KR20200112680A - Method and apparatus for transmitting and receiving signal in communication system supporting unlicensed band - Google Patents

Abstract

Disclosed are a method and apparatus for transmitting and receiving signals in a communication system supporting an unlicensed band. According to the present invention, an operation method of a terminal comprises the steps of: acquiring a time period for occupying a channel by performing a listen before talk (LBT) operation; transmitting a first uplink signal to a base station in a first uplink period within the time period; receiving, from the base station, downlink control information (DCI) including an uplink grant in a downlink period within the time period; and transmitting a second uplink signal to the base station in a second uplink period indicated by the uplink grant within the time period. Accordingly, the performance of the communication system may be increased.

Description

Method and apparatus for transmitting and receiving signals in communication systems supporting unlicensed bands {METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING SIGNAL IN COMMUNICATION SYSTEM SUPPORTING UNLICENSED BAND}

The present invention relates to a signal transmission and reception technology in a communication system, and more particularly, to a channel access technology and a signal transmission and reception technology in a communication system supporting an unlicensed band.

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). Communication technologies are needed to meet the requirements of eMBB, URLLC, and mMTC.

On the other hand, in order to process the rapidly increasing wireless data, communication using an unlicensed band may be used. Currently, communication technologies that use unlicensed bands include LTE-U (LTE-Unlicensed), LAA (Licensed-Assisted-Access), and MultiFire (MulteFire). Can support standalone mode to operate. However, in the unlicensed band, the initial access procedure, the signal transmission procedure, the channel access method suitable for the flexible frame structure, and the broadband carrier operation are not clearly defined. Therefore, it is necessary to clearly define the operation of the base station and the terminal for the above-described technical elements.

An object of the present invention for solving the above problems is to provide a method and apparatus for transmitting and receiving signals in a communication system supporting an unlicensed band.

In order to achieve the above object, a method of operating a terminal according to a first embodiment of the present invention includes: acquiring a time interval for occupying a channel by performing an LBT operation, the first in a first uplink interval within the time interval. Transmitting an uplink signal to a base station, receiving a DCI including an uplink grant from the base station in a downlink interval within the time interval, and a second uplink indicated by the uplink grant within the time interval And transmitting a second uplink signal to the base station in the interval.

Here, the second uplink period may be located after the downlink period, and may fall within the time period.

Here, information indicating an end point of the time period or information indicating whether the second uplink period belongs to the time period may be transmitted from the terminal to the base station.

Here, the time interval initiated by the terminal may be shared with the base station, and the configuration information of the downlink interval may be transmitted from the terminal to the base station.

Here, the transmission resource of the second uplink signal may overlap with the transmission resource of the PUSCH indicated by the configuration grant, and the PUSCH indicated by the configuration grant may not be transmitted.

Here, an LBT operation for transmission of the second uplink signal may be performed, and information indicating an LBT operation for transmission of the second uplink signal may be transmitted from the base station to the terminal.

Here, the second uplink signal may include one or more of PUSCH, PUCCH, and SRS, and the PUCCH is HARQ response to the PDSCH received from the base station, CSI, downlink received signal strength measurement information, and scheduling. It may contain one or more of the requests.

A method of operating a base station according to a second embodiment of the present invention for achieving the above object includes receiving a first uplink signal from the terminal in a first uplink interval within a time interval initiated by the terminal, the time interval Transmitting a DCI including an uplink grant to the terminal in a downlink interval within the time interval, and receiving a second uplink signal from the terminal in a second uplink interval indicated by the uplink grant within the time interval It may include steps.

Here, the second uplink period may be located after the downlink period, and may fall within the time period.

Here, information indicating an end point of the time period or information indicating whether the second uplink period belongs to the time period may be received from the terminal.

Here, the time interval may be shared with the base station, and configuration information of the downlink interval may be received from the terminal.

Here, the transmission resource of the second uplink signal may overlap with the transmission resource of the PUSCH indicated by the configuration grant, and the PUSCH indicated by the configuration grant may not be received.

Here, information indicating whether transmission of a third uplink signal according to the configuration grant is possible in configuration grant resources indicated by a configuration grant after the downlink interval within the time interval is provided to the terminal in the downlink interval. Can be transmitted.

Here, the second uplink signal may include one or more of PUSCH, PUCCH, and SRS, and the PUCCH is HARQ response to the PDSCH transmitted from the base station, CSI, downlink received signal strength measurement information, and scheduling. It may contain one or more of the requests.

The terminal according to the third embodiment of the present invention for achieving the above object includes a processor, a memory in electronic communication with the processor, and instructions stored in the memory, and when the instructions are executed by the processor, The commands include: the terminal acquires a time interval for occupying a channel by performing an LBT operation, transmits a first uplink signal to the base station in a first uplink interval within the time interval, and downlink within the time interval Operation to cause DCI including an uplink grant in a period to be received from the base station and to transmit a second uplink signal to the base station in a second uplink period indicated by the uplink grant in the time period do.

Here, the second uplink period may be located after the downlink period, and may fall within the time period.

Here, the time interval initiated by the terminal may be shared with the base station, and the configuration information of the downlink interval may be transmitted from the terminal to the base station.

Here, the transmission resource of the second uplink signal may overlap with the transmission resource of the PUSCH indicated by the configuration grant, and the PUSCH indicated by the configuration grant may not be transmitted.

Here, information indicating that the time interval initiated by the terminal is intercepted by the base station may be received from the base station in the downlink interval.

Here, the second uplink signal may include one or more of PUSCH, PUCCH, and SRS, and the PUCCH is HARQ response to the PDSCH received from the base station, CSI, downlink received signal strength measurement information, and scheduling. It may contain one or more of the requests.

According to the present invention, the channel occupancy time (COT) initiated by the terminal can be shared with the base station. The base station may transmit an uplink grant to the terminal in a downlink period in the COT, and may receive an uplink signal from the terminal in an uplink period indicated by the uplink grant in the COT. That is, when the COT initiated by the terminal is shared with the base station, and communication controlled by the terminal in the corresponding COT is terminated, communication within the COT may be performed under the control of the base station instead of the terminal. Therefore, radio resources can be used efficiently and performance of a communication system can be improved.

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.
3A is a conceptual diagram showing a first embodiment of a communication method within a COT.
3B is a conceptual diagram showing a second embodiment of a communication method within a COT.
4A is a conceptual diagram illustrating a first embodiment of a method of setting configuration grant resources.
4B is a conceptual diagram illustrating a second embodiment of a method of setting configuration grant resources.
5A is a conceptual diagram showing a first embodiment of a method for transmitting discontinuous PUSCH within one COT.
5B is a conceptual diagram illustrating a second embodiment of a method for transmitting discontinuous PUSCH within one COT.
6 is a conceptual diagram illustrating a first embodiment of a method for setting a downlink period in a COT initiated by a terminal.
7A is a conceptual diagram illustrating a first embodiment of a method for transmitting a downlink signal in a COT initiated by a terminal.
7B is a conceptual diagram illustrating a second embodiment of a method for transmitting a downlink signal in a COT initiated by a terminal.
7C is a conceptual diagram illustrating a third embodiment of a method for transmitting a downlink signal in a COT initiated by a terminal.
8 is a conceptual diagram illustrating a fourth embodiment of a method for transmitting a downlink signal in a COT initiated by a terminal.
9 is a conceptual diagram illustrating a first embodiment of a method of early stopping COT initiated by a terminal.
10A is a conceptual diagram illustrating a first embodiment of a channel occupancy method of a terminal in consideration of a DRS-related window.
10B is a conceptual diagram illustrating a second embodiment of a channel occupancy method of a terminal in consideration of a DRS-related window.
11A is a conceptual diagram illustrating a first embodiment in which a plurality of terminals simultaneously access the same channel.
11B is a conceptual diagram illustrating a second embodiment in which a plurality of terminals simultaneously access the same channel.

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, or 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.

A communication system to which embodiments according to the present invention are applied will be described. The communication system may be a 4G communication system (eg, a long-term evolution (LTE) communication system, an LTE-A communication system), a 5G communication system (eg, a new radio (NR) communication system), or the like. A 4G communication system can support communication in a frequency band of 6 GHz or less, and a 5G communication system can support communication in a frequency band of 6 GHz or more as well as a frequency band of 6 GHz or less. The communication system to which the embodiments according to the present invention are applied is not limited to the contents described below, and the embodiments according to the present invention can be applied to various communication systems. Here, the communication system may be used with the same meaning as a communication network, and “LTE” may indicate “4G communication system”, “LTE communication system” or “LTE-A communication system”, and “NR” May designate “5G communication system” or “NR communication system”.

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). In addition, the communication system 100 includes a core network (eg, a serving-gateway (S-GW), a packet data network (PDN)-gateway), and a mobility management entity (MME)). It may contain more. When the communication system 100 is a 5G communication system (eg, a new radio (NR) system), the core network is an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc. It may include.

The plurality of communication nodes 110 to 130 may support communication protocols (eg, LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) specified in the 3rd generation partnership project (3GPP) standard. The plurality of communication nodes 110 to 130 are code division multiple access (CDMA) technology, wideband CDMA (WCDMA) technology, time division multiple access (TDMA) technology, frequency division multiple access (FDMA) technology, orthogonal frequency division (OFDM) technology. multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA Technology, NOMA (Non-orthogonal Multiple Access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (Space Division Multiple Access) technology, etc. Can support. 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, 120-2, and a plurality of terminals 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 cell 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 to the cell 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 cell coverage of the third base station 110-3. have. The first terminal 130-1 may belong to the cell coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the cell 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 (NB), evolved NodeB (eNB), gNB, advanced base station (ABS), and HR. -BS (high reliability-base station), BTS (base transceiver station), radio base station, radio transceiver, access point, access node, radio access station (RAS) ), MMR-BS (mobile multihop relay-base station), RS (relay station), ARS (advanced relay station), HR-RS (high reliability-relay station), HNB (home NodeB), HeNB (home eNodeB), It may be referred to as a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), and the like.

Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 is a user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), HR-MS (high reliability-mobile station), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable It may be referred to as a portable subscriber station, a node, a device, an on board unit (OBU), and the like.

Meanwhile, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands 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 link or a non-ideal backhaul link, , Information can be exchanged with each other through an ideal backhaul link or a non-ideal backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to the core network through an ideal backhaul link or a non-ideal backhaul link. 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.

In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits MIMO (e.g., single user (SU)-MIMO, multi-user (MU)- MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, direct communication between terminals (device to device communication, D2D) (or , ProSe (proximity services)), Internet of Things (IoT) communication, dual connectivity (DC), 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 may 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, and 130-4 belonging to their cell coverage. , 130-5, 130-6) and the CA 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 can control D2D between the fourth terminal 130-4 and the fifth terminal 130-5. And, each of the fourth terminal 130-4 and the fifth terminal 130-5 may perform D2D under the control of the second base station 110-2 and the third base station 110-3, respectively. .

On the other hand, a communication system (e.g., NR communication system) supports one or more services from an enhanced mobile broadband (eMBB) service, an ultra-reliable and low-latency communication (URLLC) service, and a massive machine type communication (mMTC) service I can. Communication can be performed to satisfy the technical requirements of the services in the communication system. In the URLLC service, a requirement of transmission reliability may be 1-10 ^-5 , and a requirement of uplink and downlink user plane delay time may be 0.5 ms.

In the following embodiments, a method of occupying a channel in a communication system supporting an unlicensed band, a method of transmitting and receiving control information related to a channel occupancy time, and the like will be described. The following embodiments may be applied not only to an NR communication system, but also to other communication systems (eg, LTE communication systems).

The NR communication system may support a system bandwidth (eg, a carrier bandwidth) wider than the system bandwidth provided by the LTE communication system in order to efficiently use a wide frequency band. For example, the maximum system bandwidth supported by the LTE communication system may be 20 MHz. On the other hand, the NR communication system can support a carrier bandwidth of up to 100 MHz in a frequency band of 6 GHz or less, and a carrier bandwidth of 400 MHz in a frequency band of 6 GHz or more.

In a communication system (eg, an NR communication system), the numerology applied to physical signals and channels may vary. Numerology can be varied to meet the various technical requirements of the communication system. In a communication system to which a cyclic prefix (CP) based OFDM waveform technology is applied, a newer roller may include a subcarrier spacing and a CP length (or CP type). Table 1 may be a first embodiment of a neurology configuration for CP-based OFDM. The subcarrier intervals may have a relationship of an exponential multiple of 2 to each other, and the CP length may be scaled at the same ratio as the OFDM symbol length. Some of the neurons in Table 1 may be supported according to the frequency band in which the communication system operates. When the subcarrier spacing is 60 kHz, an extended CP may be additionally supported.

In the following, the frame structure in the communication system will be described. Building blocks in the time domain may be subframes, slots, and/or mini slots. The subframe may be used as a transmission unit, and the length of the subframe may have a fixed value (eg, 1 ms) regardless of the subcarrier interval. When a general CP is used, a slot may include consecutive symbols (eg, 14 OFDM symbols). The length of the slot may be variable different from the length of the subframe, and may be inversely proportional to the subcarrier spacing. The slot may be used as a scheduling unit, and may be used as a setting unit for scheduling and hybrid automatic repeat request (HARQ) timing. The length of the actual time resource used for each scheduling may not match the length of the slot.

The base station can schedule a data channel (e.g., a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), a physical sidelink shared channel (PSSCH)) using some or all of the symbols constituting the slot. . Alternatively, the base station may schedule a data channel using a plurality of slots. The mini slot may be used as a transmission unit, and the length of the mini slot may be set shorter than the length of the slot. For example, a mini slot may be a scheduling or transmission unit having a length shorter than that of the slot. In a communication system, a slot having a length shorter than that of an existing slot may be referred to as a mini slot. The mini-slot-based scheduling operation can be used for partial slot transmission, URLLC data transmission, analog beamforming-based multi-user scheduling, etc. in the "unlicensed band" or "the coexistence band of the NR communication system and the LTE communication system". . In the NR communication system, since the PDCCH (pysical downlink control channel) monitoring period and/or the duration of the data channel is set to be shorter than that of the existing slot, mini-slot-based transmission may be supported.

In the frequency domain of the NR communication system, the building block may be a physical resource block (PRB). One PRB may include consecutive subcarriers (eg, 12 subcarriers) regardless of the newer roller. Therefore, the bandwidth occupied by one PRB may be proportional to the subcarrier spacing of the newer roller. The PRB may have a reduced frequency length. In this case, it may be used as a resource allocation unit for a control channel and/or a data channel in the data channel domain. The minimum unit for resource allocation of the downlink control channel may be a control channel element (CCE). One CCE may include one or more PRBs. Resource allocation of the data channel may be performed in units of PRBs or resource block groups (RBGs). One RBG may include one or more consecutive PRBs.

In the NR communication system, a slot (eg, a slot format) may be composed of a combination of one or more of a downlink period, a flexible period (or an unknown period), and an uplink period. Each of the downlink period, the flexible period, and the uplink period may be composed of one or more consecutive symbols. The flexible section may be located between a downlink section and an uplink section, between a first downlink section and a second downlink section, between a first uplink section and a second uplink section, and the like. When a flexible section is inserted between the downlink section and the uplink section, the flexible section can be used as a guard section.

One slot may include one or more flexible sections. Alternatively, one slot may not include a flexible section. Until the flexible period is overridden by a downlink period, an uplink period, etc., the terminal operates a predefined operation in the flexible period or a semi-static or periodically set operation from the base station (e.g., PDCCH Monitoring operation, synchronization signal/physical broadcast channel (SS/PBCH) block reception and measurement operation, CSI-RS (channel state information-reference signal) reception and measurement operation, downlink semi-persistent scheduling (SPS) PDSCH reception operation, A sounding reference signal (SRS) transmission operation, a physical random access channel (PRACH) transmission operation, a periodically configured PUCCH transmission operation, a PUSCH transmission operation according to a configured grant, etc.) may be performed. Alternatively, the terminal may not perform any operation in the flexible period until the flexible period is overridden by the downlink period or the uplink period.

The slot format may be semi-fixedly set by higher layer signaling (eg, radio resource control (RRC) signaling). Information indicating the semi-fixed slot format may be included in system information, and the semi-fixed slot format may be set cell-specifically. For example, the cell-specific slot format may be configured through the RRC parameter “TDD-UL-DL-ConfigCommon”. In addition, the slot format may be additionally configured for each terminal through terminal-specific upper layer signaling (eg, RRC signaling). For example, the UE-specific slot format may be configured through the RRC parameter “TDD-UL-DL-ConfigDedicated”. The flexible period of the slot format configured specifically for the cell may be overridden by the downlink period or the uplink period by UE-specific higher layer signaling. In addition, the slot format may be dynamically indicated by a slot format indicator (SFI) included in downlink control information (DCI).

The UE may perform a downlink operation, an uplink operation, and a sidelink operation in a bandwidth part. The bandwidth portion may be defined as a set of consecutive PRBs in the frequency domain having a specific neuron. Only one neuron may be used for transmission of a control channel or a data channel in one bandwidth portion. The terminal performing the initial access procedure may obtain configuration information of an initial bandwidth portion from the base station through system information. A terminal operating in an RRC connected state may obtain configuration information of a bandwidth portion from a base station through terminal-specific upper layer signaling.

The configuration information of the bandwidth portion may include a newer roller applied to the bandwidth portion (eg, subcarrier spacing and CP length). In addition, the setting information of the bandwidth portion may further include information indicating the position of the starting PRB of the bandwidth portion and information indicating the number of PRBs constituting the bandwidth portion. At least one of the bandwidth portion(s) set in the terminal may be activated. For example, each of one uplink bandwidth portion and one downlink bandwidth portion may be activated within one carrier. In a time division duplex (TDD)-based communication system, a pair of an uplink bandwidth portion and a downlink bandwidth portion may be activated. The base station may set a plurality of bandwidth portions in the terminal within one carrier and may switch the active bandwidth portion of the terminal.

In the embodiments, that a certain frequency band (for example, a carrier, a bandwidth part, a listen before talk (LBT) subband, a guard band, etc.) is activated means that the base station or the terminal is signaled using the corresponding frequency band. It may mean that it is in a state that can transmit and receive. Further, that a certain frequency band is activated may mean that a radio frequency (RF) filter (eg, a band pass filter) of a transceiver is operating including the frequency band.

The minimum resource unit constituting the PDCCH may be a resource element group (REG). REG may consist of one PRB (eg, 12 subcarriers) in the frequency domain and one OFDM symbol in the time domain. Therefore, one REG may include 12 RE (resource elements). DM-RS (demodulation reference signal) for decoding of the PDCCH may be mapped to 3 REs among 12 REs constituting the REG, and control information (eg, modulated DCI) is the remaining 9 REs Can be mapped to.

One PDCCH candidate may consist of one CCE or aggregated CCEs. One CCE may be composed of a plurality of REGs. The NR communication system may support CCE aggregation levels 1, 2, 4, 8, 16, and the like, and one CCE may consist of 6 REGs.

The CORESET (control resource set) may be a resource region in which the UE performs blind decoding of the PDCCH. CORESET may be composed of a plurality of REGs. CORESET may be composed of one or more PRBs in the frequency domain and one or more symbols (eg, OFDM symbols) in the time domain. Symbols constituting one CORESET may be continuous in the time domain. PRBs constituting one CORESET may be continuous or discontinuous in the frequency domain. One DCI (eg, one PDCCH) may be transmitted within one CORESET. A plurality of CORESETs may be set from a cell perspective or a terminal perspective, and a plurality of CORESETs may overlap each other in time-frequency resources.

CORESET may be set in the terminal by PBCH (eg, system information transmitted through the PBCH). The ID (identifier) of CORESET set by the PBCH may be 0. That is, the CORESET set by the PBCH may be referred to as CORESET #0. A terminal operating in an RRC idle state may perform a monitoring operation at CORESET #0 in order to receive an initial PDCCH in an initial access procedure. Not only the terminal operating in the RRC idle state, but also the terminal operating in the RRC connected state can perform a monitoring operation in CORESET #0. CORESET may be set in the terminal by system information other than system information transmitted through the PBCH (eg, system information block type 1 (SIB1)). For example, in order to receive a random access response (or Msg2) in a random access procedure, the UE may receive SIB1 including setting information of CORESET. In addition, CORESET may be set in the terminal by terminal-specific higher layer signaling (eg, RRC signaling).

One or more CORESETs may be set for the UE for each downlink bandwidth part. Here, that the CORESET is set in the bandwidth part may mean "the CORESET is logically combined with the bandwidth part, and the terminal monitors the corresponding CORESET in the bandwidth part". The initial downlink active bandwidth part may include CORESET #0, and may be mutually combined with CORESET #0. CORESET #0 having a QCL (quasi co-location) relationship with an SS/PBCH block in a primary cell (PCell), a secondary cell (SCell), and a primary secondary cell (PSCell) Can be set for the terminal. CORESET #0 in the secondary cell may not be set for the terminal.

The search space may be a set of candidate resource regions in which the PDCCH can be transmitted. The UE may perform blind decoding on each of the PDCCH candidates within a predefined search space. The UE may determine whether the PDCCH has been transmitted to itself by performing a cyclic redundancy check (CRC) on the blind decoding result. When it is determined that the PDCCH is a PDCCH for the UE, the UE may receive the PDCCH.

The PDCCH candidate may be composed of CCE(s) selected by a hash function predefined within a CORESET or a search space occasion. The search space may be defined/set for each CCE aggregation level. In this case, the sum of the search spaces for all CCE aggregation levels may be referred to as a search space set. In embodiments, "search space" may mean "search space set", and "search space set" may mean "search space".

The set of search spaces may be logically associated with one CORESET. One CORESET can be logically combined with one or more sets of search spaces. A common search space set set through the PBCH may be used to monitor DCI scheduling a PDSCH for transmitting SIB1. The ID of the common search space set configured through the PBCH may be set to 0. That is, the common search space set configured through the PBCH may be defined as a type 0 PDCCH common search space set or search space set #0. Search space set #0 can be logically combined with CORESET #0.

The search space set may be divided into a common search space set and a UE-specific search space set according to a purpose or related operation. The common DCI may be transmitted in the common search space set, and the terminal-specific DCI may be transmitted in the terminal-specific search space set. In consideration of scheduling degrees of freedom and/or fallback transmission, a UE-specific DCI may be transmitted even in a common search space set. For example, the common DCI may include resource allocation information of PDSCH for transmission of system information, paging, power control command, SFI, preemption indicator, and the like. The terminal-specific DCI may include PDSCH resource allocation information, PUSCH resource allocation information, and the like. A plurality of DCI formats may be defined according to the DCI payload, size, and type of radio network temporary identifier (RNTI).

In the following embodiments, the common search space may be referred to as a CSS (common search space), and the common search space set may be referred to as a CSS set. In addition, in the following embodiments, the UE-specific search space may be referred to as a UE-specific search space (USS), and the UE-specific search space set may be referred to as a USS set.

In the following embodiments, the signaling is PHY (physical) signaling (eg, DCI), MAC (medium access control) signaling (eg, MAC CE (control element)), and RRC signaling (eg, MIB ( master information block), system information block (SIB), cell-specific RRC signaling, terminal-specific RRC signaling, etc.). In addition, signaling (or setting) may mean both signaling (or setting) by an explicit method and signaling (or setting) by an implicit method. In the following embodiments, “signal” may be used as a meaning including “physical layer signal” and “physical layer channel”. For example, the downlink signal is a downlink physical layer signal (e.g., DM-RS, CSI-RS, PT (phase tracking)-RS, SS/PBCH block, etc.) and a downlink physical layer channel (e.g. , PDCCH, PDSCH).

Embodiments of the present invention can be applied to various communication scenarios using an unlicensed band. For example, with the help of the primary cell of the licensed band, the cell of the unlicensed band may be set as a secondary cell, and the carrier of the secondary cell may be aggregated with other carriers. Alternatively, a cell in an unlicensed band (eg, a secondary cell) and a cell in a licensed band (eg, a primary cell) may support a dual connectivity operation. Therefore, the transmission capacity can be increased. Alternatively, the cells of the unlicensed band may independently perform the function of the primary cell. Alternatively, the downlink carrier of the licensed band may be combined with the uplink carrier of the unlicensed band, and the combined carriers may perform one cell function. Conversely, the uplink carrier of the licensed band can be combined with the downlink carrier of the unlicensed band, and the combined carriers can perform one cell function. In addition, embodiments of the present invention can be applied not only to a communication system supporting an unlicensed band, but also to other communication systems (eg, a communication system supporting a licensed band).

In communication in an unlicensed band, a contention-based channel access method may be used to satisfy spectrum regulation conditions and coexist with an existing communication node (eg, a Wi-Fi terminal). For example, a communication node attempting to access a channel of an unlicensed band may check the channel occupancy status by performing a clear channel assessment (CCA) operation. The transmitting node (e.g., a communication node performing a transmitting operation) is based on a predefined (or preset) CCA threshold, whether the channel is in a busy state or an idle state. You can check whether it is. When the channel is in an idle state, the transmitting node may transmit a signal and/or a channel in the corresponding channel. The above-described operation may be referred to as a “listen before talk (LBT) operation”.

LBT operations can be classified into four categories depending on whether the LBT operation is performed or not and an application method. The first category (eg, LBT category 1) may be a method in which the transmitting node does not perform an LBT operation. That is, when the first category is used, the transmitting node may transmit a signal and/or a channel without performing a channel sensing operation (eg, a CCA operation). The second category (eg, LBT category 2) may be a method in which a transmitting node performs an LBT operation without a random back-off. LBT category 2 may be referred to as “one-shot LBT operation”. In the third category (eg, LBT category 3), the transmitting node performs an LBT operation based on a random backoff value (eg, a random backoff counter) according to a fixed contention window (CW). It can be a way to do it. The fourth category (eg, LBT category 4) may be a method in which a transmitting node performs an LBT operation based on a random backoff value according to a contention window of a variable size.

The LBT operation may be performed in a specific frequency bundle unit. The frequency bundle may be referred to as “LBT subband”, “subband”, or “resource block (RB) set”. In the following embodiments, the LBT subband or subband may mean an RB set. Here, the LBT operation may include the aforementioned CCA operation. Alternatively, the LBT operation may include "CCA operation + signal and/or channel transmission operation according to CCA operation". The bandwidth of the LBT subband may vary depending on spectrum regulations, frequency bands, communication systems, operators, and manufacturers. For example, in a band in which a Wi-Fi terminal and a 3GPP terminal coexist, the bandwidth of the LBT subband may be 20 MHz (or about 20 MHz). The communication node may perform a channel sensing operation and/or a data transmission operation according to the channel sensing operation in units of 20 MHz (or units of about 20 MHz).

For example, the LBT subband may be a set of consecutive RBs corresponding to about 20 MHz. In this case, the bandwidth of the set of consecutive RBs may not exceed 20 MHz. In the following embodiments, “the LBT subband is referred to as X _L MHz” may mean “the LBT subband has a bandwidth of X _L MHz or about X _L MHz”. Unless otherwise stated, X _L may be assumed to be 20. In the following embodiments, RB may mean a PRB constituting a bandwidth portion depending on the case. Alternatively, RB may mean CRB (common RB) or VRB (virtual RB). In particular, when RB is used in the sense of an RB constituting a carrier, the RB may refer to a CRB constituting a carrier. In the NR communication system, the CRB may mean an RB on a common RB grid set in the terminal based on point A.

Considering the above-described LBT operation, the bandwidth of the carrier and/or bandwidth portion set in the terminal may be set to a multiple of X _L. For example, the carrier and/or bandwidth portion may be set to 20, 40, 60, 80 MHz, and the like. In the following embodiments, "the carrier and/or the bandwidth portion is referred to as X MHz" may mean "the bandwidth of the carrier and/or the bandwidth portion is X MHz or about X MHz". For example, the carrier and/or bandwidth portion may comprise a set of contiguous RBs corresponding to about X MHz. In the NR communication system, the carrier and/or bandwidth portion may be defined as a set of CRBs in a common RB grid. The bandwidth portion can be set within one carrier. Alternatively, the bandwidth portion may be set to include a plurality of carriers. When the bandwidth portion includes a plurality of carriers, the bandwidth portion may be logically coupled (eg, associated) with the plurality of carriers.

In the communication of the unlicensed band, the transmitting node can occupy a channel for a certain time when the LBT operation is successful. In this case, the channel occupancy time or the channel occupancy period may be referred to as “channel occupancy time (COT)” or channel occupancy (CO). That is, COT or CO may refer to a time period occupied by a communication node (eg, a base station or a terminal). "The sending node succeeds in the LBT operation" may mean "the sending node has secured the COT". The transmitting node may transmit a signal and/or a channel by using some or all of the COT that it initiated. In addition, the COT initiated by the transmitting node may be shared with the receiving node (eg, a communication node performing a receiving operation). Here, the LBT operation may be performed to check the occupied state, the use state, or the connection state of the channel. The LBT operation may mean a channel sensing operation, an occupation status confirmation operation, a channel status confirmation operation, or a connection status confirmation operation.

In the COT shared between the transmitting node and the receiving node, the receiving node can perform not only the receiving operation but also the transmitting operation. Therefore, the transmitting node can perform not only the transmission operation but also the reception operation within the shared COT. In embodiments, a transmitting node may mean a node that has initiated or initiated a COT (eg, an initiating node), and a receiving node is a signal from a corresponding COT without starting or initiating a COT. It may mean a node that transmits/receives.

3A is a conceptual diagram showing a first embodiment of a communication method within a COT.

Referring to FIG. 3A, a base station (eg, gNB) may acquire a COT by performing a CCA operation. The base station may transmit a downlink transmission burst at the beginning of the COT. The downlink transmission burst may be a set of consecutive downlink signals and/or channels in the time domain. The uplink transmission burst may be a set of consecutive uplink signals and/or channels in the time domain. When signals and/or channels constituting a downlink and uplink transmission burst are continuous in the time domain, it may mean that a gap between transmissions of signals and/or channels is less than or equal to a reference value. For example, the reference value may be 0. For another example, the reference value may be a value greater than 0 (eg, 16 μs). The COT initiated by the base station may be shared with the terminal. The terminal may transmit an uplink transmission burst within the shared COT.

In this case, the terminal may perform an LBT operation for transmission of an uplink transmission burst. For example, the UE may perform a CCA operation after transmission of the downlink transmission burst is finished. When it is determined that the channel state is idle as a result of the CCA operation, the terminal may transmit an uplink transmission burst. Alternatively, the terminal may transmit an uplink transmission burst without performing a CCA operation. For example, when a time interval (eg, T1) between a downlink transmission burst and an uplink transmission burst is less than a preset value (eg, 16 μs), the terminal performs an uplink transmission burst without performing a CCA operation. Can send. T1 may be a time interval between the end point of the downlink transmission burst and the start point of the uplink transmission burst.

3B is a conceptual diagram showing a second embodiment of a communication method within a COT.

Referring to FIG. 3B, the UE may acquire a COT by performing a CCA operation. The UE may transmit an uplink transmission burst at the beginning of the COT. The COT initiated by the terminal may be shared with the base station. The base station may transmit a downlink transmission burst within the shared COT. In this case, the base station may perform an LBT operation for transmission of a downlink transmission burst. For example, the base station may perform a CCA operation after transmission of an uplink transmission burst is finished. When it is determined that the channel state is the idle state as a result of the CCA operation, the base station may transmit a downlink transmission burst. Alternatively, the base station may transmit a downlink transmission burst without performing a CCA operation. For example, if the time interval (eg, T2) between the uplink transmission burst and the downlink transmission burst is less than a preset value (eg, 16 μs), the base station performs a downlink transmission burst without performing a CCA operation. Can send. T2 may be a time interval between the end point of the uplink transmission burst and the start point of the downlink transmission burst.

The maximum occupancy time (or maximum transmission time of a signal) of a channel according to the CCA operation may be defined as a maximum COT (MCOT). In embodiments, the maximum occupancy time of the channel according to the CCA operation performed by the base station may be referred to as "downlink MCOT", and the maximum occupancy time of the channel according to the CCA operation performed by the terminal is "uplink MCOT. May be referred to as ". Accordingly, the COT initiated by the base station cannot exceed the downlink MCOT, and the COT initiated by the terminal cannot exceed the uplink MCOT. The downlink MCOT may be predefined in the technical standard according to frequency regulation, channel access priority class, and the like. The uplink MCOT may be predefined in the technical standard according to frequency regulation and channel access priority class. Alternatively, the base station may inform the UE of the uplink MCOT.

The transmitting node (or receiving node) signals information about the COT (eg, COT configuration information) that it has acquired (eg, DCI signaling, uplink control information (UCI) signaling, RRC signaling, etc.) Through this, the receiving node (or the transmitting node) may be notified. The COT configuration information may include a start point of the COT, an end point of the COT, and a duration of the COT (eg, the length of the COT). The COT setting information notified by the transmitting node (or receiving node) to the receiving node (or transmitting node) may be different from information about the COT actually obtained by the transmitting node. The COT setting information may be dynamically indicated, semi-fixedly set, or may be predefined and shared among nodes in advance.

For example, the base station may inform the terminal of the configuration information of the COT started by itself. In this case, the specific operation of the terminal may depend on the COT configuration information obtained from the base station. For example, the PDCCH monitoring operation within the COT set by the base station may be different from the PDCCH monitoring operation outside the COT set by the base station. Specifically, outside the COT, the UE may perform a blind decoding operation on the DM-RS of the PDCCH candidate(s) and may not perform a blind decoding operation on the data of the PDCCH candidate(s). In addition, the UE may perform a PDCCH monitoring operation for relatively many PDCCH candidates in some periods within the COT (eg, the first slot of the downlink transmission burst), and other partial periods in the COT (eg, downlink A PDCCH monitoring operation may be performed for relatively few PDCCH candidate(s) in the remaining slot(s) except for the first slot of the link transmission burst. Accordingly, the terminal can reduce power consumption according to the PDCCH monitoring operation by obtaining the COT configuration information from the base station.

The terminal may inform the base station of the configuration information of the COT initiated by it. In this case, the specific operation of the base station may depend on the COT configuration information received from the terminal. For example, the transmission operation of the base station in the COT shared between the base station and the terminal may be determined based on the configuration information of the shared COT.

Meanwhile, communication nodes (eg, base stations and terminals) performing LBT operations in an unlicensed band may be classified into load-based equipment (LBE) and frame-based equipment (FBE). In addition, the LBT operation method may include an LBE operation method and an FBE operation method. When the LBE operation method is used, the communication node may attempt to occupy a channel by performing an additional CCA operation after failing the CCA operation. For example, the LBE may perform an LBT operation based on a random backoff value according to a contention window. The LBT operation method according to the third and fourth categories may be included in the LBE operation method. "The CCA operation has failed" may mean "the channel is not occupied by the CCA operation".

When the FBE operation method is used, the communication node can perform the CCA operation every fixed frame or fixed frame period (FFP) at the start point or immediately before the start point, and if the CCA operation fails, the next fixed The CCA operation cannot be performed again until the time when the CCA operation is performed in the frame or the next FFP (eg, the start time or just before the start time). On the other hand, the FBE may continuously perform the transmission/reception operation during the corresponding FFP when the CCA operation succeeds at the start point or immediately before the FFP. FFP may be composed of a COT (or MCOT) and an idle period. The idle period may be 5% of the total length of the FFP or COT.

For example, when the FFP is 10 ms, the COT (or MCOT) and the idle period constituting the FFP may be 9.5 ms and 0.5 ms, respectively. The idle section can be placed just before the COT. The communication node may perform the LBT operation in the idle period, and if it is determined that the channel is idle as a result of the LBT operation, it may occupy the channel for the maximum COT (or MCOT). The LBT operation performed by the FBE in an idle period or a gap period (eg, a gap period in the COT) may be an LBT operation according to the second category. Alternatively, the LBT operation performed by the FBE in the idle period or the gap period (eg, a gap period in the COT) may be different from the LBT operations according to the first to fourth categories. For example, the FBE may perform an energy detection operation during a slot duration of at least Tµs length within an idle period or a gap period, and is based on a comparison result between the energy detection operation result and the energy detection threshold. Thus, the channel state can be determined. T may be predefined in the technical standard. For example, it may be T=9. The above-described LBT operation may be referred to as "LBT operation according to the 2-1 category". The FBE operation method can be used when an environment in which other communication systems do not coexist is guaranteed from the viewpoint of frequency regulation. For example, in an NR or LTE system, the FBE operation method may be used in an environment where a WiFi system and a device do not coexist.

In the FBE operation scheme, the COT may be initiated by the base station. The base station may transmit a downlink transmission burst to the terminal from the start of COT when the LBT operation is successful in the idle period. The COT initiated by the base station may be shared with the terminal. In this case, the terminal may transmit an uplink transmission burst to the base station within the shared COT. In addition, in the FBE operation method, the COT may be initiated by the terminal. The terminal may transmit an uplink transmission burst to the base station from the start of COT when the LBT operation is successful in the idle period. The COT initiated by the terminal may be shared with the base station. In this case, the base station may transmit a downlink transmission burst to the terminal within the shared COT.

The base station may transmit configuration information for LBT operation to the terminal. The configuration information for the LBT operation may be transmitted through higher layer signaling (eg, RRC signaling, SIB, SIB1). The configuration information for the LBT operation may include information indicating an LBT operation method (eg, an LBE operation method or an FBE operation method) performed in the terminal. The terminal may receive configuration information for LBT operation from the base station. When the FBE operation method is used, the setting information for the LBT operation may further include information about the FFP (eg, the length of the FFP or the FFP). The terminal determines the arrangement position of each FFP, the arrangement position of the COT constituting each FFP, and/or the arrangement position of the idle section constituting each FFP in the time domain, and the setting information for the LBT operation (for example, information on the FFP. ) And predefined rules. The FFP performed (or initiated) by the base station may be distinguished from the FFP performed (or initiated) by the terminal. The terminal may receive information on the FFP performed by the base station from the base station. At the same time or separately, the terminal may receive information about the FFP performed by the terminal from the base station.

The following embodiments can be applied to both the LBE operation method and the FBE operation method. In the following embodiments, COT may mean COT based on an LBE operation. In addition, in the following embodiments, COT may mean COT based on an FBE operation.

The following embodiments can be applied not only for COT initiated by the base station but also for COT initiated by the terminal.

Meanwhile, the uplink data channel (eg, PUSCH) may be scheduled by a dynamic grant or a configured grant. For example, the dynamic grant may be a DCI including scheduling information, and the base station may transmit the dynamic grant (eg, DCI) to the terminal through a downlink control channel (eg, PDCCH). In addition, the configuration grant may include information for semi-fixed configuration, semi-permanent configuration, and/or dynamic reconfiguration of scheduling information, and the base station transmits the configuration grant to higher layer signaling (e.g., RRC signaling) and/or physical layer It can be transmitted to the terminal through dynamic signaling. In the following embodiments, a channel (eg, PDCCH, PDSCH, PUCCH, PUSCH, etc.) may mean "a signal including data and/or control information" or "a radio resource used for transmission and reception of the corresponding signal". have.

The terminal may receive, from the base station, configuration information of a resource region (hereinafter referred to as "configuration grant resource") in which the PUSCH scheduled by the configuration grant can be transmitted. When uplink traffic (e.g., uplink shared channel (UL-SCH)) occurs, the UE does not receive a separate scheduling request (SR) and a dynamic grant according to the scheduling request. For example, data, control information) can be transmitted.

In the unlicensed band, the UE can initiate or initiate COT by transmitting the PUSCH according to the configuration grant. In the embodiment shown in FIG. 3B, the uplink transmission burst of the terminal may start from the PUSCH by the configuration grant. That is, the start of the uplink transmission burst of the terminal (e.g., symbols from the first symbol to the X-th symbol (ie, X symbols), slots from the first slot to the Y-th slot (ie Y slots)) may be occupied by the PUSCH by the configuration grant. In this case, the terminal may perform a random backoff-based LBT operation (eg, LBT category 3 or LBT category 4) for channel access. PUSCH may be transmitted in the configuration grant resource. The plurality of configuration grant resources set by the base station to the terminal may be continuous or discontinuous in a specific time interval.

FIG. 4A is a conceptual diagram illustrating a first embodiment of a method of setting configuration grant resources, and FIG. 4B is a conceptual diagram illustrating a second embodiment of a method of setting configuration grant resources.

Referring to FIG. 4A, the base station may transmit configuration information of consecutive 8 configuration grant resources (eg, configuration grant resources #0 to #7) to the terminal within a time interval. That is, eight configuration grant resources may be contiguous in the time domain. The terminal may receive configuration information of configuration grant resources from the base station, and may determine that consecutive 8 configuration grant resources are configured within a time interval. The terminal can acquire the COT by performing the LBT operation. In this case, the UE may continuously transmit the PUSCH in up to 8 configuration grant resources. Here, "the setting grant resources are said to be continuous in the time domain" may mean "the gap between the setting grant resources is less than a reference value". For example, the reference value may be 0. For another example, the reference value may be a value greater than 0 (eg, 16 μs).

On the other hand, the terminal may not perform a signal reception operation by semi-fixed configuration in the symbol (s) in which the configuration grant resource (s) is set. For example, the base station may not set the terminal to perform both a semi-fixed transmission operation and a semi-fixed reception operation in the same symbol (eg, a symbol set as a flexible symbol by setting a semi-fixed slot format). . That is, the terminal may not expect the base station to set the above-described operation. Therefore, when a symbol is set as a configuration grant resource, the UE receives a reception operation according to semi-fixed configuration in the corresponding symbol (e.g., PDCCH, PDSCH by downlink SPS, SS/PBCH block, CSI-RS, PRS (positioning reference). signal), etc.) may not be performed. In this case, it may be difficult for the base station to perform a COT acquisition operation and a downlink signal transmission operation for the terminal before the end of the time period (eg, a time period in which eight set grant resources are set). In the embodiment illustrated in FIG. 4A, it may be difficult for the base station to initiate or initiate a COT for the terminal within a period corresponding to the configuration grant resource #2 or #3. In order to transmit a downlink signal to the terminal, the base station may have to wait until the downlink interval after the end of the time interval to which the consecutive eight configuration grant resources belong. Therefore, downlink transmission may be delayed.

Referring to FIG. 4B, the base station may transmit configuration information of 4 discontinuous configuration grant resources (eg, configuration grant resources #0, #1, #2, and #3) to the terminal within a time interval. . That is, four configuration grant resources may be discontinuous in the time domain. A gap section may exist between the configuration grant resource #1 and the configuration grant resource #2. The terminal may receive configuration information of configuration grant resources from the base station, and may determine that four discontinuous configuration grant resources are configured within a time interval. In this case, it may be difficult for the terminal to continuously transmit a plurality of PUSCHs in the configuration grant resources even when the LBT operation is successful. The above-described setting (eg, operation method) may be helpful in terms of COT initiation of the base station.

For example, in the embodiment shown in FIG. 4B, when the LBT operation is successful in the gap period between the configuration grant resource #1 and the configuration grant resource #2, the base station may transmit a downlink transmission burst. Transmission of the downlink transmission burst may start in a gap period. In the embodiment shown in FIG. 4B, the transmission delay of the downlink transmission burst may be shorter than that of the downlink transmission burst in the embodiment shown in FIG. 4A. That is, the performance gain of downlink communication in the embodiment shown in FIG. 4B may be higher than the performance gain of downlink communication in the embodiment shown in FIG. 4A. When configuration grant resources are discontinuously configured in the time domain, it may be helpful to provide a balance between downlink and uplink channel access.

5A is a conceptual diagram illustrating a first embodiment of a method for transmitting discontinuous PUSCH within one COT, and FIG. 5B is a conceptual diagram illustrating a second embodiment of a method for transmitting discontinuous PUSCH within one COT.

Referring to FIG. 5A, a UE that has succeeded in an LBT operation may start COT by transmitting a PUSCH in a configuration grant resource. In this case, the configuration grant resources set in the terminal may be temporally discontinuous within the COT initiated by the terminal. That is, a gap section may exist between the first set of consecutive configuration grant resources and the second set of consecutive configuration grant resources. The terminal may transmit PUSCH(s) in the first set of contiguous configuration grant resources, may not transmit PUSCH in the gap period, and transmit PUSCH(s) in the second set of contiguous configuration grant resources. I can. That is, the UE may discontinuously transmit a plurality of PUSCHs within one COT. A plurality of PUSCHs may be discontinuous in the time domain.

Referring to FIG. 5B, a UE that has succeeded in an LBT operation may start COT by transmitting a PUSCH in a configuration grant resource. In this case, the configuration grant resources set in the terminal may be temporally continuous within the COT initiated by the terminal. The UE may discontinuously transmit the PUSCH in one set of consecutive configuration grant resources in the COT. In this case, the resource(s) in which the PUSCH is transmitted and/or the resource(s) in which the PUSCH is not transmitted may be determined by the terminal.

In the following embodiments, “a method for a terminal to discontinuously transmit an uplink signal (eg, PUSCH) in a COT” and “a method for supporting discontinuous transmission of an uplink signal” will be described. The COT may be a COT initiated by a terminal or a COT initiated by a base station. The following embodiments can be applied to a COT initiated by a base station as well as a COT initiated by a terminal. When the terminal performs a discontinuous uplink transmission operation within one COT, the first set of consecutive uplink signals (eg, the first set) may be referred to as a first uplink transmission burst, and The second set of one uplink signals (eg, the second set) may be referred to as a second uplink transmission burst. In the time domain, the second uplink transmission burst may be located after the first uplink transmission burst. In the embodiments shown in FIGS. 5A and 5B, the first uplink transmission burst may include two PUSCHs, and the second uplink transmission burst may include three PUSCHs.

Meanwhile, according to the frequency regulation (eg, spectrum regulation) of the unlicensed band, a transmission pause time may not be allowed between the first uplink transmission burst and the second uplink transmission burst. As a method for solving this problem, when a COT initiated by a transmitting node (eg, a terminal) is shared with a receiving node (eg, a base station), the receiving node may transmit a downlink signal in a gap period. For this operation, the terminal may transmit information indicating whether the COT initiated by itself is shared with the base station to the base station through signaling. For example, information indicating whether the COT initiated by the terminal is shared with the base station may be included in UCI (uplink control information), and the UCI may be transmitted from the terminal to the base station. The UE may map the UCI to a partial region or the entire region of the configuration grant resource(s), and transmit the UCI to the base station together with the PUSCH by the configuration grant. Alternatively, the terminal may transmit the above-described UCI to the base station as part of the PUSCH by the configuration grant. That is, the UCI can be piggybacked on the PUSCH.

In addition, the terminal may inform the base station of an interval in which the base station can transmit a downlink signal (hereinafter referred to as a "downlink interval") within the COT initiated by it. The configuration information of the downlink period may be included in the UCI, and the corresponding UCI may be transmitted from the terminal to the base station. In addition, UCI including downlink period configuration information may be piggybacked on PUSCH. The configuration information of the downlink section includes at least one of information indicating whether the COT initiated by the terminal is shared with the base station, the start time of the downlink section, the end time of the downlink section, and the length of the downlink section. can do. The base station may receive configuration information of the downlink period from the terminal, and may determine whether the COT initiated by the terminal is shared with the base station based on the configuration information of the downlink period. The downlink period in the COT initiated by the terminal may be set in units of symbols or slots. That is, the downlink period may include X symbol(s) and/or Y slot(s).

6 is a conceptual diagram illustrating a first embodiment of a method for setting a downlink period in a COT initiated by a terminal.

Referring to FIG. 6, a UE may discontinuously transmit a first uplink transmission burst and a second uplink transmission burst within a COT initiated by the UE. That is, in the time domain, the first uplink transmission burst may be discontinuous from the second uplink transmission burst. The terminal may set a partial region or the entire region of the gap interval between the first uplink transmission burst and the second uplink transmission burst as the downlink interval, and transmit configuration information of the downlink interval to the base station. The downlink period may be used for downlink transmission. In this case, a gap period for LBT operation (eg, a potential gap period) may exist between the first uplink transmission burst and the downlink period, and the downlink period and the second uplink transmission burst There may be a gap period (eg, a potential gap period) for the LBT operation therebetween.

In order to ensure continuous signal transmission in the entire time interval within the COT initiated by the terminal (for example, a time interval excluding the interval for LBT operation within the COT), the base station downlinks in the entire downlink interval set by the terminal. It may have to be guaranteed to transmit the link signal. This operation can be implemented by the following embodiments.

[Downlink communication method within COT]

As a first method, a location of a time resource in which a downlink period can be arranged may be limited. This method may be referred to as “method 100”. In the first embodiment of method 100, the base station may transmit configuration information of the time resource domain and/or the frequency resource domain to the terminal, and the time location and/or frequency location of the downlink period are limited within the resource domain set by the base station. Can be. A time resource region in which a downlink period can be allocated (hereinafter referred to as a "downlink resource pool") may be explicitly set. In this case, the downlink resource pool may be composed of a set of symbol(s) and/or a set of slot(s). The downlink resource pool may appear periodically and repeatedly, and the position of the downlink resource pool may be set in the terminal within one period. In addition, the period of the downlink resource pool may be defined in advance. Alternatively, the base station may set the period of the downlink resource pool to the terminal. The downlink resource pool may include symbol(s) for a specific use. Symbol(s) for a specific use are CORESET, a set of search spaces combined with CORESET, or PDCCH monitoring occasion, a channel state information-reference signal (CSI-RS) resource, a positioning reference signal (PRS) resource, a discovery reference signal (DRS). ) A window for reception and measurement, and/or a downlink semi-persistent scheduling (SPS) resource may be configured symbol(s). The base station may inform the terminal of information about symbol(s) for a specific use included in the downlink resource pool.

DRS may refer to a set of signals and channels for initial access of a terminal, cell search, cell selection, radio resource management (RRM) measurement, and/or RRM reporting. The DRS may basically include a synchronization signal/physical broadcast channel (SS/PBCH) block. In addition, the DRS may further include a CORESET (or a PDCCH search space associated with CORESET), a PDSCH, and/or a CSI-RS in addition to the SS/PBCH block. For example, the DRS may include a PDCCH search space set #0 combined with CORESET #0 and CORESET #0. DCI (eg, DCI scheduling a PDSCH including system information block 1 (SIB1)) may be transmitted through a PDCCH candidate in the resource of the PDCCH search space set #0 combined with CORESET #0. The window related to DRS reception and measurement may be an SS/PBCH block measurement timing configuration (SMTC), a radio link monitoring (RLM) measurement window, and/or an RRM measurement window.

When a specific symbol(s) (e.g., a specific symbol(s) belonging to a time resource region set by the base station) is included in the downlink period, the terminal transmits the downlink signal in the specific symbol(s). Can be expected. For example, when the symbol(s) for which CORESET or PDCCH monitoring occasion is set are included in the downlink period, the UE may expect to successfully receive at least one PDCCH from the corresponding symbol(s). Alternatively, when the symbol(s) for which the window for DRS reception and measurement is set is included in the downlink period, the terminal may expect to receive a downlink signal and a channel including DRS from the corresponding symbol(s). Alternatively, when the symbol(s) in which the SPS resource is configured is included in the downlink period, the terminal may expect to receive the PDSCH in the corresponding symbol(s). In addition, the PDSCH may be transmitted in the above-described symbol(s). The PDSCH may be a PDSCH scheduled by a dynamic grant. For example, the base station may transmit the PDSCH to the terminal along with other signals and channels (eg, PDCCH, CSI-RS, DRS, SPS PDSCH, etc.) in the above-described symbol(s) based on a frequency division multiplexing scheme. .

As a second method, the symbol(s) constituting the downlink period may be predefined. Alternatively, the symbol(s) constituting the downlink period may be used for a predetermined purpose. The base station may set a predetermined purpose to the terminal. One or more uses of the symbol(s) constituting the downlink period may be used. This method may be referred to as “method 110”. For example, the UE may assume that the PDCCH monitoring occasion is arranged in part or all of the symbol(s) included in the downlink period, and the PDCCH monitoring operation is performed in the symbol(s) in which the PDCCH monitoring occasion is arranged. Can be done. The base station may preset a CORESET and/or a search space set for a PDCCH monitoring occasion in the terminal. For example, a CORESET may be arranged in each symbol or some symbols of the downlink period, and the duration of the corresponding CORESET may be defined in advance. Alternatively, the base station may set the duration of the corresponding CORESET to the terminal. For example, the duration of the CORESET may be 1 symbol. In addition, the above-described CORESET and/or setting information of the search space set for the PDCCH monitoring occasion disposed in the downlink period (eg, CORESET defined in the technical standard and/or the setting information of the search space set) is It can be signaled to the terminal. According to the above-described method, the location of the PDCCH monitoring occasion may be determined by the UE. That is, the UE may determine the location of the symbol(s) on which the PDCCH monitoring operation is performed by notifying the base station of the location of the downlink period in the COT initiated by the UE.

As a third method, the base station may compulsorily transmit a downlink signal in symbol(s) constituting a downlink period. In this case, the type of a downlink signal, a downlink time resource, a downlink frequency resource, and/or a downlink transmission method may be (implemented) determined by the base station. The type of the downlink signal may be limited to a physical layer signal and a part of a channel. The operation of the base station in the downlink period may be explicitly defined in the technical standard. Alternatively, the base station may inform the terminal of at least one of operations of the base station in the downlink period. For example, the base station may inform the UE of the physical layer signal(s) and channel(s) that the UE can expect to receive in the downlink period through signaling. This method may be referred to as “method 120”.

On the other hand, "when there is no downlink signal and/or data to be transmitted by the base station" or "when the size of the downlink signal and/or data to be transmitted by the base station is small", the terminal may share the COT initiated by itself with the base station. . In addition, the terminal may set a downlink period within the COT, and may transmit configuration information of the downlink period to the base station. This operation may be undesirable from the viewpoint of downlink transmission. However, this operation may be helpful for discontinuous uplink transmission. In order to ensure continuous signal transmission in the downlink period, the base station may transmit a dummy signal in the downlink period. The period in which the base station can transmit the dummy signal may be limited. For example, the base station may transmit a dummy signal in a downlink period within the COT initiated by the terminal. The dummy signal may be a signal randomly generated/transmitted by the base station. The dummy signal may be a dummy signal defined in the technical standard. When a dummy signal is defined in the technical standard, a downlink signal and a channel used for a specific purpose may be used as a dummy signal. For example, PDCCH, PDSCH, DM-RS, CSI-RS, tracking reference signal (TRS), PRS, SS/PBCH block (or at least some signals and/or channels of SS/PBCH blocks), etc., are used as dummy signals. I can. When a dummy signal is defined in the technical standard, the terminal performs operations for receiving a dummy signal (e.g., a blind decoding operation, a reception processing operation according to the result of the blind decoding operation, an RRM/RLM/CSI measurement operation, etc.) Can be done. Alternatively, the terminal only assumes that a dummy signal is transmitted, and may not perform an operation for receiving or measuring a dummy signal.

Alternatively, the terminal can share the COT with the base station only when there is a downlink signal and data to be transmitted by the base station. For this operation, the base station may transmit downlink buffer status information (buffer status report, BSR) to the terminal. The downlink buffer status information may include information on the size of traffic stored in the downlink buffer of the base station. The downlink buffer status information may be defined in a form similar to the uplink buffer status information reported by the terminal to the base station. In addition, for "the purpose of notifying the terminal of the presence of downlink traffic" or "the purpose of sharing the COT initiated by the terminal", the base station is a logical channel identifier (LCID) for downlink traffic transmission, A channel group (logical channel group, LCG), etc. may be informed to the UE. For example, the logical channel identifier and the logical channel group may be transmitted to the terminal through MAC signaling (eg, MAC CE).

The above-described methods may be combined with each other, and combined methods may be used. For example, Method 120 may be combined with Method 100 and/or Method 110, and combined methods may be used. For example, when the resource allocation condition of method 100 is satisfied, method 120 may be used. Method 100 may be combined with method 110, and "Method 100 + Method 110" may be used.

The above-described methods can be used when certain conditions are satisfied. For example, the above-described methods assume that "when uplink transmission is performed after a downlink interval within a COT initiated by a terminal" or "uplink transmission is performed after a downlink interval within a COT initiated by a terminal. Can be used in "if expected". The terminal may transmit information indicating whether to perform uplink transmission to the base station. The size of information indicating whether to perform uplink transmission may be 1 bit. Whether uplink transmission is performed may be determined according to whether the above-described signaling is performed. Information indicating whether to perform uplink transmission may be included in the UCI, and the corresponding UCI may be piggybacked on the PUSCH. The terminal provides information indicating whether to perform uplink transmission, information indicating whether the COT initiated by the terminal is shared with the base station, and configuration information of the downlink section in the COT initiated by the terminal (e.g., Location information) can be transmitted to the base station.

A plurality of downlink intervals may be configured within the COT initiated by the terminal. The terminal may transmit configuration information of a plurality of downlink intervals to the base station. In this case, the above-described methods can be applied to each of the downlink intervals. For example, the methods 100 to 120 may be applied to each of the downlink intervals. The terminal may signal the configuration information (eg, location information) of each downlink period to the base station. Alternatively, the terminal may signal information indicating whether to perform uplink transmission after each downlink period to the base station.

Alternatively, when a plurality of downlink intervals are set/instructed within the COT initiated by the terminal, the above-described methods may be applied to a specific downlink interval(s). For example, the terminal may signal information indicating whether to perform uplink transmission after the last downlink period to the base station. "Whether uplink transmission is performed after the remaining downlink interval(s) excluding the last downlink interval among the plurality of downlink intervals" is determined according to "whether there is another downlink interval after the corresponding downlink interval" I can.

For example, the COT initiated by the terminal may be shared with the base station, and the terminal may transmit configuration information (eg, location information) of each of two downlink periods within the COT to the base station. In this case, the base station can expect to receive an uplink transmission burst after the first downlink interval because the second downlink interval exists in the COT. Information indicating whether to perform uplink transmission after the second downlink period in the COT may be transmitted from the terminal to the base station.

[COT intercept method]

The COT initiated by the terminal may be shared with the base station, and the base station may transmit a downlink signal (eg, PDCCH, PDSCH, CSI-RS, DRS, etc.) in a downlink period within the corresponding COT. The downlink signal may be limited to a downlink signal for a terminal that has initiated (or initiated) a COT shared with the base station. Alternatively, the downlink signal may be a downlink signal for a terminal other than the terminal initiating COT. Alternatively, the downlink signal may include a downlink signal for another terminal as well as a downlink signal for the terminal initiating COT. For example, "when the downlink signal is a signal including control information" or "the downlink signal is a broadcast signal (eg, a PDSCH including system information and/or a PDCCH corresponding to the PDSCH, a group common PDCCH Etc.)", the downlink signal may be transmitted not only to the terminal that started the COT, but also to other terminals.

7A is a conceptual diagram showing a first embodiment of a method for transmitting a downlink signal within a COT initiated by a terminal, and FIG. 7B is a second embodiment of a method for transmitting a downlink signal within a COT initiated by a terminal It is a conceptual diagram, and FIG. 7C is a conceptual diagram illustrating a third embodiment of a method for transmitting a downlink signal in a COT initiated by a terminal.

7A to 7C, a configured grant (CG) PUSCH may be a PUSCH scheduled by a configuration grant, and a dynamic grant (DG) PUSCH may be a PUSCH scheduled by a dynamic grant. In the embodiment shown in Figure 7a, the COT disclosed in the terminal may be shared with the base station, and the base station may transmit a downlink signal (eg, PDCCH, PDSCH, CSI-RS, etc.) in a downlink period within the COT. have. The downlink signal transmitted in the downlink period within the COT may be a downlink signal for the terminal and/or other terminal that started the corresponding COT.

In addition, the terminal may transmit an uplink transmission burst to the base station after the downlink period within the COT. In this case, the uplink transmission burst may include a CG PUSCH (eg, a PUSCH scheduled by a configuration grant). Alternatively, the uplink transmission burst may include other uplink signals (eg, PUSCH by dynamic grant) in addition to the PUSCH by the configuration grant.

In the embodiments shown in FIGS. 7B and 7C, the UE can transmit the first uplink transmission burst in the COT, and the base station can transmit the downlink transmission burst in the downlink section after the first uplink transmission burst. In addition, the UE may transmit a second uplink transmission burst after the downlink transmission burst. In the embodiment shown in FIG. 7B, the second uplink transmission burst may include a CG PUSCH (eg, a PUSCH based on a configuration grant). When the interval in which the second uplink transmission burst is to be transmitted is set as the configuration grant resource, the terminal may continuously transmit the PUSCH by one or more configuration grants. In this case, the terminal (eg, the terminal initiating the COT) may not expect to receive an uplink grant for scheduling the PUSCH in the previous downlink period within the COT initiated by the terminal.

In the embodiment shown in FIG. 7C, the second uplink transmission burst may include a PUSCH and/or another uplink signal according to a configuration grant. For example, the UE may transmit a PUSCH based on a dynamic grant or a PUSCH based on dynamic scheduling in the second uplink transmission burst. Here, the terminal may be a terminal initiating COT. The terminal may receive the dynamic grant (eg, uplink DCI) in the previous downlink period within the COT initiated by the terminal. The base station transmits information on the LBT operation performed for transmission of the PUSCH (or transmission of the second uplink transmission burst) (e.g., LBT type or category, LBT gap or time gap with the previous transmission, etc.) to the terminal. Can be set or directed. The terminal may obtain information on an LBT operation performed for transmission of the PUSCH (or transmission of a second uplink transmission burst) from the base station. The information on the LBT operation may be included in a dynamic grant (eg, uplink DCI) scheduling the PUSCH, and a dynamic grant including information on the LBT operation may be transmitted to the terminal. The LBT type or category may include at least one of a first, second, third, and fourth category LBT. In addition, the base station may set or instruct the terminal with information on a channel access priority class (CAPC) for the PUSCH. The terminal may obtain information on the channel access priority class for the PUSCH from the base station. The information on the channel access priority class may be included in a dynamic grant (e.g., uplink DCI) for scheduling the PUSCH, and a dynamic grant including information on the channel access priority class may be transmitted to the terminal. have. The range of the channel access priority class may be determined by the channel access priority class used by the terminal to perform the LBT operation for initiating the COT. For example, the channel access priority class may not have a higher priority than the channel access priority class used by the terminal to perform an LBT operation to initiate the COT. When the LBT operation is performed according to the channel access priority class, the terminal may determine the size of a contention window for random backoff. The collision window may be referred to as a contention window. Alternatively, the range of the channel access priority class may be determined irrespective of the channel access priority class used by the UE to perform the LBT operation for initiating the COT.

In addition, the UE may transmit the PUCCH in the second uplink transmission burst. The PUCCH may include a HARQ response (eg, HARQ-ACK (acknowledgement)) for the PDSCH. Here, the PDSCH may be a PDSCH received in the (previous) downlink period(s) within the COT (eg, the same COT) initiated by the UE. Alternatively, the PDSCH may be a PDSCH received before the COT initiated by the terminal. The PDSCH may be a PDSCH based on a dynamic grant. Alternatively, the PDSCH may be a PDSCH by downlink SPS. PUCCH may include a CSI report, a beam measurement report, and/or a scheduling request. Each of the CSI report and the beam measurement report will include aperiodic measurement information for the CSI-RS and/or DRS received in the (previous) downlink period(s) within the COT (e.g., the same COT) initiated by the UE. I can. PUCCH transmission may be triggered by a dynamic grant (eg, downlink DCI, uplink DCI, group common DCI).

When the base station obtains the uplink buffer status information from the terminal, the embodiment shown in FIG. 7C may be more effective than the embodiment shown in FIG. 7B. When the base station knows the buffer state of the terminal, the dynamic grant-based PUSCH transmission by scheduling of the base station may be more efficient than the configuration grant-based PUSCH transmission. For this operation, the UE may transmit a PUSCH (eg, CG PUSCH) including buffer status information within the COT initiated by the UE. The PUSCH including the buffer status information may be transmitted within the first uplink transmission burst. In addition, the buffer status information may be included in one or more PUSCHs in the first uplink transmission burst. One or more PUSCHs including the buffer status information may be PUSCHs (eg, K PUSCHs) from the first PUSCH to the K-th PUSCH in the first uplink transmission burst. K can be 1.

In the embodiment shown in FIG. 7C, when the second uplink transmission burst interval includes a configuration grant resource, the terminal CG within an uplink transmission burst interval (eg, a configuration grant resource in an uplink transmission burst interval). It is possible to transmit not only the PUSCH but also other uplink signals. For example, the UE may transmit a PUSCH (eg, a dynamic grant-based PUSCH), a PUCCH, an SRS, a PRACH, and the like by using the set grant resource in the COT. In this case, the priority of other uplink signals may be considered to be higher than the priority of the CG PUSCH. For example, the priority of uplink transmission by the dynamic grant (eg, PUSCH, PUCCH, SRS, etc. by the dynamic grant) may be higher than the priority of the PUSCH by the configuration grant. The transmission operation of an uplink signal (eg, an uplink signal having a higher priority than that of the CG PUSCH) may be performed according to an instruction or configuration of the base station.

The base station transmits "information indicating the above-described transmission operation of the uplink signal" or "the above-described configuration information of the transmission operation of the uplink signal" to the terminal in the downlink section within the same COT (eg, a COT initiated by the terminal). Can be transferred to. When the COT initiated by the terminal is shared with the base station, the base station transmits control information to the terminal in the downlink interval within the same COT (e.g., COT initiated by the terminal), so that the rest of the COT (e.g., downlink A part or all of the interval (indicated/set as the interval, uplink interval) may be used as intended by the base station. That is, when the COT initiated by the terminal is shared with the base station, the base station may intercept the corresponding COT, and some or all of the remaining intervals of the corresponding COT may be used together with the COT initiated by the base station.

In the embodiment shown in Fig. 7c, the base station is "information indicating the end point of the COT initiated by the terminal" or "information indicating whether the time interval for scheduling the uplink transmission belongs to the COT initiated by the terminal" May not be received from the terminal. In this case, the base station can schedule uplink transmission regardless of whether the time interval in which it schedules uplink transmission belongs to the COT initiated by the terminal. Alternatively, the base station may obtain "information indicating the end point of the COT initiated by the terminal" or "information indicating whether the time interval for scheduling the uplink transmission belongs to the COT initiated by the terminal" from the terminal. . The information may be included in the UCI, and the UCI may be transmitted to the base station together with the PUSCH or separately from the PUSCH. In this case, the base station may schedule uplink transmission based on whether the time interval in which it schedules uplink transmission belongs to the COT initiated by the terminal. For example, the above-described method of determining transmission priority, LBT operation, channel access priority class, etc. may be applied only when the time period in which uplink transmission is scheduled belongs to the COT initiated by the UE.

The base station may selectively perform the embodiment shown in Fig. 7B and the embodiment shown in Fig. 7C. When the COT initiated by the terminal is shared with the base station, the base station can instruct or configure that the terminal transmits an uplink signal in the uplink interval after the downlink interval by transmitting a control message to the terminal in the downlink interval within the corresponding COT. have. The terminal may transmit an uplink signal according to the instruction or configuration of the base station. In this case, the UE may not transmit the PUSCH according to the configuration grant in the uplink period. Alternatively, the UE may transmit a PUSCH according to the configuration grant in a period in which transmission of an uplink signal is not indicated/configured during an uplink period.

Alternatively, the base station may signal information indicating whether the CG PUSCH can be transmitted in the uplink period (eg, the uplink period in the COT initiated by the terminal) to the terminal. Alternatively, the base station may signal to the terminal information instructing to release the configuration grant resource set in the terminal in the uplink period (eg, the uplink period in the COT initiated by the terminal). Alternatively, when the COT initiated by the terminal is shared with the base station, the base station may signal information indicating whether the corresponding COT is intercepted to the terminal. The UE may determine whether CG PUSCH can be transmitted in an uplink period through one or more of the above-described signaling methods, and may perform an uplink operation according to the determination result.

The above-described embodiments can be generalized as a case where a plurality of downlink intervals exist in the COT initiated by the terminal. In this case, an uplink transmission burst (or uplink interval) may exist after each downlink interval. Whether or not there is an uplink transmission burst after the last downlink interval may be determined according to the arrangement of the downlink interval(s) set by the terminal. In this case, the signaling method of the base station and the transmission method of a control message (eg, control information) applied to the above-described embodiments may be applied to each downlink period or any downlink period in the COT. In addition, the uplink transmission method of the terminal applied to the above-described embodiments may be applied to the uplink transmission burst(s) or the uplink period(s) after the first downlink period in the COT.

[Early discontinuation of COT]

8 is a conceptual diagram illustrating a fourth embodiment of a method for transmitting a downlink signal in a COT initiated by a terminal.

Referring to FIG. 8, the terminal may set a predetermined time interval in the COT initiated by itself as a downlink interval, and transmit indication information (eg, configuration information) of the downlink interval to the base station. "When there is no downlink signal and data to be transmitted to the terminal initiating the COT" or "When the size of the downlink signal and data to be transmitted to the terminal initiating the COT is small", a part of the downlink period initiates the COT It may be unnecessary for downlink transmission of the terminal. In this case, the base station transmits at least some downlink signals (e.g., a PDSCH including terminal-specific data or unicast information and/or a PDCCH corresponding to the PDSCH) only to the terminal that initiated the COT in the downlink period. It can be assumed to be capable. According to the above assumption, even when a downlink signal and data to be transmitted to a terminal other than the terminal initiating the COT exists in the base station, the base station may not use a part of the downlink period for downlink transmission. Accordingly, an unused period may occur within the downlink period, and the resource utilization rate may decrease.

As a method for solving the above-described problem, when the COT initiated by the terminal is shared with the base station, the base station may early terminate the corresponding COT. Specifically, the base station may perform an LBT operation in a downlink period within a COT shared with the terminal, and may transmit a downlink transmission burst by accessing a channel when the LBT operation is successful. This operation may be referred to as “method 200”. The LBT operation performed in the method 200 may be a separate LBT operation different from the LBT operation performed by the base station immediately before or at the beginning of the downlink interval in order to acquire the downlink interval.

The channel access operation (eg, LBT operation) performed in the method 200 may be a random backoff-based LBT operation (eg, LBT category 3 or LBT category 4). When the downlink transmission burst to be transmitted through the LBT operation includes short control signaling (eg, DRS), the LBT operation may be an LBT operation without random backoff (eg, LBT category 2). The channel access operation (eg, LBT operation) performed in the method 200 may not be distinguished from the channel access operation performed in a section outside the COT initiated by the terminal. In addition, in method 200, the downlink transmission burst is distinguished from the downlink transmission burst (e.g., a downlink transmission burst belonging to the COT initiated by the terminal) transmitted according to the LBT operation performed immediately before or at the beginning of the downlink period. Can be.

Method 200 may be used when there is no uplink transmission burst or uplink period after the downlink period. Alternatively, method 200 may be used when the downlink period is arranged at the last part of the COT. The UE may signal to the base station information indicating whether there is an uplink transmission burst after the downlink period and/or information indicating whether the downlink period is arranged at the last part of the COT. The base station may receive information indicating whether an uplink transmission burst exists and/or information indicating whether a downlink period is arranged at the last part of the COT from the terminal.

9 is a conceptual diagram illustrating a first embodiment of a method of early stopping COT initiated by a terminal.

Referring to FIG. 9, the first terminal may acquire a COT by successfully performing an LBT operation, and may transmit a PUSCH (eg, CG PUSCH) within the COT. In addition, the first terminal may share the COT initiated by itself with the base station, and may transmit configuration information (eg, indication information) of a downlink period in the corresponding COT to the base station. The base station can check the downlink section in the COT based on the configuration information received from the terminal. The base station may perform the first LBT operation immediately before or at the beginning of the downlink interval, and when the first LBT operation is successful, the PDCCH and PDSCH for the first terminal and/or other terminals at the beginning of the downlink interval Can send. In addition, when there is no downlink signal and data to be transmitted to the first terminal, the base station may perform method 200. For example, the base station may stop the COT shared with the terminal during the downlink period.

Specifically, the base station may perform a second LBT operation within a downlink period. When the second LBT operation is successful, the base station may transmit a new downlink transmission burst before the end of the downlink period. The new downlink transmission burst may include a signal (eg, PDCCH, PDSCH, CSI-RS, etc.) for a terminal other than the first terminal (ie, the second terminal). For example, each of the PDSCH and/or PDCCH for a terminal other than the first terminal (ie, the second terminal) included in the new downlink transmission burst is a PDSCH including terminal-specific data or unicast information and/or It may be a PDCCH corresponding to the corresponding PDSCH. Alternatively, the new downlink transmission burst may include a signal (eg, DRS) for a terminal group. An initial downlink (DL) signal may be arranged at the beginning of a new downlink transmission burst. The UE can confirm a new downlink transmission burst by successfully detecting the downlink initial signal, and the reception operation for the new downlink transmission burst (eg, PDCCH monitoring operation) and the transmission operation within the COT initiated by the base station Can be done. In particular, when the downlink initial signal is successfully detected, the first terminal may determine that the base station has stopped the COT initiated by the first terminal early.

Various downlink signals and channels can be used as downlink initial signals. For example, the DM-RS for demodulation of the PDCCH (hereinafter referred to as "PDCCH DM-RS") may be used as an initial downlink signal. Alternatively, the CORESET broadband DM-RS may be used as a downlink initial signal. In this case, the wideband DM-RS may not be used for demodulation of the PDCCH. Alternatively, a DM-RS for demodulation of the group common PDCCH (hereinafter referred to as “group common PDCCH DM-RS”) may be used as a downlink initial signal. Alternatively, the control information included in the group common PDCCH DM-RS and the group common PDCCH may be used as a downlink initial signal. Alternatively, the broadband DM-RS for demodulation of the group common PDCCH (hereinafter referred to as “group common PDCCH broadband DM-RS”) and control information included in the group common PDCCH may be used as a downlink initial signal. In this case, when the group common DCI is successfully received (eg, when the cyclic redundancy check (CRC) of the group common DCI is successful), the terminal may detect a downlink transmission burst. Alternatively, the CSI-RS may be used as a downlink initial signal.

The group common PDCCH may include a specific DCI format. Control information included in the group common PDCCH may correspond to a payload of a specific DCI format. For example, in an NR communication system, the group common PDCCH may include "DCI format 2_0" or "DCI format modified (or extended) from DCI format 2_0". The DCI format may include information about the COT initiated by the base station (eg, COT configuration information). The above-described operations can be applied even when the group common PDCCH is used.

The terminal is a group common PDCCH (e.g., DCI format 2_0) or control information included in the group common PDCCH (e.g., SFI included in DCI format 2_0, information about the COT duration or COT end time, available (available) Alternatively, a new downlink transmission burst may be identified by successfully detecting information indicating unavailable LBT subband(s), information indicating switching of a search space set, and the like. The terminal may perform a reception operation for a new downlink transmission burst (eg, a PDCCH monitoring operation) and a transmission operation within a COT initiated by the base station.

When method 200 is used, according to a signal and/or channel that the UE considers as a downlink initial signal, it is possible to distinguish the downlink initial signal transmitted in the downlink period within the COT from the general PDCCH and/or PDCCH DM-RS. It can be difficult. For example, when the PDCCH DM-RS is used as the downlink initial signal, it is difficult for the first terminal to distinguish between the PDCCH received in the COT initiated by the first terminal and the PDCCH received in the COT newly initiated by the base station. I can. For another example, when the group common PDCCH DM-RS is used as the downlink initial signal, the first terminal is in the group common PDCCH DM-RS received in the COT initiated by the first terminal and the COT newly initiated by the base station. It may be difficult to distinguish a PDCCH DM-RS (eg, an initial downlink signal) received from. In this case, even when the base station starts transmitting a new downlink transmission burst in the downlink period, the terminal may not recognize that the base station has stopped COT early.

As a method for solving the above problem, "Group common PDCCH DM-RS", "Group common PDCCH broadband DM-RS", "Group common PDCCH control information", "Group common PDCCH DM-RS + group common Control information included in the PDCCH", or "group common PDCCH wideband DM-RS + control information included in the group common PDCCH" may be used as a downlink initial signal. "Group common PDCCH DM-RS", "group common PDCCH broadband DM-RS", "control information included in group common PDCCH", "group common PDCCH DM-RS + group common" in the downlink period in the COT initiated by the terminal When the control information included in the PDCCH" or "control information included in the group common PDCCH broadband DM-RS + group common PDCCH" is successfully detected, the terminal transmits the detected signal to the downlink of the COT newly initiated by the base station. It can be considered an initial signal.

When the downlink initial signal includes a group common PDCCH DM-RS or a group common PDCCH wideband DM-RS (e.g., when the downlink initial signal does not include control information included in the group common PDCCH), group common The initialization function or polynomial for generating each sequence of the PDCCH DM-RS and the group common PDCCH wideband DM-RS may be cell specific, and the sequence may be commonly applied to the PDCCH transmitted from the CSS set as well as the group common PDCCH. . For example, the sequence may be a function of a physical layer cell ID, a slot index, and a symbol index. The sequence may not be a function of the UE-specific identifier (eg, C-RNTI). In this case, when the PDCCH DM-RS or PDCCH wideband DM-RS is successfully detected in the CSS set belonging to the downlink section in the COT initiated by the terminal, the terminal uses the detected PDCCH DM-RS or PDCCH wideband DM-RS to the base station. It can be regarded as a downlink initial signal of a COT newly initiated by.

As another method for solving the above-described problem, the terminal is a specific signal (e.g., group common PDCCH, DCI format 2_0) or information contained in a specific signal (e.g., DCI format 2_0) in the downlink period in the COT. To receive the included SFI, information on the COT duration or COT end point, information indicating available or unavailable LBT subband(s), information indicating switching of a search space set, etc.) In this case, the transmission of the specific signal or the specific signal may be regarded as belonging to a COT or a downlink transmission burst newly initiated by the base station. Accordingly, the UE may perform a reception operation (eg, a PDCCH monitoring operation) for a new downlink transmission burst and a transmission operation within a COT initiated by the base station.

As another method for solving the above-described problem, the base station may inform the terminal that a new COT has been initiated in a downlink section within a COT shared with the terminal (eg, a COT initiated by the terminal). The information may be transmitted to the terminal by an explicit method or an implicit method. The information may be included in the DCI, and the DCI including the information may be transmitted to the terminal through a PDCCH (eg, a group common PDCCH, a PDCCH including scheduling information of a PDSCH/PUSCH).

[Relationship between COT and DRS]

10A is a conceptual diagram illustrating a first embodiment of a channel occupancy method of a terminal in consideration of a DRS-related window, and FIG. 10B is a conceptual diagram illustrating a second embodiment of a channel occupation method of a terminal in consideration of a DRS-related window.

10A and 10B, configuration grant resources (eg, CG resources) set in the terminal may overlap with a window related to DRS reception and measurement (hereinafter, referred to as “DRS related window”). In this case, in the embodiment shown in FIG. 10A, the DRS related window may not be included in the COT initiated by the terminal. For example, the terminal may release the COT initiated by itself before the start of the DRS related window.

Alternatively, in the embodiment shown in FIG. 10B, some or all of the DRS related window may be included in the COT initiated by the terminal. The terminal may perform a DRS reception and measurement operation in a DRS-related window belonging to the COT initiated by it. In addition, when the COT initiated by the terminal is shared with the base station, the base station may transmit a DRS within the corresponding COT. For this operation, the UE may configure a downlink interval in the COT to include a DRS-related window, and transmit configuration information (or indication information) of the corresponding downlink interval to the base station. In addition, the terminal may transmit an uplink signal after the DRS-related window based on the above-described methods.

[PDCCH monitoring operation in COT]

In the downlink period in the COT initiated by the terminal, the base station may transmit the PDCCH and the PDSCH. In this case, in order to support the operation of continuously transmitting a signal in the downlink period, the terminal is configured with a short period or a short interval (e.g., an interval shorter than one slot, 10 or less symbols) It may be advantageous to perform the PDCCH monitoring operation. On the other hand, in order to support continuous transmission of the base station within the COT initiated by the base station, it would be sufficient for the terminal to perform the PDCCH monitoring operation at a relatively long period or a long interval (eg, one slot, a plurality of slots). I can. Due to this operation, power consumption of the terminal can be reduced.

The PDCCH monitoring operation within the COT initiated by the UE may be different from the PDCCH monitoring operation within the COT initiated by the base station. For this operation, the base station may set a CORESET and/or search space set for the COT initiated by the terminal different from the CORESET and/or search space set for the COT initiated by the base station. The base station may independently set each of "CORESET and/or search space set for COT initiated by the terminal" and "CORESET and/or search space set for COT initiated by the base station" in the terminal. For example, for a COT initiated by the terminal, one or more search space sets associated with a common CORESET may be set in the terminal, and for a COT initiated by the base station, one or more search space sets associated with a common CORESET may be set in the terminal. have. One or more search space sets for the COT initiated by the terminal may be set independently from the one or more search space sets for the COT initiated by the base station.

When the method 200 is used, the COT initiated by the terminal may be terminated early by the base station. For example, the base station may early terminate the corresponding COT during the downlink period in the COT initiated by the terminal. In this case, the UE may dynamically change the PDCCH monitoring operation in the downlink period within the COT initiated by the UE. For example, the UE may perform a PDCCH monitoring operation according to the setting of a search space set for a COT initiated by the UE in a corresponding downlink section, and when a COT initiated by a base station is detected in the downlink section ( For example, when a downlink initial signal is detected) from the detection time of the COT initiated by the base station (e.g., the detection time of the downlink initial signal) according to the setting of the search space set for the COT initiated by the base station PDCCH monitoring operation can be performed.

The above-described PDCCH monitoring operation can be applied only to the terminal initiating the COT. Alternatively, the above-described PDCCH monitoring operation may be applied to a plurality of terminals (eg, a terminal initiating a COT and/or other terminal(s)). Whether to apply the above-described PDCCH monitoring operation may be set in the terminal or in the terminal group.

[COT multiplexing method]

When unlicensed band communication is performed, a plurality of terminals belonging to one serving cell can simultaneously access the same channel.

11A is a conceptual diagram showing a first embodiment in which a plurality of terminals simultaneously access the same channel, and FIG. 11B is a conceptual diagram showing a second embodiment in which a plurality of terminals simultaneously access the same channel.

Referring to FIG. 11A, a plurality of terminals (eg, a first terminal, a second terminal) can acquire a COT by successfully performing an LBT operation at the same time, and transmit an uplink transmission burst at the same time within the COT. can do. In this case, the area where the first terminal is located may be geographically close to the area where the second terminal is located. Alternatively, the area where the first terminal is located may be geographically far from the area where the second terminal is located.

Referring to FIG. 11B, a plurality of terminals may acquire a COT by successfully performing an LBT operation at different times, and may transmit an uplink transmission burst at the same time within the COT. In this case, the area where the first terminal is located may be geographically far from the area where the second terminal is located. From the viewpoint of the first terminal, the second terminal may be a hidden node, and from the viewpoint of the second terminal, the first terminal may be a hidden node.

Even when a plurality of terminals belonging to one serving cell perform uplink transmission at the same time, there may be no particular problem in terms of uplink transmission. For example, different interlaces may be allocated to a plurality of terminals, and a plurality of terminals may transmit uplink signals using different interlaces. Interlaces allocated to a plurality of terminals may be allocated to different resources in the frequency domain. In this case, even when a plurality of terminals transmit uplink signals at the same time, the base station can normally receive the uplink signals of the plurality of terminals because the corresponding uplink signals are multiplexed in the frequency domain.

When a downlink interval is set in at least one COT among a plurality of COTs started by a plurality of terminals, the downlink interval in the COT may be an uplink interval in the COT initiated by another terminal. That is, overlap (or collision) between uplink and downlink may occur in a plurality of COTs. For example, in the embodiments shown in FIGS. 11A and 11B, the downlink section of the COT initiated by the first terminal may collide with the uplink section of the COT initiated by the second terminal. In particular, when CCA is omitted for transmission in the downlink period of the COT initiated by the first terminal (eg, transmission of a downlink transmission burst) (eg, when the first category LBT is performed), Transmission collisions may actually occur between the downlink period of the COT initiated by the first terminal and the uplink period of the COT initiated by the second terminal.

When the uplink section overlaps the downlink section in COTs initiated by different terminals, the base station may selectively perform one of an uplink reception operation and a downlink transmission operation in the overlapping section. The base station may recognize the overlap between the uplink period and the downlink period, and may selectively perform an uplink operation and a downlink operation. On the other hand, it may be difficult for the terminal to know whether there is a COT initiated by another terminal. Accordingly, when an uplink period overlaps a downlink period in a plurality of COTs, the base station may perform an uplink reception operation in the overlapping period. Alternatively, the base station may perform a downlink transmission operation in an overlapping period. Or, the base station is the transmission priority of the uplink period (e.g., the priority of the COT to which the uplink period belongs, the transmission priority of the signal(s) and channel(s) transmitted in the uplink period) and the downlink period Transmission priority (e.g., the priority of the COT to which the downlink section belongs, the transmission priority of the signal(s) and channel(s) to be transmitted in the downlink section) can be compared, and An operation corresponding to the section (or COT) may be performed. Alternatively, the base station may self-determine the transmission priority between the uplink period and the downlink period, and perform transmission according to the determined transmission priority. The operation of determining the priority may be performed dynamically. Alternatively, the priority determination operation may be semi-fixedly performed. The information on the above-described transmission priority may be signaled from the base station to the terminal.

Here, the priority of the COT may mean a channel access priority class used to acquire the COT, a signal(s) constituting the COT, and a transmission priority of the channel(s). In addition, the transmission priority of the signal(s) and channel(s) is the transmission priority identified in the upper layer (e.g., the priority of the logical channel, the quality of service (QoS), etc.), the physical layer. It may mean a transmission priority identified in. The transmission priority identified in the physical layer may mean a transmission priority given to a physical signal and a channel, and when transmission of physical signal(s) and channel(s) having different priorities overlap, high priority Physical signal(s) and channel(s) having a priority may be transmitted preferentially, and a physical signal(s) and channel(s) having a lower priority may be omitted. Alternatively, the physical signal(s) and channel(s) having a low priority may be multiplexed to the physical signal(s) and the channel(s) having a high priority, and the physical signal(s) having a low priority and The channel(s) may be transmitted together with the physical signal(s) and channel(s) having a high priority. For example, the transmission priority identified in the physical layer may consist of two stages (eg, a first priority and a second priority). The priority may be transmitted to the UE by an explicit method or an implicit method through physical layer signaling (e.g., a specific field value of DCI, RNTI scrambled in CRC of PDCCH, search space set, etc.).

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)

As a method of operating a terminal in a communication system,
Acquiring a time interval for occupying a channel by performing a listen before talk (LBT) operation;
Transmitting a first uplink signal to a base station in a first uplink period within the time period;
Receiving, from the base station, downlink control information (DCI) including an uplink grant in a downlink interval within the time interval; And
And transmitting a second uplink signal to the base station in a second uplink period indicated by the uplink grant within the time period. The method according to claim 1,
The second uplink period is located after the downlink period and falls within the time period. The method according to claim 1,
Information indicating the end time of the time period or information indicating whether the second uplink period belongs to the time period is transmitted from the terminal to the base station. The method according to claim 1,
The time interval initiated by the terminal is shared with the base station, and configuration information of the downlink interval is transmitted from the terminal to the base station. The method according to claim 1,
The transmission resource of the second uplink signal overlaps with the transmission resource of a physical uplink shared channel (PUSCH) indicated by a configured grant, and the PUSCH indicated by the configuration grant is not transmitted. . The method according to claim 1,
An LBT operation for transmission of the second uplink signal is performed, and information indicating an LBT operation for transmission of the second uplink signal is transmitted from the base station to the terminal. The method according to claim 1,
The second uplink signal includes one or more of PUSCH, a physical uplink control channel (PUCCH), and a sounding reference signal (SRS), and the PUCCH is HARQ for a physical downlink shared channel (PDSCH) received from the base station ( Hybrid automatic repeat request) response, channel state information (CSI), downlink received signal strength measurement information, and a scheduling request (scheduling request) including one or more of the operation method of the terminal. As a method of operating a base station in a communication system,
Receiving a first uplink signal from the terminal in a first uplink interval within a time interval initiated by the terminal;
Transmitting downlink control information (DCI) including an uplink grant to the terminal in a downlink interval within the time interval; And
And receiving a second uplink signal from the terminal in a second uplink period indicated by the uplink grant within the time period. The method of claim 8,
The second uplink period is located after the downlink period and falls within the time period. The method of claim 8,
Information indicating an end point of the time period or information indicating whether the second uplink period belongs to the time period is received from the terminal. The method of claim 8,
The time period is shared with the base station, and configuration information of the downlink period is received from the terminal. The method of claim 8,
The transmission resource of the second uplink signal overlaps with the transmission resource of a physical uplink shared channel (PUSCH) indicated by a configured grant, and the PUSCH indicated by the configuration grant is not received. . The method of claim 8,
Information indicating whether transmission of a third uplink signal according to the configuration grant is possible in configuration grant resources indicated by a configuration grant after the downlink interval within the time interval is transmitted to the terminal in the downlink interval. , The transmission method of the base station. The method of claim 8,
The second uplink signal includes one or more of PUSCH, a physical uplink control channel (PUCCH), and a sounding reference signal (SRS), and the PUCCH is HARQ for a physical downlink shared channel (PDSCH) transmitted from the base station ( Hybrid automatic repeat request) response, CSI (channel state information), downlink received signal strength measurement information, and a scheduling request (scheduling request) including one or more of the operation method of the base station. As a terminal in a communication system,
Processor;
A memory in electronic communication with the processor; And
Contains instructions stored in the memory,
When the instructions are executed by the processor, the instructions are the terminal,
Acquiring a time interval for occupying a channel by performing a listen before talk (LBT) operation;
Transmitting a first uplink signal to a base station in a first uplink period within the time period;
Receiving from the base station downlink control information (DCI) including an uplink grant in a downlink interval within the time interval; And
A terminal operating to cause transmission of a second uplink signal to the base station in a second uplink period indicated by the uplink grant within the time period. The method of claim 15,
The second uplink period is located after the downlink period and falls within the time period. The method of claim 15,
The time interval initiated by the terminal is shared with the base station, and configuration information of the downlink interval is transmitted from the terminal to the base station. The method of claim 15,
The transmission resource of the second uplink signal overlaps with the transmission resource of a physical uplink shared channel (PUSCH) indicated by a configured grant, and a PUSCH indicated by the configuration grant is not transmitted. The method of claim 18,
Information indicating that the time interval initiated by the terminal is intercepted by the base station is received from the base station in the downlink interval. The method of claim 15,
The second uplink signal includes one or more of PUSCH, a physical uplink control channel (PUCCH), and a sounding reference signal (SRS), and the PUCCH is HARQ for a physical downlink shared channel (PDSCH) received from the base station ( Hybrid automatic repeat request) response, channel state information (CSI), downlink received signal strength measurement information, and a terminal comprising one or more of a scheduling request (scheduling request).

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