KR20220033982A - Method and apparatus for uplink transmission in unlicensed band - Google Patents

Abstract

A method and apparatus for uplink transmission in an unlicensed band are disclosed. An operating method of a terminal includes the steps of: receiving first configuration information of a plurality of FFPs for channel access from a base station; receiving, from the base station, second configuration information of a CG PUSCH including a first symbol of a first FFP among the plurality of FFPs, indicated by the first configuration information; checking first information indicating whether to apply the CP extension included in the second configuration information; initiating COT in the first FFP when the first information indicates the CP extension; and transmitting the CG PUSCH to which the CP extension is applied, in the COT.

Description

Method and apparatus for uplink transmission in unlicensed band {METHOD AND APPARATUS FOR UPLINK TRANSMISSION IN UNLICENSED BAND}

The present invention relates to an uplink communication technology in a communication system, and more particularly, to an uplink transmission technology for supporting Ultra Reliable Low Latency Communication (URLLC) in an unlicensed band.

For processing of rapidly increasing wireless data, a frequency band (eg, a frequency band of 6 GHz or more) higher than a frequency band (eg, a frequency band of 6 GHz or less) of long term evolution (LTE) (or LTE-A) A communication system (eg, a new radio (NR) communication system) using The NR communication system may support a frequency band of 6 GHz or higher as well as a frequency band of 6 GHz or less, and may support various communication services and scenarios compared to the LTE communication system. For example, a usage scenario of the NR communication system may include enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), and the like. Communication technologies are needed to satisfy the requirements of eMBB, URLLC, and mMTC.

Meanwhile, in order to process rapidly increasing wireless data, communication using an unlicensed band may be used. Communication technologies currently using unlicensed bands include NR-Unlicensed (NR-U), LTE-Unlicensed (LTE-U), Licensed-Assisted-Access (LAA), and MultiFire. NR-U may support a standalone mode that provides a communication service using only an unlicensed band. It is necessary to improve a channel access method and a transmission method to effectively support the above-described usage scenario (eg, URLLC) in unlicensed band communication.

An object of the present invention for solving the above problems is to provide a method and apparatus for uplink transmission supporting Ultra Reliable Low Latency Communication (URLLC) in an unlicensed band.

In a method of operating a terminal according to a first embodiment of the present invention for achieving the above object, receiving first configuration information of a plurality of FFPs for channel access from a base station, the plurality of pieces indicated by the first configuration information Receiving second configuration information of CG PUSCH including the first symbol of the first FFP among FFPs from the base station, confirming first information indicating whether CP extension included in the second configuration information is applied when the first information indicates the CP extension, initiating COT in the first FFP, and transmitting the CG PUSCH to which the CP extension is applied in the COT.

According to the present application, the base station may transmit information indicating whether cyclic prefix (CP) extension is applied to the terminal. The UE may determine whether to apply the CP extension to a configured grant (CG) physical uplink shared channel (PUSCH) disposed in the start period of an uplink (UL) fixed frame period (FFP) based on information received from the base station. The UE may perform uplink transmission in "CG PUSCH to which CP extension is applied" or "CG PUSCH to which CP extension is not applied".

PUSCH frequency domain resources may be configured based on an interlace scheme. The PUSCH frequency domain resource may be configured in one or more listen before talk (LBT) subbands. In addition, PUSCH frequency domain resources may be frequency-hoped in units of LBT subbands.

1 is a conceptual diagram illustrating a first embodiment of a communication system.
2 is a block diagram showing a first embodiment of a communication node constituting a communication system.
3A is a conceptual diagram illustrating a first embodiment of a communication method within a COT.
3B is a conceptual diagram illustrating a second embodiment of a communication method within the COT.
4 is a conceptual diagram illustrating a first embodiment of an FFP setting method.
5 is a conceptual diagram illustrating a first embodiment of the LBT subband and guard band setting method.
6 is a conceptual diagram illustrating embodiments of a configuration grant PUSCH transmission method in consideration of CP extension.
7 is a conceptual diagram illustrating a first embodiment of a method for allocating resources in an interlace-based PUSCH frequency domain.
8 is a conceptual diagram illustrating a second embodiment of a method for allocating resources in an interlace-based PUSCH frequency domain.
9A is a conceptual diagram illustrating a first embodiment of a PUSCH frequency hopping method in units of LBT subbands.
9B is a conceptual diagram illustrating a second embodiment of a PUSCH frequency hopping method in units of LBT subbands.
9c is a conceptual diagram illustrating a third embodiment of a PUSCH frequency hopping method in units of LBT subbands.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

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

In embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B”. Also, in the embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B”.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is mentioned that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that this does not preclude the possibility of addition or existence of numbers, steps, operations, components, parts, or combinations thereof.

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

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

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

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

1, the communication system 100 is a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). In addition, the communication system 100 is a core network (core network) (eg, S-GW (serving-gateway), P-GW (packet data network (PDN)-gateway), MME (mobility management entity)) may include more. When the communication system 100 is a 5G communication system (eg, a new radio (NR) system), the core network is an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc. may include

The plurality of communication nodes 110 to 130 may support a communication protocol (eg, an LTE communication protocol, an LTE-A communication protocol, an NR communication protocol, etc.) defined in a 3rd generation partnership project (3GPP) standard. A plurality of communication nodes 110 to 130 are CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division) technology multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA Technology, Non-orthogonal Multiple Access (NOMA) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (Space Division Multiple Access) technology, etc. can support Each of the plurality of communication nodes may have the following structure.

2 is a block diagram illustrating a first embodiment of communication nodes constituting a communication system.

Referring to FIG. 2 , the communication node 200 may 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 may further include an input interface device 240 , an output interface device 250 , a storage device 260 , and the like. Each of the components included in the communication node 200 may be connected by a bus 270 to communicate with each other.

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

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

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

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

Meanwhile, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other through an ideal backhaul link or a non-ideal backhaul link. , information can be exchanged with each other through an ideal backhaul link or a non-ideal backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to the core network through an ideal backhaul link or a non-ideal backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to the corresponding terminals 130-1, 130-2, 130-3, 130 -4, 130-5, 130-6), and the signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) is transmitted to the core network can be sent to

In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits MIMO (eg, single user (SU)-MIMO, multi user (MU)- MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, direct communication between terminals (device to device communication, D2D) (or , Proximity Services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), and the like may be supported. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 is the base station 110-1, 110-2, 110-3, and 120-1. , 120-2) and corresponding operations, and operations supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be performed. For example, the second base station 110 - 2 may transmit a signal to the fourth terminal 130 - 4 based on the SU-MIMO method, and the fourth terminal 130 - 4 uses the SU-MIMO method. A signal may be received from the second base station 110 - 2 . Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 based on the MU-MIMO scheme, and the fourth terminal 130-4. and each of the fifth terminals 130 - 5 may receive a signal from the second base station 110 - 2 by the MU-MIMO method.

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, and the fourth The terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by the CoMP method. A plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) each of the terminals (130-1, 130-2, 130-3, 130-4) belonging to its own cell coverage , 130-5, 130-6) and the CA method can transmit and receive signals. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 controls D2D between the fourth terminal 130-4 and the fifth terminal 130-5. and each of the fourth terminal 130-4 and the fifth terminal 130-5 may perform D2D under the control of the second base station 110-2 and the third base station 110-3, respectively. .

Methods for transmitting and receiving signals in a communication system will be described. In particular, information on a channel occupation method, a signal transmission method, and a channel occupation of a communication node (eg, a base station and/or a terminal) for improving transmission reliability and delay time in a wireless communication system that supports communication in an unlicensed band A method of transmitting and receiving, etc. may be described. The following embodiments may be applied to not only the NR communication system but also other communication systems (eg, an LTE communication system, a fifth generation (5G) communication system, a sixth generation (6G) communication system, etc.).

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

Numerology applied to physical signals and channels in a communication system (eg, an NR communication system) may vary. Numerology can be varied to meet various technical requirements of a communication system. In a communication system to which a cyclic prefix (CP)-based OFDM waveform technology is applied, the numerology may include a subcarrier interval and a CP length (or CP type). Table 1 may be a first embodiment of a pneumatology configuration for a CP-OFDM based communication system. The subcarrier intervals may have a relationship of a power of two to each other, and the CP length may be scaled at the same rate as the OFDM symbol length. According to the frequency band in which the communication system operates, at least some of the pneumatologies of Table 1 may be supported. In addition, in the communication system, neurology(s) not listed in Table 1 may be further supported. For a specific subcarrier spacing (eg, 60 kHz), CP type(s) not listed in Table 1 (eg, extended CP) may be additionally supported.

In the following, a frame structure of a communication system will be described. Elements constituting a frame structure in the time domain may include a subframe, a slot, a mini-slot, a symbol, and the like. A subframe may be used as a unit of transmission, measurement, etc., and the length of the subframe may have a fixed value (eg, 1 ms) regardless of the subcarrier interval. A slot may include consecutive symbols (eg, 14 OFDM symbols). The length of the slot may be variable, different from the length of the subframe. For example, the length of the slot may be inversely proportional to the subcarrier spacing.

The slot may be used in units of transmission, measurement, scheduling, resource configuration, timing (eg, scheduling timing, hybrid automatic repeat request (HARQ) timing, channel state information (CSI) measurement and reporting timing, etc.). The length of the actual time resource used for transmission, measurement, scheduling, resource setting, etc. may not match the length of the slot. The mini-slot may include consecutive symbol(s), and the length of the mini-slot may be shorter than the length of the slot. The mini-slot may be used in units of transmission, measurement, scheduling, resource configuration, timing, and the like. A mini-slot (eg, a mini-slot length, a mini-slot boundary, etc.) may be predefined in a technical specification. Alternatively, a mini-slot (eg, a mini-slot length, a mini-slot boundary, etc.) may be configured (or indicated) in the terminal. When a specific condition is satisfied, it may be configured (or indicated) in the terminal that the mini-slot is used.

The base station may schedule a data channel (eg, a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), a physical sidelink shared channel (PSSCH)) using some or all of the symbols constituting the slot. . In particular, for URLLC transmission, unlicensed band transmission, transmission in a coexistence situation of an NR communication system and an LTE communication system, and multi-user scheduling based on analog beamforming, the data channel may be transmitted using a portion of the slot. Also, the base station may schedule the data channel using a plurality of slots. Also, the base station may schedule the data channel using at least one mini-slot.

Elements constituting the frame structure in the frequency domain may include a resource block (RB), subcarriers, and the like. One RB may include consecutive subcarriers (eg, 12 subcarriers). The number of subcarriers constituting one RB may be constant irrespective of the pneumatology. In this case, the bandwidth occupied by one RB may be proportional to the subcarrier spacing of the Numerology. The RB may be used as a transmission and resource allocation unit such as a data channel and a control channel. Resource allocation of the data channel may be performed in units of RBs or RB groups (eg, resource block group (RBG)). One RBG may include one or more consecutive RBs. Resource allocation of the control channel may be performed in units of control channel elements (CCEs). In the frequency domain, one CCE may include one or more RBs.

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

A slot may include one or more flexible sections. Alternatively, the slot may not include a flexible section. The terminal may perform a predefined operation in the flexible section. Alternatively, the terminal may perform a semi-static or periodically set operation by the base station in the flexible section. For example, the operation periodically set by the base station is a PDCCH (physical downlink control channel) monitoring operation, SS/PBCH (synchronization signal/physical broadcast channel) block reception and measurement operation, CSI-RS (channel state information-reference signal) Reception and measurement operation, reception operation of downlink semi-persistent scheduling (SPS) PDSCH, sounding reference signal (SRS) transmission operation, physical random access channel (PRACH) transmission operation, PUCCH transmission operation configured periodically, configuration grant ) may include a PUSCH transmission operation according to the The flexible symbol may be overridden by a downlink symbol or an uplink symbol. When the flexible symbol is overridden by the downlink or uplink symbol, the terminal may perform a new operation instead of the existing operation on the corresponding flexible symbol (eg, an overridden flexible symbol).

The slot format may be semi-statically configured by higher layer signaling (eg, radio resource control (RRC) signaling). Information indicating the semi-static slot format may be included in system information, and the semi-static slot format may be cell-specifically configured. In addition, the semi-static slot format may be additionally configured for each UE through UE-specific higher layer signaling (eg, RRC signaling). A flexible symbol of a cell-specifically configured slot format may be overridden by a downlink symbol or an uplink symbol by UE-specific higher layer signaling. In addition, the slot format may be dynamically indicated by physical layer signaling (eg, a slot format indicator (SFI) included in downlink control information (DCI)). A semi-statically set slot format may be overridden by a dynamically indicated slot format. For example, a semi-statically configured flexible symbol may be overridden by a downlink symbol or an uplink symbol by SFI.

The terminal may perform a downlink operation, an uplink operation, a sidelink operation, and the like in a bandwidth part. The bandwidth portion may be defined as a set of contiguous RBs (eg, physical resource blocks (PRBs)) in a frequency domain having a specific numerology. One neurology may be used for signal transmission (eg, transmission of a control channel or a data channel) in one bandwidth portion. In embodiments, “signal” when used in a broad sense may mean any physical signal and channel. The terminal performing the initial access procedure may obtain configuration information of the initial bandwidth portion from the base station through system information. A terminal operating in an RRC connected state may obtain configuration information of a bandwidth portion from a base station through terminal-specific higher layer signaling.

The configuration information of the bandwidth part may include a numerology (eg, subcarrier spacing and/or CP length) applied to the bandwidth part. In addition, the configuration information of the bandwidth part further includes information indicating the location of the start RB (eg, start PRB) of the bandwidth part and information indicating the number of RBs (eg, PRB) constituting the bandwidth part can do. At least one bandwidth portion among the bandwidth portion(s) configured in the terminal may be activated. For example, each of one uplink bandwidth part and one downlink bandwidth part may be activated in one carrier. In a time division duplex (TDD)-based communication system, a pair of an uplink bandwidth portion and a downlink bandwidth portion may be activated. The base station may set a plurality of bandwidth portions to the terminal within one carrier, and may switch the active bandwidth portion of the terminal.

In the embodiments, "a frequency band (eg, carrier, bandwidth portion, RB set, listen before talk (LBT) subband, guard band, etc.) is activated" means "a base station or a terminal It may mean "a state in which a signal can be transmitted/received using a band (eg, an active frequency band)". In addition, "that the frequency band is activated" means "a radio frequency (RF) filter (eg, a band pass filter) of the transmitter and receiver operates in a frequency band including the corresponding frequency band (eg, active frequency band) state".

In embodiments, RB may mean a common RB (CRB). Alternatively, RB may mean PRB or virtual RB (VRB). In the NR communication system, a CRB may mean an RB constituting a set (eg, a common RB grid) of RBs that are continuous based on a reference frequency (eg, point A). Carriers, bandwidth portions, etc. may be deployed on a common RB grid. That is, a carrier, a bandwidth portion, and the like may be composed of CRB(s). An RB or CRB constituting a bandwidth portion may be referred to as a PRB, and a CRB index within the bandwidth portion may be appropriately converted into a PRB index. In an embodiment, the RB may mean an interlace RB (IRB). The IRB will be described later.

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

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

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

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

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

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

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

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

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

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

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

In order to provide a fair channel use opportunity to communication nodes in communication in an unlicensed band, a contention-based channel access scheme may be used, and related spectrum regulation conditions may be defined. For example, a transmission node (eg, a communication node performing a transmission operation) may check 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 an idle state, the transmitting node may transmit a signal by occupying the corresponding channel for a predetermined time period. The predetermined time period may be referred to as channel occupancy time (COT). On the other hand, the transmitting node may continuously perform the CCA operation when the channel is in the occupied state. The transmitting node may measure the strength of the received signal in the channel sensing period, and may determine the occupancy state of the channel by comparing the measured received signal strength with a threshold. For example, the threshold may be an energy detection threshold. The threshold may be predefined in a technical standard. Alternatively, the threshold may be set in the terminal from the base station. The above-described operation may be referred to as an LBT operation.

The LBT operation may be performed in various ways depending on the presence and absence of CCA. For example, a communication node may transmit a signal without performing CCA. This operation may be referred to as a first category LBT. For another example, the communication node may perform CCA in a sensing period having a predefined length, and may transmit a signal after the sensing period according to a result of performing CCA. Specifically, the communication node may sense a channel in at least a portion of the sensing interval (eg, at least one sensing slot), and the time at which a signal having a reception strength that is less than or equal to a threshold value is received is a reference time (eg, , 4 μs) or more, it can be determined that the channel is idle. For example, the length of the sensing section may be 25 μs, 16 μs, 9 μs, or the like. The above-described operation may be referred to as a second category LBT. In addition, since the above-described operation includes one CCA, it may be referred to as “one-shot LBT”.

Meanwhile, the length of the sensing section may be variable. The communication node may perform CCA in the initial sensing period, and may transmit a signal after the sensing period when the channel is in an idle state. On the other hand, when the channel is in the occupied state, the communication node may extend the sensing period and may perform an additional sensing operation in the extended sensing period. The sensing period may be extended by a random back-off method, and the length of the extended sensing period may be proportional to the random back-off value. The random backoff value may be determined within a contention window (CW). For example, if the random backoff value and the 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 . Each of N _init and CW _p may be an integer.

For example, the communication node may additionally perform CCA in N _init consecutive defer periods, and after the sensing period when the channel is idle in all sensing slots (eg, the entire sensing period) can send a signal to In addition, the communication node can perform a self-defer operation when the completion time of the sensing operation (eg, the time when the backoff counter value becomes 0) and the time when the signal is to be transmitted do not match. In addition, an additional sensing operation may be performed before signal transmission, and a signal may be transmitted according to a result of the additional sensing operation. In the above-described LBT operation, the initial sensing operation may be omitted. The above-described operation may be referred to as a third category LBT or a fourth category LBT. For the third category LBT, the size of the contention window may be fixed. In the case of the fourth category LBT, the size of the contention window may be adjusted according to a predetermined procedure. For example, the size of the contention window is determined by the type of signal to be transmitted, channel access priority class (CAPC), frequency regulation, success or failure of previous transmission (eg, HARQ-ACK reception), etc. can be changed.

In an NR communication system or an LTE communication system, the above-described LBT operation methods may be applied to a channel access procedure for load based equipment (LBE). For example, the first category LBT may be applied to a Type 2C channel access procedure. The second category LBT may be applied to Type 2A and Type 2B channel access procedures. The fourth category LBT may be applied to the Type 1 channel access procedure. In addition, the above-described LBT operation methods may be applied to a channel access procedure for frame based equipment (FBE). LBE and FBE operation methods will be described later.

“The communication node initiated or secured COT or CO (channel occupancy)” may mean “the communication node occupied the channel(s) by successful LBT operation.” "Transmitting a signal in" may mean "transmitting a signal on the channel(s) occupied by the communication node within a certain time period", where CO is the channel(s) occupied by the communication node or it may mean the transmission(s) on the channel(s) being occupied. Alternatively, CO may mean the set of channel(s) occupied by the communication node and the time interval occupied by the communication node. CO and COT may be used interchangeably, In embodiments, a node that initiated or initiated COT (eg, an initiating node) may be referred to as a “sending node” and initiates COT Alternatively, a node that transmits and receives signals in the corresponding COT without initiating may be referred to as a “receiving node.” The COT may be shared from the transmitting node to the receiving node. The receiving node performs not only the receiving operation but also the transmitting operation in the shared COT. Therefore, the sending node can perform not only the sending operation but also the receiving operation in the shared COT.

3A is a conceptual diagram illustrating a first embodiment of a communication method within the COT, and FIG. 3B is a conceptual diagram illustrating a second embodiment of a communication method within the COT.

Referring to FIG. 3A , a base station (eg, gNB) may initiate COT by performing an LBT operation. The base station may transmit a downlink transmission burst (Tx burst) at the beginning of the COT. In addition, the COT initiated by the base station may be shared with the terminal. The UE may transmit an uplink transmission burst within the shared COT. In this case, the terminal may perform an LBT operation for transmission of an uplink transmission burst. For example, the UE may perform CCA before an uplink transmission burst. Alternatively, the UE may transmit an uplink transmission burst without performing CCA. The terminal may acquire information necessary for LBT operation (eg, whether CCA is performed, LBT category, length of a sensing interval, etc.) through a predefined rule and/or a signaling procedure from the base station. The CCA operation of the terminal may be performed within the T1 period. T1 may be a time interval between an end time of a previous transmission burst (eg, a downlink transmission burst) and a start time of an uplink transmission burst.

The downlink transmission burst may be a set of consecutive downlink signals and/or channels in the time domain. The uplink transmission burst may be a set of continuous uplink signals and/or channels in the time domain. "The signals and/or channels that make up a transmission burst (eg, a downlink and/or uplink transmission burst) are said to be continuous in the time domain" means that "a gap between signal and/or channel transmissions It may mean "below the reference value". The reference value may be predefined in the technical standard. For example, the reference value may be 0. As another example, the reference value may be a value greater than 0 (eg, 16 μs).

Referring to Figure 3b, the terminal may obtain a COT by performing the LBT operation. The UE may transmit an uplink transmission burst at the beginning of the COT. In addition, the COT initiated by the terminal may be shared with the base station. The base station may transmit a downlink transmission burst within the shared COT. In this case, the base station may perform an LBT operation for transmission of a downlink transmission burst. For example, the base station may perform CCA before the downlink transmission burst. Alternatively, the base station may transmit a downlink transmission burst without performing CCA. The CCA operation of the base station may be performed within the T2 period. The base station may obtain information necessary for LBT operation (eg, whether CCA is performed, LBT category, the length of the sensing interval, etc.) through a predefined rule. T2 may be a time interval between an end time of a previous transmission burst (eg, an uplink transmission burst) and a start time of a downlink transmission burst.

The maximum occupancy time of the channel (or the maximum transmittable time of a signal) according to the CCA operation may be defined as a maximum COT (MCOT). In embodiments, the maximum occupancy time of the channel according to the CCA operation performed by the base station may be referred to as "downlink MCOT", and the maximum occupancy time of the channel according to the CCA operation performed by the terminal is "uplink MCOT" " can be referred to as Therefore, the COT started by the base station cannot exceed the downlink MCOT, and the COT started by the terminal cannot exceed the uplink MCOT. Downlink MCOT and uplink MCOT may be predefined in technical specifications according to frequency regulation, channel access priority class, and the like. The terminal may receive configuration information of the uplink MCOT from the base station. Alternatively, the downlink MCOT and the uplink MCOT may be determined by configuration information from the base station. For example, the configuration information may include information on a fixed frame period (FFP), which will be described later.

The transmitting node (or the receiving node) transmits information about the COT (eg, COT configuration information) acquired by the signaling procedure (eg, DCI signaling, uplink control information (UCI) signaling, MAC (medium access) control) may be informed to the receiving node (or the transmitting node) through control element (CE) signaling, RRC signaling, etc.). The setting information of the COT (or COT indication information) may include a start time of the COT, an end time of the COT, and/or a duration (eg, the length of the COT) of the COT. The COT setting information that the transmitting node (or the receiving node) informs the receiving node (or the transmitting node) may be different from the information about the COT actually obtained by the transmitting node. The configuration information of the COT may be dynamically or semi-statically configured (or indicated). Alternatively, the setting information of the COT may be predefined, and the predefined setting information may be shared between communication nodes in advance.

For example, the base station may inform the terminal of the configuration information of the COT started by the base station. In this case, the specific operation of the terminal may be dependent on the configuration information of the COT obtained from the base station. For example, when the configuration information of the COT is received from the base station, the terminal changes the LBT operation for uplink transmission within the COT indicated by the configuration information (eg, from the fourth category LBT to the second category LBT) can be changed), and the changed LBT operation can be performed. For another example, the PDCCH monitoring operation of the UE within the COT indicated by the base station may be different from the PDCCH monitoring operation outside the COT indicated by the base station. For another example, the CSI-RS reception and measurement operation of the UE within the COT indicated by the base station may be different from the CSI-RS reception and measurement operation outside the COT indicated by the base station. Conversely, the terminal may inform the base station of the configuration information of the COT started by the terminal. In this case, the specific operation of the base station may be dependent on the configuration information of the COT received from the terminal. For example, the transmission operation of the base station within the COT shared between the base station and the terminal may be determined based on configuration information of the shared COT.

On the other hand, a communication device (eg, a communication node, a base station, a terminal) that performs an LBT operation in an unlicensed band may be classified into an LBE and an FBE. In addition, the channel access procedure of the unlicensed band may be performed based on the LBE operation method and/or the FBE operation method. When the LBE operation method is used, the communication node may perform a sensing operation for channel access at a time desired by the communication node. That is, the sensing operation may be performed in an on-demand manner. For example, the communication node may dynamically perform a channel access operation according to traffic generation. On the other hand, when the FBE operation method is used, the communication node may perform a sensing operation for channel access at a periodically repeated time point. For example, the FFP may be periodically repeated, and a sensing operation may be performed in a specific period of each FFP (eg, an idle period within the FFP).

4 is a conceptual diagram illustrating a first embodiment of an FFP setting method.

Referring to FIG. 4 , the FFP may include a COT and an idle period. The duration of the FFP may be referred to as T _x , a COT (or CO) having a length of T _y may be disposed at the front of the FFP, and an idle section having a length of T _z may be disposed at the rear of the FFP can be Each of T _x , T _y , and T _z may be positive. The sum of T _y and T _z may be T _x . Here, COT may mean MCOT. That is, the duration of the MCOT may be T _y , and the COT actually occupied by the communication node may be shorter than T _y . The length of the idle section may occupy Z% of the FFP. For example, Z=5. A minimum value of the length of the idle period may be defined. For example, the minimum value of the length of the idle period may be 100 μs. In this case, it may be T _z =max(0.05×T _x , 100 μs). The FFP may appear periodically and repeatedly, and (20/T _x ) FFPs may be disposed within two consecutive radio frames (eg, a 20 ms interval).

A communication node (eg, a base station) may determine the FFP. Also, a communication node (eg, a base station) may change the FFP. The determined FFP or the changed FFP may last for at least a certain period of time. That is, the minimum change period of the FFP may be defined. In addition, a communication node (eg, a base station) may transmit the FFP or configuration information regarding the FFP to another communication node (eg, a terminal), and the other communication node (eg, a terminal) to the FFP or FFP An FFP may be determined based on related configuration information, and transmission and/or a channel connection operation with a communication node (eg, a base station) may be performed in a channel within the determined FFP.

When the sensing operation succeeds in the idle section before the FFP (eg, when the channel is determined to be in an idle state), the communication node may transmit a signal within the COT of the corresponding FFP. On the other hand, if the sensing operation fails in the idle section before the FFP (for example, when the channel is determined to be occupied), the communication node does not perform the channel occupation operation and/or signal transmission operation within the COT of the corresponding FFP. can't In this case, the communication node may attempt CCA for the next FFP in the idle period of the FFP.

The LBT operation performed by the FBE in the idle period or the gap period (eg, the gap period within the COT) is "LBT operation by the second category" or "LBT operation by the second category similar operation (eg, One-shot LBT)". For example, the FBE may perform an energy detection operation for a slot duration having a length of at least T μs in an idle period or a gap period, and a comparison result between the energy detection operation result and the energy detection threshold value It is possible to determine the channel state based on the T may be predefined in the technical standard. For example, T may be 9. The FBE operation method may be used when an environment in which other communication systems do not coexist (in terms of frequency regulation) is guaranteed. For example, in an NR or LTE communication system, the FBE operation method may be used in an environment in which a WiFi system and a device do not coexist. In addition, a communication node (eg, a base station, a terminal) may transmit a signal (eg, a downlink transmission burst, an uplink transmission burst) without a channel sensing operation when a specific condition is satisfied within the COT. For example, when the gap between the signal to be transmitted by the communication node and the previous transmission is less than or equal to a reference value, the communication node may transmit the signal without a channel sensing operation. That is, the channel sensing operation may be omitted.

In embodiments, the idle period may mean a period defined as an absolute time (eg, a period having a length of T _z ). Alternatively, the idle period may mean a set of symbol(s). For example, the idle period may be a set of symbol(s) overlapping with the idle period defined by absolute time. In particular, the operation of the communication node (eg, base station, terminal) related to the idle period may be based on the latter meaning.

In the FBE mode of operation, the COT may be initiated by the base station. The base station may transmit a downlink transmission burst to the terminal from the start of the COT when the LBT operation is successful in the idle section. In addition, the base station may transmit a downlink transmission burst at different times within the COT. That is, the base station and the terminal may perform discontinuous downlink transmission within one COT. The COT initiated by the base station may be shared with the terminal. In this case, the terminal may transmit uplink transmission burst(s) to the base station within the shared COT.

The base station may transmit configuration information for LBT operation to the terminal. Configuration information for LBT operation may be transmitted through higher layer signaling (eg, RRC signaling, SIB, SIB1). The configuration information for the LBT operation may include information indicating an LBT operation method (eg, an LBE operation method or an FBE operation method) performed in the terminal. The terminal may receive configuration information for LBT operation from the base station. When the FBE operation method is used, the configuration information for the LBT operation may further include information about the FFP (eg, the period of the FFP or the length of the FFP). In addition, the setting information for the LBT operation may include the arrangement position of each FFP in the time domain, the arrangement position of the COT constituting each FFP, and / or the arrangement position of the idle section constituting each FFP. Alternatively, the terminal sets the arrangement position of each FFP in the time domain, the arrangement position of the COT constituting each FFP, and/or the arrangement position of the idle section constituting each FFP to setting information for LBT operation (e.g., to the FFP information) and pre-defined rules.

Embodiments may be applied to both the LBE operation method and the FBE operation method. Alternatively, the embodiments may be applied to any one of the LBE operation method and the FBE operation method. In embodiments, “COT or CO” may mean “COT or CO based on LBE operation”. Also, in embodiments, “COT or CO” may mean “COT or CO based on FBE operation”.

On the other hand, the LBT operation may be performed in a specific frequency bundle unit. A frequency bundle may be referred to as a “channel”, “LBT subband”, “subband”, or “resource block (RB) set”. In embodiments, the LBT subband or subband may mean an RB set. In embodiments, a channel may mean an LBT subband, a subband, an RB set, and the like. Alternatively, the channel may correspond to an LBT subband, a subband, an RB set, and the like. The LBT operation may include the above-described CCA operation. Alternatively, the LBT operation may include "CCA operation + transmission operation of a signal and/or channel according to CCA operation". The bandwidth of a channel or LBT subband may vary according to spectrum regulations, frequency bands, communication systems, operators, manufacturers, and the like. For example, the bandwidth of the channel in the 5 GHz band may be 20 MHz. The communication node may perform sensing and data transmission operations in units of 20 MHz or a frequency bundle corresponding to 20 MHz.

The LBT subband may be a set of contiguous RBs. The size of the LBT subband may correspond to the bandwidth of the channel (eg, 20 MHz). The base station may set the LBT subband to the terminal. The configuration information of the LBT subband may include information about a set of RBs constituting the LBT subband (eg, the start RB, the end RB, and/or the number of RBs). One carrier and/or one bandwidth portion may include at least one LBT subband. When the carrier consists of a plurality of LBT subbands, the configuration information of each LBT subband may be signaled to the terminal.

When the carrier and/or bandwidth portion is composed of a plurality of LBT subbands, a guard band may be inserted between adjacent LBT subbands. The guard band may be disposed within the carrier. To distinguish between the guard band in the carrier and the guard band in the area outside the carrier, the guard band in the carrier may be referred to as an “intra-carrier guard band” or an “intra-cell guard band”. In embodiments, “in-carrier guard band” or “in-cell guard band” may be referred to as “guard band” for convenience. The guard band may be a set of contiguous RBs. RBs constituting the guard band may be referred to as guard RBs. If the number of LBT subband(s) constituting the carrier is L, (L-1) guard bands may be arranged in the carrier. L may be a natural number. The size of any guard band may be zero.

Figure 5 is a conceptual diagram showing a first embodiment of the LBT subband and guard band setting method.

Referring to Figure 5, one carrier may be composed of four LBT subbands. The three guard bands may be disposed between adjacent LBT subbands. In this case, L (ie, the number of LBT subbands) may be 4. The LBT subband and the guard band may be set in a carrier unit. Each LBT subband and each guard band may be composed of some CRB(s) of the continuous CRBs constituting the carrier.

The base station is information about the frequency range of each LBT subband constituting the carrier to the terminal (eg, the start CRB index, the end CRB index, and / or the number of CRBs (or, the number of RBs)) and / or of the LBT subband The number may be informed through a signaling procedure (eg, RRC signaling procedure). The base station provides the terminal with information about the frequency range of each guard band constituting the carrier (eg, the start CRB index, the end CRB index, and/or the number of CRBs (or the number of RBs)) and/or the number of guard bands. It may be informed through a signaling procedure (eg, RRC signaling procedure). The LBT subband and guard band configured for the carrier may be equally applied to the bandwidth portion belonging to the carrier. That is, the UE may consider the PRB(s) corresponding to the CRB(s) constituting each LBT subband and each guard band on the bandwidth part as the LBT subband and the guard band for the corresponding bandwidth part. Each LBT subband can be completely included in the bandwidth portion. Alternatively, each LBT subband may not be included in the bandwidth portion at all. That is, each LBT subband may not be partially included in the bandwidth portion. Alternatively, the bandwidth portion may include a portion of the LBT subband. For example, the initial downlink bandwidth portion may occupy some frequency region of the LBT subband.

The union of the RBs constituting the LBT subband(s) and the guard band(s) may be the same as the set of RBs constituting the carrier (or bandwidth portion). That is, each RB constituting the carrier (or bandwidth portion) may belong to at least one LBT subband or guard band. Simultaneously or separately, the RB sets constituting each LBT subband and each guard band may be disjoint sets. That is, each RB constituting a carrier (or bandwidth portion) may belong to only one LBT subband or only one guard band. In this case, the terminal may obtain the frequency range of the LBT subband (s) based on the configuration information about the guard band received from the base station. For example, the start RB of the first subband may be the start RB of the carrier, and the end RB of the first subband may be an RB before the start RB of the first guard band. For another example, the start RB of the last subband may be an RB after the last RB of the last guard band, and the end RB of the last subband may be the end RB of the carrier.

The guard band may be independently configured for each of the downlink and the uplink. Therefore, the LBT subband may also be configured independently for each of the downlink and uplink. The frequency range of the guard band (eg, a start CRB index, an end CRB index, and/or the number of CRBs (or the number of RBs)) may be predefined in the technical standard. If information on the frequency range of the guard band is not received from the base station, the terminal may determine the frequency range of the LBT subband (s) and the guard band (s) based on the frequency range of the guard band defined in the technical specification .

A communication node (eg, a base station, a terminal) may perform an LBT operation, and CCA (eg, an LBT operation) may occupy the successful LBT subband(s). That is, the communication node may initiate COT in the LBT subband(s) where CCA succeeded. The communication node may transmit a signal during the COT period in the occupied LBT subband(s). The base station may indicate to the terminal information about the valid LBT subband (s) and / or invalid LBT subband (s). The above-described information may be transmitted to the terminal together with the configuration information of the COT. Alternatively, the above-described information may be included in the configuration information of the COT transmitted to the terminal. The base station may determine at least a portion of the LBT subband(s) occupied by it as a valid LBT subband(s). A communication node may not transmit a signal in the guard band. Alternatively, the communication node may transmit a signal in the guard band. For example, when transmission is performed in both LBT subbands adjacent to the guard band, transmission in the guard band may be performed at least at the same time as transmission in the two LBT subbands.

Meanwhile, the uplink data channel (eg, PUSCH) may be scheduled by a dynamic grant or a configured grant. The dynamic grant may be DCI (or DCI format) including scheduling information, and the base station may transmit DCI (or DCI format) to the UE through a downlink control channel (eg, PDCCH). The configuration grant may include information for semi-static or semi-persistent configuration of scheduling, dynamic reconfiguration, etc., and the base station transmits the configuration grant to higher layer signaling (eg, RRC signaling) and/or physical layer dynamic It may be transmitted to the UE through signaling (eg, DCI or DCI format).

By receiving the configuration grant, the UE may acquire information on resource region(s) in which PUSCH can be transmitted (hereinafter, referred to as “configuration grant resource(s)”). The configuration grant resource may be periodically configured. One or a plurality of configuration grant resource(s) may be periodically repeated. When uplink traffic (eg, uplink shared channel (UL-SCH)) occurs, the UE can transmit a PUSCH in the configured grant resource without transmitting a separate scheduling request (SR) or receiving a dynamic grant. there is. Therefore, the transmission delay according to the configuration grant may be reduced compared to the transmission delay according to the dynamic grant. In addition, when the configuration grant is used, the transmission failure probability of the PUSCH due to the failure of the LBT operation may be reduced than the transmission failure probability of the PUSCH due to the failure of the LBT operation when the dynamic grant is used. A PUSCH transmitted in a configuration grant resource may be referred to as a “configuration grant PUSCH” or a “CG-PUSCH”.

A configuration method of a configuration grant resource in an NR communication system may be classified into two types. In the type 1 configuration method of the configuration grant resource, both configuration of scheduling information of PUSCH and activation of a resource (eg, configuration grant resource) may be performed by the RRC signaling procedure. In the type 2 configuration method of the configuration grant resource, the configuration of some scheduling information of the PUSCH may be performed by the RRC signaling procedure, and the configuration of the remaining scheduling information of the PUSCH and the activation of the resource (eg, the configuration grant resource) are physical It may be performed by a layer signaling procedure (eg, DCI).

[CP extension]

In unlicensed band transmission, the CP of a certain symbol (eg, OFDM symbol) may be extended. For example, the CP of a certain symbol may be extended up to the duration of the previous symbol(s), and a signal transmitted in the corresponding symbol may be transmitted in an interval including the extended CP interval. The length of the CP extension period may be referred to as a CP extension value and may be denoted by T. CP extension may be applied to a specific symbol (eg, the first symbol) among the symbol(s) constituting the physical signal and the channel. In the case of uplink, CP extension may be applied to PUCCH, PUSCH, SRS, PRACH, DM-RS, PT-RS, and the like. In the case of downlink, CP extension may be applied to PDCCH, PDSCH, CSI-RS, tracking reference signal (TRS), PRS, SS/PBCH block, DM-RS, PT-RS, and the like.

The CP extension method may be used when it is desired to set a gap with a previous transmission to a specific value. The transmitting node can set the gap with the previous transmission to a specific value (eg, 25 us, 16 us) by extending the CP of the first symbol of the signal to be transmitted, and LBT operation (eg, , second category LBT, type 2/2A/2B/2C channel access operation) can be performed, and when the LBT operation is successful, a corresponding signal can be transmitted. This method may be applied to PUCCH, PUSCH (eg, PUSCH scheduled by a dynamic grant), SRS, and the like.

The CP extension value, T, may be determined by the length of the gap period and/or timing advance (TA) of the terminal. The duration of the symbol(s) existing between the start symbol of the signal to be transmitted and the last symbol of the previous transmission may be referred to as S, and the gap duration may be referred to as G. When the previous transmission is downlink transmission, the CP extension value T may be determined by the gap duration and the TA of the UE. For example, it may be T=S-G-TA. On the other hand, when the previous transmission is the UE's own uplink transmission, T may be determined by the gap duration without depending on the TA value. For example, it may be T=S-G. The base station may configure or instruct T or information used to determine T to the terminal. The terminal may obtain information used to determine T or T from the base station. For example, information used to determine T or T may be included in DCI that triggers transmission of PUCCH, PUSCH, SRS, etc., and the base station may transmit the DCI to the terminal.

The CP extension method may be used for other purposes. For example, in the case of a configuration grant PUSCH, CP extension may be applied for the purpose of increasing spectral efficiency. In the periodic configuration grant PUSCH resource, the PUSCH may be transmitted intermittently. In this case, the base station may configure a plurality of configuration grant PUSCH resources for a plurality of terminals with respect to the same resource. That is, the PUSCH may be overloaded. In this case, if the configuration grant PUSCH start times of the plurality of terminals are aligned, the plurality of terminals perform sensing at the same time and transmit the PUSCH at the same time, so that transmission collision may occur. Therefore, in order to avoid transmission collision, a plurality of UEs may apply different CP extension values to the configured grant PUSCH transmission. When T1>T2 for CP extension values T1 and T2, a UE to which T1 is applied may have a higher channel access priority for the same configured grant PUSCH resource than a UE to which T2 is applied. In this case, the CP extension value, T, may be determined to be a value independent of the gap with the previous transmission. For example, T is 16 us, 25 us, 34 us, … may have values such as The base station may inform the terminal of T or information used to determine T through the RRC signaling procedure. The terminal may obtain information used to determine T or T from the base station. When "a plurality of configuration grant resource settings (or a plurality of configuration grant settings)" is configured in the terminal, T may be set for each configuration grant resource configuration.

The CP extension may be used in both the LBE operation method and the FBE operation method. In the case of the LBE operation method, the configuration grant PUSCH may be transmitted based on the fourth category LBT (or type 1 channel access operation). Alternatively, the terminal may receive the COT duration indicator from the base station, and when the base station acquires information on the initiated COT period, the set grant PUSCH within the corresponding COT is set to the second category LBT (or type 2A channel access operation) can be transmitted based on The terminal may determine a transmission start time of the configured grant PUSCH and a channel sensing period corresponding to the transmission start time based on the CP extension value set by the base station, and may perform the corresponding operation.

Meanwhile, in the FBE operation method, the terminal may perform an operation of a transmitting node (eg, a node initiating COT). A terminal (eg, FBE, a terminal performing an FBE operation method) succeeds in LBT operation in an idle period (eg, a sensing period, a sensing slot, a period immediately preceding the COT) for a certain channel (s) COT may be initiated, and an uplink transmission burst may be transmitted to the base station from the start time of COT. The COT initiated by the terminal may be shared with the base station. In this case, the base station may transmit a downlink transmission burst to the terminal within the shared COT.

The FFP for the case where the transmitting node is a terminal (hereinafter referred to as “uplink FFP”) may be distinguished from the FFP (hereinafter referred to as “downlink FFP”) for the case where the transmitting node is a base station. The terminal may receive information about the downlink FFP from the base station. The terminal may receive information about the uplink FFP (ie, FFP for the case where the transmitting node is the terminal itself) from the base station. The information on the uplink FFP may include at least the information (eg, period) on the downlink FFP described above. In addition, the information about the uplink FFP may include information about the time offset of the FFP. The time offset may be commonly applied to all FFPs. Also, the time offset may be an offset between a start time of a certain FFP (eg, a first FFP appearing after the reference time) and a reference time (eg, a start point of every second radio frame). The setting unit of the time offset may be Ns slot(s) or Nb symbol(s). Each of Ns and Nb may be a natural number. For example, Ns=1 and Nb=1. The above-described method of applying the time offset of the FFP may be equally applied to the downlink FFP. In addition, the information on the time offset of the downlink FFP may be included in the information on the downlink FFP and may be signaled to the terminal. When a plurality of uplink FFPs are configured in the terminal, the period and/or time offset of each uplink FFP configuration may be independently configured. Uplink FFP settings may have different periods and/or different time offsets.

In embodiments, the COT and the idle period constituting the downlink FFP may be referred to as "downlink COT" and "downlink idle period", respectively. In addition, the COT and the idle period constituting the uplink FFP may be referred to as "uplink COT" and "uplink idle period", respectively.

Information on the uplink FFP may be included in system information (eg, SIB1), and the base station may transmit the corresponding system information to the terminal. In addition, information about the uplink FFP may be transmitted to the terminal through RRC signaling (eg, terminal-specific RRC signaling, cell-specific RRC signaling). When a plurality of configuration information is received through a plurality of signaling methods (eg, SIB-1 and UE-specific RRC signaling) with respect to a certain uplink FFP, the UE is based on a predetermined priority among the plurality of configuration information Thus, any one configuration information (eg, configuration information received by UE-specific RRC signaling) may be selected, and an uplink FFP may be configured based on the selected configuration information.

When the UE succeeds in channel sensing in the idle period of a certain uplink FFP, the COT may be initiated by transmitting an uplink signal in the start period of the next uplink FFP (eg, a symbol set including the first symbol). . Therefore, the start period of the uplink FFP in which the terminal intends to initiate COT may be composed of symbol(s) capable of uplink transmission. When the slot format is configured in the terminal, the start period of the uplink FFP may be an uplink symbol and/or a flexible symbol.

In addition, the start period of the uplink FFP may be a symbol in which an SS/PBCH block, a type 0 PDCCH CSS set, etc. are not transmitted. The base station may transmit information instructing to transmit an uplink signal and/or a channel (eg, PUCCH, PUSCH, SRS, PRACH, etc.) to the terminal in the start period of the uplink FFP. The UE may receive information instructing transmission of an uplink signal and/or a channel (eg, PUCCH, PUSCH, SRS, PRACH, etc.) from the base station in the start period of the uplink FFP. That is, transmission of an uplink signal and/or a channel (eg, PUCCH, PUSCH, SRS, PRACH, etc.) in the start period of the uplink FFP may be configured or instructed by the UE. When uplink transmission is impossible in the start period of the uplink FFP in which the terminal intends to initiate the COT, the terminal may not initiate the corresponding COT. That is, the terminal may not transmit the uplink signal in the start period (eg, the start period in which transmission is impossible) of the corresponding uplink FFP. Also, the UE may not perform a channel sensing operation for the corresponding uplink FFP.

A configuration grant PUSCH resource may be configured in the start period of the uplink FFP (eg, a symbol set including the first symbol). The UE may initiate uplink COT by transmitting the PUSCH in the configured grant PUSCH resource. PUSCH transmission may be determined by the UE. Alternatively, PUSCH transmission may be configured or indicated by the base station. In this case, the UE may transmit the PUSCH on the configured grant PUSCH resource based on the configuration or instruction of the base station even when there is no uplink data or uplink control information to be transmitted through the PUSCH.

The base station may transmit information indicating whether CP extension is applied to the configured grant PUSCH resource to the terminal. The terminal may receive the corresponding information from the base station, and based on this, may check whether the CP extension is applied or not applied to the configured grant PUSCH resource. Alternatively, the configuration information of a certain “configuration grant resource configuration” configured in the terminal may include information indicating to apply CP extension to configuration grant PUSCH resources and/or information about a CP extension value, and a configuration grant PUSCH resource One of the configuration grant PUSCH resources may be disposed in a start period (eg, a symbol set including the first symbol) of the uplink FFP of the UE. In the following embodiments, methods for performing channel access and PUSCH transmission in consideration of CP extension in a configuration grant PUSCH resource disposed in the start section of an uplink FFP will be described.

6 is a conceptual diagram illustrating embodiments of a configuration grant PUSCH transmission method in consideration of CP extension.

Referring to FIG. 6 , an uplink FFP (ie, UL FFP) may be configured in the terminal, and the uplink FFP may be composed of a transmissionable period (eg, COT) and an idle period. The terminal may receive information on the configuration grant PUSCH resource for the start period (eg, a symbol set including the first symbol) of the first uplink FFP from the base station. That is, the configuration grant PUSCH resource may be configured in the start period of the first uplink FFP. CP extension may be configured in the configuration grant PUSCH (or configuration grant resource configuration corresponding to the configuration grant PUSCH).

According to the first embodiment shown in FIG. 6 , the UE may transmit the PUSCH without applying the CP extension in the configured grant PUSCH resource disposed in the start period of the first uplink FFP. The channel sensing time for the transmission of the PUSCH is immediately before the start time of the PUSCH to which the CP extension is not applied (that is, an idle period or a part of the idle period of the previous uplink FFP (eg, the sensing slot shown in FIG. 6)) can In other words, the UE may not follow the CP extension application instruction of the base station for the configuration grant PUSCH. Although the CP extension for the configuration grant resource is configured, the UE may perform the same operation as in the case where the CP extension is not configured. This operation may be referred to as (method 100).

When (Method 100) is used, the UE may transmit a PUSCH without applying CP extension to all configuration grant resources configured by configuration grant resource configuration. Alternatively, the UE may transmit the PUSCH without applying CP extension to some configuration grant resources of the configuration grant resource configuration. For example, for the same configuration grant resource configuration, the UE may transmit a PUSCH without application of CP extension in a configuration grant resource disposed in the start section of the uplink FFP, and a configuration that is not disposed in the start section of the uplink FFP PUSCH may be transmitted by applying CP extension to the grant resource. That is, the UE may ignore the CP extension configuration only for the PUSCH that initiates the COT.

According to (Method 100), when a plurality of terminals attempt to initiate COT by using a configuration grant PUSCH resource having the same start symbol, transmission collision may occur. However, transmission collisions include "a method of setting different time offsets in the uplink FFP of terminals", "a method of setting different CP extension values for terminals", "a method of setting different CP extension values for terminals", " method" and the like.

As a method different from (Method 100), when at least one configuration grant resource is disposed in the start section of the uplink FFP for a certain configuration grant configuration, CP extension may not be configured for the corresponding configuration grant configuration. That is, when it is configured to apply CP extension to a certain configuration grant configuration, the configuration grant resource allocated by the corresponding configuration grant configuration may not be arranged in the start section of the uplink FFP. Alternatively, the actual transmission period of the configuration grant resource including the CP extension period may belong to the transmittable period (eg, COT) of the uplink FFP. Alternatively, with respect to a certain configuration grant configuration, CP extension may be applied only to some configuration grant resources. "Information on configuration grant resource(s) to which CP extension is applied" and/or "information about configuration grant resource(s) to which CP extension is not applied" may be included in the configuration grant configuration information, and the corresponding configuration grant configuration The information may be transmitted to the terminal. For example, the CP extension may be applied to at least one configuration grant resource(s) within one configuration grant period, and the configuration grant resource(s) to which the CP extension is applied may appear repeatedly every configuration grant period. Alternatively, a separate period for “configuration grant resource(s) to which CP extension is applied” and/or “configuration grant resource(s) to which CP extension is not applied” may be configured. The separate period may be set independently of the period of the uplink FFP configured in the terminal. Alternatively, the separate period may be determined by the period of the uplink FFP configured in the terminal.

Meanwhile, uplink COT may be initiated not only by the configured grant PUSCH but also by dynamically scheduled uplink transmission (eg, dynamic grant PUSCH, periodic SRS, PUCCH by dynamic grant, etc.). The CP extension for the above-described transmission may be indicated by a dynamic grant (eg, DCI, random access response (RAR) uplink grant), and the CP extension value may be included in the dynamic grant. When the dynamic grant indicates to perform the transmission in the start section of the uplink FFP (eg, a symbol set including the first symbol), the UE does not receive an indication or configuration of CP extension for the transmission can be expected Alternatively, the UE may expect that the CP extension value indicated for the transmission is 0. Alternatively, even when a CP extension (eg, a CP extension greater than 0) is indicated or configured for the corresponding transmission, the UE may ignore the instruction or configuration of the CP extension. That is, the UE may not apply the CP extension.

According to the second embodiment shown in FIG. 6 , the UE may transmit the PUSCH by applying the CP extension to the configured grant PUSCH resource disposed in the start period of the first uplink FFP. In this case, the channel sensing period (eg, the sensing slot shown in FIG. 6 ) for PUSCH transmission may be advanced by the length of the CP extension period. This operation may be referred to as (method 110). According to (Method 110), the configuration grant PUSCH may be transmitted in the uplink idle section. (Method 110) can be limitedly used when the terminal can perform uplink transmission in the previous uplink idle section (eg, when the terminal does not initiate COT in the last uplink FFP).

In (Method 110), the sum of the CP extension value and the length (eg, 9 us) of the channel sensing period may not be longer than the length of the uplink idle period. That is, the CP extension value may be set to a value that does not exceed the difference between the length of the uplink idle section and the length of the channel sensing section. On the other hand, when the sum of the CP extension value and the length of the channel sensing section is greater than the length of the uplink idle section, the adjusted sensing section may deviate at least partially from the uplink idle section. In this case, the terminal may perform a sensing operation in a section outside the uplink idle section. The above-described operations may violate the frequency regulation condition of the FBE operation method. In order to prevent the channel sensing period from leaving the uplink idle period, the CP extension value may be adjusted. For example, the smaller of "the length of the uplink idle section - the length of the channel sensing section" and the "CP extension value set by the base station" is a CP extension value for uplink transmission arranged in the start section of the uplink FFP. can be used as

As another method for solving the above-described problem, a method of adjusting the position of the uplink FFP of the terminal in consideration of the CP extension value may be used. According to the third embodiment shown in FIG. 6 , the terminal and/or the base station may advance the start time of the first uplink FFP (or the entire period of the period) by the CP extension value. The start time of a certain period of the uplink FFP (or the entire period of the period) may be determined by a CP extension value and/or a time offset. Also, the start time of another period of the uplink FFP (or the entire period of the period) may be advanced by the CP extension value. For example, all periods of the uplink FFP may be shifted by the same value in consideration of the CP extension value. “A certain FFP is temporally shifted” may mean “a transmittable period (eg, COT) and an idle period constituting the FFP are temporally shifted”. The position of the channel sensing period (eg, sensing slot) for the UE to initiate COT may also be shifted by the CP extension value. This operation may be referred to as (method 120).

In (Method 120), the CP extension value may be a value for CP extension applied to the configuration grant PUSCH. Alternatively, the CP extension value may be a CP extension value applied to other uplink signals and/or channels. Meanwhile, a plurality of uplink transmissions may be allocated (or configured) in the start period of the uplink FFP, and it may be configured to apply CP extension to each of the plurality of uplink transmissions. In this way, when a plurality of CP extension values are set for transmission of the start period of the uplink FFP, the position of the uplink FFP may be shifted by the largest value among the plurality of CP extension values. Alternatively, the CP extension value (or a value corresponding to the CP extension value) may be included in the configuration information of the uplink FFP, and the configuration information may be transmitted to the terminal. Alternatively, the CP extension value may be included in the time offset information of the uplink FFP. For example, the time offset of the uplink FFP may have a sub-symbol unit value rather than a symbol unit value, and a symbol offset from a reference view and a CP extension value (or a CP extension value) The sum or difference of the corresponding values) can be expressed by a time offset.

When a plurality of uplink FFPs (eg, uplink FFP settings having different periods and/or time offsets) are configured in the terminal, the above-described methods may be collectively applied to all uplink FFP settings. there is. Alternatively, when a plurality of uplink FFPs (eg, uplink FFP configurations having different periods and/or time offsets) are configured in the terminal, the above-described methods are independently applied to each uplink FFP configuration. can

CP extension for dynamically scheduled uplink transmission (eg, dynamic grant PUSCH, periodic SRS, dynamic grant PUCCH, etc.) may be indicated by DCI indicating the corresponding transmission. According to (Method 120), when the uplink COT is initiated by the transmission, that is, when the transmission is placed in the start section of the uplink FFP, the terminal instead of the CP extension indicated by DCI (method 120) 120) may be applied to the transmission. That is, the CP extension operation indicated by DCI may be overridden by the CP extension operation according to (Method 120) described above. In addition, the above-described method may be applied for other uplink transmission (eg, PUCCH, periodic SRS, semi-persistent SRS, PRACH, etc.) in which transmission resources are semi-statically configured in addition to the configured grant PUSCH.

The UE may apply TA for uplink transmission. That is, the terminal may advance the uplink transmission time by TA from the downlink reference time. This operation may be equally applied to uplink transmission initiating uplink COT. Accordingly, the UE may start uplink transmission for initiating COT at a time earlier than the start time of the uplink FFP (eg, the start time of the first symbol). Alternatively, the uplink FFP (eg, each cycle of the uplink FFP) may be advanced by the TA of the UE. The UE may start uplink transmission for initiating COT at the start time of the uplink FFP to which the TA is applied. When (Method 120) is used, the position of the uplink FFP (eg, each period of the uplink FFP) may be adjusted by the TA and CP extension values of the terminal. For example, each period of the uplink FFP may be advanced by the sum of the TA and CP extension values of the terminal.

[LBT type]

When the FBE operation method is used, a communication node (eg, a base station and/or a terminal) may or may not perform an LBT operation when trying to transmit a signal. Whether to perform the LBT operation may be determined by the gap between the signal to be transmitted and the previous transmission. For example, each of the base station and the terminal may transmit a signal without performing a sensing operation when the time difference between the start time of the signal to be transmitted and the end time of the previous transmission is equal to or less than a reference value. This operation may correspond to the first category LBT, type 2C channel connection operation, and the like. When the above-described time gap exceeds the reference value, each of the base station and the terminal may perform a sensing operation to transmit a signal. This operation may correspond to a one-shot LBT, a second category LBT, a type 2/2A/2B channel connection operation, and the like. For example, the reference value may be 16 us. When the signal to be transmitted is a signal initiating COT (eg, a signal including the first symbol of COT), each of the base station and the terminal may perform a sensing operation to transmit the signal. Hereinafter, "LBT type" may mean "whether or not channel sensing is performed".

When uplink transmission is dynamically scheduled in the terminal, the LBT type for uplink transmission may be indicated to the terminal through a dynamic grant (eg, DCI, RAR uplink grant). In this case, the terminal can determine the LBT operation for uplink transmission (eg, whether to perform channel sensing) based on the LBT type indicated by the base station regardless of the gap size between the uplink transmission and the previous transmission. . On the other hand, when the uplink transmission is semi-statically configured in the terminal, it may be difficult to dynamically indicate the LBT type for the corresponding transmission to the terminal. For example, the UE may transmit the PUSCH in a configuration grant PUSCH resource configured by the base station. When the PUSCH is a signal for initiating uplink COT (eg, a signal transmitted in the start period of the uplink FFP), the UE may perform an LBT (eg, one-shot LBT) operation immediately before transmission of the PUSCH. . However, if the PUSCH is not a signal for initiating uplink COT (eg, a signal that does not include the first symbol of the uplink FFP), it may be difficult for the UE to determine whether there is a previous transmission of the PUSCH, Accordingly, it may be difficult to accurately determine the gap with the previous transmission.

In the proposed method, with respect to the first uplink transmission to be transmitted, the terminal itself has another transmission (eg, the first downlink transmission or the second uplink transmission) before the first uplink transmission, and , when the "gap between the first uplink transmission and the first downlink transmission" or the "gap between the first uplink transmission and the second uplink transmission" is less than or equal to the reference value, the terminal performs the first uplink transmission without performing a sensing operation can be done "When it can be clearly seen that there is a third transmission (eg, a downlink transmission transmitted by a base station, an uplink transmission transmitted by another terminal) from another communication node before the first uplink transmission" Alternatively, in "when it can be assumed that the third transmission exists," the terminal may perform the first uplink transmission without performing a sensing operation if the gap between the first uplink transmission and the third transmission is equal to or less than the reference value. The terminal may perform a sensing operation for first uplink transmission (eg, one-shot LBT) for the remaining cases except for at least one of the above-described cases, and if the sensing operation is successful, the first uplink Link transmission can be performed. For example, "when the existence of the third transmission cannot be clearly known before the first uplink transmission" or "when it cannot be assumed that the third transmission exists", the terminal performs the first uplink transmission An LBT operation may be performed. "When it can be clearly seen that other transmissions (eg, first downlink transmission, second uplink transmission, third transmission) exist before first uplink transmission" or "Assume that other transmissions exist If possible", the terminal may perform the LBT operation for the first uplink transmission if the gap between the first uplink transmission and the other transmission is equal to or greater than the reference value.

Alternatively, the terminal may receive configuration information regarding the LBT type (eg, whether or not LBT operation is performed) for the configuration grant PUSCH from the base station, and based on the configuration information, the LBT operation for the configuration grant PUSCH transmission can be done When a plurality of configuration grant resource settings can be configured in the terminal, the configuration information regarding the LBT type may be configured for each configuration grant resource configuration. Configuration information about the LBT type may be transmitted to the terminal through the RRC signaling procedure. When the LBT type for a certain configuration grant resource configuration is set in the terminal as the first category LBT (or type 2C channel access operation, an operation not performing channel sensing), the terminal allows the base station to transmit and transfer the configuration grant PUSCH of the terminal It can be regarded as always ensuring that the gap with transmission is equal to or less than the reference value, and the configuration grant PUSCH can be transmitted without performing a sensing operation. Simultaneously or separately, even if the LBT type for a certain set grant resource setting is set in the terminal as the second category LBT (or one-shot LBT, type 2/2A/2B channel access operation, channel sensing operation), The UE may transmit the configuration grant PUSCH without performing a sensing operation if it is obvious or can be assumed that the gap between the configuration grant PUSCH transmission and the previous transmission is less than or equal to the reference value. The above-described operation may be applied when the configuration grant PUSCH is not a PUSCH that initiates uplink COT. Mention of the configuration grant PUSCH in the above-described embodiments is only one example, and the above-described method includes uplink transmission other than the configuration grant PUSCH (eg, uplink transmission in which transmission resources are semi-fixedly configured, periodic PUCCH, Periodic/semi-permanent SRS, PRACH, etc.) can also be applied.

The above-described method may be applied identically or similarly to the case of repeated type B transmission of PUSCH. For repeated type B PUSCH transmission, the UE may determine an invalid symbol that cannot be used for PUSCH transmission. A symbol configured as a downlink symbol by a semi-static slot format configuration, a symbol in which an SS/PBCH block is transmitted, etc. may be regarded as an invalid symbol. In addition, N consecutive symbol(s) after the consecutive symbol(s) set in the downlink by the semi-static slot format configuration may be regarded as invalid symbols by the configuration of the base station. N consecutive symbol(s) may be a section for securing a time required for switching from downlink to uplink. N may be set in the terminal by the base station. N may be a natural number. The set of invalid symbols may be explicitly set in the terminal from the base station. In the FBE operation method, a symbol overlapping the idle period may be regarded as an invalid symbol. The UE may consider symbols that are not considered invalid symbols as valid symbols that can be used for PUSCH transmission.

When any nominal PUSCH instance allocated to the UE includes invalid symbol(s), the nominal PUSCH instance may be converted into one or more actual PUSCH(s). A certain nominal PUSCH instance may be one PUSCH instance constituting repeated PUSCH transmission. Each of the actual PUSCH instances may consist of different consecutive valid symbol(s) within the nominal PUSCH instance interval. In an embodiment, a nominal PUSCH instance may be allocated to four consecutive symbols having indices 0 to 3, and a symbol having index 1 among the four consecutive symbols may be determined as an invalid symbol. In this case, a nominal PUSCH instance may be converted into two real PUSCH instances. A first real PUSCH instance may be allocated to a symbol with index 0, and a second real PUSCH instance may be allocated to two consecutive symbols with indexes 2 to 3. When the nominal PUSCH instance is split into actual PUSCH instance(s), the UE may transmit each of the actual PUSCH instance(s) instead of the nominal PUSCH instance. Each of the actual PUSCH instance(s) may be included in one slot. When a nominal PUSCH instance is allocated over a plurality of slots, the nominal PUSCH instance may be divided based on a boundary of the plurality of slots and converted into one or more actual PUSCH instances. An actual PUSCH instance having a duration less than or equal to the reference value may be dropped. For example, the reference value may be one symbol. In this case, in the above-described embodiment, the first real PUSCH instance may be dropped, and only the second real PUSCH instance may be transmitted.

Here, the PUSCH instance may mean each PUSCH constituting repeated PUSCH transmission (eg, repeated type A or type B PUSCH transmission). When a plurality of PUSCHs are allocated through one scheduling (eg, through one DCI), a PUSCH instance may mean each PUSCH. That is, a PUSCH instance may mean one independent PUSCH transmission. Each PUSCH instance may include a DM-RS. Different PUSCH instances (eg, different PUSCH instances scheduled through the same DCI) may correspond to the same transport block (TB). Alternatively, different PUSCH instances (eg, different PUSCH instances scheduled through the same DCI) may correspond to different TBs.

In type B PUSCH repeated transmission, the UE may determine the LBT type for each actual PUSCH instance, and may perform an operation according to the determined LBT type. The LBT type for each actual PUSCH instance may be determined based on the above-described method. For example, depending on whether a gap between a certain actual PUSCH instance and previous transmission is less than or equal to a reference value, the UE may determine whether to perform a sensing operation, "by performing a sensing operation" or "without performing a sensing operation" for an actual PUSCH You can send an instance. When the actual PUSCH instance includes the first symbol of the nominal PUSCH instance, the LBT type for the actual PUSCH instance may be determined by other criteria. For example, if the nominal PUSCH instance is a PUSCH dynamically scheduled by DCI, the LBT type of the actual PUSCH instance including the first symbol of the nominal PUSCH instance is information indicated by DCI (eg, the It may be determined based on information about the LBT type for the nominal PUSCH instance).

Meanwhile, in the FBE operation method, the terminal may receive scheduling information or configuration information of continuous uplink transmissions from the base station. The terminal may perform an LBT operation for the first uplink transmission (eg, the most advanced uplink transmission) constituting successive uplink transmissions, and performs the first uplink transmission when the LBT operation fails may not In this case, the terminal may perform a predefined sensing operation for uplink transmission(s) after the first uplink transmission. For example, the terminal performs the second category LBT operation (or one-shot LBT, type 2/2A/2B channel access operation, channel sensing operation) for uplink transmission(s) after the first uplink transmission can be done The UE may consider that there is no transmission by another communication node within a time interval occupied by successive uplink transmissions.

[Frequency Hopping]

A plurality of methods may be considered for frequency domain resource allocation of PUSCH. In the embodiments below, RB may mean PRB, and PRB may correspond to CRB one-to-one. Frequency domain resources of the PUSCH may be allocated in units of resource block groups (RBGs), and whether each RBG is allocated may be indicated or configured to the UE in the form of a bitmap. The length of the bitmap may correspond to the number of RBGs. One RBG may consist of consecutive RB(s), and the number of RBs per RBG may be predefined in the technical standard. Alternatively, the number of RBs per RBG may be configured or indicated to the UE.

A PUSCH may be mapped to one or more consecutive RB(s). The starting RB and the number of RBs for consecutive RB(s) may be configured or indicated to the UE. The starting RB and the number of RBs may be substituted with a resource indicator value (RIV). The base station may inform the terminal of the RIV. The UE may receive the RIV from the base station and may find out the RB(s) to which the PUSCH is mapped based on the RIV.

On the other hand, in unlicensed band communication, an occupied channel bandwidth (OCB) requirement may exist. In this case, the transmitting node must occupy more than a certain percentage of the nominal channel bandwidth when transmitting the signal. To satisfy this, an interlace-based resource allocation scheme may be used for allocating a frequency domain resource of a PUSCH.

7 is a conceptual diagram illustrating a first embodiment of a method for allocating resources in an interlace-based PUSCH frequency domain.

Referring to FIG. 7 , the bandwidth portion may be set to 52 consecutive PRBs corresponding to CRBs #12 to #63. One interlace may be composed of PRBs corresponding to equally spaced CRBs. For a certain subcarrier interval (eg, 15 kHz), one interlace may consist of PRBs corresponding to every tenth CRB. In this case, the interval between CRBs may be expressed as “M=10”. When M=10, a total of 10 different interlaces may be defined. In the embodiment shown in FIG. 7 , interlaces #0 are CRBs #0, #10, #20, #30, ... may be composed of PRBs corresponding to (ie, PRBs #8, #18, #28, #38, and #48), and interlace #2 is CRB #2, #12, #22, #32, ... It may be composed of PRBs corresponding to (ie, PRBs #0, #10, #20, #30, #40, and #50). In this way, the position of each interlace may be determined based on the point A. According to the bandwidth portion or the size of the LBT subband, the number of PRBs included in some interlaces may be one more or less.

PUSCH may be allocated to one or a plurality of LBT subband(s) (or subband(s), RB set(s), channel(s)) within one bandwidth portion. When PUSCH is allocated to a plurality of LBT subbands, one interlace may be composed of RBs belonging to a plurality of LBT subbands, and RBs belonging to the plurality of LBT subbands correspond to equally spaced CRBs. can be The base station may configure or indicate to the terminal one or a plurality of interlaces (or a number and an index of the plurality of interlaces) as frequency domain resource allocation information of the PUSCH. In addition, the base station may set or indicate together the LBT subband (s) (or the number and index of the LBT subband (s)) to which the interlace (s) is mapped to the terminal. In the embodiment shown in FIG. 7 , the base station may configure or instruct the terminal to set interlace #0 or #2, and “5 PRBs corresponding to interlace #0” or “6 PRBs corresponding to interlace #2” PUSCH can be transmitted in Alternatively, the base station may configure or instruct interlaces #0 and #2 to the UE, and may transmit PUSCH in 11 PRBs corresponding to interlaces #0 and #2. The embodiment shown in FIG. 7 may be a case in which the bandwidth portion consists of one LBT subband, and information about the LBT subband(s) may not be separately transmitted to the terminal.

8 is a conceptual diagram illustrating a second embodiment of a method for allocating resources in an interlace-based PUSCH frequency domain.

Referring to Figure 8, the bandwidth portion consisting of two LBT subbands may be set in the terminal. The bandwidth portion may consist of 102 consecutive PRBs, and each LBT subband may consist of 51 consecutive PRBs. The bandwidth part may be an uplink band part, and may be activated in the terminal. The terminal according to the LBT performance result, the first LBT subband (hereinafter referred to as "first subband combination"), the second LBT subband (hereinafter referred to as "second subband combination"), or the first and first 2 LBT subbands (hereinafter referred to as "third subband combination") may be occupied, and PUSCH may be transmitted in the corresponding subband combination.

The PUSCH may be a configuration grant PUSCH. In this case, the base station may configure any one configuration grant resource in the terminal, and the configuration grant resource configuration may include frequency domain resource allocation information. According to the embodiment shown in FIG. 8, the frequency domain resource allocation information is an interlace to which the PUSCH is allocated (eg, interlace #0) and an LBT subband combination (eg, a first LBT subband combination, a second LBT subband combination, or information about the third subband combination). The UE may obtain frequency domain resource allocation information from the base station, and may find out PRB allocation information for configuration grant PUSCH transmission in each subband combination based on the frequency domain resource allocation information. The UE may transmit the PUSCH by using some or all of the frequency domain resources of the allocated configuration grant PUSCH. That is, the UE may transmit the PUSCH in “interlace #0 of the first subband”, “interlace #0 of the second subband”, or “interlace #0 of the first subband and the second subband”. The size of the TB transmitted through the PUSCH may be determined by "a combination of subbands to which PUSCH is mapped" or "a combination of subbands to which PUSCH is actually transmitted". That is, the size of the TB may vary according to "a combination of subbands to which PUSCH is mapped" or "a combination of subbands to which PUSCH is actually transmitted".

Frequency hopping may be applied to an interlace-based PUSCH resource allocation scheme. 9a is a conceptual diagram illustrating a first embodiment of a PUSCH frequency hopping method in units of LBT subbands, FIG. 9b is a conceptual diagram illustrating a second embodiment of a method of PUSCH frequency hopping in units of LBT subbands, and FIG. 9c is an LBT It is a conceptual diagram illustrating a third embodiment of a PUSCH frequency hopping method in units of subbands.

9a to 9c, the bandwidth portion set in the terminal may include a plurality of LBT subbands (eg, the first LBT subband and the second LBT subband). PUSCH may be transmitted in the first and second LBT subbands. The PUSCH may be transmitted through at least one interlace.

In this case, frequency hopping may be applied to the PUSCH, and a plurality of frequency hops may occupy different frequency resources. Each frequency hop of the PUSCH may be transmitted at different times. According to an embodiment, each frequency hop of the PUSCH may be mapped to one or more interlaces in one or more LBT subbands. According to the first embodiment of Figure 9a and the second embodiment of Figure 9b, the PUSCH (or each frequency hop of the PUSCH) may be mapped to the first LBT subband in the T1 interval, the second LBT subband in the T2 interval can be mapped to According to the third embodiment of FIG. 9c, the PUSCH (or each frequency hop of the PUSCH) may be mapped to the first LBT subband in the T1 period and the T2 period, and to the first and second LBT subbands in the T3 period. can be mapped. Here, each section of T1 to T6 may correspond to the duration occupied by each frequency hop of the PUSCH, and may consist of one or more symbol(s). In this case, according to the first embodiment of FIG. 9A , the PUSCH may be mapped to the same interlace(s) (eg, interlace #0) for all frequency hops. On the other hand, according to the second embodiment of FIG. 9B and the third embodiment of FIG. 9C , the interlace(s) occupied by each frequency hop may be independently set or indicated. For example, in the second embodiment of FIG. 9B and the third embodiment of FIG. 9C , the interlace(s) occupied by each frequency hop may be the same. Alternatively, in the second embodiment of FIG. 9B and the third embodiment of FIG. 9C , the interlace(s) occupied by each frequency hop may be different from each other.

The frequency hopping pattern may be repeated periodically. In the first embodiment of FIG. 9A and the second embodiment of FIG. 9B , the frequency hopping pattern of “intervals T1 and T2” may be repeated in “intervals T3 and T4”, and “intervals T1 and T2” and “T3 and T4 period" may belong to different PUSCH transmission periods (eg, a period of a configuration grant resource, a period of a frequency hopping pattern, etc.). In the third embodiment of FIG. 9C , the frequency hopping pattern of the “interval T1 to T3” may be repeated in the “interval T4 to T6”, and the “interval T1 to T3” and the “interval T4 to T6” are different PUSCH transmissions can be part of a cycle.

The base station sets the frequency hopping pattern configuration information (eg, the index of the LBT subband (s) corresponding to each frequency hop (or each interval) and / or the index of the interlace (s), the number of frequency hops, each frequency hop duration, etc.) may be transmitted to the terminal. The terminal may check the frequency hopping pattern based on the configuration information received from the base station. In the case of the dynamic grant PUSCH, the UE may receive the configuration information of the frequency hopping pattern in advance before receiving the scheduling DCI. At this time, the candidate LBT subband(s) to which the PUSCH can hop may be "all LBT subband(s)" or "some subband(s) of all LBT subband(s)" constituting the bandwidth part. In the case of the configuration grant PUSCH, the candidate LBT subband(s) to which the PUSCH is hopable may be included in the configuration grant resource configuration information (eg, frequency domain resource allocation information) and configured in the terminal.

Each frequency hop of the PUSCH may be mapped to different slots. This method may be referred to as inter-slot frequency hopping. In this case, each of the sections T1 to T6 in the above-described embodiment may belong to different slots. Alternatively, a plurality of frequency hops may be mapped in the same slot. This method may be referred to as intra-slot frequency hopping. In this case, a plurality of sections of at least some of sections T1 to T6 in the above-described embodiment may belong to the same slot.

The LBT subband-based frequency hopping method can be equally applied to the above-described RBG-based resource allocation and RIV-based resource allocation as well as interlace-based resource allocation. That is, the terminal may determine the LBT subband(s) and RBG(s) (or PRB(s)) to which each frequency hop of the PUSCH is mapped based on the frequency hopping pattern set by the base station, and the PUSCH on the resource can be sent. The above-described frequency hopping method may be equally or similarly applied to PUCCH transmission.

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

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

Although it has been described with reference to the above embodiments, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. will be able

Claims (1)

A method of operating a terminal in a communication system, comprising:
receiving first configuration information of a plurality of fixed frame periods (FFPs) for channel access of the terminal from a base station;
Receiving second configuration information of a configured grant (CG) physical uplink shared channel (PUSCH) including a first symbol of a first FFP among the plurality of FFPs indicated by the first configuration information from the base station;
checking first information indicating whether to apply a cyclic prefix (CP) extension included in the second configuration information;
initiating a channel occupancy time (COT) in the first FFP when the first information indicates the CP extension; and
Transmitting the CG PUSCH to which the CP extension is applied in the COT, the operating method of the terminal.

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