource grid for the subcarrier spacing μ , the antenna port p, and the transmission direction (uplink or downlink). Each element of the resource grid for subcarrier spacing μ and antenna port p is referred to as a resource element and is uniquely identified by an index pair ( k , l ), where k is in the frequency domain And l refers to the symbol location in the frequency domain relative to the reference point. The resource elements k and l for the subcarrier spacing μ and the antenna port p correspond to the physical resources and the complex value a ^{(p, μ)} _{k, l} . A resource block (RB) is defined as N ^RB _sc = 12 consecutive subcarriers in the frequency domain.

In consideration of the fact that the UE may not support the wide bandwidth to be supported in the NR system at one time, the UE may be configured to operate in a portion of the cell's frequency bandwidth (hereinafter, referred to as a bandwidth part (BWP)). .

Bandwidth part (BWP)

In an NR system, up to 400 MHz may be supported per one carrier. If a UE operating on such a wideband carrier always operates with a radio frequency (RF) module for the entire carrier, UE battery consumption may increase. Alternatively, when considering various use cases (eg, eMBB, URLLC, mMTC, V2X, etc.) operating in one wideband carrier, there is a difference in the number of numerologies (e.g. subcarrier spacing) within the carrier. Can be supported. Alternatively, the capability for the maximum bandwidth may vary for each UE. In consideration of this, the BS may instruct the UE to operate only in some bandwidths rather than the entire bandwidths of the wideband carriers, and this bandwidth is referred to as a bandwidth part (BWP). In the frequency domain, the BWP is a subset of contiguous common resource blocks defined for the neuron μi in bandwidth part i on the carrier, with one numerology (e.g., subcarrier spacing, CP length, slot / mini-slot persistence). Period) can be set.

Meanwhile, the BS may configure one or more BWPs in one carrier configured for the UE. Or, when UEs are concentrated in a specific BWP, some UEs may be moved to another BWP for load balancing. Alternatively, in consideration of frequency domain inter-cell interference cancellation between neighboring cells, some BWPs of the cell may be set in the same slot by excluding some spectrum from the entire bandwidth. That is, the BS may configure at least one DL / UL BWP to a UE associated with a wideband carrier, and may perform physical (Physically) at least one DL / UL BWP among DL / UL BWP (s) configured at a specific time point. Switch to another configured DL / UL BWP (L1 signaling, MAC), by layer control signal L1 signaling, MAC layer control signal MAC control element (CE), or RRC signaling). Or by setting a timer value to allow the UE to switch to a predetermined DL / UL BWP when the timer expires. An activated DL / UL BWP is particularly called an active DL / UL BWP. The UE may not receive a configuration for DL / UL BWP in a situation such as when the UE is in an initial access process or before the RRC connection of the UE is set up. In this situation, the UE assumes that the DL / UL BWP is called an initial active DL / UL BWP.

Acquisition of Sidelink Terminal Synchronization

In time division multiple access (TDMA) and frequency division multiple access (FDMA) systems, accurate time and frequency synchronization is essential. If time and frequency synchronization is not accurate, intersymbol interference (ISI) and intercarrier interference (ICI) can be caused, resulting in poor system performance. The same applies to V2X. In V2X, sidelink synchronization signal (SLSS) is used in the physical layer, and the master information block-sidelink-V2X (MIB-SL-V2X) is used in the radio link control (RLC) layer. Can be used.

3 shows an example of a source of synchronization or a reference of synchronization in V2X.

As shown in FIG. 3, in V2X, a terminal may be directly synchronized to a global navigation satellite systems (GNSS), or may be indirectly synchronized to a GNSS through a terminal (in network coverage or out of network coverage) directly synchronized to the GNSS. have. When the GNSS is set as the synchronization source, the terminal may calculate the DFN and the subframe number using Coordinated Universal Time (UTC) and a (pre-set) direct frame number (DFN) offset.

Alternatively, the terminal may be synchronized directly to the base station or to another terminal time / frequency synchronized to the base station. For example, when the terminal is in network coverage, the terminal may receive synchronization information provided by the base station and may be directly synchronized to the base station. Thereafter, the synchronization information may be provided to another adjacent terminal. When the base station timing is set as a criterion for synchronization, for synchronization and downlink measurement, the terminal may transmit a cell associated with the frequency (if within cell coverage at the frequency), a primary cell or a serving cell (out of cell coverage at the frequency). Can be followed).

The base station (serving cell) may provide a synchronization setting for the carrier used for V2X sidelink communication. In this case, the terminal may follow the synchronization setting received from the base station. If no cell is detected in the carrier used for the V2X sidelink communication and no synchronization setting is received from the serving cell, the terminal may follow a preset synchronization setting.

Alternatively, the terminal may be synchronized to another terminal that has not obtained synchronization information directly or indirectly from the base station or GNSS. The source and preference of the synchronization may be preset to the terminal or may be set via a control message provided by the base station.

The synchronization signal SLSS and the synchronization information will now be described.

The SLSS is a sidelink specific sequence, and may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS).

Each SLSS may have a physical layer sidelink synchronization ID, and its value may be any one of 0 to 335. The synchronization source may be identified depending on which of the above values is used. For example, 0, 168, and 169 may mean GNSS, 1 to 167 are base stations, and 170 to 335 are out of coverage. Alternatively, among the values of the physical layer sidelink synchronization ID, 0 to 167 may be values used by the network, and 168 to 335 may be values used outside the network coverage.

4 illustrates a time resource unit in which an SLSS is transmitted. Herein, the time resource unit may mean a slot in 5G of a subframe of LTE / LTE-A, and the details thereof are based on the contents of the 3GPP TS 36 series or 38 series document. Physical sidelink broadcast channel (PSBCH) is a basic (system) information (for example, information related to SLSS, duplex mode (Duplex Mode, DM), TDD UL / DL configuration that the terminal needs to know first before transmitting and receiving sidelink signals) , Resource pool related information, type of application related to SLSS, subframe offset, broadcast information, etc.). The PSBCH may be transmitted on the same time resource unit as the SLSS or on a subsequent time resource unit. DM-RS can be used for demodulation of PSBCH.

Sidelink Transmission Mode

Sidelinks have transport modes 1, 2, 3, and 4.

In transmission mode 1/3, the base station performs resource scheduling on the terminal 1 through the PDCCH (more specifically, DCI), and the terminal 1 performs D2D / V2X communication with the terminal 2 according to the resource scheduling. UE 1 may transmit sidelink control information (SCI) to UE 2 through a physical sidelink control channel (PSCCH), and then may transmit data based on the SCI through a physical sidelink shared channel (PSSCH). Transmission mode 1 may be applied to D2D, and transmission mode 3 may be applied to V2X.

The transmission mode 2/4 may be referred to as a mode in which the UE schedules itself. More specifically, the transmission mode 2 is applied to the D2D, and the UE may select a resource by itself in the configured resource pool to perform the D2D operation. The transmission mode 4 is applied to the V2X, and after performing a sensing process, the terminal selects a resource by itself in the selection window and may perform a V2X operation. After transmitting the SCI to the terminal 2 through the PSCCH, the terminal 1 may transmit the data based on the SCI through the PSSCH. Hereinafter, the transmission mode can be abbreviated as mode.

While control information transmitted from the base station to the terminal through the PDCCH is referred to as downlink control information (DCI), control information transmitted from the terminal to another terminal through the PSCCH may be referred to as SCI. SCI may carry sidelink scheduling information. There may be various formats in SCI, for example SCI format 0 and SCI format 1.

SCI format 0 may be used for scheduling of PSSCH. In SCI format 0, the frequency hopping flag (1 bit), resource block allocation and hopping resource allocation fields (the number of bits may vary depending on the number of resource blocks in the sidelink), time resource pattern (7 bits), MCS (modulation and coding scheme, 5 bits), a time advance indication (11 bits), a group destination ID (8 bits), and the like.

SCI format 1 may be used for scheduling of PSSCH. In SCI format 1, priority (3 bits), resource reservation (4 bits), frequency resource position of initial transmission and retransmission (the number of bits may vary depending on the number of subchannels in the sidelink), initial transmission and Time gap between initial transmission and retransmission (4 bits), MCS (5 bits), retransmission index (1 bit), reserved information bits, and the like. The reserved information bits may be abbreviated as reserved bits below. The reserved bits can be added until the bit size of SCI format 1 is 32 bits.

SCI format 0 may be used for transmission modes 1 and 2, and SCI format 1 may be used for transmission modes 3 and 4.

Sidelink Resource Pool

5 shows an example of UE1, UE2 and sidelink resource pools that they use to perform sidelink communication.

In FIG. 5 (a), a UE refers to a network equipment such as a base station for transmitting and receiving a signal according to a terminal or a sidelink communication scheme. The terminal may select a resource unit corresponding to a specific resource in a resource pool representing a set of resources and transmit a sidelink signal using the resource unit. The receiving terminal UE2 may be configured with a resource pool in which UE1 can transmit a signal, and detect a signal of UE1 in the corresponding pool. Here, the resource pool may be notified by the base station when UE1 is in the connection range of the base station. When the UE1 is outside the connection range of the base station, another UE may notify or may be determined as a predetermined resource. In general, a resource pool is composed of a plurality of resource units, and each terminal may select one or a plurality of resource units and use them for transmitting their own sidelink signals. The resource unit may be as illustrated in FIG. 5 (b). Referring to FIG. 5 (b), it can be seen that total frequency resources are divided into NFs and total time resources are divided into NTs so that a total of NF * NT resource units are defined. In this case, the resource pool is repeated every NT time resource unit. In particular, one resource unit may appear periodically and repeatedly as shown. Alternatively, in order to obtain a diversity effect in the time or frequency dimension, the inductance of a physical resource unit to which one logical resource unit is mapped may change in a predetermined pattern over time. In this resource unit structure, a resource pool may mean a set of resource units that can be used for transmission by a terminal to which a sidelink signal is to be transmitted.

Resource pools can be divided into several types. First, they may be classified according to contents of sidelink signals transmitted from each resource pool. For example, the contents of the sidelink signal may be divided, and a separate resource pool may be configured for each. As the content of the sidelink signal, there may be a scheduling assignment or a physical sidelink control channle (PSCCH), a sidelink data channel, and a discovery channel. The SA provides information such as the location of resources used for transmission of a sidelink data channel that is transmitted by a transmitting terminal and other information such as a modulation and coding scheme (MCS), a MIMO transmission scheme, and a timing advance (TA) required for demodulation of other data channels. It may be a signal that includes. This signal may be transmitted multiplexed with sidelink data on the same resource unit. In this case, the SA resource pool may mean a pool of resources in which the SA is multiplexed with the sidelink data and transmitted. Another name may be called a sidelink control channel or a physical sidelink control channel (PSCCH). The sidelink data channel (or physical sidelink shared channel (PSSCH)) may be a pool of resources used by a transmitting terminal to transmit user data. If an SA is multiplexed and transmitted along with sidelink data on the same resource unit, only a sidelink data channel having a form other than SA information may be transmitted in a resource pool for the sidelink data channel. In other words, REs that were used to transmit SA information on individual resource units in the SA resource pool can still be used to transmit sidelink data in the sidelink data channel resource pool. The discovery channel may be a resource pool for a message that allows a transmitting terminal to transmit information such as its ID so that the neighboring terminal can discover itself.

Even if the content of the sidelink signal is the same, different resource pools may be used according to the transmission / reception attributes of the sidelink signal. For example, even when the same sidelink data channel or discovery message is determined, the transmission timing of the sidelink signal (for example, is transmitted at the time of receiving the synchronization reference signal or is transmitted by applying a constant TA there) or a resource allocation method. (E.g., whether the eNB assigns the transmission resources of the individual signals to the individual transmitting UEs or if the individual transmitting UEs select their own individual signaling resources within the pool), and the signal format (e.g. each sidelink signal has one hour The number of symbols occupied by the resource unit, the number of time resource units used for transmission of one sidelink signal), the signal strength from the eNB, and the transmission power strength of the sidelink UE may be further divided into different resource pools. Sidelink transmission mode 1, the transmission resource region is set in advance, or the eNB designates a transmission resource region in the way that the eNB directly indicates the transmission resources of the sidelink transmitting UE in sidelink communication, The method of directly selecting a transmission resource is called sidelink transmission mode 2. In the case of sidelink discovery, when the eNB directly indicates a resource, type 1 when the UE directly selects a transmission resource in a type 2, a preset resource region, or a resource region indicated by the eNB will be referred to as type 1.

In V2X, sidelink transmission mode 3 based on centralized scheduling and sidelink transmission mode 4 of distributed scheduling are used.

6 shows a scheduling scheme according to these two transmission modes. Referring to FIG. 6, in the transmission mode 3 of the centralized scheduling method of FIG. 6A, when a vehicle requests a sidelink resource from a base station (S901a), the base station allocates a resource (S902a) and other resources through the resource. Transmission to the vehicle is performed (S903a). In the centralized transmission scheme, resources of other carriers may also be scheduled. On the contrary, in the distributed scheduling method of FIG. 6 (b) corresponding to transmission mode 4, the vehicle senses a resource and a resource pool previously set from the base station (S901b), and then selects a resource to be used for transmission (S902b). The transmission may be performed to another vehicle through the selected resource (S903b).

In this case, as shown in FIG. 7, a transmission resource of the next packet is selected as a transmission resource selection. In V2X, two transmissions are performed per MAC PDU. When selecting a resource for initial transmission, resources for retransmission are reserved with a certain time gap. The terminal identifies the transmission resources reserved by the other terminal or resources used by the other terminal through sensing in the sensing window, and after randomly excluding them in the selection window, randomly among the resources having low interference among the remaining resources. You can select a resource.

For example, the UE may decode a PSCCH including information on a period of reserved resources in a sensing window and measure a PSSCH RSRP in resources determined periodically based on the PSCCH. Resources whose PSSCH RSRP value exceeds a threshold may be excluded in the selection window. Thereafter, the sidelink resource may be randomly selected from the remaining resources in the selection window.

Alternatively, RSSI (Received signal strength indication) of the periodic resources in the sensing window is measured to identify, for example, resources with low interference corresponding to the lower 20%. The sidelink resource may be randomly selected from among the resources included in the selection window among the periodic resources. For example, this method can be used when decoding of the PSCCH fails.

For details, refer to 3GPP TS 36.213 V14.6.0 document 14, which is incorporated into the specification as a prior art of the present invention.

Transmit and Receive PSCCH

Sidelink transmission mode 1 UE may transmit a PSCCH (or sidelink control signal, Sidelink Control Information (SCI)) through the resources configured from the base station. Sidelink transmission mode 2 UE is configured (configured) resources to be used for sidelink transmission from the base station. In addition, the PSCCH may be transmitted by selecting a time frequency resource from the configured resource.

In the sidelink transmission mode 1 or 2, the PSCCH period may be defined as shown in FIG. 8.

Referring to FIG. 8, the first PSCCH (or SA) period may start at a time resource unit separated by a predetermined offset indicated by higher layer signaling from a specific system frame. Each PSCCH period may include a PSCCH resource pool and a time resource unit pool for sidelink data transmission. The PSCCH resource pool may include the last time resource unit of the time resource unit indicated that the PSCCH is transmitted in the time resource unit bitmap from the first time resource unit of the PSCCH period. In the resource pool for sidelink data transmission, in case of Mode 1, a time resource unit used for actual data transmission may be determined by applying a time-resource pattern for transmission (T-RPT) or a time-resource pattern (TRP). . As shown, if the number of time resource units included in the PSCCH period excluding the PSCCH resource pool is larger than the number of T-RPT bits, the T-RPT may be repeatedly applied, and the last applied T-RPT is the remaining time resource. It can be applied by truncating the number of units. The transmitting terminal transmits at the position where the T-RPT bitmap is 1 in the indicated T-RPT, and one MAC PDU transmits four times.

In the case of V2X, that is, sidelink transmission mode 3 or 4, unlike the sidelink, PSCCH and data (PSSCH) are transmitted by the FDM scheme. In V2X, it is important to reduce delay due to the characteristics of vehicle communication. Therefore, the PSCCH and data are FDM transmitted on different frequency resources on the same time resource. An example of such a transmission scheme is illustrated in FIG. 9. One of a scheme in which the PSCCH and data are not directly adjacent to each other as shown in FIG. 9 (a) or a scheme in which the PSCCH and data are directly adjacent to each other as shown in FIG. 9 (b) may be used. . The basic unit of such transmission is a subchannel, which is a resource unit having one or more RB sizes on a frequency axis on a predetermined time resource (eg, a time resource unit). The number of RBs included in the subchannel, that is, the size of the subchannel and the start position on the frequency axis of the subchannel are indicated by higher layer signaling.

Meanwhile, in inter-vehicle communication, a periodic message type CAM (Cooperative Awareness Message) message, an event triggered message type DENM message, or the like may be transmitted. The CAM may include basic vehicle information such as dynamic state information of the vehicle such as direction and speed, vehicle static data such as dimensions, exterior lighting state, and route details. The size of the CAM message may be 50-300 bytes. The CAM message is broadcast and the latency must be less than 100ms. The DENM may be a message generated in a sudden situation such as a vehicle breakdown or accident. The size of the DENM can be less than 3000 bytes, and any vehicle within the transmission range can receive the message. In this case, the DENM may have a higher priority than the CAM, and in this case, having a high priority may mean transmitting a higher priority when a simultaneous transmission occurs from one UE perspective, or priority among a plurality of messages. May attempt to send a higher message in time priority. In many UEs, a higher priority message may be less interference than a lower priority message, thereby reducing the probability of reception error. In the case of a security overhead, CAM can have a larger message size than otherwise.

Sidelink congestion control

The sidelink communication wireless environment may be easily congested according to the density of a vehicle, an increase in the amount of transmission information, and the like. At this time, various methods are applicable to reduce congestion. One example is distributed congestion control.

In distributed congestion control, a terminal grasps a congestion state of a network and performs transmission control. At this time, congestion control considering the priority of traffic (eg, a packet) is necessary.

Specifically, each terminal measures the channel congestion (CBR), and determines the maximum value (CRlimitk) of the channel utilization rate (CRk) that can be occupied by each traffic priority (eg, k) according to the CBR. For example, the terminal may derive a maximum value CRlimitk of the channel utilization rate for each traffic priority based on the CBR measurement value and a predetermined table. In the case of relatively high-priority traffic, the maximum value of the greater channel utilization can be derived.

Thereafter, the terminal may perform congestion control by limiting the sum of channel utilization rates of the traffics whose priority k is lower than i to a predetermined value or less. This approach places stronger channel utilization restrictions on relatively low priority traffic.

In addition, the terminal may use a method such as adjusting the transmission power, dropping the packet, determining whether to retransmit, adjusting the transmission RB size (MCS adjustment), or the like.

In the present invention, considerations should be taken when designing a DM-RS structure to be used in an NR V2X system and a DM to be used in an NR V2X system while maintaining and using an RS (front-loaded / additional DM-RS and PTRS) structure in an existing NR system. We propose a method that can indicate an RS structure. For convenience of description, the following description will be made based on a V2X terminal, but the proposed method may also be used for a fixed node such as a general device-to-device (D2D) terminal, an Internet of Things (IoT) terminal, or a relay or a base station (eg, eNB, gNB). Can be. Unless otherwise stated, the method proposed below may be extended to other types of wireless terminals and other scenarios.

DM-RS and PTRS in NR Systems

When designing a DM-RS for demodulation of data in an NR system, a front-loaded DM-RS structure was introduced to position the DM-RS in front of the symbol to meet low latency requirements (see 3gpp TR-38.211). . In addition, an additional DM-RS structure has been introduced that additionally places the same pattern on the time axis as the front-load DM-RS to estimate the channels of fast UEs.

10 shows examples of the front-loaded DM-RS 1012 and additional DM-RS 1013 structures. FIG. 10 shows the structure of a DM-RS when one front-loaded DM-RS 1012 and one additional DM-RS 1013 enter a subframe (RAN1 # 90 Chairman's Notes). 10 shows a structure of a DM-RS including one front-loaded DM-RS 1012 and one additional DM-RS 1013 in one subframe. In FIG. 10, the first region 1011, 1021, and the like does not include data, and the second region 1012, 1013, 1022, 1023, etc., indicates the position of the DM-RS in the data region. In FIG. 10, the left examples 1010 represent three control symbols, and the right examples 1020 represent two control symbols.

Tables 2 and 3 show the allowable number and positions of additional DM-RSs according to the data symbol length. Specifically, Table 2 below shows the PUSCH DM-RS positions.

for single-symbol DM-RS, Table 3 shows PDSCH DM-RS positions

for single-symbol DM-RS. The number and positions of DM-RSs that can be added in symbols according to data symbol length (PUSCH / PDSCH) can be found in Tables 2 and 3 below. The numbers in Tables 2 and 3 indicate the positions of OFDM symbols in one subframe. Meanwhile, in Table 3 below, type B may indicate a case in which only a data signal is transmitted without a control signal.

In the NR system, in addition to the front-loaded DM-RS structure described above, in order to compensate for performance degradation of the system due to carrier phase error (CPE) due to impairment in RF hardware when introducing mm wave (mmW), one OFDM in a subframe A PTRS (Phase Tracking Reference Signal) structure, which uses serial RSs on all of the subcarriers, is also introduced. At this time, the density of PTRS is given as Table 4 and Table 5 below (see 3gpp TR-38.214). As can be seen in Tables 4 and 5 below, the frequency density of the PTRS is determined according to the bandwidth scheduled in the data, and the time density is determined according to the MCS. Tables 4 and 5 below show the density of PTRS in the symbol. Specifically, Table 4 below shows a time density of PT-RS as a function of scheduled MCS, and Table 5 shows a frequency density of PT-RS as a function of scheduled bandwidth.

DM-RS in NR V2X Systems

In an NR V2X system (e.g., an environment in which UEs move fast and use high carrier frequencies), the phase offset due to the Doppler effect and the frequency offset changes rapidly with time, and the structure of the DM-RS for estimating the phase offset You need to design. In order to compensate for the phase offset that changes with time, it is necessary to consider the density of DM-RS in terms of time.

In the existing LTE V2X system, the subframe structure based on the LTE PUSCH structure can be used, and the existing Rel. In V2X, two DM-RSs are added at equal intervals in the LTE-based PUSCH structure to cover high relative speeds, and so-called 4-V (4 vertical) DM-RS structures as shown in FIG. 11 are used.

This method has a disadvantage in that performance is degraded in a very high speed mobile environment because the DM-RS is not present in every symbol. For example, if the UE is unable to monitor all symbols as the UE moves at high speed, the UE succeeds in monitoring only the symbols where the DM-RS is not located and fails to monitor the symbols where the DM-RS is located. The UE may not be able to decode the DM-RS. To solve this problem, a 2-H (two horizontal DM-RS per RB / subframe) DM-RS structure has been proposed. (3gpp R1-155907, Ericsson) Meanwhile, FIG. 12 shows an example of a 2-H (2 horizontal) DM-RS structure.

In the present invention, considerations should be taken when designing a DM-RS structure to be used in an NR V2X system, and the RS (front-loaded / additional DM-RS and PTRS) structure in an existing NR system may be used in an NR V2X system. We propose a way to indicate (or inform) the DM-RS structure.

In an embodiment of the present invention, the method may include generating a DM-RS, and transmitting the generated DM-RS to a second terminal through a DM-RS transmission resource region. Here, the first terminal may be a Tx UE and the second terminal may be an Rx UE. The DM-RS transmission resource region may be set based on at least one of a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal. have. Here, the DM-RS transmission resource region may include a first DM-RS structure and a second DM-RS structure. For example, the first DM-RS structure has a plurality of DM-RSs arranged in a time division multiplexing (TDM) scheme, and the second DM-RS structure has a plurality of DM-RSs arranged in a frequency division multiplexing (FDM) scheme. It may be arranged. In another example, the first DM-RS structure may be a V (vertical) DM-RS structure, and the second DM-RS structure may be an H (horizontal) DM-RS structure. As another example, the first DM-RS structure is any one of various embodiments of the V DM-RS structure described in the present invention, and the second DM-RS structure is the structure of the H DM-RS structure described in the present invention. It may be any one of various embodiments.

As described above, in the NR V2X system, the DM-RS may use a V structure and / or an H structure. For example, in the NR V2X system, the DM-RS may be arranged in the DM-RS transmission resource region based on the V DM-RS structure and / or the H DM-RS structure. Which structure the NR V2X system uses (ie, whether to use the V DM-RS structure or the H DM-RS structure) and / or the number of DM-RSs to use within one subframe in each structure And how to apply location and the like may vary by the speed of the UE (set (determined) based on the speed of the UE). For example, when the speed of the UE is below a certain speed (e.g., when the UE moves below or below a predetermined threshold), the V DM-RS structure is used, and the speed of the UE is above a certain speed (eg Very fast, when the UE moves at a speed above or above a predetermined threshold). The V DM-RS structure or the H DM-RS structure may give an indication or information by using the RS structure in the existing NR system. In addition, the UE in this document may be a wireless communication device that can be carried by a user, or may be a vehicle terminal device (eg, an On-Board Unit (OBU)) included in and / or outside the vehicle, and type is not limited to this.

When the base station configures a DM-RS transmission resource region (eg, DM-RS structure) and overhead, as described above, the speed of at least one UE (eg, Tx UE, Rx UE, and / or Relay UE) is determined. It can be set (determined) as a reference. The speed of the at least one UE may be an absolute speed of a Tx UE transmitting a message or a relative speed with a neighbor UE (eg, an Rx UE, a relay UE). Here, the relative speed may be a difference between the speed of the Tx UE and the speed of the neighbor UE. The speed of at least one of the first terminal (eg, Tx UE) and the second terminal (eg, Rx UE, Relay UE) may correspond to an absolute speed or a relative speed. The absolute speed or the relative speed may be set based on an average speed, a maximum speed, a minimum speed, an instantaneous speed, or a combination thereof of at least one of the first terminal and the second terminal.

For example, when the (average) relative speed with the neighboring UE is below a certain speed, phase estimation is possible even with a relatively small density of DM-RSs on the time axis, so that the DM-RS transmission resource region may be configured in a V DM-RS structure. Can be set to As another example, when the (average) relative speed with the neighboring UE is below a predetermined threshold value, even if a low time density DM-RS structure is used for phase estimation, the base station (or another entity) may use the DM-RS. The DM-RS transmission resource region for transmission may be set to a V DM-RS structure.

In the above-described method, the present invention provides a moving speed of a Tx UE transmitting a DM-RS and / or an Rx UE receiving a DM-RS and a relay UE in a communication environment in which a Tx UE, an Rx UE, and / or a relay UE may move. In this regard, since the DM-RS transmission resource region (DM-RS structure) is set, it is possible to transmit the DM-RS in a form in which the Rx UE and the relay UE can easily receive the DM-RS. In other words, since the Rx UE and the relay UE set the DM-RS transmission resource region (DM-RS structure) in consideration of whether or not it is easy to receive the DM-RS, the Rx UE and the relay UE set the DM-RS. It becomes possible to transmit the DM-RS in a form that is easy to receive the RS. Accordingly, the wireless communication system according to the present invention improves the performance of receiving the DM-RS by the Rx UE and the relay UE, and has a technical effect of suppressing allocating more resources than necessary to transmit / receive the DM-RS. Can provide.

The DM-RS transmission resource region is set to a first DM-RS structure when the speed of at least one of the first terminal and the second terminal is higher than or equal to a threshold, and among the first terminal and the second terminal. If at least one of the speeds is lower than the threshold, the second DM-RS structure may be set. The DM-RS structure may be set by a base station. Here, the first DM-RS structure and the second DM-RS structure may be any one of various embodiments of the V DM-RS structure described in the present invention or any one of various embodiments of the H DM-RS structure. .

The DM-RS transmission resource region (or DM-RS structure) may be set based on the UE type (or the type of Tx UE, Rx UE, Relay UE). For example, when the UE is a road-side unit (RSU), since the UE may be fixed, it may be regarded as a case where the speed of the UE is relatively slow. In this case, as an example, the base station may set the DM-RS transmission resource region to the V DM-RS structure.

In addition, as described above, when the base station sets the overhead or sets the amount (size) of transmission resources corresponding to an example of the transmission resource region of the DM-RS, at least one UE (eg, Tx UE, Rx UE, and / or relay UE) can be set (determined) based on the speed. For example, the overhead of the DM-RS is a symbol (or a subframe, a TTI) in one time domain (eg, subframe, TTI, short TTI) when the (average) relative speed with the neighboring UE is less than or equal to the first threshold. If a (mean time domain of size smaller than a short TTI) is used and the (average) relative speed of the UE is greater than or equal to (above) the first threshold and less than or equal to or less than the second threshold, b (a <b You can set this by using) symbols. As another example, the overhead of DM-RS is to use a symbol in one subframe when the (average) relative speed with neighboring UE is less than x, and b (a < It can be set by using b) symbols. At this time, if the UE speed is very fast, in order to estimate the rapidly changing phase, the number of DM-RS symbols used in one subframe is used to increase the time-axis density (eg, time density) of the DM-RS. Although this can be increased, this may cause a problem in which the DM-RS overhead is greatly increased. Therefore, by using all of the subcarriers in the subframe as the DM-RS, the phase can be estimated by continuously positioning the DM-RS on the time axis without significantly increasing the DM-RS overhead. As such, when the (average) speed of the UE is z or more, the H DM-RS structure may be configured.

According to the aforementioned criteria, that is, the speed of at least one terminal, the DM-RS transmission resource region (or DM-RS structure) may be variously set as follows, and requirements related to latency, which will be described later, and FR (Frequency) In the case where the DM-RS transmission resource region is set based on other criteria such as Range), reference may be made to the following examples.

For example, in the case of the V DM-RS structure, DL-DMRS-add-pos is 3 and PUSCH duration in symbols is 12, 13, or 14 in Table 6 below in the current NR system (the number of PDCCH symbols per subframe is If two,

= 2), i.e., by indicating (or informing) the front-loaded DM-RS and three additional DM-RSs, the 4-V DM-RS structure shown in FIG. 11 can be expressed. Table 6 below shows the PUSCH DM-RS positions.

for single-symbol DM-RS. Meanwhile, the contents described based on Table 6 below may also be applied to Table 2 described above.

As another example, in the case of the H DM-RS structure, in Table 5 of the current NR system, the frequency density is indicated as 0.5, and the 2-H DM-RS structure as illustrated in FIG. 12 described above may be represented. In the H DM-RS structure, the frequency density may be determined by frequency selectivity, and the value may have a value other than 2 or 4 defined in the current NR system (eg, 0.5, 1, or 0.25). 13 shows an example ( frequency density = 1 (1-H DM-RS structure, one horizontal DM-RS per RB / subframe)), and FIG. 14 shows another example ( frequency density = 0.25 (4-H DM-RS structure, four horizontal DM-RS per RB / subframe)).

As described above, in an NR V2X system, i) V (DM-RS structure) ii) H DM-RS structure, or iii) DM-RS structure using V (DM-RS structure) and H (DM-RS structure) together. Etc. can be used. The DM-RS structure using the V (DM-RS structure) and H (DM-RS structure) together may be a structure in which the RS is arranged in a cross shape in the DM-RS transmission resource region. In other words, it may be a structure in which the V (DM-RS structure) and H (DM-RS structure) are combined.

The base station configures configuration information about a resource region (eg, 1-V DM-RS structure, NV DM-RS structure, 1-H DM-RS structure, MH DM-RS structure, etc.) allocated for the aforementioned DM-RS transmission. May be transmitted to a first terminal (eg, a Tx UE) through higher layer signaling or physical layer signaling. For example, the base station may determine whether to indicate the DM-RS transmission resource region through higher layer signaling or physical layer signaling according to the speed of the terminal. For example, when the terminal moves at a speed higher than or equal to the threshold, it may be necessary to change the DM-RS transmission resource area frequently, and in such a case, the base station needs to send information more frequently. It can be transmitted through layer signaling. As another example, when the terminal moves at a speed below the threshold (below), since the terminal may be regarded as being in a relatively less flexible communication environment, configuration information may be transmitted through higher layer signaling. In addition, the base station may signal a specific resource pool, a DM-RS structure usable for transmitting a message on a specific carrier, and / or overhead to the first terminal through a physical layer or a higher layer signal.

The base station transmits first information indicating a plurality of structures associated with the resource region allocated for the DM-RS transmission to the first terminal, and then transmits the second information indicating any one of the plurality of structures to the first terminal. 2 may be additionally transmitted to the terminal. For example, the first information includes information (table) that maps any identifier or indicator to a 1-V DM-RS structure, an NV DM-RS structure, a 1-H DM-RS structure, an MH DM-RS structure, and the like. The second information may include an identifier or an indicator mapped to the 1-V DM-RS structure, the NV DM-RS structure, the 1-H DM-RS structure, the MH DM-RS structure, and the like. As another example, information (table) in which the first terminal has already mapped an identifier or indicator mapped with a 1-V DM-RS structure, an NV DM-RS structure, a 1-H DM-RS structure, and an MH DM-RS structure In this situation, the first terminal may receive the second information from the base station.

In this case, as shown in the above example, which (DM-RS) structure of each NR V2X UEs is used, the absolute speed or relative speed of the UE, or delay spread, frequency offset, Doppler spread, latency requirement / budget, TTI (Transmission Time Interval) length (the number of symbols available in the slot) or the number of antenna ports used by other terminals in the vicinity, type of service or application, type / type of counterpart terminal to communicate, message It may be determined by the type / type of a transmitting terminal, a request of a receiving UE, or channel state information (CSI), a rank indicator (RI), speed, interference information, etc. fed back by the receiving UE. In addition, DM to be used in one subframe in the V (DM-RS structure) or H DM-RS structure, or (VH) DM-RS structure using V (DM-RS structure) and H (DM-RS structure) together. The number and location of the -RS may also vary.

As such, in a terminal (Tx UE) that intends to transmit a message when V2X terminals are transmitted and received in an NR V2X system, the DM (Tx UE) according to the type of service (or type of service that the Rx UE wants to receive) is sent to the DM. -RS structure and overhead can be adjusted. Or, in a terminal (Rx UE) to receive a message transmission, the DM-RS structure and overhead are adjusted based on a certain value (eg, arbitrary value or predetermined value) received by the terminal (Tx UE or Rx UE). Can be set). To this end, the Tx UE may signal the service type and target coverage information of the message it transmits to the Rx UE as a physical layer signal or a higher layer signal (eg, RRC signaling). Alternatively, the Tx UE may explicitly signal the DM-RS structure and overhead to the Rx UE as a physical layer signal or a higher layer signal. Such information may be transmitted by being included in a control signal (eg, Physical Sidelink Control Channel (PSCCH)) or a MAC layer control area (eg, Medium Access Control Control Element (MAC CE)). Meanwhile, when the above information is transmitted in the MAC layer control region, the corresponding indication is not an DM-RS structure of a packet currently being transmitted but an indication (or information) of a DM-RS structure (packet) to be transmitted next. Can be.

As described above, when transmitting and receiving messages of V2X terminals in an NR V2X system, the DM-RS structure and overhead are, for example, at the request of a Tx UE, an Rx UE, a Relay UE, and / or a base station (eg, eNB, gNB). Can be set (determined). As another example, the DM-RS structure and overhead may be set between the Tx UEs or the Rx UEs with values previously signaled by the data transmitting terminal or the receiving terminal. In this case, as an example, a network (eg, a base station) may signal a specific resource pool, a DM-RS structure that can be used to transmit a message on a specific carrier, and / or overhead to a UE as a physical layer signal or a higher layer signal. (Eg, RRC signaling). As another example, information on the specific resource pool, DM-RS structure, overhead, etc. that can be used for message transmission on a specific carrier may be provided by the Tx UE, Rx UE, Relay UE, and / or a base station (eg, eNB, gNB). It may be predetermined.

When setting the DM-RS structure and overhead, as described above may be set based on the speed of the UE (eg, Tx UE, Rx UE, and / or Relay UE). The speed of the UE may be an absolute speed of a UE transmitting a message or may be a relative speed with a neighboring UE. The aforementioned absolute speed and / or relative speed may be speed based on average speed, maximum speed, minimum speed, instantaneous speed, or a combination thereof.

For example, when the average relative speed with the neighboring UE is below a certain speed, phase estimation can be performed even with a relatively low density DM-RS on the time axis, so that the V DM-RS structure can be set. In this case, the overhead of DM-RS is to use a symbol in one subframe when the (average) relative speed with neighboring UE is less than x, and b (a < It can be set by using b) symbols. In this case, when the UE speed is very fast, the number of DM-RS symbols used in one subframe may be increased to increase the time-base density of the DM-RS to estimate the rapidly changing phase. In this case, the DM-RS overhead may increase significantly. Therefore, by using all of the subcarriers in the subframe as the DM-RS, the phase can be estimated by continuously positioning the DM-RS on the time axis without significantly increasing the DM-RS overhead. As such, when the (average) speed of the UE is z or more, the H DM-RS structure may be configured. The DM-RS structure may be set based on the UE type. For example, when the UE is a road-side unit (RSU), since the UE may be fixed, it may be regarded as a case where the speed of the UE is relatively slow, and thus a V DM-RS structure may be configured. have.

The DM-RS structure may be set based on a waveform and / or target coverage of a service provided. For example, an H DM-RS structure may be set when OFDM is used as a waveform, and a V DM-RS structure may be set when SC-FDM is used as the waveform. As another example, when the target coverage is wide, since there is a high probability of using SC-FDM, which is advantageous in terms of Peak to Average Power Ratio (PAPR), it is possible to set the V DM-RS structure. On the contrary, when the target coverage is narrow, the H DM-RS structure can be set. On the other hand, whether the target coverage is wide or narrow can be determined (determined) based on a predetermined threshold. The DM-RS structure may be set based on latency requirement of received data or Proximity Service (ProSe) Priority Per Packet (PPPP). For example, a V DM-RS structure may be configured for a message requiring a relatively short (or long) latency or a message requiring a relatively high (or low) PPPP. At this time, the position of the DM-RS may also be set based on the latency requirement or PPPP of the received data. For example, if fast transmission is required in terms of latency requirement, the DM-RS may be located in front of the subframe. That is, a packet to be transmitted with low latency may use a front-loaded DM-RS structure in an NR system. As described above, the DM-RS structure may be set to a latency requirement (eg, a service requirement determined based on PPPP), or may be determined based on the time remaining until the delay limit required. For example, if an initially available resource is available, a different RS pattern (rather than a front-loaded RS) may be used, but if a resource is available after a long time, the front-loaded RS may be used for fast decoding and HARQ-ACK. have. In this case, reTX (re-transmission) policy is also considered. For example, if there is a lot of latency budget, reTX is expected to be possible and initial TX is a bit aggressive, but if latency budget is insufficient, it needs to succeed at once. Therefore, RS pattern or resource amount used can be transmitted conservatively. For example, when the latency budget is greater than or equal to the threshold, the DM-RS transmission resource region is set so that a small number of DM-RSs are arranged, and the latency budget is less than or equal to the threshold. In the DM-RS transmission resource region can be set so that a large number of DM-RSs are arranged.

The DM-RS structure may be set based on a unicast / groupcast / broadcast environment. For example, in the case of unicast, a DM-RS structure may be configured according to an absolute speed of a Tx UE transmitting a message or a relative speed with an Rx UE receiving a message. The setting regarding the H DM-RS structure or the V DM-RS structure according to the speed may be made as described above. As another example, in the case of groupcast / broadcast, the DM-RS structure may be set to the H DM-RS structure or the V DM-RS structure according to the absolute speed of the UE transmitting the message.

The DM-RS structure may be set based on the region where the UE is located. For example, the H DM-RS structure may be set for a UE in a fast environment (eg, freeway), and the V DM-RS structure may be set for a UE in a slow environment (eg, urban). have. In this case, the wireless communication system according to the present invention can set the DM-RS transmission resource region even if the actual speed of the UE is not known, and the consumption of resources required to determine (identify) the speed of the UE in real time is reduced. It can provide a technical effect that can be suppressed. Here, the setting regarding the region may be determined in advance (set) or may be determined (set) / added / changed / updated by an entity different from the UE such as an RSU, a service infrastructure, a base station, or another UE.

The DM-RS structure may be set based on a frequency range. For example, in case of FR1 (first frequency range), the V DM-RS structure may be set, and in case of FR2 (second frequency range), the H DM-RS structure may be set. Here, the setting regarding the frequency range may be determined (set) in advance, or may be determined (set) / added / changed / updated by an entity different from the UE such as an RSU, a service infrastructure, a base station, or another UE.

In the above description, the V DM-RS structure may also be considered as a phase tracking reference signal (PTRS) structure using RS consecutively on a time axis using all of one OFDM subcarrier in a subframe (or may be used). This PTRS structure may be adaptively determined by signaling by a transmitting terminal (Tx UE). The setting criterion may be the absolute speed of the transmitting terminal (Tx UE) transmitting the message described above or the (average) relative speed of the receiving terminal (Rx UE) receiving the message.

As described above, the V DM-RS or H DM-RS structure that can be used in the NR V2X system can be set as the following indication. The base station may instruct or inform the UE (eg, Tx UE, Rx UE, Relay UE) of the DM-RS transmission resource region as follows. (indication or inform)

The base station may indicate or inform that the DM-RS transmission resource region is set to the following V DM-RS structure.

For example, the base station may indicate or inform that the DM-RS transmission resource region is set to the 1-V DM-RS structure. In existing NR systems, the

According to the value, a front-loaded DM-RS location in a time resource (eg, a subframe) is determined. In an NR V2X system, a pool specific or sidelink terminal may be indicated by a base station (eg, eNB, gNB). In other words, the base station

Information indicating the location of the front-loaded DM-RS in the subframe determined according to the value may be transmitted to the sidelink terminal. In this case, in the NR V2X system, unlike the front-loaded DM-RS, in consideration of AGC (Automatic Gain Control), it is possible to arrange (# 1 ~ # 12) the DM-RS “after” than the start symbol of the data. .

As another example, the base station may indicate or inform that the DM-RS transmission resource region is set to the N-V DM-RS structure. The number of DM-RSs that can be used in one time resource (eg, a subframe) may be indicated by the eNB to the pool-specific or sidelink UE. In other words, the base station may transmit information indicating the number of DM-RSs available in one time resource to the sidelink terminal.

In the first DM-RS structure and the second DM-RS structure, the positions where the plurality of DM-RSs are arranged in the resource region are starting positions at which the first DM-RSs are arranged and intervals between the plurality of DM-RSs It may be set based on at least one of the start position and the interval of each of the remaining DM-RS except the first DM-RS in the plurality of DM-RS, and the position of each of the plurality of DM-RS. . The DM-RS located next to the first DM-RS location within the subframe is set to be positioned at a fixed period (X), the offset value (e.g., Y1, Y2,…) is set, or the correct ( Alternatively, individual DM-RS positions can be specified. Alternatively, it can be specified to be evenly distributed at all times. To this end, the Tx UE may signal the DM-RS location it transmits to the Rx UE as a physical layer or a higher layer signal. Alternatively, the Tx UE may explicitly signal the DM-RS location to the Rx UE as a physical layer or higher layer signal. For example, the information may be included in a control signal (PSCCH) or in a MAC layer control region (MAC CE). When transmitted in the MAC layer control region, the corresponding indication may be an indication of a DM-RS location to be transmitted next, not a DM-RS location of a packet currently being transmitted. FIG. 15 shows an example of a DM-RS position of an NV DM-RS structure (3-V DM-RS structure (first DM-RS position: # 3, X = 4)), and FIG. 16 is NV DM- Another example of expressing the DM-RS position of the RS structure (5-V DM-RS structure (first DM-RS position: # 2, Y1 = 2, Y2 = 4, Y3 = 7, Y4 = 9)) is shown. 17 shows another example representing a DM-RS position of an N-V DM-RS structure (4-V DM-RS structure (DM-RS position: # 1, # 3, # 10, # 12)).

The base station may indicate or inform that the DM-RS transmission resource region is set to the following H DM-RS structure.

For example, the base station may indicate or inform that the DM-RS transmission resource region is set to the 1-H DM-RS structure. In the existing NR system, the DM-RS frequency density is determined according to the values of Tables 5 and / or 6. In the NR V2X system, the DM-RS frequency density may be indicated by the base station (eg, eNB, gNB) to the pool-specific or sidelink terminal. In other words, the base station may transmit information indicating a DM-RS frequency density to the sidelink terminal. At this time, the 1-H DM-RS structure may indicate that the frequency density value is indicated by 1. In addition, in NR V2X system, DM-RS can be arranged by using one subcarrier except the first symbol and the last symbol in consideration of AGC / Gap, etc., and it indicates (# 0 ~ # 11) the subcarrier to be used. Can be. FIG. 18 shows an example (1-H DM-RS structure (frequency density: 1, subcarrier position: # 4)) representing a DM-RS location of a 1-H DM-RS structure.

As another example, the base station may indicate or inform that the DM-RS transmission resource region is set to the M-H DM-RS structure. The number and location of subcarriers that can be used for the DM-RS in one time resource (eg, a subframe) may be indicated by the base station (eg, eNB, gNB) to the pool-specific or sidelink UE. In other words, the base station may transmit information indicating the number and location of subcarriers that can be used for the DM-RS in one time resource to the sidelink terminal. Based on the first DM-RS position in the subframe, the next DM-RS is set to be positioned at a fixed period (X), the offset value (eg Y1, Y2,…) is set, or (Or individual) DM-RS position can be specified. Alternatively, the positions of the plurality of DM-RSs may be set such that the plurality of DM-RSs are evenly distributed. The following is an example. FIG. 19 illustrates an example of expressing a DM-RS position of a 4-H DM-RS structure (a 4-H DM-RS structure (frequency density: 0.25, subcarrier position: # 1, X: 3)).

When the resource region allocated for DM-RS transmission is set to the first DM-RS structure, a frequency region (eg, sub-carrier) in which DM-RSs corresponding to each of the plurality of antenna ports are different from each other among the plurality of DM-RSs Unit is configured to be disposed in the unit, and the resource region allocated for the DM-RS transmission is set to the second DM-RS structure, the DM-RS corresponding to each of the plurality of antenna ports are different from each other ; symbol unit). When DM-RS is configured in a V2X terminal in an NR V2X system, multiplexing of DM-RSs between UEs and multi-port support at one terminal may be required. In the case of the V DM-RS structure, for example, as shown in FIG. 20, RSs are arranged in a comb form, and through Orthogonal Cover Code (OCC), multiplexing of DM-RSs between UEs and multi-ports in one UE (UE) 4 port) can be supported. 20 illustrates multiplexing of DM-RSs in a V DM-RS structure.

However, in the H DM-RS structure, if there is only one RE in one resource block RB, the above operation may be difficult. Therefore, in the H DM-RS structure, two REs may be completely pasted at a frequency and an orthogonal cover code (OCC) may be used to generate two ports. 21 shows multiplexing of DM-RSs in the H DM-RS structure.

The number of antenna ports that can be used by such a UE may be predetermined or a network (eg, a base station) may be signaled to terminals by a physical layer or a higher layer signal. Alternatively, the DM-RS structure of the user (ie, the UE) may be selected in consideration of the maximum antenna port that the UE can use in comparison with the neighboring terminals through sensing.

As described above, NV DM combining two types of vertical DM-RS and horizontal DM-RS to designate a more flexible DM-RS location, such as when considering multiplexing between UEs or supporting multi-port in one terminal. -RS structure, MH DM-RS structure can be considered. Alternatively, when a fast moving UE needs a wide coverage, phase tracking may be performed through the H DM-RS structure and demodulation may be performed through the V DM-RS structure. In the N-V DM-RS structure and the M-H DM-RS structure, the N and M values and thus the correct position of the DM-RS can be signaled by the PSCCH. However, if the number of bits is too large, some N and M combinations and the correct DM-RS location may be signaled in the RRC. For example, when the number of signaling bits required for DM-RS indication in the PSCCH is 4 bits, a base station (eg, eNB, gNB) may signal a higher layer signaling signal (eg, RRC signaling) for 16 different combinations. have.

As described above, the DM-RS structure, overhead, and / or location of corresponding UEs according to the speed, service type, latency requirement, PPPP, target coverage, waveform, etc. of V2X UEs are predetermined or networked (eg, The base station may be signaled to the terminals through a physical layer or a higher layer signal. In addition, the DM-RS indication method is shortened by support for short TTI (eg, 2/3/7 symbols TTI), support for dynamically variable TTI, and support for high frequency communication such as millimeter wave (mmW). The same may be applied to a transmission time interval (TTI).

In addition, as described above, the number and location of DM-RSs of UEs are predetermined, or a network (eg, a base station) is signaled to the terminals, in addition to efficient DM-RS resource allocation between the terminals (ie, DM- Allocate a resource region for RS transmission), a specific UE may select a DM-RS configuration method. For example, when a specific UE succeeds in SCI (Sidelink Control Information) decoding including information of DM-RS (or PTRS), based on a DM-RS (or PTRS) RSRP measurement value of a corresponding UE (Tx UE). Alternatively, when the Rx UE transmits a message based on the PPPP, the DM-RS pattern of the corresponding message may be punctured / rate matching with respect to the DM-RS of the Tx UE. Information on puncturing / rate matching may be provided by the SCI, and a network (eg, a base station) may be signaled to terminals by a physical layer or a higher layer signal. The base station may transmit control information (eg, SCI, DCI, etc.) including information on puncturing / rate matching to at least one terminal through a physical layer signal and / or a higher layer signal (eg, RRC signaling).

It is obvious that examples of the proposed scheme described above may also be regarded as a kind of proposed schemes as they may be included as one of the implementation methods of the present invention. In addition, although the above-described proposal schemes may be independently implemented, some proposal schemes may be implemented in combination (or merge). Information on whether the proposed methods are applied (or information on rules of the proposed methods) is informed by the base station through a predefined signal (eg, a physical layer signal or a higher layer signal) to the terminal or the transmitting terminal to the receiving terminal. Rules can be defined.

22 is a flowchart illustrating an operation of a terminal associated with the above-described embodiments of the present invention. The terminal may perform step S2201 and perform step S2202. However, the flowchart does not necessarily mean that the terminal performs all of the above steps or only the above steps.

In the case of the terminal, the step S2201 may be an operation related to generating the above-described content, for example, DM-RS, and for details, refer to the description of the related part. In addition, the step S2202 may be an operation related to the DM-RS transmission through the above-described contents, for example, the DM-RS resource region, for details, refer to the description of the relevant portion.

In other words, an embodiment of the present invention provides a method for transmitting a demodulation-reference signal (DM-RS) by a first terminal in a wireless communication system, comprising: generating the DM-RS (S2201); And transmitting the generated DM-RS to a second terminal through a DM-RS transmission resource region (S2202). And the DM-RS transmission resource region based on at least one of a speed, a latency related requirement, and a frequency range of at least one of the first terminal and the second terminal. We suggest how this is set up.

The speed of at least one of the first terminal and the second terminal corresponds to an absolute speed or a relative speed, and the absolute speed or the relative speed is an average speed of at least one of the first terminal and the second terminal. The maximum speed, the minimum speed, and the instantaneous speed may be set.

The DM-RS transmission resource region is set to a first DM-RS structure when the speed of at least one of the first terminal and the second terminal is higher than or equal to a threshold, and the first terminal and the second terminal are configured. If the speed of at least one of the terminals is lower than the threshold value may be set to the second DM-RS structure.

The method includes receiving configuration information regarding the DM-RS transmission resource region from a base station through higher layer signaling or physical layer signaling; It may further include.

Receiving the configuration information from the base station comprises: receiving first information indicating a plurality of structures associated with the DM-RS transmission resource region; And receiving second information representing any one of the plurality of structures; It may include.

The DM-RS transmission resource region includes a first DM-RS structure and a second DM-RS structure, wherein the plurality of DM-RSs are arranged in a time division multiplexing (TDM) scheme. In the second DM-RS structure, a plurality of DM-RSs may be arranged in a frequency division multiplexing (FDM) scheme.

In the first DM-RS structure and the second DM-RS structure, the positions where the plurality of DM-RSs are arranged in the resource region are starting positions at which the first DM-RSs are arranged and intervals between the plurality of DM-RSs It may be set based on at least one of the start position and the interval of each of the remaining DM-RS except the first DM-RS in the plurality of DM-RS, and the position of each of the plurality of DM-RS. .

When the DM-RS transmission resource region is set to the first DM-RS structure, among the plurality of DM-RSs, the DM-RS corresponding to each of the plurality of antenna ports is set to be arranged in different frequency regions, and the When the DM-RS transmission resource region is set to the second DM-RS structure, the DM-RS corresponding to each of the plurality of antenna ports may be set to be arranged in different time domains.

23 is a flowchart illustrating the operation of a base station according to the embodiments of the present invention described above. The base station may perform step S2301 and perform step S2302. However, the flowchart does not necessarily mean that the terminal performs all of the above steps or only the above steps.

In the case of a base station, step S2301 may include at least one of the above-described contents, for example, a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal. Based on the above, the operation may be related to setting a demodulation-reference signal (DM-RS) transmission resource region. For details, refer to the description of the related part. In addition, the step S2302 may be an operation related to transmitting the above-described contents, for example, configuration information related to the set DM-RS transmission resource region to the first terminal, and specific contents of the relevant portion See description.

In other words, an embodiment of the present invention provides a method for transmitting configuration information by a base station in a wireless communication system, the speed, latency-related requirements of at least one of the first terminal and the second terminal, and FR Setting a demodulation-reference signal (DM-RS) transmission resource region based on at least one of (Frequency Range) (S2301); And transmitting configuration information related to the set resource region to the first terminal (S2302). Propose a method that includes.

24 is a flowchart illustrating an operation of a terminal associated with the above-described embodiments of the present invention. The terminal may perform step S2401 and perform step S2402. However, the flowchart does not necessarily mean that the terminal performs all of the above steps or only the above steps.

In the case of a terminal, step S2401 may include at least one of the above-described contents, for example, a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal. Based on the above, the operation may be related to setting a demodulation-reference signal (DM-RS) transmission resource region. For details, refer to the description of the related part. In addition, the step S2402 may be an operation related to transmitting the DM-RS to the second terminal through the above-described contents, for example, the configured DM-RS resource region, and detailed description of the relevant portion is described. See.

FIG. 25 is a flowchart illustrating an operation performed between a base station 2501, a first terminal 2502, and a second terminal 2503 according to an exemplary embodiment of the present invention.

25 is a flowchart illustrating an operation of a terminal associated with the above-described embodiments of the present invention. The base station 2501, the first terminal 2502, and / or the second terminal 2503 may perform step S2501, perform step S2502, and perform step S2503. However, the flowchart does not necessarily mean that the terminal performs all of the above steps or only the above steps. Here, the first terminal 2502 may be a Tx UE, and the second terminal 2503 may be an Rx UE or a relay UE.

The base station 2501 is based on at least one of a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal 2502 and the second terminal 2503, and a DM-. An RS (demodulation-reference signal) transmission resource region may be set (S2510).

The base station 2501 may indicate or inform the set DM-RS transmission resource region to the first terminal 2502 (S2520). For example, the base station 2501 may transmit information indicating the set DM-RS transmission resource region to the first terminal 2502. In other words, the first terminal 2502 may receive information indicating the set DM-RS transmission resource region transmitted from the base station 2501. As another example, the first terminal 2502 may obtain information indicating the set DM-RS transmission resource region from the base station 2501 through a physical layer signal or a higher layer signal.

The first terminal 2502 may transmit a DM-RS to the second terminal 2503 through the set DM-RS transmission resource region (S2530). The DM-RS may be generated by the first terminal 2502.

With respect to FIG. 25, for details, refer to the description of the relevant part.

Device configuration according to an embodiment of the present invention

Referring to FIG. 26, a wireless communication system includes a base station (BS) 110 and a terminal (UE) 120. When the wireless communication system includes a relay, the base station or the terminal may be replaced with a relay. In addition, the terminal (UE) 120 may correspond to a Tx UE, an Rx UE, and a Relay UE.

Base station 110 includes a processor 112, a memory 114, and a radio frequency (RF) unit 116. The processor 112 controls the memory 114 and / or the RF unit 116 and may be configured to implement the procedures and / or methods described / proposed above. For example, the processor 112 may process the information in the memory 114 to generate the first information / signal, and then transmit the wireless signal including the first information / signal through the RF unit 116. have. In addition, the processor 112 may receive the radio signal including the second information / signal through the RF unit 116 and then store the information obtained from the signal processing of the second information / signal in the memory 114. have. In one example, processor 112 includes a communication modem designed to implement wireless communication technology (eg, LTE, NR). The memory 114 is connected to the processor 112 and stores various information related to the operation of the processor 112. For example, the memory 114 may store software code that includes instructions for performing some or all of the processes controlled by the processor 112, or for performing the procedures and / or methods described / proposed above. . The RF unit 116 is connected with the processor 112 and transmits and / or receives a radio signal. The RF unit 116 may include a transmitter and / or a receiver. The RF unit 116 may be replaced with a transceiver. Here, the processor 112 and the memory 114 may be part of a processing chip (eg, a System on a Chip, SoC) 111. In a specific example, the processor 112 selects a plurality of resources from two or more frequency resources, and transmits a sidelink signal based on the selected plurality of resources, wherein the processor 112 includes: i) first Setting a demodulation-reference signal (DM-RS) transmission resource region based on at least one of a speed, a latency related requirement, and a frequency range of at least one of the terminal and the second terminal; , ii) configuration information associated with the configured DM-RS transmission resource region may be transmitted to the first terminal.

The processor 112 may be configured to set a demodulation-reference signal (DM-RS) transmission resource region and other configuration information related to the set resource region under conditions other than those described above.

The terminal 120 includes a processor 122, a memory 124, and a radio frequency unit 126. Processor 122 controls memory 124 and / or RF unit 126 and may be configured to implement the procedures and / or methods described / proposed above. For example, the processor 122 may process information in the memory 124 to generate third information / signal, and then transmit the wireless signal including the third information / signal through the RF unit 126. have. In addition, the processor 122 may receive the radio signal including the fourth information / signal through the RF unit 126 and then store information obtained from the signal processing of the fourth information / signal in the memory 124. have. In a specific example, the processor selects a plurality of resources from two or more frequency resources, and transmits a sidelink signal based on the selected plurality of resources, the processor i) generates a DM-RS, and ii ) The generated DM-RS may be transmitted to the second terminal through the DM-RS transmission resource region. The DM-RS transmission resource region may be set based on at least one of a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal. .

Processor 122 includes a communication modem designed to implement wireless communication technology (eg, LTE, NR). The memory 124 is connected with the processor 122 and stores various information related to the operation of the processor 122. For example, the memory 124 may store software code that includes instructions for performing some or all of the processes controlled by the processor 122 or for performing the procedures and / or methods described / proposed above. . The RF unit 126 is connected with the processor 122 and transmits and / or receives a radio signal. RF unit 126 may include a transmitter and / or a receiver. The RF unit 126 may be replaced with a transceiver. Here, the processor 122 and the memory 124 may be part of the processing chip (eg, SoC) 121.

The embodiments described above are the components and features of the present invention are combined in a predetermined form. Each component or feature is to be considered optional unless stated otherwise. Each component or feature may be embodied in a form that is not combined with other components or features. It is also possible to combine some of the components and / or features to form an embodiment of the invention. The order of the operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is obvious that the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship in the claims or as new claims by post-application correction.

In this document, embodiments of the present invention have been described mainly based on a signal transmission / reception relationship between a terminal and a base station. This transmission / reception relationship is extended to the same / similarly for signal transmission / reception between the UE and the relay or the BS and the relay. Certain operations described in this document as being performed by a base station may in some cases be performed by an upper node thereof. That is, it is apparent that various operations performed for communication with the terminal in a network including 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 may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), a gNode B (gNB), an access point, and the like. In addition, the terminal may be replaced with terms such as a user equipment (UE), a mobile station (MS), a mobile subscriber station (MSS), and the like.

Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of a hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), FPGAs ( field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit of the invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

Embodiments of the present invention as described above may be applied to various mobile communication systems.

Claims (11)

1. In a method for transmitting a demodulation-reference signal (DM-RS) by a first terminal in a wireless communication system,

   Generating the DM-RS; And

   Transmitting the generated DM-RS to a second terminal through a DM-RS transmission resource region; Including,

   The DM-RS transmission resource region is set based on at least one of a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal.

   Way.
2. The method of claim 1,

   The speed of at least one of the first terminal and the second terminal corresponds to an absolute speed or a relative speed,

   The absolute speed or the relative speed is set based on any one or more of an average speed, a maximum speed, a minimum speed, and an instantaneous speed of at least one of the first terminal and the second terminal.

   Way.
3. The method of claim 2,

   The DM-RS transmission resource region,

   If the speed of at least one of the first terminal and the second terminal is higher than or equal to the threshold value is set to the first DM-RS structure,

   If the speed of at least one of the first terminal and the second terminal is lower than the threshold is set to the second DM-RS structure

   Way.
4. The method of claim 1,

   Receiving configuration information about the DM-RS transmission resource region from a base station through higher layer signaling or physical layer signaling; Containing more

   Way.
5. The method of claim 4, wherein

   Receiving the configuration information from the base station,

   Receiving first information indicating a plurality of structures associated with the DM-RS transmission resource region; And

   Receiving second information indicative of any of the plurality of structures; Containing

   Way.
6. The method of claim 1,

   The DM-RS transmission resource region includes a first DM-RS structure and a second DM-RS structure.

   In the first DM-RS structure, a plurality of DM-RSs are arranged in a time division multiplexing (TDM) scheme.

   In the second DM-RS structure, a plurality of DM-RSs are arranged in a frequency division multiplexing (FDM) scheme.

   Way.
7. The method of claim 6,

   In the first DM-RS structure and the second DM-RS structure, the positions where the plurality of DM-RSs are arranged in the resource region are starting positions at which the first DM-RSs are arranged and intervals between the plurality of DM-RSs. At least one of the start position and the interval of each of the remaining DM-RSs except the first DM-RS in the plurality of DM-RSs, and at least one of positions of each of the plurality of DM-RSs.

   Way.
8. The method of claim 6,

   When the DM-RS transmission resource region is set to the first DM-RS structure, among the plurality of DM-RSs, the DM-RS corresponding to each of the plurality of antenna ports is set to be arranged in different frequency regions,

   When the DM-RS transmission resource region is set to the second DM-RS structure, the DM-RS corresponding to each of the plurality of antenna ports is set to be arranged in different time domains.

   Way.
9. In the first terminal for transmitting a DM-RS (demodulation-reference signal) in a wireless communication system,

   Transceiver; And

   A processor; Including,

   The processor controls the transceiver to:

   Generate the DM-RS,

   Transmitting the generated DM-RS to a second terminal through the DM-RS transmission resource region;

   The DM-RS transmission resource region is set based on at least one of a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal.

   First terminal.
10. In a method for transmitting configuration information by a base station in a wireless communication system,

    Based on at least one of at least one of a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal, a DM-RS (demodulation-reference signal) transmission resource region Setting up; And

    Transmitting configuration information related to the set resource region to the first terminal;

    Containing

    Way.
11. In the base station for transmitting configuration information in a wireless communication system,

    Transceiver; And

    A processor; Including,

    The processor controls the transceiver to:

    Based on at least one of a speed, a latency related requirement, and a frequency range (FR) of at least one of the first terminal and the second terminal, a DM-RS (demodulation-reference signal) transmission resource region Set it up,

    Transmitting configuration information related to the set resource region to the first terminal

    Base station.

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