KR20200105406A - Method and apparatus for transmitting and receiving control information in communication system supporting unlicensed band - Google Patents

Abstract

Disclosed is a method and apparatus for transmitting and receiving control information in a communication system supporting an unlicensed band. The operating method of the terminal includes receiving first setting information of CORESET and second setting information of a search space related to the CORESET from a base station, a third indicating the CORESET and one or more sets of PDCCH monitoring resources related to the search space. Receiving configuration information from the base station, and performing a PDCCH monitoring operation on the one or more PDCCH monitoring resource sets. Therefore, the performance of the communication system can be improved.

Description

Method and apparatus for transmitting and receiving control information in a communication system supporting unlicensed bands {METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING CONTROL INFORMATION IN COMMUNICATION SYSTEM SUPPORTING UNLICENSED BAND}

The present invention relates to a technology for transmitting and receiving control information in a communication system, and more particularly, to a technology for transmitting and receiving control information for channel access and occupation in a communication system supporting an unlicensed band.

In order to process rapidly increasing radio data, a frequency band higher than the frequency band of LTE (long term evolution) (or LTE-A) (eg, a frequency band of 6 GHz or less) (eg, a frequency band of 6 GHz or higher) A communication system using (for example, a new radio (NR) communication system) is being considered. The NR communication system can support not only a frequency band of 6 GHz or less but also a frequency band of 6 GHz or more, and can support various communication services and scenarios compared to the LTE communication system. For example, the usage scenario of the NR communication system may include enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), and Massive Machine Type Communication (mMTC). Communication technologies are needed to meet the requirements of eMBB, URLLC, and mMTC.

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

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

In order to achieve the above object, a method of operating a terminal according to a first embodiment of the present invention includes receiving first setting information of CORESET and second setting information of a search space related to the CORESET from a base station, the CORESET and the Receiving from the base station third configuration information indicating one or more PDCCH monitoring resource sets related to the search space, and performing a PDCCH monitoring operation on the one or more PDCCH monitoring resource sets, the one or more PDCCH Each of the monitoring resource sets is located in each RB set set in the unlicensed band.

Here, among the parameters included in the first configuration information and the second configuration information, parameters other than a parameter indicating a frequency domain resource may be shared for the one or more PDCCH monitoring resource sets.

Here, the remaining parameters are information indicating the duration of the CORESET, information indicating a CCE-REG mapping type, information indicating whether to apply interleaving in a CCE-REG mapping operation, information indicating the size of a REG bundle, an interleaving rule It may include at least one of information, shift index, precoder unit information, TCI status information, information indicating whether a field indicating TCI status exists in DCI, and scrambling ID of the PDCCH DM-RS.

Here, the third setting information may be a bitmap, and each bit included in the bitmap may indicate whether a PDCCH monitoring resource set is set in the RB set.

Here, the size of the bitmap may correspond to the number of RB sets set in one bandwidth portion.

Here, each of the one or more PDCCH monitoring resource sets may include one or more RBs, and the one or more PDCCH monitoring resource sets may be disposed on a frequency domain without overlap, and the one or more PDCCH monitoring resource sets belong The above RB sets may be located within one bandwidth portion.

Here, the CORESET may be a CORESET rather than a CORESET set through a PBCH.

Here, the operating method of the terminal may further include receiving a PDCCH from at least one of the one or more PDCCH monitoring resource sets, and the at least one PDCCH monitoring resource set in which the PDCCH is received is performed by the base station. It may be located in RB sets for which the LBT operation is successful.

One or more RB sets to which the one or more PDCCH monitoring resource sets indicated by the third configuration information belong may be an RB set in which the LBT operation performed by the base station is successful.

In order to achieve the above object, a method of operating a base station according to a second embodiment of the present invention includes transmitting first setting information of CORESET and second setting information of a search space related to the CORESET to a terminal, the CORESET and the Transmitting third configuration information indicating one or more PDCCH monitoring resource sets related to the search space to the terminal, and transmitting a PDCCH to the terminal through at least one of the one or more PDCCH monitoring resource sets, , Each of the one or more PDCCH monitoring resource sets is located in each RB set set in the unlicensed band.

Here, among the parameters included in the first configuration information and the second configuration information, parameters other than a parameter indicating a frequency domain resource may be shared for the one or more PDCCH monitoring resource sets.

Here, the remaining parameters are information indicating the duration of the CORESET, information indicating a CCE-REG mapping type, information indicating whether to apply interleaving in a CCE-REG mapping operation, information indicating the size of a REG bundle, an interleaving rule It may include at least one of information, shift index, precoder unit information, TCI status information, information indicating whether a field indicating TCI status exists in DCI, and scrambling ID of the PDCCH DM-RS.

Here, the third setting information may be a bitmap, and each bit included in the bitmap may indicate whether a PDCCH monitoring resource set is set in the RB set.

Here, each of the one or more PDCCH monitoring resource sets may include one or more RBs, and the one or more PDCCH monitoring resource sets may be disposed on a frequency domain without overlap, and the one or more PDCCH monitoring resource sets belong The above RB sets may be located within one bandwidth portion.

Here, the CORESET may be a CORESET rather than a CORESET set through a PBCH.

Here, at least one PDCCH monitoring resource set through which the PDCCH is transmitted may be located within RB sets in which a listen before talk (LBT) operation performed by the base station is successful.

The terminal according to the third embodiment of the present invention for achieving the above object includes a processor, a memory in electronic communication with the processor, and instructions stored in the memory, and when the instructions are executed by the processor, The commands are a first in which the terminal receives first setting information of CORESET and second setting information of a search space associated with the CORESET) from a base station, and indicates at least one PDCCH monitoring resource set associated with the CORESET and the search space. 3 Receives configuration information from the base station, and operates to cause a PDCCH monitoring operation to be performed on the one or more PDCCH monitoring resource sets, and each of the one or more PDCCH monitoring resource sets is within each RB set set in the unlicensed band. Located.

Here, among the parameters included in the first configuration information and the second configuration information, parameters other than a parameter indicating a frequency domain resource may be shared for the one or more PDCCH monitoring resource sets.

Here, the third setting information may be a bitmap, and each bit included in the bitmap may indicate whether a PDCCH monitoring resource set is set in the RB set.

Here, each of the one or more PDCCH monitoring resource sets may include one or more RBs, and the one or more PDCCH monitoring resource sets may be disposed on a frequency domain without overlap, and the one or more PDCCH monitoring resource sets belong The above RB sets may be located within one bandwidth portion.

Here, the CORESET may be a CORESET rather than a CORESET set through a PBCH.

According to the present invention, the base station is a bitmap indicating a listen before talk (LBT) subband(s) (e.g., resource block (RB) set(s)) in which a physical downlink control channel (PDCCH) monitoring occasion is set (bitmap) can be transmitted to the terminal. The terminal may receive a bitmap from the base station, and may check the LBT subband(s) in which the PDCCH monitoring occasion is set based on the bitmap. Signaling overhead can be reduced by using a bitmap in a signaling procedure between the base station and the terminal.

In addition, the PDCCH monitoring operation may be dynamically switched within the channel occupancy time (COT) initiated by the base station. Accordingly, the degree of freedom of arrangement of the UL (uplink) transmission burst period may increase. In addition, the base station may change (eg, expand or contract) a transmission bandwidth by performing an LBT operation within the COT. Therefore, the use efficiency of spectrum can be improved, and transmission performance can be improved. That is, the performance of the communication system can be improved.

1 is a conceptual diagram showing a first embodiment of a communication system.
2 is a block diagram showing a first embodiment of a communication node constituting a communication system.
3A is a conceptual diagram showing a first embodiment of a bandwidth portion in a communication system.
3B is a conceptual diagram showing a second embodiment of a bandwidth portion in a communication system.
3C is a conceptual diagram showing a third embodiment of a bandwidth portion in a communication system.
4A is a conceptual diagram showing a first embodiment of a communication method within a COT.
4B is a conceptual diagram showing a second embodiment of a communication method within a COT.
5 is a conceptual diagram illustrating a first embodiment of a bandwidth portion set asymmetrically in a time division duplex (TDD)-based communication system.
6 is a conceptual diagram illustrating a first embodiment of a method for obtaining a COT and a method for transmitting a signal in a bandwidth portion including a plurality of LBT subbands.
7A is a conceptual diagram illustrating a second embodiment of a method for obtaining a COT and a method for transmitting a signal in a bandwidth portion including a plurality of LBT subbands.
7B is a conceptual diagram illustrating a third embodiment of a method for obtaining a COT and a method for transmitting a signal in a bandwidth portion including a plurality of LBT subbands.
8 is a conceptual diagram showing a first embodiment of a method for repeatedly transmitting COT setting information.
9A is a conceptual diagram illustrating a first embodiment of a method for mapping PDCCH and PDCCH DM-RS resources.
9B is a conceptual diagram illustrating a second embodiment of a method for mapping PDCCH and PDCCH DM-RS resources.
10 is a conceptual diagram illustrating a first embodiment of a method for transmitting a PUSCH in a configuration grant resource overlapping with a COT.
11 is a conceptual diagram illustrating a second embodiment of a method of transmitting a PUSCH in a configuration grant resource overlapping with a COT.
12A is a conceptual diagram illustrating a first embodiment of a method for changing a downlink transmission bandwidth and a method for indicating a transmission bandwidth in a COT initiated by a base station.
12B is a conceptual diagram illustrating a second embodiment of a method for changing a downlink transmission bandwidth and a method for indicating a transmission bandwidth in a COT initiated by a base station.
13A is a conceptual diagram illustrating a third embodiment of a method for changing a downlink transmission bandwidth and a method for indicating a transmission bandwidth in a COT initiated by a base station.
13B is a conceptual diagram illustrating a fourth embodiment of a method for changing a downlink transmission bandwidth and a method for indicating a transmission bandwidth in a COT initiated by a base station.
14 is a conceptual diagram illustrating a fifth embodiment of a method for changing a downlink transmission bandwidth and a method for indicating a transmission bandwidth in a COT initiated by a base station.
15 is a conceptual diagram illustrating a first embodiment of a method of extending a transmission bandwidth according to a PDSCH scheduling instruction.
16A is a conceptual diagram illustrating a first embodiment of a method for dynamically changing a PDCCH monitoring operation.
16B is a conceptual diagram illustrating a second embodiment of a method for dynamically changing a PDCCH monitoring operation.
17A is a conceptual diagram illustrating a third embodiment of a method for dynamically changing a PDCCH monitoring operation.
17B is a conceptual diagram illustrating a fourth embodiment of a method for dynamically changing a PDCCH monitoring operation.
18A is a conceptual diagram illustrating a first embodiment of a method of setting a frequency domain resource of a CORESET and a search space set.
18B is a conceptual diagram illustrating a second embodiment of a method of setting a frequency domain resource of a CORESET and a search space set.
19A is a conceptual diagram showing a third embodiment of a method for setting a frequency domain resource of a CORESET and a search space set.
19B is a conceptual diagram showing a fourth embodiment of a method for setting a frequency domain resource of a CORESET and a search space set.
19C is a conceptual diagram showing a fifth embodiment of a method of setting a frequency domain resource of a CORESET and a search space set.
19D is a conceptual diagram showing a sixth embodiment of a method for setting a frequency domain resource of a CORESET and a search space set.
20A is a conceptual diagram illustrating a first embodiment of a method for mapping a PDCCH DM-RS in a search space set.
20B is a conceptual diagram illustrating a second embodiment of a method for mapping a PDCCH DM-RS in a search space set.
20C is a conceptual diagram illustrating a third embodiment of a method for mapping a PDCCH DM-RS in a search space set.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

3A is a conceptual diagram showing a first embodiment of a bandwidth portion in a communication system, FIG. 3B is a conceptual diagram showing a second embodiment of a bandwidth portion in a communication system, and FIG. 3C is a third embodiment of a bandwidth portion in a communication system. It is a conceptual diagram showing an example.

3A to 3C, one bandwidth portion may include a plurality of LBT subbands. For example, one bandwidth portion may include four LBT subbands, and each LBT subband may have a bandwidth of 20 MHz. That is, it may be X _L =20. A transmitting node (eg, a base station or a terminal) may perform a CCA operation in units of LBT subbands before transmitting a signal and/or a channel. Depending on the result of the CCA operation, the channel(s) corresponding to some or all of the bandwidth portion may be occupied by the transmitting node, and the occupied channel(s) may be used for signal and/or channel transmission.

In the embodiment shown in Fig. 3A, the LBT operation performed at the transmitting node can succeed in all LBT subbands of the bandwidth portion. In this case, the transmitting node may transmit a signal and/or a channel using the entire band of the bandwidth portion. In the embodiment shown in FIG. 3B, the LBT operation performed in the transmitting node may succeed in LBT subbands #1, #3, and #4 belonging to the bandwidth portion. In this case, the transmitting node may transmit signals and/or channels using LBT subbands #1, #3, and #4.

In the embodiment shown in FIG. 3C, the LBT operation performed in the transmitting node may succeed in LBT subbands #1, #2, and #3 belonging to the bandwidth portion. In this case, the transmitting node may transmit signals and/or channels using LBT subbands #1, #2, and #3. In the embodiments, "the LBT operation is successful" means that the state of the channel is determined to be idle by an LBT operation (eg, a CCA operation) performed by a communication node (eg, a transmitting node). Can mean On the other hand, "LBT operation failed" means "the state of the channel is determined to be occupied by the LBT operation (eg, CCA operation) performed by the communication node (eg, the transmitting node)." can do.

Meanwhile, a guard band may be inserted between the LBT subbands included in the carrier and/or the bandwidth portion. The transmitting node may transmit a signal in the frequency domain excluding the guard band in the occupied LBT subband. Therefore, a normal channel sensing operation in an unoccupied LBT subband can be guaranteed. For example, in the embodiment shown in FIG. 3B, in order to ensure a normal channel sensing operation in LBT subband #2, guard bands may be inserted into LBT subbands #1 and #3, and the transmitting node is LBT Signals and/or channels may not be transmitted in the corresponding guard band in subbands #1 and #3. Therefore, interference to LBT subband #2 by communication using LBT subband #1 and/or #3 can be minimized. In the embodiment shown in Figure 3c, in order to ensure a normal channel sensing operation in the LBT subband #4, the guard band can be inserted into the LBT subband #3, and the transmitting node is the corresponding protection in the LBT subband #3. Signals and/or channels may not be transmitted in the band. Therefore, interference to the LBT subband #4 by communication using the LBT subband #3 can be minimized. The above-described guard band may be referred to as an in-carrier guard band in order to distinguish it from a guard band disposed outside a carrier bandwidth.

The configuration information of the LBT subband belonging to the carrier and bandwidth portion may be predefined for each "channel" to which the carrier and bandwidth portion are allocated. Also, configuration information of a guard band belonging to a carrier and a bandwidth portion may be predefined for each "channel" to which a carrier and a bandwidth portion are allocated. The configuration information of the LBT subband and the configuration information of the guard band include information indicating the number of LBT subbands constituting the carrier and/or bandwidth portion, information related to the set of RB(s) constituting each LBT subband, and carrier And/or information indicating the number of guard bands constituting the bandwidth portion, information related to a set of RB(s) constituting each guard band, and the like. For example, when the subcarrier spacing is 30 kHz, the bandwidth of one LBT subband having a bandwidth of 20 MHz may be defined to correspond to 51 consecutive RBs. When the subcarrier spacing is 15 kHz, the bandwidth of one LBT subband having a bandwidth of 20 MHz may be defined to correspond to 106 consecutive RBs. The configuration information of the LBT subband and/or the configuration information of the guard band may be shared in advance between the base station and the terminal.

Alternatively, the base station may transmit one or more information elements (eg, one or more parameters) among the configuration information of the LBT subband and the configuration information of the guard band to the terminal through signaling. For example, information related to the set of RB(s) constituting each LBT subband in the carrier and/or information indicating the number of LBT subbands may be signaled to the terminal. For another example, information related to the set of RB(s) constituting each guard band in the carrier and/or information indicating the number of guard bands may be signaled to the terminal. Alternatively, both information on the LBT subband and information on the guard band may be signaled to the terminal. In this case, the minimum number of RBs that the guard band can have may be 0. For example, the start RB index of a guard band may be set to be the same as the end RB index, and the terminal may receive configuration information of the guard band from the base station. In this case, the UE may consider that the size of the corresponding guard band is 0. That is, the LBT subbands that are logically adjacent to the guard band may be physically adjacent to each other without the guard band. The configuration information (eg, configuration information) of the guard band may be signaled to the terminal together with the configuration information of the carrier and/or bandwidth portion.

The sum 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 (hereinafter, collectively referred to as “carrier”). That is, each RB constituting the carrier may belong to at least one LBT subband or guard band. At the same time or separately, each LBT subband and RB sets constituting each guard band may be disjoint sets (ie, the intersection may be an empty set). That is, each RB constituting a carrier may belong to only one LBT subband or may belong to only one guard band. Alternatively, the LBT subbands and guard bands may have an intersection with each other. That is, a certain RB may belong to a plurality of LBT subbands. Alternatively, some RBs may belong to the LBT subband and the guard band at the same time.

In embodiments, signaling is physical (PHY) signaling (e.g., DCI), medium access control (MAC) signaling (e.g., MAC CE (control element)), and RRC signaling (e.g., MIB (master information block), system information block (SIB), cell-specific RRC signaling, terminal-specific RRC signaling, etc.). In addition, in the following description, unless otherwise noted, signaling (or setting) may mean both signaling (or setting) by an explicit method and signaling (or setting) by an implicit method.

In the communication of the unlicensed band, the transmitting node can occupy a channel for a certain time when the LBT operation is successful. In this case, the channel occupancy time or the channel occupancy period may be referred to as “channel occupancy time (COT)”. "The sending node succeeds in the LBT operation" may mean "the sending node has secured the COT". The transmitting node may transmit a signal and/or a channel using some or all of the COT that it initiated. In addition, the COT initiated by the transmitting node may be shared with a receiving node (eg, a communication node performing a receiving operation). In the COT shared between the transmitting node and the receiving node, the receiving node can perform not only the receiving operation but also the transmitting operation. Therefore, the transmitting node can perform not only the transmission operation but also the reception operation within the shared COT. In embodiments, a transmitting node may mean a node that has initiated or initiated a COT (for example, an initiating node), and a receiving node is a signal from a corresponding COT without starting or initiating a COT. It may mean a node that transmits/receives.

The terminal may transmit a data channel in a carrier or a guard band within a bandwidth portion. Alternatively, the terminal may not be able to transmit the data channel in the guard band within the carrier or bandwidth portion. The terminal may determine whether to transmit the data channel in the guard band within the carrier or bandwidth portion according to the COT or the time interval within the transmission burst interval. The guard band (eg, guard RB(s)) may be regarded as a reserved resource. The protection RB(s) may be set as a reserved resource, and the terminal may transmit and receive a data channel (eg, PUSCH, PDSCH, PSSCH) by performing a rate matching operation on the reserved resource. The terminal may map the data channel to a resource region excluding the reserved resource, and may transmit the mapped data channel. The above-described operation of the terminal may be performed when some or all of the reserved resources are included in the resource region of the data channel.

4A is a conceptual diagram showing a first embodiment of a communication method within a COT.

Referring to FIG. 4A, a base station (eg, gNB) may acquire a COT by performing a CCA operation. The base station may transmit a downlink transmission burst at the beginning of the COT. The downlink transmission burst may be a set of consecutive downlink signals and/or channels in the time domain. The uplink transmission burst may be a set of consecutive uplink signals and/or channels in the time domain. When signals and/or channels constituting a downlink and uplink transmission burst are continuous in the time domain, it may mean that a gap between transmissions of signals and/or channels is less than or equal to a reference value. For example, the reference value may be 0 or 16 μs. The COT initiated by the base station may be shared with the terminal. The terminal may transmit an uplink transmission burst within the shared COT.

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

4B is a conceptual diagram showing a second embodiment of a communication method within a COT.

Referring to FIG. 4B, the UE may acquire a COT by performing a CCA operation. The UE may transmit an uplink transmission burst at the beginning of the COT. The COT initiated by the terminal may be shared with the base station. The base station may transmit a downlink transmission burst within the shared COT. In this case, the base station may perform an LBT operation for transmission of a downlink transmission burst. For example, the base station may perform a CCA operation after transmission of an uplink transmission burst is finished. When it is determined that the channel state is the idle state as a result of the CCA operation, the base station may transmit a downlink transmission burst. Alternatively, the base station may transmit a downlink transmission burst without performing a CCA operation. For example, if the time interval (eg, T2) between the uplink transmission burst and the downlink transmission burst is less than a preset value (eg, 16 μs), the base station performs a downlink transmission burst without performing a CCA operation. Can send. T2 may be a time interval between the end point of the uplink transmission burst and the start point of the downlink transmission burst.

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

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

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

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

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

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

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

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

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

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

Embodiments can be applied not only for a COT initiated by a base station but also for a COT initiated by a terminal.

5 is a conceptual diagram showing a first embodiment of a bandwidth portion set asymmetrically in a time division duplex (TDD)-based communication system.

5, a downlink bandwidth portion (eg, an active (or activated) downlink bandwidth portion) and an uplink bandwidth portion (eg, an active (or activated) uplink bandwidth portion) are It can be set in the terminal. The frequency domain of the downlink bandwidth portion may be different from the frequency domain of the uplink bandwidth portion. The downlink bandwidth portion may include LBT subbands #1 to #4, and each of the LBT subbands #1 to #4 may correspond to channels #1 to #4. The uplink bandwidth portion may include LBT subbands #1 and #2, and each of LBT subbands #1 and #2 may correspond to channels #2 and #3.

The downlink bandwidth portion and the uplink bandwidth portion may share channels #2 and #3. In this case, channel #2 may correspond to LBT subband #2 of the downlink bandwidth part and LBT subband #1 of the uplink bandwidth part. Channel #3 may correspond to LBT subband #3 of the downlink bandwidth portion and LBT subband #2 of the uplink bandwidth portion. In the following embodiments, when an operation such as channel access, transmission, measurement, etc. is described on a certain bandwidth portion, the corresponding bandwidth portion may mean an active (or activated) bandwidth portion.

When the LBT subband is a component of the bandwidth portion, the LBT subband of the downlink bandwidth portion corresponding to the specific channel may be different from the LBT subband of the uplink bandwidth portion corresponding to the specific channel. That is, the LBT subband A of the downlink bandwidth portion may correspond to the LBT subband B of the uplink bandwidth portion. Considering the above definition, “CCA operation (eg, LBT operation), COT acquisition operation, and signal transmission operation in the bandwidth portion” refers to “CCA operation in one or more LBT subbands belonging to the bandwidth portion (for example, For example, it may mean an LBT operation), a COT acquisition operation, and a signal transmission operation. "CCA operation (eg, LBT operation), COT acquisition operation, and signal transmission operation in LBT subband(s) belonging to the bandwidth part" means "CCA operation in channel(s) corresponding to LBT subband(s) (Eg, LBT operation), COT acquisition operation, and signal transmission operation".

The downlink bandwidth portion (or LBT subband belonging to the downlink bandwidth portion) and the uplink bandwidth portion (or LBT subband belonging to the uplink bandwidth portion) corresponding to a specific channel may be used without distinction. In embodiments, the LBT subband included in the downlink bandwidth part may be referred to as a "downlink LBT subband", and the LBT subband included in the uplink bandwidth part may be referred to as a "uplink LBT subband". I can.

[COT acquisition method and signal transmission method]

When a plurality of downlink transmission bursts are transmitted within one COT, transmission bandwidths of the plurality of downlink transmission bursts may be different from each other. In addition, when a plurality of uplink transmission bursts are transmitted within one COT, transmission bandwidths of the plurality of uplink transmission bursts may be different from each other. That is, the base station can change the transmission bandwidth of the downlink transmission burst within one COT, and the terminal can change the transmission bandwidth of the uplink transmission burst within one COT. This operation may be referred to as “method 100”. The change of the transmission bandwidth may mean a combination of one or more of reduction, expansion, and movement of the transmission bandwidth. Method 100 may be applied when the downlink bandwidth portion or the uplink bandwidth portion includes a plurality of LBT subbands.

6 is a conceptual diagram illustrating a first embodiment of a method for obtaining a COT and a method for transmitting a signal in a bandwidth portion including a plurality of LBT subbands.

Referring to FIG. 6, the downlink bandwidth portion may include four LBT subbands, and the uplink bandwidth portion may include two LBT subbands. LBT subbands #2 and #3 of the downlink bandwidth portion (e.g., downlink LBT subbands #2 and #3) each of the LBT subbands #1 and #2 of the uplink bandwidth portion (e.g., uplink Link LBT subbands #1 and #2) may correspond. The base station can perform the CCA operation in the bandwidth portion (eg, LBT subband(s) or channel(s) corresponding to the bandwidth portion activated in the terminal), and one or more LBT subbands belonging to the bandwidth portion Can occupy a channel in CCA operation may mean LBT operation.

That is, the base station may acquire the COT in one or more LBT subbands. The base station may acquire the COT in the downlink LBT subband #2, and transmit a downlink transmission burst (hereinafter, referred to as “first downlink transmission burst”) from the acquired COT. In an embodiment, the COT (eg, one COT in the bandwidth portion) may mean the COT obtained by the base station at t1 of the downlink LBT subband #2.

After the transmission of the first downlink transmission burst is finished, the terminal may transmit an uplink transmission burst (hereinafter referred to as “first uplink transmission burst”) within the COT initiated by the base station. The terminal may perform an LBT operation before transmitting the first uplink transmission burst. The LBT operation may be performed within the T1 period. In this case, the terminal may perform an LBT operation in the LBT subband(s) (or channel(s)) to which the COT acquired by the base station belongs, and transmit a signal and/or a channel according to the result of the LBT operation. have. This operation may be referred to as “method 110”.

In embodiments, "LBT subband(s) to which the COT acquired by the base station belongs" may mean "LBT subband(s) that the terminal considers to belong to the COT acquired by the base station". Whether or not to acquire the COT will be described in terms of the base station, but can also be interpreted in terms of the terminal. The terminal may check the LBT subband(s) to which the COT acquired by the base station belongs through a signal detection operation or reception of control information. The UE may assume a specific LBT subband(s) as the LBT subband(s) to which the COT acquired by the base station belongs, and the LBT subband(s) assumed by the UE belong to the actual LBT to which the COT acquired by the base station belongs. It may be different from the subband(s). "When the base station informs the terminal of some LBT subband(s) among all LBT subbands to which the COT belongs" or "Some LBT subband(s) among all LBT subbands to which the COT obtained by the base station belongs When the information of "failed", the LBT subband(s) assumed by the UE may be different from the actual LBT subband(s) to which the COT acquired by the eNB belongs.

In an embodiment, the UE may perform the LBT operation in the uplink LBT subband #1 corresponding to the downlink LBT subband #2 to which the COT acquired by the base station belongs, and the first uplink in the uplink LBT subband #1 Transmit bursts can be transmitted. Even when the uplink LBT subband #2 is included in the uplink bandwidth portion, the UE may not perform the LBT operation and signal transmission in the uplink LBT subband #2. Even when information instructing to transmit a signal and/or channel (eg, PUSCH) in the uplink LBT subband #2 is received from the base station, the terminal does not perform the LBT operation and signal transmission within the T2 period. I can. For example, when the PUSCH is scheduled by a dynamic grant in the uplink LBT subband #2 in the T2 period, the UE may not transmit the PUSCH in the uplink LBT subband #2 in the T2 period.

Or, in the uplink LBT subband #2 in the T2 interval, the PUSCH is scheduled by a configured grant, and uplink data to be transmitted through the scheduled PUSCH (e.g., uplink shared channel (UL-SCH)) Even if is present, the UE may not transmit the PUSCH in the uplink LBT subband #2 within the T2 period. The LBT operation described above may be an LBT operation according to the first category. When a specific condition is satisfied, the UE may transmit a signal and/or a channel in the corresponding LBT subband without performing a CCA operation. For example, "when the T1 interval is less than a preset value (eg, 16 μs)" and/or "when it is instructed to perform an LBT operation according to the first category", the terminal 1 Uplink transmission burst can be transmitted.

On the other hand, the base station is "downlink LBT subband(s) to which the COT acquired by the base station belongs" and/or "downlink LBT subband(s) notified by the base station to the terminal (for example, the COT acquired by the base station belongs to A part or all of the downlink LBT subband(s)) can schedule an uplink data channel for the terminal in the uplink LBT subband(s) corresponding to ". In this case, the reference time point for determining whether to acquire the COT is the transmission time of an uplink grant including scheduling information of the uplink data channel (e.g., all symbol(s) of the PDCCH, the first symbol of the PDCCH) , A specific or arbitrary time in a downlink transmission burst interval including the PDCCH, etc.), a transmission time of an uplink data channel (e.g., all symbol(s) of the PUSCH, the first symbol of the PUSCH, the uplink including the PUSCH) It may be a specific or arbitrary point in time within the downlink transmission burst period immediately before the link transmission burst). The above-described method can be applied to a scheduling operation by a dynamic grant (eg, DCI).

For example, the base station can schedule the PUSCH within the first uplink transmission burst interval of the terminal in the uplink LBT subband #1 corresponding to the downlink LBT subband #2 to which the COT belongs in the first downlink transmission burst interval. have. That is, it may not be allowed for the base station to schedule the PUSCH in the uplink LBT subband #2 in the first uplink transmission burst period. The UE may not expect the PUSCH to be scheduled in the uplink LBT subband #2 in the first uplink transmission burst period. When the resource region of the PUSCH scheduled in the first uplink transmission burst period includes the uplink LBT subband #2, the UE may consider that the PUSCH scheduling error has occurred. The operation of the terminal described above may be based on the assumption that the terminal knows the LBT subband(s) to which the COT obtained by the base station belongs in the first downlink transmission burst interval. The above-described operation of the terminal may be implemented through detection of a downlink initial signal and acquisition of COT indication information.

Alternatively, the base station is the uplink data channel in all uplink LBT subband(s) of the terminal regardless of "whether to acquire COT in LBT subband(s)" or "whether to transmit configuration information of acquired COT" Can be scheduled. The reference time point for determining whether to acquire the COT may be the time point(s) described above. For example, the base station may schedule one PUSCH in the uplink LBT subbands #1 and #2 within the first uplink transmission burst period of the terminal or schedule a plurality of PUSCHs with one DCI. In this case, the UE may transmit the PUSCH on all scheduled frequency resources (eg, uplink LBT subbands #1 and #2). To this end, the UE may perform an LBT operation in the uplink LBT subband #2 as well as the uplink LBT subband #1. The LBT operation may be performed within the T1 period.

Alternatively, according to method 110, the terminal may perform the LBT operation in the LBT subband (for example, uplink LBT subband #1) to which the COT obtained by the base station belongs, and the PUSCH according to the result of the LBT operation. Can send. Even when the PUSCH is scheduled in the uplink LBT subband #2, the UE may not transmit the PUSCH in the uplink LBT subband #2. In this case, the base station may assume that the PUSCH is punctured in the PUSCH resource region of the uplink LBT subband #2, and may not receive the PUSCH in the PUSCH resource region of the uplink LBT subband #2. .

The above-described method can be applied when a scheduling operation is performed by a dynamic grant (eg, DCI). In addition, the above-described method can be applied when a scheduling operation by a configured grant, a grant-free scheduling operation, or a semi-persistent scheduling operation is performed. For example, a scheduling operation based on a dynamic grant (eg, DCI) is based on a cell-radio network temporary identifier (C-RNTI) or a modulation and coding scheme-C-RNTI (MCS-C-RNTI). Can correspond. Each of the scheduling operation according to the configuration grant, the grant-free scheduling operation, and the semi-permanent scheduling operation may correspond to a CS-RNTI (configured scheduling-RNTI) based scheduling operation.

For example, the UE may receive resource allocation information for the PUSCH of the uplink LBT subbands #1 and #2 through RRC signaling and/or DCI from the base station. Here, the PUSCH may be scheduled by a configuration grant. In this case, the UE is PUSCH in the uplink LBT subband #1 to which the COT acquired by the base station belongs among the uplink LBT subbands #1 and #2 (for example, the LBT subband to which the COT shared between the base station and the UE belongs). May be transmitted, and PUSCH may not be transmitted in uplink LBT subband(s) other than the uplink LBT subband #1.

Meanwhile, when the type 2 configuration grant method is used, the terminal may receive a DCI including information indicating activation or reconfiguration of the configuration grant resource. In this case, the UE may transmit the PUSCH in the configuration grant resource (eg, the first period of the configuration grant resource) that is dynamically activated or reset by DCI. Since the configuration grant resource is dynamically indicated by the base station, when uplink data (e.g., UL-SCH) is present, the UE uses the configuration grant resource in the uplink LBT subband #2 in the T2 interval, as an exception. Thus, the PUSCH can be transmitted. According to the above-described method, the UE can transmit an uplink signal and/or a channel in “the LBT subband to which the COT shared with the base station belongs” or “the LBT subband dynamically indicated by the base station”. Therefore, the operation of the terminal may not violate the frequency regulation condition.

The above-described method is a configuration grant resource (e.g., PUSCH resource) as well as other uplink transmission resources (e.g., PUCCH (physical uplink control channel) resource, SRS (sounding reference signal) resource, PRACH ( Physical random access channel) resource, etc.) can also be used to perform communication.

The above-described method may be applied equally or similarly to other uplink signals and/or channels. For example, the above-described method may be applied in the same or similar manner to communication using a PUCCH resource, an SRS resource, a PRACH resource, etc., which are semi-fixedly set within an uplink bandwidth portion including one or more LBT subbands in an unlicensed band. For example, when a PUCCH resource, an SRS resource, a PRACH resource, etc. are set in the uplink LBT subband #2 in the T2 period, the terminal may transmit a corresponding signal and/or channel in the corresponding resource according to the above-described method. Alternatively, the terminal may not transmit the signal and/or channel in the corresponding resource according to the above-described method.

In the embodiment shown in FIG. 6, after the transmission of the first uplink transmission burst is finished, the base station may transmit a downlink transmission burst (hereinafter referred to as "second downlink transmission burst") within the COT. That is, the base station can transmit a plurality of downlink transmission bursts within one COT. The base station may perform the LBT operation before transmitting the second downlink transmission burst. The LBT operation for transmission of the second downlink transmission burst may be performed within the T2 period. That is, the base station may perform an additional LBT operation within the COT initiated by it.

The additional LBT operation may be the same or similar to the LBT operation performed by the base station immediately before the COT starts. For example, when the LBT operation based on the FBE operation method is applied, the base station immediately before the start of the COT (for example, in the idle period) in each LBT subband according to the second category or the 2-1 category LBT The operation can be performed. In addition, the base station may additionally perform an LBT operation according to the second category or the 2-1 category in each LBT subband to transmit an additional downlink transmission burst within the COT.

The additional LBT operation may be an operation separate from the LBT operation performed by the base station immediately before COT starts. For example, when the LBT operation based on the FBE operation method is applied, the base station immediately before the start of the COT (for example, in the idle period) in each LBT subband according to the second category or the 2-1 category LBT The operation can be performed. In addition, the base station may additionally perform an LBT operation according to the first category in each LBT subband in order to transmit an additional downlink transmission burst within the COT. That is, the base station may transmit an additional downlink transmission burst without a sensing operation in each LBT subband when a specific condition is satisfied within the COT. That is, the sensing operation (eg, LBT operation) may be omitted. The specific condition may be a condition in which the gap with the immediately preceding downlink or uplink transmission burst is less than or equal to a reference value.

Alternatively, the LBT operation applied for each LBT subband may be different. In the proposed method, the base station can perform an LBT operation (eg, an LBT operation according to the first or second category) without a random backoff operation in some LBT subband(s) of the downlink bandwidth, and the same A random backoff-based LBT operation (eg, an LBT operation according to a third or fourth category) may be performed in the remaining LBT subband(s) of the downlink bandwidth portion. This operation may be referred to as “method 111”.

Some LBT subband(s) to which the LBT operation according to the first or second category is applied are the LBT subband(s) to which the COT obtained by the base station belongs to the time point at which the LBT operation is performed or before the time point at which the LBT operation is performed. Can be In some LBT subband(s), a time interval between a downlink transmission burst interval and an uplink transmission burst interval before the corresponding downlink transmission burst interval may be less than or equal to a preset value. For example, in some LBT subband(s), if the time interval between a downlink transmission burst interval and an uplink transmission burst interval before the corresponding downlink transmission burst interval is 16 μs or 25 μs or less, the base station may use some LBT subbands ( S) may perform an LBT operation according to the first or second category.

In the embodiment shown in Figure 6, the base station is at least one LBT subband (e.g., downlink LBT subband #2) of the LBT subband (s) to which the acquired COT belongs to an uplink transmission burst ( For example, a first uplink transmission burst) may be received. According to method 111, the base station according to the second category in the downlink LBT subband #2 in order to transmit a downlink transmission burst (e.g., a second downlink transmission burst) after reception of the first uplink transmission burst. LBT operation can be performed. Alternatively, the base station may transmit the second downlink transmission burst by performing the LBT operation according to the first category in the downlink LBT subband #2. That is, in the downlink LBT subband #2, the LBT operation may be omitted. The LBT operation according to the first or second category may be performed within the period T4.

The embodiment shown in FIG. 6 may be implemented by other methods. The base station dynamically allocates an uplink transmission or an uplink transmission burst (e.g., PUSCH) to the terminal(s) among the LBT subband(s) to which the acquired COT belongs (e.g. For example, only downlink LBT subband #2) transmits a downlink transmission burst (eg, a second downlink transmission burst) after the uplink transmission or uplink transmission burst period (eg, T2 period). can do. In this case, the base station may transmit a downlink transmission burst when the LBT operation is successful in the LBT subband(s) regardless of whether the uplink transmission is detected or received.

In addition, according to the method 111, the base station is the third or third in the LBT subband(s) in which the first uplink transmission burst is not received (eg, downlink LBT subbands #1, #3, and #4). LBT operation according to 4 categories can be performed, and a second downlink transmission burst can be transmitted in the LBT subband(s) (e.g., downlink LBT subbands #1 and #3) in which the LBT operation is successful. . In this case, the random backoff value for the LBT operation in the corresponding LBT subband(s) may be independently managed. In the corresponding LBT subband(s), the LBT operation may be paused while the first downlink transmission burst is transmitted, and resumed after the transmission of the first downlink transmission burst is finished.

For example, the random backoff value for LBT operation in the corresponding LBT subband(s) may be maintained while the first downlink transmission burst is transmitted. Alternatively, the random backoff value for the LBT operation in the corresponding LBT subband(s) may be initialized at the end of the first downlink transmission burst. That is, the base station may reselect the random backoff value within the contention window. In this case, the contention window updated by transmission of the first downlink transmission burst may be used. Meanwhile, a common contention window and/or a common random backoff value may be used for the LBT subband(s). That is, the LBT operation in the LBT subband(s) constituting one bandwidth portion may be performed using a common contention window and/or a random backoff value. The above-described method can be applied even when a common random backoff value is used.

In order to align the signal transmission start time (eg, t3) in the downlink LBT subbands #1 to #4, the base station is self-deferral for LBT operation in the remaining LBT subband(s). The method can be applied. For example, the base station may perform the LBT operation again (e.g., the LBT operation according to the second category) without a random backoff operation after a certain time from the time when the LBT operation is successful, and the LBT operation is successful. It is possible to transmit signals and/or channels in the LBT subband(s). The LBT operation according to the third or fourth category may be performed within the period T2.

Alternatively, the base station may perform the LBT operation according to the second category in the downlink LBT subbands #1, #3, and #4, and the second downlink in the downlink LBT subband(s) in which the LBT operation is successful. Link transmission bursts can be transmitted. In this case, the base station may regard the downlink LBT subband #2 as the primary LBT subband, and the remaining LBT subbands according to a signal transmission time or an expected signal transmission time (eg, t3) in the primary LBT subband. It is possible to determine when the LBT operation is performed in the bands. For example, the base station may perform an LBT operation according to the second category in the remaining LBT subband(s) during a preset time period (eg, 25 μs) before t3. In addition, the terminal may perform an LBT operation according to the second category or the first category in the primary LBT subband.

Meanwhile, the base station may expect to receive an uplink transmission burst in the LBT subband(s) to which the acquired COT belongs. However, the base station may not be able to receive the uplink transmission burst in the corresponding LBT subband(s). For example, in the embodiment shown in FIG. 6, the base station may not receive the first uplink transmission burst within the period T2. In this case, the base station may perform LBT according to the first or second category in order to transmit the second downlink transmission burst in the downlink LBT subband #2. In this case, the LBT operation according to the second category may be performed in the remaining LBT subbands (eg, downlink LBT subbands #1, #3, and #4) by the above-described method.

Alternatively, the base station may perform a random backoff-based LBT operation (eg, an LBT operation according to a third or fourth category) in the remaining LBT subbands. In this case, the base station may perform a random backoff-based LBT operation (for example, an LBT operation according to the third or fourth category) or an LBT operation according to the second category in the remaining LBT subbands, and the LBT operation The second downlink transmission burst can be transmitted in the successful LBT subband(s). A specific LBT operation in the corresponding LBT subbands may be performed according to the above-described method.

When the additional LBT operation is successful in one or more LBT subbands of the downlink LBT subbands #1, #3, and #4 in the T2 period, the base station uses the one or more LBT subbands for which the additional LBT operation is successful. Link transmission bursts can be transmitted. In the embodiment shown in Figure 6, the base station can succeed in the LBT operation in the downlink LBT subbands #1 to #3 in the period T2, and the second downlink in the downlink LBT subbands #1 to #3 in which the LBT operation is successful Link transmission bursts can be transmitted. That is, the base station can extend the downlink transmission bandwidth in the COT by additionally performing the LBT operation in the uplink period in the COT. This operation may be an embodiment of method 100. The second downlink transmission burst may be transmitted at the same time (eg, t3) in the downlink LBT subbands #1 to #3.

In the embodiment shown in FIG. 6, the transmission bandwidth of the second downlink transmission burst may basically include the downlink LBT subband #2, and additionally include the downlink LBT subband(s) in which the LBT operation is successful. can do. The transmission bandwidth of the second downlink transmission burst may consist of consecutive downlink LBT subband(s) in the frequency domain. The above-described method can be used in combination with Method 111. Therefore, when the LBT operation (e.g., LBT operation according to the first or second category) fails in the T2 period or the T4 period in the downlink LBT subband #2, the base station is also in the remaining downlink LBT subband(s). It can be considered that the LBT operation has failed. Therefore, the base station may not transmit the downlink transmission burst at t3. In this case, the base station may release the COT acquired at t1, and may perform a new LBT operation in the corresponding bandwidth portion. To this end, the base station may initialize a random backoff value for the corresponding LBT subband(s).

In the embodiment shown in FIG. 6, the UE may transmit an uplink transmission burst (hereinafter, referred to as “second uplink transmission burst”) after the transmission of the second downlink transmission burst is completed within the COT. That is, the UE can transmit a plurality of uplink transmission bursts within one COT. The terminal may perform an LBT operation before transmitting the second uplink transmission burst. The LBT operation may be performed within the period T3. According to method 110, the terminal may perform an LBT operation in the LBT subband(s) or channel(s) to which the COT acquired by the base station belongs, and transmit a signal and/or a channel according to the result of performing the LBT operation. have.

Alternatively, the UE may perform an LBT operation in the LBT subband(s) included in the uplink bandwidth portion. In the embodiment shown in FIG. 6, the UE includes the LBT subband(s) included in the uplink bandwidth part of the LBT subband(s) to which the COT acquired by the base station belongs (e.g., uplink LBT subband #1 And #2) can perform the LBT operation, and can transmit the second uplink transmission burst in the uplink LBT subbands #1 and #2 in which the LBT operation is successful.

In addition, in the case of uplink data channel (e.g., PUSCH) transmission, the terminal can perform the LBT operation in the LBT subband(s) to which the uplink data channel (e.g., PUSCH) scheduled by the base station belongs. have. In the embodiment shown in FIG. 6, the PUSCH of the uplink LBT subbands #1 and #2 may be scheduled at t4. The second uplink transmission burst may be transmitted through the uplink LBT subbands #1 and #2 at the same time point (eg, t4). The UE can extend the uplink transmission bandwidth within one COT. This operation may be another embodiment of method 100. Other embodiments of Method 100 will be described below.

7A is a conceptual diagram showing a second embodiment of a method for obtaining COT and a method for transmitting a signal in a bandwidth portion including a plurality of LBT subbands, and FIG. 7B is a method for obtaining COT in a bandwidth portion including a plurality of LBT subbands, and A conceptual diagram showing a third embodiment of a signal transmission method.

Referring to FIGS. 7A and 7B, a portion of a bandwidth set in a terminal may include two LBT subbands. The bandwidth portion may be an active bandwidth portion. The bandwidth portion may mean a downlink bandwidth portion or an uplink bandwidth portion. The base station can acquire the COT by performing the LBT operation in the bandwidth portion. The start point of the COT may be t1, and the end point of the COT may be t4.

In the embodiment shown in FIG. 7A, the base station can extend the downlink transmission bandwidth within one COT. That is, the base station can transmit the first downlink transmission burst through the LBT subband #1 in the interval from the start point of the COT (eg, t1) to t2, and the LBT subband in the interval from t3 to t4. A second downlink transmission burst can be transmitted through #1 and #2. In addition, the UE can receive the first downlink transmission burst through LBT subband #1 in the interval from t1 to t2, and the second downlink transmission burst through LBT subbands #1 and #2 in the interval from t3 to t4. Link transmission bursts can be received.

For this operation, the base station may perform the LBT operation in the LBT subbands #1 and #2 in the period between t2 and t3 (eg, period T1). When the LBT operation is successful in LBT subbands #1 and #2, the base station may transmit a second downlink transmission burst in LBT subbands #1 and #2. The T1 period may be used as a paused duration or an uplink (UL) period. The base station may not perform a transmission/reception operation of a signal and/or a channel other than a reception operation of a signal and/or a channel according to the LBT operation in the idle period. Alternatively, the T1 period may include both an idle period and an uplink period. The LBT operation may be an LBT operation according to the first or second category. In this embodiment, the'uplink period' may mean a period in which the base station performs a reception operation, and the period in which the base station performs a reception operation is a'uplink period composed of uplink symbol(s) by setting a slot format. It can be distinguished from'section'.

In the embodiment shown in FIG. 7B, the base station can reduce the downlink transmission bandwidth within one COT. That is, the base station may transmit the first downlink transmission burst through the LBT subbands #1 and #2 in the interval from the start point of the COT (eg, t1) to t2, and in the interval from t3 to t4 A second downlink transmission burst may be transmitted through the LBT subband #1. In addition, the UE can receive the first downlink transmission burst through LBT subbands #1 and #2 in the interval from t1 to t2, and the second downlink transmission burst through LBT subband #1 in the interval from t3 to t4. Link transmission bursts can be received.

For this operation, the base station may perform the LBT operation in the LBT subbands #1 and #2 in the period between t2 and t3 (eg, period T1). If the LBT operation is successful in LBT subband #1, the base station may transmit a downlink transmission burst in LBT subband #1. Here, in LBT subband #2, the LBT operation may fail.

Alternatively, the base station may not perform the LBT operation in the LBT subband #2 in the period T1. That is, the base station can perform the LBT operation only in the LBT subband #1 in the period T1. The base station may perform an additional LBT operation in some LBT subband(s) among all LBT subbands belonging to the bandwidth part of the COT, and in one or more LBT subbands in which the LBT operation is successful among some LBT subband(s). A downlink signal and/or channel can be transmitted. The T1 period may be used as an idle period and/or an uplink period. The LBT operation may be an LBT operation according to the first or second category.

According to the above-described embodiments, the base station and/or the terminal may occupy a channel at different time points for each LBT subband or for each channel within one carrier and one bandwidth portion. For example, in the embodiment shown in FIG. 6, the base station may occupy LBT subband #2 of the downlink bandwidth portion at t1, and occupy LBT subbands #1 and #3 of the downlink bandwidth portion at t3. can do. In this case, the COT can be defined by the following two methods.

In the first COT definition method, the base station and the terminal may assume one COT (eg, common COT) within one carrier regardless of the number of LBT subbands constituting the downlink and uplink bandwidth portions. . In this case, one COT may be set based on the channel occupancy time point by the initial LBT operation performed by the base station or the terminal. This operation may be referred to as “method 120”. Specifically, one COT may be set based on the channel occupancy time point by the initial LBT operation performed "after the base station or the terminal releases the previous COT" or "after the base station or the terminal initializes the previous LBT operation" have. In the embodiment shown in FIG. 6, according to the method 120, the start time of the COT may be t1, and the end time of the COT may be t5.

In the second COT definition method, the base station and the terminal may assume a plurality of COTs in one carrier. For example, when the downlink and/or uplink bandwidth portion includes a plurality of LBT subbands or a plurality of channels, the base station and the terminal may assume a COT for each LBT subband or for each channel. For example, the start time, end time, and/or duration of the COT may be different for each LBT subband or for each channel. This operation may be referred to as "Method 121".

In the embodiment shown in FIG. 6, according to method 121, the start time of COT in downlink LBT subband #2 may be t1, and the start time of COT in downlink LBT subband #1 and #3 is t3. I can. In downlink LBT subbands #1 to #3, the end time of the COT may be the same as t5. When method 121 is used, the end points of one or more COTs in one carrier may be the same. That is, even when channels are occupied at different times in a plurality of LBT subbands in one carrier, the base station or the terminal may release the channel at the same time. This operation may be referred to as “method 122”.

Meanwhile, the number of switching between downlink communication and uplink communication within one COT may be limited. For example, when a specific condition is satisfied, only one downlink transmission burst may be allowed to be transmitted within one COT initiated by the base station. In addition, only one uplink transmission burst may be transmitted within one COT initiated by the base station. In this case, in the COT initiated by the base station, the uplink period may be arranged in the end region of the COT. For another example, when certain conditions are satisfied, only one uplink transmission burst may be allowed to be transmitted within one COT initiated by the terminal. In addition, only one downlink transmission burst can be transmitted within one COT initiated by the terminal.

A maximum of one downlink period may be indicated or set within the COT (eg, a COT initiated by the terminal). In this case, one downlink period may be arranged in the end region of the COT. For example, the operation of limiting the number of switching between downlink communication and uplink communication may be applied when the bandwidth of the carrier or the bandwidth portion exceeds a preset value. For example, the preset value may be a bandwidth (eg, 20 MHz) occupied by one LBT subband.

Alternatively, the operation of limiting the number of switching between downlink communication and uplink communication may be applied when the carrier or bandwidth portion includes two or more LBT subbands. The base station transmits configuration information indicating the number of uplink transmission bursts (eg, the maximum number) and/or the number of downlink transmission bursts (eg, the maximum number) within the COT initiated by the terminal to the terminal. I can. Here, the configuration information may be transmitted from the base station to the terminal through RRC signaling. In addition, the configuration information may be transmitted to the terminal together with the configuration information of the bandwidth portion.

[COT instruction method]

In the proposed method, the operation of the terminal may be performed based on the configuration information of the COT received from the base station. The COT configuration information may include information related to the COT acquired by the base station and/or information related to the LBT subband to which the COT acquired by the base station belongs. Accordingly, for broadband operation in an unlicensed band, the base station may inform the terminal of information of a COT initiated by itself and/or information of an LBT subband to which the corresponding COT belongs.

The base station may inform the terminal of the configuration information of the COT initiated by itself through signaling. Signaling may be physical layer signaling. For example, the group common DCI transmitted to one or more terminal groups may include COT configuration information. In the NR communication system, DCI format 2_0 may be used as a group common DCI. The UE may obtain DCI format 2_0 by receiving the group common PDCCH from the PDCCH CSS set, and may obtain COT configuration information from DCI format 2_0. The DCI format 2_0 may include other information (eg, information related to the slot format (eg, SFI)) in addition to the COT configuration information. Alternatively, a new DCI format extended based on DCI format 2_0 may be used as a group common DCI.

The base station may transmit one or more consecutive slots and information on the slot format of each slot (hereinafter referred to as "slot format configuration information") to the terminal through the SFI. When one or more slot format configuration information is set by higher layer signaling (eg, RRC signaling), one of the one or more slot format configuration information is DCI (eg, group common DCI, DCI format). 2_0). The SFI may include slot format configuration information for one or more carriers. The method of indicating slot format setting information by SFI can be used in both licensed band communication and unlicensed band communication.

For another example, the COT configuration information may be signaled to the terminal through a plurality of sequences forming a physical layer signal. Each of the plurality of sequences may be a sequence of a reference signal or a synchronization signal. The reference signal is a DM-RS, CSI-RS for decoding a broadcast channel (eg, a physical broadcast channel (PBCH)), a control channel (eg, PDCCH), and a data channel (eg, PDSCH) ( channel state information-reference signal). The synchronization signal may be a primary synchronization signal (PSS), a secondary synchronization signal (SSS), or the like. The base station may transmit one sequence among a plurality of predefined sequences between the base station and the terminal to the terminal. The terminal may obtain COT configuration information by receiving a sequence from the base station.

The COT configuration information may be signaled to the terminal in the start area of the COT. For example, the group common DCI including COT configuration information may be transmitted to the UE through the PDCCH in one or more of K symbols in the COT. Alternatively, the sequence of the downlink initial signal may be transmitted to the terminal in one or more symbols among K symbols in the COT, and the sequence of the downlink initial signal may indicate COT configuration information. Here, the K symbols may be the K-th symbols from the first symbol in the COT. K can be a natural number. For another example, the COT configuration information may be signaled to the terminal in the first slot in the COT. The UE may regard a slot in which a signal and/or a channel (eg, PDCCH) including COT configuration information is received as the first slot in the COT.

In the embodiment shown in FIG. 6, the start time of the COT may be different for each LBT subband or for each channel. In this case, the COT start time information may be indicated for each LBT subband or for each channel. COT start time information may be transmitted in each LBT subband or in a COT start region in each channel. In addition, the start time of the COT in the plurality of LBT subbands or channels may be the same. For example, in the embodiment shown in FIG. 6, the COT start time point in the downlink LBT subbands #1 and #3 may be the same as t3. In this case, the start time of COT for a plurality of LBT subbands or channels may be expressed as one or common control information. One or common control information may be signaled to the terminal by the method described above.

For another example, the end point of the COT for one or more LBT subbands or channels, the length of the COT (e.g., the total length of the COT, the remaining time of the COT), etc. may be expressed as one or common control information. I can. One or common control information may be signaled to the terminal by the method described above. When information indicating the remaining duration of the COT is received, the terminal receives the COT configuration information (e.g., one symbol among the symbol(s) in which DCI is received, the slot in which the DCI is received) , The end point of the COT may be derived based on the first symbol of the slot in which the DCI is received).

In addition, when information indicating the remaining time of the COT is received, the terminal may check the slot in which the COT is received among one or more slots indicated by the SFI based on the remaining time of the COT. When carrier aggregation is used, COT setting information for a plurality of carriers (eg, COT start time, COT end time, COT length (or duration), etc.) may be expressed as common control information. The common control information can be transmitted to the terminal through the above-described method, and the terminal can interpret the common control information according to the above-described method.

Meanwhile, the COT configuration information may not include SFI. For example, the group common DCI (eg, DCI format 2_0) may be set not to include SFI. Alternatively, a search space set for reception of the group common DCI (eg, DCI format 2_0) may not be set in the terminal. In this case, the terminal may determine the directions of symbols constituting the COT or transmission burst based on the semi-fixed slot format configuration information received from the base station. When semi-fixed slot format setting information is not received from the base station, the terminal may consider that all symbols constituting the COT or transmission burst are flexible symbols (eg, semi-fixed flexible symbols). Accordingly, the UE can perform a transmission operation of a signal and/or a channel (e.g., CSI-RS, SRS, PRACH, PUCCH, SS/PBCH block) based on information obtained through RRC signaling within the COT. And, it is possible to perform a PDCCH monitoring operation. Even in this case, other configuration information of the COT (eg, the length (or duration) of the COT, the end time of the COT, the start time of the COT, etc.) may be transmitted to the terminal by the above-described method.

The COT configuration information may further include a channel access priority class of the base station. The COT initiated by the base station can be shared with the terminal, and the terminal can perform uplink communication in the shared COT. In this case, the UE may transmit a PUSCH or PUCCH having the same or lower priority as the channel access priority class of the base station. Information indicating whether the above-described configuration information of each COT is included in the DCI, the size of the configuration information of each COT (e.g., number of bits), etc. are set to the terminal through higher layer signaling (e.g., RRC signaling) Can be.

The base station may occupy one or more LBT subbands by performing an LBT operation, and may inform the terminal of configuration information of the occupied one or more LBT subbands. Setting information of one or more occupied LBT subbands may be included in the setting information of the COT. Alternatively, the configuration information of one or more occupied LBT subbands may be transmitted to the terminal together with the configuration information of the COT. The set of LBT subband(s) actually occupied by the base station may be different from the set of LBT subband(s) notified by the base station to the terminal. That is, the base station may inform the terminal that some or all of the LBT subband(s) occupied by the base station are available LBT subband(s). The terminal may assume that the COT is set in the LBT subband(s) indicated by the base station, and may perform communication within the COT.

According to method 122, one or more COTs within one carrier or bandwidth portion may have the same end time. On the other hand, the end point of the COT may be different for each LBT subband or for each channel. In this case, the COT end time information may be indicated for each LBT subband or for each channel. The COT end time information may be transmitted in each LBT subband or in the COT start region of each channel. In addition, when the end time of the COT is the same in a plurality of LBT subbands or channels, the end time of the COT may be expressed as one control information. One control information may be signaled to the terminal by the method described above.

COT configuration information may be repeatedly transmitted within one COT. For example, the base station may repeatedly transmit the configuration information of the COT initiated by the base station to the terminal. According to this operation, even when the setting information of the COT (for example, a signal indicating the setting information of the COT) is not received in the start area of the COT, the terminal sets the COT by receiving another signal repeatedly transmitted from the base station. Information can be obtained.

8 is a conceptual diagram showing a first embodiment of a method for repeatedly transmitting COT setting information.

Referring to FIG. 8, the base station may repeatedly transmit COT configuration information 4 times within a COT initiated by itself. For example, the base station may transmit the COT configuration information first from the start symbol constituting the COT or downlink transmission burst, and transmit the COT configuration information second from the first symbol of the second slot of the COT. In addition, the COT configuration information can be transmitted third from the 8th symbol of the second slot of the COT (eg, the middle of the PDSCH), and the fourth COT configuration information from the second symbol of the third slot of the COT Can be transmitted. COT configuration information in the first symbol of the second slot of the COT may be transmitted together with the downlink scheduling DCI.

은 1개의 슬롯이 포함하는 심볼들의 개수일 수 있고,

은 라디오 프레임 내의 슬롯 번호(예를 들어, 슬롯 인덱스)일 수 있고, l은 슬롯 내의 심볼 번호(예를 들어, 심볼 인덱스)일 수 있고, N_ID는 DM-RS의 스크램블링 ID 또는 물리계층 셀 ID일 수 있다.For example, the repeatedly transmitted COT configuration information may be included in the group common DCI, and the group common DCI may be transmitted through the PDCCH. In the NR communication system, the DM-RS of the PDCCH may be composed of a pseudo-noise (PN) sequence, and the PN sequence may be initialized based on Equation 1 below. The DM-RS of the PDCCH (ie, PDCCH DM-RS) may be a DM-RS used for demodulation of the PDCCH. In Equation 1,

May be the number of symbols included in one slot,

May be a slot number (eg, a slot index) in a radio frame, l may be a symbol number (eg, a symbol index) in a slot, and N _ID is a scrambling ID or physical layer cell ID of the DM-RS Can be

The base station can transmit the PDCCH in the start area of the COT, and the COT can start in any symbol of the slot. Therefore, in order to lower the PDCCH pre-processing complexity of the base station, the sequence of the PDCCH DM-RS and/or the scrambling sequence of the PDCCH is irrespective of the transmission time (eg, slot and symbol in which the PDCCH DM-RS is transmitted). Can be determined. For example, for the DM-RS of the group common PDCCH including COT configuration information, l may have a preset value (eg, l=0). l can be a fixed value.

는 COT 내에서의 슬롯 인덱스(예를 들어, COT의 시작 시점을 기준으로 정해지는 인덱스)일 수 있다. 예를 들어, COT의 k번째 슬롯의 인덱스는 (k-1)일 수 있다. 반면, COT의 설정 정보를 포함하는 DCI를 위한 PDCCH 외에 다른 DCI를 위한 PDCCH(예를 들어, 하향링크 또는 상향링크 스케줄링 DCI를 위한 PDCCH)의 DM-RS 시퀀스는 시간적으로 변경될 수 있다. NR 통신 시스템에서, COT의 설정 정보를 포함하는 PDCCH의 DM-RS 시퀀스는 수학식 1을 통해 생성될 수 있다. 이 경우, 신호 전송에 의해 야기되는 셀 간 간섭은 랜덤화될 수 있다.For example, for the DM-RS of the group common PDCCH including the setting information of the COT,

May be a slot index in the COT (eg, an index determined based on the start time of the COT). For example, the index of the k-th slot of the COT may be (k-1). On the other hand, the DM-RS sequence of the PDCCH for DCI other than the PDCCH for DCI including COT configuration information (eg, PDCCH for downlink or uplink scheduling DCI) may be temporally changed. In the NR communication system, the DM-RS sequence of the PDCCH including COT configuration information may be generated through Equation 1. In this case, inter-cell interference caused by signal transmission may be randomized.

In the embodiment shown in FIG. 8, a PDCCH (hereinafter, "the first PDCCH") different from the CORESET (eg, PDCCH monitoring occasion) in which the PDCCH (hereinafter referred to as "first PDCCH") including the setting information of the COT is transmitted 2 PDCCH") is transmitted CORESET (for example, PDCCH monitoring occasion) can share time and frequency resources. The above-described operation will be described with reference to FIG. 9 below.

FIG. 9A is a conceptual diagram illustrating a first embodiment of a method for mapping PDCCH and PDCCH DM-RS resources, and FIG. 9B is a conceptual diagram illustrating a second embodiment of a method for mapping PDCCH and PDCCH DM-RS resources.

Referring to FIGS. 9A and 9B, one CORESET may include 12 consecutive PRBs in the frequency domain and 2 consecutive symbols in the time domain. One CORESET may include 24 REGs. In the embodiment shown in FIG. 9A, a CORESET of the first PDCCH (e.g., a CORESET that is mutually combined (e.g., associated) with a search space set in which the first PDCCH is transmitted) or a PDCCH monitoring occasion for the first PDCCH ) And the CORESET of the second PDCCH may be disposed in the same time and frequency resources. Alternatively, the CORESET of the first PDCCH may be the same as the CORESET of the second PDCCH. In this case, the first PDCCH may be mapped to PRBs consisting of the first PRB to the third PRB in CORESET and PRBs consisting of the 7th PRB to 9th PRB in the CORESET. The second PDCCH may be mapped to PRBs consisting of the 10th PRB to the 12th PRB in CORESET. The first PDCCH may be a PDCCH including COT configuration information, and the second PDCCH may be a PDCCH not including COT configuration information.

In the embodiments illustrated in FIGS. 9A and 9B, the DM-RS sequence of the first PDCCH may be time-invariant, and the DM-RS sequence of the second PDCCH may be time-varying. In this case, if the CORESET of the first PDCCH and the CORESET of the second PDCCH share resources in the embodiment shown in FIG. 9A, the base station may transmit a narrowband DM-RS for demodulation of the first PDCCH and the second PDCCH. have. Collision between the DM-RS of the first PDCCH and the DM-RS of the second PDCCH can be avoided. When a broadband DM-RS is transmitted for demodulation of at least one of the first PDCCH and the second PDCCH, the mapping location of the DM-RS of the first PDCCH may collide with the mapping location of the DM-RS of the second PDCCH. . According to the above assumption, since the DM-RS sequence of the first PDCCH may be different from the DM-RS sequence of the second PDCCH, the first PDCCH without collision between the DM-RS of the first PDCCH and the DM-RS of the second PDCCH And it may be desirable to use a narrowband DM-RS to transmit all of the second PDCCH.

The narrowband DM-RS may refer to a DM-RS that is mapped only to REGs to which PDCCH is mapped among REGs constituting CORESET. The broadband DM-RS may mean a DM-RS mapped to all REGs of the cluster(s) to which the PDCCH is mapped among the cluster(s) constituting the CORESET. The cluster may mean a set of continuous PRB(s) in the frequency domain among PRB(s) constituting the CORESET. In the embodiments shown in FIGS. 9A and 9B, CORESET may be composed of one cluster, and one cluster may include 12 consecutive PRBs in the frequency domain.

Meanwhile, in the embodiment shown in FIG. 9B, only the first PDCCH may be transmitted in a specific CORESET or a specific PDCCH monitoring occasion. In this case, since there is no collision problem between PDCCH DM-RSs, the base station may transmit a wideband DM-RS for demodulation of the first PDCCH. When the wideband DM-RS is used, the PDCCH demodulation performance and the downlink transmission burst detection capability of the terminal may be improved.

The base station may transmit a specific PDCCH (eg, PDCCH including COT configuration information) along with a narrowband DM-RS or a broadband DM-RS according to the timing of the PDCCH monitoring occasion (or CORESET) of the terminal. In order to support both narrowband DM-RS transmission and wideband DM-RS transmission, the base station may dynamically change the type of PDCCH DM-RS (eg, wideband DM-RS or narrowband DM-RS). The base station may transmit the narrowband DM-RS together with the PDCCH for demodulation of the PDCCH in a CORESET and/or a specific PDCCH monitoring occasion of a search space set depending on the situation. Alternatively, the base station may transmit a wideband DM-RS together with the PDCCH for demodulation of the PDCCH in another specific PDCCH monitoring occasion. This operation may be referred to as “method 130”. For example, in the embodiments shown in FIGS. 9A and 9B, the base station may dynamically select a type of PDCCH DM-RS for transmission of the first PDCCH.

In method 130, the base station may transmit one of the wideband DM-RS and the narrowband DM-RS in one PDCCH monitoring occasion in the CORESET and/or search space set. The terminal may not know the type of the DM-RS transmitted by the base station in each PDCCH monitoring occasion. Accordingly, the UE can monitor both the wideband DM-RS and the narrowband DM-RS in each PDCCH monitoring occasion. In this case, the UE may attempt to detect the wideband DM-RS and the narrowband DM-RS according to a predetermined order.

Meanwhile, in one PDCCH monitoring occasion (or CORESET), the wideband DM-RS and the narrowband DM-RS may be simultaneously transmitted. For simultaneous transmission of the wideband DM-RS and the narrowband DM-RS, a subcarrier offset may be applied in the RE mapping procedure of the PDCCH DM-RS. When the PDCCH DM-RS (or a specific antenna port of the PDCCH DM-RS) is mapped with equal subcarrier spacing in the frequency domain, the subcarrier offset may be set to one of values from 0 to (D-1). D may mean a spacing between adjacent subcarriers to which the PDCCH DM-RS is mapped. When the PDCCH DM-RS is multiplexed on a plurality of different PDCCHs, a subcarrier offset may be set for each of the wideband DM-RS and the narrowband DM-RS. Information indicating whether to transmit or monitor a wideband DM-RS and/or narrowband DM-RS, a subcarrier offset for the corresponding DM-RS, etc. may be included in the setting information of CORESET, and the setting information of the CORESET is transmitted from the base station to the terminal. Can be signaled.

The base station or the terminal may change the downlink and/or uplink transmission bandwidth within one COT. In particular, according to the method proposed in the present invention, the base station or the terminal can extend the downlink and/or uplink transmission bandwidth by additionally performing the LBT operation within the COT. When the transmission bandwidth is dynamically changed within one COT, the end point of the COT may be changed. For example, if the downlink transmission bandwidth is extended in the middle of the COT, the base station terminates the downlink communication earlier than the predicted end of downlink communication at the time when the channel is occupied (eg, the start time of the COT). can do. In this case, the base station may advance the end point of the COT initiated by itself. Conversely, when the downlink transmission bandwidth is reduced in the middle of the COT, the base station may delay the end point of the COT initiated by itself.

In this case, the base station can reset the COT. The base station is the reset information of the changed COT (e.g., the reset COT) (e.g., the end time of the (changed) COT, the length (or duration) of the (changed) COT, the start time of the (changed) COT, etc.) Can be transmitted to the terminal. This operation may be referred to as “method 140”. COT reconfiguration information may be signaled from the base station to the terminal within the COT. According to method 140, when the (re)configuration information of the COT is transmitted multiple times within one COT, the (re)configuration information of different COTs may be transmitted at each transmission time point. In order to analyze the (re)configuration information of the k th COT received from the base station within one COT, the terminal (e.g., (k-1) th COT) of the COT previously received from the base station It may be unnecessary to know the (re)setting information).

The terminal may receive different COT configuration information (eg, the end time of the COT, the length (or duration) of the COT, the start time of the COT, etc.) within one COT. In this case, the terminal may consider that the configuration information of the last received COT is valid. For example, the terminal may receive configuration information of a plurality of COTs (eg, a plurality of group common DCIs, a plurality of DCIs having a format 2_0) within one COT, and configuration of a plurality of COTs End times of different COTs can be identified based on the information. In this case, the terminal may consider the end time of the COT derived through the configuration information of the last received COT to be valid. The terminal may perform an operation related to the COT based on the last received setting information of the COT.

The operation related to the COT may include a PDCCH monitoring operation, a discovery reference signal (DRS) reception operation, a HARQ-ACK report operation, an LBT operation, and the like. The DRS reception operation may include an operation of the UE receiving or detecting at least one of PSS, SSS, PBCH, and PBCH DM-RS. Further, the DRS reception operation may include a reception operation of a signal and/or a channel (eg, PDCCH, PDSCH, CSI-RS) additionally included in the DRS or combined with each other. Details of the PDCCH monitoring operation will be described below.

The LBT operation may include an operation of determining whether to transmit the setting grant PUSCH, an LBT operation for transmission of the setting grant PUSCH, and the like. The terminal may perform an LBT operation according to the fourth category (or the third category) within the COT initiated by the UE, and may transmit the configuration grant PUSCH using configuration grant resources. The configuration grant PUSCH may be a PUSCH scheduled by the configuration grant. Meanwhile, when the setting information of the COT is received, the terminal may check the setting grant resources belonging to the COT initiated by the base station based on the setting information of the COT. The terminal may not transmit the configuration grant PUSCH using configuration grant resources belonging to the COT initiated by the base station.

Alternatively, the terminal performs an LBT operation according to the changed LBT category (eg, the first or second category), thereby setting grant resources (eg, configuration grant resources belonging to the COT initiated by the base station). PUSCH can be transmitted. The above-described operation may be a predefined operation. Alternatively, the base station may instruct the terminal to perform the above-described operation.

The base station may inform the terminal of information indicating whether or not the configuration grant PUSCH can be transmitted within the COT initiated by the base station, an LBT category, and/or an LBT gap. For example, the base station may instruct the terminal to perform an LBT operation according to the second category for uplink transmission. In this case, the LBT gap set in the terminal may be 16 μs or 25 μs. Information indicating whether or not the configuration grant PUSCH can be transmitted within the COT initiated by the base station, the LBT category, and/or the LBT gap may be semi-fixedly set through RRC signaling. Alternatively, information indicating whether or not the configuration grant PUSCH can be transmitted within the COT initiated by the base station, the LBT category, and/or the LBT gap may be dynamically indicated through DCI. Here, the DCI may be a DCI (eg, group common DCI, DCI format 2_0) including the above-described COT configuration information.

Meanwhile, the time point at which the terminal finally receives the COT configuration information may be different for each LBT subband. For example, the configuration information of the COT last received by the terminal may include only the configuration information of the COT of some LBT subband(s). In this case, the above-described method can be applied for each LBT subband constituting the COT.

10 is a conceptual diagram illustrating a first embodiment of a method for transmitting a PUSCH in a configuration grant resource overlapping with a COT.

Referring to FIG. 10, a part of a configuration grant resource (eg, a configuration grant PUSCH resource) configured in a terminal may be included in a COT. The COT may be a COT initiated by a base station or a COT initiated by a terminal. The end point of the COT may be located in the middle of the duration of the configuration grant resource set in the terminal. Configuration grant resources set in the terminal may include configuration grant resources #1 to #3. The configuration grant resource #1 may completely belong to the COT, some of the configuration grant resource #2 may belong to the COT, and the configuration grant resource #3 may not belong to the COT. When the COT is the COT initiated by the base station, the terminal may obtain the end time of the COT based on the above-described method.

In this case, the terminal may transmit the configuration grant PUSCH in the configuration grant resource #2. The UE may transmit the configuration grant PUSCH in a section belonging to the COT (eg, symbol(s), uplink symbol(s), flexible symbol(s)) among the configuration grant resource #2. That is, the UE may transmit the PUSCH using only a part of the configuration grant resource #2. In this case, the PUSCH resource mapping may not be changed. In addition, when L or more symbols among the configuration grant resources belong to the COT, the terminal may transmit the configuration grant PUSCH in the configuration grant resource. L may be an integer of 1 or more. For example, L may be 2. Alternatively, when a preset number of REs (eg, a metric corresponding to an RE) of more than a preset number among the configuration grant resources belongs to the COT, the terminal may transmit the configuration grant PUSCH in the configuration grant resource. Alternatively, the UE may not transmit the configuration grant PUSCH in the configuration grant resource #2. As another method, the terminal may transmit the configuration grant PUSCH using the entire configuration grant resource #2.

The above-described method can be applied to a transmission operation of a dynamic grant PUSCH (eg, a PUSCH dynamically scheduled by DCI). When a part of the dynamically scheduled PUSCH resource region belongs to the COT, the UE may or may not transmit the PUSCH based on the above-described method.

In the above-described embodiment, the terminal may receive information indicating whether to transmit the configuration grant PUSCH within the COT, an LBT category, an LBT gap, and the like from the base station. In this case, the UE may transmit the PUSCH using a configuration grant resource (eg, configuration grant resource #2) partially overlapping with the COT based on information received from the base station. This operation may be referred to as “method 150”. For example, the terminal may receive information indicating not to transmit the configuration grant PUSCH in the COT from the base station. In this case, the UE may not transmit the configuration grant PUSCH in not only the configuration grant resource #1 but also the configuration grant resource #2. When starting uplink burst transmission (eg, PUSCH transmission) in the configuration grant resource #2, the terminal may perform an LBT operation immediately before or in the start region of the configuration grant resource #2. In this case, the terminal may perform an LBT operation using an LBT category (eg, first or second category) indicated by the base station, an LBT gap (eg, 16 μs or 25 μs).

Alternatively, the UE may transmit the configuration grant PUSCH according to a predefined rule in the configuration grant resource partially overlapping with the COT regardless of the indication of the base station. For example, the UE may determine whether to transmit the PUSCH in the configuration grant resource partially overlapping with the COT regardless of the indication of the base station. When starting uplink burst transmission in a configuration grant resource that partially overlaps with the COT, the UE operates LBT according to the fourth category (or third category) immediately before the configuration grant resource or in the start region regardless of the instruction of the base station Can be done.

11 is a conceptual diagram illustrating a second embodiment of a method of transmitting a PUSCH in a configuration grant resource overlapping with a COT.

Referring to FIG. 11, the base station may set a configuration grant resource and a PUCCH resource in slot #n to a terminal. Each of the configuration grant resource and the PUCCH resource may be mapped to one or more interlaces. In this case, the end time of the COT may be in the middle of slot #n. When the COT is the COT initiated by the base station, the terminal may obtain the end time of the COT through signaling from the base station. Some of the configuration grant resources may belong to the COT, and the PUCCH resources may not belong to the COT.

In this case, the UE may transmit the PUSCH in the configuration grant resource according to the above-described method. For example, the UE may transmit the PUSCH only in a section belonging to the COT among the configuration grant resources. In this case, the UE actually transmits the PUCCH resource and PUSCH whether to piggyback the UCI (eg, HARQ-ACK, CSI, SR (scheduling request), etc.) set to be transmitted through the PUCCH to the PUSCH. It can be determined based on the temporal overlap between the sections. This operation may be referred to as “method 160”. In the embodiment illustrated in FIG. 11, the PUCCH resource may not overlap with a period in which the PUSCH is actually transmitted in the time domain (eg, a period until the end of the COT). In this case, the UE may not piggyback UCI to PUSCH. For another example, the terminal may transmit the PUSCH in all of the configuration grant resources. In this case, since the PUCCH resource overlaps the period in which the PUSCH is actually transmitted in the time domain, the UE can piggyback UCI to the PUSCH.

Method 160 can be applied not only to unlicensed band communication but also to licensed band communication. The UE may determine whether to multiplex the PUSCH and the PUCCH based on whether or not the resource region actually transmitted by the UE and the resource region of the PUCCH overlap, rather than the nominal resource region allocated from the base station for PUSCH transmission.

[How to obtain transmission bandwidth]

One bandwidth portion may include a plurality of LBT subbands. In this case, the terminal may need to acquire the transmission bandwidth information of the downlink transmission burst as well as the start time of the downlink transmission burst transmitted by the base station. The transmission bandwidth information is the LBT subband(s) to which the downlink transmission burst transmitted by the base station (e.g., the downlink transmission burst transmitted according to the success of the LBT operation) belongs (e.g., continuous LBT in the frequency domain). Subband(s)). The base station may explicitly or implicitly transmit transmission bandwidth information to the terminal through a physical layer signal and/or channel. For example, the UE may obtain transmission bandwidth information by performing an operation of detecting an initial downlink signal, an operation of obtaining COT indication information, and the like.

The transmission bandwidth information may be transmitted through one or more LBT subbands among LBT subband(s) through which a downlink transmission burst is transmitted. This operation may be referred to as “method 200”. Alternatively, the transmission bandwidth information may be transmitted through all LBT subbands in which a downlink transmission burst is transmitted. This operation may be referred to as “method 210”. Method 200 and method 210 may be performed as follows.

12A is a conceptual diagram illustrating a first embodiment of a method for changing a downlink transmission bandwidth and a method for indicating a transmission bandwidth in a COT initiated by a base station, and FIG. 12B is a downlink transmission bandwidth in a COT initiated by a base station It is a conceptual diagram showing a second embodiment of a method of changing a signal and a method of indicating a transmission bandwidth.

Referring to FIGS. 12A and 12B, two downlink transmission bursts (eg, first and second downlink transmission bursts) may be transmitted within a COT initiated by a base station. The transmission bandwidth of the first downlink transmission burst may be different from the transmission bandwidth of the second downlink transmission burst. The base station can extend the downlink transmission bandwidth by additionally performing an LBT operation in the uplink period and/or the gap period in the COT initiated by the base station.

In the embodiment shown in FIG. 12A, according to the method 200, transmission bandwidth information may be transmitted in some LBT subbands (eg, LBT subband #1). For example, the transmission bandwidth information may be transmitted through a group common PDCCH (e.g., a new DCI format extended based on DCI format 2_0 or DCI format 2_0) in a set of CORESET and/or search space set in LBT subband #1. I can. Here, the search space set may mean "PDCCH search space set". In this case, when a plurality of downlink transmission bursts are transmitted within one COT, the LBT subband(s) through which transmission bandwidth information is transmitted may be the same in the plurality of downlink transmission bursts.

For example, when transmission bandwidth information is obtained through LBT subband #1 in a first downlink transmission burst, the UE expects to obtain transmission bandwidth information through LBT subband #1 in a second downlink transmission burst. I can. On the other hand, transmission bandwidth information may be different in a plurality of downlink transmission bursts. This definition can be applied to other embodiments. In method 200, when transmission bandwidth information is transmitted through some LBT subband(s) of the bandwidth portion, some LBT subband(s) may include the above-described primary LBT subband.

In the embodiment shown in FIG. 12B, according to method 210, transmission bandwidth information can be transmitted through all LBT subbands. In the first downlink transmission burst period, transmission bandwidth information may be transmitted through LBT subband #1. In the second downlink transmission burst period, transmission bandwidth information may be transmitted through LBT subbands #1 and #2. For example, transmission bandwidth information may be implicitly transmitted through a physical layer signal and/or channel, and a physical layer signal and/or channel may be transmitted in all LBT subbands constituting a downlink transmission burst. .

For example, a plurality of sequences (eg, a DM-RS sequence) may be defined, and the base station transmits one sequence (eg, a sequence indicating a transmission bandwidth) among a plurality of sequences to the terminal. Can be transmitted. For another example, the transmission bandwidth information may be transmitted through a group common PDCCH of each LBT subband (eg, a new DCI format extended based on DCI format 2_0 or DCI format 2_0). The UE may not know the LBT subband(s) through which the downlink transmission burst is transmitted. Accordingly, the terminal may perform a signal and/or channel detection/reception operation including transmission bandwidth information in all LBT subband(s) constituting the bandwidth portion. The terminal is configured to receive a downlink transmission burst in the LBT subband(s) (e.g., LBT subband(s) consecutive in the frequency domain) in which a signal and/or a channel including transmission bandwidth information is detected/received. Can be assumed.

The number of sets of LBT subband(s) in which a signal and/or channel including transmission bandwidth information is detected/received (eg, sets of consecutive LBT subband(s) in the frequency domain) is 2 In the above case, the terminal may assume that a downlink transmission burst is received in all of the sets of LBT subband(s). Alternatively, the terminal may assume that a downlink transmission burst is received in one of the sets of LBT subband(s). The UE may determine one set from among the sets of LBT subband(s) based on the priority between the LBT subband(s) and the representative LBT subband(s). The base station may inform the UE of the priority between the LBT subband(s) and the representative LBT subband(s) in advance.

13A is a conceptual diagram showing a third embodiment of a method for changing a downlink transmission bandwidth and a method for indicating a transmission bandwidth in a COT initiated by a base station, and FIG. 13B is a downlink transmission bandwidth in a COT initiated by a base station It is a conceptual diagram showing a fourth embodiment of a method for changing a signal and a method for indicating a transmission bandwidth.

13A and 13B, two downlink transmission bursts (eg, a first and a second downlink transmission burst) may be transmitted within a COT initiated by a base station. The transmission bandwidth of the first downlink transmission burst may be different from the transmission bandwidth of the second downlink transmission burst. The base station can reduce the downlink transmission bandwidth by performing the LBT operation in the uplink period and/or the gap period in the COT initiated by the base station. Alternatively, the base station may reduce the downlink transmission bandwidth regardless of the result of the LBT operation.

In the embodiment shown in FIG. 13A, according to the method 200, transmission bandwidth information may be transmitted in some LBT subbands (eg, LBT subband #1). In the embodiment shown in FIG. 13B, according to "Method 210", transmission bandwidth information may be transmitted through all LBT subbands. In the first downlink transmission burst period, transmission bandwidth information may be transmitted through LBT subbands #1 and #2. In the second downlink transmission burst period, transmission bandwidth information may be transmitted through LBT subband #1.

According to the above-described embodiments, the operation of changing the transmission bandwidth for the same transmission direction (eg, downlink) within the COT is applied between a plurality of transmission bursts (eg, a plurality of downlink transmission bursts). I can. Meanwhile, the transmission bandwidth may be changed even within one transmission burst (eg, one downlink transmission burst). In this case, method 200 and method 210 may be applied within one transmission burst.

14 is a conceptual diagram illustrating a fifth embodiment of a method for changing a downlink transmission bandwidth and a method for indicating a transmission bandwidth in a COT initiated by a base station.

Referring to FIG. 14, one bandwidth portion may include three LBT subbands. The base station may succeed in LBT operation in LBT subbands #2 and #3 immediately before t1 or t1. In this case, the base station can occupy the COT from t1 and can transmit a downlink transmission burst within the COT. In addition, the base station may transmit information indicating that the base station has occupied the COT in LBT subbands #2 and #3 (e.g., DCI, a sequence of a reference signal, a sequence of an initial downlink signal, etc.) to the terminal at t1. . The terminal may receive information indicating that the COT is occupied by the base station, may detect a downlink transmission burst in LBT subbands #2 and #3, and may perform a PDCCH monitoring operation.

Here, a guard band may be inserted between the LBT subband #2 and the LBT subband #3. The guard band may be a frequency gap through which signals are not transmitted. The guard band may be maintained for a preset time period. For example, the preset time interval may be ΔT, which is from the start point t1 of the COT to t2. The guard band can be used for data transmission after t2. ΔT (or t2) may be predefined in the technical standard. Alternatively, the base station may set ΔT (or t2) to the terminal. ΔT (or t2) may vary depending on the success point of the LBT operation performed by the base station (eg, the start point of the COT). For example, t2 may be defined (or set) as a K-th slot boundary in the COT. K can be a natural number. ΔT when the LBT operation is successful in the front region of the slot may be different from ΔT when the LBT operation is successful in the rear region of the slot.

The UE may not be able to detect the downlink transmission burst in some LBT subband(s) constituting the COT at the time when the base station initiates the COT or transmits information indicating that the COT has been initiated. In the embodiment shown in FIG. 14, the UE may not be able to detect a downlink transmission burst in LBT subband #1 of t1. The reason is that the terminal did not detect information indicating that the base station transmitted from the base station occupied the LBT subband #1. Alternatively, even though the base station occupies the LBT subband #1, the base station may not intentionally transmit information indicating that the LBT subband #1 is occupied to the terminal. In this case, the terminal may not be able to detect information indicating that the base station has occupied the LBT subband #1.

The base station may transmit information indicating that the base station has occupied the COT in LBT subbands #1 to #3 (eg, DCI, reference signal, downlink initial signal, etc.) to the terminal at time t3. The terminal can confirm that the base station has occupied LBT subbands #1 to #3 by receiving information indicating that the base station has occupied the COT. Accordingly, the UE can expect to receive a downlink transmission burst from not only LBT subbands #2 and #3 but also LBT subband #1 from t3. From the viewpoint of the operation of the terminal, the transmission bandwidth may be changed within one transmission burst. On the other hand, from the viewpoint of operation of the base station, it may be difficult to change the transmission bandwidth within one transmission burst due to a half duplex limitation, characteristics of LBT operation, and frequency regulation conditions. Therefore, in order to transmit the downlink signal and/or channel through the LBT subband #1 from t3, the base station may have to transmit the downlink signal and/or channel through the LBT subband #1 in the period from t1 to t3. have.

In the embodiment shown in FIG. 14, transmission bandwidth information may be transmitted at any LBT subband and/or at any time point. The base station may transmit transmission bandwidth information to the terminal in LBT subbands #2 and #3 of t1. The transmission bandwidth information transmitted in each of LBT subbands #2 and #3 may include information indicating whether the corresponding LBT subband is occupied. In this case, the UE may have to receive transmission bandwidth information in both LBT subbands #2 and #3 in order to check whether LBT subbands #2 and #3 are occupied. Alternatively, the transmission bandwidth information transmitted in each LBT subband may include information indicating whether a plurality of LBT subbands are occupied. In this case, the same transmission bandwidth information may be transmitted through a plurality of LBT subbands. Accordingly, the UE may receive transmission bandwidth information in one LBT subband of LBT subbands #2 and #3 in order to check whether LBT subbands #2 and #3 are occupied.

On the other hand, transmission bandwidth information transmitted in a plurality of LBT subbands may be set independently of each other. For example, transmission bandwidth information transmitted in a plurality of LBT subbands may be the same. Alternatively, transmission bandwidth information transmitted in a plurality of LBT subbands may be different. In this case, the UE can receive all transmission bandwidth information in LBT subbands #2 and #3 to check whether LBT subbands #2 and #3 are occupied, and a plurality of transmission bandwidth information according to a predefined rule (For example, transmission bandwidth information received in LBT subbands #2 and #3) can be analyzed to determine the set of LBT subbands occupied by the base station. That is, the terminal may perform a reception operation (eg, a monitoring operation) in all LBT subbands configured to receive (eg, monitor) transmission bandwidth information.

For example, the transmission bandwidth information may be a bitmap, and each bit of the bitmap may correspond to each LBT subband. The length of the bitmap may be the number of LBT subbands. A bit set to 1 in the bitmap may indicate that the corresponding LBT subband is occupied, and a bit set to 0 in the bitmap may indicate that the corresponding LBT subband is not occupied. Alternatively, a bit set to 1 in the bitmap may indicate that the corresponding LBT subband is not occupied, and a bit set to 0 in the bitmap may indicate that the corresponding LBT subband is occupied. In this case, bitmaps transmitted in the plurality of LBT subbands may have the same length and different bit sequences.

In order to determine whether the LBT subband is occupied, the UE applies an operation (e.g., bit operation) according to a predefined rule to the bit(s) corresponding to the LBT subband obtained from one or more bitmaps. In addition, it is possible to determine whether the LBT subband is occupied based on the result of the operation. For example, if the result of the operation is 1, the terminal may determine that the base station occupies the corresponding LBT subband. That is, the terminal may assume that the base station transmits a downlink transmission burst in the corresponding LBT subband.

The signal and/or channel including the transmission bandwidth information may further include other information. For example, other information includes slot format information of the slot(s) constituting the COT, setting information of the COT, information indicating whether to share the COT, information indicating whether or not to allow PUSCH transmission in the setting grant resource in the COT, etc. It may include. The COT setting information may include a start point, an end point, and a length (or duration) of the COT.

When one bandwidth portion includes a plurality of LBT subbands, the base station may obtain information on a start time point of an uplink transmission burst, information on a transmission bandwidth, and the like from the terminal. The start time information and transmission bandwidth information of the uplink transmission burst may be transmitted from the terminal to the base station through uplink control information (UCI). UCI can be transmitted through PUCCH. Alternatively, the UCI may be transmitted by piggybacking on the PUSCH. UCI may be transmitted through the start region of an uplink transmission burst. The start region of the uplink transmission burst may be one or more symbols among symbol(s) from the first symbol to the Y-th symbol. Here, Y may be a natural number.

Alternatively, information on the start time and transmission bandwidth of the uplink transmission burst may be implicitly transmitted through a physical layer signal and/or a channel. For example, a plurality of sequences (e.g., an uplink DM-RS sequence, an SRS sequence, etc.) may be defined, the terminal may select one sequence from among a plurality of sequences, and the selected sequence to the base station. Can be transmitted. Here, the selected sequence may indicate start time information and transmission bandwidth information of an uplink transmission burst. In this case, the above-described methods (eg, method 200 and method 210) are applied in the same or similar manner to determine the LBT subband(s) in which the information on the start time of the uplink transmission burst and the transmission bandwidth information are transmitted. I can.

Method 200 and method 210 may be applied simultaneously for one COT or one transmission burst. Two time intervals may be defined (or set) within one COT or one transmission burst, and method 200 and method 210 may be applied respectively in the two time intervals. For example, method 210 may be used in the start interval of the COT or transmission burst, and method 200 may be used in the remaining intervals. The start section of the COT or transmission burst may be symbols from the first symbol to the Y-th symbol (eg, Y symbols). Alternatively, the start period of the COT or the transmission burst may be slots (eg, Z slots) from the first slot to the Z-th slot. Z can be a natural number. The Z slot(s) may include partial slots according to the LBT success time. The end point (eg, Y or Z) of the start section of the COT or transmission burst may be predefined in the technical standard. Alternatively, the base station may inform the terminal of the end time information of the start section of the COT or the transmission burst.

For example, when a group common PDCCH (eg, a new DCI format extended based on DCI format 2_0 or DCI format 2_0) is used for transmission of a downlink transmission burst, the terminal The group common PDCCH may be monitored in each LBT subband according to method 210 in the start period. In addition, the UE may monitor the group common PDCCH in one or more LBT subbands according to method 200 in the remaining period. Set information of the LBT subband(s) on which the monitoring operation for the group common PDCCH is performed in the remaining period may be signaled from the base station to the terminal.

The set information of the LBT subband(s) in which the monitoring operation for the group common PDCCH is performed in the remaining period may be dynamically signaled through the group common PDCCH in the start period of the COT or downlink transmission burst. Accordingly, the UE receives the group common PDCCH in the start period of the COT or downlink transmission burst, and thus can check the set of LBT subband(s) in which the monitoring operation for the group common PDCCH is performed in the remaining period. Alternatively, the set information of the LBT subband(s) in which the monitoring operation for the group common PDCCH is performed in the remaining period may be semi-fixedly set by RRC signaling. Set information of the LBT subband(s) in which the monitoring operation for the group common PDCCH is performed in the remaining period may be set by a combination of RRC signaling and DCI.

Meanwhile, the base station may transmit information instructing to receive a signal and/or a channel in a frequency region (eg, an LBT subband) outside the transmission bandwidth of the downlink transmission burst to the terminal. The terminal may receive a signal and/or a channel in a frequency domain outside the transmission bandwidth of the downlink transmission burst based on the corresponding information. Signals and/or channels in a frequency domain (eg, LBT subband) outside the transmission bandwidth of the downlink transmission burst may be PDSCH. Information instructing to receive a signal and/or a channel in a frequency domain outside the transmission bandwidth of the downlink transmission burst may be dynamic indication information (eg, DCI instructing scheduling of a PDSCH) by physical layer signaling. Alternatively, information indicating to receive a signal and/or a channel in a frequency domain outside the transmission bandwidth of the downlink transmission burst may include a dynamic indicator other than the scheduling indicator.

15 is a conceptual diagram illustrating a first embodiment of a method of extending a transmission bandwidth according to a PDSCH scheduling instruction.

Referring to FIG. 15, one bandwidth portion may include two LBT subbands. The UE may detect (or receive) a downlink transmission burst in LBT subband #2 of slot #n, and may perform a PDCCH monitoring operation on the downlink transmission burst. In this case, the UE may receive the PDCCH through the LBT subband #2 of slot #n+2, and may obtain a DCI scheduling the PDSCH from the PDCCH. The PDSCH may be allocated to LBT subband #2 as well as LBT subband #1.

In this case, even though the transmission bandwidth of the COT that the UE expects to receive at the corresponding time (eg, the time scheduled by DCI) does not include the LBT subband #1, the UE follows the DCI scheduling instruction. The PDSCH can be received in bands #1 and #2. The UE transmits a downlink transmission burst from the base station through the LBT subband #1 from the previous time point in slot #n+2 (e.g., slot #n, which is the time when the UE acquires the COT in LBT subband #2). It can be regarded as not being detected. That is, when information instructing to receive a signal and/or a channel in a frequency domain (eg, LBT subband) outside the transmission bandwidth of the downlink transmission burst is received from the base station, the terminal / Or can receive a channel. This operation may be referred to as “method 230”.

Alternatively, the UE may receive a signal and/or a channel only within a transmission bandwidth in which reception of a downlink transmission burst is expected at a corresponding time (eg, a time scheduled by DCI), and the downlink transmission burst A signal and/or a channel may not be received in a frequency domain other than the transmission bandwidth expected to be received. Accordingly, the UE may receive the PDSCH in LBT subband #2 of slot #n+2. In addition, the UE may determine that the PDSCH scheduling instruction according to the DCI received in slot #n+2 is incorrect, and may not receive the PDSCH in LBT subband #1 of slot #n+2.

According to method 230, the UE may consider that LBT subband #1 is occupied by the base station through a PDSCH scheduling instruction from the base station. Accordingly, the UE can expect to receive a downlink transmission burst through the LBT subband #1 in slot(s) after slot #n+2 and slot #n+2 to which the PDSCH is allocated. In the embodiment shown in FIG. 15, the terminal may expect to receive a downlink transmission burst from the base station in the resource region indicated by "A", and may perform a PDCCH monitoring operation for reception of the downlink transmission burst. . Simultaneously or separately, the UE bursts downlink transmission through the LBT subband #1 in the slot(s) prior to slot #n+2 to which the PDSCH is allocated (for example, slot #n and slot #n+1) You can expect to receive The terminal may assume that the time when the base station occupies the LBT subband #1 is the same as the time when the terminal acquires the COT in the LBT subband #2. Alternatively, the UE may assume that the time point of occupancy of the LBT subband #1 of the base station is earlier than the time point at which the UE acquires the COT in the LBT subband #2.

Based on the above assumption, the UE may perform a PDCCH monitoring operation corresponding to the PDCCH monitoring operation in the COT (eg, LBT subband #2) in the LBT subband #1. For example, the UE may perform a PDCCH monitoring operation of a third period to be described later in LBT subband #2 of slot #n+3. In this case, the UE may assume the same period as the third period in LBT subband #1 of slot #n+3, and may perform a PDCCH monitoring operation in LBT subband #1 of slot #n+3. The end time of LBT subband #1 may be the same as the end time of LBT subband #2. The UE may regard the COT end time of the LBT subband extended by the method 230 as the same as the COT end time of the other LBT subbands constituting the same downlink transmission burst. When there are two or more different LBT subbands constituting the same downlink transmission burst, the UE performs a PDCCH monitoring operation in the extended LBT subband based on one LBT subband among two or more LBT subbands. I can.

The UE may assume the same PDCCH monitoring period as the LBT subband #2 in slot #n+2 (e.g., slot #n+2 of LBT subband #1) to which the PDSCH is allocated, and LBT subband #1 PDCCH monitoring operation can be performed in the. On the other hand, as another method, in the LBT subband #1 of slot #n+2, the terminal performs a PDCCH monitoring operation corresponding to the PDCCH monitoring operation performed in the outer region of the COT (e.g., a PDCCH monitoring operation in the first period to be described later) ) Can be performed.

When the transmission bandwidth indicator (e.g., transmission bandwidth information) is received at the time of reception of the resource allocation information of the PDSCH or after the reception time, the terminal indicates that the corresponding transmission bandwidth indicator is extended by dynamic resource allocation LBT subband information ( For example, information indicating that the LBT subband #1 is occupied by the base station) may be expected to be included. Alternatively, if the UE does not match the LBT subband(s) extended by resource allocation of the PDSCH and the LBT subband(s) indicated by the transmission bandwidth indicator, the UE provides the PDSCH resource allocation information and transmission bandwidth. One of the indicators may be considered to be incorrect, and whether to perform a reception operation in LBT subband #1 may be determined based on one of the resource allocation information of the PDSCH and the transmission bandwidth indicator.

In the embodiment shown in FIG. 15, the indicator for scheduling PDSCH in LBT subband #1 of slot #n+2 is LBT subband #2 (eg, LBT subband belonging to the same bandwidth portion as LBT subband #1). Band or LBT subband constituting the same downlink transmission burst as LBT subband #1). Alternatively, the PDSCH scheduling indicator may be transmitted to the terminal through another LBT subband (eg, an LBT subband within a different carrier or a different bandwidth portion).

The resource allocation method outside the transmission bandwidth and the transmission bandwidth extension method according to method 230 may be performed through a cross-carrier scheduling method, a cross-bandwidth partial scheduling method, and the like. Method 230 may be used for a PUSCH transmission operation in an uplink transmission burst interval. For example, the UE is requested to transmit an uplink signal and/or a channel (eg, PUSCH) in a frequency domain (eg, LBT subband) other than the transmission bandwidth of the uplink transmission burst assumed by the UE. You can receive instructing information. In this case, the terminal may transmit an uplink signal and/or channel in the frequency domain according to the indication of the corresponding information. In addition, the terminal may extend the transmission bandwidth of the uplink transmission burst based on the time when the corresponding information is received or the time indicated by the corresponding information, and the uplink signal and/or by using the extended transmission bandwidth within the corresponding COT. Channel can be transmitted.

[PDCCH monitoring operation]

The initial downlink signal may be used for the detection operation of the downlink transmission burst of the terminal. The downlink initial signal may be arranged in the start section of the downlink transmission burst. The UE may monitor the downlink initial signal to detect the downlink transmission burst, and may omit other monitoring operations (eg, PDCCH monitoring operation). The UE may successfully detect a downlink transmission burst through reception of an initial downlink signal. The UE may perform a PDCCH monitoring operation for a preset time (eg, COT or MCOT) from the detection time of the downlink transmission burst. The PDCCH monitoring configuration (or PDCCH monitoring operation) of the UE may be dynamically changed based on the detection time of the downlink transmission burst. Accordingly, the power required for the PDCCH monitoring operation of the terminal can be reduced.

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

In unlicensed band communication, the PDCCH monitoring operation of the terminal may be dynamically changed according to the time interval. The PDCCH monitoring operation may be dynamically changed based on the detection time of the downlink transmission burst of the terminal. The UE may perform a monitoring operation on the downlink initial signal in a period other than the COT (hereinafter referred to as “first period”) initiated (eg, initiated) by the base station. When the downlink initial signal includes the PDCCH (eg, control information included in the PDCCH), the UE may perform a PDCCH monitoring operation for reception of the PDCCH in the first period. On the other hand, when the downlink initial signal does not include the PDCCH, the UE may not perform the PDCCH monitoring operation in the first period. For example, when the downlink initial signal includes the PDCCH DM-RS, the UE may perform a blind detection operation for the PDCCH DM-RS in the first period.

When a downlink transmission burst is detected, the UE starts the first interval from the start interval of the COT (e.g., a preset time interval starting from the first symbol of the COT) started by the downlink transmission burst or the downlink transmission burst. A PDCCH monitoring operation different from the PDCCH monitoring operation performed in may be performed. The second period may be a downlink transmission burst or a start period of a COT corresponding to a downlink transmission burst. The start section of the COT may be the first slot of the COT. The first slot of the COT may be a partial slot. The base station may inform the terminal of the end time information of the second interval through signaling. In this case, the end point of the second interval may be expressed as a relative distance from the start point of the COT or downlink transmission burst. The end point of the second interval may be set in the terminal in a symbol unit or a slot unit granularity.

In the downlink transmission burst or the COT initiated by the downlink transmission burst, the remaining intervals except for the second interval may be defined as the third interval. The third period may be a period from the end of the second period to the end of the COT initiated by the downlink transmission burst or the downlink transmission burst. The UE may not know when the downlink transmission burst or COT ends. In this case, the UE may determine the end time of the third period using the initial detection time of the (first) downlink transmission burst in the COT or the COT and the MCOT. For example, the terminal may regard a time point after the MCOT from the initial detection time of the COT as the end time of the third section. The above-described method may be referred to as “method 300”.

The PDCCH monitoring operation in the COT initiated by the base station (eg, the second and third intervals) may be different from the PDCCH monitoring operation in the first interval. The UE may monitor the PDCCH constituting the downlink initial signal in the second and third intervals, and may also monitor other PDCCHs. This operation may be performed based on the set of CORESET and search spaces set by the base station. In addition, the PDCCH monitoring operation in the second interval may be different from the PDCCH monitoring operation in the third interval. For example, the interval or period of the PDCCH monitoring operation in the second interval may be shorter than the interval or period of the PDCCH monitoring operation in the third interval. The interval or period of the PDCCH monitoring operation in the second period may be set in units of symbols, and the interval or period of the PDCCH monitoring operation in the third period may be set in units of slots.

The base station may independently set the PDCCH monitoring operation to the terminal in each of the second and third intervals. The search space set (s) for the second section may be different from the search space set (s) for the third section. In this case, the search space set (s) for the second and third sections may correspond to the same CORESET. The base station may inform the terminal of information on the search space set setting(s) for the first section through signaling. The search space set setting(s) for the first section may be independent from the search space set setting(s) for the second and third sections. Also, the search space set setting(s) for the first section and the search space set setting(s) for the second section and/or the third section may belong to the same CORESET.

The change of the PDCCH monitoring operation between the second and third intervals may be applied in the USS set. In the case of the CSS set, the UE may perform a PDCCH monitoring operation according to the same setting in the second and third intervals. Alternatively, the change of the PDCCH monitoring operation between the second and third intervals may be applied in both the USS set and the CSS set. One or more search space sets may be set for each of the second and third intervals, and the one or more search space sets may include a USS set and/or a CSS set. Alternatively, the set of search spaces for each of the second section and the third section may include a specific type of CSS set (eg, a type 3 CSS set).

16A is a conceptual diagram showing a first embodiment of a method for dynamically changing a PDCCH monitoring operation, and FIG. 16B is a conceptual diagram showing a second embodiment of a method for dynamically changing a PDCCH monitoring operation.

Referring to FIG. 16A, the PDCCH monitoring operation may be performed in three periods (eg, first, second, and third periods). The definitions of the first section, the second section, and the third section may be the same as those described above, and the PDCCH monitoring operation in the first section, the second section, and the third section may be the same as the above-described operation.

Referring to FIG. 16B, a plurality of downlink transmission bursts (eg, first and second downlink transmission bursts) may be transmitted within one COT initiated by the base station. An uplink transmission burst may be transmitted between the first downlink transmission burst and the second downlink transmission burst. In this case, the PDCCH monitoring operation of the UE may be performed in three periods (eg, the first, second, and third periods). The definitions of the first section, the second section, and the third section may be the same as those described above, and the PDCCH monitoring operation in the first section, the second section, and the third section may be the same as the above-described operation.

For example, the terminal knowing the end point of the COT may determine that the third section is a section from the second slot of the COT to the end point of the COT. The first section, the second section, and the third section according to the method 300 may be defined based on a COT instead of a downlink transmission burst. In this case, the section occupied by the downlink transmission burst may be included in the third section, and the uplink transmission burst and/or gap section (eg, some sections of slot #n+2) are excluded from the third section. Can be. Alternatively, the third period may include a downlink transmission burst, an uplink transmission burst, and/or a gap period.

When the above-described method is applied, the start time of the remaining downlink transmission burst(s) except for the first downlink transmission burst within one COT may be limited. In addition, the end time of the uplink transmission burst(s) within the same COT may be limited. For example, the remaining downlink transmission burst(s) may start at a slot boundary (eg, the first symbol of a slot).

For another example, the remaining downlink transmission burst(s) may start at the first symbol of a specific PDCCH monitoring occasion in the third period. Alternatively, the end time of the uplink transmission burst(s) (or idle period(s)) to satisfy the above-described condition is a specific symbol (eg, the last symbol) of the slot or a specific PDCCH monitoring occasion in the third period May be limited to the previous symbol of the first symbol of. Alternatively, in order to secure a time required for the LBT operation of the base station, the end time of the uplink transmission burst(s) (or idle period(s)) may be limited to a preset gap before the above-described time point. In the embodiment shown in FIG. 16, the second downlink transmission burst may satisfy both conditions described above.

Meanwhile, in the COT initiated by the base station, the uplink transmission burst may be arranged in an arbitrary interval. In this case, the downlink transmission burst(s) after the uplink transmission burst may start at any time. This operation will be described in the examples below.

FIG. 17A is a conceptual diagram showing a third embodiment of a method for dynamically changing a PDCCH monitoring operation, and FIG. 17B is a conceptual diagram showing a fourth embodiment of a method for dynamically changing a PDCCH monitoring operation.

17A and 17B, the first and second downlink transmission bursts may be transmitted within the COT initiated by the base station, and an uplink transmission burst between the first downlink transmission burst and the second downlink transmission burst. Can be transmitted. In this case, the second downlink transmission burst may start from the middle of slot #n+2. Based on the above-described method, if the interval in which the second downlink transmission burst is transmitted in slot #n+2 is regarded as the third interval, the terminal may not perform the PDCCH monitoring operation in the start interval of the second downlink transmission burst. have. Accordingly, the UE may not receive the PDCCH and/or the PDSCH according to the PDCCH in the start period of the second downlink transmission burst.

In order to solve the above-described problem, the UE may perform a PDCCH monitoring operation different from the PDCCH monitoring operation of the third period in the start period of the remaining downlink transmission burst(s). The start period of the downlink transmission burst may be the first slot of the downlink transmission burst. The first slot may be a partial slot. For example, in the embodiment shown in FIG. 17A, the start section of the second downlink transmission burst may be regarded as the second section, and the terminal is defined for the second section in the start section of the second downlink transmission burst. It is possible to perform the PDCCH monitoring operation. Method 300 may be applied to each downlink transmission burst, and the second and third intervals may be defined for each downlink transmission burst. In this case, one of the second and third intervals may exist according to the start time and length of the downlink transmission burst. The start period of the downlink transmission burst may be a part of slot #n+2. For example, the start period of the downlink transmission burst may be a period from the end of the uplink transmission burst or the gap period after the uplink transmission burst to the last symbol of slot #n+2.

For another example, in the embodiment shown in FIG. 17B, the PDCCH monitoring operation in the start period of the second downlink transmission burst may be separately defined. The start period of the second downlink transmission burst may be defined as a fourth period. The base station may set the search space set(s) for the PDCCH monitoring operation of the fourth period in the terminal. Alternatively, one or more PDCCH monitoring occasions in the fourth period may be determined by an implicit method. For example, the UE may perform a PDCCH monitoring operation on symbols from the first symbol to the X-th symbol (eg, X symbol(s)) of the fourth period. The UE may assume that the PDCCH monitoring occasion is set in X symbol(s) within the fourth interval. X may mean the number of symbols of CORESET corresponding to the PDCCH monitoring occasion or search space set. X can be a natural number. For example, X can be 1. The PDCCH setting for the PDCCH monitoring operation of the fourth period may share the CORESET setting associated with the PDCCH setting of the other period described above. In addition, the PDCCH setting of the fourth period (eg, part of the discovery space set setting (eg, CCE aggregation level, the number of PDCCH candidates, etc.)) is the same as the PDCCH setting (eg, discovery space set setting) of the other period. can do.

The UE may determine the start time of the remaining downlink transmission burst(s) based on the end time of the uplink transmission burst(s) transmitted by the UE. A specific terminal may not be able to receive information indicating to transmit an uplink transmission burst in the COT from the base station. In this case, the UE may not know whether there is a downlink transmission burst(s) after the uplink transmission burst or the start time. Accordingly, the UE may assume one second period within the COT as in the embodiment illustrated in FIG. 16A and may perform a PDCCH monitoring operation in the second period. Alternatively, the terminal may assume one fourth period within the COT as in the embodiment shown in FIG. 16B, and may perform a PDCCH monitoring operation in the fourth period. The above-described method may be applied differently for each terminal within one serving cell or base station.

In the above-described embodiments, an interval between the first downlink transmission burst and the second downlink transmission burst may be used as an idle interval instead of an uplink interval. In general, a section between adjacent downlink transmission bursts within one COT may be used as an uplink section and/or a pause section. In addition, the interval between downlink transmission bursts may additionally include a gap for LBT operation. The above-described methods can be applied in any case.

A terminal operating in an RRC connected state may perform the above-described method. In addition, a terminal performing unicast transmission based on a physical layer ID (eg, C-RNTI, MCS-C-RNTI, CS-RNTI) allocated by the base station may perform the above-described method. A terminal operating in the RRC idle state may perform a PDCCH monitoring operation in the CSS set(s) and may not perform a PDCCH monitoring operation in the USS set. The CSS set(s) may include type 0, 0A, 1, and 2 CSS sets. The CSS set(s) may be configured in the terminal through PBCH, MIB, SIB1, or the like. The PDCCH monitoring period in the CSS set may be longer than the PDCCH monitoring period in the USS set. Therefore, the terminal operating in the RRC idle state or the RRC inactive state may not perform the detection operation of the COT or downlink transmission burst, and the PDCCH and the PDCCH and PDSCH can be received.

Meanwhile, due to the uncertainty of the LBT operation, the time required for the random access procedure in the unlicensed band may be longer than the time required for the random access in the licensed band. Therefore, a long time delay may occur for transition from the RRC idle state to the RRC connected state in the unlicensed band. In addition, a terminal without transmission traffic may camp on a serving cell in an RRC idle state. Accordingly, the terminal operating in the RRC idle state may perform a downlink transmission burst detection operation to reduce power consumption.

The terminal operating in the RRC idle state may perform a downlink initial signal monitoring operation in the first period. To this end, the base station may transmit information related to transmission or monitoring of an initial downlink signal to the terminal in a broadcast manner. Information related to transmission or monitoring of the initial downlink signal may be transmitted to the terminal by cell-specific signaling. For example, the setting information of the CORESET and/or the search space set included in the SIB1 or the cell-specific RRC parameter may be used as a downlink initial signal. The base station may signal the SIB1 or cell-specific RRC parameter(s) to the terminal. The setting information of the CORESET and/or search space set may be included in the RRC parameters “PDCCH-ConfigSIB1” and/or “PDCCH-ConfigCommon”. For example, the PDCCH DM-RS for demodulation of DCI format 2_0 and DCI format 2_0 may be used as a downlink initial signal. In this case, the setting information of the CORESET and/or the search space set may include additional CORESET setting information for the type 3 PDCCH CSS set and the type 3 PDCCH CSS set. The type 3 PDCCH CSS set configuration for the terminal operating in the RRC idle state may be limited to be mutually coupled to CORESET #0.

After detecting the downlink transmission burst, the UE operating in the RRC idle state may perform the PDCCH monitoring operation in the CSS set(s) according to the settings of the base station without distinction between the second and third intervals within the corresponding COT. The UE can switch from the current section to the first section after the MCOT from the acquisition time of the COT, and can perform a PDCCH monitoring operation in the first section. Alternatively, the terminal may perform a PDCCH monitoring operation according to the settings of the base station within the MCOT, and may switch from the current period to the first period after the PDCCH monitoring operation is completed. The terminal may switch in advance from the current period to the first period from the time when the COT is acquired before the MCOT.

In the above-described embodiments, the first section may not be distinguished from the second section. The terminal may perform the same PDCCH monitoring operation in the first period and the second period. The base station may signal the configuration information of a common CORESET and/or search space set to the terminal for the PDCCH monitoring operation of the first and second intervals. In this case, the “first section” described in the above-described embodiments may be interpreted as “the second section”. The terminal may perform the PDCCH monitoring operation in the second and third intervals without the first interval. Also, the second period and the third period may not belong to the COT or the transmission burst. The second section and the third section may include sections other than the COT or the transmission burst.

The base station may set one or more sets of search spaces in the terminal for each of the second interval and the third interval. The search space set for the second interval may be referred to as a "second PDCCH group", and the search space set for the third interval may be referred to as a "third PDCCH group". The UE may perform a PDCCH monitoring operation for the second PDCCH group in the second interval, and may perform a PDCCH monitoring operation for the third PDCCH group in the third interval. In addition, the UE may perform a PDCCH monitoring operation on a discovery space set that does not belong to the second PDCCH group in the second period, and performs a PDCCH monitoring operation on a discovery space set that does not belong to the third PDCCH group in the third period. can do.

Switching of the PDCCH monitoring operation between the second PDCCH group and the third PDCCH group may be indicated by an implicit method. For example, a terminal that has successfully received a DCI (or PDCCH) may perform a PDCCH monitoring operation for a third PDCCH group from a slot next to a slot in which a corresponding DCI is received. Alternatively, the terminal that has successfully received the DCI (or PDCCH) is the first slot that appears after the L symbol(s) from the symbol in which the DCI is received (eg, the last symbol or the first symbol in which the DCI is received) PDCCH monitoring for the third PDCCH group may be performed from (eg, a full slot, not a partial slot). L can be a natural number. L may be predefined between the base station and the terminal. Alternatively, the base station may inform the terminal of L.

The DCI (or PDCCH) may be all DCIs (or PDCCHs) that the UE expects to receive. Alternatively, DCI may mean a group common DCI (eg, DCI format 2_0), scheduling DCI (eg, downlink scheduling DCI, scheduling uplink DCI), and the like. The downlink scheduling DCI may be a DCI including scheduling information of the PDSCH. In the NR communication system, the downlink scheduling DCI may include DCI formats 1_0, 1_1, 1_2, and the like. The uplink scheduling DCI may be a DCI including scheduling information of the PUSCH. In the NR communication system, the uplink scheduling DCI may include DCI formats 0_0, 0_1, 0_2, and the like. Simultaneously or separately from the above condition, the DCI indicating switching to the third PDCCH group may be a DCI received through the second PDCCH group (or PDCCH candidate(s) excluding the third PDCCH group). Also, the DCI indicating switching to the second PDCCH group may be a DCI received through the third PDCCH group (or PDCCH candidate(s) excluding the second PDCCH group). The above-described method may be referred to as “method 310”.

Alternatively, the switching procedure of the PDCCH monitoring operation between the second PDCCH group and the third PDCCH group may be performed according to explicit signaling from the base station. For example, the base station may transmit a group common PDCCH (eg, DCI format 2_0) including information indicating switching of the PDCCH monitoring operation to the terminal. The terminal may receive information indicating switching of the PDCCH monitoring operation from the base station. A search space set or PDCCH candidate(s) for monitoring of a group common PDCCH (e.g., DCI format 2_0, or DCI format 2_0 including information indicating switching of a PDCCH monitoring operation) is a symbol(s) of a slot Can also be set. Or, a search space set or PDCCH candidate(s) for monitoring of a group common PDCCH (eg, DCI format 2_0, or DCI format 2_0 including information indicating switching of a PDCCH monitoring operation) is a symbol constituting a slot Among them, it may be set to symbol(s) excluding the last S symbol(s). For example, S may be L. Alternatively, S may be M1 or M2. M1 and M2 will be described later.

A specific field of the group common PDCCH (eg, DCI format 2_0) may include information indicating switching of the PDCCH monitoring operation. For example, when a specific field of the group common PDCCH (eg, DCI format 2_0) is set to “1”, the UE starts from the next slot of the slot in which the group common PDCCH is received or the symbol in which the group common PDCCH is received (eg For example, PDCCH monitoring for the third PDCCH group from the first slot (e.g., a complete slot rather than a partial slot) appearing after M1 symbol(s) from the last symbol or first symbol in which the group common PDCCH is received The operation can be performed. When a specific field of the group common PDCCH is set to "0", the UE starts from the next slot of the slot in which the group common PDCCH is received or the symbol in which the group common PDCCH is received (for example, the last symbol or the first The PDCCH monitoring operation for the second PDCCH group may be performed from a first slot (eg, a complete slot rather than a partial slot) appearing after M2 symbol(s) from the first symbol). M1 and M2 may be natural numbers. In some embodiments, M2 may have the same value as M1. M1 and/or M2 may be predefined between the base station and the terminal. Alternatively, the base station may inform the terminal of M1 and/or M2. In some embodiments, M1 and/or M2 may have a value such as L. The above-described method may be referred to as “method 311”.

According to the above-described method, the PDCCH group can be switched based on a slot boundary. According to the method 311, when a plurality of DCIs are received, the terminal may acquire a plurality of switching indication information for a specific switching time point (eg, a specific slot boundary). For example, when M1=4 or M2=4, the symbols excluding the last 4 symbols of slot #n and/or the switching indication information received in the last 4 symbols of slot #n-1 are slot #n It can be applied from +1. The terminal may receive a plurality of DCIs from the above-described symbols, and may obtain a plurality of switching indication information for slot(s) after slot #n+1 and slot #n+1. In this case, the terminal may expect that all of the plurality of switching indication information for a specific switching point are the same. For example, a plurality of switching indication information may correspond to a specific field set to "1" (eg, a specific field of a group common PDCCH). Alternatively, the plurality of switching indication information may correspond to a specific field set to "0" (eg, a specific field of a group common PDCCH).

Alternatively, a plurality of switching instruction information corresponding to a specific switching point may be set independently of each other. For example, a plurality of switching instruction information corresponding to a specific switching point may be the same. Alternatively, a plurality of switching instruction information corresponding to a specific switching time may be different from each other. In this case, the UE may determine a corresponding switching point and a PDCCH monitoring operation after the corresponding switching point according to specific switching instruction information among a plurality of switching instruction information. For example, the UE may determine whether to switch the PDCCH monitoring operation according to the switching indication information included in the last received DCI. Alternatively, when priority is defined for CORESET, search space set, RNTI, DCI format, etc., through which DCI is transmitted, the UE may determine whether to switch the PDCCH monitoring operation according to the switching indication information included in the DCI having a high priority. have.

For example, if the switching indication information obtained through the group common PDCCH (eg, DCI format 2_0) is different from the switching indication information obtained through the scheduling DCI (eg, downlink scheduling DCI), the terminal is 2 The PDCCH monitoring operation may be performed according to one switching indication information included in a DCI having a high priority among the two switching indication information. For example, the UE may consider that the priority of the scheduling DCI is higher than the priority of the group common PDCCH. For another example, the terminal has a priority of the DCI having the CRC scrambled by the first RNTI (eg, RNTI for URLLC transmission) is scrambled by the second RNTI (eg, RNTI for eMBB transmission) It may be considered to be higher than the priority of the DCI having the CRC, and switching indication information included in the DCI having the CRC scrambled by the first RNTI may be preferentially applied.

The base station may transmit information indicating whether method 310 and/or method 311 is applied to the terminal. For example, information indicating whether method 310 and/or method 311 is applied may be transmitted through RRC signaling. Method 310 and method 311 may be set to be applied simultaneously. In this case, the terminal may receive a plurality of switching indication information indicating a specific switching point. Among the plurality of switching instruction information, one or more switching instruction information may be information obtained by method 310, and the remaining switching instruction information may be information obtained by method 311. When the switching indication information obtained by method 310 is different from the switching indication information obtained by method 311, the terminal may determine whether to switch the PDCCH monitoring operation based on one switching indication information among a plurality of switching indication information. . The priority of the explicitly indicated switching indication information may be considered to be higher than the priority of the implicitly indicated switching indication information. In this case, the terminal may preferentially apply the switching indication information obtained by method 311.

Until "when information instructing switching of the PDCCH monitoring operation is received again from the base station" or "when switching of the PDCCH monitoring operation is performed again according to a specific condition", the terminal may perform the PDCCH monitoring operation determined through the above-described method (eg For example, a PDCCH monitoring operation) may be continuously performed in the second or third period. The PDCCH monitoring operation may be performed in consecutive slots. For example, the terminal is at the end of the COT (e.g., the first slot boundary after the end of the COT, or the first slot boundary appearing after L (or M1, M2) symbols from the last symbol of the COT) A switching operation from the third PDCCH group to the second PDCCH group may be performed based on. The COT end point may be dynamically indicated from the base station to the terminal. The end point of the COT may be indicated through DCI format 2_0.

Alternatively, the COT end time point may be determined as a time point after MCOT from the time point at which the terminal acquires the COT. For another example, the terminal is the time at which the timer expires (e.g., the boundary between the slot at which the timer expires and the next slot, the boundary between the slot and the next slot to which the symbol at which the timer expires, and the symbol at which the timer expires) A switching operation from the third PDCCH group to the second PDCCH group may be performed based on the first slot boundary appearing after (or M1, M2) symbols. The timer may mean a preset time (eg, M slots, N symbols). M and N can be natural numbers. The terminal may obtain information about a timer (eg, the value of the timer) from the base station through a signaling procedure (eg, DCI signaling, RRC signaling). Alternatively, the timer (eg, the value of the timer) may be defined in advance and may be shared between the base station and the terminal.

When it is instructed to switch the PDCCH monitoring operation, the terminal may start a timer. For example, the UE may set a timer to a predefined value or a preset value in a slot in which information indicating switching of the PDCCH monitoring operation is received, and may operate the timer in units of slots. Here, the predefined value or the preset value may be M slots. At the end of each slot, the timer value may decrease by 1. When the value of the timer becomes 0, the timer may expire. In addition, when information instructing to switch the PDCCH monitoring operation is received during the operation of the timer, the terminal may restart the timer.

When method 311 is used, the terminal may start or restart a timer when receiving a group common PDCCH (eg, DCI format 2_0) including information indicating switching of the PDCCH monitoring operation. In this case, the expiration time of the timer may be appropriately controlled by the base station, and the same timer operation may be applied to a plurality of terminals. On the other hand, when method 310 is used, the terminal may start or restart the timer when it successfully receives DCI (or PDCCH). The DCI (or PDCCH) may be any DCI (or PDCCH) that the UE expects to receive. In this case, the timer may be restarted each time the UE receives the PDCCH. Therefore, the timing of expiration of the timer may be difficult to predict. In addition, the operation period of the timer may be different in the terminals.

As a method for solving the above problem, the timer may not be restarted for a certain period of time (hereinafter, referred to as “timer restart prohibition period”) after being started or restarted once. Even when information instructing to switch the PDCCH monitoring operation is received within the timer restart prohibition period, the terminal may not restart the timer. That is, the terminal can maintain the timer operation within the timer restart prohibition period. The timer restart prohibition period may be set in a slot unit (eg, Mp slots) or a symbol unit (eg, Np symbols). Mp may not be greater than M, and Np may not be greater than N. The base station may transmit information on the timer restart prohibition interval to the terminal through a signaling procedure (eg, DCI signaling, RRC signaling), and the terminal may receive information about the timer restart prohibition interval from the base station.

In the PDCCH monitoring period (eg, the second or third period) of the UE, a specific slot may include an uplink period and/or a flexible period. In the PDCCH monitoring period, the PDCCH monitoring operation may be performed in the same manner in the downlink period included in a specific slot. In a specific slot, the UE may omit the blind decoding operation for the PDCCH monitoring occasion belonging to the uplink period and/or flexible period (eg, flexible symbol indicated by SFI), and the downlink period and/or flexible A blind decoding operation for a PDCCH monitoring occasion belonging to a period (eg, a semi-fixed flexible symbol) may be performed.

The switching operation of PDCCH monitoring may be performed within a COT or a transmission burst. Alternatively, the switching operation of PDCCH monitoring may be performed in a period other than the COT or the transmission burst. Meanwhile, in the above-described embodiments, a plurality of downlink transmission bursts may be transmitted within one COT (eg, a COT initiated by a base station). An uplink transmission burst may be transmitted between a plurality of downlink transmission bursts. Alternatively, an idle period may be inserted between a plurality of downlink transmission bursts. Without loss of generality, two downlink transmission bursts (eg, first and second downlink transmission bursts) transmitted within one COT may be considered. It may be assumed that the first downlink transmission burst is transmitted before the second downlink transmission burst.

In this case, the start of the second downlink transmission burst may belong to a specific PDCCH monitoring period. For example, in the embodiment shown in FIG. 16B, the first slot of the second downlink transmission burst may belong to the third period. For another example, in the embodiments shown in FIGS. 17A and 17B, the first slot of the second downlink transmission burst may belong to the second interval or the fourth interval. In the following embodiments, a method for determining the PDCCH monitoring operation in the start period of the second downlink transmission burst will be described. The second downlink transmission burst may be generalized as "a downlink transmission burst occurring after the current downlink transmission burst within the same COT".

As a first method, the above-described method can be applied equally without consideration of a plurality of downlink transmission bursts. The PDCCH monitoring period or the PDCCH set (eg, PDCCH group) of the start slot(s) of the second downlink transmission burst is the switching indication information (eg, trigger information) of the PDCCH generated before the second downlink transmission burst. Can be determined according to. For example, when a PDCCH switching operation is not triggered between a first downlink transmission burst and a second downlink transmission burst, the interval applied to the last slot of the first downlink transmission burst or the PDCCH set is the second downlink transmission. The same can be applied to the start slot(s) of the burst. For another example, when a PDCCH switching operation is triggered once between a first downlink transmission burst and a second downlink transmission burst (e.g., a switching operation from a third PDCCH set to a second PDCCH set by a timer Is triggered), a period or a PDCCH set applied to the start slot(s) of the second downlink transmission burst may follow the triggered PDCCH switching operation.

As a second method, the PDCCH monitoring period or PDCCH set of the start slot(s) of the second downlink transmission burst may always be the same as the PDCCH monitoring period or the PDCCH set of the last slot of the first downlink transmission burst. The above-described timer may be paused in a period between the first downlink transmission burst and the second downlink transmission burst (or a period other than the downlink transmission burst), and the stopped timer is the second downlink transmission burst period. (Or, it may be resumed in the downlink transmission burst period).

As a third method, information on the PDCCH monitoring period or the PDCCH set of the start slot(s) of the second downlink transmission burst may be explicitly signaled from the base station to the terminal. For example, the switching indication information may be included in the uplink scheduling DCI. When the uplink scheduling DCI including switching indication information is received, the UE transmits the PUSCH corresponding to the reception time of the uplink scheduling DCI (eg, a specific symbol of the PDCCH duration) or the uplink scheduling DCI A switching timing of the PDCCH monitoring operation may be determined based on (eg, a specific symbol of the PUSCH duration). Meanwhile, the above-described methods may be applied in the same or similar manner even when a cross-carrier scheduling scheme is used in a plurality of carriers configured/activated in the terminal.

The above-described switching operation of PDCCH monitoring can be applied in common to all LBT subband(s) within one carrier or one bandwidth portion. That is, in all LBT subband(s) constituting one carrier or one bandwidth part, the UE monitors the second PDCCH group and the third PDCCH group at a certain point in time (eg, a certain slot). Any one of the monitoring operations can be performed in common. For example, in all LBT subband(s) constituting one carrier or one bandwidth part, the UE monitors the second PDCCH group and the third PDCCH group at a certain point in time (eg, a certain slot). It can be assumed that any one of the monitoring operations for is performed in common. The instruction of the monitoring operation may be performed by the method described above. The UE may omit the PDCCH monitoring operation in the LBT subband(s) not occupied by the UE itself among the LBT subband(s) or the LBT subband(s) that are assumed not to be occupied by the base station.

In addition, the above-described switching operation of PDCCH monitoring may be commonly applied to a plurality of carriers (or a plurality of bandwidth portions). That is, the UE is one of a monitoring operation for a second PDCCH group and a monitoring operation for a third PDCCH group at a certain point in time (eg, a certain slot) in one or more LBT subband(s) constituting a plurality of carriers. Can be performed in common. For example, the UE is performing a monitoring operation for a second PDCCH group and a monitoring operation for a third PDCCH group at a certain point in time (eg, a certain slot) in one or more LBT subband(s) constituting a plurality of carriers. It can be assumed to perform either one in common.

The instruction of the monitoring operation may be performed by the method described above. The base station may set a set of carrier(s) (or bandwidth part(s)) and/or LBT subband(s) to which the indication of the monitoring operation is applied, and the carrier(s) (or bandwidth part(s)) ) And/or the set of LBT subband(s) may be transmitted to the terminal. The terminal may check a set of carrier(s) (or bandwidth part(s)) and/or LBT subband(s) to which the indication of the monitoring operation is applied based on the configuration information received from the base station. For example, the above-described configuration information may be transmitted to the terminal together with CORESET for the second PDCCH group and/or configuration information of the search space set and CORESET for the third PDCCH group and/or configuration information of the search space set. . For example, the above-described configuration information may include a set of unique index(s) (eg, a carrier indicator field (CIF), a physical layer cell ID, etc.) capable of distinguishing a carrier.

[PDCCH transmission method in frequency domain]

For transmission of downlink control information (eg, DCI), PDCCH candidate(s) may be mapped on a certain time and frequency resource domain (repeated periodically), of which at least one PDCCH candidate(s) PDCCH may be transmitted through. The time and frequency resource regions to which the PDCCH candidate(s) are mapped may be referred to as CORESET, a search space set, and a PDCCH monitoring occasion (hereinafter mainly referred to as CORESET). In addition, the set of PDCCH candidate(s) mapped to the time and frequency resource domain may be referred to as a CORESET, a search space set, and a PDCCH monitoring occasion (hereinafter mainly referred to as CORESET).

CORESET may include one or more PRBs constituting a downlink bandwidth portion. For example, the minimum allocation unit (eg, basic allocation unit) of the frequency resource of CORESET may be six consecutive PRBs. In unlicensed band communication, when one downlink bandwidth portion includes a plurality of LBT subbands (eg, a plurality of RB sets), the LBT operation may succeed in some LBT subband(s). When some or all of the resources of the PDCCH candidate belong to the LBT subband in which the LBT operation has failed, the corresponding PDCCH candidate cannot be used for PDCCH transmission. Therefore, it may be advantageous for each PDCCH candidate to be mapped within one LBT subband.

In order to ensure the above-described operation, the frequency domain of each CORESET may be limited within one LBT subband. CORESET may include one or more PRBs constituting one LBT subband. For example, one downlink bandwidth portion may include two LBT subbands (e.g., LBT subbands #1 and #2), and the base station is in the LBT subband #1, CORESET #1 ( For example, search space set #1, PDCCH candidate #1, PDCCH monitoring occasion #1) can be set, and CORESET #2 (e.g., search space set #2, PDCCH candidate) within LBT subband #2 #2, PDCCH monitoring occasion #2) can be set. Here, the LBT subband may mean an RB set. The base station may inform the terminal of the configuration information of the CORESET (eg, search space set, PDCCH candidate, PDCCH monitoring occasion) set in each of the LBT subvans. The terminal may receive the setting information of the CORESET (e.g., search space, PDCCH candidate, PDCCH monitoring occasion) from the base station, and the CORESET (e.g., search space) set in each of the LBT subbands based on the setting information , PDCCH candidate, PDCCH monitoring occasion) can be identified.

In "when a guard band exists between the LBT subbands" or "when the LBT subband includes a guard band", CORESET may be allocated to a frequency domain excluding the guard band. When the LBT operation is successful in the LBT subband #1, the UE may monitor PDCCH candidates (eg, PDCCH monitoring occasions) of the search space set(s) corresponding to CORESET #1 or CORESET #1. When the LBT operation is successful in the LBT subband #2, the UE may monitor PDCCH candidates (eg, PDCCH monitoring occasions) of the search space set(s) corresponding to CORESET #2 or CORESET #2. Or, regardless of the LBT operation, the terminal monitors the PDCCH candidates (eg, PDCCH monitoring occasions) of the search space set(s) corresponding to CORESET or CORESET in the LBT subband (eg, RB set) can do.

The setting information of the frequency resource of the CORESET (or search space set, PDCCH monitoring occasion) (for example, information of the PRB(s) constituting the CORESET) can be expressed by a bitmap, and the base station is the frequency of the CORESET. A bitmap indicating a resource can be signaled to the terminal. The bitmap may correspond to one or more PRBs constituting the bandwidth portion. For example, each bit of the bitmap may sequentially correspond to six consecutive PRBs. When the maximum number of PRBs included in one carrier is 275, the bitmap may include 46 bits. The number of bits constituting the bitmap may be determined according to "ceil (275/6)". Here, "ceil" may be a ceiling function. For example, when the bandwidth portion is composed of 5 LBT subbands (eg, 5 RB sets), one CORESET (eg, CORESET, search space set, PDCCH monitoring) in each LBT subband 230 bits (eg, 5X46=230 bits) may be required to set the frequency resource of the occasion.

When the above-described method is used, the bitmap may correspond to one or more PRBs constituting each LBT subband. Frequency resources of CORESET (or search space set, PDCCH monitoring occasion) may be allocated based on local PRB indexes in the LBT subband. For example, the first bit of the bitmap may correspond to the 1st to 6th PRBs in the LBT subband, and the second bit of the bitmap may correspond to the 7th to 12th PRBs in the LBT subband. The remaining bits of the bitmap may correspond to PRB(s) in the LBT subband according to the above-described method.

"When a guard band exists between LBT subbands" or "When a guard band exists in the LBT subband", the PRB(s) constituting the guard band is CORESET (or a search space set, PDCCH monitoring occasion) ) May not be set as a frequency resource. For example, when the 1st to 2nd PRBs of the LBT subband are set as the guard band, the first bit of the bitmap may correspond to the 3rd to 8th PRBs of the LBT subband, and the second bit of the bitmap May correspond to 9th to 14th PRBs of the LBT subband. The remaining bits of the bitmap may correspond to PRB(s) in the LBT subband according to the above-described method.

개의 PRB들로 구성될 수 있고, LBT 서브밴드 #i의 첫 번째 PRB(예를 들어, 가장 낮은 인덱스를 가지는 PRB)는 공통 RB 인덱스(예를 들어,

)에 대응될 수 있다. 여기서 i=1, 2, …,

일 수 있고,

는 캐리어 또는 대역폭 부분을 구성하는 LBT 서브밴드들의 개수일 수 있다.CORESET (or search space set, PDCCH monitoring occasion) of UEs in one serving cell may be aligned in the frequency domain by allocating six consecutive RBs as a unit. For example, LBT subband #i of the bandwidth portion is continuous in the frequency domain.

It may be composed of four PRBs, and the first PRB (eg, the PRB having the lowest index) of the LBT subband #i is a common RB index (eg,

) May correspond. Where i=1, 2,… ,

Can be,

May be the number of LBT subbands constituting the carrier or bandwidth portion.

/6)"에 대응될 수 있다. PRB들(예를 들어, 비트맵에 의해 지시되는 PRB들)은 보호 대역을 구성하는 PRB(들)을 포함할 수 있다. LBT 서브밴드가 보호 대역(예를 들어, 보호 대역을 구성하는 PRB(들))을 포함하는 경우, LBT 서브밴드를 구성하는 PRB(들) 중에서 보호 PRB(들)를 제외한 PRB(들) 중에서 첫 번째 PRB(예를 들어, 가장 낮은 인덱스를 가지는 PRB)는 상술한 공통 RB 인덱스

에 대응될 수 있다. 보호 PRB(들)는 보호 대역을 구성하는 PRB(들)을 의미할 수 있다.In this case, among 6 consecutive PRBs corresponding to the first bit of the bitmap, the first PRB has a common RB index "6×ceil(

/6)". PRBs (eg, PRBs indicated by a bitmap) may include PRB(s) constituting a guard band. The LBT subband is a guard band (eg, PRBs indicated by a bitmap). For example, in the case of including the PRB(s) constituting the guard band), the first PRB (eg, the first PRB(s) excluding the protected PRB(s)) among the PRB(s) constituting the LBT subband PRB having a low index) is the common RB index described above

Can correspond to The guard PRB(s) may mean PRB(s) constituting the guard band.

When the above-described method is used, the base station may signal the index (or number) of the LBT subband to the terminal to indicate the LBT subband to which the CORESET (or search space set, PDCCH monitoring occasion) belongs. The index (or number) of the LBT subband may be included in CORESET setting information (eg, frequency domain resource allocation information). The size of the LBT subband (eg, the number of PRBs constituting the LBT subband) may be different for each LBT subband. On the other hand, the length of the bitmap for setting the frequency domain resource of CORESET (or search space set, PDCCH monitoring occasion) may be fixed. In this case, the length of the bitmap may be defined based on the maximum size of the LBT subband (eg, the maximum number of PRBs included in the LBT subband). In the frequency domain, the setting unit of CORESET (or search space set, PDCCH monitoring occasion) may be X consecutive RBs. X may be an integer of 1 or more.

According to the above-described method of signaling a bitmap for each LBT subband, signaling overhead can be reduced. For example, if the bandwidth portion is composed of 5 LBT subbands and each LBT subband is composed of 55 PRBs, the length of the bitmap for allocating one CORESET is 10 bits (for example, ceil(55/6)=10 bits). Therefore, 50 bits (eg, 5=50 bits) may be required to set one CORESET per LBT subband. In this case, the signaling overhead can be reduced by four or more times compared to the above-described signaling method of the bitmap for each bandwidth portion.

In the above-described method, setting parameters necessary for operation in CORESET (or search space set, PDCCH monitoring occasion) may be independently set for each CORESET (or search space set, PDCCH monitoring occasion). In this case, the terminal may need to have a high level of reception capability or capability to monitor a large number of CORESETs. However, in consideration of the implementation complexity and cost of the terminal modem, it may be desirable to design so that the PDCCH reception capability of the terminal is not significantly burdened.

In order to achieve the above object, a plurality of CORESETs (or search space sets, PDCCH monitoring occasions) may share the same setting parameter(s). For example, a specific setting parameter is the same value (e.g., a numerical value, not expressed as a number) for a plurality of CORESETs (or search space sets, PDCCH monitoring occasions) non-numerical) value) or the same level. The plurality of CORESETs may be CORESETs set in one downlink bandwidth portion. The plurality of CORESETs may be CORESETs belonging to different LBT subbands.

For example, the setting parameter(s) for CORESET #1 (e.g., search space set #1, PDCCH candidate #1, PDCCH monitoring occasion #1) is CORESET #2 (e.g., search space set # 2, PDCCH candidate #2, PDCCH monitoring occasion #2) may be set the same as the configuration parameter (s). The base station may transmit the setting parameter(s) for CORESET #1 and/or #2 to the terminal. The setting parameter(s) is the duration of the CORESET (eg, the number of symbols constituting CORESET), the CCE-REG mapping type, information indicating whether to apply interleaving in the CCE-REG mapping operation, and the size of the REG bundle. , Information related to interleaving rules, shift index, precoder granularity, transmission configuration information (TCI) state for PDCCH, information indicating the presence of a DCI field for indicating the TCI state of the PDSCH , And the scrambling ID of the PDCCH DM-RS. For example, when the same TCI state parameter is shared in CORESET #1 and CORESET #2, the UE has a QCL (quasi-co-location) relationship between the PDCCH DM-RS of CORESET #1 and the PDCCH DM-RS of CORESET #2. Can be assumed to be established. Accordingly, the terminal may perform a channel estimation operation or a reception beam setting operation for PDCCH reception based on the QCL relationship.

In order to effectively signal the above-described setting parameter(s), a CORESET group may be defined. CORESETs that share the same setting parameter(s) may belong to the same CORESET group. Here, CORESETs belonging to the same CORESET group may mean search spaces or PDCCH monitoring occasions. The base station may signal one or more of the configuration information for the CORESET operation to the terminal in units of a CORESET group. Even when a plurality of CORESETs belong to the same CORESET group, frequency resources of a plurality of CORESETs (eg, a plurality of search spaces or a plurality of PDCCH monitoring occasions) may be independently set. A plurality of CORESETs (eg, a plurality of CORESETs belonging to the same CORESET group) may share the same search space set(s). The search space set shared by the plurality of CORESETs (eg, the ID of the search space set) may be logically combined with the IDs of the plurality of CORESETs or the ID of the CORESET group to which the plurality of CORESETs belong. Accordingly, the UE may perform a PDCCH monitoring operation on a search space set in each of a plurality of CORESETs (eg, a plurality of subbands). That is, the UE may monitor PDCCH candidates set for the search space set in each CORESET (eg, each subband).

CORESET #2 can be referenced for setting of CORESET #1, and specific setting parameter(s) of CORESET #2 can be used equally for setting of CORESET #1. In a method of referencing another CORESET (eg, CORESET #2) for setting a specific CORESET (eg, CORESET #1), the referenced CORESET setting parameter(s) may include the ID of the CORESET. For example, the referenced CORESET setting parameter(s) may be parameter(s) excluding parameter(s) for setting a frequency domain resource. According to this method, a plurality of CORESETs (eg, CORESET #1 and #2) may be grouped, and the grouped plurality of CORESETs may share the setting parameter(s). This method may correspond to a signaling method for implementing a method of setting a CORESET in units of a CORESET group. The RRC signaling procedure can be used to set the CORESET in units of the CORESET group.

Meanwhile, when the search space set is mutually combined with one or more CORESETs, the PDCCH candidate and the CCE mapping rule may be defined in consideration of the coupling relationship between the search space set and the CORESET(s).

In consideration of the PDCCH reception complexity of the UE, the number of PDCCH candidates that the UE monitors in one slot in one serving cell may be limited. In the case where the subcarrier interval is μ in the NR communication system, the maximum number of PDCCH candidates monitored in each serving cell and/or each slot may be defined as M ^{max, slot, μ} . In this case, M ^max,slot,μ can be defined as shown in Table 2 below.

μ can be an integer. When μ is 0, the subcarrier spacing may be 15 kHz. When μ is 1, the subcarrier spacing may be 30 kHz. When μ is 2, the subcarrier spacing may be 60 kHz. When μ is 3, the subcarrier spacing may be 120 kHz. For example, when the subcarrier interval is 30 kHz, the maximum number of PDCCH candidates monitored by the UE in one slot may be 36. In addition, the number of CCEs that the UE receives for PDCCH monitoring in one slot in one serving cell may be limited. In the case where the subcarrier interval is μ in the NR communication system, the maximum number of CCEs received in each serving cell and/or each slot may be defined as C ^{max,slot, μ} . In this case, C ^max,slot,μ can be defined as shown in Table 2. The number of CCEs may be “the number of CCEs subject to the PDCCH blind decoding operation” or “the number of CCEs subject to the channel estimation operation for PDCCH blind decoding”.

In this case, overlapping PDCCH candidates may not be included in the number of PDCCH candidates according to Table 2, and overlapping CCEs may not be included in the number of CCEs according to Table 2. PDCCH candidates #1 and #2 belonging to different search space sets may be composed of at least the same CCEs, and the same scrambling operation may be applied to DCI formats transmitted through PDCCH candidates #1 and #2, and the corresponding DCI The size of the payload of the formats may be the same. The UE may perform the blind decoding operation of PDCCH candidates #1 and #2 only once. In this case, the UE may regard PDCCH candidates #1 and #2 as overlapping PDCCH candidates. In addition, a condition in which the same QCL is set as well as a redundancy condition of PDCCH candidates may be considered. The QCL may be limited to the above-described spatial QCL (eg, QCL-TypeD), and the configuration parameter for QCL may include other QCL parameter(s).

When CCE #1 and #2 are configured with the same time and frequency resources (for example, the same REGs), the UE performs a reception signal processing operation or a channel estimation operation for CCE #1 and #2 only once can do. In this case, the UE may regard CCEs #1 and #2 as CCEs overlapping each other. When CCE #1 and #2 are configured with the same resources, start symbols to which PDCCH candidates corresponding to different CORESETs are mapped may be different. In this case, the UE may consider that CCE #1 does not overlap with CCE #2. PDCCH candidates associated with overlapping CCEs may have the same QCL configuration, the same DMRS configuration (eg, DMRS pattern, port number, number of ports, etc.).

The base station may set PDCCH candidates exceeding M ^{max,slot, μ} in a specific time period (eg, one slot) of a specific serving cell ^, and may transmit configuration information of PDCCH candidates to the terminal. The terminal may receive configuration information of PDCCH candidates from the base station. Alternatively, the base station may set CCEs exceeding C ^max,slot,μ in a specific time period (eg, one slot) of a specific serving cell ^, and may transmit configuration information of CCEs to the terminal. The terminal may receive configuration information of CCEs from the base station.

Overbooking the PDCCH candidate may not be allowed in the CSS set or may be allowed in the USS set. In addition, when the carrier aggregation scheme is used, setting more than the PDCCH candidate may not be allowed in the secondary cell of the terminal. In this case, the secondary cell may be limited to a secondary cell to which the self-scheduling scheme is applied. Depending on the blind decoding capability of the terminal and the number of downlink carriers set by the base station, each of the maximum number of PDCCH candidates and the maximum number of CCEs in a specific cell (eg, secondary cell) is M ^{max,slot ,μ} and C can be less than ^max,slot,μ .

When the number of PDCCH candidates configured in a specific slot in a specific serving cell exceeds M ^{max,slot, μ} , the UE may not perform a monitoring operation for some PDCCH candidates. That is, the PDCCH candidate may be dropped. The specific serving cell may be a primary cell. The drop operation of the PDCCH candidate may be performed in units of a search space set. Each of the search space sets may be sequentially mapped within a range in which the number of PDCCH candidates monitored by the terminal in the ^slot does not exceed the maximum number (eg, M ^{max,slot, μ} ).

In this case, the UE may monitor all PDCCH candidates of the mapped discovery space set, and may not monitor any PDCCH candidates of the unmapped discovery space set. In addition, when setting more than the PDCCH candidate is allowed only in the USS set, the UE can basically monitor all of the PDCCH candidates of the CSS set in every slot, and some PDCCH candidates having a high priority among the PDCCH candidates of the USS set ( S) can be monitored. In this case, the mapping order (eg, priority) of the USS set may be determined based on the search space set ID. For example, the terminal may map the USS set in the order of the lowest search space set ID.

For example, the downlink bandwidth portion activated in the primary cell of the terminal includes a CSS set with ID=0 (eg, a type 0 PDCCH CSS set), a USS set with ID=1, and a USS set with ID=2. It may include, and each of the search space sets may have PDCCH candidates that do not overlap with each other in a specific slot. For example, a CSS set with ID=0 may have 7 PDCCH candidates, a USS set with ID=1 may have 30 PDCCH candidates, and a USS set with ID=2 may have 50 PDCCH candidates. have. When the subcarrier spacing is 15 kHz in the activated downlink bandwidth portion, M ^{max, slot, μ} may be 44 according to the above-described rule. Accordingly, the UE may first map 7 PDCCH candidates belonging to the CSS set with ID=0 in the corresponding slot, and then map 30 PDCCH candidates belonging to the USS set with ID=1. When the USS set with ID=2 is additionally mapped, the number of mapped PDCCH candidates may exceed M ^max,slot,μ (ie, 44). Accordingly, the UE may not map the USS set with ID=2 and may not monitor the PDCCH candidate belonging to the USS set with ID=2.

For another example, a CSS set with ID=0 in a specific slot may include 7 PDCCH candidates, a USS set with ID=1 may have 50 PDCCH candidates, and a USS set with ID=2 may include 30 Can have PDCCH candidates. Here, each of the search space sets may have PDCCH candidates that do not overlap each other in a specific slot. According to the above-described rule, the UE may first map 7 PDCCH candidates belonging to the CSS set with ID=0 in the corresponding slot. When the USS set with ID=1 is additionally mapped, the number of mapped PDCCH candidates may exceed M ^max,slot,μ (ie, 44). Accordingly, the UE may not map the USS set with ID=1 and may not monitor the PDCCH candidate belonging to the USS set with ID=1. In addition, the UE may not map the USS set with ID=2 and may not monitor the PDCCH candidate belonging to the USS set with ID=2.

The number of CCEs may be limited in the sequential mapping procedure of the search space set and the PDCCH candidate. The UE may sequentially map the search space set and the PDCCH candidates for the search space set to satisfy the following conditions in a specific slot.

-The number of PDCCH candidates monitored by the terminal ≤ M ^max,slot,μ

-The number of CCEs (eg, CCEs associated with mapped PDCCH candidates) ≤ C ^{max,slot, μ}

Meanwhile, a specific USS set may be combined with a plurality of CORESETs. A plurality of CORESETs mutually combined with a specific USS set may be set in different LBT subbands within the same bandwidth portion. For example, the downlink bandwidth portion activated in the serving cell may include 4 LBT subbands (eg, LBT subbands #1 to #4), and a CSS set with ID=0 and ID=1 It may contain a USS set. The CSS set with ID=0 may include 7 PDCCH candidates in a specific slot, and the USS set with ID=1 may include 10 PDCCH candidates in a specific slot. Search space sets may have PDCCH candidates that do not overlap with each other.

In this case, the CSS set with ID = 0 may be mutually combined with the CORESET set in the LBT subband #1, and the USS set with ID = 1 has four CORESETs set in each of the LBT subbands #1 to #4 (for example, For example, it may be mutually combined with CORESET #1 to #4). In this case, the USS set with ID=1 may have 10 PDCCH candidates in each CORESET (eg, each LBT subband). Accordingly, the total number of PDCCH candidates configured in the UE in a specific slot may be 47 (eg, 7+4=47). Since 47 PDCCH candidates exceed the UE's capability, the UE can drop all PDCCH candidates belonging to the USS set with ID = 1 in the corresponding slot, and select PDCCH candidates belonging to the USS set with ID = 1 in the bandwidth part. May not be monitored.

Therefore, the PDCCH transmission capacity in the corresponding slot can be reduced. The base station may reduce the number of PDCCH candidates belonging to the USS set to prevent dropping of the USS set. In this case, although transmission may be performed only in some LBT subbands of the bandwidth portion according to the result of the LBT operation, the PDCCH transmission capacity per LBT subband may be unnecessarily limited.

In order to solve the above-described problem, each of the PDCCH candidates and CCEs may be mapped in a subdivided unit than a search space set. For example, when one search space set is mutually coupled to one or more CORESETs or LBT subbands, PDCCH candidates and CCEs may be sequentially mapped from a search space set having a low ID. In this case, when a specific search space set is mutually coupled to one or more CORESETs or LBT subbands, the mapping operation may be sequentially performed in units of CORESET or LBT subbands in the specific search space set. That is, PDCCH candidates and CCEs may be sequentially mapped in units of a combination of a search space set (eg, USS set) and a CORESET (or LBT subband) mutually combined with the search space set.

The USS set with ID=1 may include 10 PDCCH candidates for each of the 4 CORESETs in a specific slot. When the proposed method is applied, 7 PDCCH candidates belonging to a CSS set with ID=0 in a specific slot and CCEs corresponding to the 7 PDCCH candidates may be mapped first. Next, 10 PDCCH candidates for CORESET #1 (or LBT subband #1) belonging to the USS set with ID=1 and CCEs corresponding to the 10 PDCCH candidates may be mapped. Next, 10 PDCCH candidates for CORESET #2 (or LBT subband #2) belonging to the USS set with ID=1 and CCEs corresponding to the 10 PDCCH candidates may be mapped. Next, 10 PDCCH candidates for CORESET #3 (or LBT subband #3) belonging to the USS set with ID=1 and CCEs corresponding to the 10 PDCCH candidates may be mapped.

When 10 PDCCH candidates for CORESET #4 (or LBT subband #4) belonging to the USS set with ID=1 are additionally mapped, the total number of mapped PDCCH candidates exceeds M ^max,slot,μ Therefore, the 10 PDCCH candidates may not be mapped. That is, the UE may perform a monitoring operation of a PDCCH belonging to the USS set with ID=1 in LBT subband #1 to #3, and a monitoring operation of a PDCCH belonging to USS set with ID=1 in LBT subband #4. May not be performed.

In the above-described embodiments, it is assumed that PDCCH candidates are sequentially mapped from CORESET #1 to CORESET #4 in the USS set. The mapping order of the CORESET or LBT subbands in the search space set may be determined by another method. For example, PDCCH candidates may be mapped in an ascending order of IDs from a CORESET or LBT subband having a low ID in the search space set. Alternatively, the PDCCH candidate may be mapped in descending order of ID from a CORESET or LBT subband having a high ID in the search space set. In the above-described embodiment, the LBT subbands may be LBT subbands occupied according to the LBT operation performed by the base station, and CORESET may be a CORESET corresponding to the LBT subbands occupied by the base station.

On the other hand, for wideband operation in an unlicensed band, it may be allowed for the base station to set PDCCH candidates and CCEs constituting the CSS set to exceed M ^{max, slot, μ} and C ^{max, slot, μ} . In this case, the above-described PDCCH candidate mapping method can be applied equally to the CSS set. In addition, the above-described PDCCH candidate mapping method can also be applied to a secondary cell. M ^max,slot,μ and C ^max,slot,μ may be set to values different from those defined in Table 2. For example, considering a broadband operation in an unlicensed band, M ^{max, slot, μ} and C ^{max, slot, μ} may increase. Alternatively, the reference time interval to which M ^{max, slot, μ} and C ^{max, slot, μ} is applied may be changed. For example, the reference time interval may be defined (or set) as an interval shorter than one slot (eg, Y symbols). Y may be a natural number of 10 or less.

The above-described method may be applied to some CORESET(s) and/or some search space set(s). For example, the above-described method can be applied to other CORESETs except for CORESET #0 (eg, CORESET with ID=0). The above-described CORESET setting method may be performed by an RRC signaling procedure. RRC signaling may include both cell-specific RRC signaling (eg, SIB1, SIB, or other system information (OSI)) and terminal-specific RRC signaling. The above-described CORESET setting method may be applied to CORESET (eg, CORESET #0) set by PBCH and/or MIB. For another example, the above-described method can be applied to all search space sets (eg, Type 0, 0A, 1, and 2 PDCCH CSS sets, and USS set) except for the Type 3 PDCCH CSS set.

In the embodiments below, methods for ensuring that each PDCCH candidate is mapped within one LBT subband will be described.

FIG. 18A is a conceptual diagram showing a first embodiment of a method for setting CORESET and frequency domain resources of a search space set, and FIG. 18B is a conceptual diagram showing a second embodiment of a method for setting CORESET and frequency domain resources of a search space set. to be.

Referring to FIG. 18A, search space set #1 may be mutually combined with CORESET #1. The setting information of the search space set #1 may include the ID of CORESET #1, and the PDCCH may be transmitted from the search space set #1 according to the setting of CORESET #1. For example, the frequency domain resource of search space set #1 may be determined by the frequency domain resource of CORESET #1.

Referring to FIG. 18B, search space sets #1 and #2 may be mutually combined with CORESET #1. In this case, the search space set may include one or more frequency domain occasions. Here, the frequency domain occasion may mean a PDCCH monitoring occasion, a CORESET, a search space set, and a PDCCH candidate(s) that are distinguished in the frequency domain. The frequency domain of each frequency domain occasion may be the same as or different from the CORESET mutually combined with the search space set. For example, the frequency domain of each frequency domain occasion may be the same as the frequency domain of CORESET. Alternatively, the frequency domain of each frequency domain occasion may be a frequency domain in which the frequency domain of CORESET is shifted by a preset frequency offset.

In the embodiment shown in FIG. 18A, CORESET #1 may be disposed in LBT subband #1. Further, the search space set #1 may include two frequency domain occasions (eg, frequency domain occasions #1 and #2). In this case, the frequency domain of the frequency domain occasion #1 may be the same as the frequency domain of CORESET #1. On the other hand, the frequency domain of frequency domain occasion #2 may be different from the frequency domain of CORESET #1. For example, the frequency domain occasion #2 may be disposed in a frequency domain in which the frequency domain of CORESET #1 is shifted by a preset value (Δf). The frequency domain occasion #2 may be disposed in an LBT subband (eg, LBT subband #2) different from CORESET #1 through the shift in the frequency domain. The UE may apply the CORESET and search space set settings in the same manner in each frequency domain occasion, and may perform a PDCCH monitoring operation in each frequency domain occasion. One CORESET and one search space set may be disposed in a plurality of LBT subbands, and PDCCH candidates constituting the search space set may be disposed in one LBT subband.

In the embodiment shown in FIG. 18B, CORESET #1 may be disposed in LBT subband #1. Also, the search space sets #1 and #2 may include one frequency domain occasion (eg, frequency domain occasion #1). The frequency domain of the search space set #1 or the frequency domain occasion #1 of the search space set #1 may be the same as the frequency domain of CORESET #1. The frequency domain occasion #1 of the search space set #2 or the search space set #2 may be arranged in a frequency domain in which the frequency domain of CORESET #1 is shifted by a preset value (Δf).

According to this operation, each of the search space sets #1 and #2 may be disposed in different LBT subbands. This operation can be implemented through a single CORESET. For example, one CORESET may be associated with search space sets (eg, PDCCH monitoring occasions) located in different LBT subbands (eg, RB sets). In the above-described embodiments, CORESET and PDCCH monitoring occasions may be allocated in units of LBT subbands for broadband communication in an unlicensed band. The above-described method can be applied to a portion of a bandwidth in which the LBT subband is not configured. For example, each of the LBT subbands #1 and #2 may be generalized to frequency domains #1 and #2 (eg, PRB sets #1 and #2) in the bandwidth portion.

FIG. 19A is a conceptual diagram showing a third embodiment of a method for setting CORESET and frequency domain resources of a search space set, and FIG. 19B is a conceptual diagram showing a fourth embodiment of a method for setting CORESET and frequency domain resources of a search space set. 19C is a conceptual diagram showing a fifth embodiment of a method for setting a CORESET and a frequency domain resource of a search space set, and FIG. 19D shows a sixth embodiment of a method for setting a CORESET and a frequency domain resource of a search space set. It is a conceptual diagram.

19A to 19D, search space set #1 may be mutually combined with CORESET #1. Search space set #1 may include one frequency domain occasion. The frequency domain in which the frequency domain occasion is arranged may be the same as the frequency domain of CORESET #1. Alternatively, the frequency domain in which the frequency domain occasion is arranged may be a frequency domain in which the frequency domain of CORESET #1 is shifted by a preset value (eg, Δf). In the embodiment shown in Fig. 19A, the candidate value(s) of Δf may include positive numbers. The absolute value of Δf or Δf may be greater than or equal to the bandwidth occupied by CORESET #1 (or the difference between the highest frequency and the lowest frequency in the frequency domain occupied by CORESET #1).

The frequency domain of search space set #1 may not partially overlap with the frequency domain of CORESET #1. That is, a partial overlap between the frequency domain of the search space set or each frequency domain occasion of the search space set and the frequency domain of CORESET may not be allowed, and "the search space set or each frequency domain of the corresponding search space set When the frequency domain completely overlaps the frequency domain of CORESET" or "when the frequency domain of the search space set or each frequency domain occasion of the search space set does not overlap the frequency domain of the CORESET" may be allowed. This operation may be referred to as “method 400”.

In the embodiments shown in FIGS. 18A and 18B, the candidate value(s) of Δf may include zero. In the embodiment shown in FIG. 19B, the candidate value(s) of Δf may include negative numbers. To avoid partial overlap between search space set #1 and CORESET #1, the absolute value of Δf may be greater than or equal to the bandwidth occupied by CORESET #1.

In the embodiment shown in FIG. 18A, a plurality of frequency domain occasions constituting the same search space set may be disposed in separate frequency domains without overlapping. A difference between offset values for a plurality of frequency domain occasions may be greater than or equal to the bandwidth of CORESET. Alternatively, a plurality of frequency domain occasions constituting the same search space set may be completely overlapped in the frequency domain. That is, different frequency domain occasions in the same search space set may have the same frequency offset from the frequency domain of the CORESET. In this case, the specific frequency domain occasion(s) may partially overlap with CORESET in the frequency domain. This operation may be referred to as “method 401”. Method 401 may be practiced in conjunction with method 400. Alternatively, method 401 may be implemented independently of method 400. For example, if method 401 is used, some frequency domain occasions may partially overlap with CORESET in the frequency domain.

In the embodiment shown in FIG. 19C, the absolute value of Δf or Δf may be less than the frequency bandwidth occupied by CORESET #1. In this case, the frequency domain of search space set #1 may partially overlap with the frequency domain of CORESET #1. Different frequency domain occasions in the same search space set may partially overlap in the frequency domain. The UE may perform a blind decoding operation on the PDCCH candidate(s) in each frequency domain occasion regardless of whether the frequency domain occasions overlap.

In the embodiment shown in FIG. 19D, CORESET #1 may be composed of a plurality of frequency clusters. In this case, the search space set(s) mutually combined with CORESET #1 and the frequency domain of the frequency domain occasion(s) in the search space set(s) may be set equally. In this case, the above-described search space set and resource allocation method of the frequency domain location may be applied in the same or similar manner. When CORESET is composed of a plurality of frequency clusters and the plurality of frequency clusters are discontinuous in the frequency domain, the bandwidth of CORESET may mean a difference between the highest frequency and the lowest frequency in the frequency domain of the CORESET. The bandwidth of CORESET can be distinguished from the frequency domain of CORESET.

The frequency position of each frequency domain occasion of the search space set may be expressed as an offset from the frequency domain of CORESET. For example, an offset between a first PRB configuring CORESET (eg, a PRB having the lowest frequency) and a first PRB configuring a frequency domain occasion may be set in the terminal. The setting unit of the frequency offset (eg, offset between PRBs) may be one PRB or K consecutive PRBs. Here, K may be an integer of 2 or more. K may be predefined in the technical standard. Alternatively, the base station may inform the terminal of K.

For example, the frequency offset may be defined as the difference between the index of the first PRB constituting the CORESET and the index of the first PRB of the frequency domain occasion. The K value may be set by RRC signaling and may be included in the configuration information of the bandwidth part. In the unlicensed band communication, K may be defined as a bandwidth occupied by one LBT subband or a value corresponding to the bandwidth (eg, the number of PRBs corresponding to 20 MHz or 20 MHz). For another example, K can be 6 or a multiple of 6. According to this method, a plurality of CORESETs of the terminal(s) may be arranged in the frequency domain in units of 6 RBs. The frequency offset candidate value may be an integer greater than or equal to 0. Alternatively, the candidate value of the frequency offset may include 0, a positive number, and a negative number.

Alternatively, the frequency position (eg, the position of the first PRB) of each frequency domain occasion of the search space set may be expressed as a CRB index or a CRB group index. The CRB index or the index of the CRB group may be set based on point A. Alternatively, the frequency position of each frequency domain location of the search space set may be expressed as a PRB index or a PRB group index in the bandwidth portion. On the other hand, when the LBT subband is set in the carrier or bandwidth portion, each frequency domain occasion may belong to one LBT subband. In this case, the frequency position of each frequency domain occasion may be expressed based on a local PRB index or a PRB group index within a corresponding LBT subband. For example, one CRB group or one PRB group may consist of L consecutive RBs. Here, L may be a natural number. For example, L can be 6 or a multiple of 6. Each CRB group may be defined in ascending order based on point A. For example, when L=6, the first CRB group may be composed of CRBs #0 to #5, and the second CRB group may be composed of CRBs #6 to #11. This operation can be repeated.

As another method, the frequency location (eg, the location of the first PRB) of each frequency domain occasion of the search space set may be expressed as a specific PRB of the LBT subband to which the frequency domain location belongs. For example, the specific PRB may be the first PRB of the LBT subband (eg, the PRB having the lowest index) or the first PRB excluding the guard PRB(s) in the LBT subband. In this case, the frequency position of each frequency domain occasion of the search space set may be determined by the index of the LBT subband, and the index of the LBT subband may be signaled to the terminal.

Alternatively, each frequency domain occasion may be indicated by a PRB shifted by a preset PRB offset from a specific PRB of the LBT subband. One or more PRB offsets may be defined. The PRB offset may be signaled from the base station to the terminal. Alternatively, the PRB offset may be the same as the PRB offset applied to CORESET. For example, the start PRB of CORESET may be shifted by L PRBs from a specific PRB (eg, the first PRB) of the LBT subband to which the corresponding CORESET belongs. Here, L may be a natural number. In this case, the start PRB of the frequency domain occasion of the search space set mutually combined with the CORESET may be shifted by L PRBs from the specific PRB (eg, the first PRB) of the LBT subband to which the frequency domain occasion belongs. . According to the above-described method, the PRB offset may not be signaled to the terminal.

Candidate frequency positions of the frequency domain location may be defined, and the bitmap may indicate one or more (or zero or more) of the candidate frequency positions. The base station can transmit the bitmap to the terminal. Each of the candidate frequency positions may be located in different LBT subbands (eg, RB set). Each bit of the bitmap may indicate whether a PDCCH monitoring occasion is mapped to each candidate frequency location. In addition, one or more candidate frequency positions may be preset, and the bitmap may indicate whether the PDCCH monitoring occasion is mapped to the set candidate frequency position(s). Frequency location information (eg, a bitmap) of the frequency domain location may be included in the setting information of the search space set.

In the embodiment shown in FIG. 19C, when a plurality of frequency domain occasions (eg, frequency domain occasions #1 and #2) of the same search space set partially or completely overlap in the frequency domain, a plurality of frequencies CCE(s) or PDCCH candidate(s) satisfying a specific condition among CCEs or PDCCH candidates constituting domain occasions may be excluded from CCE and PDCCH candidates counted by the base station and/or the terminal. For example, the first CCE(s) belonging to the frequency domain occasion #1 and the second CCE(s) belonging to the frequency domain occasion #2 overlap, and the first CCE(s) and the second CCE(s) When the channel estimation operation for is the same or overlapping, the base station and/or the terminal may count the number of the first CCE(s) or the second CCE(s) in the corresponding slot, and the channel estimation operation may be performed once. have.

For another example, when PDCCH candidate #1 of frequency domain occasion #1 and PDCCH candidate #2 of frequency domain occasion #2 satisfy a specific condition, the UE is PDCCH candidate #1 or PDCCH candidate #2 in the corresponding slot. Can be counted. The specific condition may include a condition that the decoding operation for PDCCH candidate #1 and the decoding operation for PDCCH candidate #2 are the same. In this case, the UE can simultaneously perform blind decoding operations of PDCCH candidates #1 and #2 by performing a single PDCCH decoding operation. Conditions for excluding a specific PDCCH candidate from the PDCCH candidate counted by the base station and/or the terminal may be as follows.

The first condition may be that PDCCH candidates #1 and #2 occupy the same time and frequency resources (eg, a set of CCE(s)). The second condition may be that the size of the DCI payload of PDCCH candidate #1 is the same as the size of the DCI payload of PDCCH candidate #2. The third condition may be that the same scrambling operation is applied to PDCCH candidates #1 and #2. The fourth condition may be that CRCs of DCIs transmitted through PDCCH candidates #1 and #2 are scrambled by the same RNTI. The RNTI may be C-RNTI, MCS-C-RNTI, CS-RNTI, or the like. The fifth condition may be that the DCI format of PDCCH candidate #1 is the same as the DCI format of PDCCH candidate #2. The sixth condition may be that the DCI formats of PDCCH candidates #1 and #2 are configured with the same fields. The size of each field included in the DCI format of PDCCH candidate #1 may be the same as or different from the size of each field included in the DCI format of PDCCH candidate #2.

If one or more of the above-described conditions are satisfied, the UE may count PDCCH candidate #1 or PDCCH candidate #2, and perform a monitoring operation on one or more PDCCH candidates among all PDCCH candidates capable of blind decoding per slot. have. For example, among the above-described conditions, first, second, third, and fourth conditions may be used.

Alternatively, when a plurality of frequency domain occasions (eg, frequency domain occasions #1 and #2) of the same set of search spaces partially or completely overlap in the frequency domain, CCE constituting frequency domain occasions Regardless of whether the PDCCH candidates overlap or not, the UE may count the PDCCH candidate(s) and perform a monitoring operation on the corresponding PDCCH candidate(s). For example, when PDCCH candidate #1 of frequency domain occasion #1 and PDCCH candidate #2 of frequency domain occasion #2 satisfy the above-described conditions, and the decoding operation for PDCCH candidates #1 and #2 is the same, PDCCH candidates #1 and #2 may be counted as different PDCCH candidates.

The PDCCH and PDCCH DM-RS may be transmitted in a search space set (eg, PDCCH monitoring occasion) mutually combined with CORESET or CORESET. In this case, if the CORESET combined with the search space set is CORESET #0, the PDCCH DM-RS transmitted from the search space set (for example, PDCCH monitoring occasion) is the first subcarrier of the first PRB constituting the CORESET. It can be mapped as a standard. This operation may mean that symbols constituting the PDCCH DM-RS sequence are sequentially mapped from a reference subcarrier to subcarriers to which the PDCCH DM-RS is mapped. The terminal performing the initial access procedure cannot know the frequency location of point A. Accordingly, the UE may assume the above-described DM-RS mapping in order to receive the PDCCH in the CORESET #0 and the search space set(s) of the corresponding CORESET #0.

When the frequency domain of the search space set is allowed to be set differently from the frequency domain of CORESET #0, the mapping operation of the PDCCH DM-RS in each frequency domain location of the search space set may be performed as follows. Method 410 may be a method of mapping a DM-RS based on a specific subcarrier in CORESET. For example, a specific subcarrier may be the first subcarrier of the first PRB of CORESET. Method 411 may be a method of mapping a DM-RS based on a specific subcarrier of each frequency domain occasion. For example, the specific subcarrier may be the first subcarrier of the first PRB of each frequency domain occasion. Method 412 maps the DM-RS based on a specific subcarrier of one frequency domain occasion (e.g., a frequency domain occasion arranged in the lowest frequency domain) among frequency domain occasion(s) mutually combined with CORESET. It can be a way to do it. For example, the specific subcarrier may be the first subcarrier of the first PRB of one frequency domain occasion. When CORESET is composed of a plurality of symbols, the DM-RS mapping method can be applied to each symbol. This operation will be described in the embodiments below.

FIG. 20A is a conceptual diagram showing a first embodiment of a method for mapping PDCCH DM-RS in a search space set, and FIG. 20B is a conceptual diagram showing a second embodiment of a method for mapping PDCCH DM-RS in a search space set, 20C is a conceptual diagram illustrating a third embodiment of a method for mapping a PDCCH DM-RS in a search space set.

20A and 20B, search space set #1 may be mutually combined with CORESET #1 and may include frequency domain occasion #1. The frequency domain in which the frequency domain occasion #1 is arranged may be different from the frequency domain of CORESET #1. In this case, the embodiment shown in FIG. 20A may be performed by method 410. The mapping position of the PDCCH DM-RS for frequency domain occasion #1 may be determined based on the first subcarrier of the first PRB of CORESET #1. The sequence of the PDCCH DM-RS is S(0), S(1), S(2), ... S(n), S(n+1), S(n+2) ... In the case of, the subcarrier to which S(0) is mapped is the first subcarrier of the first PRB of CORESET #1 among subcarriers to which the PDCCH DM-RS is mapped (hereinafter referred to as "effective subcarriers") or a subcarrier file thereafter. I can. The frequency of the subcarrier to which S(0) is mapped may not be smaller than the first subcarrier of the first PRB of CORESET #1. Sequences of the PDCCH DM-RS other than S(0) may be sequentially mapped to effective subcarriers after the subcarrier to which S(0) is mapped. Therefore, the first symbol (e.g., a symbol mapped to the lowest frequency resource) of the PDCCH DM-RS actually transmitted in the frequency domain occasion #1 is a symbol other than S(0) (e.g., S(n )).

The embodiment shown in FIG. 20B may be performed by method 411. The mapping position of the PDCCH DM-RS for the frequency domain occasion #1 will be determined based on the first subcarrier of the first PRB of the frequency domain location to which the PDCCH DM-RS belongs (eg, frequency domain occasion #1). I can. For example, the subcarrier to which S(0) is mapped may be the first subcarrier of the first PRB of the frequency domain occasion #1 among the effective subcarriers or a subcarrier after that. The frequency of the subcarrier to which S(0) is mapped may not be less than the frequency of the first subcarrier of the first PRB of the frequency domain occasion #1. Sequences of the PDCCH DM-RS other than S(0) may be sequentially mapped to effective subcarriers after the subcarrier to which S(0) is mapped. Therefore, the first symbol (eg, a symbol mapped to the lowest frequency resource) of the DM-RS actually transmitted in the frequency domain occasion #1 may be S(0).

In the embodiment shown in FIG. 20C, the search space set #1 may be mutually combined with CORESET #1 and may include frequency domain occasions #1 and #2. Frequency domain occasion #1 may be disposed in a frequency domain in which the frequency domain of CORESET #1 is shifted, and frequency domain occasion #2 may be disposed in a frequency domain of CORESET #1. Frequency domain occasion #1 may not overlap with frequency domain occasion #2. In this case, the PDCCH DM-RS mapping operation in each frequency domain occasion may be performed based on method 411. The mapping position of the PDCCH DM-RS for each frequency domain occasion may be determined based on the first subcarrier of the first PRB of each frequency domain location to which the PDCCH DM-RS belongs.

For example, the subcarrier to which the first symbol (e.g., S(0)) of the PDCCH DM-RS is mapped in each frequency domain occasion is the first subcarrier of the first PRB of each frequency domain occasion among effective subcarriers. Or it can be a sub-carrying file after that The frequency of the subcarrier to which the first symbol (eg, S(0)) of the PDCCH DM-RS is mapped may not be less than the frequency of the first subcarrier of the first PRB. The remaining symbols of the PDCCH DM-RS within each frequency domain location may be sequentially mapped to effective subcarriers after the subcarrier to which the first symbol is mapped. The PDCCH DM-RS sequence (eg, PDCCH DM-RS symbol) may be generated for each frequency domain occasion and may be mapped to each frequency domain occasion. The same PDCCH DM-RS sequence may be mapped to each frequency domain occasion. That is, the same PDCCH DM-RS sequence can be transmitted in each frequency domain occasion. "It is said that the PDCCH DM-RS sequences are the same" may mean "the length of the PDCCH DM-RS sequences and/or the symbol sequence (or symbol set) constituting the DM-RS sequences are the same".

According to method 411, the same PDCCH DM-RS mapping rule may be applied within the frequency domain location regardless of the frequency position of the frequency domain location. Also, even when the frequency domain occasion is disposed in a frequency domain lower than the frequency domain of CORESET, the same PDCCH DM-RS mapping rule may be applied. On the other hand, when method 410 is used, if the frequency domain occasion is placed in a frequency domain lower than the frequency domain of CORESET, the reference frequency for PDCCH DM-RS mapping (eg, the frequency to which S(0) is mapped) It may be impossible to map the PDCCH DM-RS sequences in ascending order. To solve this problem, the frequency offset between the frequency domain occasion and CORESET can be limited to zero or a positive number.

The DM-RS used for demodulation of the data channel (eg, PDSCH, PUSCH, PSSCH) may be mapped in the resource region of the data channel. The DM-RS may be transmitted along with the data channel. In this case, the DM-RS mapping for the data channel is applied to the set of search spaces in which the DCI scheduling the data channel is transmitted, the DCI format, and/or the RNTI applied to the DCI (eg, RNTI scrambling the CRC of the DCI). Can be determined by For example, when the DCI scheduling the PDSCH is transmitted through the type 0 PDCCH CSS set of CORESET #0, and the CRC of the DCI is scrambled with SI-RNTI, the PDSCH DM-RS is PRBs constituting CORESET #0. Among them, it may be mapped based on the first PRB (eg, the PRB having the lowest index) or the first subcarrier of the first PRB. The PDSCH DM-RS may be a DM-RS used for demodulation of the PDSCH. "When the DCI scheduling the PDSCH is transmitted through a search space set other than the Type 0 PDCCH CSS set of CORESET #0" or "When the CRC of the DCI scheduling the PDSCH is scrambled by an RNTI other than SI-RNTI", PDSCH The DM-RS may be mapped on the basis of CRB #0 (eg, the first CRB) or the first subcarrier of CRB #0.

When the frequency domain of the search space set is allowed to be set differently from the frequency domain of CORESET #0, the method of mapping the DM-RS of the data channel (eg, PDSCH, PUSCH, PSSCH) scheduled through CORESET #0 Can be performed as follows: Method 420 may be a method of mapping the DM-RS of the data channel based on a specific frequency position of CORESET #0 (eg, a first PRB or a first subcarrier of the first PRB). Method 420 may be applied when the offset between the frequency domain of the search space set in which DCI is transmitted and the frequency domain of CORESET #0 is 0 or more (that is, when the start PRB of the search space set is more than the start PRB of CORESET #0).

Method 421 is a method of mapping a DM-RS of a data channel based on a specific frequency position (eg, a first PRB or a first subcarrier of a first PRB) of a frequency domain location of a search space set in which a scheduling DCI is transmitted Can be Method 422 is to set the DM-RS of the data channel to the CORESET #0 and the specific frequency position of the lowest frequency domain occasion (e.g., the first PRB or the first PRB) among the frequency domain occasion(s). It may be a method of mapping based on subcarriers). The above-described methods can be used when the scheduling DCI satisfies a specific condition. The specific condition may include one or more of a condition in which the scheduling DCI is transmitted through a specific search space set, a condition in which a specific DCI format is used, and a condition in which the CRC of the DCI is scrambled by a specific RNTI. In addition, the specific conditions may further include "a condition in which the scheduling DCI is transmitted through a type 0 PDCCH CSS set" and "a condition in which the CRC of the scheduling DCI is scrambled by SI-RNTI".

In the above-described embodiments, one or more PDCCH monitoring occasions arranged in the frequency domain may share the same time resource (eg, the same symbol or the same set of symbols). One or more PDCCH monitoring occasions within one period of the search space set may be disposed on the time domain. The time domain configuration information may include the number and location of slots in which the PDCCH monitoring occasion is disposed, and the location of the start symbol of the PDCCH monitoring occasion within the slot.

The PDCCH monitoring occasion may be arranged on 2D resources in the time domain and the frequency domain. As a first arrangement method of PDCCH monitoring occasions, N PDCCH monitoring occasions may be set in the time domain, and M PDCCH monitoring occasions may be set in the frequency domain. That is, a method in which N×M PDCCH monitoring occasions are arranged may be considered. Each of N and M may be a natural number. The base station may transmit configuration information of a PDCCH monitoring occasion set in the time domain and configuration information of a PDCCH monitoring occasion set in the frequency domain to the terminal. The configuration information of the PDCCH monitoring occasion may include one or more of the number of PDCCH monitoring occasions, locations, and a sum of locations.

Positions of N PDCCH monitoring occasions in the time domain are T ₀ , T ₁ , ... , T _N-1 , and positions of M PDCCH monitoring occasions in the frequency domain are F ₀ , F ₁ , ... , F _{M- 1} can be defined. In this case, the sum of positions of PDCCH monitoring occasions in the time domain is T ₀ , T ₁ , ... , T _{N- 1} , and the sum of positions of PDCCH monitoring occasions in the frequency domain is F ₀ , F ₁ ,… , F _{M- 1} can be expressed. The location of each PDCCH monitoring occasion is (T ₀ , F ₀ ), (T ₀ , F ₁ ),… (T ₀ , F _M-1 ), (T ₁ , F ₀ ), (T ₁ , F ₁ ),… (T ₁ , F _M-1 ),… (T _N-1 , F ₀ ), (T _N-1 , F ₁ ),… , And (T _N-1 , F _{M- 1} ).

As a second arrangement method of PDCCH monitoring occasions, L PDCCH monitoring occasions may be set, and a combination between a time domain location and a frequency domain location of each of the L PDCCH monitoring occasions may be independently set. L can be a natural number. For example, the location of each PDCCH monitoring occasion is (T ₀ , F ₀ ), (T ₁ , F ₁ ),… It may correspond to (T _{L -1} , F _{L- 1} ). The flexibility of resource allocation according to the second allocation method may be higher than that of the resource allocation according to the first allocation method. The signaling overhead according to the second arrangement method may be greater than the signaling overhead according to the first arrangement method.

When a plurality of PDCCH monitoring occasions are configured in the frequency domain, a changed PDCCH and CCE mapping rule may be used. PDCCH candidates and CCEs may be mapped in a subdivided unit than a search space set. For example, when one search space set includes one or more PDCCH monitoring occasions in the frequency domain, PDCCH candidates and CCEs may be sequentially mapped from a search space set having a low ID, and a frequency within the search space set PDCCH candidates and CCEs in the domain may be sequentially mapped in units of PDCCH monitoring occasions. For example, PDCCH monitoring occasions in the frequency domain within the search space set may be mapped in ascending or descending order of IDs (eg, indexes). The cumulative value of the number of PDCCH candidates and CCEs for each mapping step may be compared with an upper limit value. The mapping operation of the PDCCH candidate and the CCE in a PDCCH monitoring occasion unit may be performed in a 2D resource in a frequency domain and a time domain.

The above-described method can be applied to any CORESET. Alternatively, the above-described method may not be applied to a specific CORESET. For example, the above-described method can be applied to CORESET except for CORESET (eg, CORESET #0) set through the PBCH or RRC parameter “ControlResourceSetZero”. The set of search spaces mutually coupled to CORESET #0 may include one frequency domain occasion, and one frequency domain occasion may be disposed in the frequency domain of CORESET #0. In addition, the above-described method can be applied to an arbitrary set of search spaces (eg, a CSS set, a USS set, etc.). Alternatively, the above-described method may not be applied to a specific search space set. For example, the above-described method can be applied to a search space set excluding a type 0 PDCCH CSS set.

Alternatively, the above-described method may not be applied to "when scheduling DCI according to a specific DCI format is used" or "when the CRC of DCI is scrambled with a specific RNTI". For example, the above-described method can be applied when the CRC of the scheduling DCI is scrambled with RNTIs excluding SI-RNTI. For another example, the above-described method may be applied to "when the scheduling DCI is transmitted in a search space set excluding the Type 0 PDCCH CSS set" or "when the CRC of the scheduling DCI is scrambled with an RNTI excluding SI-RNTI". . Alternatively, the above-described method may be applied to a search space set excluding search space set #0 (eg, a search space set with ID=0). Alternatively, the above-described method can be applied to the USS set.

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

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

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

Claims (20)

As a method of operating a terminal in a communication system,
Receiving first setting information of a control resource set (CORESET) and second setting information of a search space associated with the CORESET from a base station;
Receiving, from the base station, third configuration information indicating at least one physical downlink control channel (PDCCH) monitoring resource set associated with the CORESET and the search space; And
And performing a PDCCH monitoring operation on the one or more PDCCH monitoring resource sets,
Each of the one or more PDCCH monitoring resource sets is located in each RB (resource block) set set in an unlicensed band. The method according to claim 1,
Among the parameters included in the first configuration information and the second configuration information, parameters other than a parameter indicating a frequency domain resource are shared for the one or more PDCCH monitoring resource sets. The method according to claim 2,
The remaining parameters are information indicating a duration of the CORESET, information indicating a control channel element (CCE)-resource element group (REG) mapping type, and indicating whether to apply interleaving in a CCE-REG mapping operation. Information, information indicating the size of the REG bundle, interleaving rule information, shift index, precoder granularity information, transmission configuration information (TCI) state information, a field indicating the TCI state A method of operating a terminal comprising at least one of information indicating whether is present in downlink control information (DCI), and a scrambling identifier of a PDCCH demodulation-reference signal (DM-RS). The method according to claim 1,
The third configuration information is a bitmap, and each bit included in the bitmap indicates whether a PDCCH monitoring resource set is set in an RB set. The method of claim 4,
The size of the bitmap corresponds to the number of RB sets set in one bandwidth part. The method according to claim 1,
Each of the one or more PDCCH monitoring resource sets includes one or more RBs, the one or more PDCCH monitoring resource sets are disposed on a frequency domain without overlap, and one or more RB sets to which the one or more PDCCH monitoring resource sets belong Are located within one bandwidth portion, the operating method of the terminal. The method according to claim 1,
The CORESET is a CORESET, not a CORESET set through a physical broadcast channel (PBCH), a method of operating a terminal. The method according to claim 1,
The operating method of the terminal,
Further comprising the step of receiving a PDCCH from at least one of the one or more PDCCH monitoring resource sets,
At least one PDCCH monitoring resource set in which the PDCCH is received is located within RB sets in which a listen before talk (LBT) operation performed by the base station is successful. As a method of operating a base station in a communication system,
Transmitting first setting information of a control resource set (CORESET) and second setting information of a search space associated with the CORESET to a terminal;
Transmitting third configuration information indicating at least one PDCCH (physical downlink control channel) monitoring resource set associated with the CORESET and the search space to the terminal; And
Including the step of transmitting the PDCCH to the terminal through at least one of the one or more PDCCH monitoring resource sets,
Each of the one or more PDCCH monitoring resource sets is located in each RB (resource block) set set in an unlicensed band. The method of claim 9,
Among the parameters included in the first configuration information and the second configuration information, parameters other than a parameter indicating a frequency domain resource are shared for the one or more PDCCH monitoring resource sets. The method of claim 10,
The remaining parameters are information indicating a duration of the CORESET, information indicating a control channel element (CCE)-resource element group (REG) mapping type, and indicating whether to apply interleaving in a CCE-REG mapping operation. Information, information indicating the size of a REG bundle, interleaving rule information, shift index, precoder granularity information, transmission configuration information (TCI) state information, a field indicating the TCI state A method of operating a base station, comprising at least one of information indicating whether is present in downlink control information (DCI), and a scrambling identifier (ID) of a PDCCH demodulation-reference signal (DM-RS). The method of claim 9,
The third configuration information is a bitmap, and each bit included in the bitmap indicates whether a PDCCH monitoring resource set is set in an RB set. The method of claim 9,
Each of the one or more PDCCH monitoring resource sets includes one or more RBs, the one or more PDCCH monitoring resource sets are disposed on a frequency domain without overlap, and one or more RB sets to which the one or more PDCCH monitoring resource sets belong Are located within one bandwidth portion, the method of operation of the base station. The method of claim 9,
The CORESET is a CORESET that is not a CORESET set through a physical broadcast channel (PBCH), a method of operating a base station. The method of claim 9,
At least one PDCCH monitoring resource set through which the PDCCH is transmitted is located within RB sets in which a listen before talk (LBT) operation performed by the base station is successful. As a terminal in a communication system,
Processor;
A memory in electronic communication with the processor; And
Contains instructions stored in the memory,
When the instructions are executed by the processor, the instructions are the terminal,
Receiving first setting information of a control resource set (CORESET) and second setting information of a search space associated with the CORESET from a base station;
Receiving, from the base station, third configuration information indicating the CORESET and one or more physical downlink control channel (PDCCH) monitoring resource sets associated with the search space; And
Operates to cause to perform a PDCCH monitoring operation in the one or more PDCCH monitoring resource sets,
Each of the one or more PDCCH monitoring resource sets is located in each RB (resource block) set set in an unlicensed band. The method of claim 16,
Among the parameters included in the first configuration information and the second configuration information, parameters other than a parameter indicating a frequency domain resource are shared for the one or more PDCCH monitoring resource sets. The method of claim 16,
The third configuration information is a bitmap, and each bit included in the bitmap indicates whether a PDCCH monitoring resource set is set in an RB set. The method of claim 16,
Each of the one or more PDCCH monitoring resource sets includes one or more RBs, the one or more PDCCH monitoring resource sets are disposed on a frequency domain without overlap, and one or more RB sets to which the one or more PDCCH monitoring resource sets belong Are located within one bandwidth portion, the terminal. The method of claim 16,
The CORESET is a CORESET that is not a CORESET set through a physical broadcast channel (PBCH), the terminal.

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