KR20200105435A - Method and apparatus for transmitting sounding reference signal - Google Patents

Abstract

The present invention is to provide a sounding reference signal (SRS) transmission method and apparatus for transmitting an SRS capable of preventing collision between a physical uplink shared channel (PUSCH) and the SRS in the case of allowing transmission of the SRS in the same sub-band as the PUSCH. According to an embodiment of the present invention, an operation method of a terminal transmitting an SRS to a base station in a wireless communication system comprises the steps of: receiving a higher layer message including information on a location of an SRS resource for transmission of the SRS from the base station; triggering transmission of the SRS from the base station and receiving a trigger signal including index information of the location of the SRS resource; performing a channel sensing operation on a radio resource indicated by the information on the location of the SRS resource and the index information; and transmitting the SRS to the base station based on the channel sensing result.

Description

Method and apparatus for transmitting sounding reference signals {METHOD AND APPARATUS FOR TRANSMITTING SOUNDING REFERENCE SIGNAL}

The present invention relates to a method of transmitting a sounding reference signal (SRS) in a wireless communication system, and to a method and apparatus for transmitting a sounding reference signal capable of improving channel estimation performance in a base station.

In order to process rapidly increasing radio data, a frequency band higher than the frequency band of LTE (long term evolution) (or LTE-A) (eg, a frequency band of 6 GHz or less) (eg, a frequency band of 6 GHz or higher) A communication system using (for example, a new radio (NR) communication system) is being considered. The NR communication system can support not only a frequency band of 6 GHz or less but also a frequency band of 6 GHz or more, and can support various communication services and scenarios compared to the LTE communication system. For example, the usage scenario of the NR communication system may include enhanced mobile broadband (eMBB), ultra reliable low latency communication (URLLC), and massive machine type communication (mMTC).

In a general wireless communication system, information transmitted from a terminal to a base station is referred to as uplink control information (UCI). Examples of such UCI include a scheduling request, a downlink (DL) channel quality indicator, and an acknowledgment for DL data.

Since a communication system using an unlicensed band supports dynamic time division duplex (TDD), beam-centric communication, or low-delay communication, the number of UL symbols allowing the UE to transmit UCI may be variable and may be limited. .

As an example of a case where the number of UL symbols is variable, the base station may indicate the number of UL symbols to the terminal through higher layer signaling, or the UL to the terminal through a combination of scheduling information and higher layer signaling. It can also indicate the number of symbols.

As an example of a case in which the number of UL symbols is limited, a base station operating in TDD may limit the number of symbols belonging to the UL to a small number for the purpose of more effectively supporting DL traffic in a corresponding slot. Therefore, in a communication system using an unlicensed band, a physical channel for transmitting a sounding reference signal (SRS) can have variable time-dimensional resources and can operate with a small amount of time-dimensional resources. Should be.

In the present invention for solving the above problems, when transmission of a sounding reference signal (SRS) in the same subband as a physical uplink shared channel (PUSCH) is allowed, collision of the PUSCH and the SRS is prevented. It is a technical problem to provide a method and apparatus for transmitting a sounding reference signal that can be prevented.

In the operating method of a terminal for transmitting a sounding reference signal (SRS) to a base station in a wireless communication system according to an embodiment of the present invention to achieve the above object, the location of the SRS resource for transmission of the SRS from the base station Receiving a higher layer message including information; Triggering transmission of the SRS from the base station, and receiving a trigger signal including index information of the location of the SRS resource; Performing a channel sensing operation on a radio resource indicated by information on the location of the SRS resource and the index information; And transmitting an SRS to the base station based on the channel sensing result.

Here, the SRS resource includes at least one SRS transmission slot(s) determined based on a channel sensing result of the radio resource, and the at least one SRS transmission slot(s) is at least one SRS symbol (S) may be included.

Here, the first symbol constituting the SRS may be an arbitrary OFDM (orthogonal frequency division multiplexing) symbol included in the SRS transmission slot(s).

Here, the trigger signal is a candidate of the SRS transmission slot(s) among a plurality of slots, an offset between the SRS transmission slot(s), and symbol(s) included in each of the SRS transmission slot(s) At least one of the candidates of the first SRS symbol(s) may be indicated.

Here, the step of transmitting the SRS to the base station is characterized in that the SRS is transmitted through symbol #n of a slot in which a transmission opportunity is acquired as a result of the channel sensing, and prior to transmitting the radio resource, an initial signal It may further include the step of transmitting (initial signal).

Here, the initial signal may be generated based on a cyclic prefix (CP) of one of a first symbol, an nth symbol, and an n+1th symbol constituting the SRS.

Here, the SRS may be mapped in connection with a physical uplink control channel (PUCCH) and/or a physical uplink shared channel (PUSCH) included in the radio resource.

In order to achieve the above object, a method of operating a base station receiving a sounding reference signal (SRS) in a wireless communication system according to another embodiment of the present invention, comprising: setting a location of an SRS resource for reception of the SRS; Transmitting a higher layer message including information on the location of the SRS resource to the terminal; Triggering transmission of the SRS of the terminal, generating a trigger signal including index information of the location of the SRS resource, and transmitting the trigger signal to the terminal; It may include the step of receiving an SRS from the terminal.

Here, the SRS resource may include at least one or more SRS transmission slot(s), and the at least one or more SRS transmission slot(s) may include at least one or more SRS symbol(s).

Here, the first symbol constituting the SRS may be an arbitrary OFDM (orthogonal frequency division multiplexing) symbol of each of the SRS transmission slot(s).

Here, the trigger signal is a candidate of the SRS transmission slot(s) among a plurality of slots, an offset between the SRS transmission slot(s), and the symbols included in each of the SRS transmission slot(s). It may be characterized by indicating at least one of a candidate of the SRS symbol(s) and an offset between the SRS symbol(s).

Here, the trigger signal may further indicate a first SRS symbol among the SRS symbol(s).

Here, the SRS may be mapped in connection with a physical uplink control channel (PUCCH) and/or a physical uplink shared channel (PUSCH) included in the message.

A terminal for transmitting a sounding reference signal (SRS) to a base station in a wireless communication system according to another embodiment of the present invention for achieving the above object, comprising: a processor; And a memory in which at least one command executed through the processor is stored, wherein the at least one command includes a higher layer message including information on a location of an SRS resource for transmission of the SRS from the base station. Receive; Triggering the transmission of the SRS from the base station, and receiving a trigger signal including index information of the location of the SRS resource; Sensing a channel of a radio resource based on the information on the location of the SRS resource and the index information; It may be executed to transmit an SRS to the base station based on the channel sensing result.

Here, the SRS resource includes at least one SRS transmission slot(s) determined based on a channel sensing result of the radio resource, and the at least one SRS transmission slot(s) is at least one SRS symbol (S) may be included.

Here, the first symbol constituting the SRS symbol(s) may be an arbitrary OFDM (orthogonal frequency division multiplexing) symbol of each of the SRS transmission slot(s).

Here, the at least one command is, in sensing the channel of the radio resource, by sensing a channel from the first SRS symbol indicated by the trigger signal among the SRS symbol(s) at an offset interval indicated by the trigger signal , Can be implemented to obtain a transmission opportunity.

Here, the at least one command is characterized in that when transmitting the SRS to the base station, the SRS is transmitted through symbol #n, which is the first SRS symbol among SRS symbols that have obtained a transmission opportunity as a result of the channel sensing. And, prior to transmitting the SRS, it may be further executed to transmit an initial signal.

Here, the initial signal may be generated based on a cyclic prefix (CP) of one of a first symbol, an nth symbol, and an n+1th symbol constituting the SRS.

Here, the SRS may be mapped in connection with a physical uplink control channel (PUCCH) and/or a physical uplink shared channel (PUSCH) included in the radio resource.

According to the present invention, the base station allows transmission of a sounding reference signal (SRS) through an interlace structure and a comb structure of the same subband as a physical uplink shared channel (PUSCH). Thus, it is possible to prevent a collision between the PUSCH and the SRS.

According to the present invention, the terminal can improve the channel estimation performance of the base station by transmitting the sounding reference signal over a broadband.

1 is a conceptual diagram showing a first embodiment of a communication system.
2 is a block diagram showing a first embodiment of a communication node constituting a communication system.
3 is a flowchart illustrating an embodiment of a method for transmitting a sounding reference signal (SRS) of the present invention.
4 is a conceptual diagram showing a first embodiment of the SRS resource of the present invention.
5 is a conceptual diagram showing a second embodiment of the SRS resource of the present invention.
6 is a conceptual diagram showing a third embodiment of the SRS resource of the present invention.
7 is a conceptual diagram illustrating an embodiment of an active bandwidth part (BWP) of a radio resource and a listen before talk (LBT) subband.
8 is a conceptual diagram illustrating a first embodiment of an SRS mapping method for SRS resources.
9 is a conceptual diagram illustrating a second embodiment of an SRS mapping method for SRS resources.
10 is a conceptual diagram illustrating a third embodiment of an SRS mapping method for SRS resources.
11 is a conceptual diagram illustrating an embodiment of frequency resources occupied by SRS resources.
12 is a conceptual diagram illustrating an embodiment of a time resource occupied by an SRS resource.
13 is a conceptual diagram illustrating a first embodiment of an uplink channel and SRS resource allocation.
14 is a conceptual diagram illustrating a second embodiment of an uplink channel and SRS resource allocation.
15 is a conceptual diagram illustrating a third embodiment of an uplink channel and SRS resource allocation.
16 is a conceptual diagram illustrating a first embodiment of an SRS resource configuration including at least one symbol.
17 is a conceptual diagram illustrating a second embodiment of an SRS resource configuration including at least one symbol.
18 is a conceptual diagram illustrating a third embodiment of an SRS resource configuration including at least one symbol.
19 is a conceptual diagram illustrating a fourth embodiment of an SRS resource configuration including at least one symbol.
20 is a conceptual diagram illustrating a first embodiment of a contention window size (CWS) and an N value set in each LBT (listen before talk) subband.
21 is a conceptual diagram showing a second embodiment of CWS and N values set in each LBT subband.
22 is a conceptual diagram showing a third embodiment of CWS and N values set in each LBT subband.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it is to be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it is understood that it may be directly connected or connected to the other component, but other components may exist in the middle. Should be. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, in order to facilitate an overall understanding, the same reference numerals are used for the same elements in the drawings, and duplicate descriptions for the same elements are omitted.

Throughout the specification, a terminal is a mobile station (MS), a mobile terminal (MT), an advanced mobile station (AMS), a high reliability mobile station (HR-MS). ), subscriber station (SS), portable subscriber station (PSS), access terminal (AT), user equipment (terminal), machine type communication device, MTC device) or the like, and may include all or part of functions such as MT, MS, AMS, HR-MS, SS, PSS, AT, UE, and the like.

In addition, the base station (BS) is an advanced base station (ABS), a high reliability base station (HR-BS), a node B (node B), an advanced node B (evolved node B), eNodeB), access point (AP), radio access station (RAS), base transceiver station (BTS), mobile multihop relay (MMR)-BS, relay serving as a base station station, RS), a relay node (RN) that acts as a base station, an advanced relay station (ARS) that acts as a base station, and a high reliability relay station (HR) that acts as a base station. -RS), small base station (femto BS), home node B (home node B, HNB), home eNodeB (HeNB), pico base station (pico BS), macro base station (macro BS), micro base station (micro BS) ), etc.], etc., and may include all or part of functions such as ABS, NodeB, eNodeB, AP, RAS, BTS, MMR-BS, RS, RN, ARS, HR-RS, small base stations, etc. have.

The base station configures one or several cells, and the terminal establishes an RRC connection with at least one cell of the corresponding base station. Here, a cell with an RRC connection is referred to as a serving cell.

1 is a conceptual diagram showing a first embodiment of a communication system.

Referring to FIG. 1, a communication system 100 includes a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Here, the communication system 100 may be referred to as a “communication network”. Each of the plurality of communication nodes may support at least one communication protocol. For example, each of the plurality of communication nodes is a communication protocol based on code division multiple access (CDMA), a communication protocol based on wideband CDMA (WCDMA), a communication protocol based on time division multiple access (TDMA), and frequency division multiple access (FDMA). access) based communication protocol, OFDM (orthogonal frequency division multiplexing) based communication protocol, OFDMA (orthogonal frequency division multiple access) based communication protocol, SC (single carrier)-FDMA based communication protocol, NOMA (non-orthogonal multiple) access)-based communication protocol, space division multiple access (SDMA)-based communication protocol, etc. may be supported. Each of the plurality of communication nodes may have the following structure.

2 is a block diagram showing a first embodiment of a communication node constituting a communication system.

Referring to FIG. 2, the communication node 200 may include at least one processor 210, a memory 220, and a transmission/reception device 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240, an output interface device 250, and a storage device 260. Each of the components included in the communication node 200 may be connected by a bus 270 to perform communication with each other.

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260. The processor 210 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may be configured with at least one of a volatile storage medium and a nonvolatile storage medium. For example, the memory 220 may be formed of at least one of a read only memory (ROM) and a random access memory (RAM).

Referring back to FIG. 1, the communication system 100 includes a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and a plurality of user equipment. ) (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong within the coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong within the coverage of the third base station 110-3. . The first terminal 130-1 may belong within the coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong within the coverage of the fifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 is a NodeB, an evolved NodeB, a base transceiver station (BTS), Radio base station, radio transceiver, access point, access node, road side unit (RSU), radio remote head (RRH), transmission point (TP) , May be referred to as a transmission and reception point (TRP), a relay node, and the like. Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5 and 130-6 is a terminal, an access terminal, a mobile terminal, Station (station), subscriber station (subscriber station), mobile station (mobile station), portable subscriber station (portable subscriber station), node (node), may be referred to as a device (device).

A plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) Each of them may support cellular communication (eg, long term evolution (LTE), LTE-A (advanced), etc. specified in the 3rd generation partnership project (3GPP) standard). Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in a different frequency band or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other through an ideal backhaul or a non-ideal backhaul, and the ideal backhaul Alternatively, information can be exchanged with each other through non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to a core network (not shown) through an ideal backhaul or a non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to the corresponding terminal 130-1, 130-2, 130-3, 130 -4, 130-5, 130-6), and the signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) Can be transferred to.

Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can support OFDMA-based downlink transmission, and SC-FDMA-based uplink ) Can support transmission. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits multiple input multiple output (MIMO) (eg, single user (SU)-MIMO, Multi-user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation transmission, transmission in an unlicensed band, device to device, D2D ) Communication (or ProSe (proximity services)), etc. may be supported. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 is a base station 110-1, 110-2, 110-3, 120-1 , 120-2) and operations supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be performed.

For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 based on the SU-MIMO scheme, and the fourth terminal 130-4 can transmit a signal to the fourth terminal 130-4 by the SU-MIMO scheme. A signal may be received from the second base station 110-2. Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 based on the MU-MIMO method, and the fourth terminal 130-4 And each of the fifth terminal 130-5 may receive a signal from the second base station 110-2 by the MU-MIMO method. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, and The terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by the CoMP method. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 has terminals 130-1, 130-2, 130-3, 130-4, and 130-5, 130-6) and a carrier aggregation method can transmit and receive signals. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 coordinate D2D communication between the fourth terminal 130-4 and the fifth terminal 130-5 (coordination), and each of the fourth terminal 130-4 and the fifth terminal 130-5 is D2D communication by coordination of the second base station 110-2 and the third base station 110-3 Can be done.

3 is a flowchart illustrating an embodiment of a method for transmitting a sounding reference signal (SRS) of the present invention.

Referring to FIG. 3, the base station may derive the location (frequency resource location and time resource location) of the SRS resource for transmission of a sounding reference signal (SRS) (S310). The time resource location information may be composed of one or more UL (uplink) sub-slots, and the corresponding UL subslot may be located in the middle of the last symbol or UL slot. Here, the base station transmits the SRS using values such as a transmission comb (TC) value, a bandwidth configuration variable, a bandwidth variable, a frequency hopping bandwidth variable, and frequency domain position information. It is possible to derive a frequency resource location for.

The base station may indicate the SRS resource location to the terminal. That is, the base station may transmit information on the resource location for transmission of the SRS to the terminal. The base station may transmit information on the location of at least one SRS resource for transmission of the SRS to the terminal by using higher layer signaling. The base station may transmit configuration information of some of the information for configuring the SRS resource to the terminal (S320). In addition, the base station may transmit the remaining configuration information not transmitted through higher layer signaling among the information for configuring the SRS resource to the terminal through a trigger signal (S330).

The base station may transmit the SRS resource index, which is information for configuring the SRS resource, to the terminal through higher layer signaling (S320). The SRS resource index may include information on frequency resources, sequence information, and antenna port information, and the SRS resource index may be set for each SRS resource in the form of a preset list.

In a wireless communication network using an unlicensed band, a time resource for transmitting an SRS may have a dynamic property according to a listen before talk (LBT) procedure. Accordingly, information on time resources for transmitting the SRS may be included in the trigger signal. The base station may transmit a trigger signal to the UE through some fields of a downlink control information (DCI) field for allocating a physical downlink shared channel (PDSCH) in a downlink (DL) control channel or a DCI field for allocating a PUSCH ( S330). Alternatively, the base station may instruct a plurality of terminals through a specific DCI format preset to trigger SRS transmission of the terminal. The base station may indicate to the terminal time resources for transmitting the SRS through higher layer signaling in the form of an index.

The terminal may obtain information on the location of the SRS resource from the upper layer signaling and DL control channel received from the base station (S340). The UE may derive candidate resources of an SRS resource element (RE) from the index of the trigger signal. The terminal may determine a time resource to transmit the SRS according to channel sensing (eg, LBT procedure) in the radio resource indicated by the information on the location of the SRS resource of the upper layer signaling and the index information of the trigger signal. . The terminal may perform the LBT operation even at a time earlier than the start time of the radio resource indicated by the higher layer signaling and trigger signal. The terminal may map the SRS to the SRS resource element based on the channel sensing result of the radio resource indicated by the information on the SRS resource location (S350). The UE may map the SRS in the order of time resources, and then map the SRS in the order of frequency resources. As another example, the UE may map the SRS in the order of frequency resources, and then map the SRS in the order of time resources.

The UE may map the SRS to at least one SRS resource element and transmit a subframe including at least one or more resource elements to the base station (S360). Therefore, the terminal can transmit the SRS to the base station (S360). The specific configuration of the SRS resource may be as described below.

The base station performing wireless communication in the unlicensed band may set resources for transmitting the SRS through higher layer signaling. The base station may transmit an index indicating the SRS resource to the terminal through the DL control channel. The DL control channel may include a trigger field for triggering SRS transmission of the terminal and a time field indicating information on the transmission time of the SRS. The trigger field may indicate the index of SRS resources to be allocated to the terminal. The time field may indicate the first resource (eg, subframe, slot, symbol, etc.) of the SRS resource to be allocated to the UE. Alternatively, in the DL control channel, only one field may be included without distinguishing between a trigger field and a time field. This field is represented by an index set by higher layer signaling, and can indicate time resources and frequency resources for transmitting SRS transmission as one index.

The SRS resource may include at least one comb (comb, for example, 2 subcarriers or 4 subcarrier intervals) arranged at regular subcarrier intervals. On the other hand, the PUSCH resource may include at least one interlace arranged at regular physical resource block (PRB) intervals. Therefore, the SRS resource may perform time division multiplexing (TDM) in the same symbol as the PUSCH, but may not be able to frequency division multiplexing (FDM). Therefore, in some subcarriers, the SRS may overlap with the PUSCH, but in other subcarriers, the SRS may not overlap with the PUSCH.

4 is a conceptual diagram showing a first embodiment of the SRS resource of the present invention.

Referring to FIG. 4, the SRS resource according to an embodiment of the present invention may include at least one interlace arranged at regular physical resource block (PRB) intervals. The base station may transmit information on the SRS resource including at least one interlace to the terminal through higher layer signaling.

The terminal may receive higher layer signaling and DL control channel from the base station. The UE may map the SRS to an SRS resource element belonging to a preset interlace. The SRS resource element and the PUSCH may be arranged in PRBs belonging to different interlaces. Accordingly, the UE may map the SRS and PUSCH to different interlaces in an FDM scheme.

5 is a conceptual diagram showing a second embodiment of the SRS resource of the present invention.

Referring to FIG. 5, each interlace of the SRS resource according to another embodiment of the present invention may include at least one comb arranged at a predetermined subcarrier interval. The base station may transmit information on the SRS resource including at least one interlace and at least one comb to the terminal through higher layer signaling.

The terminal may receive higher layer signaling and DL control channel from the base station. The UE may map the SRS to each comb included in the interlace. The UE may map the SRS and PUSCH to the same interlace. However, when the SRS resource element occupies a subcarrier different from the PUSCH within the same interlace, the SRS may be mapped in the PUSCH and FDM scheme. When the DM-RS symbol and the data symbol are TDM, and the DM-RS symbol is located before the data symbol, the PUSCH may have a certain interval in the subcarrier unit within the interlace. If the PUSCH is composed of two symbols, the DM-RS resource can be FDM in the same symbol as the data, and if the PUSCH is more than two symbols (for example, 4 or 7 or more) When configured, the DM-RS resource may be mapped on symbols different from the data.

6 is a conceptual diagram showing a third embodiment of the SRS resource of the present invention.

Referring to FIG. 6, SRS resource elements according to another embodiment of the present invention may be mapped to PUSCH and code division multiplexing (CDM). The PUSCH may include a demodulation reference signal (DM-RS) resource of the PUSCH, which is a resource for a reference signal for demodulation of the PUSCH, and a PUSCH data resource, which is a resource for transmitting uplink data. The SRS resource elements and the DM-RS resource elements of the PUSCH may be distributed discretely, and the SRS resource elements may be mapped with the DM-RS resource elements of the PUSCH in a CDM manner.

A terminal performing wireless communication in an unlicensed band may perform an LBT procedure, and may transmit a signal according to the result of the LBT procedure. That is, the UE transmitting the SRS in the unlicensed band may perform the LBT procedure prior to transmitting the SRS. In addition, the UE transmitting the PUSCH in the unlicensed band may perform the LBT procedure prior to transmitting the PUSCH. Accordingly, the UE can transmit the SRS through resources allocated to the PUSCH. In particular, the UE may transmit the SRS through the same resource as the resource allocated to the DM-RS of the PUSCH. A symbol including resources allocated to the PUSCH DM-RS may be located first among the symbols of the PUSCH. Specifically, the UE may map the SRS resource element and the DM-RS resource element of the PUSCH to the symbol in a CDM scheme.

According to an embodiment of the present invention, the UE may generate SRS resource elements as a complex vector having a constant length of a ZC sequence (Zadoff-Chu sequence), and map SRS resource elements to resources having an interlace structure and a comb structure. can do.

When the PUSCH DM-RS resource element is generated based on the ZC sequence, the interlace structure and the comb structure of the resource to which the SRS resource elements are mapped may be the same as the structure of the resource to which the DM-RS resource element of the PUSCH is mapped. In order to use the constant amplitude zero auto correlation waveform (CAZAC), which is a property of the ZC sequence, the SRS resource element may be generated from the same basis sequence as the PUSCH DM-RS resource element. In addition, the SRS resource element may have a cyclic shift different from that of the PUSCH DM-RS resource element. Each terminal may generate an SRS and a PUSCH DM-RS using the same ZC sequence and different cyclic shift information. Each UE may map the generated SRS and PUSCH DM-RS in a CDM scheme. Each terminal can transmit the generated signal to the base station. The base station may classify the simultaneously received signals (PUSCH DM-RS and SRS) based on cyclic shift information.

It may be difficult for a terminal performing communication in an unlicensed band to know exactly when the SRS is transmitted. If the sequence hopping and cyclic shift information of the ZC sequence depends on the time information of the SRS resource, the terminal may generate a plurality of SRSs respectively according to the result of the LBT procedure, and as a result, the signal processing time and the amount of computation of the terminal Can increase. Therefore, the base station transmits the sequence hopping (eg, group hopping, sequence shift, sequence hopping, etc.) information and/or cyclic shift information of the ZC sequence to information about time resources for transmitting the SRS (ie, slot index or symbol). Can be set irrespective of the index of.

Moreover, according to the prior art, the base station generates a pattern of SRS resources through the ZC sequence in all bands of the BWP included in the common resource grid, and then only the PRBs corresponding to the active BWP are associated with the ZC sequence. A sequence may not be mapped to a resource. In addition, the terminals may generate a ZC sequence only for the PRB corresponding to the required bandwidth and map it to the SRS resource. Therefore, if the positions of the PRBs to be actually used for transmission are shifted from each other, multiplexing (eg, CDM-based multiplexing) of ZC sequences may be impossible.

According to another embodiment of the present invention, the UE may generate the SRS as a complex vector having a constant length of the PN sequence. The UE may generate an SRS to have an interlace structure and/or a comb structure.

When the PUSCH DM-RS is generated based on the PN sequence, the interlace structure and the comb structure of the PUSCH DM-RS resource and the SRS resource may be the same. The terminal may further apply an orthogonal cover code (OCC) to the PN sequence to generate the PUSCH DM-RS. When the UE further applies OCC to the PN sequence to generate the PUSCH DM-RS, the UE may generate the SRS based on the PN sequence. And the terminal may generate the SRS by additionally applying the OCC.

According to the conventional technology, the terminal can obtain scrambling information from the base station through higher layer signaling, and can initialize the PN sequence using the scrambling information. The terminal may or may not receive at least one or more scrambling information from the base station. For example, the UE may generate a PUSCH DM-RS from a PN sequence according to a conventional technical standard (eg, TS 38.211). In addition, the UE may generate the PUSCH DM-RS by additionally applying OCC to the PN sequence according to the CDM group.

According to an embodiment of the present invention, the SRS resource may have a comb structure, and the number k of combs may be 2 or 4. In order to maintain a similar frequency response of a channel, the UE may generate an SRS by applying OCC in PRB units in an interlace belonging to one or more symbols.

The UE may generate an SRS by applying an OCC having a length of h=12/k (ie, h=6 when k=2, h=3 when k=4) in one PRB. In the case of applying the OCC, the UE may generate an SRS by applying the same PN sequence value to the same OCC. Therefore, the length of the PN sequence may be the same as the number of PRBs belonging to the interlace.

)의 지수들로 구성될 수 있다. 표 1은 h=6 인 경우의 DFT 시퀀스(

)를 예시할 수 있으며, 표 2는 h=3 인 경우의 DFT 시퀀스(

)를 예시할 수 있다. The OCC may be one of non-orthogonal sequences such as a Hadamard sequence or a discrete Fourier transform (DFT) sequence. According to an embodiment of the present invention, when the value of h is not an exponent of 2, the UE may apply the OCC by applying the DFT sequence. The DFT sequence is h-th root of unity (

) Can be composed of indices. Table 1 shows the DFT sequence when h=6 (

) Can be illustrated, and Table 2 shows the DFT sequence in the case of h=3 (

) Can be illustrated.

이 성립하는

들을 선택할 수 있다. 단말에 의해 선택된 열 벡터들은 서로 직교하는 성질을 가질 수 있다. 그리고 단말에 의해 선택된 열 벡터들은 q-th root of unity에 따른 일정한 복소수의 사이클릭 시프트 간격을 가질 수 있다. 따라서, 단말은 주파수 선택적인 무선 채널에서도 OCC 인덱스를 적용하여 SRS를 생성할 수 있다. The UE may generate an SRS by applying some (eg, q, q<h) OCC indexes of h OCC indexes. In order to select q number of OCC indexes, the terminal is selected from Tables 1 to 2

This constitutes

You can choose. The column vectors selected by the terminal may have a property that is orthogonal to each other. In addition, the column vectors selected by the terminal may have a constant complex number of cyclic shift intervals according to the q-th root of unity. Accordingly, the terminal can generate the SRS by applying the OCC index even in the frequency selective radio channel.

The base station may transmit scrambling information for initializing the sequence to the terminals. The terminal may initialize the PN sequence using the scrambling information received from the base station. The terminal may generate the SRS by applying the initialized PN sequence. If,

In addition, a separate terminal may initialize the PN sequence using the scrambling information received from the base station. A separate terminal may receive the same scrambling information from the base station. The UE may generate a PUSCH DM-RS by applying the initialized PN sequence.

It may be difficult for a terminal performing communication in an unlicensed band to accurately secure the transmission time of the SRS. Therefore, when the scrambling information of the PN sequence is set depending on the time resource (eg, slot or symbol) of the SRS, the terminal may perform an LBT procedure for each of a plurality of SRS symbols. In addition, the terminal can generate the SRS according to the LBT result for each SRS symbol, so that the processing time and the computation amount of the terminal can be increased. Accordingly, according to an embodiment of the present invention, the scrambling information of the PN sequence may be set irrespective of the information of the time resource occupied by the SRS resource element (ie, the slot index or the symbol index).

And the base station can transmit the OCC information to the terminal. The base station may transmit different OCC information to different terminals. Terminals may receive the same scrambling information from the base station, and may receive different OCC information. The terminals may generate different signals (eg, PUSCH DM-RS or SRS) based on the received scrambling information and OCC information. Therefore, the SRS can be CDM with the PUSCH DM-RS. Each of the terminals may transmit a channel including the generated signal (eg, PUSCH DM-RS or SRS) to the base station. The base station may receive a channel including a PUSCH DM-RS and an SRS from terminals. The base station may obtain the PUSCH DM-RS and/or SRS by classifying the received sequences.

Some bands of the BWPs occupied by the terminals may overlap each other. That is, on an overlapped band (ie, LBT subband(s)), SRS resources may be multiplexed with each other. In addition, each of the SRS resources may be configured in the same interlace and comb form. Lengths of sequences for generating SRS resources may be different from each other, and each SRS resource may be mapped in a CDM method.

7 is a conceptual diagram illustrating an embodiment of an active bandwidth (BWP) and LBT subband of a radio resource.

Referring to FIG. 7, SRS resources may be multiplexed on radio resources. Terminals can occupy active BWPs including different bandwidths. The bandwidth of the active BWP may be an integer multiple of the bandwidth of the LBT subband. The terminal may perform an LBT procedure for each LBT subband. Therefore, the bandwidth of the band for transmitting the SRS may be an integer multiple of the bandwidth of the LBT subband. The BWP of the LBT subband occupied by each terminal may have a different center frequency.

According to an embodiment of the present invention, the terminal may separately generate the SRS as a unit corresponding to the LBT subband. When the UE secures a frequency resource corresponding to one LBT subband using the LBT procedure, the UE may generate an SRS sequence having a length corresponding to the secured LBT subband. The UE may map the SRS sequence generated based on a reference point (eg, reference point A) of the LBT subband to the common resource grid.

When the UE secures frequency resources corresponding to two or more LBT subbands by using the LBT procedure, the UE may generate SRS sequences having a length corresponding to each of the secured LBT subbands. The UE may map SRS sequences generated based on a reference point (eg, reference point A) for each LBT subband to a common resource grid.

Each of the LBT subbands can be arranged consecutively. Consecutive LBT subbands may include contiguous PRBs. Specifically, when the UE secures only one LBT subband and transmits the SRS by the LBT procedure, the LBT subband is the PRBs to which the SRS is mapped, and PRBs that do not (ie, PRBs belonging to the boundary of the LBT subbands). ) Can be separated. The boundary of the LBT subband may be composed of PRBs corresponding to a predetermined number. The UE may not map the SRS to PRBs included in the boundary of the LBT subband according to the result of performing the LBT procedure. However, when the UE secures two adjacent LBT subbands, the UE may map the SRS to PRBs included in the boundary of the LBT subband.

The base station may set the BWP to the terminal through higher layer signaling. However, if the bandwidth of the BWP is at least twice or more than the LBT subband, the base station may indicate the boundary of the LBT subband to the UE in units of PRB. For the active BWP, the terminal may use the LBT subband(s) according to the result of the LBT procedure performed before UL transmission. The base station may indicate to the terminal the boundary of the LBT subbands for each BWP (band part) through higher layer signaling. In transmitting the SRS or PUSCH, the UE may transmit a UL signal and/or a channel using PRBs belonging to the boundaries of LBT subbands.

A terminal according to another embodiment of the present invention includes PRBs constituting a boundary from an LBT subband having a lower center frequency among two LBT subbands constituting the boundary, and a reference point of the corresponding LBT subband (e.g., A sequence can be mapped from the reference point A) to the bordered PRB. Accordingly, the UE can map a relatively long sequence to an LBT subband having a relatively low center frequency among the two LBT subbands, and map a relatively short sequence to an LBT subband having a relatively high center frequency. have. The difference in length of each sequence may be derived based on information on the number of PRBs forming the boundary.

SRS mapping method for SRS resources

Embodiments of SRS mapping for SRS resources may be as described below. The SRS resource may include one interlace or some combs or transmission combs included in one interlace. The UE may sequentially map the SRS to the subcarriers. However, since the SRS resource may be composed of two or more interlaces, a mapping method that can be applied regardless of the number of interlaces is required.

8 is a conceptual diagram illustrating a first embodiment of an SRS mapping method for SRS resources.

Referring to FIG. 8, a UE according to an embodiment of the present invention may sequentially map SRSs to subcarriers. That is, even if the SRS symbol includes multiple interlaces, the UE may map the SRS in the order of subcarriers of the SRS resource. The UE may alternately map the SRS to different interlaces. Therefore, the SRS of the terminal may not be multiplexed (eg, CDM) with a signal (eg, PUSCH DM-RS) of another terminal using only one interlace. When the same sequence is not mapped in a common interlace, different signals (eg, SRS or PUSCH DM-RS) received by the base station may not be distinguished.

9 is a conceptual diagram illustrating a second embodiment of an SRS mapping method for SRS resources.

Referring to FIG. 9, priorities between interlaces may be set for a plurality of interlaces included in an SRS resource according to another embodiment of the present invention. The UE may map the SRS to the SRS resource based on priority information of a plurality of interlaces. For example, the UE may preferentially map the SRS to subcarriers belonging to the high priority interlace, and may additionally map the SRS to subcarriers belonging to the lower priority interlace.

10 is a conceptual diagram illustrating a third embodiment of an SRS mapping method for SRS resources.

Referring to FIG. 10, different terminals according to another embodiment of the present invention may acquire resources (eg, SRS resources) including different numbers of interlaces, respectively. Each terminal may initialize a sequence for each interlace. Each of the terminals may map resource elements generated based on the same sequence in a common interlace to a resource. Each of the terminals may transmit a message including the SRS to the base station. The base station can receive a message including the SRS from the terminals, and the base station can distinguish between different SRSs received from different terminals.

Frequency resource for SRS transmission

The terminal may obtain information on at least one or more LBT subbands from the base station. The terminal may perform an LBT operation on the acquired at least one LBT subband. The UE may map the SRS to the SRS resource of the LBT subband that succeeds in LBT among at least one LBT subband. The terminal may transmit the SRS mapped to the SRS resource (eg, interlace or comb) to the base station.

When the SRS resource includes two or more symbols, the UE may perform an LBT procedure for each symbol. If the LBT fails in some LBT subband(s) included in one symbol and the SRS cannot be transmitted, the UE may perform the LBT procedure for the next symbol. As a result of the LBT operation, if the UE can use the LBT subband(s) that were not accessible in the previous symbol, the UE may increase the LBT subband(s) used in the corresponding symbol. Therefore, the bandwidth of the SRS symbol transmitted in the n+1th symbol may be greater than or equal to the bandwidth of the SRS symbol transmitted in the nth symbol (n=0, 1, ...). When the UE maps the SRS in adjacent LBT subbands, the UE may map the SRS to a PRB belonging to a guard band.

SRS transmission method through frequency hopping

11 is a conceptual diagram illustrating an embodiment of frequency resources occupied by SRS resources.

Referring to FIG. 11, subcarriers of the SRS resource may be configured in a comb structure included in the entire band. The SRS is instructed to transmit in a narrow band, and when the base station triggers, the position of the band in which the SRS is transmitted may be changed by an index (or SRS counter) possessed by the terminal. When the base station triggers the SRS transmission of the terminal at least one or more times, the SRS may be transmitted at least one or more times through all locations on the band. Accordingly, the base station can know all the frequency response values of the BWP of the terminal. However, in the unlicensed band, since the SRS resource is not defined as a narrow band, but is defined in an interlace unit, and satisfies the frequency regulation by using a frequency resource corresponding to a broadband, it may be difficult to apply the conventional method as it is.

According to an embodiment of the present invention, the UE may map the SRS to radio resources by hopping in an interlace unit. When the subcarrier spacing in which the SRS is transmitted is 15 kHz, one LBT subband may include 10 interlaces. Therefore, the base station can set one SRS resource to the terminal, and can trigger the SRS over 10 times. The UE may transmit the SRS through a different interlace each time, and thus the base station may estimate a channel based on all interlaces belonging to the LBT subband. Since the SRS resource may occupy not only interlace but also comb-type frequency resources, the base station may not be able to estimate channels of all subcarriers belonging to the LBT subband. The UE may map the SRS by hopping the interlace of the SRS resource, and may not map the SRS by hopping the comb. Since combs adjacent to each other may be divided into at least one or more subcarriers (eg, two or four), the comb may be set to be smaller than the correlation bandwidth of the channel.

Time resource for SRS transmission

12 is a conceptual diagram illustrating an embodiment of a time resource occupied by an SRS resource.

Referring to FIG. 12, SRS resources may be mapped in the last symbol(s) of a subframe or slot. However, in the unlicensed band, since the terminal transmits the SRS according to the LBT operation result, after the terminals compete on the UL resource, only one terminal transmits the UL signal and/or channel through the UL resource, or multiple terminals They can transmit UL signals and/or channels through FDM or CDM. Therefore, the SRS can be PUSCH and FDM or CDM. In addition, the first symbol belonging to the SRS resource may be the same symbol as the first symbol belonging to the PUSCH. In addition, the first symbol of the PUSCH may include a DM-RS resource, and thus the SRS may be mapped to the start symbol of the PUSCH. The first symbol of the PUSCH may be an arbitrary symbol that is not limited to the first or last symbol of the slot, and thus the first symbol of the SRS resource may be any symbol of the slot.

In order to transmit the SRS, the terminal may perform an LBT procedure. When transmitting the SRS through a time resource (channel occupancy time (COT)) allocated from the base station, the terminal may perform a short LBT (eg, category 2 LBT). On the other hand, when the terminal transmits the SRS through a time resource (eg, COT) secured by itself, the terminal may perform a long LBT (eg, category 3 or 4 LBT). Since the SRS symbol index(s) of the SRS resource located within the subframe or slot can be fixed, the base station only starts the first subframe or slot in the form of an index in order to transmit the information on the SRS resource. The triggering DL control channel can be transmitted.

The PUSCH may occupy a time resource of a shorter unit (eg, a mini slot or a sub slot) than a subframe or slot. Therefore, the terminal can transmit the SRS through the SRS resource only when the symbol index of the SRS resource is further acquired.

The base station may transmit the DCI including the trigger signal to the terminal. The trigger signal may include index information indicating the location of the SRS resource. Index information of the trigger signal may indicate a time resource for SRS transmission. Specifically, the index information of the SRS resource may include all resources (eg, time, frequency, sequence, precoding information, pre-processing information, etc.) for transmitting the SRS. The trigger signal indicates only the index of the SRS resource, and sufficient information can be delivered. Therefore, the capacity of the trigger signal can be reduced. On the other hand, since all resources of the SRS resource are set as indexes, the capacity of higher layer signaling (eg, RRC message) can be increased.

The terminal may receive a trigger signal from the base station. The terminal may acquire information on time resources for transmitting the SRS from the received trigger signal. The terminal may perform the LBT procedure from the time indicated by the trigger signal. The terminal may transmit the SRS through the first time resource among the resources that succeed in LBT.

When the SRS resource includes two or more symbols, the first symbol of the SRS resource may be any symbol belonging to the slot. Therefore, according to the result of the LBT procedure, the last symbol of the SRS resource may belong to a different slot than the first symbol of the SRS resource. When one SRS resource is transmitted through multiple slots, scheduling and interference environments for serving base stations of each of the multiple slots may be different from each other. Therefore, it may be desirable that one SRS resource belongs to only one slot. Therefore, when transmitting the SRS resource, the UE transmits from the first symbol belonging to the SRS resource, but may skip a transmission procedure without transmitting a symbol beyond the boundary of the corresponding slot.

The terminal may receive a trigger signal through the n-th slot. In addition, the terminal may sequentially perform the LBT procedure from n+u slots after the slot offset (u). The UE may transmit the SRS by performing the LBT procedure on the earliest symbol (ie, symbol t1 in slot n+u) among candidate symbols belonging to n+u slots. If the LBT procedure is not successful in all candidate symbols belonging to the n+u slot (eg, all symbols belonging to the slot), the UE may not transmit the SRS through the corresponding slot. In one embodiment, the terminal may no longer transmit the SRS. In another embodiment, the terminal may perform the same operation in a subsequent slot (ie, slot n+u+1).

According to an embodiment, higher layer signaling may indicate a slot offset for transmitting the SRS. According to another embodiment, higher layer signaling may indicate a slot offset for transmitting the SRS and a symbol index or a first symbol t1 transmitted by the SRS resource. If higher layer signaling does not separately indicate the first symbol transmitted by the SRS resource, the UE may perform the LBT procedure from the first symbol (ie, t1 = 0) of slot n+u to transmit the SRS. .

In the case of the NR system, the base station may transmit a trigger signal to a plurality of unspecified terminals in DCI format 2_3. In addition, each of a plurality of unspecified terminals may check information on a slot for transmitting an SRS according to higher layer signaling. Since the location indicated by is known, each of the terminals may obtain an SRS trigger index based on the format 2_3 information of the DCI. The UE may derive the SRS transmission slot based on the slot offset (u) information, and may perform the LBT procedure from the first symbol of the derived slot. According to an embodiment of the present invention, the index of the trigger signal is It is possible to indicate a slot offset and/or a candidate of symbols (t1, t2, t3, ..., tT). The index of the trigger signal may indicate information on the coded slot offset and/or candidates for symbols. For example, the slot offset and the number of slots may be indicated to the UE using one index, and candidates of symbols may be set to the UE through higher layer signaling.

Although only one candidate set may be known to the UE, when several candidate sets are known to the UE, the UE may obtain candidate set information indicated by the index of the trigger signal. According to another embodiment, candidates for symbols may be indicated by higher layer signaling, and the slot offset may be indicated by a trigger signal.

The terminal may receive a trigger signal through the n-th slot. In addition, the terminal may sequentially perform the LBT procedure on the candidate symbols included in the n+u slot after the slot offset (u). The UE may transmit the SRS through the symbol of the earliest time point that has passed the LBT procedure among candidate symbols (ie, symbol t1 in slot n+u). If the LBT procedure is not passed in all candidate symbols belonging to the n+u slot (ie, symbols t1, t2, .., tT in slot n+u), the UE may not transmit the SRS through the corresponding slot. .

According to another embodiment of the present invention, the index of the trigger signal may indicate a slot offset (u) and/or a symbol offset (t). The index of the trigger signal may indicate coded slot offset information and symbol offset information. For example, the slot offset and the number of slots may be indicated to the terminal using one index. According to an embodiment, candidates for symbols may be indicated through an index of a trigger signal and a separate indicator. According to another embodiment, the index of the trigger signal may indicate both the slot offset, the number of slots, and the symbol offset. Alternatively, the slot offset and the number of slots are indicated by a trigger signal, and the symbol offset may be set by higher layer signaling. According to another embodiment, the symbol offset may be indicated by higher layer signaling, and the slot offset may be indicated by a trigger signal.

The UE may sequentially perform the LBT procedure and transmit the SRS to see if the SRS can be transmitted at symbol t in the slot (n+u) generated after the slot offset (u) from the slot (n) receiving the trigger signal. According to an embodiment of the present invention, if the LBT procedure is not passed in the corresponding candidate symbol belonging to the corresponding slot, the terminal may not transmit the SRS. The UE may attempt the LBT procedure in the next slot (n+u+1). According to an embodiment of the present invention, the UE may attempt the LBT procedure in candidate symbols (ie, symbols t1, t2, .., tT) belonging to a corresponding slot (ie, slot n+u), and a subsequent LBT procedure. SRS may not be transmitted in the slot.

According to another embodiment of the present invention, the index of a trigger signal may indicate a candidate (n1, n2, ..., nw) of slots and/or a symbol offset (t).

The candidate set of slots and symbol offset information may be simultaneously encoded and included in the trigger signal in the form of an index. For example, if only one candidate set of slots is set to the UE as a higher layer, it is not necessary to indicate to the UE including this in the trigger signal. It may be included in the trigger signal so that this single candidate set can be recognized. The symbol offset is indicated to the terminal as slot candidates and index, so that the terminal can derive all slot candidates and symbol offset from one index. Alternatively, the slot candidate set information may be indicated by a trigger signal, and the symbol offset information may be indicated by higher layer signaling.

The UE performs the LBT procedure in order to see if the SRS can be transmitted from the symbol (i.e., symbol t) to which the symbol offset is applied in the slot (i.e. slot n1) occurring after the slot (n) in which the trigger signal is received. Can be transmitted. If the LBT procedure is not passed in the corresponding candidate symbol belonging to the corresponding slot, the SRS may not be transmitted. If the UE fails all of the LBT procedure in symbols included in the corresponding slot, the LBT procedure may be performed from the first symbol (ie, symbol t) included in the next slot (ie, slot n2). If the UE fails the LBT procedure even at the last position (ie, symbol t) of symbol candidates in slot nw, it does not transmit the SRS.

According to another embodiment of the present invention, the index of the trigger signal may indicate a candidate of slots (n1, n2, ..., nw) and/or a candidate of symbols (t1, t2, t3, ..., tT). I can.

Here, some of these information may be simultaneously encoded and included in the trigger signal in the form of an index. For example, a candidate set of slots may be indicated to the terminal using one index, and a candidate set of symbols may be set to the terminal through higher layer signaling. Alternatively, one index may indicate not only a candidate set of slots but also a candidate set of symbols to the terminal.

The UE performs the LBT procedure in order to see if it can transmit the SRS from the symbol candidate (i.e., symbol t1) in the slot (i.e., slot n1) occurring after the trigger signal is received from the slot (n) and can transmit the SRS. have. If the LBT procedure does not pass in the corresponding candidate symbol belonging to the corresponding slot, the terminal may determine whether the SRS can be transmitted by performing the LBT procedure in the next symbol (ie, symbol t2). If the UE fails all of the LBT procedure in the symbols included in the corresponding slot, the LBT procedure may be performed from the first candidate symbol (ie, symbol t1) included in the next slot (ie, slot n2). If the UE fails the LBT procedure even at the last position (ie, symbol tT) of symbol candidates in slot nw, it may not transmit the SRS.

Configuration in which SRS and PUSCH/PUCCH are TDM

The base station may trigger the SRS transmission of the terminal by transmitting the DCI including the trigger signal. The DCI may be a DL-DCI for allocating a PDSCH or a UL-DCI for allocating a PUSCH. The SRS may be transmitted through a PUSCH or a physical uplink control channel (PUCCH) and different resources (eg, symbols, etc.).

13 is a conceptual diagram illustrating a first embodiment of an uplink channel and SRS resource allocation.

Referring to FIG. 13, the base station may trigger the SRS transmission by the UE through DCI (ie, DL-DCI or UL-DCI). When transmission of the SRS is triggered by DCI, the DCI may include information on the SRS resource and the UL channel (ie, PUSCH and/or PUCCH) resource. The SRS resource and the UL channel resource may be temporally contiguous.

DCI may include information on the start symbol of the SRS resource. In addition, the DCI may include information on the start symbol of the UL channel resource. When the SRS resource and the UL channel resource are not concatenated with each other, the base station may indicate the start symbol of each resource (eg, SRS resource, PUSCH and/or PUCCH) through different fields of DCI. When the SRS resource is arranged in connection with the UL channel resource, the base station may indicate to the terminal only the SRS resource or the start symbol of the UL channel resource through DCI. The base station may transmit a DCI including information on the SRS resource to the terminal. The DCI allocating the UL channel may further indicate the category of the LBT procedure as well as the start time resource of the UL channel. The UE may derive the UL channel start time resource and the category of the LBT procedure based on the index set by higher layer signaling. For example, in the case of an NR system, a specific field of DCI may indicate an index value, and an index indicated by DCI may indicate a type of LBT procedure and an extension length of a cyclic prefix (CP). The extension length of the CP may be one of four values. For example, the index indicated by DCI is 0 (i.e., does not extend the CP to be applied to the UL channel), a value minus 25us from the length of C1 symbols, and (16 us+TA) from the length of C2 symbols One of a value obtained by subtracting (timing advance)) and a value obtained by subtracting (25 us+TA) from the length of C3 symbols may be indicated. The value of C1 indicated by the index may be a value determined according to the interval of subcarriers of the UL channel, and the values of C2 and C3 may be values given to the terminal through higher layer signaling. The UE may extend and transmit the CP of the first symbol constituting the UL channel by a value indicated by the index. The terminal can receive the DCI from the base station. The UE may obtain information on each resource (eg, SRS resource, PUCCH and/or PUSCH resource) from the received DCI. The terminal may map resource elements to each resource based on the acquired resource information. The terminal may transmit a message including the SRS and/or PUCCH/PUSCH to the base station.

Meanwhile, when two or more PUSCHs are allocated, a configuration in which TDM is performed between PUSCHs may be proposed. However, the transmission power of the SRS and the transmission power of the PUSCH may be different from each other. Accordingly, PUSCH and SRS may be mapped to each other in a TDM manner, and PUSCHs may be sequentially arranged.

According to an embodiment of the present invention, the UE may transmit the PUSCH and/or PUCCH after transmitting the SRS. The base station may transmit the DCI including information on the start symbol of the SRS resource to the terminal. The terminal receiving the DCI from the base station may obtain information on the start symbol of the SRS resource. In the case of the PUSCH, the start and length indicator value (SLIV) of the PUSCH must be generated so that the PUSCH is allocated following the last symbol of the SRS resource. In the case of PUCCH, the resource index of the PUCCH must be generated so that the PUCCH is allocated following the last symbol of the SRS resource.

Alternatively, the UE may know the start symbol of the PUSCH and/or PUCCH from the SLIV of the PUSCH (or the resource index of the PUCCH). Accordingly, the UE may map the SRS to resources previously allocated as many as the number of symbols of the SRS resource.

If the SRS resource is allocated prior to the PUSCH/PUCCH resource, the UE may not be able to transmit the SRS by the LBT procedure. When the SRS resource is disposed prior to the PUSCH/PUCCH resource, the SRS transmission probability of the UE may be relatively low, and the PUSCH/PUCCH transmission probability may be relatively high compared to the SRS transmission probability. Accordingly, when the priority of the PUSCH/PUCCH is higher than the priority of the SRS transmission, the UE may increase the transmission probability of the PUSCH/PUCCH by preferentially placing the SRS on the radio resource. If one UL-DCI indicates a plurality of PUSCH resources, the SRS resource may be allocated prior to the plurality of PUSCH resources.

14 is a conceptual diagram illustrating a second embodiment of an uplink channel and SRS resource allocation.

Referring to FIG. 14, a UE according to another embodiment of the present invention may transmit an SRS after transmitting a PUSCH and/or PUCCH. The UE may map the SRS to a resource contiguous with the last symbol of the PUSCH resource indicated by SLIV of the PUSCH. The base station may not indicate the location of the start symbol of the SRS resource to the terminal through UL-DCI.

The base station can receive the SRS from the terminal. The base station may estimate the UL channel with the terminal based on the SRS received from the terminals. In addition, the base station may determine the coding rate and modulation rate of the PUSCH using the estimated UL channel. Therefore, the later the UE transmits the SRS, the less the change in the UL channel due to fading may be. According to the configuration in which the SRS resource is allocated after the PUSCH resource, the base station can relatively more accurately estimate the response of the UL channel with the terminal. However, according to the LBT procedure, the probability of transmitting the PUSCH may be relatively lower than the probability of transmitting the SRS. Therefore, it may be desirable for the base station to secure the quality of the UL-SCH (i.e., quality of service (QoS)) previously deployed through the retransmission procedure. When one UL-DCI allocates a plurality of PUSCH resources, the SRS resource may be allocated after the plurality of PUSCH resources.

Depending on the result of the LBT procedure, the UE may not be able to transmit the UL channel (ie, PUSCH and/or PUCCH). If the UE fails to transmit the UL channel, the UE may perform the LBT procedure in the next symbol of the last symbol configuring the UL channel. According to an embodiment, when the terminal fails to transmit the SRS through the time resource instructed to transmit the SRS resource as a result of performing the LBT procedure, the terminal may not transmit the SRS. According to another embodiment, as a result of the UE performing the LBT procedure, even if the SRS cannot be transmitted through the time resource instructed to transmit the SRS resource, the UE may perform the LBT procedure again in the next symbol. The UE may repeat the LBT procedure in the remaining symbols belonging to the same slot, and the UE may transmit the SRS from the first symbol that passes the LBT procedure.

According to an embodiment, when the UE fails to transmit the UL channel by the LBT procedure, the UE may apply the extended length of the CP applied to the UL channel to the SRS resource as it is. That is, the terminal may apply the extended length of the CP indicated by the DCI in the first symbol constituting the SRS resource. According to another embodiment, when the UE fails to transmit the UL channel by the LBT procedure, the UE may apply the extension length of the CP applied to the UL channel to each symbol belonging to the SRS resource as it is. That is, the UE may apply the extended length of the CP indicated by DCI in the first symbol transmitted by the LBT procedure among symbols belonging to the SRS resource.

15 is a conceptual diagram illustrating a third embodiment of an uplink channel and SRS resource allocation.

Referring to FIG. 15, the SRS resource of the PUSCH according to another embodiment of the present invention may be differently allocated on the resource of the PUCCH and the radio resource.

The base station may transmit DL-DCI and/or UL-DCI to the terminal. The UE may receive DL-DCI and/or UL-DCI from the base station. The UE may divide and multiplex a time resource to map an SRS resource triggered by DL-DCI and a time resource to map an SRS resource triggered by UL-DCI. According to another embodiment of the present invention, the SRS resource of the PUSCH may be allocated after the PUSCH, and the SRS resource of the PUCCH may be allocated before the PUCCH. Or, conversely, the SRS resource of the PUSCH may be allocated before the PUSCH, and the SRS resource of the PUCCH may be allocated after the PUCCH.

According to the characteristics of the LBT procedure, there may be a low probability that a resource disposed earlier in time is transmitted to the base station, and a resource disposed later may have a relatively high probability of being transmitted to the base station. In addition, considering the fading of the UL channel, the response of the UL channel estimated by the base station may be accurate when it is placed back in time. Therefore, the communication node (eg, the base station and/or the terminal) may pre-set the priority between the PUCCH and the SRS, and may pre-set the priority between the PUSCH and the SRS.

For example, PUCCH may have a higher priority than SRS. The reason is that if the PUCCH cannot be transmitted, the base station must perform the LBT procedure to retransmit the DL-DCI and the PDSCH, and the terminal must also perform the LBT procedure to transmit the PUCCH. However, since the SRS resource can trigger only the SRS resource even in the DL-DCI or UL-DCI, the radio resources occupied by the base station or the terminal may be less. Also, the SRS is a reference signal for estimating the UL channel and may not be used to transmit or retransmit DL data. In addition, a sufficiently low coding rate and modulation rate may be applied to the PUCCH to be robustly transmitted even in the fading of the UL channel. Therefore, in order to further increase the transmission probability of the PUCCH, the SRS resource may be allocated prior to the PUCCH resource.

For example, the PUSCH may have a lower priority than the SRS resource. In order to retransmit the PUSCH, the base station may dynamically determine a coding rate and a modulation rate based on the fading of the UL channel. Therefore, in order to accurately measure the UL channel of the base station, the SRS resource may be allocated to the rear end of the PUSCH.

Time resource when two or more symbols constitute one SRS resource

16 is a conceptual diagram illustrating a first embodiment of an SRS resource configuration including at least one symbol.

Referring to FIG. 16, one SRS resource may include at least one or more SRS symbols. When the terminal uses a plurality of antenna ports to transmit the SRS, the terminal may transmit one SRS symbol through one antenna port. The UE may acquire SRS resources from consecutive symbols as many as the number of SRS antenna ports. The terminal may acquire at least one contiguous and arranged SRS resource for beam management. When the number of antennas of the terminal is different from the number of SRS antenna ports of the SRS resource, the terminal can transmit the SRS using at least one or more symbols through the antenna switching scheme. When the UE additionally performs the LBT procedure in the unlicensed band, the time resource of the SRS resource including at least one symbol may be expressed in a resource unit, and in detail, may be expressed in a symbol unit.

According to an embodiment of the present invention, when the UE passes the LBT procedure in the first symbol of the SRS resource, the UE may map the SRS to the time resource that has passed the LBT procedure and transmit it to the base station.

The UE may transmit the SRS through the first symbol of the SRS resource in order to transmit the SRS by being semi-fixedly allocated, periodically or triggered by DCI. Even if the SRS resource is composed of two or more SRS symbols, the terminal may obtain time resource information for SRS transmission based on the DCI received from the base station. The UE may map the SRS to a resource indicated by the acquired time resource information.

When the base station indicates a plurality of time resources, the terminal may perform an LBT procedure for each time resource. As a result of performing the LBT procedure, the terminal may transmit the SRS through a time resource that can be transmitted first among each of the time resources. The UE may transmit all symbols constituting the SRS or may not transmit all symbols, and thus, channel tracking is possible only at some antenna ports, so-called imbalance between antenna ports may not occur. In addition, the LBT procedure of the terminal for transmitting the PUSCH may be the same as the LBT procedure for transmitting the SRS of the terminal.

According to an embodiment of the present invention, the terminal may attempt the LBT procedure in the next time resource in order to transmit the SRS. According to the LBT procedure, the UE may transmit all symbols constituting the SRS or may not transmit all symbols. If the LBT procedure is not successful in the first symbol constituting the SRS resource, the UE may retry the LBT procedure in the next allowed time resource. The allowed time resource may be a specific symbol index (eg, the index of the first symbol of the SRS resource) in the next slot, or may be the first symbol of the next slot.

17 is a conceptual diagram illustrating a second embodiment of an SRS resource configuration including at least one symbol.

Referring to FIG. 17, a terminal according to an embodiment of the present invention may transmit an initial signal through a first symbol of an SRS determined to be transmitted. The UE may perform the LBT procedure by applying CWS and N in the LBT subband(s) to be used to transmit the SRS. The channel acquisition time point of the terminal may precede the first symbol of the SRS by T (eg, tens of ns). If the time point at which the channel is acquired precedes the time point at which the first symbol of the SRS is transmitted, the terminal may transmit the initial signal by T or less than T.

If the terminal does not transmit any signal during T, another communication node (eg, the terminal or the base station) may transmit the signal. Therefore, the UE may not be able to transmit the SRS due to signal transmission from another communication node. Accordingly, the terminal transmits an initial signal at a time when a transmission opportunity is acquired, thereby preventing other communication nodes from occupying resources. The initial signal for the SRS can be obtained from the first symbol constituting the SRS.

According to an embodiment of the present invention, the terminal may generate an initial signal by extending the first symbol constituting the SRS.

If the LBT succeeds before the time point at which the UE should transmit the SRS, the UE may generate an initial signal by extending the CP of the first symbol constituting the SRS as necessary. The length of the initial signal may be included and indicated in a trigger signal indicated to the terminal from the serving base station. The length of the initial signal is indicated as 0, or a preset time having an integer number of units of the symbol or a constant offset from the preset time (length of time used in the LBT procedure (e.g., 25 us, 16 us) and TA ( timing advance), etc.). Alternatively, the CP length may be expressed as an index set by higher layer signaling or an index indicated in a technical standard. Due to the characteristics of the initial signal, the serving base station can secure orthogonality between signals of terminals. The length of the initial signal (eg, the length of the CP, the number of symbols, etc.) may be indicated by the interval of the subcarriers of the BWP or may be indicated by higher layer signaling.

The terminal may transmit the generated initial signal to the base station. The terminal may be the entire time interval (T) from the time point at which the LBT is successful to the time point of the first symbol, or may mean only a part of the time interval. Even when the CP of the first symbol constituting the SRS is extended, a conventional process of generating an OFDM symbol can be applied as it is. The reason is that more of the OFDM samples can be simply placed in front. When the base station receives the SRS symbol and applies the DFT interval, the terminal may use the remaining OFDM samples excluding the extended OFDM samples and the OFDM samples of the CP. In transmitting not only the SRS but also the PUSCH and PUCCH, the UE may generate an initial signal and then transmit each channel.

18 is a conceptual diagram illustrating a third embodiment of an SRS resource configuration including at least one symbol.

Referring to FIG. 18, among symbols constituting the SRS resource according to an embodiment of the present invention, the SRS may be transmitted from a time resource for the first SRS transmission that has passed the LBT procedure. Unlike PUSCH, the SRS can function for each symbol. In the process of decoding the PUSCH, the base station may decode the PUSCH using all symbols. The base station may measure the quality of different radio links by using each symbol constituting the SRS. The terminal may be assigned at least one PUSCH mapped in the type B scheme, and may transmit from the PUSCH mapped in the type B scheme that first passed the LBT procedure. The UE may transmit from a symbol that first passes the LBT procedure among PUSCHs mapped to type A. In this case, the terminal may puncture a symbol (or RE) that has not been transmitted for the encoded TB (or codeword), and transmit a portion of the codeword mapped to the first symbol that succeeds in the LBT procedure.

In order to transmit several symbols constituting the SRS, the UE may perform the LBT procedure for each time resource for SRS transmission. Prior to transmitting the SRS, it may be assumed that the sequentially transmitted SRS can continue to use LBT subbands. Therefore, the LBT procedure may no longer be performed in the LBT subband secured by the terminal by using the LBT procedure. However, the UE may perform the LBT procedure immediately before transmitting the SRS symbol for the LBT subband that has not been secured.

According to an embodiment of the present invention, when the terminal fails the LBT operation in all slots constituting the SRS resource, the terminal may perform the LBT procedure again in the next slot. The index of the symbol constituting the SRS resource in the next slot may be maintained the same as the previous slot.

According to another embodiment of the present invention, when the terminal fails the LBT operation in all slots constituting the SRS resource, the terminal may no longer transmit the SRS. The base station may transmit a new trigger signal to the terminal. The UE that fails the LBT operation may retransmit the SRS after receiving a new trigger signal from the base station.

19 is a conceptual diagram illustrating a fourth embodiment of an SRS resource configuration including at least one symbol.

Referring to FIG. 19, a terminal according to an embodiment of the present invention may transmit an initial signal for a first symbol determined to transmit an SRS. The terminal may succeed in the LBT procedure prior to transmitting the SRS symbol for several tens of ns. The UE may perform UL transmission from a symbol located after the symbol that succeeds in the LBT procedure. In order to prevent the occupancy of resources by other communication nodes (eg, base station or terminal), the terminal may transmit an initial signal. The terminal may generate an initial signal based on the generated SRS symbol.

When the LBT procedure is successful in the transfer of the first symbol of the SRS resource, the UE may use an extended CP (extended CP) of the first symbol constituting the SRS as an initial signal. The length of the initial signal may be included and indicated in a trigger signal indicated to the terminal from the serving base station. The length of the initial signal is indicated as 0, or a preset time having an integer number of units of the symbol or a constant offset from the preset time (length of time used in the LBT procedure (e.g., 25 us, 16 us) and TA ( timing advance), etc.). Alternatively, the CP length may be expressed as an index set by higher layer signaling or an index indicated in a technical standard. Due to the characteristics of the initial signal, the serving base station can secure orthogonality between signals of terminals. The length of the initial signal (e.g., the length of the CP, the number of symbols, etc.) may be indicated by the interval of the subcarriers of the BWP, or may be indicated by higher layer signaling. If the LBT procedure is successful immediately before transmitting the LBT, the following method can be applied. For convenience of explanation, the time when the LBT procedure is successful may be assumed to be between symbol n and symbol n+1 (n=0,1,2,...). Before transmitting the first symbol of the SRS, the terminal can secure a time of about tens of ns by the LBT procedure. And after the second or more symbols of the SRS, the terminal can secure a time of about several tens of us by the LBT procedure.

As a result of performing the LBT procedure, the terminal may not be able to transmit the SRS symbol n to the base station. Accordingly, according to an embodiment of the present invention, the terminal may utilize the extended CP of the n+1 th symbol constituting the SRS transmitted after the time resource after the LBT procedure is successful as an initial signal.

According to another embodiment of the present invention, the terminal may configure the initial signal using the nth symbol constituting the SRS corresponding to the time resource that the LBT procedure was successful. Since the time resource that succeeded in the LBT procedure is a section in which symbol n constituting the SRS needs to be transmitted, the UE can use an OFDM symbol derived from symbol n constituting the SRS. The OFDM symbol of the SRS symbol n can be used from the time resource at which the UE succeeds in the LBT procedure to the start point of the symbol n+1 (and CP for it) constituting the SRS. The base station may not be able to detect an accurate UL transmission start time of the terminal. The base station may detect energy and determine whether the UE transmits a UL signal and/or a channel. The base station may DFT the received UL signal and/or channel to distinguish between an OFDM symbol determined to be mapped to a signal on an OFDM symbol basis and an OFDM symbol to which the signal is not mapped. The base station may estimate the UL channel using only the OFDM symbols to which the signal is mapped (ie, using only a part of the SRS symbol n).

The UE may secure phase continuity while transmitting part of the SRS symbol n and all of the SRS symbol n+1. When the terminal starts to transmit the SRS symbol n, the PAPR of the power amplifier may increase instantaneously. In addition, when the terminal transmits the SRS symbol n+1, the PAPR of the power amplifier is stabilized and may be the same as the PAPR at the time when all SRS symbols are transmitted.

Channel access method of a terminal transmitting UL resource elements (eg, SRS resource elements, PUSCH) through a bandwidth portion (BWP) spanning two or more LBT sub-bandwidths

For channel access, also referred to as category 4 LBT (C4LBT), the terminal can manage the contention window size (CWS) according to a predetermined rule. The terminal may select an arbitrary number smaller than the CWS, and may set the selected number as a counter N. When the active BWP occupies two or more LBT subbands, the UE can manage the CWS and counter values maintained for UL transmission for each LBT subband (ie, CWS1, N1, CWS2, N2, etc.). CWS is defined one by one according to the channel access priority class (CAPC) of the LBT subband, and this is expressed as per p for convenience of explanation. Alternatively, the terminal may manage the CWS and counter values as one value irrelevant to the LBT subband.

20 is a conceptual diagram showing a first embodiment of CWS and N values set in each LBT subband.

Referring to FIG. 20, an active BWP according to an embodiment of the present invention may have a unique counter value N for each LBT subband (A1). When each LBT subband has a unique N, the terminal can manage the CWS for each LBT subband. Accordingly, both CWS and N may be set differently for each LBT subband. The UE may select one N to perform UL transmission. Specifically, the terminal may select one N of a plurality of Ns (eg, a counter value N of an LBT subband serving as a reference). The terminal may select the largest N among N values of the LBT subbands.

On the other hand, by managing one CWS in the active BWP, it is possible to consider a method in which several LBT subbands share one CWS. CWS can be set to one, and thus N can also be defined as one value.

21 is a conceptual diagram showing a second embodiment of CWS and N values set in each LBT subband.

Referring to FIG. 21, a terminal according to an embodiment of the present invention may manage one counter value N irrespective of the bandwidth of the active BWP (A2). The CWS for setting the counter value N may be expressed as a function of the CWS of LBT subbands belonging to the active BWP. For the CAPC of the traffic to be transmitted, the terminal may select one LBT subband among LBT subbands. For example, the terminal may select an LBT subband having the largest CWS or the smallest CWS among CWSs of the LBT subbands. The counter value N can be set based on the CWS of the selected LBT subband.

In order for the UE to perform UL transmission, one counter value N may be set, and each LBT subband may have a CWS. If the UE fails to transmit the UL channel in some LBT subbands or if the UE transmits PUSCH but the base station fails to decode, the UE may update the CWS of the LBT subband.

When the active BWP includes a plurality of LBT subbands, the UE may manage a separate CWS for application to the LBT subband to which UL transmission is allocated or the LBT subband used for UL transmission in updating the CWS. .

According to an embodiment of the present invention, the terminal may manage CWS for each LBT subband (with one N value). When the terminal receives the NACK for the PUSCH from the base station (e.g., when the NDI toggles in the same HPID or receives the NACK as a DFI (Downlink Feedback Indicator)), the terminal is active by reflecting the NACK CWS can be updated in all LBT subbands belonging to the BWP.

When the UE fails to transmit UL in some LBT subbands, the UE may consider that it has not performed UL transmission through some LBT subbands. Accordingly, the UE can update only the CWS of the LBT subband that succeeds in UL transmission and/or fails.

When the base station instructs the UL grant to use only some LBT subbands among active BWPs, the UE may use CWSs of some LBT subbands according to the indicated UL grant. The UE may select one LBT subband from among LBT subbands. For example, the terminal may select an LBT subband having the largest CWS or the smallest CWS among CWSs of the LBT subbands. The terminal may set the counter N based on the CWS of the selected LBT subband.

22 is a conceptual diagram showing a third embodiment of CWS and N values set in each LBT subband.

Referring to FIG. 22, a terminal according to an embodiment of the present invention may manage one CWS in an active BWP. Accordingly, at least one or more LBT subbands may share one CWS (with one N value).

The terminal can transmit only one UL signal and/or channel in the BWP. Accordingly, the UE may select one CWS as a reference or define only one CWS without managing CWS for each of the LBT subbands in at least one LBT subband (per p).

When the UE fails to transmit UL in some LBT subbands, the UE may update the CWS in consideration of the number of failed LBT subbands. The terminal can manage one CWS. Therefore, when the terminal updates the CWS due to the failed LBT subband, the terminal can apply the updated CWS to the LBT subband that succeeds in LBT (for all p).

When the UE is assigned a PUSCH in N LBT subbands and transmits a PUSCH through M (<N) LBT subbands, the UE may retransmit the PUSCH. The base station can instruct the terminal to a UL grant with the same HPID without the toggle of NDI. The terminal may increase the size of the CWS. According to the conventional method, since it is limited in the case of N=1, the size of CWS may increase by 1 or the maximum value (eg, CWSp,max) may be maintained.

According to an embodiment of the present invention, the size of CWS may be given as a function of M. According to an embodiment, as the CWS is updated, the size of the CWS may increase by M. Alternatively, as the CWS is updated, the size of the CWS may have a maximum value (per p). That is, when CWS is updated, the size of CWS may be updated to a smaller value among CWSp+M, CWSp, and max.

According to another embodiment, as the terminal updates the CWS, the size of the CWS may increase by M/N. Alternatively, as the CWS is updated, the size of the CWS may have a maximum value (per p). That is, when the CWS is updated, the size of the CWS may be updated to a smaller value among CWSp + M/N, CWSp, and max.

The methods according to the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the computer-readable medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software.

Examples of computer-readable media include hardware devices specially configured to store and execute program instructions, such as rom, ram, flash memory, and the like. Examples of program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The above-described hardware device may be configured to operate as at least one software module to perform the operation of the present invention, and vice versa.

Although described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention described in the following claims. I will be able to.

Claims (20)

In the operating method of a terminal transmitting a sounding reference signal (SRS) to a base station in a wireless communication system,
Receiving a higher layer message including information on a location of an SRS resource for transmission of the SRS from the base station;
Triggering transmission of the SRS from the base station, and receiving a trigger signal including index information of the location of the SRS resource;
Performing a channel sensing operation on a radio resource indicated by information on the location of the SRS resource and the index information; And
And transmitting an SRS to the base station based on the channel sensing result. In claim 1,
The SRS resource,
Including at least one or more SRS transmission slot(s) determined based on a channel sensing result of the radio resource,
The at least one or more SRS transmission slot(s),
Including at least one or more SRS symbol (s), the operating method of the terminal. In claim 2,
The first symbol constituting the SRS is
A method of operating a terminal which is an arbitrary OFDM (orthogonal frequency division multiplexing) symbol included in the SRS transmission slot(s). In claim 2,
The trigger signal is,
A candidate of the SRS transmission slot(s) among a plurality of slots, an offset between the SRS transmission slot(s), and the first SRS symbol(s) among symbol(s) included in each of the SRS transmission slot(s) Method of operating a terminal, characterized in that indicating at least one of the candidates of. In claim 1,
Transmitting the SRS to the base station,
The SRS is transmitted through symbol #n of a slot in which a transmission opportunity is acquired as a result of the channel sensing,
Prior to transmitting the radio resource, the method of operating a terminal further comprising transmitting an initial signal. According to claim 5,
The initial signal is,
A method of operating a terminal, characterized in that it is generated based on a cyclic prefix (CP) of one of a first symbol, an nth symbol, and an n+1th symbol constituting the SRS. In claim 1,
The SRS is,
A method of operating a terminal, characterized in that mapping is performed in connection with a physical uplink control channel (PUCCH) and/or a physical uplink shared channel (PUSCH) included in the radio resource. In a method of operating a base station receiving a sounding reference signal (SRS) in a wireless communication system,
Setting a location of an SRS resource for receiving the SRS;
Transmitting a higher layer message including information on the location of the SRS resource to the terminal;
Triggering transmission of the SRS of the terminal, generating a trigger signal including index information of the location of the SRS resource, and transmitting the trigger signal to the terminal;
Operating method of a base station comprising the step of receiving an SRS from the terminal. According to claim 8,
The SRS resource includes at least one or more SRS transmission slot(s),
The at least one or more SRS transmission slot(s) includes at least one or more SRS symbol(s). According to claim 9,
The first symbol constituting the SRS is,
The operation method of the base station, characterized in that the random OFDM (orthogonal frequency division multiplexing) symbol of each of the SRS transmission slot(s). According to claim 9,
The trigger signal is a candidate of the SRS transmission slot(s) among a plurality of slots, an offset between the SRS transmission slot(s), and the SRS symbol among symbols included in each of the SRS transmission slot(s) The operation method of the base station, characterized in that indicating at least one of the offset between the candidate (s) and the SRS symbol (s). According to claim 11,
The trigger signal is,
A method of operating a base station, characterized in that further indicating a first SRS symbol among the SRS symbol(s). According to claim 8,
The SRS is,
The operation method of a base station, characterized in that the mapping in connection with the PUCCH (physical uplink control channel) and / or PUSCH (physical uplink shared channel) included in the message. In a terminal transmitting an SRS (sounding reference signal) to a base station in a wireless communication system,
Processor; And
Includes a memory (memory) in which at least one instruction executed through the processor is stored,
The at least one command,
Receiving a higher layer message including information on a location of an SRS resource for transmission of the SRS from the base station;
Triggering the transmission of the SRS from the base station, and receiving a trigger signal including index information of the location of the SRS resource;
Sensing a channel of a radio resource based on the information on the location of the SRS resource and the index information;
Terminal executed to transmit an SRS to the base station based on the channel sensing result. The method according to claim 14,
The SRS resource,
Including at least one or more SRS transmission slot(s) determined based on a channel sensing result of the radio resource,
The at least one or more SRS transmission slot(s),
Terminal comprising at least one or more SRS symbol(s). The method according to claim 15,
The first symbol constituting the SRS symbol(s) is,
The terminal, characterized in that the random OFDM (orthogonal frequency division multiplexing) symbol of each of the SRS transmission slot(s). The method according to claim 15,
The at least one command,
In sensing the channel of the radio resource,
A terminal executed to acquire a transmission opportunity by sensing a channel at an offset interval indicated by the trigger signal from the first SRS symbol indicated by the trigger signal among the SRS symbol(s). The method of claim 17,
The at least one command,
In transmitting the SRS to the base station,
The SRS is transmitted through symbol #n, which is a first SRS symbol among SRS symbols that have acquired a transmission opportunity as a result of the channel sensing,
Prior to transmitting the SRS, the terminal is further executed to transmit an initial signal. The method of claim 18,
The initial signal is,
A terminal, characterized in that it is generated based on a cyclic prefix (CP) of one of a first symbol, an nth symbol, and an n+1th symbol constituting the SRS. The method according to claim 14,
The SRS is,
A UE, characterized in that the UE is mapped in connection with a physical uplink control channel (PUCCH) and/or a physical uplink shared channel (PUSCH) included in the radio resource.

Images