Method and apparatus for urllc in unlicensed bands

Abstract

A method and device for URLLC in unlicensed bands are disclosed. An operation method of a terminal includes the steps of: receiving, from a base station, first configuration information of a first FFP for channel access of the terminal and second configuration information of a second FFP for channel access of the base station; initiating a first COT in at least one of the first FFPs indicated by the first configuration information; and determining one COT between the first COT and a second COT according to a predefined rule, wherein the second COT is initiated by the base station in at least one of the second FFPs.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a technology of transmitting and receiving a signal in a communication system, and more particularly, to a technology of transmitting and receiving a signal according to requirements of ultra-reliable low latency communication (URLLC). BACKGROUND

[0002] A communication system (hereinafter, a new radio (NR) communication system) using a higher frequency band (for example, a frequency band of 6 GHz or more) than a frequency band (for example, a frequency band of less than 6 GHz) of long term evolution (LTE) (or LTE-A) is being considered to process rapidly increasing wireless data. The NR communication system can support not only a frequency band of less than 6 GHz 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, usage scenarios of the NR communication system can include enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), massive machine type communication (mMTC), etc. Communication techniques are required to meet the requirements of eMBB, URLLC, and mMTC.

[0003] In addition, in order to process rapidly increasing wireless data, communication using an unlicensed band can be used. Currently, communication techniques using an unlicensed band include NR-unlicensed (NR-U), LTE-unlicensed (LTE-U), licensed assisted access (LAA), MultiFire, etc. The NR-U can support a standalone mode of providing a communication service using only an unlicensed band. There is a need for improving a channel access method and a transmission method to effectively support the above-described usage scenarios (for example, URLLC) in unlicensed band communication. SUMMARY

[0004] TECHNICAL PROBLEM

[0005] An object of the disclosure for solving the above-described problems is to provide a method and apparatus for transmitting and receiving an uplink signal according to requirements of ultra-reliable low latency communication (URLLC).

[0006] TECHNICAL SOLUTION

[0007] An operation method of a terminal according to a first exemplary embodiment of the disclosure for achieving the object can include receiving, from a base station, first configuration information of a first FFP for channel access of the terminal and second configuration information of a second FFP for channel access of the base station, initiating a first COT in at least one of the first FFPs indicated by the first configuration information, determining one COT from among the first COT and a second COT according to a predefined rule, wherein the second COT is initiated by the base station in at least one of the second FFPs, and transmitting an uplink signal to the base station in the one COT.

[0008] Here, a period in which the uplink signal is transmitted can be included in the first COT initiated by the terminal, and the uplink signal can be transmitted based on the first COT.

[0009] Here, the uplink signal can be included in the second COT initiated by the base station, and the first COT can overlap the second COT.

[0010] Here, the uplink signal can be a CG PUSCH, and the uplink signal can be allocated in a period other than a first symbol in the first COT.

[0011] Here, the uplink signal can be one PUSCH constituting a repeated PUSCH transmission or one PUCCH constituting a repeated PUCCH transmission.

[0012] Here, a period in which the uplink signal is transmitted within the first COT can include an idle period of the at least one second FFP to which the second COT belongs.

[0013] Here, the predefined rule can include a rule pre-negotiated between the terminal and the base station or DCI indicating the one COT received from the base station.

[0014] Here, the first configuration information can include information indicating a first period of the first FFP, the second configuration information can include information indicating a second period of the second FFP, and the first period can be an integer resolution or an integer multiple of the second period.

[0015] Here, the first configuration information can include a time offset for the first FFP, the first FFP can be periodically repeated, a position of the first FFP can be determined by the time offset, and the time offset can be a number of symbols between a start time of a radio frame and a start time of one of the first FFPs.

[0016] Here, the number of symbols between the start time of the radio frame and the start time of one of the first FFPs can be less than the number of symbols corresponding to the first period of the first FFP, and the number of symbols between the start time of the radio frame and the start time of one of the first FFPs can be determined based on a numerology of a bandwidth part configured in a carrier.

[0017] Here, the first configuration information and the second configuration information can be included in an RRC message transmitted to the terminal.

[0018] An operation method of a base station according to a second exemplary embodiment of the disclosure to achieve the object can include generating first configuration information of a first FFP for channel access of a terminal and second configuration information of a second FFP for channel access of the base station, transmitting the first configuration information and the second configuration information to the terminal, initiating a second COT in at least one of the second FFPs, and receiving an uplink signal from the terminal in one COT determined from the second COT and a first COT according to a predefined rule, wherein the first COT is initiated by the terminal in at least one of the first FFPs.

[0019] Here, a period in which the uplink signal is transmitted can be included in the first COT initiated by the terminal, and the uplink signal can be received based on the first COT.

[0020] Here, the uplink signal can be included in the second COT initiated by the base station, and the first COT can overlap the second COT.

[0021] Here, the uplink signal can be a CG PUSCH, and the uplink signal can be allocated in a period other than a first symbol in the first COT.

[0022] Here, the uplink signal can be one PUSCH constituting a repeated PUSCH transmission or one PUCCH constituting a repeated PUCCH transmission.

[0023] Here, the predefined rule can include DCI indicating the one COT transmitted by the base station to the terminal or a rule pre-negotiated between the terminal and the base station.

[0024] Here, the first configuration information can include information indicating a first period of the first FFP, the second configuration information can include information indicating a second period of the second FFP, and the first period can be an integer resolution or an integer multiple of the second period.

[0025] Here, the first configuration information can include a time offset for the first FFP, the first FFP can be periodically repeated, a position of the first FFP can be determined by the time offset, and the time offset can be a number of symbols between a start time of a radio frame and a start time of one of the first FFPs.

[0026] Here, the number of symbols between the start time of the radio frame and the start time of one of the first FFPs can be less than a number of symbols corresponding to a first period of the first FFPs, and the number of symbols between the start time of the radio frame and the start time of one of the first FFPs can be determined based on a numerology of a bandwidth part configured in a carrier.

[0027] Advantageous Effects

[0028] According to the disclosure, a base station can allocate a physical uplink shared channel (PUSCH) resource considering a downlink signal processing time. In this case, uncertainty of a PUSCH transmission can be eliminated, and reliability of an uplink transmission can be improved. In addition, a channel occupancy time (COT) of a first communication node (e.g., a terminal) can be terminated in advance to secure a channel sensing operation of a second communication node (e.g., a base station). When a COT of a terminal overlaps with a COT of a base station, an uplink transmission can be performed in one COT determined according to a predefined rule. In this case, reliability of an uplink transmission can be improved, and performance of a communication system can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a conceptual diagram illustrating a first exemplary embodiment of a communication system.

[0030] Figure 2 is a block diagram illustrating a first exemplary embodiment of a communication node constituting a communication system.

[0031] Figure 3a is a conceptual diagram illustrating a first exemplary embodiment of a communication method within a COT.

[0032] Figure 3b is a conceptual diagram illustrating a second exemplary embodiment of a communication method within a COT.

[0033] Figure 4 is a conceptual diagram illustrating a first exemplary embodiment of an FFP configuration method.

[0034] Figure 5 is a conceptual diagram illustrating a first exemplary embodiment of a method for configuring an LBT sub-band and a guard band.

[0035] Figure 6a is a conceptual diagram illustrating a first exemplary embodiment of a method for transmitting a PUSCH in a shared COT.

[0036] Figure 6b is a conceptual diagram illustrating a second exemplary embodiment of a method for transmitting a PUSCH in a shared COT.

[0037] Figure 6c is a conceptual diagram illustrating a third exemplary embodiment of a method for transmitting a PUSCH in a shared COT.

[0038] Figure 6d is a conceptual diagram illustrating a fourth exemplary embodiment of a method for transmitting a PUSCH in a shared COT.

[0039] Figure 7 is a conceptual diagram illustrating an exemplary embodiment of a method for repeatedly transmitting a PUSCH in a shared COT.

[0040] Figure 8 is a conceptual diagram illustrating a first exemplary embodiment of a method for uplink transmission near an FFP boundary.

[0041] Figure 9 is a conceptual diagram illustrating a second exemplary embodiment of a method for uplink transmission near an FFP boundary.

[0042] Figure 10 is a conceptual diagram illustrating an exemplary embodiment of a method for uplink FFP initiation by a terminal.

[0043] Figure 11a is a conceptual diagram illustrating a first exemplary embodiment of a method for configuring a downlink FFP and an uplink FFP.

[0044] Figure 11b is a conceptual diagram illustrating a second exemplary embodiment of a method for configuring a downlink FFP and an uplink FFP.

[0045] Figure 12 is a conceptual diagram illustrating a third exemplary embodiment of a method for uplink transmission near an FFP boundary.

[0046] Figure 13 is a conceptual diagram illustrating a first exemplary embodiment of a channel access method when a downlink FFP and an uplink FFP coexist.

[0047] Figure 14 is a conceptual diagram illustrating a second exemplary embodiment of a channel access method when a downlink FFP and an uplink FFP coexist.

[0048] Figure 15 is a conceptual diagram illustrating a first exemplary embodiment of a channel access method when a downlink FFP and an uplink FFP coexist.

[0049] Figure 16 is a conceptual diagram illustrating a third exemplary embodiment of a channel access method when a downlink FFP and an uplink FFP coexist.

[0050] Figure 17a is a conceptual diagram illustrating a first exemplary embodiment of a signal transmission method in an idle period.

[0051] Figure 17b is a conceptual diagram illustrating a second exemplary embodiment of a signal transmission method in an idle period.

[0052] Figure 18 is a conceptual diagram illustrating a first exemplary embodiment of a channel access method using multiple channels.

[0053] Figure 19 is a conceptual diagram illustrating a first exemplary embodiment of a method for configuring a guard band. DETAILED DESCRIPTION

[0054] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description is not intended to limit the disclosure to the particular embodiments described, but is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

[0055] Although the terms "first", "second", etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure. The term "and / or" includes any or all combinations of one or more of the associated listed items.

[0056] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[0057] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the disclosure. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and / or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0058] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0059] Hereinafter, preferred exemplary embodiments of the disclosure will be described in detail with reference to the accompanying drawings. In describing the disclosure, for the entire understanding, like numbers refer to like elements throughout the description of the figures, and repetitive description thereof will be omitted.

[0060] A communication system to which exemplary embodiments according to the disclosure are applied will be described. The communication system can be a 4G communication system (e.g., a Long Term Evolution (LTE) communication system or an LTE-A communication system), a 5G communication system (e.g., a New Radio (NR) communication system), or the like. The 4G communication system can support communication in a frequency band of 6 GHz or lower, and the 5G communication system can support communication in a frequency band of 6 GHz or higher as well as a frequency band of 6 GHz or lower. The communication system to which exemplary embodiments according to the disclosure are applied is not limited to what is described below, and exemplary embodiments according to the disclosure can be applied to various communication systems. Here, the communication system can use "LTE" in the same sense as a communication network, "LTE" can refer to a "4G communication system," an "LTE communication system," or an "LTE-A communication system," and "NR" can refer to a "5G communication system" or an "NR communication system."

[0061] Figure 1 is a conceptual diagram illustrating a first exemplary embodiment of a communication system.

[0062] Referring to Figure 1The communication system 100 can include 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, and 130-6. In addition, the communication system 100 can further include a core network (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), and a mobile management entity (MME)). When the communication system 100 is a 5G communication system (e.g., a new radio (NR) system), the core network can include an access and mobile management function (AMF), a user plane function (UPF), a session management function (SMF), etc.

[0063] The plurality of communication nodes 110 to 130 can support a communication protocol defined in a 3rd generation partnership project (3GPP) technical specification (e.g., an LTE communication protocol, an LTE-A communication protocol, an NR communication protocol, etc.). The plurality of communication nodes 110 to 130 can support a code division multiple access (CDMA) based communication protocol, a wideband CDMA (WCDMA) based communication protocol, a time division multiple access (TDMA) based communication protocol, a frequency division multiple access (FDMA) based communication protocol, an orthogonal frequency division multiplexing (OFDM) based communication protocol, a filter OFDM based communication protocol, a cyclic prefix OFDM (CP-OFDM) based communication protocol, a discrete Fourier transform-spread-OFDM (DFT-s-OFDM) based communication protocol, an orthogonal frequency division multiple access (OFDMA) based communication protocol, a single carrier FDMA (SC-FDMA) based communication protocol, a non-orthogonal multiple access (NOMA) based communication protocol, a generalized frequency division multiplexing (GFDM) based communication protocol, a filter bank multicarrier (FBMC) based communication protocol, a universal filtered multi-carrier (UFMC) based communication protocol, a spatial division multiple access (SDMA) based communication protocol, etc. Each of the plurality of communication nodes can have the following structure.

[0064] Figure 2 is a block diagram illustrating a first exemplary embodiment of a communication node constituting a communication system.

[0065] Referring to Figure 2 The communication node 200 can include at least one processor 210, a memory 220, and a transceiver 230 connected to a network to perform communication. In addition, the communication node 200 can further include an input interface device 240, an output interface device 250, a storage device 260, etc. Each component included in the communication node 200 can communicate with each other when connected through a bus 270.

[0066] The processor 210 can execute a program stored in at least one of the memory 220 and the storage 260. The processor 210 can refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor performing a method according to an embodiment of the disclosure. Each of the memory 220 and the storage 260 can be constituted by at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 can include at least one of a read-only memory (ROM) and a random access memory (RAM).

[0067] Referring back to Figure 1 , the communication system 100 can include a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and a plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 can form a macro cell, and each of the fourth base station 120-1 and the fifth base station 120-2 can form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 can belong to a cell coverage of the first base station 110-1. Also, the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 can belong to a cell coverage of the second base station 110-2. Also, the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 can belong to a cell coverage of the third base station 110-3. Also, the first terminal 130-1 can belong to a cell coverage of the fourth base station 120-1, and the sixth terminal 130-6 can belong to a cell coverage of the fifth base station 120-2.

[0068] Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be referred to as a NodeB (NB), an evolved-NodeB (eNB), a gNB, an advanced base station (ABS), a high-reliability-base station (HR-BS), a base transceiver station (BTS), a radio base station, a radio transceiver, an access point (AP), an access node, a radio access station (RAS), a mobile multi-hop relay-base station (MMR-BS), a relay station (RS), an advanced relay station (ARS), a high-reliability-relay station (HR-RS), a home NodeB (HNB), a home eNodeB (HeNB), a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), or the like.

[0069] Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can be referred to as a user equipment (UE), a terminal device (TE), an advanced mobile station (AMS), a high reliability-mobile station (HR-MS), a terminal, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, an on-board unit (OBU), etc.

[0070] In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can operate in the same frequency band or different frequency bands. The plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to each other via ideal backhaul links or non-ideal backhaul links, and exchange information with each other via ideal or non-ideal backhaul. Furthermore, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to a 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 can transmit a signal received from the core network to the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6, and transmit a signal received from the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 to the core network.

[0071] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1 and 120-2 can support multiple-input multiple-output (MIMO) transmission (for example, single-user MIMO (SU-MIMO), multi-user MIMO (MU-MIMO), massive MIMO, etc.), coordinated multi-point (CoMP) transmission, carrier aggregation (CA) transmission, transmission in unlicensed frequency bands, device-to-device (D2D) communication (or proximity service (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may perform operations corresponding to the operations of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 (i.e., operations supported by the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2). For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 in SU-MIMO mode, and the fourth terminal 130-4 may receive a signal from the second base station 110-2 in SU-MIMO mode. Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 in MU-MIMO mode, and the fourth terminal 130-4 and the fifth terminal 130-5 may receive a signal from the second base station 110-2 in MU-MIMO mode.

[0072] Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 can transmit a signal to the fourth terminal 130-4 in a CoMP transmission manner, and the fourth terminal 130-4 can receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 in a CoMP manner. In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can exchange signals with the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 within its cell coverage in a CA manner. Each of base stations 110-1, 110-2, and 110-3 may control D2D communication between fourth terminal 130-4 and fifth terminal 130-5, and thus fourth terminal 130-4 and fifth terminal 130-5 may perform D2D communication under the control of second base station 110-2 and third base station 110-3.

[0073] A method of transmitting and receiving a signal in a communication system will be described. Specifically, a channel occupancy method, a signal transmission method, and a channel occupancy-related information transmission method of a communication node (e.g., a base station and / or a terminal) for improving transmission reliability and latency time in a wireless communication system supporting communication in an unlicensed band will be described. The following exemplary embodiments can be applied not only to an NR communication system but also to other communication systems (e.g., an LTE communication system, a fifth generation (5G) communication system, a sixth generation (6G) communication system, etc.).

[0074] An NR communication system can support a system bandwidth (e.g., a carrier bandwidth) wider than that provided by an LTE communication system in order to efficiently use a wide frequency band. For example, the maximum system bandwidth supported by an LTE communication system can be 20 MHz. On the other hand, an NR communication system can support a carrier bandwidth of up to 100 MHz in a frequency band of 6 GHz or lower and a carrier bandwidth of up to 400 MHz in a frequency band of 6 GHz or higher.

[0075] A numerology applied to physical signals and channels in a communication system (e.g., an NR communication system) can be variable. The numerology can vary to meet various technical requirements of the communication system. In a communication system to which a cyclic prefix (CP)-based OFDM waveform technology is applied, the numerology can include a subcarrier spacing and a CP length (or a CP type). Table 1 below can be a first exemplary embodiment of a configuration of numerologies for CP-based OFDM. The subcarrier spacing can have an exponential multiplicative relationship of 2, and the CP length can be scaled at the same rate as the OFDM symbol length. Depending on a frequency band in which the communication system operates, at least some of the numerologies of Table 1 can be supported. Further, in the communication system, numerology(s) not listed in Table 1 can also be supported. For a particular subcarrier spacing (e.g., 60 kHz), a CP type (e.g., an extended CP) not listed in Table 1 can additionally be supported.

[0076] [Table 1]

[0077]

[0078] In the following description, a frame structure in a communication system will be described. In the time domain, elements constituting the frame structure can include a subframe, a slot, a mini-slot, a symbol, etc. The subframe can be used as a unit for transmission, measurement, etc., and the length of the subframe can have a fixed value (e.g., 1 ms) regardless of a subcarrier spacing. The slot can include consecutive symbols (e.g., 14 OFDM symbols). The length of the slot can vary differently from the length of the subframe. For example, the length of the slot can be inversely proportional to the subcarrier spacing.

[0079] A time slot may be used as a unit for transmission, measurement, scheduling, resource configuration, timing (e.g., scheduling timing, hybrid automatic repeat request (HARQ) timing, channel state information (CSI) measurement and reporting timing, etc.). The length of the actual time resources used for transmission, measurement, scheduling, resource configuration, etc. may not match the length of the time slot. A mini-slot may include consecutive symbols, and the length of a mini-slot may be shorter than the length of a time slot. A mini-slot may be used as a unit for transmission, measurement, scheduling, resource configuration, timing, etc. Mini-slots (e.g., the length of mini-slots, mini-slot boundaries, etc.) may be predefined in technical specifications. Optionally, mini-slots (e.g., the length of mini-slots, mini-slot boundaries, etc.) may be configured (or indicated) to the terminal. When specific conditions are met, the use of mini-slots may be configured (or indicated) to the terminal.

[0080] The base station may use some or all of the symbols constituting the time slot to schedule data channels (e.g., physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH), physical sidelink shared channel (PSSCH)). Specifically, for URLLC transmission, unlicensed band transmission, transmission in the case of coexistence of NR communication system and LTE communication system, and multi-user scheduling based on analog beamforming, part of the time slot may be used to send the data channel. In addition, the base station may use multiple time slots to schedule the data channel. In addition, the base station may use at least one mini-time slot to schedule the data channel.

[0081] In the frequency domain, the elements constituting the frame structure may include resource blocks (RBs), subcarriers, etc. One RB may include consecutive subcarriers (e.g., 12 subcarriers). The number of subcarriers constituting one RB may be constant, regardless of the parameter set. In this case, the bandwidth occupied by one RB may be proportional to the subcarrier spacing of the parameter set. RBs may be used as transmission and resource allocation units for data channels, control channels, etc. Resource allocation for data channels may be performed in units of RBs or RB groups (e.g., resource block groups (RBGs)). One RBG may include one or more consecutive RBs. Resource allocation for control channels may be performed in units of control channel elements (CCEs). One CCE in the frequency domain may include one or more RBs.

[0082] In an NR communication system, a slot (e.g., a slot format) can consist of a combination of one or more of a downlink period, a flexible period (or unknown period), and an uplink period. Each of the downlink period, the flexible period, and the uplink period can include one or more consecutive symbols. The flexible period can be located between the downlink period and the uplink period, between a first downlink period and a second downlink period, or between a first uplink period and a second uplink period. When the flexible period is inserted between the downlink period and the uplink period, the flexible period can be used as a guard period.

[0083] A slot can include one or more flexible periods. Alternatively, a slot can not include a flexible period. A terminal can perform a predefined operation in a flexible period. Alternatively, a terminal can perform an operation semi-statically or periodically configured by a base station. For example, an operation periodically configured by a base station can include a PDCCH monitoring operation, a synchronization signal / physical broadcast channel (SS / PBCH) block reception and measurement operation, a channel state information-reference signal (CSI-RS) reception and measurement operation, a 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. When a flexible symbol is overwritten by a downlink or uplink symbol, a terminal can perform a new operation instead of an existing operation in the corresponding flexible symbol (e.g., the overwritten flexible symbol).

[0084] A slot format can be semi-statically configured through higher layer signaling (e.g., radio resource control (RRC) signaling). Information indicating a semi-static slot format can be included in system information, and the semi-static slot format can be configured in a cell-specific manner. In addition, the semi-static slot format can be additionally configured for each terminal through terminal-specific higher layer signaling (e.g., RRC signaling). A flexible symbol of a cell-specifically configured slot format can be overwritten by a downlink symbol or an uplink symbol through terminal-specific higher layer signaling. In addition, a slot format can be dynamically indicated by physical layer signaling (e.g., a slot format indicator (SFI) included in downlink control information (DCI)). A semi-statically configured slot format can be overwritten by a dynamically indicated slot format. For example, a semi-static flexible symbol can be overwritten by a downlink symbol or an uplink symbol through an SFI.

[0085] The terminal can perform downlink operations, uplink operations, and sidelink operations in the bandwidth part. A bandwidth part can be defined as a set of consecutive RBs (e.g., physical resource blocks (PRBs)) with a specific parameter set in the frequency domain. In one bandwidth part, only one parameter set can be used for the transmission of a signal (e.g., transmission of a control channel or a data channel). In an exemplary embodiment, when used in a broad sense, "signal" can refer to any physical signal and channel. A terminal performing an initial access procedure can obtain configuration information of the initial bandwidth part from the base station through system information. A terminal operating in an RRC connected state can obtain configuration information of the bandwidth part from the base station through higher layer signaling specific to the terminal.

[0086] The configuration information of the bandwidth part may include a parameter set applied to the bandwidth part (e.g., subcarrier spacing and CP length). In addition, the configuration information of the bandwidth part may also include information indicating the position of the starting RB (e.g., starting PRB) of the bandwidth part and information indicating the number of RBs (e.g., PRBs) constituting the bandwidth part. At least one bandwidth part among the bandwidth parts configured in the terminal may be activated. For example, within one carrier, one uplink bandwidth part and one downlink bandwidth part may be activated respectively. In a communication system based on time division duplex (TDD), a pair of uplink bandwidth part and downlink bandwidth part may be activated. The base station may configure multiple bandwidth parts for the terminal within one carrier and may switch the activated bandwidth part of the terminal.

[0087] In an exemplary embodiment, the expression "a frequency band (e.g., a carrier, a bandwidth portion, a listen before talk (LBT) sub-band, a guard band, etc.) is activated" may indicate that a base station or a terminal is in a state where the frequency band can transmit or receive signals using the corresponding frequency band. Furthermore, the expression "a frequency band is activated" may indicate that a radio frequency (RF) filter (e.g., a bandpass filter) of a transceiver is operating in a frequency band including the corresponding frequency band (e.g., an activated frequency band).

[0088] In an exemplary embodiment, an RB may represent a common RB (CRB). Alternatively, an RB may represent a PRB or a virtual RB (VRB). In an NR communication system, a CRB may refer to an RB that constitutes a set of continuous RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). Carriers, bandwidth parts, etc. may be arranged on the common RB grid. That is, carriers, bandwidth parts, etc. may be composed of CRBs. The RBs or CRBs constituting the bandwidth part may be referred to as PRBs, and the CRB index within the bandwidth part may be appropriately converted to a PRB index. In an exemplary embodiment, an RB may represent an interleaved RB (IRB). IRBs will be described later.

[0089] A PDCCH can be used to transmit DCI or a DCI format to a terminal. A minimum resource unit constituting a PDCCH can be a resource element group (REG). An REG can consist of one PRB (e.g., 12 subcarriers) in a frequency domain and one OFDM symbol in a time domain. Accordingly, one REG can include 12 resource elements (REs). A demodulation reference signal (DMRS) used to demodulate a PDCCH can be mapped to 3 REs among the 12 REs constituting an REG, and control information (e.g., modulated DCI) can be mapped to the remaining 9 REs.

[0090] One PDCCH candidate can consist of one CCE or aggregated CCEs. One CCE can consist of multiple REGs. An NR communication system can support CCE aggregation levels 1, 2, 4, 8, 16, etc., and one CCE can consist of six REGs.

[0091] A control resource set (CORESET) can be a resource area in which a terminal performs blind decoding of a PDCCH. A CORESET can consist of multiple REGs. A CORESET can consist of one or more PRBs in a frequency domain and one or more symbols (e.g., OFDM symbols) in a time domain. The symbols constituting one CORESET can be consecutive in the time domain. The PRBs constituting one CORESET can be consecutive or non-consecutive in the frequency domain. One DCI (e.g., one DCI format or one PDCCH) can be transmitted within one CORESET. Multiple CORESETs can be configured for a cell and a terminal, and the multiple CORESETs can overlap in time-frequency resources.

[0092] A CORESET can be configured in a terminal through a PBCH (e.g., through system information transmitted by a PBCH). An identifier (ID) of a CORESET configured through a PBCH can be 0. That is, a CORESET configured through a PBCH can be referred to as CORESET#0. A terminal operating in an RRC idle state can perform a monitoring operation in CORESET#0 in order to receive a first PDCCH in an initial access procedure. Not only a terminal operating in an RRC idle state but also a terminal operating in an RRC connected state can perform a monitoring operation in CORESET#0. A CORESET can be configured in a terminal according to other system information (e.g., system information block type 1 (SIB1)) other than system information transmitted through a PBCH. For example, in order to receive a random access response (or Msg2) in a random access procedure, a terminal can receive SIB1 including configuration information of a CORESET. Furthermore, a CORESET can be configured in a terminal through terminal-specific higher layer signaling (e.g., RRC signaling).

[0093] In each downlink bandwidth part, one or more CORESETs can be configured for a terminal. Here, the expression "a CORESET is configured in a bandwidth part" can mean that the CORESET is logically associated with the bandwidth part, and the terminal monitors the corresponding CORESET in the bandwidth part. An initial downlink active bandwidth part can include a CORESET #0, and can be associated with the CORESET #0. A CORESET #0 having a quasi co-location (QCL) relationship with an SS / PBCH block can be configured for a terminal in a primary cell (PCell), a secondary cell (SCell), and a primary secondary cell (PSCell). In a secondary cell (SCell), a CORESET #0 can not be configured for a terminal.

[0094] A search space can be a set of candidate resource areas in which a PDCCH can be transmitted. A terminal can perform blind decoding on each of PDCCH candidates within a predefined search space. The terminal can determine whether a PDCCH is transmitted to itself by performing a cyclic redundancy check (CRC) on a result of the blind decoding. When it is determined that the PDCCH is a PDCCH for the terminal itself, the terminal can receive the PDCCH.

[0095] A PDCCH candidate can be configured with a CCE selected by a predefined hash function within an occasion of a search space or a CORESET. A search space can be defined and configured for each CCE aggregation level. In this case, a set of search spaces for all CCE aggregation levels can be referred to as a "search space set". In an exemplary embodiment, a "search space" can mean a "search space set", and a "search space set" can mean a "search space".

[0096] A search space set can be logically associated with one CORESET. One CORESET can be logically associated with one or more search space sets. A common search space set configured through a PBCH can be used to monitor a DCI scheduling a PDSCH for transmission of a SIB1. An ID of the common search space set configured through the PBCH can be set to 0. That is, the common search space set configured through the PBCH can be defined as a Type 0 PDCCH common search space set or a search space set #0. The search space set #0 can be logically associated with a CORESET #0.

[0097] The search space set can be classified into a common search space set and a terminal-specific (i.e., UE-specific) search space set. A common DCI can be transmitted in the common search space set, and a terminal-specific DCI can be transmitted in the terminal-specific search space set. The terminal-specific DCI can also be transmitted in the common search space set, considering the degree of freedom in scheduling and / or fallback transmission. For example, the common DCI can include resource allocation information for PDSCH for transmission of system information, paging, a power control command, a slot format indicator (SFI), an preemption indicator, etc. The terminal-specific DCI can include PDSCH resource allocation information, PUSCH resource allocation information, etc. A plurality of DCI formats can be defined according to the payload and size of the DCI, the type of radio network temporary identifier (RNTI), etc.

[0098] In an exemplary embodiment, the common search space can be referred to as a "CSS", and the common search space set can be referred to as a "CSS set". Also, in an exemplary embodiment, the terminal-specific search space can be referred to as a "USS", and the terminal-specific search space set can be referred to as a "USS set".

[0099] Exemplary embodiments can be applied to various communication scenarios using unlicensed bands. For example, a cell in an unlicensed band can be configured as a secondary cell with the assistance of a primary cell in a licensed band, and a carrier in the secondary cell can be aggregated with another carrier. Alternatively, a cell (e.g., a secondary cell) in an unlicensed band and a cell (e.g., a primary cell) in a licensed band can support a dual connectivity operation. Accordingly, transmission capacity can be increased. A cell in an unlicensed band can independently perform the function of a primary cell. A downlink carrier of a licensed band can be combined with an uplink carrier of an unlicensed band, and the combined carrier can perform a function as one cell. On the other hand, an uplink carrier of a licensed band can be combined with a downlink carrier of an unlicensed band, and the combined carrier can perform a function as one cell. Also, exemplary embodiments can be applied to other communication systems (e.g., a communication system supporting a licensed band) as well as a communication system supporting an unlicensed band.

[0100] In the communication in the unlicensed band, a contention-based channel access scheme can be used to provide a fair channel usage opportunity to the communication nodes, and a related spectrum regulation condition can be defined. For example, a transmitting node (e.g., a communication node performing a transmitting operation) can identify whether a channel is in a busy state or an idle state by performing a clear channel assessment (CCA) operation. When the channel is in the idle state, the transmitting node can transmit a signal by occupying the corresponding channel for a predetermined time period. The predetermined time period can be referred to as a channel occupancy time (COT). On the other hand, when the channel is in the busy state, the transmitting node can continue to perform the CCA operation. The transmitting node can measure a strength of a received signal in a channel sensing period, and can determine an occupancy state of the channel by comparing the measured strength of the received signal with a threshold value. For example, the threshold value can be an energy detection threshold value. The threshold value can be predefined in a technical specification. Alternatively, the threshold value can be configured from a base station to a terminal. The above-described operation can be referred to as an LBT operation.

[0101] The LBT operation can be performed in various schemes according to the presence and absence of the CCA and a scheme of the CCA. For example, a communication node can transmit a signal without performing the CCA. This operation can be referred to as a first type LBT. For another example, a communication node can perform the CCA in a sensing period having a predefined length, and can transmit a signal after the sensing period according to a result of performing the CCA. Specifically, the communication node can sense a channel in at least a part (e.g., at least one sensing slot) of the sensing period, and when a time during which a signal having a strength equal to or less than a threshold value is received is equal to or greater than a reference time (e.g., 4 μs), the communication node can determine that the channel is in an idle state. For example, a length of the sensing period can be 25 μs, 16 μs, 9 μs, etc. The above-described operation can be referred to as a second type LBT. Further, since the above-described operation includes one CCA, it can be referred to as "one LBT".

[0102] In addition, a length of the sensing period can be variable. A communication node can perform the CCA in an initial sensing period, and when the channel is in the idle state, the communication node can transmit a signal after the sensing period. On the other hand, when the channel is in the busy state, the communication node can extend the sensing period and perform an additional sensing operation in the extended sensing period. The sensing period can be extended by a random backoff scheme, and a length of the extended sensing period can be proportional to a random backoff value. The random backoff value can be determined within a contention window (CW). For example, when the random backoff value and a size of the contention window are N init and CW p , respectively, N init may be selected as an arbitrary value between 0 and CW P . N init and CW p may each be an integer.

[0103] For example, the communication node can additionally perform CCA in an extended N init CCA in a continuous defer period, and can transmit a signal after the sensing period when the channel is in an idle state in all sensing slots (e.g., the entire sensing period). Also, the communication node can perform a defer operation when a completion time of the sensing operation (e.g., a time at which a backoff counter value becomes 0) and a time at which the signal will be transmitted do not match, perform an additional sensing operation before transmitting the signal, and can transmit the signal according to a result of the additional sensing operation. In the above-described LBT operation, the initial sensing operation can be omitted. The above-described operation can be referred to as a third-type LBT or a fourth-type LBT. In the case of the third-type LBT, the size of the contention window can be fixed. In the case of the fourth-type LBT, the size of the contention window can be adjusted according to a predetermined procedure. For example, the size of the contention window can be changed according to the type of the signal to be transmitted, a category of channel access priority class (CAPC), a frequency regulation, whether a previous transmission was successful (e.g., HARQ-ACK reception), etc.

[0104] In the NR communication system or the LTE communication system, the above-described LBT operation scheme can be applied to a channel access procedure for a payload-based equipment (LBE). For example, the first-type LBT can be applied to a type 2C channel access procedure. The second-type LBT can be applied to a type 2A and a type 2B channel access procedure. The fourth-type LBT can be applied to a type 1 channel access procedure. Also, the above-described LBT operation scheme can be applied to a channel access procedure for a frame-based equipment (FBE). The LBE and FBE operation schemes will be described later.

[0105] The expression "a communication node initiates or secures a COT or channel occupancy (CO)" can mean "the communication node occupies a channel(s) by success of an LBT operation". The expression "a communication node transmits a signal in a COT or CO" can mean "the communication node transmits a signal on an occupied channel(s) for a predetermined period". Here, the CO can mean an occupied channel(s) by a communication node or a transmission(s) on an occupied channel(s) by a communication node. Alternatively, the CO can mean a set of an occupied channel(s) by a communication node and a period occupied by the communication node. In an exemplary embodiment, the CO and the COT can be used with the same meaning. In an exemplary embodiment, a node that initiates or starts a COT (e.g., an initiating node) can be referred to as a "transmitting node", and a node that transmits and receives a signal in a COT without initiating or starting the COT can be referred to as a "receiving node". The COT can be shared from the transmitting node to the receiving node. The receiving node can perform a transmission operation as well as a reception operation in the shared COT. Accordingly, the transmitting node can perform not only a transmission operation but also a reception operation in the shared COT.

[0106] Figure 3a is a conceptual diagram illustrating a first exemplary embodiment of a communication method within a COT, and Figure 3b is a conceptual diagram illustrating a second exemplary embodiment of a communication method within a COT.

[0107] Referring to Figure 3a , a base station (e.g., gNB) can initiate a COT by performing an LBT operation. The base station can transmit a downlink transmission burst (i.e., Tx burst) at a beginning portion of the COT. Further, the COT initiated by the base station can be shared with a terminal. The terminal can transmit an uplink transmission burst within the shared COT. In this case, the terminal can perform an LBT operation to transmit the uplink transmission burst. For example, the terminal can perform a CCA before the uplink transmission burst. Alternatively, the terminal can transmit the uplink transmission burst without performing the CCA. The terminal can obtain information required for the LBT operation (e.g., whether to perform the CCA, an LBT category, a length of a sensing period, etc.) through a pre-defined rule and / or a signaling procedure from the base station. The CCA operation of the terminal can be performed within a period T1. T1 can be a time interval between an end time of a previous transmission burst (e.g., downlink transmission burst) and a start time of the uplink transmission burst.

[0108] The downlink transmission burst can be a set of consecutive downlink signals and / or channels in a time domain. The uplink transmission burst can be a set of consecutive uplink signals and / or channels in a time domain. The expression that "signals and / or channels constituting a transmission burst (e.g., downlink transmission burst and / or uplink transmission burst) are consecutive in a time domain" means that "a gap between signal transmission and / or channel transmission is equal to or less than a reference value". The reference value can be pre-defined in a technical specification. For example, the reference value can be 0. For another example, the reference value can be a value (e.g., 16 µs) greater than 0.

[0109] Referring to Figure 3b , a terminal can acquire a COT by performing an LBT operation. The terminal can transmit an uplink transmission burst at a beginning portion of the COT. Further, the COT initiated by the terminal can be shared with a base station. The base station can transmit a downlink transmission burst within the shared COT. In this case, the base station can perform an LBT operation to transmit the downlink transmission burst. For example, the base station can perform a CCA before the downlink transmission burst. Alternatively, the base station can transmit the downlink transmission burst without performing the CCA. The CCA operation of the base station can be performed within a period T2. The base station can obtain information required for the LBT operation (e.g., whether to perform the CCA, an LBT category, a length of a sensing period, etc.) through a pre-defined rule. T2 can be a time interval between an end time of a previous transmission burst (e.g., uplink transmission burst) and a start time of the downlink transmission burst.

[0110] The maximum occupation time (or the maximum transmission possible time of a signal) of a channel according to a CCA operation can be defined as a maximum COT (MCOT). In an exemplary embodiment, the maximum occupation time of a channel according to a CCA operation performed by a base station can be referred to as a “downlink MCOT”, and the maximum occupation time of a channel according to a CCA operation performed by a terminal can be referred to as an “uplink MCOT”. Thus, a COT initiated by a base station can not exceed the downlink MCOT, and a COT initiated by a terminal can not exceed the uplink MCOT. The downlink MCOT and the uplink MCOT can be predefined in a technical specification according to a frequency regulation, a channel access priority, etc. A terminal can receive configuration information of the uplink MCOT from a base station. Alternatively, the downlink MCOT and the uplink MCOT can be determined through configuration information from a base station. For example, the configuration information can include information on a fixed frame period (FFP), which will be described later.

[0111] A transmitting node (or a receiving node) can inform a receiving node (or a transmitting node) of information (e.g., COT configuration information) on a COT acquired by itself through a signaling procedure (e.g., DCI signaling, uplink control information (UCI) signaling, medium access control (MAC) control element (CE) signaling, RRC signaling, etc.). The COT configuration information (or COT indication information) can include a start time of a COT, an end time of a COT, and / or a duration (e.g., a length) of a COT. The COT configuration information informed to a receiving node (or a transmitting node) by a transmitting node (or a receiving node) can be different from information on a COT actually acquired by the transmitting node. The COT configuration information can be dynamically or semi-statically configured (or indicated). Alternatively, the COT configuration information can be predefined, and the predefined configuration information can be shared in advance between communication nodes.

[0112] For example, the base station can inform the terminal of configuration information of a COT initiated by the base station. In this case, a specific operation of the terminal can depend on the COT configuration information obtained from the base station. For example, when receiving the COT configuration information from the base station, the terminal can change an LBT operation for uplink transmission (e.g., from a fourth type LBT to a second type LBT) within the COT indicated by the configuration information and perform the changed LBT operation. For another example, a PDCCH monitoring operation of the terminal within the COT indicated by the base station can be different from a PDCCH monitoring operation outside the COT indicated by the base station. For another example, a CSI-RS reception and measurement operation of the terminal within the COT indicated by the base station can be different from a CSI-RS reception and measurement operation outside the COT indicated by the base station. Conversely, the terminal can inform the base station of configuration information of a COT initiated by the terminal. In this case, a specific operation of the base station can depend on the COT configuration information received from the terminal. For example, a transmission operation of the base station within a COT shared with the terminal can be determined based on the configuration information of the shared COT.

[0113] In addition, a communication device (e.g., a communication node, a base station, and a terminal) performing an LBT operation in an unlicensed band can be classified as LBE and FBE. Furthermore, a channel access procedure of an unlicensed band can be performed based on an LBE operation scheme and / or an FBE operation scheme. When using the LBE operation scheme, a communication node can perform a sensing operation for channel access at a time desired by the communication node. That is, the sensing operation can be performed in an on-demand manner. For example, the communication node can dynamically perform a channel access operation according to traffic generation. On the other hand, when using the FBE operation scheme, the communication node can perform a sensing operation for channel access at a periodically repeated time. For example, an FFP can be periodically repeated, and the sensing operation can be performed in a specific period (e.g., an idle period within the FFP) of each FFP.

[0114] Figure 4 is a conceptual diagram illustrating a first exemplary embodiment of an FFP configuration method.

[0115] Referring to Figure 4 , the FFP can include a COT and an idle period. A duration of the FFP can be referred to as T x , the COT (or CO) having a length T y may be arranged at a front portion of the FFP, and the idle period having a length T z may be arranged at a rear portion of the FFP. Each of T x , T y , and T z may be a positive number. The sum of T y and T z may be T xHere, COT can denote MCOT. That is, the duration of MCOT can be T y , and the COT actually occupied by the communication node can be shorter than T y . The length of the idle period can occupy Z% of the FFP. For example, Z = 5. A minimum value of the length of the idle period can be defined. For example, the minimum value of the length of the idle period can be 100 µs. In this case, T z may be max(0.05 × T x , 100 µs). The FFP can occur periodically and repeatedly, and (20 / T x ) FFPs can be arranged within two consecutive radio frames (e.g., a 20 ms period).

[0116] The communication node (e.g., base station) can determine the FFP. In addition, the communication node (e.g., base station) can change the FFP. The determined FFP or the changed FFP can last for at least a certain period. That is, a minimum change period of the FFP can be defined. In addition, the communication node (e.g., base station) can transmit the FFP or configuration information about the FFP to another communication node (e.g., terminal), and the other communication node (e.g., terminal) can determine the FFP based on the FFP and the configuration information about the FFP, and perform a transmission operation and / or a channel access operation in the channel with the communication node (e.g., base station) within the determined FFP.

[0117] When the sensing operation is successful in the idle period before the FFP (e.g., when the channel is determined to be in an idle state), the communication node can transmit a signal within the COT of the corresponding FFP. On the other hand, if the sensing operation fails in the idle period before the FFP (e.g., when the channel is determined to be in a busy state), the communication node can not perform a channel occupancy operation and / or a signal transmission operation within the COT of the corresponding FFP. In this case, the communication node can attempt CCA in the idle period of the FFP for the next FFP.

[0118] The LBT operation performed by the FBE in the idle period or the gap period (e.g., the gap period within the COT) can be a "second type of LBT operation" or an "operation similar to the second type of LBT operation (e.g., one-shot LBT)". For example, the FBE can perform an energy detection operation during a slot duration of at least Tμs within the idle period or the gap period, and can determine a channel state based on a comparison result between a result of the energy detection operation and an energy detection threshold. T can be predefined in a technical specification. For example, T can be 9. The FBE operation scheme can be used when an environment in which other communication systems do not coexist is guaranteed (from a frequency regulation perspective). For example, in an NR or LTE communication system, the FBE operation scheme can be used in an environment in which a WiFi system and a WiFi device do not coexist. In addition, when a certain condition is satisfied, a communication node (e.g., a base station or a terminal) can transmit a signal (e.g., a downlink transmission burst, an uplink transmission burst) within the COT without performing a channel sensing operation. For example, when a gap between a signal to be transmitted by the communication node and a previous transmission is less than or equal to a reference value, the communication node can transmit the signal without performing the channel sensing operation. That is, the channel sensing operation can be skipped.

[0119] In an exemplary embodiment, the idle period can represent a period defined in absolute time (e.g., a period of Tμs). Alternatively, the idle period can represent a set of symbols. For example, the idle period can be a set of symbols overlapping with the idle period defined in absolute time. Specifically, the operation of the communication node (e.g., a base station, a terminal) related to the idle period can be based on the latter meaning. z

[0120] In the FBE operation scheme, the COT can be initiated by the base station. When the LBT operation is successful in the idle period, the base station can transmit a downlink transmission burst to the terminal from the start time of the COT. In addition, the base station can transmit the downlink transmission burst at different times within the COT. That is, the base station and the terminal can perform discontinuous downlink transmissions within one COT. The COT initiated by the base station can be shared with the terminal. In this case, the terminal can transmit an uplink transmission burst to the base station within the shared COT.

[0121] ​The base station can transmit configuration information for LBT operation to the terminal. The configuration information for LBT operation can be transmitted through higher layer signaling (e.g., RRC signaling, SIB, SIB1). The configuration information for LBT operation can include information indicating an LBT operation scheme (e.g., LBE operation scheme or FBE operation scheme) to be performed by the terminal. The terminal can receive the configuration information for LBT operation from the base station. When the FBE operation scheme is used, the configuration information for LBT operation can further include information on FFP (e.g., period or length of FFP). In addition, the configuration information for LBT operation can include arrangement positions of each FFP in the time domain, arrangement positions of COT constituting each FFP, and / or arrangement positions of idle periods constituting each FFP. Alternatively, the terminal can determine the positions of each FFP in the time domain, the positions of COT constituting each FFP, and / or the positions of idle periods constituting each FFP in the time domain according to the configuration information on LBT operation (e.g., information on FFP) and a pre-defined rule.

[0122] The exemplary embodiments can be applied to both the LBE operation scheme and the FBE operation scheme. Alternatively, the exemplary embodiments can be applied to any one of the LBE operation scheme and the FBE operation scheme. In the exemplary embodiments, "COT or CO" can refer to "LBE operation-based COT or CO". In addition, in the exemplary embodiments, "COT or CO" can refer to "FBE operation-based COT or CO".

[0123] In addition, the LBT operation can be performed on a bundle of specific frequencies basis. The bundle of frequencies can be referred to as "channel", "LBT subband", "subband", or "resource block (RB) set". In the exemplary embodiments, the LBT subband or subband can mean the RB set. In the exemplary embodiments, the channel can mean the LBT subband, subband, RB set, etc. Alternatively, the channel can correspond to the LBT subband, subband, RB set, etc. The LBT operation can include the above-described CCA operation. Alternatively, the LBT operation can include "CCA operation + signal and / or channel transmission operation according to the CCA operation". The bandwidth of the channel or LBT subband can vary according to the spectrum regulation, frequency band, communication system, operator, and manufacturer. For example, the bandwidth of the channel in the 5 GHz band can be 20 MHz. The communication node can perform sensing and data transmission in a 20 MHz or a bundle of frequencies corresponding to 20 MHz unit.

[0124] An LBT subband can be a set of contiguous RBs. A size of an LBT subband can correspond to a bandwidth of a channel (e.g., 20 MHz). A base station can configure an LBT subband to a terminal. Configuration information of an LBT subband can include information on a set of RBs constituting the LBT subband (e.g., a start RB, an end RB, and / or a number of RBs). One carrier and / or one bandwidth part can include at least one LBT subband. When a carrier is composed of a plurality of LBT subbands, configuration information of each LBT subband can be signaled to a terminal.

[0125] When a carrier and / or a bandwidth part is composed of a plurality of LBT subbands, a guard band can be inserted between adjacent LBT subbands. A guard band can be disposed within a carrier. To distinguish between a guard band within a carrier and a guard band outside a carrier, a guard band within a carrier can be referred to as an "intra-carrier guard band" or an "intra-cell guard band". In an exemplary embodiment, for convenience, an intra-carrier guard band or an intra-cell guard band can be collectively referred to as a "guard band". A guard band can be a set of contiguous RBs. An RB constituting a guard band can be referred to as a guard RB. If the number of LBT subbands constituting a carrier is L, (L-1) guard bands can be disposed in a carrier. L can be a natural number. A size of a guard band can be zero.

[0126] Figure 5 is a conceptual diagram illustrating a first exemplary embodiment of a method for configuring LBT subbands and guard bands.

[0127] Referring to Figure 5 , one carrier can be composed of four LBT subbands. Three guard bands can be disposed between adjacent LBT subbands. In this case, L (i.e., the number of LBT subbands) can be 4. LBT subbands and guard bands can be configured based on a carrier. Each LBT subband and each guard band can be composed of some of contiguous CRBs constituting a carrier.

[0128] The base station can inform the terminal of information about a frequency range (e.g., a start CRB index, an end CRB index, and / or a number of CRBs (or a number of RBs)) of each LBT sub-band and / or a number of LBT sub-bands constituting a carrier through a signaling procedure (e.g., an RRC signaling procedure). The base station can inform the terminal of information about a frequency range (e.g., a start CRB index, an end CRB index, and / or a number of CRBs (or a number of RBs)) of each guard frequency segment and / or a number of guard frequency segments constituting a carrier through a signaling procedure (e.g., an RRC signaling procedure). The LBT sub-band and the guard frequency segment configured for a carrier can be equally applied to a bandwidth part belonging to the corresponding carrier. That is, the terminal can consider a PRB corresponding to a CRB constituting each LBT sub-band and each guard frequency segment in a bandwidth part as an LBT sub-band and a guard frequency segment for the bandwidth part. Each LBT sub-band can be completely included in the bandwidth part. Alternatively, each LBT sub-band can not be completely included in the bandwidth part. That is, each LBT sub-band can not be partially included in the bandwidth part. Alternatively, the bandwidth part can include a part of the LBT sub-band. For example, an initial downlink bandwidth part can occupy a part of a frequency region of the LBT sub-band.

[0129] A union of RBs constituting the LBT sub-band and the guard frequency segment can be the same as a set of RBs constituting the carrier (or the bandwidth part). That is, each RB constituting the carrier (or the bandwidth part) can belong to at least one LBT sub-band or guard frequency segment. Additionally or alternatively, a set of RBs constituting each LBT sub-band and a set of RBs constituting each guard frequency segment can be disjoint sets. That is, each RB constituting the carrier (or the bandwidth part) can belong to only one LBT sub-band or only one guard frequency segment. In this case, the terminal can acquire a frequency range of the LBT sub-band based on configuration information about the guard frequency segment received from the base station. For example, a start RB of a first sub-band can be a start RB of the carrier, and an end RB of the first sub-band can be an RB before a start RB of a first guard frequency segment. For another example, a start RB of a last sub-band can be an RB after a last RB of a last guard frequency segment, and an end RB of the last sub-band can be an end RB of the carrier.

[0130] The guard frequency segment can be independently configured for each of the downlink and the uplink. Accordingly, the LBT sub-band can also be independently configured for each of the downlink and the uplink. A frequency range (e.g., a start CRB index, an end CRB index, and / or a number of CRBs (or a number of RBs)) of the guard frequency segment can be pre-defined in a technical specification. When information about the frequency range of the guard frequency segment is not received from the base station, the terminal can determine the frequency range of the LBT sub-band and the guard frequency segment based on the frequency range of the guard frequency segment defined in the technical specification.

[0131] A communication node (e.g., base station, terminal) can perform an LBT operation and can occupy an LBT sub-band in which a CCA (e.g., LBT operation) is successful. That is, the communication node can initiate a COT in an LBT sub-band in which a CCA is successful. The communication node can transmit a signal in the occupied LBT sub-band during a COT period. The base station can indicate information about a valid LBT sub-band and / or an invalid LBT sub-band to the terminal. The above information can be transmitted to the terminal together with configuration information of the COT. Alternatively, the above information can be included in the configuration information of the COT transmitted to the terminal. The base station can determine at least some of the LBT sub-bands occupied by the base station as a valid LBT sub-band. The communication node can not transmit a signal in a guard band. Alternatively, the communication node can transmit a signal in the guard band. For example, when transmission is performed in the guard band and two adjacent LBT sub-bands, the transmission in the guard band can be performed at least simultaneously with the transmission in the two LBT sub-bands.

[0132] In addition, an uplink data channel (e.g., PUSCH) can be scheduled through a dynamic grant or a configured grant. The dynamic grant can be a DCI (or DCI format) including scheduling information, and the base station can transmit the DCI (or DCI format) to the terminal through a downlink control channel (e.g., PDCCH). The configured grant can include information for semi-static or semi-persistent configuration, dynamic reconfiguration of scheduling, etc., for scheduling, and the base station can transmit the configured grant to the terminal through higher layer signaling (e.g., RRC signaling) and / or physical layer dynamic signaling (e.g., DCI or DCI format).

[0133] By receiving the configured grant, the terminal can obtain information about a resource region (hereinafter, referred to as "configured grant resource") in which the PUSCH can be transmitted. The configured grant resource can be periodically configured. One or more configured grant resources can be periodically repeated. When uplink traffic (e.g., uplink shared channel (UL-SCH)) is generated, the terminal can transmit the PUSCH in the configured grant resource without transmitting an additional scheduling request (SR) or receiving a dynamic grant. The PUSCH transmitted in the configured grant resource can be referred to as a "configured grant PUSCH".

[0134] [Acquisition of shared COT]

[0135] When the FBE operation scheme is used, a COT initiated by a transmitting node can be shared with a receiving node. The receiving node can transmit a signal in the shared COT. That is, the receiving node can acquire the shared COT and transmit a signal in the acquired shared COT. The receiving node can acquire the shared COT when a certain condition is satisfied. For example, when the receiving node successfully receives or detects a signal from the transmitting node that initiated the COT in the COT, the receiving node can acquire the shared COT. In this case, the signal transmitted for the purpose of sharing the COT can be referred to as a "COT acquisition signal" or a "shared COT acquisition signal". When the transmitting node and the receiving node are a base station and a terminal, respectively, if the terminal successfully receives or detects a downlink signal in a COT initiated by the base station, the corresponding COT can be considered a shared COT, and the terminal can transmit an uplink signal in the shared COT. For example, the terminal can transmit a PUSCH in the shared COT.

[0136] Figure 6a is a conceptual diagram illustrating a first exemplary embodiment of a method for transmitting a PUSCH in a shared COT, Figure 6b is a conceptual diagram illustrating a second exemplary embodiment of a method for transmitting a PUSCH in a shared COT, Figure 6c is a conceptual diagram illustrating a third exemplary embodiment of a method for transmitting a PUSCH in a shared COT, and Figure 6d is a conceptual diagram illustrating a fourth exemplary embodiment of a method for transmitting a PUSCH in a shared COT.

[0137] Referring to Figures 6a to 6d , a base station can acquire a COT by performing an LBT operation on a channel. A terminal can attempt to share a COT initiated by the base station in the channel and transmit a PUSCH within the corresponding COT.

[0138] In the exemplary embodiments shown in Figure 6a , the terminal can receive an uplink grant (e.g., an uplink DCI, an uplink DCI format, a DCI format including scheduling information of the PUSCH) corresponding to the PUSCH in the COT in which the PUSCH is to be transmitted. For example, the uplink grant can be transmitted on a PDCCH. In this case, the uplink grant (or the PDCCH including the uplink grant) can be considered a COT acquisition signal. That is, the terminal can determine to share the COT initiated by the base station by receiving the uplink grant and transmit the PUSCH within the corresponding COT.

[0139] In the exemplary embodiments shown in Figure 6bIn the exemplary embodiments shown in FIG. 1, the terminal can receive the uplink grant corresponding to the PUSCH in a region outside the COT in which the PUSCH is to be transmitted. For example, the PUSCH can be transmitted in a first COT initiated by the base station, and the uplink grant corresponding to the PUSCH can be transmitted in a second COT initiated by the base station or a COT initiated by the terminal. In this case, it can be difficult to regard the uplink grant as a COT acquisition signal for the first COT. The second COT or the COT initiated by the terminal can be located before the first COT.

[0140] In Figure 6c the exemplary embodiments shown in FIG. 1, the terminal can expect to transmit the configured grant PUSCH within the COT. The configured grant PUSCH can be semi-statically scheduled, and there can be no uplink grant corresponding to the configured grant PUSCH. That is, there can be no uplink grant as a COT acquisition signal for the corresponding COT. In Figure 6d the exemplary embodiments shown in FIG. 1, the terminal can receive the uplink grant corresponding to the PUSCH in another channel (e.g., another LBT subband, another RB set, another carrier) different from the COT (or occupied channel) in which the PUSCH is to be transmitted. The reception time of the uplink grant can belong to the period of the corresponding COT. Alternatively, the reception time of the uplink grant can not belong to the period of the corresponding COT. In this case, the uplink grant can be difficult to be regarded as a COT acquisition signal for the corresponding COT.

[0141] Figures 6b to 6d The exemplary embodiments shown in FIG. 1 can be identically applied not only to the transmission of the PUSCH but also to other uplink transmissions (e.g., PUCCH, SRS, PRACH, etc.). For example, in Figure 6b and Figure 6d the exemplary embodiments shown in FIG. 1, the PUSCH can correspond to other uplink transmissions, and the uplink grant can correspond to DCI triggering the other uplink transmissions. For another example, in Figure 6c the exemplary embodiments shown in FIG. 1, the PUSCH can correspond to other uplink transmissions (e.g., semi-statically configured PUCCH, periodic or semi-persistent SRS, PRACH, etc.). In this case, the DCI can be difficult to be regarded as a COT acquisition signal for the corresponding COT.

[0142] In Figures 6b to 6dIn the exemplary embodiments illustrated in FIGS. 1 to 3, a terminal can consider a COT in which a PUSCH is to be transmitted as a shared COT, and can have to transmit another downlink signal in addition to an uplink grant corresponding to the PUSCH within the corresponding COT in order to transmit the PUSCH. The other downlink signal can be referred to as a COT acquisition signal (or a shared COT acquisition signal). The COT acquisition signal can be transmitted earlier than the PUSCH.

[0143] Summarizing the above exemplary embodiments, a terminal can consider a corresponding COT as a shared COT when a COT acquisition signal is successfully received or detected within the COT. Also, the terminal can transmit an uplink signal in the shared COT. Within the corresponding COT, the COT acquisition signal and the uplink signal can be transmitted on the same channel. Within the corresponding COT, the COT acquisition signal can be transmitted earlier than the uplink signal.

[0144] The COT acquisition signal can be a common signal or a group common signal commonly transmitted to at least one terminal. For example, a PDCCH, a group common PDCCH, and / or a PDSCH can be used as the COT acquisition signal. The PDCCH can include a PDCCH transmitted through a CSS set and / or a PDCCH including common information (e.g., system information, a paging message, Msg2, etc.). The group common PDCCH can include a PDCCH including group common information (e.g., an SFI, a preemption indicator, power control information, an SRS request, etc.). For another example, at least some signals constituting an SS / PBCH block, a demodulation reference signal (DM-RS), a CSI-RS, a positioning reference signal (PRS), and / or a phase tracking reference signal (PT-RS) can be used as the COT acquisition signal. Information (e.g., a sequence, an identifier (ID) for signal generation, a cell ID, etc.) required to receive the above signals can be transmitted to at least one terminal, and the at least one terminal can commonly receive the above signals based on the information.

[0145] Alternatively, the COT acquisition signal can be a terminal-specific signal. For example, a PDSCH and / or a PDCCH including terminal-specific information (e.g., a PDCCH transmitted through a USS set, a PDCCH including scheduling information of a data channel, a DCI format 0_X (X=0, 1, 2,...), a DCI format 1_Y (Y=0, 1, 2,...), etc.) can be used as the COT acquisition signal. For another example, a DM-RS, a CSI-RS, a PRS, and / or a PT-RS receivable by a specific terminal can be used as the COT acquisition signal.

[0146] Additionally or alternatively, a downlink signal (e.g., DCI, DCI format, PDCCH, dynamic grant, uplink grant, CSI request, SRS request, etc.) indicating an uplink transmission can be used as a COT acquisition signal. For example, a downlink grant (e.g., DCI format 1_Y (Y = 0, 1, 2,...)), an uplink grant (e.g., DCI format 0_X (X = 0, 1, 2,...)), and / or an SRS transmission indicator (e.g., DCI format 2_3) can be used as a COT acquisition signal.

[0147] Multiple signals can be used as a COT acquisition signal. For example, at least one of the above-mentioned signals can be used as a COT acquisition signal.

[0148] When a PDCCH and / or a PDSCH is used as a COT acquisition signal, a terminal can determine whether the COT acquisition signal is successfully received by a cyclic redundancy check (CRC). Thus, the reliability of the determination of the terminal can be increased. When a synchronization signal and / or a reference signal is used as a COT acquisition signal, a terminal can use an energy detection reference value to determine whether the signal is successfully detected. In this case, the time for receiving or detecting the COT acquisition signal can be shortened.

[0149] A COT acquisition signal can be transmitted at any time (e.g., any symbol) within a COT. Alternatively, a COT acquisition signal can be transmitted in a partial period (hereinafter referred to as a "first period") of a COT. That is, a receiving node (e.g., a terminal) can receive or monitor a COT acquisition signal within the first period, and can expect not to receive a COT acquisition signal in the remaining period other than the first period. The first period can consist of some symbols within a COT. The symbols constituting the first period can be consecutive in the time domain. The first period can be predefined in a technical specification. Alternatively, a terminal can receive configuration information of the first period (e.g., a set of symbols constituting the first period, a start time of the first period, and / or a length of the first period) from a base station.

[0150] The transmitting node (e.g., base station) can transmit a signal in the idle period after the channel sensing operation is successful. Thus, the COT acquisition signal can be transmitted in a portion of the beginning of the COT. For example, the COT acquisition signal can be transmitted in a symbol including the first symbol of the COT (e.g., the first symbol of the FFP). That is, the first period can include at least the first symbol of the COT (e.g., the first symbol of the FFP). The terminal can receive or monitor the COT acquisition signal in a symbol including the first symbol of the COT. The terminal can receive suitable configuration information from the base station in order to receive the COT acquisition signal in a symbol including the first symbol of the COT. For example, when the DCI format 2_0 is used as the COT acquisition signal, the terminal can expect to receive configuration information for monitoring a search space set (e.g., a type 3 CSS set) for the DCI format 2_0 in a symbol including the first symbol of the COT. For another example, when the reference signal (e.g., periodic reference signal, semi-persistent reference signal) is used as the COT acquisition signal, the terminal can expect that the transmission resource of the reference signal includes the first symbol of the COT.

[0151] When the COT acquisition signal is not received in the first period, the terminal can consider that the corresponding COT (e.g., the COT initiated by the base station) is not occupied by the base station. For example, when the COT acquisition signal is not received in a resource (e.g., CSI-RS resource, SS / PBCH block resource, CORESET, search space set, and / or PDCCH monitoring occasion) including the first symbol of the COT initiated by the base station, the terminal can consider that the corresponding COT is not occupied by the base station. In this case, the terminal can not perform a reception operation or a monitoring operation of the COT acquisition signal within the corresponding COT. The terminal can not perform a downlink reception and / or measurement operation within the corresponding COT. If the terminal receives a downlink transmission burst, but the received downlink transmission burst does not belong to the first period of the COT (e.g., when the resource in which the downlink transmission burst is received does not include the first symbol of the COT initiated by the base station), the terminal can consider that the received downlink transmission burst is transmitted through a COT (e.g., a COT initiated by the terminal or another terminal) other than the COT initiated by the base station. The terminal can not perform an uplink transmission operation using the corresponding COT (e.g., the COT initiated by the base station). According to the above-described method, the power consumption of the terminal can be reduced.

[0152] In addition, after successfully receiving the COT acquisition signal, the terminal can transmit an uplink signal within the corresponding COT. The time required to determine whether the COT acquisition signal is successfully received can vary for each terminal. In addition, when multiple COT acquisition signals are used, the time required to determine whether the COT acquisition signal is successfully received can be different for each type of COT acquisition signal. In this case, since the base station does not accurately identify the time for the terminal to process (e.g., receive and / or detect) the received COT acquisition signal, the time for the terminal to determine whether the COT is acquired, and / or the time for the terminal to prepare to transmit the uplink signal, it can be difficult for the base station to determine from what point in time the terminal can perform uplink transmission. That is, uncertainty can occur in the uplink transmission.

[0153] As a method for solving the above problem, the processing time (or reference value) required for the terminal to acquire the shared COT can be predefined (e.g., in a technical specification). The processing time (or reference value) can be referred to as a "COT acquisition processing time," a "shared COT acquisition processing time," a "processing time for verification of COT sharing," a "processing time for verification of uplink transmission," etc. The processing time (or reference value) can be expressed as T proc,cot .

[0154] Specifically, T proc,cot may include the time required for the terminal to process (e.g., receive and / or detect) the received COT acquisition signal, the time for the terminal to determine whether the COT is acquired, and / or the time for the terminal to prepare to transmit the uplink signal. When the COT acquisition signal is received within the COT, the terminal can determine the validity of the uplink transmission within the corresponding COT based on a relationship between the reception time of the COT acquisition signal (e.g., the symbol to which the COT acquisition signal is mapped), the transmission time of the uplink signal (e.g., the symbol to which the uplink signal to be transmitted by the terminal is mapped), and T proc,cot .

[0155] For example, when the COT acquisition signal is received within the COT, if the first symbol of the uplink transmission is not within the time T proc,cotAfter the earliest symbol before which the terminal can consider the uplink transmission to be valid and can transmit the corresponding uplink signal. On the other hand, when the uplink transmission does not satisfy the above condition, the terminal can consider the uplink transmission to be invalid and can not transmit the corresponding uplink signal. Here, the duration of a symbol can be a period including a CP period. That is, the start time of a symbol can represent the start time of a CP period. In consideration of the above operation of the terminal, the base station can configure (or indicate) the uplink transmission or can transmit the COT acquisition signal. The above method can be referred to as (Method 100). (Method 100) can be applied to FBE or FBE operation scheme. In addition, (Method 100) can be applied to LBE or LBE operation scheme.

[0156] T proc,cot may be determined according to the subcarrier spacing of the COT acquisition signal, the subcarrier spacing of the uplink signal, and / or the processing capability of the terminal. proc,cot A plurality of T proc,cot may be defined, and each T proc,cot may be defined as a processing capability of the terminal. For example, T proc,cot1 and T proc,cot2 may be defined. Alternatively, a parameter (e.g., delay time in units of symbols) indicating a capability related to the terminal processing time can be defined, and T proc,cot may be defined as a function of the above parameter. The terminal can support at least one of a plurality of capabilities related to T proc,cot . The terminal can transmit its own capability for T proc,cot to the base station. The base station can perform the uplink transmission and / or the COT acquisition signal transmission based on the capability information received from the terminal in consideration of (Method 100).

[0157] For example, 'T proc，cot = A × (2048 + 144) × κ × 2 -μ × T c ' can be defined. Here, A can be a delay time in units of symbols (e.g., the number of symbols). κ can be 64. T c may be 1 / (480×103×4096). μ can be the subcarrier spacing of the COT acquisition signal and the subcarrier spacing of the uplink signal, among which the subcarrier spacing providing a larger T proc,cot may be defined. A plurality of candidate values for A can be defined. Whether the terminal supports a specific candidate value for A can be defined as a capability of the terminal. For another example, 'T proc，cot = max(A × (2048 + 144) × κ × 2 -μ × T c , C)' can be defined. Here, C can represent a switching time of a bandwidth part. For another example, 'T proc，cot= max((A + B) x (2048 + 144) x K x 2 -μ x T c , C). Here, B can denote an additional delay time in a symbol unit (e.g., the number of additional symbols). For example, when a first symbol of an uplink signal (e.g., PUSCH) includes only DM-RS, B can be 0. When a first symbol of an uplink signal (e.g., PUSCH) includes not only DM-RS, B can be 1.

[0158] The (method 100) can be applied to each uplink transmission. That is, the terminal can determine validity of each uplink transmission (e.g., determine whether to perform each uplink transmission) based on the (method 100). The uplink transmission can include transmission of PUSCH, PUCCH, DM-RS, SRS, and / or PRACH. The unit of the uplink transmission to which the (method 100) is applied can be a "resource". For example, the terminal can determine validity in a unit of a time resource (e.g., duration, symbol) to which each PUSCH, PUCCH, DM-RS, SRS, and / or PRACH is mapped. When a repetition transmission is applied to the uplink transmission, the unit of the uplink transmission to which the (method 100) is applied can be "each transmission instance" of the repetition transmission. For example, when the terminal is scheduled to transmit PUSCH for the same transport block (i.e., TB) repeatedly, the terminal can determine validity for each PUSCH instance, and transmit only the valid PUSCH instance. Alternatively, the unit of the uplink transmission to which the (method 100) is applied can be a "symbol". For example, when the terminal wants to transmit SRS, the terminal can determine validity of the SRS transmission in a unit of a symbol, and can transmit the SRS in the valid symbol. That is, when one SRS resource is configured with a plurality of symbols, according to the (method 100), the SRS can be transmitted only in some symbols.

[0159] When a downlink signal (e.g., DCI, DCI format, PDCCH, dynamic grant, uplink grant, CSI request, SRS request, etc.) indicating an uplink transmission is transmitted within the same COT as the uplink transmission, the downlink signal can be used as a COT acquisition signal. In this case, the terminal can determine the validity of the uplink transmission based on the downlink signal and the T proc,cotA separately defined processing time (or reference value) is used to determine the validity of the uplink transmission. For example, when an uplink grant indicating a transmission of a PUSCH is received within the same COT as the corresponding PUSCH, the terminal can determine whether to transmit the PUSCH based on the uplink grant and the separately defined processing time (or reference value). In this case, the above-described method can be prioritized over (method 100). Alternatively, when a downlink signal indicating an uplink transmission is used as a COT acquisition signal, the terminal can determine whether to transmit the corresponding uplink signal based on (method 100).

[0160] According to (method 100), the terminal can determine whether each PUSCH is valid based on the location of the time resource of each PUSCH allocated within the COT initiated by the base station. The terminal can perform an operation of transmitting the PUSCH determined to be valid, and can expect to receive a retransmission indication for the corresponding PUSCH (or a TB corresponding to the PUSCH and / or a HARQ process) from the base station. The retransmission indication can be performed through an uplink grant or a configured grant-downlink feedback information (CG-DFI), and can be transmitted to the terminal through DCI. In addition, the terminal can not perform an operation of transmitting the PUSCH determined to be invalid, and can not expect to receive a retransmission indication for the corresponding PUSCH (or a TB corresponding to the PUSCH and / or a HARQ process). For example, when the PUSCH is an initial transmission, the terminal can not expect to receive a retransmission indication for the corresponding PUSCH from the base station. The PUSCH can be a configured grant PUSCH.

[0161] When multiple downlink signals are used as COT acquisition signals, T proc,cot may be commonly applied to a set of COT acquisition signals. The same T proc,cot may be applied to a set of COT acquisition signals. For example, the set of COT acquisition signals to which the same T proc,cot may be applied can include at least one physical channel. That is, the set of COT acquisition signals to which the same T proc,cot may be applied can include a group common PDCCH (e.g., DCI format transmitted to a group of terminals), a PDCCH, and / or a PDSCH. For another example, the set of COT acquisition signals to which the same T proc,cot may be applied can include at least one physical signal. That is, the set of COT acquisition signals to which the same T proc,cot may be applied can include at least some signals constituting an SS / PBCH block, a DM-RS, a CSI-RS, a PRS, and / or a PT-RS. In addition, when a plurality of T proc,cot is defined, each T proc,cot of the plurality of T proc,cot may be applied to a different set of COT acquisition signals.

[0162] As described above, the transmitting node can perform LBT operation on multiple channels (e.g., multiple LBT subbands, multiple RB sets), and initiate a common COT for the channels on which the transmitting node succeeds in CCA. Alternatively, the transmitting node can independently initiate a COT for each of the channels on which it succeeds in CCA. For multiple channels, the common COT or individual COTs can be shared with the receiving node, and the receiving node can perform transmission in the shared COT. In this case, when successfully receiving or detecting a COT acquisition signal, the terminal (e.g., the receiving node) can acquire the shared COT in a channel different from the channel on which the COT acquisition signal is received, and can transmit an uplink signal in the shared COT. Further, when successfully receiving or detecting a COT acquisition signal, the terminal can acquire the shared COT in multiple channels, and transmit an uplink signal in the shared COT. The multiple channels can include the channel on which the terminal receives the COT acquisition signal. Further, the multiple channels can include a channel different from the channel on which the terminal receives the COT acquisition signal. The above-described method can be referred to as (Method 110).

[0163] The above-described method can be equally applied to (Method 100). That is, even when the channel on which the terminal receives the COT acquisition signal and the channel on which the uplink transmission is performed are different from each other, (Method 100) can be applied. Further, the terminal can check the validity of the uplink transmission for the multiple channels based on (Method 100), and can determine whether to perform the uplink transmission. The validity check of the uplink transmission can be independently performed for each of the multiple channels. The multiple channels can include the channel on which the terminal receives the COT acquisition signal. Further, the multiple channels can include a channel different from the channel on which the terminal receives the COT acquisition signal. The above-described method can be referred to as (Method 120).

[0164] The channel (e.g., LBT subband, RB set) on which the COT acquisition signal is received and the channel (e.g., LBT subband, RB set) for performing the uplink transmission can belong to the same carrier and / or the same bandwidth part. Alternatively, the channel (e.g., LBT subband, RB set) on which the COT acquisition signal is received and the channel (e.g., LBT subband, RB set) for performing the uplink transmission can belong to different carriers and / or different bandwidth parts. In this case, the above-described method (e.g., (Method 110), (Method 120)) can be applied between the different carriers and / or different bandwidth parts. For example, the terminal can receive the COT acquisition signal in a first carrier (or a first bandwidth part), and determine the uplink transmission operation in a second carrier (or a second bandwidth part) based on the COT acquisition signal.

[0165] In the case of the FBE operating scheme, the boundaries of the FFPs for the multiple channels can be aligned with each other. Alternatively, the boundaries of the FFPs for the multiple channels can not be aligned with each other. When the FFP of the channel on which the terminal receives the COT acquisition signal and the FFP of the channel on which the terminal performs the uplink transmission are aligned with each other in time, the above-described method (e.g., (method 110), (method 120)) can be used. Alternatively, when the FFP of the channel on which the terminal receives the COT acquisition signal and the FFP of the channel on which the terminal performs the uplink transmission are generally not aligned with each other, the above-described method (e.g., (method 110), (method 120)) can be used. In this case, the period of the channel on which the terminal performs the uplink transmission according to the reception of the COT acquisition signal that is shared with the terminal can be the same as the period of the COT (e.g., the COT on which the COT acquisition signal is received) of the channel on which the terminal receives the COT acquisition signal. Alternatively, the period of the channel on which the terminal performs the uplink transmission according to the reception of the COT acquisition signal that is shared with the terminal can be determined based on the period of the COT (e.g., the COT on which the COT acquisition signal is received) of the channel on which the terminal receives the COT acquisition signal.

[0166] For another example, the period of the channel on which the terminal performs the uplink transmission according to the reception of the COT acquisition signal that is shared with the terminal can be the COT of the channel on which the uplink transmission is performed. Alternatively, the period of the channel on which the terminal performs the uplink transmission according to the reception of the COT acquisition signal that is shared with the terminal can be determined based on the COT of the channel on which the uplink transmission is performed. The COT that is shared with the terminal can be determined based on the reception time of the COT acquisition signal. For example, the COT that is shared with the terminal can be the COT including the reception time (or the reception period) of the COT acquisition signal. Alternatively, the COT that is shared with the terminal can be the first COT after the reception time (or the reception period) of the COT acquisition signal. In addition, the terminal can receive the COT acquisition signal at multiple time points (e.g., multiple time points in the same or different channels). In this case, the sum of the periods shared with the terminal through the reception of the respective COT acquisition signals can be shared with the terminal, and the terminal can transmit the uplink signal in the sum of the periods of the relevant channels.

[0167] As described above, DCI format 2_0 can be used as a COT acquisition signal. DCI format 2_0 may include a COT duration indicator. The terminal may obtain the COT duration indicator from DCI format 2_0 and may identify the length of the entire period of the COT or the length of the remaining period of the COT based on the COT duration indicator. For example, the COT duration indicator may include information about the time (e.g., the number of symbols) from a reference time (e.g., a reference symbol) to the end time of the COT (e.g., the last symbol of the COT). For example, the reference time may be the start time of the COT (e.g., the first symbol constituting the COT). For another example, the reference time may be the symbol (e.g., the first symbol) of the time slot in which the DCI format 2_0 including the COT duration indicator is transmitted.

[0168] The terminal can identify the position of the end time of the COT (e.g., the last symbol of the COT) based on the above information. Alternatively, the terminal can receive information about the end time of the COT (e.g., the last symbol of the COT) directly from the base station. For example, information about the end time of the COT can be included in the DCI format 2_0 sent to the terminal. In addition, the terminal can determine which symbol(s) belong to the COT based on the above information. When a symbol in which a CSI-RS (e.g., periodic CSI-RS, semi-persistent CSI-RS) is configured belongs to the COT, the terminal can receive the CSI-RS in the corresponding symbol and perform operations related to the received CSI-RS (e.g., CSI measurement and / or calculation).

[0169] On the other hand, when the symbol for configuring CSI-RS (e.g., periodic CSI-RS, semi-permanent CSI-RS) does not belong to COT, the terminal may not perform a CSI-RS reception operation in the corresponding symbol. In addition, when the symbol for configuring uplink transmission belongs to COT, the terminal may change the LBT type used for uplink transmission. For example, the LBT type for uplink transmission may be changed from the fourth type of LBT (or type 1 channel access procedure) to the second type of LBT (or type 2 or 2A channel access procedure). Each operation in the CSI-RS reception operation and the uplink LBT operation may be determined based on whether a COT duration indicator and / or COT duration information indicated by the COT duration indicator is received. When the COT duration indicator and / or information about the end time of the COT is not included in DCI format 2_0, information about the COT duration and / or information about the end time of the COT may be obtained from the SFI of DCI format 2_0.

[0170] On the other hand, in the case of the FBE operation scheme, the start time and / or the end time of the COT can be predetermined through the above-described FFP structure. That is, the start time of the COT can be the first symbol in the FFP, and the end time of the COT can be the last symbol among the symbols in the FFP which does not overlap with the idle period. The transmitting node (e.g., base station) and the receiving node (e.g., terminal) can consider that the start time and / or the end time of the COT are the same. The terminal can ignore the information on the duration of the COT and / or the end time of the COT indicated by the COT duration indicator included in the DCI format 2_0.

[0171] Alternatively, the terminal can expect that the COT duration indicator included in the DCI format 2_0 indicates the number of symbols from the reference time (e.g., the first symbol of the slot in which the DCI format 2_0 is transmitted) to the predetermined end time of the COT (e.g., the last symbol among the symbols within the FFP which does not overlap with the idle period). That is, the terminal can expect that the last symbol of the COT obtained from the COT duration indicator coincides with the predetermined end time of the COT (e.g., the last symbol among the symbols within the FFP which does not overlap with the idle period). Alternatively, in the case of the FBE operation scheme, the DCI format 2_0 can not include the COT duration indicator.

[0172] The terminal can consider that the COT is obtained by receiving the DCI format 2_0. In addition, the information indicated by the fields of the DCI format 2_0 can not be necessary for the terminal. In this case, at least a part of the payload of the DCI format 2_0 can have a predefined size and value (i.e., dummy value). For example, at least a part of the payload of the DCI format 2_0 can include a bit string having a predefined length and value. For example, the bit string can be a bit string in which all bits have a value of "0" or a bit string in which all bits have a value of "1". The dummy value or bit string can be defined as a specific field (e.g., COT duration indicator, SFI, valid RB set indicator, search space set switching indicator, etc.). For example, the DCI format 2_0 can include only the COT duration indicator field, and the COT duration indicator field can have a predefined bit string. Alternatively, the DCI format 2_0 can include other fields in addition to the COT duration indicator field. The encoding and decoding of the DCI format 2_0 having the dummy value or bit string can be performed through the polar code. The length of the bit string can be at least 12.

[0173] [PUSCH transmission]

[0174] The PUSCH can be repeatedly transmitted. That is, the PUSCH can be repeatedly transmitted for the same TB a plurality of times.

[0175] Figure 7is a conceptual diagram illustrating an exemplary embodiment of a method for repeatedly transmitting a PUSCH in a shared COT.

[0176] Referring to Figure 7 In the first exemplary embodiment to the fourth exemplary embodiment illustrated in FIGS. 1 to 4, consecutive FFPs can exist and a free period can be provided in an end portion of each FFP. Further, a slot format of each slot can include a downlink (D) period, a flexible (F) period, and / or an uplink (U) period. A period or a symbol marked as “free” in the slot format can include a symbol overlapping with the free period. The period or the symbol marked as “free” can be configured as a downlink symbol, a flexible symbol, and / or an uplink symbol. The period or the symbol marked as “free” can be configured in a separate format (e.g., “free period” or “free symbol”) distinguished from the downlink, the flexible, and the uplink. The period or the symbol marked as “free” can be configured to a terminal through separate signaling different from slot format configuration signaling. In the period or the symbol marked as “free”, a communication node (e.g., a base station, a terminal) can not transmit a signal. The symbol marked as “free” can be referred to as a free symbol. In an exemplary embodiment, a PUSCH can be repeatedly transmitted for the same TB.

[0177] In Figure 7 In the first exemplary embodiment illustrated in FIG. 1, a terminal can receive scheduling information for four times of repeated transmission of a PUSCH. Four PUSCH instances (e.g., a first PUSCH instance to a fourth PUSCH instance) or four PUSCH resources (i.e., a first PUSCH resource to a fourth PUSCH resource) can be consecutive in time. A PUSCH instance (e.g., a second PUSCH instance) can be allocated across two slots. For example, the second PUSCH instance can include a slot boundary. A PUSCH instance (e.g., a second PUSCH instance) can include a downlink symbol (e.g., a semi-statically configured downlink symbol). A PUSCH instance (e.g., a first PUSCH instance and a second PUSCH instance) can include a free symbol. The PUSCH instance can be a nominal PUSCH instance scheduled to the terminal, and the PUSCH resource can be a nominal PUSCH resource scheduled to the terminal. The terminal can transmit the PUSCH instance in the nominal resource scheduled by the base station.

[0178] In Figure 7 In the second exemplary embodiment to the fourth exemplary embodiment illustrated in FIGS. 2 to 4, a resource in which a PUSCH instance is actually transmitted can be different from a nominal resource. A terminal can not use a nominal PUSCH resource scheduled by a base station as it is. That is, the terminal can configure a new resource by changing the nominal PUSCH resource according to a predetermined rule, and transmit a PUSCH instance in the new resource. In the second exemplary embodiment to the fourth exemplary embodiment illustrated in FIGS. 2 to 4, a PUSCH instance (e.g., a second PUSCH instance) can be allocated across two slots. For example, the second PUSCH instance can include a slot boundary. A PUSCH instance (e.g., a second PUSCH instance) can include a downlink symbol (e.g., a semi-statically configured downlink symbol). A PUSCH instance (e.g., a first PUSCH instance and a second PUSCH instance) can include a free symbol. The PUSCH instance can be a nominal PUSCH instance scheduled to the terminal, and the PUSCH resource can be a nominal PUSCH resource scheduled to the terminal. The terminal can transmit the PUSCH instance in the nominal resource scheduled by the base station. Figure 7In the second exemplary embodiment shown in FIG. 2, some PUSCH instances (e.g., the second PUSCH instance) can be segmented based on a slot boundary and / or a downlink period (e.g., semi-statically configured downlink symbols) and can be transmitted in symbols other than the downlink period (e.g., semi-statically configured downlink symbols). The terminal can transmit the PUSCH instances corresponding to some PUSCH instances (e.g., the second PUSCH instance) in the changed resources. The terminal can transmit the remaining PUSCH instances (e.g., the first PUSCH instance, the third PUSCH instance, and the fourth PUSCH instance) in the nominal resources.

[0179] In Figure 7 In the third exemplary embodiment shown in FIG. 3, the resources of some PUSCH instances (e.g., the first nominal PUSCH instance and the second nominal PUSCH instance) can include at least one idle symbol. Some PUSCH instances (e.g., the first nominal PUSCH instance and the second nominal PUSCH instance) can be segmented based on an idle period or an idle symbol and can be transmitted in symbols other than the idle period or the idle symbol. For example, the terminal can transmit the first nominal PUSCH instance in symbols other than the idle symbol. For another example, the terminal can transmit the second nominal PUSCH instance in symbols other than the idle symbol. Also, according to Figure 7 In the second exemplary embodiment shown in FIG. 2, the second nominal PUSCH instance can be transmitted in symbols other than the downlink symbols. In the above two conditions, the terminal can not transmit the second nominal PUSCH instance. The terminal can transmit the third nominal PUSCH instance and the fourth nominal PUSCH instance in the nominal resources. The first nominal PUSCH instance, the third nominal PUSCH instance, and the fourth nominal PUSCH instance can correspond to the first actual PUSCH instance, the second actual PUSCH instance, and the third actual PUSCH instance, respectively.

[0180] In Figure 7 In the fourth exemplary embodiment shown in FIG. 4, the resources of some PUSCH instances (e.g., the first nominal PUSCH instance and the second nominal PUSCH instance) can include at least one idle symbol. When a nominal PUSCH instance includes an idle symbol, the terminal can not transmit the corresponding nominal PUSCH instance. For example, the terminal can not transmit the first nominal PUSCH instance and the second nominal PUSCH instance. The terminal can transmit the remaining nominal PUSCH instances (e.g., the third PUSCH instance and the fourth PUSCH instance) in the nominal resources. The third nominal PUSCH instance and the fourth nominal PUSCH instance can correspond to the first actual PUSCH instance and the second actual PUSCH instance, respectively.

[0181] In an example embodiment, the terminal can receive information on a starting symbol of the first PUSCH instance, information on a duration (e.g., a number of symbols) of the first PUSCH instance, and / or information on a number of times of repeated transmission of the PUSCH (i.e., a number of PUSCH instances) from the base station through a dynamic grant or a configured grant. The time locations of the PUSCH instances other than the first PUSCH instance can be determined from the time location of the first PUSCH instance. For example, all of the PUSCH instances which are repeatedly transmitted can be consecutive in time and can have the same duration. The mapping type (e.g., Type A or Type B) of the PUSCH instances can be predetermined or can be configured to the terminal. Here, the PUSCH instances can be nominal PUSCH instances.

[0182] In case of repeated PUSCH transmission, a pattern of redundancy version (RV) values can be applied to actual PUSCH instances. For example, the RV pattern applied to the PUSCH instances can be a pattern of repetition (0, 2, 3, 1) (e.g., 0, 2, 3, 1, 0, 2, 3, 1,...). In the third example embodiment shown in FIG. 3, the RV values (0, 2, 3) can be applied to the first actual PUSCH instance, the second actual PUSCH instance, and the third actual PUSCH instance (e.g., the first nominal PUSCH instance, the third nominal PUSCH instance, and the fourth nominal PUSCH instance), respectively. Figure 7 In the third example embodiment shown in FIG. 3, the RV values (0, 2, 3) can be applied to the first actual PUSCH instance, the second actual PUSCH instance, and the third actual PUSCH instance (e.g., the first nominal PUSCH instance, the third nominal PUSCH instance, and the fourth nominal PUSCH instance), respectively. Figure 7 In the fourth example embodiment shown in FIG. 4, the RV values (0, 2) can be applied to the first actual PUSCH instance and the second actual PUSCH instance (e.g., the third nominal PUSCH instance and the fourth nominal PUSCH instance), respectively.

[0183] The above-described methods can be used for unlicensed band communications. The above-described methods can be applied to FBE or FBE operation scheme. The above-described methods can be applied to LBE or LBE operation scheme. Further, the above-described methods can be applied to PUSCH scheduled by dynamic grant (e.g., uplink grant, DCI, DCI format, etc.). Alternatively, the above-described methods can be applied to PUSCH scheduled by configured grant (e.g., configured grant resource configuration, RRC signaling, and / or DCI signaling). The above-described methods can be applied to uplink transmissions other than PUSCH. For example, the above-described methods can be used for repeated PUCCH transmission. When PUCCH is transmitted repeatedly for the same control information (e.g., UCI), the above-described methods can be applied to PUCCH instances or PUCCH resources. The above-described methods can be applied to PUCCH transmission scheduled (or triggered to be transmitted) by dynamic grant (e.g., uplink grant, downlink grant, DCI, DCI format, etc.). Alternatively, the above-described methods can be applied to semi-statically configured PUCCH transmission. The PUCCH can include scheduling request (SR), HARQ-ACK, CSI (e.g., CSI part 1, CSI part 2), and / or reference signal received power (RSRP) measurement information.

[0184] In addition, as described above, the terminal can determine some symbols as invalid symbols that cannot be used for PUSCH transmission. For example, symbols configured as downlink symbols according to a semi-static slot format configuration and / or symbols in which an SS / PBCH block is transmitted can be regarded as invalid symbols. For another example, when an FBE operation scheme is used, idle symbols can be regarded as invalid symbols. Further, a set of invalid symbols can be explicitly configured to the terminal by the base station. The terminal can regard symbols that are not regarded as invalid symbols as valid symbols that can be used for PUSCH transmission.

[0185] When a nominal PUSCH instance allocated to a terminal includes invalid symbols, the nominal PUSCH instance can be converted into one or more actual PUSCHs. Each actual PUSCH instance can consist of different consecutive valid symbols within a period of the nominal PUSCH instance. For example, a nominal PUSCH instance can be allocated to 4 consecutive symbols having indices 0 to 3. When a symbol having index 1 among the 4 consecutive symbols is determined to be an invalid symbol, the nominal PUSCH instance can be converted into two actual PUSCH instances. A first actual PUSCH instance can be allocated to a symbol having index 0, and a second actual PUSCH instance can be allocated to two consecutive symbols having indices 2 and 3. When a nominal PUSCH instance is segmented into actual PUSCH instance(s), a terminal can transmit the actual PUSCH instance(s) instead of the nominal PUSCH instance. In addition, an actual PUSCH instance having a duration less than or equal to a reference value can be discarded. For example, the reference value can be one symbol. In this case, in the above example embodiment, the first actual PUSCH instance can be discarded, and only the second actual PUSCH instance can be transmitted. When a PUSCH is repeatedly transmitted (for example, when multiple PUSCH instances are allocated for the same TB), the above-described method can be applied.

[0186] [UpLink Transmission at FFP Boundary]

[0187] Figure 8 is a conceptual diagram illustrating a first exemplary embodiment of a method for uplink transmission near an FFP boundary.

[0188] Referring to Figure 8 , a terminal can transmit an uplink signal in an uplink symbol and / or a flexible symbol of a slot. In addition, an idle period can be set at an end portion of each FFP (for example, before a boundary of an FFP). In this case, a time delay of uplink transmission can increase near an FFP boundary. A terminal cannot perform uplink transmission in an idle period (for example, an idle symbol). Accordingly, uplink transmission of a terminal can be delayed by a length of an idle period or a time corresponding to an idle period. In addition, in order to acquire a shared COT at a start portion of a COT (or an FFP) initiated by a base station, a terminal can perform an operation of receiving a COT acquisition signal. A terminal can not be able to perform uplink transmission within a corresponding COT until the terminal receives and detects a COT acquisition signal (for example, until a time determined by (method 100)). In addition, a terminal can not be able to perform uplink transmission until an uplink symbol and / or a flexible symbol. Accordingly, uplink transmission can be delayed.

[0189] As a method for solving the above problem, in the FBE operation scheme, a terminal can perform the operation of a transmission node (e.g., a communication node that initiates a COT). When an LBT operation is successful for a channel in an idle period (e.g., a sensing period, a sensing time slot, a previous period of a COT), the terminal (e.g., an FBE, a terminal performing an FBE operation scheme) can initiate a COT, and can transmit an uplink transmission burst to a base station from the start time of the COT. The time position of the idle period or the period in which the terminal performs a sensing operation within the idle period can be determined according to information on the transmission timing (e.g., timing advance (TA)) of the terminal. The COT initiated by the terminal can be shared with the base station. In this case, the base station can transmit a downlink transmission burst to the terminal within the shared COT. The above-described method can be referred to as (Method 200).

[0190] The FFP for the case where the transmission node is a terminal (hereinafter, referred to as "uplink FFP") can be distinguished from the FFP for the case where the transmission node is a base station (hereinafter, referred to as "downlink FFP"). The terminal can receive information on the downlink FFP from the base station. The terminal can receive information on the uplink FFP (e.g., the FFP for the case where the transmission node is a terminal) from the base station. The information on the uplink FFP can include at least information corresponding to the above-described information on the downlink FFP (e.g., the period of the uplink FFP or the length of the uplink FFP). In addition, the information on the uplink FFP can include information on the time offset of the FFP. The time offset can be commonly applied to all FFPs. In addition, the time offset can be an offset between the start time of the FFP (e.g., the first FFP after the reference time) and the reference time (e.g., the start time of every other radio frame).

[0191] The configuration unit (e.g., granularity) of the time offset can be Ns slots or Nb symbols. Each of Ns and Nb can be a natural number. For example, Ns can be 1, and Nb can be 1. When a plurality of subcarrier spacings are configured (e.g., used) in a carrier (or bandwidth part) in which the uplink FFP is configured, the time offset can refer to a slot or a symbol for a specific subcarrier spacing. For example, the specific subcarrier spacing can be configured from the base station to the terminal. Alternatively, the specific subcarrier spacing can be the smallest (or largest) subcarrier spacing among the subcarrier spacings configured in the carrier (or bandwidth part). Alternatively, the specific subcarrier spacing can be a subcarrier spacing configured in an activated bandwidth part (e.g., an activated downlink bandwidth part or an activated uplink bandwidth part). The above-described method of applying the time offset of the FFP can be equally applied to the downlink FFP. In addition, the information on the time offset of the downlink FFP can be included in the information on the downlink FFP and can be signaled to the terminal.

[0192] The time offset for the uplink FFP can be a value including the TA of the terminal. Alternatively, the time offset for the uplink FFP can be a value not including the TA of the terminal. In this case, the actual period in which the terminal performs the sensing operation in the idle period of the uplink FFP and the actual time in which the terminal transmits a signal in the COT of the uplink FFP can be a time advanced by the TA of the terminal. Alternatively, the information on the uplink FFP can additionally include the TA of the terminal or a time offset corresponding to the TA of the terminal, and the terminal can determine the time position of the uplink FFP based on the information on the uplink FFP.

[0193] The information on the uplink FFP can be included in system information (e.g., SIB1) transmitted to the terminal. In addition, the information on the uplink FFP can be transmitted to the terminal through RRC signaling (e.g., RRC signaling specific to the terminal, RRC signaling specific to the cell). The terminal can receive a plurality of configuration information on the uplink FFP through a plurality of signaling schemes (e.g., SIB1 and RRC signaling specific to the terminal). In this case, the terminal can select one configuration information (e.g., configuration information received through RRC signaling specific to the terminal) from among the plurality of configuration information based on a predetermined priority, and can configure the uplink FFP based on the selected configuration information.

[0194] In an exemplary embodiment, the COT and the idle period constituting the downlink FFP can be referred to as a "downlink COT" and a "downlink idle period", respectively. The COT and the idle period constituting the uplink FFP can be referred to as an "uplink COT" and an "uplink idle period", respectively.

[0195] Figure 9 is a conceptual diagram illustrating a second exemplary embodiment of a method for uplink transmission near an FFP boundary.

[0196] Referring to Figure 9 , the terminal can transmit an uplink signal in an uplink symbol and / or a flexible symbol of a slot. The terminal can receive configuration information of a slot format and configuration information of an uplink FFP (i.e., UL FFP) from the base station. That is, the slot format and the uplink FFP can be configured to the terminal. For example, the uplink FFP can be shifted by a time offset configured by the base station, and an uplink FFP boundary (e.g., a boundary of a first uplink FFP and a second uplink FFP) can be located in the middle of a slot (e.g., a second slot). The terminal can not perform uplink transmission in an idle period (e.g., an idle symbol) and / or a downlink symbol (e.g., a semi-statically configured downlink symbol). Accordingly, the uplink transmission of the terminal can be delayed.

[0197] For example, the terminal can not be able to perform uplink transmission in the downlink symbol and the idle symbol arranged at the beginning part of the second slot. On the other hand, when the terminal succeeds in CCA in the idle period of the first uplink FFP, the terminal can initiate a COT in the second uplink FFP, and can transmit an uplink signal from the beginning part of the COT of the second uplink FFP. For example, the terminal can perform uplink transmission after the idle period of the second slot. For uplink transmission of the terminal, the COT initiated by the base station does not need to be shared with the terminal. Thus, a time delay of uplink transmission of the terminal can be reduced.

[0198] In an example embodiment, when a slot format is configured to a terminal, a beginning period (e.g., a symbol set including at least a first symbol) of an uplink FFP (or COT) can be an uplink symbol (e.g., a semi-statically configured uplink symbol, an uplink symbol configured by an SFI) or a flexible symbol (e.g., a semi-statically configured flexible symbol, a flexible symbol configured by an SFI). The terminal can not expect the beginning period (e.g., a symbol set including at least a first symbol) of the uplink FFP (or COT) to be a downlink symbol (e.g., a semi-statically configured downlink symbol, a downlink symbol configured by an SFI). The base station can configure an uplink FFP and / or a slot format to the terminal so that the beginning period (e.g., a symbol set including at least a first symbol) of the uplink FFP (or COT) is an uplink symbol or a flexible symbol.

[0199] Further, a symbol in which an SS / PBCH block is transmitted can not be configured as the beginning period (e.g., a symbol set including at least a first symbol) of the uplink FFP (or COT). Here, the symbol in which the SS / PBCH block is transmitted can refer to "a symbol in which the SS / PBCH block is actually transmitted" or "a symbol configured by the base station as a symbol in which the SS / PBCH block is actually transmitted". The terminal can receive the SS / PBCH block by performing rate matching of a PDSCH with respect to the SS / PBCH block. Further, a symbol in which a Type 0-PDCCH CSS set is configured can not be configured as the beginning period (e.g., a symbol set including at least a first symbol) of the uplink FFP (or COT). The Type 0-PDCCH CSS set can be configured to the terminal through a PBCH or cell-specific RRC signaling.

[0200] Optionally, the terminal can not perform a channel access operation and / or a COT initiation operation for the corresponding uplink FFP when a starting period (e.g., a symbol set including at least a first symbol) of the uplink FFP (or COT) is a symbol configured as a downlink symbol, a symbol in which an SS / PBCH block is transmitted, and / or a symbol of a configured Type 0 PDCCH CSS set. The base station can not instruct the terminal to perform a channel access operation and / or a COT initiation (e.g., using a dynamic indication of a DCI) when a starting period (e.g., a symbol set including at least a first symbol) of the uplink FFP (or COT) is a symbol configured as a downlink symbol, a symbol in which an SS / PBCH block is transmitted, and / or a symbol of a configured Type 0 PDCCH CSS set.

[0201] In an example embodiment, the terminal can perform a CCA in an idle period (e.g., a sensing period, a sensing slot, a previous period of a next COT, etc.) regardless of a slot format of the idle period of the uplink FFP. That is, the terminal can perform a CCA in a corresponding idle period even when a format or a transmission direction of at least a portion of symbols corresponding to the idle period of the uplink FFP (e.g., symbols corresponding to a sensing period, a sensing slot, and / or a previous period of a next COT) is one of a downlink, flexible, and uplink. Similarly, the base station can perform a CCA in an idle period (e.g., a sensing period, a sensing slot, and / or a previous period of a next COT) regardless of a slot format of the idle period of the downlink FFP.

[0202] Optionally, the terminal can not perform a CCA in an idle period when the terminal performs an uplink operation in the idle period (e.g., a sensing period, a sensing slot, a previous period of a next COT, etc.) of an uplink FFP. For example, when both a downlink FFP and an uplink FFP are configured to the terminal, a COT initiated by the base station in an idle period of the uplink FFP is shared with the terminal, and an uplink transmission is configured (or instructed) to be performed in the shared COT, the terminal can not perform a sensing operation in a corresponding idle period. The uplink FFP can be an uplink FFP in which a corresponding channel is not occupied by the terminal. Optionally, the uplink FFP can be an uplink FFP in which a corresponding channel is occupied by the terminal and a COT is initiated by the terminal.

[0203] Specifically, when performing an uplink operation in at least a part of an idle period or a sensing slot in the idle period of the uplink FFP, the terminal can not perform a CCA in the corresponding period. Similarly, when performing switching from downlink to uplink or from uplink to downlink in an idle period (e.g., a sensing period, a sensing slot, a previous period of a next COT, etc.) of the uplink FFP, the terminal can not perform a CCA in the idle period. The switching time can be predefined in a technical specification. Further, when performing an inter-frequency or inter-cell measurement operation in an idle period (e.g., a sensing period, a sensing slot, a previous period of a next COT, etc.) of the uplink FFP, or when the terminal is configured to perform an inter-frequency or inter-cell measurement operation in the idle period of the uplink FFP, the terminal can not perform a CCA in the idle period. In the above cases, the terminal can not occupy a channel in a next FFP of the FFP skipping CCA.

[0204] Figure 10 is a conceptual diagram illustrating an exemplary embodiment of an uplink FFP initiation method of a terminal.

[0205] Referring to Figure 10 , the terminal can receive configuration information of an uplink FFP from a base station, and can perform an operation as an initiating node in a channel of the uplink FFP. Further, the terminal can receive configuration information of a downlink FFP from the base station, and can perform an operation as a receiving node in a channel of the downlink FFP. The boundary of the uplink FFP and the boundary of the downlink FFP can not be aligned with each other. Channel access and transmission operations based on both the uplink FFP and the downlink FFP will be described below.

[0206] The terminal can perform a channel sensing operation in an idle period of a first uplink FFP in order to initiate a COT in a second uplink FFP. An operation of performing a first uplink transmission in the idle period of the first uplink FFP can be configured (e.g., indicated) to the terminal. In this case, the terminal can perform the first uplink transmission. A COT initiated by the base station in a first downlink FFP can be shared with the terminal, and the terminal can perform the first uplink transmission based on the shared COT. In this case, based on the above-described method, the terminal can not perform a sensing operation for COT initiation of the second uplink FFP in the idle period of the first uplink FFP, and can not initiate the COT in the second uplink FFP.

[0207] In the first exemplary embodiment and the second exemplary embodiment shown in Figure 10 , the first uplink transmission can overlap with a period (e.g., a sensing period, a sensing slot) in which the terminal actually performs a sensing operation in the idle period of the first uplink FFP. In the first exemplary embodiment and the second exemplary embodiment shown in Figure 10In the third exemplary embodiment shown in FIG. 13, the first uplink transmission can overlap with an idle period of the first uplink FFP, and the first uplink transmission can not overlap with a period in which the terminal actually performs a sensing operation (e.g., a sensing period, a sensing slot). In this case, as another method, the terminal can perform a sensing operation in the above period, and initiate a COT in the second uplink FFP based on a result of the sensing operation.

[0208] In Figure 10 In the first exemplary embodiment shown in FIG. 12, the first uplink transmission and the second uplink transmission can be consecutive. Optionally, a gap between the first uplink transmission and the second uplink transmission can be less than or equal to a reference value (e.g., 16 µs). In this case, the terminal can form a certain gap between the first uplink transmission and the second uplink transmission, and can not transmit a signal in the gap period. The terminal can perform a channel sensing operation in the gap period, and can initiate a COT in the next uplink FFP. The gap period can be a part of a period for the first uplink transmission (e.g., a last part period of the first uplink transmission). That is, the terminal can skip transmission in a part of a period for the first uplink transmission. The base station can indicate (e.g., configure) the terminal to perform the above operation through a signaling procedure. A length of the gap period can correspond to the reference value (e.g., 16 µs). Optionally, the length of the gap period can be a value different from the reference value. For example, the length of the gap period can be defined as a value greater than the reference value. Optionally, the length of the gap period can be set by the base station.

[0209] The operation of performing an uplink transmission in a start period (e.g., a symbol set including at least a first symbol) of an uplink FFP (or a COT) can be configured (e.g., indicated) to the terminal. In this case, the terminal can initiate a COT and can perform an uplink transmission in the initiated COT. The uplink transmission can be a valid uplink transmission (e.g., an uplink transmission in which the terminal generally performs a transmission operation). The uplink transmission can be included in a corresponding uplink FFP (or COT). The uplink transmission can be a semi-statically configured uplink transmission (e.g., a configured grant PUSCH, a periodic PUCCH, a periodic / semi-persistent SRS, a PRACH, etc.). Optionally, the uplink transmission can be a dynamically scheduled uplink transmission (e.g., a PUSCH, a PUCCH, an SRS, etc.). The uplink transmission can refer to a PUSCH transmission corresponding to one configured grant PUSCH resource. In the case of a repetition transmission, the uplink transmission can refer to each repetition (e.g., each PUSCH instance, each PUCCH instance).

[0210] On the other hand, even when an operation of performing an uplink transmission in a starting period (e.g., a symbol set including at least a first symbol) of an uplink FFP (or COT) is configured (e.g., indicated) to the terminal, the terminal can not initiate the corresponding COT if the uplink transmission is invalid. For example, when the period of the uplink transmission includes a downlink symbol and / or a flexible symbol, or when the period of the uplink transmission overlaps with an idle period in which the uplink transmission cannot be performed, the uplink transmission can be considered invalid.

[0211] When an operation of performing an uplink transmission in a starting period (e.g., a symbol set including at least a first symbol) of an uplink FFP (or COT) is not configured (e.g., indicated) to the terminal, the terminal can not initiate the corresponding COT. Also, when an operation of performing an uplink transmission in a starting period (e.g., a symbol set including at least a first symbol) of an uplink FFP (or COT) is not configured (e.g., indicated) to the terminal, the terminal can not expect to be instructed (e.g., by dynamic indication using DCI) by the base station to perform a channel access operation and / or COT initiation for the corresponding uplink FFP.

[0212] Additionally or optionally, when an operation of performing a downlink reception and / or an operation for switching between downlink and uplink in a starting period (e.g., a symbol set including at least a first symbol) of an uplink FFP (or COT) is configured (e.g., indicated) to the terminal, the terminal can not initiate the corresponding COT. Also, when an operation of performing a downlink reception and / or an operation for switching between downlink and uplink in a starting period (e.g., a symbol set including at least a first symbol) of an uplink FFP (or COT) is configured (e.g., indicated) to the terminal, the terminal can not expect to be instructed (e.g., by dynamic indication using DCI) by the base station to perform a channel access operation and / or COT initiation for the corresponding uplink FFP.

[0213] In the above operation, even when the sensing operation is successful in the previous uplink idle period, the terminal can not initiate the COT. Alternatively, in the above case, the terminal can skip the sensing operation in the previous uplink idle period. The uplink transmission can include transmission of PUSCH, PUCCH, SRS, DM-RS, etc. Also, the uplink transmission can include transmission of PRACH.

[0214] In addition, as described above, both the base station and the terminal can perform operations as a transmitting node in a channel. The downlink FFP-based channel access operation and the uplink FFP-based channel access operation can be performed together or simultaneously. The terminal (or the base station) can initiate a COT in a certain period, can transmit a signal in the initiated COT, can acquire a shared COT initiated by the base station (or the terminal) in another period, and can transmit a signal in the shared COT.

[0215] The base station can configure a downlink FFP and / or an uplink FFP to the terminal. That is, the terminal can receive information on the downlink FFP and / or information on the uplink FFP from the base station. The downlink FFP and / or the uplink FFP configured to the terminal can be activated or deactivated through signaling (e.g., MAC CE signaling, DCI signaling, RRC signaling, etc.) from the base station. The base station and the terminal can perform a channel access operation based on the activated FFP. The above-described method can be referred to as (method 210). Unless otherwise specified in an exemplary embodiment, operations and configurations related to the downlink FFP and the uplink FFP can be applied to the same channel.

[0216] The downlink FFP and the uplink FFP can be aligned with each other. The boundary of the downlink FFP can coincide in time with the boundary of the uplink FFP. On the other hand, the downlink FFP and the uplink FFP can not be aligned with each other. For example, a time offset can be configured between the downlink FFP and the uplink FFP. The time offset can be a time interval (or information corresponding to the time interval) from a reference time to the start time of any one of the downlink FFPs or any one of the uplink FFPs. Different time offsets from the reference time can be applied to the downlink FFP and the uplink FFP. The reference time can be the boundary of an even radio frame. Alternatively, the reference time can be the boundary of each radio frame. Different reference times can be applied to the downlink FFP and the uplink FFP. The time offset of the downlink FFP can be fixed to 0. On the other hand, the time offset of the uplink FFP can have various values. For example, the time offset of the uplink FFP can be set to A symbols and / or B slots. Each of A and B can be a natural number.

[0217] In this case, the symbol and / or slot can be a symbol and / or slot according to a specific bandwidth part (hereinafter, referred to as a "reference bandwidth part") and a numerology configured to a corresponding carrier (hereinafter, referred to as a "reference numerology"). Different numerologies (e.g., subcarrier spacing and / or CP length) can be configured to a plurality of bandwidth parts configured in one carrier, and a specific bandwidth part among the plurality of bandwidth parts can be used as the reference bandwidth part. For example, the reference bandwidth part and / or the reference numerology (or reference subcarrier spacing) can be configured to the terminal by the base station. The reference bandwidth part and / or the reference numerology can be transmitted to the terminal together with the FFP configuration information (e.g., configuration information of the uplink FFP).

[0218] For another example, the reference bandwidth part and / or the reference numerology (or reference subcarrier spacing) can be determined through a predefined condition. For example, the reference bandwidth part can be a bandwidth part having the smallest (or largest) subcarrier spacing among carriers. When bandwidth parts having the same subcarrier spacing and different CP lengths are configured, a bandwidth part having a normal CP (or an extended CP) can be determined as the reference bandwidth part. The reference bandwidth part can be a downlink bandwidth part or an uplink bandwidth part. When the downlink bandwidth part and the uplink bandwidth part have different numerologies, the reference bandwidth part can be determined as the downlink bandwidth part or the uplink bandwidth part according to a predetermined condition (e.g., a bandwidth part having the smallest (or largest) subcarrier spacing).

[0219] In addition, the period (or period value) of the downlink FFP and the uplink FFP can be the same. Alternatively, the period of the downlink FFP and the uplink FFP can be different from each other. A multiple relationship can be established between the period of the downlink FFP and the period of the uplink FFP. For example, when the period of the downlink FFP (or the period of the uplink FFP) is P ms, the period of the uplink FFP (or the period of the downlink FFP) can be N×P ms. P can be a positive number, and N can be a natural number. The above multiple relationship can be established between the period of the downlink FFP and the period of the uplink FFP applied to the same channel. According to the above method, the operation and implementation complexity of the base station and the terminal in the FBE operation scheme can be reduced.

[0220] Figure 11a is a conceptual diagram illustrating a first exemplary embodiment of a method for configuring a downlink FFP and an uplink FFP, Figure 11b is a conceptual diagram illustrating a second exemplary embodiment of a method for configuring a downlink FFP and an uplink FFP.

[0221] Referring to Figure 11a and Figure 11b, downlink FFPs and uplink FFPs for a channel can be configured to a terminal. The downlink FFPs and the uplink FFPs can not be aligned with each other. In Figure 11a In an example embodiment shown in Figure 11b In an example embodiment shown in

[0222] Figure 12 is a conceptual diagram showing a third example embodiment of a method for uplink transmission near an FFP boundary.

[0223] Referring to Figure 12 , a terminal can transmit an uplink signal in an uplink symbol and / or a flexible symbol of a slot. The terminal can receive configuration information of a slot format from a base station, and can receive configuration information of downlink FFPs and uplink FFPs. The downlink FFPs and the uplink FFPs can have the same period value, and there can be a time offset between the downlink FFPs and the uplink FFPs. For example, a k-th downlink FFP can precede an l-th uplink FFP by a predetermined time (e.g., a number of symbols). k and l can be natural numbers or integers greater than or equal to 0. In a unit time, k and l can be the same as or different from each other.

[0224] For example, a boundary of a downlink FFP (e.g., a boundary between a first downlink FFP and a second downlink FFP) can be aligned with a slot boundary (e.g., a boundary between a second slot and a third slot), and a boundary of an uplink FFP (e.g., a boundary between a first uplink FFP and a second uplink FFP) can be located in the middle of a slot (e.g., the third slot). An idle period of the downlink FFP and an idle period of the uplink FFP can overlap with each other.

[0225] The terminal can not perform uplink transmission in the idle period (or idle symbol) and / or downlink symbol (e.g., semi-statically configured downlink symbol). In this case, the uplink transmission can be delayed. For example, the terminal can not perform uplink transmission in the idle symbol arranged in the end part of the second time slot and / or the start part of the third time slot. On the other hand, when the terminal successfully performs CCA in the idle period of the first uplink FFP, the terminal can initiate COT in the second uplink FFP, and can transmit an uplink signal from the start part of the COT of the second uplink FFP. For example, the terminal can perform uplink transmission after the idle period and / or downlink period of the third time slot. The COT for transmitting the uplink signal initiated by the base station can not need to be shared with the terminal. Accordingly, the time delay of the uplink transmission can be reduced.

[0226] In an exemplary embodiment, the idle period of the downlink FFP can precede the idle period of the uplink FFP. In this case, the CCA operation for the base station to initiate COT can precede the CCA operation for the terminal to initiate COT. Accordingly, the base station can arbitrarily determine whether to perform the CCA operation, and the CCA of the terminal can be successful or failed depending on whether the base station performs the CCA operation and / or occupies the channel. If necessary, the base station can initiate COT of the next FFP. That is, the base station can determine a communication node (e.g., base station, terminal) to initiate COT.

[0227] The terminal can periodically perform an LBT operation based on the uplink FFP. That is, the terminal can perform a channel sensing operation in the idle period of each uplink FFP, and can initiate COT when the channel sensing operation is successful. In addition, the terminal can perform uplink transmission in the start part of the COT initiated by the terminal. The base station can configure (e.g., indicate) the terminal to periodically (or mandatorily) perform the LBT operation for each uplink FFP. Alternatively, the base station can configure (e.g., indicate) the terminal to (mandatorily) perform the LBT operation for a specific uplink FFP. In other words, the base station can configure (e.g., indicate) the terminal not to perform the LBT operation for a specific uplink FFP. The terminal can perform the LBT operation based on the configuration or indication from the base station, and can initiate the corresponding COT when the LBT operation is successful. The above-described method can be referred to as (Method 220).

[0228] The terminal can determine whether to apply (method 220) through a signaling procedure from the base station. When not to apply (method 220), the terminal can perform an LBT operation for all uplink FFPs and can occupy a corresponding COT when a sensing operation (e.g., LBT operation) is successful. With respect to the channel, the terminal can arbitrarily determine whether to perform an LBT operation for an uplink FFP for which (method 220) is not applied. In an exemplary embodiment, the terminal can receive configuration information for a plurality of uplink FFPs from the base station. That is, a plurality of uplink FFPs can be configured to the terminal. Information on a period, a time offset, a length of a COT period, and / or a length of an idle period for each uplink FFP can be independently configured. In this case, the above-described method can be applied to each uplink FFP. For example, whether to apply (method 220) can be configured for each uplink FFP. (Method 220) can not be applied to a first uplink FFP configured to the terminal, and the terminal can perform an LBT operation for all FFPs. (Method 220) can be applied to a second uplink FFP configured to the terminal, and the terminal can selectively perform an LBT operation for an FFP configured (or indicated) by the base station. Information for configuring (or indicating) a specific uplink FFP can include an indicator for classifying a plurality of uplink FFP configurations (e.g., an index of an uplink FFP configuration).

[0229] (Method 220) can be used in combination with a specific condition. For example, when a period in which CCA is to be performed for a channel (e.g., a channel sensing period) and / or a COT period of an uplink FFP to be initiated through CCA includes a COT initiated by the base station (or a COT shared by the base station), the terminal can not perform a corresponding LBT operation. Even when it is configured to forcibly perform an LBT operation in an FFP and / or a channel, if a specific condition (e.g., a containing relationship with a period of a COT shared by the base station) is satisfied or not satisfied, the terminal can not perform an LBT operation in the corresponding FFP and / or channel.

[0230] In an exemplary embodiment, when the base station initiates a COT for a channel, or when the terminal determines that the base station initiates a COT for a channel, the terminal can not initiate a COT in a period overlapping with the corresponding COT. In an exemplary embodiment, when the base station initiates a COT for a channel, or when the terminal determines that the base station initiates a COT for a channel, the terminal can not initiate a COT in a period overlapping with the corresponding COT. In an exemplary embodiment, when the base station initiates a COT for a channel, or when the terminal determines that the base station initiates a COT for a channel, the terminal can not initiate a COT in a period overlapping with the corresponding COT. Figure 12 In an exemplary embodiment shown in FIG. 11, when the base station initiates a COT of a second downlink FFP, the terminal can not initiate a COT of a second uplink FFP. When a sensing period for initiating an uplink COT (e.g., an entire uplink idle period, a part of an uplink idle period) and / or at least a part of a corresponding uplink COT overlaps with a period of a COT shared by the base station, or when the sensing period for initiating an uplink COT and / or at least a part of a corresponding uplink COT belongs to a period of a COT shared by the base station, the terminal can not perform a corresponding LBT operation.

[0231] When the above operation is configured to the terminal by (method 220) to force the LBT operation to be performed for the uplink COT, the above operation can also be applied. In this case, the predetermined time (e.g., the above COT acquisition processing time) required for the terminal to determine whether the base station initiates (or occupies) the downlink COT can have to be ensured. To support this operation, the time offset between the start time of the downlink FFP and the start time of the uplink FFP can be configured to a sufficiently large value (e.g., a predetermined time including the COT acquisition signal reception time and / or the COT acquisition processing time).

[0232] Conversely, when the terminal initiates the COT for the channel, or when the base station determines that the terminal initiates the COT for the channel, the base station can not initiate the COT in a period overlapping the corresponding COT. When the sensing period (e.g., the entire downlink idle period, a part of the downlink idle period) for initiating the downlink COT and / or at least a part of the downlink COT overlaps the period of the COT shared by the terminal, or when the sensing period for initiating the downlink COT and / or at least a part of the corresponding downlink COT belongs to the period of the COT shared by the terminal, the base station can not perform the corresponding LBT operation. In this case, the time offset between the start time of the uplink FFP and the start time of the downlink FFP can be configured to a sufficiently large value (e.g., a predetermined time including the COT acquisition signal reception time and / or the COT acquisition processing time, etc.). The above method can be used in combination with (method 220). Alternatively, the above method can be used independently without being combined with (method 220).

[0233] In addition, in the FFP operation scheme, the COT occupied by the communication node (e.g., base station, terminal) can be terminated in advance. The base station or the terminal can release the channel, LBT subband, and / or RB set occupied by the base station or the terminal earlier than the end time of the COT (e.g., before the start time of the idle period). The transmitting node (e.g., base station or terminal) can inform the receiving node (e.g., terminal or base station) of information about the release time (e.g., end time). When the transmitting node is the base station, the information about the release time of the COT can be transmitted to the terminal through dynamic signaling (e.g., DCI, group common DCI, DCI format 2_0, etc.).

[0234] The information on the release time can include information on a remaining time of the COT. For example, the information on the remaining time of the COT can include information on a time (e.g., a number of symbols) from a time of receiving the DCI including the information on the remaining time of the COT (e.g., a slot of receiving the DCI, a symbol of receiving the DCI, or a first symbol of a slot of receiving the DCI) to a release time of the COT (e.g., an ending symbol of the COT). Alternatively, the information on the release time can include information on the release time of the COT (e.g., an ending symbol of the COT). Alternatively, the information on the release time can be obtained from a slot format indicator (SFI). For example, the terminal can consider a last slot (e.g., a last symbol of the last slot) indicated by the SFI as a COT release time of the base station.

[0235] When the information on the COT release time is not received from the transmitting node (e.g., a base station or a terminal), the receiving node (e.g., a terminal or a base station) can consider that the corresponding COT terminates before a start time of an idle period. Alternatively, when the information on the COT release time is not received from the transmitting node, the receiving node can not make any assumption on an ending time of the corresponding COT. In this case, the terminal can not know an ending time of the COT initiated by the base station. Alternatively, when the information on the COT release time is not received from the transmitting node, the receiving node can consider that the transmitting node does not occupy the corresponding COT, and can initiate the COT within the corresponding FFP period.

[0236] Figure 13 is a conceptual diagram illustrating a first exemplary embodiment of a channel access method when a downlink FFP and an uplink FFP coexist.

[0237] Referring to Figure 13 , the terminal can receive configuration information for both a downlink FFP and an uplink FFP of a channel from the base station. That is, both the downlink FFP and the uplink FFP for the channel can be configured to the terminal. A start time of the downlink FFP and a start time of the uplink FFP can be differently configured. A channel access and a transmission operation according to the downlink FFP can be simultaneously performed with a channel access and a transmission operation according to the uplink FFP. The base station can perform an LBT operation in an idle period (e.g., a first downlink idle period) of a first downlink FFP, and can acquire a COT in a second downlink FFP. The base station can transmit a downlink transmission burst from a start time point of the second downlink FFP.

[0238] In this case, the base station can terminate the COT in advance based on the above-described method. The base station can not occupy the channel acquired in the second downlink FFP until a preconfigured end time of the COT (e.g., an end time of the COT determined according to the FFP configuration, a last symbol among the symbols constituting the second downlink FFP which does not overlap with the second downlink idle period). That is, the base station can release the COT before the preconfigured end time.

[0239] The base station can release the COT acquired in the second downlink FFP before the start time of the second uplink FFP (or the start time of the first uplink idle period, the start time of the sensing slot in the first uplink idle period). In other words, the COT end time of the second downlink FFP can be before the start time of the second uplink FFP (or the start time of the first uplink idle period, the start time of the sensing slot in the first uplink idle period). The base station can inform the terminal of information about the COT release time of the second downlink FFP. For example, the base station can signal the information about the COT release time to the terminal through DCI within the COT of the second downlink FFP. When the COT initiated by the base station is terminated in advance, the base station can not perform communication based on the COT in the idle period of the downlink FFP, and the terminal can not perform communication based on the corresponding COT in the idle period of the downlink FFP.

[0240] According to the information about the COT release time received from the base station, the terminal can consider that the base station does not occupy the channel during the remaining period of the second downlink FFP (e.g., the start period of the second uplink FFP, the idle period of the first uplink FFP, and / or the sensing slot period in the idle period of the first uplink FFP). Accordingly, the terminal can perform an LBT operation in the idle period of the first uplink FFP, and when the sensing operation (e.g., LBT operation) is successful, the terminal can acquire a COT for the corresponding channel in the second uplink FFP.

[0241] The terminal can acquire information about the COT ending time point from the base station in a downlink FFP for the channel. When a sensing slot (or an entire idle period before the sensing slot) for an uplink FFP exists outside of a COT initiated by the base station (e.g., after the ending time of the COT), the terminal can initiate the COT in the uplink FFP. On the other hand, the terminal can receive a downlink transmission burst in a downlink FFP for the channel and can not receive information about the ending time of the corresponding COT. In this case, the terminal can assume that the COT initiated by the base station includes an entire period except for an idle period of the corresponding downlink FFP, and can not perform an LBT operation in an uplink idle period (e.g., a sensing slot within the uplink idle period) overlapping the corresponding COT.

[0242] When the transmitting node is a terminal, information about a release time of a COT initiated by the terminal can be transmitted to the base station through dynamic signaling (e.g., UCI, CG-UCI, etc.). The information about the COT release time can be transmitted to the base station through a PUSCH and / or a PUCCH. If it is determined based on the information about the COT release time that a starting time of a next FFP (or a previous idle period of the next FFP, a sensing slot period within the previous idle period of the next FFP) exists outside of the COT of the terminal, the base station can perform an LBT operation for the corresponding FFP and can occupy the channel according to a result of the LBT operation.

[0243] The base station can configure (e.g., indicate) the terminal to release a COT initiated by the terminal in advance. For example, the base station can transmit information related to an ending time (e.g., a specific symbol in an FFP) of the COT initiated by the terminal to the terminal, and the terminal can terminate the COT at a time indicated by the information about the ending time of the COT. The information related to the COT ending time can be transmitted to the terminal through a signaling procedure (e.g., an RRC signaling procedure, a DCI signaling procedure, etc.) with the base station. For example, the information related to the COT ending time can be transmitted to the terminal through a DCI together with information indicating that the terminal initiates the COT.

[0244] The operation of the terminal releasing the COT can be applied to all uplink FFPs. Alternatively, the operation of the terminal releasing the COT can be applied to a specific uplink FFP. The specific uplink FFP can be dynamically indicated by a DCI. Alternatively, the specific uplink FFP can be semi-statically and / or periodically configured by an RRC signaling. The COT ending time of the terminal can not be later than a reference time (e.g., a starting time of a next downlink FFP, a starting time of an idle period before the next downlink FFP, a starting time of a sensing slot in the idle period before the next downlink FFP). For example, in the case of a COT initiated by a terminal, the COT ending time of the terminal can not be later than a starting time of a next downlink FFP. Figure 13In the exemplary embodiments shown in FIGS. 13 and 14, the base station can indicate (e.g., configure) the terminal to release the COT of the second uplink FFP in advance. In this case, the COT end time can not be later than the start time of the third downlink FFP (or the start time of the idle period of the second downlink FFP, the start time of the sensing slot in the idle period of the second downlink FFP). According to the above-described method, the initiation of the COT by the base station can not be interrupted by the COT of the terminal. When the terminal terminates the COT in advance, the terminal can not perform communication in the idle period of the uplink FFP based on the COT initiated by the terminal, and the base station can not perform communication in the idle period of the uplink FFP based on the COT shared by the terminal.

[0245] Optionally, in the COT initiated by the transmitting node, the receiving node can perform a channel sensing operation, and can initiate the COT according to the result of the channel sensing operation. That is, the COT initiated by the base station and the COT initiated by the terminal can overlap with each other.

[0246] Figure 14 is a conceptual diagram showing a second exemplary embodiment of a channel access method when a downlink FFP and an uplink FFP coexist.

[0247] Referring to Figure 14 , the terminal can receive configuration information for both a downlink FFP and an uplink FFP of a channel from the base station. That is, both the downlink FFP and the uplink FFP for the channel can be configured to the terminal. The start time of the downlink FFP and the start time of the uplink FFP can be configured differently. The channel access and transmission operation according to the downlink FFP can be performed simultaneously with the channel access and transmission operation according to the uplink FFP.

[0248] The base station can initiate a COT in the second downlink FFP. In this case, based on the above-described method, the terminal can perform a channel sensing operation for the second uplink FFP within the COT initiated by the base station of the second downlink FFP, and when the channel is determined to be in an idle state, the terminal can initiate a COT in the second uplink FFP. As a result, the COT initiated by the base station and the COT initiated by the terminal can overlap with each other in a period T1. Meanwhile, the terminal can acquire sharing of the COT initiated by the base station of the second downlink FFP.

[0249] In this case, the transmission within the period T1 (or the transmission including at least a part of the period T1) can be regarded as the transmission within the shared COT. That is, for the transmission within the period T1 (or the transmission including at least a part of the period T1), the shared COT can be applied in preference to the COT initiated by the terminal. In other words, when the transmission is limited in the shared COT and / or when the terminal acquires the shared COT, the terminal can perform the transmission based on the shared COT. When the transmission is not limited in the shared COT and the transmission is included in the COT initiated by the terminal, the terminal can perform the transmission based on the COT initiated by the terminal. The above-described operation can be generally performed even when the transmission is not limited in the period T1.

[0250] Alternatively, the transmission within the period T1 (or the transmission including at least a part of the period T1) can be regarded as the transmission within the COT initiated by the terminal. That is, for the transmission within the period T1 (or the transmission including at least a part of the period T1), the COT initiated by the terminal can be applied in preference to the shared COT. In other words, when the transmission is included in the COT initiated by the terminal, the terminal can perform the transmission based on the COT initiated by the terminal. When the transmission is not included in the COT initiated by the terminal, if the transmission is included in the shared COT and / or if the terminal acquires the shared COT, the terminal can perform the transmission based on the shared COT. The above-described operation can be generally performed even when the transmission does not belong to the period T1.

[0251] As another method, according to another predefined rule, the transmission within the period T1 (or the transmission including at least a part of the period T1) can be regarded as the transmission based on one of the two COTs (e.g., the COT of the base station and the COT of the terminal). For example, the transmission can be regarded as the transmission based on the most recently initiated COT among the two COTs (or the most recently initiated COT among the COTs initiated by the terminal) or the most recently terminated COT (or the most recently terminated COT among the COTs initiated by the terminal).

[0252] As another method, the terminal can not identify which COT among the two COTs the transmission (e.g., the transmission within the period T1 or the transmission including at least a part of the period T1) is based on. For example, the terminal can perform the uplink transmission without identifying which COT the uplink transmission belongs to.

[0253] As another approach, the terminal can determine, through a signaling procedure (e.g., RRC signaling, DCI, MAC-CE, etc.) from the base station, based on which COT (or which part of a COT) to perform a transmission (e.g., a transmission within period T1 or a transmission including at least a part of period T1). For example, the terminal can obtain, through an uplink grant (e.g., DCI format 0_X (X = 0, 1, 2,...)) for scheduling a PUSCH, information indicating to transmit the PUSCH based on one of the two COTs.

[0254] In the above approach, the expression "transmission based on a certain COT", "transmission belonging to a certain COT", or "transmission being a transmission for a certain COT" can not only mean that the corresponding transmission is performed within the period of the certain COT, but also mean that the corresponding transmission is not performed in the idle period of the FFP to which the certain COT belongs. In the above approach, a plurality of approaches can be used in combination.

[0255] In the above approach, different approaches can be applied to a transmission satisfying a certain condition and a transmission not satisfying the certain condition, respectively. For example, when the boundary of the uplink FFP coincides with the start time, the base station and the terminal can consider an uplink transmission (e.g., a configured grant PUSCH, a dynamic grant PUSCH, etc.) as a transmission based on a COT (or a shared COT) initiated by the terminal. Alternatively, the base station and the terminal can consider an uplink transmission (e.g., a configured grant PUSCH, a dynamic grant PUSCH, etc.) including the first symbol of the uplink FFP as a transmission based on a COT (or a shared COT) initiated by the terminal. Through an additional predefined rule or signaling from the base station, it can be determined to perform a transmission not satisfying the above condition based on one of the two COTs.

[0256] For another example, when the boundary of the uplink FFP does not coincide with the start time, the base station and the terminal can consider an uplink transmission (e.g., a configured grant PUSCH, a dynamic grant PUSCH, etc.) as a transmission based on a COT (or a shared COT) initiated by the terminal. Alternatively, the base station and the terminal can consider an uplink transmission (e.g., a configured grant PUSCH, a dynamic grant PUSCH, etc.) not including the first symbol of the uplink FFP as a transmission based on a COT (or a shared COT) initiated by the terminal. Through an additional predefined rule or signaling from the base station, it can be determined to perform a transmission not satisfying the above condition based on one of the two COTs.

[0257] In the above method, the transmission within the transmission period T1 (or the transmission including at least a part of the transmission period T1) can be an uplink transmission (e.g., dynamic grant PUSCH, configured grant PUSCH, PUCCH, SRS, PRACH, etc.) or a downlink transmission. A start time (e.g., a start symbol) of the transmission within the transmission period T1 can be included in the transmission period T1. Generally, the transmission period T1 can represent a period in which a COT initiated by the terminal and a COT initiated by the base station (e.g., a shared COT acquired by the terminal from the base station) overlap. The transmission within the transmission period T1 (or the transmission including at least a part of the transmission period T1) can represent a transmission in the overlapping period.

[0258] Figure 15 is a conceptual diagram illustrating an exemplary embodiment of an uplink transmission method when a downlink FFP and an uplink FFP coexist.

[0259] Referring to Figure 15 , the terminal can receive configuration information of a downlink FFP and an uplink FFP from the base station. That is, the downlink FFP and the uplink FFP can be configured to the terminal. The boundary of the downlink FFP and the boundary of the uplink FFP can not be aligned with each other. The base station can initiate a COT in a first downlink FFP, and the COT initiated by the base station can be shared with the terminal. The terminal can initiate a COT in a first uplink FFP for the same channel.

[0260] The terminal can perform an uplink transmission in the corresponding channel. The uplink transmission can include a first repetition and a second repetition. For example, the uplink transmission can be a PUSCH and can include a first PUSCH instance and a second PUSCH instance. The uplink transmission can be a configured grant PUSCH or a dynamic grant PUSCH. The uplink transmission can be performed in the COT initiated by the terminal and / or the COT of the base station shared with the terminal. Alternatively, at least a part of the uplink transmission (e.g., at least one repetition or instance constituting the uplink transmission, the first repetition, the first PUSCH instance) can be included in both the COT initiated by the terminal and the shared COT of the base station.

[0261] According to the above method, the terminal can determine which COT the uplink transmission is based on. For example, in Figure 15In the first exemplary embodiment shown in FIG. 1, the starting time of the uplink transmission can be aligned with the boundary of the uplink FFP. In this case, the terminal can perform the uplink transmission based on the COT initiated by the terminal. Even in the idle period of the first downlink FFP, the terminal can perform the uplink transmission. Therefore, the terminal can transmit both the first repetition and the second repetition constituting the uplink transmission. Alternatively, the terminal can perform the uplink transmission based on the shared COT. In this case, the terminal can not perform the uplink transmission in the idle period of the first downlink FFP. Therefore, the terminal can transmit the first repetition constituting the uplink transmission, and can not transmit the second repetition constituting the uplink transmission.

[0262] For another example, in the second exemplary embodiment shown in FIG. 2, the starting time of the uplink transmission can not be aligned with the boundary of the uplink FFP. In this case, the terminal can determine, by a pre-defined rule or signaling from the base station, which COT the uplink transmission belongs to. Alternatively, in this case, the terminal can determine that the uplink transmission is based on the COT initiated by the terminal. In this case, even in the idle period of the first downlink FFP, the terminal can perform the uplink transmission. Therefore, the terminal can transmit both the first repetition and the second repetition constituting the uplink transmission. Figure 15

[0263] Figure 14 By the above method, the base station can perform the channel sensing operation for the third downlink FFP within the COT initiated by the terminal of the second uplink FFP, and initiate the COT in the third uplink FFP when the channel is determined to be in the idle state. As a result, the COT initiated by the terminal and the COT initiated by the base station can overlap with each other in the period T2. Meanwhile, the base station can acquire the shared COT initiated by the terminal of the second uplink FFP. In this case, the above method can be applied in the same way, and the transmission within the period T2 (or the transmission including at least a part of the period T2) can be performed based on one of the two COTs. For example, the transmission within the period T2 (or the transmission including at least a part of the period T2) can be regarded as the transmission based on the shared COT. Alternatively, the transmission within the period T2 (or the transmission including at least a part of the period T2) can be regarded as the transmission based on the COT initiated by the base station.

[0264] ​​Optionally, the transmission within the time period T2 (or the transmission including at least a part of the time period T2) can be considered as the transmission based on one of the two COTs according to a predefined rule. For example, the transmission can be considered as the transmission in the recently initiated COT or the recently terminated COT among the two COTs (or the recently initiated COT or the recently terminated COT among the COTs initiated by the base station). Optionally, the terminal can not identify which one of the two COTs the transmission (e.g., the transmission within the time period T2 or the transmission including at least a part of the time period T2) is for. Optionally, the terminal can determine which COT (or which part of a COT) the transmission (e.g., the transmission within the time period T2 or the transmission including at least a part of the time period T2) is performed based on through a signaling procedure (e.g., RRC signaling, DCI, MAC-CE, etc.) from the base station. In the above-described methods, a plurality of methods can be used in combination.

[0265] In the above-described methods, the transmission or the transmission within the time period T2 (or the transmission including at least a part of the time period T2) can be a downlink transmission or an uplink transmission. A start time (e.g., a start symbol) of the transmission in the time period T2 can be included in the time period T2. Generally, the time period T2 can refer to a time period in which a COT initiated by the base station and a COT initiated by the terminal (e.g., a shared COT acquired by the base station from the terminal) overlap. The transmission within the time period T2 (or the transmission including at least a part of the time period T2) can refer to the transmission in the overlapping time period.

[0266] Figure 16 is a conceptual diagram illustrating a third exemplary embodiment of an uplink transmission method when a downlink FFP and an uplink FFP coexist.

[0267] Referring to Figure 16 , the terminal can receive configuration information of a downlink FFP and an uplink FFP from the base station. That is, the downlink FFP and the uplink FFP can be configured to the terminal. The boundary of the downlink FFP and the boundary of the uplink FFP can not be aligned with each other. The terminal can initiate a COT in a first uplink FFP, and the COT initiated by the terminal can be shared with the base station. The base station can initiate a COT in a second downlink FFP for the same channel.

[0268] The terminal may perform an uplink transmission in the corresponding channel. The uplink transmission may include a first repetition and a second repetition. For example, the uplink transmission may be a PUSCH and may include a first PUSCH instance and a second PUSCH instance. The uplink transmission may be a configuration grant PUSCH or a dynamic grant PUSCH. The uplink transmission may be performed in both a COT initiated by the terminal and / or a COT of a base station shared with the terminal. At least a portion of the uplink transmission (e.g., at least one repetition or instance constituting the uplink transmission, the first repetition, the first PUSCH instance) may be included in both a COT initiated by the terminal and a COT of a base station shared with the terminal. In this case, the terminal may determine which COT the uplink transmission is based on according to the above method.

[0269] When repeated transmission is used, the uplink transmission in the above method may refer to all repetitions or all instances that constitute the uplink transmission. Figure 15 In the first and second exemplary embodiments shown in , an uplink transmission (e.g., PUSCH) may be completely included in the COT initiated by the terminal and may be partially included in the COT initiated by the base station. The first repetition (e.g., the first PUSCH instance) may be included in the COT initiated by the base station, and the second repetition (e.g., the second PUSCH instance) may not be included in the COT initiated by the base station. In this case, the terminal may consider that the uplink transmission is not included in the COT initiated by the base station and may determine which COT the uplink transmission is based on.

[0270] exist Figure 16 In the exemplary embodiment shown in , uplink transmission may be completely included in the COT initiated by the base station and may be partially included in the COT initiated by the terminal. The first repetition may be included in the COT initiated by the terminal, and the second repetition may not be included in the COT initiated by the terminal. In this case, the terminal may consider that the uplink transmission is not included in the COT initiated by the terminal and may determine which COT the uplink transmission is based on.

[0271] In the above method, uplink transmission may refer to each repetition or each instance constituting uplink transmission. The terminal may apply the above method to each repetition or each instance constituting uplink transmission. The COT corresponding to each repetition or each instance constituting uplink transmission may be determined by different methods. Figure 15 In the first and second exemplary embodiments shown in , in order to determine the COT of the first repetition (e.g., the first PUSCH instance) and the second repetition (e.g., the second PUSCH instance) for uplink transmission, different methods may be applied, and the first repetition and the second repetition may be sent based on different COTs.

[0272] For example, the terminal can transmit a first repetition of the uplink transmission based on the COT initiated by the terminal. The terminal can determine that a second repetition of the uplink transmission is based on the COT initiated by the base station (e.g., a shared COT acquired from the base station), and can not transmit the second repetition. Alternatively, the terminal can not perform the second repetition at least in the idle period of the first downlink FFP. For another example, the terminal can perform a first repetition of the uplink transmission based on the COT initiated by the base station (e.g., a shared COT acquired from the base station), and can perform a second repetition of the uplink transmission based on the COT initiated by the terminal.

[0273] When the COT initiated by the base station and the COT initiated by the terminal overlap each other, there can be contention and / or collision between the uplink transmission and the downlink transmission. Therefore, in order to prevent collision (or contention) between the uplink and the downlink, the base station can dynamically control whether the terminal performs the LBT operation for each FFP. For example, the base station can dynamically signal information about whether the terminal performs the LBT operation (or whether channel occupancy is allowed) for each FFP to the terminal. The information about whether to perform the LBT operation can be included in the DCI transmitted to the terminal. The terminal can determine whether to perform the LBT operation for the corresponding FFP based on the information about whether to perform the LBT operation.

[0274] In addition, when the receiving node (e.g., terminal) acquires a shared COT from the transmitting node (e.g., base station) in the FFP (e.g., downlink FFP), the receiving node can not be allowed to transmit a signal in the idle period (e.g., symbol overlapping with the idle period, idle symbol) of the corresponding FFP. On the other hand, when the receiving node (e.g., terminal) fails to acquire a shared COT from the transmitting node (e.g., base station) in the FFP (e.g., downlink FFP), the receiving node can be allowed to transmit a signal in the idle period (e.g., symbol overlapping with the idle period, idle symbol) of the FFP. Here, the expression "the receiving node acquires a shared COT from the transmitting node" can mean that the receiving node acquires a COT and transmits a signal in the corresponding COT. The expression "the receiving node fails to acquire a shared COT from the transmitting node" can mean that the receiving node cannot transmit a signal in the corresponding COT.

[0275] Figure 17a is a conceptual diagram illustrating a first exemplary embodiment of a signal transmission method in an idle period, and Figure 17b is a conceptual diagram illustrating a second exemplary embodiment of a signal transmission method in an idle period.

[0276] Referring to Figure 17a and Figure 17b, the base station can initiate a COT in the first downlink FFP, and can perform a transmission in the initiated COT. The COT initiated by the base station can be released early. The COT initiated by the base station can be terminated before the start time of the first uplink FFP (or a sensing slot within an idle period of a previous FFP, a sensing slot within an idle period of a previous FFP). The terminal can initiate a COT in the first uplink FFP, and can perform a transmission in the initiated COT. The first uplink FFP can overlap with the first downlink FFP. The terminal can transmit a PUSCH in the COT initiated by the terminal in the first uplink FFP.

[0277] In the example embodiment shown in Figure 17a , the terminal can perform an uplink transmission in the COT initiated by the base station. That is, the terminal can share the COT initiated by the base station in the first downlink FFP. In this case, the terminal can not transmit a signal in the idle period of the first downlink FFP. The terminal can transmit an uplink signal (e.g., a first PUSCH and a second PUSCH) in a period within the COT initiated by the terminal except for a period corresponding to the idle period of the first downlink FFP.

[0278] In the example embodiment shown in Figure 17b , the terminal can not perform an uplink transmission in the COT initiated by the base station. That is, the terminal can not share the COT initiated by the base station in the first downlink FFP. In this case, the terminal can transmit a signal in the idle period of the first downlink FFP. The terminal can transmit an uplink signal (e.g., a first PUSCH) in a period within the COT initiated by the terminal including a period corresponding to the idle period of the first downlink FFP.

[0279] As described above, a receiving node (e.g., a terminal) can dynamically determine whether to transmit a signal during an idle period of an FFP occupied by a transmitting node (e.g., a base station). The receiving node (e.g., a terminal) can be instructed (e.g., configured) to transmit or not transmit an uplink signal (e.g., a PUSCH) during a period corresponding to an idle period of the downlink FFP within a COT initiated by the terminal. In this case, the terminal can determine whether to transmit an uplink signal (e.g., a PUSCH) during a period corresponding to an idle period of the downlink FFP until a predetermined time prior to the start time of the uplink signal (e.g., PUSCH). Here, the entity that instructs (e.g., configures) the transmission of the uplink signal can be the base station (e.g., when the uplink signal is a dynamic PUSCH grant or a configuration grant PUSCH) or a higher layer of the terminal (e.g., when the uplink signal is a configuration grant PUSCH). The predetermined time can be a value corresponding to the time required for the terminal to prepare for PUSCH transmission (e.g., coding time, etc.). The predetermined time can be predefined in the technical specifications.

[0280] The uplink signal may be a PUSCH (eg, a PUSCH instance) according to a repetitive transmission (eg, a type B repetitive transmission). Figure 17b In the exemplary embodiment shown in , the first PUSCH may be a PUSCH scheduled by type B repetitive transmission. In this case, if the condition that the terminal does not transmit a signal in the idle period of the first downlink FFP is met, the first PUSCH (e.g., nominal PUSCH) may be changed to one or more PUSCHs (e.g., actual PUSCH) and transmitted in a period other than the idle period. For example, Figure 17b The first PUSCH (eg, nominal PUSCH) shown in FIG can be segmented into Figure 17a The first PUSCH and the second PUSCH (eg, actual PUSCH) shown in FIG.

[0281] The idle period of the downlink FFP in which the terminal does not transmit a signal under the above conditions may be regarded as an invalid symbol. If it is determined whether the idle period of the first downlink FFP becomes an invalid symbol by the above reference time (e.g., a time that is a predetermined time earlier than the start time of the PUSCH) is satisfied, a PUSCH transmission operation due to segmentation or change of the terminal may be performed. If the above conditions are not determined by the above reference time, the terminal may not transmit the PUSCH (e.g., a nominal PUSCH).

[0282] Additionally, for URLLC transmission, it can be beneficial in terms of transmission time delay that the base station and the terminal continuously occupy the channel. However, in the case of uplink FFP, depending on the type and form of uplink transmission configured (e.g., indicated) at the start time of the uplink FFP (or COT), e.g., a symbol set including the first symbol, it can not always be guaranteed that the COT is initiated by the terminal. For example, whether to transmit an uplink signal and / or channel can be determined by a certain condition. Specifically, whether to transmit a PRACH, a PUCCH for transmitting an SR, and / or a configured grant PUSCH can be determined by the terminal (e.g., a higher layer of the terminal). Even when the uplink signal and / or channel is configured at the start time of the uplink FFP, the terminal can initiate the corresponding COT only when the uplink signal and / or channel is actually transmitted. When the terminal does not transmit the uplink signal and / or channel, the terminal can not initiate the corresponding COT. In the uplink FFP, the COT of the terminal can be conditionally initiated. If the terminal does not initiate the COT, the channel can not be occupied in the FFP period, and transmission delay can occur.

[0283] As a method for solving the above problem, the base station can dynamically trigger the uplink FFP for which the terminal initiates the COT. The terminal can receive information indicating the uplink FFP for which the COT is initiated from the base station. In this case, the terminal can perform a sensing operation (e.g., perform a sensing operation in an idle period of a previous uplink FFP) with respect to the uplink FFP indicated by the base station, and when the sensing operation is successful, the terminal can initiate the corresponding COT and transmit an uplink signal at the start time of the initiated COT. The information indicating the COT initiation (e.g., information indicating the uplink FFP for which the COT is initiated) can be transmitted to the terminal through an explicit method or an implicit method. The information indicating the COT initiation can be transmitted through DCI. In an exemplary embodiment, the information indicating the COT initiation can be referred to as a "COT initiation indicator". The above-described method can be referred to as (method 300).

[0284] In (method 300), the uplink signal for initiating the COT can include a PUSCH through a dynamic grant. In this case, the COT initiation indicator can be an uplink grant (e.g., DCI format 0_0, 0_1, 0_2,...) for scheduling the PUSCH. The PUSCH can not include uplink data (e.g., UL-SCH). That is, the PUSCH can be a dummy PUSCH for initiating the uplink COT, not for transmitting uplink data or control information. The terminal can determine whether the scheduled PUSCH is a dummy PUSCH by analyzing a specific field value or a code point of a specific field of the uplink grant.

[0285] The uplink signal to initiate the COT can include an SRS (e.g., an aperiodic SRS). In this case, the COT initiation indicator can be a DCI that requests or triggers the SRS. The DCI can be a downlink DCI, an uplink DCI, or a group common DCI (e.g., DCI format 2_3). Alternatively, the DCI can have a new DCI format. The SRS can be used only to initiate the uplink COT. Alternatively, the SRS can be used not only to initiate the COT but also for other purposes (e.g., acquisition of downlink CSI, acquisition of transmission timing-related information of the terminal, etc.). The terminal can receive configuration information of an SRS resource for aperiodic SRS transmission at the start time of the uplink FFP, and when the SRS transmission is indicated, the terminal can initiate the COT by transmitting the SRS in the corresponding SRS resource. The configuration information of the SRS resource can include configuration information of a time resource (e.g., a symbol in which the aperiodic SRS is mapped). Alternatively, the configuration information of the SRS resource can not include the configuration information of the time resource.

[0286] The uplink signal to initiate the COT can include a PRACH, a PUCCH for transmitting an SR, and / or a configured grant PUSCH. When the COT initiation indicator is received from the base station, the terminal can transmit the uplink signal at the start time of the corresponding FFP. Even when the transmission of the PRACH, the SR, and / or the configured grant PUSCH is not indicated (e.g., configured) to the terminal by a higher layer, the terminal can transmit the PRACH, the PUCCH including the SR, and / or the configured grant PUSCH based on the COT initiation indicator. The uplink signal can be a dummy signal used only to initiate the uplink COT. The terminal can determine whether the uplink signal is a dummy signal by analyzing a specific field value or a codepoint of a specific field of the DCI including the COT initiation indicator.

[0287] When the COT initiation indicator is transmitted to the terminal through the DCI, the uplink FFP to which the COT initiation indicator is applied can be determined by a DCI reception processing time of the terminal or a time value corresponding to the DCI reception processing time. For example, the "start time of the uplink FFP to which the COT initiation indicator is applied" or the "start time of the sensing period corresponding to the start time of the uplink FFP (e.g., the start time of the idle period of the previous uplink FFP, the start time of the sensing slot of the idle period of the previous uplink FFP)" can be a time after a lapse of at least a predetermined time (hereinafter, referred to as "T") from the time at which the DCI is received from the terminal (e.g., the last symbol of the DCI or the end time of the last symbol of the DCI). The value of T can be predefined in the technical specification. Alternatively, the value of T can be configured to the terminal from the base station. T can be a positive number indicating a time value. Alternatively, T can be a natural number indicating the number of symbols.

[0288] When the DCI including the COT initiation indicator (e.g., the DCI corresponding to the COT initiation indicator) is transmitted in the COT of the nth uplink FFP, the uplink FFP to which the COT initiation indication is applied can be the (n+K)th uplink FFP. K can be a natural number. For example, K can be 1. K can be a value predefined in the technical specification. Alternatively, K can be signaled to the terminal from the base station. For example, K or information for the terminal to determine K can be semi-statically configured to the terminal through RRC signaling. For another example, K or information for the terminal to determine K can be included in the DCI (e.g., the DCI including the COT initiation indicator) transmitted to the terminal. That is, K or information for the terminal to determine K can be dynamically indicated to the terminal. In this case, if the distance between the start time of the preconfigured uplink FFP or the start time of the sensing period corresponding to the start time of the uplink FFP and the reception end time of the DCI is less than T, the terminal can apply the COT initiation indication to the earliest uplink FFP ensuring the time T among the next uplink FFPs of the preconfigured uplink FFP. Alternatively, in this case, the terminal can ignore the COT initiation indicator. For another example, the terminal can be configured with the index (or number) of the uplink FFP within a unit time (e.g., one radio frame or two consecutive radio frames) through RRC signaling or the DCI from the base station, and the terminal can initiate or not initiate the COT with respect to the uplink FFP having the index according to the indication of the base station.

[0289] When the DCI including the COT initiation indicator is transmitted in the COT of the downlink FFP, the uplink FFP to which the COT initiation indicator is applied can be determined in combination with one or more of the reception end time of the downlink FFP, the reception time of the DCI, the time (e.g., T) required for the terminal to obtain the trigger of the COT initiation (e.g., the COT initiation indicator) by processing the DCI, the subcarrier spacing of the downlink bandwidth part, and the subcarrier spacing of the uplink bandwidth part.

[0290] Alternatively, the COT initiation indicator can include the index of the uplink FFP to which the COT initiation indication is applied or information about the index. For example, the base station can explicitly inform the terminal of the order of the uplink FFP to which the COT initiation indication is applied within a reference time (e.g., two radio frames) through the COT initiation indicator. In addition, a time offset can be applied to the uplink FFP configuration. In this case, a certain uplink FFP can be included only partially within the reference time. In this case, whether the certain uplink FFP falls within the reference time can be determined according to whether the start time (e.g., the start symbol) of the uplink FFP falls within the reference time.

[0291] In (method 210), the idle period of the downlink FFP and the idle period of the uplink FFP can overlap each other. The communication node (e.g., base station, terminal) can not perform transmission and reception in the union period of the idle period of the downlink FFP (e.g., symbol corresponding to the idle period) and the idle period of the uplink FFP (e.g., symbol corresponding to the idle period). Alternatively, the communication node (e.g., base station, terminal) can not perform transmission and reception in the intersection period of the idle period of the downlink FFP (e.g., symbol corresponding to the idle period) and the idle period of the uplink FFP (e.g., symbol corresponding to the idle period). The terminal can perform a reception operation in at least a part (e.g., symbol not overlapping with the idle period of the downlink FFP) of the idle period of the uplink FFP (e.g., symbol corresponding to the idle period). The base station can perform a reception operation in at least a part (e.g., symbol not overlapping with the idle period of the uplink FFP) of the idle period of the downlink FFP (e.g., symbol corresponding to the idle period).

[0292] When the COT of the uplink FFP starts within the idle period of the downlink FFP, the terminal can initiate the corresponding COT. As described above, when the COT of the uplink FFP starts within the COT of the downlink FFP, the terminal can initiate the COT of the uplink FFP. When the COT of the uplink FFP starts within the COT of the uplink FFP of another terminal, the terminal can initiate the COT of the corresponding uplink FFP. When the COT of the downlink FFP starts within the COT of the uplink FFP, the base station can initiate the COT of the corresponding downlink FFP. In this case, the COT initiated by the base station and the COT initiated by the terminal can overlap each other. When an operation (e.g., transmission, reception, measurement, sensing, etc.) related to the COT of the downlink FFP and an operation (e.g., transmission, reception, measurement, sensing, etc.) related to the COT of the uplink FFP conflict at the same point in time in the overlapping period, the communication node (e.g., base station, terminal) can selectively perform one of the two operations.

[0293] A standard by which the communication node selects an arbitrary one of the operations can be determined according to a priority. The priority can include a priority between transmission directions (e.g., a priority between the downlink FFP and the uplink FFP, a priority between downlink transmission and uplink transmission, etc.), a priority between COTs (e.g., a channel access priority class for acquiring a COT, a transmission priority between signals and channels constituting a COT, etc.), a transmission priority between signals and channels, etc. Here, the transmission priority between signals and channels can refer to a transmission priority identified in a higher layer (e.g., a priority of a logical channel, a quality of service (QoS), etc.), a transmission priority identified in a physical layer, etc.

[0294] The transmission priority identified in the physical layer can represent a transmission priority assigned to a physical signal and / or a channel. When the transmission of physical signals and channels having different priorities overlap, the physical signal and / or channel having a higher priority can be transmitted preferentially, and the transmission of the physical signal and / or channel having a lower priority can be skipped. Alternatively, the physical signal and / or channel having a lower priority can be multiplexed in the physical signal and / or channel having a higher priority, and the physical signal and / or channel having a lower priority can be transmitted together with the physical signal and / or channel having a higher priority. For example, the transmission priority identified in the physical layer can be configured in two levels (e.g., a first priority and a second priority). The priority can be transmitted to the terminal through an explicit method or an implicit method through physical layer signaling (e.g., a specific field value of DCI, a radio network temporary identifier (RNTI) scrambled in the CRC of PDCCH, a search space set, etc.).

[0295] The criteria, priority, etc. for selecting any one operation can be predefined in the technical specification. Alternatively, the terminal can determine the criteria, priority, etc. for selecting any one operation through a signaling procedure (e.g., RRC signaling, physical layer signaling) from the base station.

[0296] The uplink idle period and the downlink idle period configured to the terminal can overlap. When the uplink idle period and the downlink idle period completely overlap, when the sensing slot of the uplink idle period and the sensing slot of the downlink idle period at least partially or completely overlap, or when the start time (e.g., start symbol) of the uplink FFP coincides with the start time (e.g., start symbol) of the downlink FFP, the base station and the terminal can successfully sense the same channel at the same point in time or at a similar point in time. In this case, the downlink transmission burst and the uplink transmission burst can collide.

[0297] To address the conflict issue, restrictions can be imposed on the configuration of uplink FFPs and downlink FFPs. For example, a terminal can expect that an uplink idle period (e.g., a sensing slot in an uplink idle period) and a downlink idle period (e.g., a sensing slot in a downlink idle period) are configured such that they do not overlap with each other. Alternatively, a terminal can expect that an uplink idle period (or a sensing slot in an uplink idle period) and a downlink idle period (or a sensing slot in a downlink idle period) configured (e.g., indicated) to perform an LBT operation do not overlap with each other. For another example, a time offset (e.g., a symbol offset) between a start time (e.g., a start symbol) of an uplink FFP and a start time (e.g., a start symbol) of a downlink FFP can be configured to have a non-zero value. A terminal can expect that an uplink FFP and a downlink FFP are configured such that a start time (e.g., a start symbol) of any uplink FFP and a start time (e.g., a start symbol) of any downlink FFP do not coincide. Alternatively, a time offset (e.g., a symbol offset) between a start time (e.g., a start symbol) of an uplink FFP and a start time (e.g., a start symbol) of a downlink FFP can be configured to be greater than or equal to a reference value. For example, the reference value can be L, which is a number of symbols. L can be a natural number. The reference value can be predefined in a technical specification.

[0298] Alternatively, when a conflict between a downlink transmission burst and an uplink transmission burst can occur, a terminal can not perform a sensing operation in an uplink idle period (e.g., a sensing slot in an uplink idle period). When it is determined that a base station can transmit a downlink transmission burst with a conflict possibility, a terminal can not perform a sensing operation in a corresponding uplink idle period (e.g., a sensing slot in an uplink idle period). In a case where a conflict can occur, a sensing operation of a base station can be prioritized over a sensing operation of a terminal.

[0299] In addition, in the above-described case, a terminal can receive a downlink signal from a base station. There can be a possibility that the downlink signal has been transmitted based on a COT initiated by the base station. In this case, the terminal can consider that the base station initiated the COT in a downlink FFP in which the downlink signal is received, and can transmit an uplink signal by sharing the corresponding COT. Alternatively, there can be a possibility that a COT initiated by another communication node (e.g., another terminal) is shared with the base station, and that the downlink signal has been transmitted based on the shared COT. In this case, it can be difficult for the terminal to recognize that the base station initiated the COT in a downlink FFP in which the downlink signal is received, and it can be difficult to transmit an uplink signal in a corresponding COT period. The terminal can need to distinguish between the above-described two possibilities in order to perform a suitable operation.

[0300] As a method for the above, the base station can inform the terminal of information about whether it initiated a COT in a period in which the terminal receives a downlink transmission. Additionally or optionally, the base station can configure a remaining duration of a COT initiated by itself to a specific value (e.g., 0), and can inform the terminal of the specific value. The remaining duration of the COT informed to the terminal by the base station can not match the remaining duration of the COT actually occupied by the base station. The above information can be included in a group common DCI (e.g., DCI format 2_0, etc.), and the group common DCI can be transmitted to the terminal through a PDCCH (e.g., a group common PDCCH).

[0301] According to the above methods (e.g., (method 200) and (method 210)), a time delay of an uplink transmission can be reduced, and a time delay of a downlink transmission can be increased. A COT initiated by a terminal can be shared with a base station, and the base station can have to receive an uplink signal from the terminal in the shared COT in order to transmit a downlink signal in the shared COT. An uplink signal received by the base station from the terminal for acquiring the shared COT can be referred to as an "uplink COT acquisition signal" to distinguish it from a "COT acquisition signal" received by the terminal.

[0302] An uplink physical channel (e.g., a PUSCH, a PUCCH, a PRACH, etc.) can be used as an uplink COT acquisition signal. Additionally or optionally, an uplink reference signal (e.g., an SRS, a PUSCH DM-RS, a PUCCH DM-RS, a PT-RS, etc.) can be used as an uplink COT acquisition signal. UCI can be used as an uplink COT acquisition signal. Since UCI can be transmitted by being mapped to a small number of symbols, a time required for the base station to receive an uplink COT acquisition signal can be reduced, and a time delay of an uplink transmission can be reduced.

[0303] The UCI used as the uplink COT acquisition signal can be transmitted from the terminal to the base station by using at least a part of the PUSCH resources (or piggybacked on the PUSCH). Alternatively, the UCI used as the uplink COT acquisition signal can be transmitted to the base station as a part of the PUSCH. Alternatively, the UCI used as the uplink COT acquisition signal can be transmitted to the base station on the PUCCH. The UCI can include HARQ-ACK, CSI (e.g., CSI part 1, CSI part 2), and / or SR. The UCI can be the UCI transmitted with the configured grant PUSCH using the configured grant PUSCH resources. Alternatively, the UCI can include dummy UCI. The dummy UCI can mean the UCI composed of information or values irrelevant to the operation of the base station or the terminal (nonsense). Alternatively, the UCI can include new information. For example, the UCI can include information related to whether the uplink transmission (e.g., PUSCH, PUCCH) including the corresponding UCI is a part of the COT or CO initiated by the terminal. Alternatively, any uplink signal can be used as the uplink COT acquisition signal.

[0304] The uplink COT acquisition signal can be transmitted at the beginning part of the uplink COT. Alternatively, a period in which the uplink COT acquisition signal can be transmitted can be defined or configured. The period in which the uplink COT acquisition signal can be transmitted can be a part of the period of the uplink COT. When the UCI is used as the uplink COT acquisition signal, the UCI can be piggybacked (or multiplexed) in any PUSCH or each PUSCH. For example, the UCI can be piggybacked in the PUSCH scheduled by the dynamic grant. The UCI can be piggybacked in the PUSCH scheduled by the configured grant. The UCI can be piggybacked in the PUSCH regardless of the time relationship (e.g., overlap, coexistence in a predetermined period (e.g., slot, sub-slot)) between the PUCCH including the UCI and the PUSCH. Alternatively, the UCI used as the uplink COT acquisition signal can be piggybacked (or multiplexed) in the PUSCH satisfying a specific condition. For example, the UCI used as the uplink COT acquisition signal can be piggybacked in the PUSCH transmitted at least at the beginning part of the uplink COT. The base station can receive the UCI at the beginning part of the uplink COT and share the corresponding uplink COT based on the UCI.

[0305] A "COT acquisition processing time" or "processing time for validity check of downlink transmission" for the base station can be defined. The COT acquisition processing time or the processing time for validity check of downlink transmission can be referred to as T proc,cot2 . T proc,cot2The time for the base station to process (e.g., receive or detect) the received uplink COT acquisition signal, the time for determining whether the uplink COT is acquired, and / or the time for preparing the transmission of the downlink signal can be included. When the uplink COT acquisition signal is received within the uplink COT, the base station can determine the validity of the downlink transmission in the uplink COT based on the relationship between the reception time of the COT acquisition signal (e.g., the symbol to which the uplink COT acquisition signal is mapped), the downlink transmission time (e.g., the symbol to which the downlink signal to be transmitted is mapped), and T proc,cot2 .

[0306] For example, when the uplink COT acquisition signal is received within the uplink COT, if the first symbol of the downlink transmission is not earlier than the earliest symbol after T proc,cot2 from the end time of the last symbol of the uplink COT acquisition signal received by the terminal, the base station can consider the downlink transmission to be valid. Accordingly, the base station can transmit the corresponding downlink signal. The terminal can expect to receive the downlink signal from the base station after T proc,cot2 from the end time of the last symbol of the uplink COT acquisition signal transmitted by the terminal to the base station. That is, the terminal can perform the downlink reception operation after T proc,cot2 from the end time of the last symbol of the uplink COT acquisition signal transmitted by the terminal to the base station.

[0307] Before (or in a symbol before the corresponding time) T proc,cot2 from the end time of the last symbol of the uplink COT acquisition signal transmitted by the terminal to the base station, the terminal can not perform the downlink reception operation. According to the above-described method, the power consumption of the terminal can be reduced. T proc,cot2 may be referred to as "terminal downlink reception skip time (or period)". Here, the downlink transmission can refer to the transmission of PDCCH, PDSCH, SS / PBCH block, CSI-RS, DM-RS, PT-RS, PRS, etc. The unit for the validity check of the downlink transmission can be a resource, a resource set, an instance (e.g., in the case of repeated transmission), a symbol (e.g., when a CSI-RS resource is mapped to multiple symbols), etc. T proc,cot2 may be predefined in the technical specification. Alternatively, T proc,cot2 may be configured to the terminal from the base station. For example, a higher layer signaling procedure (e.g., RRC signaling procedure) can be used to configure T proc,cot2 .

[0308] [Wideband operation]

[0309] In the FBE operation scheme, when a communication node (e.g., base station, terminal) communicates using multiple channels, the above-described LBT operation can be performed independently for each of the multiple channels. In this case, the multiple channels can be included in one bandwidth part and / or one carrier. The base station and the terminal can independently perform the FFP-based LBT operation for each of the multiple channels (e.g., multiple LBT subbands, multiple subbands, multiple RB sets) constituting the same bandwidth part.

[0310] Figure 18 is a conceptual diagram illustrating a first exemplary embodiment of a channel access method using multiple channels.

[0311] Referring to Figure 18 , the terminal can configure two LBT subbands (e.g., two RB sets, two subbands, two channels) based on the configuration information received from the base station. The two LBT subbands can be referred to as a first LBT subband and a second LBT subband. The two LBT subbands can be included in one bandwidth part and / or one carrier. In addition, the terminal can receive configuration information of a slot format for the bandwidth part and / or the carrier. That is, the slot format for the bandwidth part and / or the carrier can be configured to the terminal.

[0312] In the exemplary embodiment, the LBT operation of the base station and the terminal can be performed independently for each LBT subband. To support this operation, the base station can configure an FFP for each LBT subband. Here, the FFP can be a downlink FFP. Alternatively, the FFP can be an uplink FFP. The terminal can receive the FFP configuration information from the base station, and can configure the FFP for each LBT subband based on the FFP configuration information. The FFP configuration information can include FFP configuration information for each LBT subband. For example, at least one of information on the FFP, the length of the FFP, the arrangement position of each FFP, the arrangement position of a COT constituting each FFP, and / or the arrangement position of an idle period constituting each FFP can be configured for each LBT subband.

[0313] For example, the information on the arrangement position of each FFP can include at least the above-described information on the time offset of the FFP, and the information on the time offset of the FFP can be configured for each LBT sub-band. The time offset of the FFP applied to each LBT sub-band can be defined from a reference time (e.g., the start time of each second or even radio frame). A reference LBT sub-band (e.g., a reference RB set, a reference channel) can be defined (e.g., configured), and the time offset between the FFP of a specific LBT sub-band (e.g., a specific RB set, a specific channel) and the FFP of the reference LBT sub-band can be configured. When the specific LBT sub-band is the reference LBT sub-band, the time offset can not be configured. Alternatively, when the specific LBT sub-band is the reference LBT sub-band, the time offset can be set to 0. Through the above-described method, the terminal can receive the information on the time offset from the base station, and can determine the time position of the FFP based on the time offset.

[0314] In an exemplary embodiment, different FFP offsets can be applied between LBT sub-bands. Figure 18 In the exemplary embodiment shown in

[0315] In the exemplary embodiment shown in Figure 18 In the exemplary embodiment shown in

[0316] In an example embodiment, the concept of an idle period can be extended in two dimensions. In a particular idle period, a signal transmission restriction can be limited to a frequency resource (e.g., a channel) to which the idle period belongs, and a communication node can transmit a signal in a frequency resource (e.g., other channel) other than the frequency resource (e.g., other channel) in which signal transmission is restricted in the corresponding period. The idle period can be referred to (e.g., understood) as an "idle resource." The idle resource can be a two-dimensional resource composed of a time resource and a frequency resource. Operations (e.g., transmission / reception operations, rate matching operations, puncturing operations, measurement operations, etc.) on the idle resource can be performed based on a RB symbol unit or a RE unit, etc. For example, the idle resource can be a resource including symbols overlapping the idle period and RBs constituting an LBT subband (or RB set, subband, channel) belonging to the idle period.

[0317] A terminal can rate match a data channel (e.g., PDSCH, PUSCH) around the idle resource, and can transmit or receive the data channel (e.g., PDSCH, PUSCH). Alternatively, the terminal can perform puncturing for the data channel (e.g., PDSCH, PUSCH) in the idle resource, and can transmit or receive the data channel (e.g., PDSCH, PUSCH). The terminal can skip operations such as transmission / reception and measurement related to downlink transmission or uplink transmission overlapping the idle resource. When a particular PDCCH candidate overlaps the idle resource, the terminal can not perform a blind decoding operation for the particular PDCCH candidate.

[0318] When idle periods of multiple channels cross each other, a guard band can be inserted between two adjacent channels to secure performance of a CCA operation performed in the idle period. The guard band can be used or activated only in a part of a period. For example, the guard band can be available or activated in a period (e.g., symbol) in which at least one of two channels adjacent to the guard band belongs to an idle period. In a period in which the guard band is available or activated, a base station and a terminal can or can not transmit or receive a signal (e.g., PDSCH, PUSCH, CSI-RS, PRS, SRS, etc.) in the guard band. In a period in which the guard band is not available or not activated, the base station and the terminal can transmit or receive a signal (e.g., PDSCH, PUSCH, CSI-RS, PRS, SRS, etc.) in the corresponding guard band. When the multiple channels are channels belonging to the same carrier or the same bandwidth part, the guard band can be an intra-carrier guard band.

[0319] Figure 19 is a conceptual diagram illustrating a first example embodiment of a method for configuring a guard band.

[0320] Referring to Figure 19, the terminal can receive configuration information of the first LBT sub-band and the second LBT sub-band from the base station. That is, the first LBT sub-band and the second LBT sub-band can be configured to the terminal. The first LBT sub-band and the second LBT sub-band can belong to the same bandwidth part. In addition, the terminal can receive FFP configuration information from the base station, and can configure the FFP for each LBT sub-band based on the FFP configuration information. The FFP configuration of the first LBT sub-band and the second LBT sub-band can be the same as that of the exemplary embodiment shown in FIG. 8B. Figure 18

[0321] A guard frequency region (e.g., intra-carrier guard frequency region) can be arranged between the first LBT sub-band and the second LBT sub-band. Through the above-described method, the terminal can receive configuration information (e.g., size, location, etc.) of the guard frequency region and the LBT sub-band within the bandwidth part from the base station. The guard frequency region can be available or activated only in a part of the period. The available (or activated) period of the guard frequency region can include an idle period (e.g., symbol) of at least one LBT sub-band. In another exemplary embodiment, the available period of the guard frequency region can include a part of the idle period (e.g., symbol) of at least one LBT sub-band.

[0322] The terminal can receive information (e.g., time pattern) on the available period of the guard frequency region from the base station through a signaling procedure (e.g., RRC signaling and / or physical layer signaling). The available period of the guard frequency region can be periodically repeated. The periodicity of the available period of the guard frequency region and the location of the available period within one period can be configured to the terminal. The available period of the guard frequency region can be configured in units of symbols. The location of the available period within one period can be expressed as bitmap information corresponding to symbols. When one bandwidth part includes a plurality of guard frequency regions, the available period of the guard frequency region can be configured for each guard frequency region. The information on the available period of the guard frequency region can be transmitted to the terminal together with the information on the frequency region of the guard frequency region. Alternatively, the information on the available period of the guard frequency region can be transmitted to the terminal as separate information (e.g., separate RRC parameter). The available period of the guard frequency region can be configured for each carrier, and can be commonly applied to the bandwidth parts belonging to the carrier.

[0323] Alternatively, the available period of the guard frequency region can be determined according to a predefined rule. For example, the available period of the guard frequency region can be determined according to the location of the idle period of the LBT sub-band. Specifically, the available period of a certain guard frequency region can be determined according to the location of the idle period of the two LBT sub-bands adjacent to the certain guard frequency region. The available period of the guard frequency region can include all or a part of the symbols corresponding to the idle period.

[0324] ​Even when the LBT operation of a communication node (e.g., a base station, a terminal) for a specific FFP (or COT) fails for a specific channel, the corresponding communication node (e.g., a base station, a terminal) can transmit a discovery reference signal (DRS) or an SS / PBCH block in the corresponding FFP (or COT). That is, the DRS or the SS / PBCH block can be transmitted without being based on a COT initiated by a base station and / or a COT initiated by a terminal. In this case, the DRS or the SS / PBCH block can be transmitted in a period other than a downlink idle period. When the DRS or the SS / PBCH block includes a downlink idle period, a terminal can skip a reception operation and a measurement-related operation of the corresponding DRS or SS / PBCH block. Additionally or alternatively, the DRS or the SS / PBCH block can be transmitted in a period other than an uplink idle period. When CCA is successful in a sensing period before a transmission time of the DRS or the SS / PBCH block, a base station can transmit the DRS or the SS / PBCH block. Alternatively, the base station can immediately transmit the DRS or the SS / PBCH block at the corresponding time without performing a channel sensing operation.

[0325] The DRS can refer to a set of signals and channels for initial access of a terminal, cell search, cell selection, radio resource management (RRM), RRM reporting, etc. The DRS can basically include the SS / PBCH block. In addition, the DRS can include a CORESET (or a PDCCH search space associated with the CORESET), a PDSCH, and / or a CSI-RS, in addition to the SS / PBCH block. For example, the DRS can include a CORESET #0 (i.e., a CORESET with a CORESET ID of 0) and a PDCCH search space set #0 (i.e., a search space set with a search space set ID of 0) associated with the CORESET #0. A DCI (e.g., a DCI scheduling a PDSCH including SIB1) can be transmitted through a PDCCH candidate in resources of the PDCCH search space set #0 associated with the CORESET #0.

[0326] The method and the exemplary embodiments can be limited to a specific channel (e.g., a specific LBT subband, a specific subband, a specific RB set, a specific bandwidth part, a specific carrier, etc.).

[0327] The exemplary embodiments of the disclosure can be implemented as program instructions executable by various computers and recorded on computer-readable media. The computer-readable media can include program instructions, data files, data structures, or combinations thereof. The program instructions recorded on the computer-readable media can be designed and configured specifically for the disclosure, or can be well-known and available to those skilled in the computer software field.

[0328] Examples of computer-readable media can include hardware devices made of physical (e.g., tangible) components such as RAM, ROM, and flash memory, etc. Examples of program instructions include machine code, such as produced by a compiler, and files containing higher level code that can be executed by the computer using an interpreter. The foregoing examples of hardware devices and program instructions are examples only, and other examples of hardware devices and program instructions can be used in other embodiments of the present disclosure.

[0329] While embodiments of the present disclosure and the advantages thereof have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope of the present disclosure.

Claims

1. An operation method of a terminal in a communication system, the operation method comprising: receiving, from a base station, first configuration information of a first period in which a first channel occupancy time (COT) initiated by the terminal is located and second configuration information of a second period in which a second COT initiated by the base station is located; initiating the first COT in a first period of the first period indicated by the first configuration information; determining one COT from among the first COT and the second COT according to a predefined rule, wherein the second COT is initiated by the base station in a second period of the second period; and transmitting an uplink signal to the base station based on the one COT, wherein the first configuration information includes a time offset for the first period, the first period is periodically repeated, a position of the first period is determined by the time offset, the time offset is a number of symbols between a start time of a radio frame and a start time of a first period of the first period, the number of symbols is less than a number of symbols corresponding to a period value of the first period, and the number of symbols is determined based on a smallest subcarrier spacing among carrier configurations.

2. The operating method of claim 1, wherein, a period in which the uplink signal is transmitted is included in the first COT initiated by the terminal, and the uplink signal is transmitted based on the first COT.

3. The operating method of claim 2, wherein, the uplink signal is included in the second COT initiated by the base station, and the first COT overlaps the second COT.

4. The operating method of claim 2, wherein, the uplink signal is a configured grant (CG) physical uplink shared channel (PUSCH), and the uplink signal is allocated in a period of the first COT other than a first symbol.

5. The operating method of claim 2, wherein, a period in which the uplink signal is transmitted within the first COT includes a free period of the second period to which the second COT belongs.

6. The operating method of claim 1, wherein, the predefined rule includes receiving, from the base station, downlink control information (DCI) indicating the one COT.

7. The operating method of claim 1, wherein, the first configuration information includes information indicating a period value of the first period, the second configuration information includes information indicating a period value of the second period, and the period value of the first period is an integer resolution or an integer multiple of the period value of the second period.

8. The operating method of claim 1, wherein, the first configuration information and the second configuration information are included in a radio resource control (RRC) message transmitted to the terminal. 9.An operation method of a base station in a communication system, the operation method comprising: transmitting, to a terminal, first configuration information of a first period in which a first channel occupancy time (COT) initiated by the terminal is located and second configuration information of a second period in which a second COT initiated by the base station is located; initiating the second COT in the second period indicated by the second configuration information; receiving, from the terminal, an uplink signal based on one COT from among the second COT and the first COT initiated by the terminal, The first configuration information includes a time offset for the first period, the first period is periodically repeated, a position of the first period is determined by the time offset, the time offset is a number of symbols between a start time of a radio frame and a start time of a first cycle of the first period, the number of symbols is less than a number of symbols corresponding to a cycle value of the first period, and the number of symbols is determined based on a minimum subcarrier spacing among subcarrier spacings of a carrier configuration.

10. The operating method of claim 9, wherein, A period in which the uplink signal is received is included in the first COT initiated by the terminal, and the uplink signal is received based on the first COT.

11. The operating method of claim 10, wherein, The uplink signal is included in the second COT initiated by the base station, and the first COT overlaps the second COT.

12. The operating method of claim 10, wherein, The uplink signal is a configured grant (CG) physical uplink shared channel (PUSCH), and the uplink signal is allocated in a period of the first COT except for a first symbol.

13. The operating method of claim 10, wherein, The period in which the uplink signal is received within the first COT includes a free period of a second period to which the second COT belongs.

14. The operating method of claim 9, wherein, Downlink control information (DCI) indicating the one COT is transmitted from the base station to the terminal.

15. The operating method of claim 9, wherein, The first configuration information includes information indicating a cycle value of the first period, the second configuration information includes information indicating a cycle value of the second period, and the cycle value of the first period is an integer decomposition or an integer multiple of the cycle value of the second period.

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