KR20200099973A - Measurement method and apparatus for supporting mobility in communication system - Google Patents

Abstract

A measurement method for mobility support in a communication system and an apparatus thereof are disclosed. According to the present invention, an operation method of a terminal comprises the steps of: receiving, from a base station, control information including first information indicating one or more physical uplink shared channel (PUSCH) interlaces set in an unlicensed band; checking frequency resources corresponding to the one or more PUSCH interlaces; and transmitting a PUSCH to the base station using the frequency resources of the unlicensed band. Accordingly, the performance of the communication system can be improved.

Description

MEASUREMENT METHOD AND APPARATUS FOR SUPPORTING MOBILITY IN COMMUNICATION SYSTEM}

The present invention relates to a measurement technology in a communication system, and more particularly, to a radio resource management (RRM) measurement technology for supporting mobility.

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).

The NR communication system can simultaneously support one or more usage scenarios. In an NR communication system supporting one or more use scenarios, configuration variables (eg, numerology) of an orthogonal frequence division multiplexing (OFDM) waveform may be variously set. Various neurology can be used in the NR communication system. When a time division duplex (TDD)-based NR communication system supports eMBB and URLLC, the low-latency performance of URLLC needs to be improved.

In the downlink (DL) data transmission procedure, since it is necessary to transmit a hybrid automatic repeat request (HARQ) response (eg, acknowledgment (ACK) or negative ACK (NACK)) for DL data, the delay time in the DL data transmission procedure is It may be determined according to the configuration of the DL slot and the UL (uplink) slot. Since it is necessary to transmit a HARQ response to UL data in the UL data transmission procedure, the delay time in the UL data transmission procedure may be determined according to the configuration of the DL slot and the UL slot.

In the NR communication system, the type of slot or symbol can be dynamically changed according to the situation. The terminal can know whether the symbol type is a DL symbol, a UL symbol, or a flexible (FL) symbol. The FL symbol can be changed to a DL symbol or a UL symbol. There is a need for methods for efficiently performing radio resource management (RRM) measurement in such an NR communication system.

An object of the present invention for solving the above problems is to provide a measuring method and apparatus for supporting mobility in a communication system.

In order to achieve the above object, a method of operating a terminal according to a first embodiment of the present invention includes receiving control information from a base station including first information indicating one or more PUSCH interlaces set in an unlicensed band, the one or more And checking frequency resources corresponding to PUSCH interlaces, and transmitting a PUSCH to the base station by using the frequency resources of the unlicensed band.

Here, the first information may be a bitmap, and each of the bits included in the bitmap may indicate a PUSCH interlace allocated for the terminal.

Here, the first information may be an index, and the index may indicate a combination of the one or more PUSCH interlaces allocated for the terminal.

Here, the index may include information indicating a start PUSCH interlace among the one or more PUSCH interlaces and information indicating the number of the one or more PUSCH interlaces.

Here, a method of indicating the one or more PUSCH interlaces may be different according to a subcarrier interval of the BWP to which the one or more PUSCH interlaces belong.

Here, the control information may further include second information indicating one or more resource block (RB) sets set by the base station, and each of the one or more RB sets may include one or more RBs.

Here, the one or more RB sets may be frequency resources indicated by the base station.

Here, the second information may be a bitmap, and each of the bits included in the bitmap may indicate a set of RBs allocated for the terminal.

Here, when a plurality of RB sets are set by the base station, a guard band may be located between the plurality of RB sets, and the PUSCH may be mapped to one or more RBs belonging to the plurality of RB sets. have.

Here, the PUSCH may be transmitted in the one or more PUSCH instances belonging to the one or more RB sets and the one or more PUSCH instances belonging to RBs other than the one or more RB sets, and the one or more RB sets The type of LBT operation performed for transmission of the PUSCH may be different from the type of the LBT operation performed for transmission of the PUSCH in RBs other than the one or more RB sets.

Here, the PUSCH may be transmitted in a time interval other than the COT and the COT set by the base station, and the type of LBT operation performed for transmission of the PUSCH in the COT is the PUSCH in a time interval other than the COT. It may be different from the type of the LBT operation performed for transmission.

Here, the time interval in which the PUSCH can be transmitted may include a plurality of PUSCH instances, and when one or more PUSCH instances among the plurality of PUSCH instances do not belong to the COT set by the base station, the PUSCH is in the time interval. May not be transmitted.

Here, the time interval in which the PUSCH can be transmitted may include a plurality of PUSCH instances, and when one or more PUSCH instances among the plurality of PUSCH instances do not belong to the COT set by the base station, the PUSCH is the plurality of PUSCH instances. Among the instances, it may be transmitted in the remaining PUSCH instances excluding the one or more PUSCH instances.

Here, the control information may include third information indicating a structure of one or more slots included in the COT set by the base station, and the third information included in different control information received from the base station is The same slot structure can be indicated.

In order to achieve the above object, a method of operating a base station according to a second embodiment of the present invention includes generating first information indicating one or more PUSCH interlaces set in an unlicensed band, and providing control information including the first information. Transmitting to a terminal, and receiving a PUSCH from the terminal through frequency resources corresponding to the one or more PUSCH interlaces in the unlicensed band.

Here, the first information may be a bitmap or an index, and a method of indicating the one or more PUSCH interlaces may be different according to a subcarrier interval of the BWP to which the one or more PUSCH interlaces belong.

Here, the index may include information indicating a start PUSCH interlace among the one or more PUSCH interlaces and information indicating the number of the one or more PUSCH interlaces.

Here, the control information may further include second information indicating one or more RB sets set by the base station, each of the one or more RB sets may include one or more RBs, and the one or more RB sets May be COT frequency resources set by the base station.

Here, when a plurality of RB sets are set by the base station, a guard band may be located between the plurality of RB sets, and the PUSCH may be mapped to one or more RBs belonging to the plurality of RB sets. have.

Here, the PUSCH may be received through the one or more PUSCH instances belonging to the one or more RB sets and the one or more PUSCH instances belonging to RBs other than the one or more RB sets, and the one or more RB sets The type of LBT operation performed for transmission of the PUSCH may be different from the type of the LBT operation performed for transmission of the PUSCH in RBs other than the one or more RB sets.

According to the present invention, a channel state information-reference signal (CSI-RS) resource may be used as a radio resource management (RRM)-RS resource or a tracking reference signal (TRS) resource. Accordingly, the UE may perform an RRM measurement operation or a downlink (DL) management operation based on a reference signal received from a CSI-RS resource. In addition, the base station may inform the terminal of zero power (ZP) resource information and/or non-ZP (NZP) resource information. The terminal may perform a rate matching operation or a puncturing operation for a data channel based on the ZP resource information and/or NZP resource information obtained from the base station.

In addition, the base station may transmit a COT indicator indicating time resource information and frequency resource information of a channel occupancy time (COT) to the terminal. The terminal may check the resource structure of the COT secured by the base station based on the COT indicator, and may perform a DL reception operation and/or an uplink (UL) transmission operation based on the resource structure of the COT. Therefore, 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 illustrating multiplexing pattern #1 of an SS/PBCH block, CORESET 0, and SIB type 1 in a communication system.
3B is a conceptual diagram illustrating multiplexing pattern #2 of an SS/PBCH block, CORESET 0, and SIB type 1 in a communication system.
3C is a conceptual diagram illustrating multiplexing pattern #3 of an SS/PBCH block, CORESET 0, and SIB type 1 in a communication system.
4A is a conceptual diagram illustrating a first embodiment of a method for multiplexing an SS/PBCH block and a CSI-RS in a DRS slot of a communication system.
4B is a conceptual diagram illustrating a second embodiment of a method for multiplexing an SS/PBCH block and a CSI-RS in a DRS slot of a communication system.
5A is a conceptual diagram illustrating a third embodiment of a method for multiplexing an SS/PBCH block and a CSI-RS in a DRS slot of a communication system.
5B is a conceptual diagram illustrating a fourth embodiment of a method for multiplexing an SS/PBCH block and a CSI-RS in a DRS slot of a communication system.
6 is a conceptual diagram showing a first embodiment of a TRS arrangement method in a communication system.
7 is a conceptual diagram showing a second embodiment of a TRS arrangement method in a communication system.
8 is a conceptual diagram illustrating a first embodiment of a method for indicating resource information of CSI-RS in a communication system.
9 is a conceptual diagram illustrating a first embodiment of a method for mapping a COT indicator in a communication system.
10 is a conceptual diagram illustrating a second embodiment of a method for mapping a COT indicator in a communication system.
11 is a conceptual diagram showing a third embodiment of a method for mapping a COT indicator in a communication system.
12 is a conceptual diagram showing a fourth embodiment of a method for mapping a COT indicator in a communication system.
13 is a conceptual diagram showing a first embodiment of a method of performing an LBT operation in a communication system.
14 is a conceptual diagram showing a second embodiment of a method of performing an LBT operation in a communication system.
15 is a conceptual diagram showing a third embodiment of a method of performing an LBT operation in a communication system.

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

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

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

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

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

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

A communication system to which embodiments according to the present invention are applied will be described. 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.

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). A plurality of communication nodes are 4G communication (e.g., long term evolution (LTE), LTE-A (advanced)), 5G communication (e.g., new radio) specified in the 3rd generation partnership project (3GPP) standard. ), etc. 4G communication may be performed in a frequency band of 6 GHz or less, and 5G communication may be performed in a frequency band of 6 GHz or more as well as a frequency band of 6 GHz or less.

For example, for 4G communication and 5G communication, a plurality of communication nodes may include a code division multiple access (CDMA)-based communication protocol, a wideband CDMA (WCDMA)-based communication protocol, a time division multiple access (TDMA)-based communication protocol, Frequency division multiple access (FDMA)-based communication protocol, OFDM (orthogonal frequency division multiplexing)-based communication protocol, Filtered OFDM-based communication protocol, CP (cyclic prefix)-OFDM-based communication protocol, DFT-s-OFDM (discrete) Fourier transform-spread-OFDM)-based communication protocol, OFDMA (orthogonal frequency division multiple access)-based communication protocol, SC (single carrier)-FDMA-based communication protocol, NOMA (Non-orthogonal Multiple Access), GFDM (generalized frequency) Division multiplexing) based communication protocol, FBMC (filter bank multi-carrier) based communication protocol, UFMC (universal filtered multi-carrier) based communication protocol, SDMA (Space Division Multiple Access) based communication protocol can be supported. .

In addition, the communication system 100 may further include a core network. When the communication system 100 supports 4G communication, the core network may include a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), a mobility management entity (MME), and the like. have. When the communication system 100 supports 5G communication, the core network may include a user plane function (UPF), a session management function (SMF), an access and mobility management function (AMF), and the like.

Meanwhile, a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130- constituting the communication system 100 4, 130-5, 130-6) Each 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.

However, each of the components included in the communication node 200 may be connected through an individual interface or an individual bus centering on the processor 210 instead of the common bus 270. For example, the processor 210 may be connected to at least one of the memory 220, the transmission/reception device 230, the input interface device 240, the output interface device 250, and the storage device 260 through a dedicated interface. .

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). Base stations (110-1, 110-2, 110-3, 120-1, 120-2) and terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) The containing communication system 100 may be referred to as an “access network”. 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, an evolved NodeB, gNB, and a base transceiver station (BTS). ), a radio base station, a radio transceiver, an access point, an access node, and the like. Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 is a user equipment (UE), a terminal, an access terminal, and a mobile device. It may be referred to as a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, 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)). Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 is a base station 110-1, 110-2, 110-3, 120-1 , 120-2) and operations supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be performed. For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 based on the SU-MIMO scheme, and the fourth terminal 130-4 may transmit a signal to the fourth terminal 130-4 by the SU-MIMO scheme. A signal may be received from the second base station 110-2. Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 based on the MU-MIMO method, and the fourth terminal 130-4 And each of the fifth terminal 130-5 may receive a signal from the second base station 110-2 by the MU-MIMO method.

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

Next, measurement methods in the communication system will be described. Even when a method performed in the first communication node (for example, transmission or reception of a signal) among communication nodes is described, the second communication node corresponding thereto is a method corresponding to the method performed in the first communication node (e.g. For example, signal reception or transmission) may be performed. That is, when the operation of the terminal is described, the corresponding base station may perform an operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the terminal corresponding thereto may perform an operation corresponding to the operation of the base station.

In the following embodiments, the base station may refer to a serving base station, and the terminal may refer to a terminal connected to the serving base station. The higher layer signaling operation may be an operation of exchanging a radio resource control (RRC) message including configuration information between the base station and the terminal.

In a communication system, the base station may periodically transmit a reference signal. The terminal may receive the reference signal from the base station, and may determine the radio link quality between the base station and the terminal based on the measurement result of the reference signal. The base station may measure channel state information (CSI) to perform scheduling according to the dynamic quality of the radio link. The base station may measure reference signal received power (RSRP), reference signal received quality (RSRQ), signal to interference plus noise ratio (SINR), and the like to support mobility according to the static quality of the radio link.

The communication system can operate in the unlicensed band. In this case, the transmitter may determine whether the radio resources are used by other communication nodes by performing a measurement operation (eg, a sensing operation) on the radio resources. In the DL communication procedure, the transmitter may be a base station, and in the UL communication procedure, the transmitter may be a terminal. The radio access technology (RAT) of the transmitter may be the same as or different from the RAT of other communication nodes. When there is no other communication node using radio resources, the transmitter may transmit a signal and/or a channel using the radio resources. When another communication node using radio resources exists, the transmitter may not transmit a signal and/or a channel using the radio resources. Regulation of the unlicensed band may not guarantee that one transmitter periodically transmits signals and/or channels. Accordingly, the transmitter may transmit signals and/or channels aperiodically by performing a sensing operation.

In a communication system supporting a licensed band, a reference signal may be periodically transmitted. In this case, the mobility of the terminal can be stably supported. For example, the terminal may perform a radio resource management (RRM) measurement operation based on the reference signal, and may inform the base station of the RRM measurement result. The base station may support mobility of the terminal based on the RRM measurement result. In addition, the UE may perform a CSI measurement operation based on a reference signal and may inform the base station of the CSI measurement result. The base station may perform a dynamic scheduling operation based on the CSI measurement result. In addition, the time offset and the frequency offset may be canceled based on a measurement result of a tracking reference signal (TRS). However, since the base station may not be able to transmit the reference signal according to the result of the sensing operation, the above-described operations may not be performed in the unlicensed band. In this case, the terminal may not be able to perform operations based on the reference signal.

It may not be guaranteed to periodically perform the RRM measurement operation in the unlicensed band. In addition, it may not be guaranteed that the terminal periodically receives a synchronization signal for an initial access operation (eg, a cell search operation) in an unlicensed band. According to the 3GPP technical standard, the base station may inform the terminal of the locations of approximate time resources through which a synchronization signal/physical broadcast channel (SS/PBCH) block is transmitted. The terminal may receive a synchronization signal (eg, SS/PBCH block) without prior information.

The CSI-RS (reference signal) may be used as an RRM-RS or a TRS. After the RRC (radio resource control) connection between the terminal and the base station is completed, the terminal may receive a CSI-RS from the base station. The base station may inform the UE of the location of frequency resources, sequence resources, and approximate time resources for CSI-RS transmission. However, the base station may not be able to inform the UE of the exact location of time resources through which the CSI-RS is transmitted. The base station may set a discovery time interval of a discovery reference signal (DRS) block to the terminal in the unlicensed band. The discovery time interval of the DRS block may include one or more slots or one or more subframes.

That is, the UE may obtain location information of approximate time resources for CSI-RS reception (eg, a discovery time interval of a DRS block) from the base station in an explicit or implicit method. The approximate time resources for CSI-RS reception may mean consecutive slots or consecutive subframes in the time domain. For example, the approximate length of time resources for CSI-RS reception may be 5 ms (millisecond). The UE may receive a reference signal (eg, CSI-RS) in one or more slots among slots (eg, DRS slots) belonging to approximate time resources for CSI-RS reception. The base station may perform a listen to before talk (LBT) operation in DRS slots. The base station may not be able to transmit the reference signal in all DRS slots according to the result of performing the LBT operation.

DRS Composition

The DRS slot may be classified into a DSR slot including only DRS and a DRS slot including both DRS and data. The base station may perform a short LBT operation in a DRS slot including only DRS, and may perform a long LBT operation in a DRS slot including both DRS and data. In addition, the base station may select configuration variables used for the LBT operation according to the access priority of data. The UE cannot know the type of LBT operation performed by the base station (eg, a short LBT operation or a long LBT operation) and configuration variables for the LBT operation. Therefore, the DRS slot may have the same configuration regardless of multiplexing of DRS and data.

The SS/PBCH block may be transmitted according to various subcarrier intervals (eg, 15 kHz, 30 kHz, etc.). The subcarrier spacing of the SS/PBCH block may be different from the subcarrier spacing of other signals and/or channels transmitted through the DRS slot. Another signal transmitted through the DRS slot may be a CSI-RS. Other channels transmitted through the DRS slot may be a physical downlink control channel (PDCCH) (eg, a control resource set (CORESET)), a physical downlink shared channel (PDSCH), or the like.

The SS/PBCH block, CORESET 0, and system information block (SIB) type 1 may be multiplexed. SIB type 1 may be a remaining minimum system information (RMSI) block. The multiplexing pattern can be defined as follows.

3A is a conceptual diagram illustrating a multiplexing pattern #1 of an SS/PBCH block, CORESET 0, and SIB type 1 in a communication system, and FIG. 3B is a multiplexing pattern of an SS/PBCH block, CORESET 0, and SIB type 1 in a communication system. #2 is a conceptual diagram, and FIG. 3C is a conceptual diagram illustrating a multiplexing pattern #3 of an SS/PBCH block, CORESET 0, and SIB type 1 in a communication system.

3A to 3C, CORESET may be CORESET 0, and SIB type 1 (eg, RMSI block) may be transmitted through PDSCH. In the multiplexing pattern #1, the SS/PBCH block may be multiplexed with a "CORESET 0 and RMSI block" and a time division multiplexing (TDM) method. In the multiplexing pattern #2, symbols in which the SS/PBCH block is located may be different from the symbol(s) in which CORESET 0 is located, and the SS/PBCH block may be multiplexed with an RMSI block in a frequency division multiplexing (FDM) method. In multiplexing pattern #3, the SS/PBCH block may be multiplexed with an RSMI block and an FDM scheme. In this case, data may be multiplexed in a DRS slot.

In the following embodiments, a method of multiplexing a CSI-RS and an SS/PBCH block will be described. Here, CSI-RS may be used as RRM-RS or TRS. The DRS may include one or more SS/PBCH blocks and one or more CSI-RSs. That is, the DRS slot may include resources for one or more SS/PBCH blocks and resources for one or more CSI-RSs. The SS/PBCH block may include a synchronization signal and a PBCH. The synchronization signal may include a primary synchronization signal (PSS) and a secondary synchronization signal (SSS).

4A is a conceptual diagram showing a first embodiment of a method for multiplexing an SS/PBCH block and a CSI-RS in a DRS slot of a communication system, and FIG. 4B is a multiplexing of an SS/PBCH block and a CSI-RS in a DRS slot of a communication system. A conceptual diagram showing a second embodiment of the method.

4A, one SS/PBCH block in one DRS slot may be multiplexed with one CSI-RS and TDM scheme. Referring to FIG. 4B, a plurality of SS/PBCH blocks may be multiplexed with a plurality of CSI-RSs in a TDM scheme in one DRS slot. The positions of the SS/PBCH block and CSI-RS in the DRS slot may be variously set. The symbol(s) in which the CSI-RS is located may not overlap with the symbols in which the SS/PBCH block is located.

In the frequency domain, the SS/PBCH block may be located in the middle or edge of the bandwidth part (BWP) to which the CSI-RS is mapped. The base station may configure the CSI-RS resource(s) to the terminal using higher layer signaling. In the time domain, the SS/PBCH block may be located before the CSI-RS. Alternatively, in the time domain, the SS/PBCH block may be located behind the CSI-RS. The symbols in which the SS/PBCH block is located may be contiguous with the symbol(s) in which the CSI-RS is located. Alternatively, symbols in which the SS/PBCH block is located may not be contiguous with the symbol(s) in which the CSI-RS is located. If the symbols in which the SS/PBCH block is located are not contiguous with the symbol(s) in which the CSI-RS is located, the base station is a symbol that is not occupied by the SS/PBCH block or CSI-RS in the DRS slot to satisfy frequency regulation S) can transmit other signals and/or channels (eg, data channels).

When the SS/PBCH block is multiplexed in a CSI-RS and TDM scheme, a method of additionally multiplexing an RMSI block in a DRS slot may be considered. Downlink control information (DCI) (for example, cyclic redundancy check (CRC) of DCI) for scheduling the PDSCH in which the RMSI block is transmitted is a cell-radio network temporary identifier (C-RNTI), modulation and coding scheme (MCS)- It may be scrambled by C-RNTI or CS (configured scheduling)-RNTI. Alternatively, the DCI (e.g., CRC of DCI) scheduling the PDSCH in which the RMSI block is transmitted may be scrambled by SI (system information)-RNTI, P (paging)-RNTI, or RA (random access)-RNTI. have.

A terminal operating in an RRC connected state may receive a PDSCH (eg, an RMSI block) from a base station. In this case, the PDSCH may be allocated by DCI format 1_0 (eg, DCI-1_0) or DCI format 1_1 (eg, DCI_1-1).

The PDSCH (eg, PDSCH-1_1) dynamically allocated by DCI-1_1 may include zero power (ZP) resources. In this case, the UE may assume that PDSCH-1_1 is not mapped in REs (resource elements) (eg, ZP resources) indicated by the base station, and accordingly performs a decoding operation on PDSCH-1_1 can do.

On the other hand, the PDSCH (eg, PDSCH-1_0) allocated by DCI-1_0 may not include ZP resources. In this case, the UE maps PDSCH-1_0 from the remaining resources except for the exception resources defined in the 3GPP technical standard (eg, resources for transmitting the SS/PBCH block) among the resources allocated by DCI-1_0 It can be assumed to be, and accordingly, a decoding operation on PDSCH-1_0 can be performed.

The UE may not know the location of the CSI-RS resource in PDSCH-1_0 including the RMSI block. Accordingly, the CSI-RS may be located in symbol(s) different from the symbols occupied by PDSCH-1_0. That is, the base station may schedule PDSCH-1_0 so that symbols occupied by PDSCH-1_0 are different from symbol(s) occupied by CSI-RS. In addition, the base station may inform the terminal of the location of the CSI-RS resource.

Two SS/PBCH blocks having a subcarrier interval of 15 kHz may be located in a 1 ms DRS slot. The DRS slot may include 14 symbols, and the SS/PBCH block and CSI-RS may be located in 7 consecutive symbols among 14 symbols. The RMSI block may also be located in the DRS slot. According to the multiplexing pattern #1 shown in FIG. 3A, an SS/PBCH block can be multiplexed with an RMSI block and a TDM scheme, the SS/PBCH block can occupy 4 symbols, and the RMSI block occupies 4 symbols. can do. In this case, considering the symbols occupied by the CSI-RS, the number of symbols required for multiplexing the SS/PBCH block, the RMSI block, and the CSI-RS may exceed seven. When 7 consecutive symbols are used in the DRS slot, an RMSI block for one SS/PBCH block may be transmitted in the corresponding 7 consecutive symbols. Alternatively, when the position of the SS/PBCH block is changed and the CSI-RS is mapped to one symbol, the SS/PBCH block and the CSI-RS may be located in a half slot.

One DRS slot may include two SS/PBCH blocks and one RMSI block. Here, two SS/PBCH blocks may occupy 8 symbols, and one RMSI block may occupy 4 symbols. In this case, 12 symbols may be used among 14 symbols constituting one DRS slot. The CSI-RS may be mapped to the remaining two symbols in the DRS slot. The above-described limitation may not be applied to the case in which the base station allocates PDSCH-1_1. Also, the above-described limitation may not be applied to a case in which the base station allocates PDSCH-1_0 to another slot. In the proposed method, PDSCH-1_0 may be mapped to resources (eg, REs) other than the CSI-RS resource.

In the proposed method, the CSI-RS in the DRS slot may be multiplexed in an SS/PBCH block and an FDM scheme. The symbol(s) occupied by the CSI-RS may overlap with symbols occupied by the SS/PBCH block. The base station may not map the CSI-RS to the RE to which the SS/PBCH block is mapped. CSI-RS can be used as TRS or RRM-RS. The terminal operating in the RRC connected state can receive system information from the base station, and can check time and frequency resources at which the SS/PBCH block is transmitted based on the system information. Therefore, the UE may assume that the CSI-RS is mapped to RE(s) not occupied by the SS/PBCH block.

5A is a conceptual diagram showing a third embodiment of a method for multiplexing an SS/PBCH block and a CSI-RS in a DRS slot of a communication system, and FIG. 5B is a multiplexing of an SS/PBCH block and a CSI-RS in a DRS slot of a communication system. It is a conceptual diagram showing a fourth embodiment of the method.

5A and 5B, one SS/PBCH block may be multiplexed with a CSI-RS in a DRS slot. When two or more SS/PBCH blocks are located in the DRS slot, each of the two or more SS/PBCH blocks may overlap with the CSI-RS. The positions of the SS/PBCH block and the CSI-RS in the DRS slot may be variously set. In the embodiment shown in FIG. 5A, the SS/PBCH block may be located in the middle of the BWP. In this case, in the frequency domain, the CSI-RS may be located in an upper region and a lower region of the SS/PBCH block. In the embodiment shown in FIG. 5B, the SS/PBCH block may be located at the edge of the BWP. In this case, in the frequency domain, the CSI-RS may be located in an upper region or a lower region of the SS/PBCH block.

In consideration of data transmission, the UE may not know the location of the CSI-RS resource in PDSCH-1_0 including the RMSI block. Accordingly, the CSI-RS may be located in symbol(s) different from the symbols occupied by PDSCH-1_0. That is, the base station may schedule PDSCH-1_0 so that symbols occupied by PDSCH-1_0 are different from symbol(s) occupied by CSI-RS. Meanwhile, in the multiplexing pattern #1 shown in FIG. 3A, an RMSI block (eg, PDSCH-1_0) may be multiplexed with an SS/PBCH block in a TDM manner. Therefore, in the DRS slot, PDSCH-1_0 may be multiplexed with CSI-RS and TDM scheme.

How to set up TRS resources

CSI-RS can be used as TRS. In this case, the TRS resource may be used as a CSI-RS resource. A terminal operating in an RRC connected state may receive a broadband reference signal and manage downlink synchronization using a broadband reference signal in the time and frequency domain. Here, the broadband reference signal may mean a reference signal transmitted through a broadband. The TRS resource may be an example of a CSI-RS resource. The TRS may be transmitted periodically or aperiodically.

In the proposed method, a resource for DRS measurement (eg, a CSI-RS resource) may be configured in the terminal independently of the TRS resource. The base station may inform the terminal of approximate time resources information (eg, TRS measurement time configuration (TMTC) information) for TRS measurement by using higher layer signaling. The approximate time resources may be composed of one or more slots or one or more subframes, and among one or more slots or one or more subframes, a slot(s) or subframe(s) in which TRS resources are set may exist . The base station may transmit the TRS by performing the LBT operation, and the TRS may not be transmitted in a specific slot or a specific subframe according to the result of performing the LBT operation. The base station may inform the terminal of information on a time window including candidate slots (or candidate subframes) in which the TRS can be transmitted. Here, the time window for TRS measurement may be referred to as TMTC.

In the proposed method, the time window for DRS measurement (eg, DRS mesaurement time configuration (DMTC)) may include TMTC. The base station may inform the terminal of approximate time resources information (eg, DMTC information) for DRS measurement using higher layer signaling. The approximate time resources may include one or more slots or one or more subframes. DMTC information may include TMTC information. The terminal may derive the time resource(s) in which the TRS is transmitted from the DRS slot.

TRS time resource

The TRS resource may be a CSI-RS resource. The TRS may have one antenna port, and may be repeatedly transmitted in a plurality of symbols. The position of the symbol (hereinafter referred to as "TRS symbol") through which the TRS is transmitted may be defined within the slot. The location of the TRS symbol may be changed according to settings. For example, the TRS is "Symbol #4 (for example, the 5th symbol) and symbol #8 (for example, the 9th symbol)", "Symbol #5 (for example, the 6th symbol)" in one slot. Symbol) and symbol #9 (eg, the 10th symbol)", and/or "symbol #6 (eg, the 7th symbol) and symbol #10 (eg, the 11th symbol)" I can. The spacing between the TRS symbols may be 4 symbols. The base station may inform the UE of the location of the first TRS symbol in the slot. The UE may estimate the location of the remaining TRS symbol(s) based on the distance between the TRS symbols and the location of the first TRS symbol.

One slot may consist of half slot #1 and half slot #2. When one slot includes symbols #0 to #13, half slot #1 may include symbols #0 to #6, and half slot #2 may include symbols #7 to #13. have. The last symbol of half slot #1 (eg, symbol #6) and the last slot of half slot #2 (eg, symbol #13) may be set as TRS symbols. In this case, the base station may inform the terminal of the location of the first TRS symbol. The UE may estimate the location of the remaining TRS symbol(s) based on the location of the first TRS symbol.

The TRS can be multiplexed with the SS/PBCH block. Within one slot, the TRS may be mapped in units of two symbols. The TRS may be multiplexed in the same slot as the SS/PBCH block. That is, the TRS and SS/PBCH blocks may be transmitted in the same slot.

In the proposed method, the SS/PBCH block can be multiplexed in a TRS and FDM scheme. In this case, the TRS may not be mapped to REs occupied by the SS/PBCH block. Accordingly, the UE may assume that the TRS is not mapped to some physical resource blocks (PRBs) of a specific TRS symbol, and may assume that the TRS is mapped to all PRBs of the remaining TRS symbol(s).

6 is a conceptual diagram showing a first embodiment of a TRS arrangement method in a communication system.

Referring to FIG. 6, the first symbol of the SS/PBCH block may overlap with the TRS symbol. The TRS symbol may be located in any symbol among symbols to which the SS/PBCH block is mapped according to the configuration of the base station. Alternatively, the TRS symbol may be located in a specific symbol among symbols to which the SS/PBCH block is mapped. When the interval between the TRS symbols is 4 symbols, among symbols to which the SS/PBCH block is mapped, one symbol overlapping the TRS symbol may be. The TRS symbol may not be located consecutively with the SS/PBCH block. In one DRS slot, the SS/PBCH block and the TRS may have a quasi co-location (QCL) relationship.

In the proposed method, the TRS can be multiplexed with an SS/PBCH block in a TDM scheme. To this end, a spacing of TRS symbols and a position of a start TRS symbol among TRS symbols may be changed. For example, the spacing of the TRS symbols may be extended to 5 symbols. In this case, four symbols may exist between TRS symbols, and an SS/PBCH block may be located between TRS symbols. Accordingly, the base station can allocate TRS resources (eg, TRS symbols) before the start symbol of the SS/PBCH block. When the SS/PBCH block occupies from symbol #n to symbol #n+3, the base station may set symbol #n-1 and symbol #n+4 as TRS resources. Here, n may be a natural number of 1 or more. n may be defined in the 3GPP technical standard. The base station may inform the UE of location information (eg, n-1) of the TRS resource through one or more combinations of an RRC message, a MAC control element (CE), and downlink control information (DCI). Alternatively, the terminal may derive the location of the TRS resource based on information obtained through the decoding operation of the SS/PBCH block or RMSI block (eg, the start symbol index (n) of the SS/PBCH block, the physical cell identifier). I can.

7 is a conceptual diagram showing a second embodiment of a TRS arrangement method in a communication system.

Referring to FIG. 7, a TRS may be located at symbol #n-1 and symbol #n+4, and an SS/PBCH block may be located at symbol #n to symbol #n+3 between TRS symbols. . When a symbol before the start symbol of the SS/PBCH block and the symbol after the end symbol of the SS/PBCH block are allocated as TRS resources (eg, TRS symbols), the base station is associated with the corresponding TRS instead of the location information of the TRS resource. SS/PBCH block can be informed to the terminal. When the TRS is associated with the SS/PBCH block, the UE managing the DL using the TRS can obtain time synchronization, frequency synchronization, and assumptions for the preprocessor for demodulation of the corresponding TRS from the SS/PBCH block associated with the TRS. have.

CSI- RS Sending and receiving Triggering (triggering) method

The TRS transmission/reception procedure may be triggered by the base station. The terminal may receive dynamic signaling information (eg, DCI) from the base station for TRS reception. "When the TRS transmission/reception procedure is performed without triggering" or "When the TRS resource is set by DMTC configuration", the antenna port of the TRS may be the same as the antenna port of the triggered CSI-RS, and the TRS is the triggered CSI- It can have a relationship between RS and QCL. The UE may perform a combining operation for TRS irrespective of triggering of the TRS transmission/reception procedure.

The TRS transmission/reception procedure may be triggered by a specific combination between CSI resource setting and CSI report setting. TRS resources may be configured based on CSI-RS resources. In this case, the base station may inform the UE of the characteristics of the TRS resource by using higher layer signaling in the CSI resource setting procedure. The terminal may receive the TRS from the base station and may not report measurement information on the received TRS to the base station. Therefore, the base station can inform the terminal that the measurement reporting operation for a reference signal (eg, TRS) is not required by using higher layer signaling in the CSI resource setting procedure.

The base station may transmit a UL grant including a field for triggering a TRS transmission/reception procedure to the terminal. The UE may receive the UL grant from the base station and may determine whether to transmit the TRS based on a field included in the UL grant. When it is determined that the TRS is transmitted from the base station, the terminal can receive the TRS by performing a monitoring operation on the TRS resource(s), and can estimate the DL based on the received TRS. The UL grant may further include resource allocation information of UL data. The UE can transmit the PUSCH regardless of TRS reception.

The aperiodic transmission/reception procedure of the CSI-RS may be performed without triggering. In this case, the UE may receive the CSI-RS according to the field triggering the CSI report, may generate CSI based on the received CSI-RS, and may report the CSI to the base station. Here, CSI may be mapped to PUSCH. The UL grant may further include resource allocation information of UL data. The UE may transmit the PUSCH regardless of CSI-RS reception.

In order to trigger a CSI-RS transmission/reception procedure or a TRS transmission/reception procedure, the base station may transmit a DCI (eg, UL grant) for each terminal. Therefore, resources required for the PDCCH in the unlicensed band may increase.

In the proposed method, a common DCI for triggering a CSI-RS transmission/reception procedure may be defined. The base station may inform the UEs of a common RNTI using higher layer signaling and may transmit a DCI including information triggering a CSI-RS transmission/reception procedure. The common DCI may follow the DCI format according to the 3GPP technical standard. Alternatively, a new DCI format for common DCI may be introduced. When a new DCI format is introduced, a new RNTI may be introduced.

Common DCI can be constructed by concatenating indices. One index included in the common DCI is information on CSI-RS resources (e.g., information on TRS resources, information on CSI-RS resources for channel quality indicator (CQI) measurement, or CSI-RS resources for RRM measurement) Information). The terminal may perform a monitoring operation on one or more indexes included in the common DCI. The common DCI may be used to trigger a CSI-RS transmission/reception procedure for one or more terminals.

The base station may inform the terminal of the position of the index indicating CSI-RS resource information within the common DCI using higher layer signaling. The base station may inform the terminal of information on a plurality of CSI-RS resources using higher layer signaling. Each of the plurality of CSI-RS resources may be represented by an index. The base station may transmit a common DCI including an index indicating a CSI-RS resource to the terminal. That is, one CSI-RS resource may be indicated to the UE by a combination of higher layer signaling and common DCI. CSI-RS resource information is the index of the CSI-RS resource, the time resource information of the CSI-RS (for example, the index of the CSI-RS symbol when the CSI-RS resource is used as a TRS resource), CSI-RS It may be an orthogonal cover code (OCC), antenna port(s) of CSI-RS, or the like. The CSI-RS symbol may mean a symbol to which CSI-RS is mapped.

8 is a conceptual diagram illustrating a first embodiment of a method for indicating resource information of CSI-RS in a communication system.

Referring to FIG. 8, a payload of DCI may include a plurality of fields, and a specific field (eg, field #1) among a plurality of fields is an index indicating resource information of CSI-RS Can be The base station may inform the UE of the location information of a field (eg, field #1) indicating resource information of the CSI-RS among fields included in the DCI by using higher layer signaling. The UE may check the index indicating resource information of the CSI-RS by performing a monitoring operation in a field indicated by higher layer signaling (eg, field #1) among fields included in the DCI.

In the proposed method, the DCI triggering the CSI-RS transmission/reception procedure may be a DCI scheduling DL transmission. In the embodiments below, DCI scheduling DL transmission may be referred to as DL-DCI, and DCI scheduling UL transmission may be referred to as UL-DCI. When the CSI-RS resource is used as a TRS resource, the UE may not report measurement information of TRS to the base station. Therefore, the CSI-RS transmission/reception procedure may not be triggered by only the UL grant.

In a communication system supporting an unlicensed band, when the base station transmits only CSI-RS in a specific resource region, the CSI-RS transmission operation may violate frequency regulation. Therefore, the base station may not be able to transmit only the CSI-RS in a specific resource region. To solve this problem, the base station may multiplex the CSI-RS with other channels (eg, PDSCH) and/or signals. In order to reduce the size of the PDCCH, it may be desirable that one DCI includes resource allocation information of the PDSCH and resource information of the CSI-RS.

For a rate matching operation for the PDSCH, the UE may consider a field indicating a zero power (ZP) CSI-RS resource among fields included in DCI. That is, the UE may perform a rate matching operation on the PDSCH without considering a field indicating a non-ZP (non-ZP) CSI-RS resource included in the DCI.

DRS How to set up measurement resources

The base station may inform the UE of the resource information of the DRS using higher layer signaling. The resource information of the DRS may include time resource information, frequency resource information, and sequence resource information. In the cell discovery procedure or the initial access procedure, the UE may receive the PBCH and/or PDSCH from the base station, and SS/PBCH based on broadcast information (eg, RMSI or SIB 1) obtained from the PBCH and/or PDSCH. You can check the time resource information of the block.

The terminal may perform an RRM operation for an adjacent base station operating in the same carrier as the serving base station to which the terminal is connected, and may perform a handover operation based on the result of the RRM operation. In a communication system supporting a licensed band, the serving base station transmits physical cell identification information (e.g., physical cell id list, smtc2, pci-List) and measurement location information (periodicityAndOffset) of neighboring base stations using higher layer signaling. I can tell you. The terminal may check the period and offset of the operation of the adjacent base station based on the measurement location information, and may perform demodulation and decoding operations on the SS/PBCH block of the adjacent base station based on the physical cell identification information. Here, the period and offset may be in units of subframes.

In the proposed method, resources of the SS/PBCH block and CSI-RS may be configured in a procedure for setting a DRS measurement object. CSI-RS resources may be used as RRM-RS resources or TRS resources. One SS/PBCH block may be associated with one or more CSI-RS resources. The DRS measurement object includes approximate time resource information (e.g., period and offset in subframe or slot unit) for DRS measurement, a list consisting of SS/PBCH blocks, and one or more CSIs associated with the SS/PBCH block. -May include a list consisting of RS resources.

The subcarrier spacing of the PBCH belonging to the SS/PBCH block may be different from the subcarrier spacing of the CSI-RS resource(s) associated with the SS/PBCH block. In the proposed method, the DRS measurement object may further include information indicating a subcarrier interval of CSI-RS resource(s) related to the SS/PBCH block.

In the proposed method, in order to indicate the measurement of the SS/PBCH block, the DRS measurement object may further include frequency resource information of the SS/PBCH block. The terminal may check the start PRB position of the SS/PBCH block based on the frequency resource information included in the DRS measurement object. In this case, the UE does not need to find the frequency location of the SS/PBCH block even when performing a measurement operation (eg, inter-frequency measurement operation) in another frequency domain. Accordingly, power consumption of the terminal can be reduced.

In the proposed method, in order to set the time resource(s) of the CSI-RS, a measurement period for each of the CSI-RS resources associated with the SS/PBCH block may be set. The measurement period of the CSI-RS may be an integer multiple of the measurement period of the SS/PBCH block. Here, the measurement period may be set in units of subframes or units of slots. The base station may inform the UE of the value (eg, ratio) of the measurement period of the CSI-RS compared to the measurement period of the SS/PBCH block. In one DRS slot, the CSI-RS may be multiplexed with the SS/PBCH block. Alternatively, one DRS slot may include only an SS/PBCH block.

In the proposed method, indexes of resources (eg, symbols) to which CSI-RS is mapped may have a relative value according to the DRS slot. The DRS slot may be a candidate DRS slot in which the UE first detects a DRS resource among candidate DRS slots configured for DRS measurement.

CSI-RS resources may be used as RRM-RS resources or TRS resources. In the proposed method, a field indicating whether the CSI-RS resource is used as an RRM-RS resource or a TRS resource may be defined, and the corresponding field may be included in the DRS measurement object. The field set to the first value may indicate that the CSI-RS resource is an RRM-RS resource. In this case, the UE may interpret the CSI-RS resource as an RRM-RS resource, and may perform an RRM measurement operation based on a reference signal received from the corresponding RRM-RS resource. The field set as the second value may indicate that the CSI-RS resource is a TRS resource. In this case, the UE may interpret the CSI-RS resource as a TRS resource, and may perform DL management based on a reference signal received from the corresponding TRS resource.

The RRM-RS resource may be indicated by the DRS measurement object, and the TRS resource may not be indicated by the DRS measurement object. In this case, it may not be indicated whether the CSI-RS resource is used as an RRM-RS resource or a TRS resource. In the proposed method, the DRS measurement object may include one or more lists, one list may indicate RRM-RS resource(s), and the other list may indicate TRS resource(s). Alternatively, when the DRS measurement object includes only a list indicating RRM-RS resource(s), the list indicating TRS resource(s) may not exist in the DRS measurement object. Resource(s) indicated by one list may be interpreted as RRM-RS resource(s). Alternatively, resource(s) not indicated by the list may be interpreted as RRM-RS resource(s).

CSI-RS resources may be used as RRM-RS resources. In this case, the terminal must be able to know the bandwidth for the RRM measurement operation. In the proposed method, a list indicating CSI-RS resource(s) may include bandwidth information for RRM measurement operation. In the proposed method, a PRB set may be configured in the UE, and the UE may derive a PRB to which CSI-RS resources are mapped. The PRB set may include all PRBs belonging to the bandwidth of the BWP. The base station may inform the UE of the PRB set using higher layer signaling. In this case, the base station may omit the setting operation of the bandwidth for the RRM measurement operation.

When the CSI-RS resource overlaps the SS/PBCH block in a specific PRB, the CSI-RS resource overlapping the SS/PBCH block may not be used for CSI-RS transmission. In the proposed method, the base station may inform the UE of the frequency resource information of the CSI-RS using higher layer signaling. When the CSI-RS is multiplexed with the SS/PBCH block and FDM scheme (e.g., FIGS. 5A and 5B), the base station informs the terminal of the start PRB and/or the end PRB of the CSI-RS using higher layer signaling. I can.

When the SS/PBCH block is located at the edge of the BWP and the CSI-RS is multiplexed with the SS/PBCH block in the FDM scheme, the CSI-RS may not overlap the SS/PBCH block in the frequency domain. The base station may inform the UE of the mapping information of the CSI-RS using higher layer signaling. When the CSI-RS is multiplexed by the SS/PBCH block and the TDM scheme, the base station may inform the terminal of the start PRB and the end PRB of the CSI-RS using higher layer signaling. In the proposed method, the frequency resource of the CSI-RS may be indicated as the frequency resource of the BWP. CSI-RS may be mapped to a PRB belonging to the reference BWP. The reference BWP may be firstActiveDownlinkBWP, defaultDownlinkBWP, initialDownlinkBWP, or a BWP last activated by the base station.

The base station can change the BWP. In this case, the terminal may perform the BWP change procedure using a preset time (eg, a radio frequency (RF) re-tuning delay time). After the BWP change procedure is completed, the UE may perform a CSI-RS measurement operation in the changed BWP. When a preset time (eg, inactivity timer) has expired, the BWP may be changed to defaultDownlinkBWP. In this case, the UE may perform a CSI-RS measurement operation in the changed BWP.

The base station may fix the reference BWP to one BWP so that a plurality of terminals can commonly perform the CSI-RS measurement operation. For example, it may be allowed for the UE to perform a measurement operation using the CSI-RS set in initialDownlinkBWP. The base station may instruct the terminal to perform the measurement operation of the CSI-RS in the same BWP as the BWP of the PDSCH and/or the CORESET through which the RMSI is transmitted. The UE may assume that the BWP to which the CSI-RS is mapped is initialDownlinkBWP without separate signaling from the base station.

The UE may perform a CSI-RS measurement operation and a PDSCH decoding operation. For example, the measurement operation of the CSI-RS may be performed simultaneously with the decoding operation of the PDSCH. In this case, the UE may assume that the BWP to which the CSI-RS belongs is the same as the BWP to which the PDSCH belongs. In order to receive the CSI-RS and PDSCH within a preset time, the UE may assume that the BWP to which the CSI-RS belongs is the same as the BWP to which the PDSCH belongs. Here, the BWP of the CSI-RS and PDSCH may be initialDownlinkBWP. When a CSI-RS exists before or after the PDSCH, the base station may configure the BWP to which the PDSCH belongs to the same BWP to which the CSI-RS belongs. The BWP to which the PDSCH belongs may be set differently from the BWP to which the CSI-RS belongs. In this case, the terminal may receive the PDSCH in the most recently changed BWP. Here, the UE may not be able to receive the CSI-RS in the BWP to which the PDSCH belongs.

The base station may not inform the terminal of the BWP. In this case, the UE may derive the PRB to which the CSI-RS is mapped based on the CORESET for detection of the type 0 PDCCH common search space (CSS). The UE may assume that the CSI-RS is mapped to all the PRBs consecutive between the start PRB and the end PRB to which the CORESET is mapped.

DMTC First Example

The DRS measurement object may be defined as shown in Table 1 below.

DRS measurement configuration information may include an indicator indicating the location of the DRS slot, a list indicating resources of the SS/PBCH block, and the like. The location of the DRS slot may be expressed so that the UE can receive the SS/PBCH block. The UE may know the candidate subframe(s) and/or the candidate slot(s) capable of receiving DRS based on the indicator indicating the location of the DRS slot.

The list indicating resources of the SS/PBCH block may include time resource information of the SS/PBCH block, a list indicating CSI-RS resources, and a subcarrier interval of CSI-RS resources. In addition, the list indicating resources of the SS/PBCH block may further include frequency resource information of the SS/PBCH block.

The list indicating CSI-RS resources may include time resource information of CSI-RS. The time resource information of the CSI-RS may indicate the length from the slot in which the SS/PBCH block was received (eg, the last symbol of the SS/PBCH block) to the CSI-RS symbol. The list indicating CSI-RS resources may further include a period of CSI-RS resources (eg, a measurement period of CSI-RS). The period of the CSI-RS resource may be an integer multiple of the period of the SS/PBCH block. The list indicating CSI-RS resources may further include information indicating the purpose of the CSI-RS (eg, RRM measurement or DL management). Information indicating the use of the CSI-RS may be omitted from the list indicating the CSI-RS resources. In this case, the CSI-RS indicated by the list can be used only for the RRM measurement operation.

DRS Second Example

The DRS measurement object may be defined as shown in Table 2 below. The CSI-RS resource configuration method according to Table 2 may be different from the CSI-RS resource configuration method according to Table 1.

The DRS measurement object may include a list indicating CSI-RS resources, and the list indicating CSI-RS resources may include a subcarrier interval of CSI-RS resources. The DRS measurement object may include one or more lists. "When CSI-RS resources are indicated by one list" or "When CSI-RS resources are not indicated by a list", the UE uses CSI-RS resources or all CSI-RS resources indicated by the list. Can be used to perform the RRM measurement operation. There may be two lists indicating CSI-RS resources. In this case, the UE may perform an RRM measurement operation based on CSI-RS resources belonging to the first list, and may perform a DL management operation based on CSI-RS resources belonging to the second list.

PDSCH Rate Matching action

Data may be transmitted through the DRS slot. The base station may transmit broadcast information (eg, system information, paging information, etc.), and may transmit data (eg, unicast data) for a specific terminal. The base station may transmit DRS and DCI in one DRS slot, and may transmit data based on a dynamic scheduling scheme. CORESET can be set in the DRS slot. The UE can detect a DL control channel (eg, PDCCH) by performing a monitoring operation in CORESET, obtain DCI from the DL channel channel, and obtain PDSCH resource allocation information from DCI. Here, DCI (eg, CRC of DCI) may be scrambled by RNTI. When DCI is transmitted to a specific terminal, DCI (eg, CRC of DCI) may be scrambled by C-RNTI, MCS-C-RNTI, or CS-RNTI. When DCI is transmitted to unspecified terminals, DCI (eg, CRC of DCI) may be scrambled by P-RNTI, SI-RNTI, RA-RNTI, or TC (temporary cell)-RNTI.

A terminal performing a cell search procedure or an initial access procedure may perform a decoding operation on PDSCH-1_0 based on DCI-1_0. The base station and the terminal may share the RE mapping rule of PDSCH-1_0 in advance. "When the SS/PBCH block is mapped to the resource area of PDSCH-1_0" or "When a specific CORESET exists in the resource area of PDSCH-1_0", PDSCH-1_0 refers to the corresponding resource area (eg, SS/PBCH block Or, it may not be mapped to REs where CORESET is located. When the base station allocates PDSCH-1_1, the UE may know the location of the CSI-RS resource (eg, NZP CSI-RS resource and ZP CSI-RS resource) in RE units. In this case, PDSCH-1_1 may be rate matched to REs excluding CSI-RS resources in the resource region.

In the NZP CSI-RS resource, the base station may transmit the CSI-RS to the terminal using a specific power. That is, the NZP CSI-RS resource may be used for CSI-RS transmission. CSI-RS may not be actually transmitted in the ZP CSI-RS resource. The base station may not map the PDSCH to the ZP CSI-RS resource. The ZP CSI-RS resource may be used in the UE to distinguish between an RE to which PDSCH is mapped and an RE to which PDSCH is not mapped. The ZP CSI-RS resource may be used for purposes other than PDSCH transmission. For example, the ZP CSI-RS resource may be used as an RRM-RS resource or a TRS resource.

Since DCI-1_0 includes resource allocation information of broadcast information for a terminal performing an access procedure or an unspecified terminal, the terminal cannot dynamically determine the location of the CSI-RS resource based on the DCI-1_0 received from the base station. . That is, the base station cannot indicate a CSI-RS resource allocated to a specific terminal by using DCI-1_0.

In the following embodiments, methods of adjusting the coding rate of the PDSCH (eg, PDSCH-1_0) allocated by DCI-1_0 will be described. The terminal may operate in an RRC connected state, an RRC inactive state, or an RRC idle state. DCI-1_0 may include resource allocation information of PDSCH-1_0, and DCI-1-1 may include resource allocation information of PDSCH-1_1. In the RE mapping procedure of PDSCH-1_0, the UE may consider an RE to which PDSCH-1_0 is not mapped as a ZP resource. In the RE mapping procedure of PDSCH-1_1, the UE may consider an RE to which PDSCH-1_1 is not mapped as a ZP resource. The UE may determine that the PDSCH (eg, PDSCH-1_0, PDSCH-1_1) is not mapped in the ZP resource, and may perform demodulation and decoding operations on data.

In the proposed method, the PDSCH may not be mapped to ZP resources (eg, REs) as well as REs to which the SS/PBCH block is mapped. The UE may determine that PDSCH-1_0 and PDSCH-1_1 are not mapped to ZP resources (eg, REs). The UE may select only REs to which PDSCH-1_0 is mapped.

A terminal that does not operate in the RRC connected state may check the location of the ZP resource based on the master information block (MIB), information derived from the MIB, SSS, and PSS. The terminal can check the ZP resource in RE units. Here, the MIB may include information indicating ZP resources in RE units. Alternatively, the ZP resource may be derived in RE units based on “synchronization signal (eg, SSS, PSS)” or “information inferred by synchronization signal and SS/PBCH block index”. The above information may be confirmed by an unspecified terminal that does not operate in the RRC connected state. The above-described operation may be applied to "when the base station allocates cell-specific ZP resources and maps PDSCH-1_0 based on the ZP resources".

In the proposed method, the PDSCH may not be mapped not only to the symbol where the SS/PBCH block is located, but also the symbol where the CSI-RS is located. Accordingly, the code rate adjustment operation for PDSCH-1_0 may be performed differently from the code rate adjustment operation for PDSCH-1_1. Since the UE can know the ZP resource associated with PDSCH-1_1 in RE units, it is possible to perform a decoding operation on REs to which PDSCH-1_1 is mapped. Since the UE can know the ZP resource associated with PDSCH-1_0 in symbol units, it is possible to perform a decoding operation on symbols to which PDSCH-1_0 is mapped. A method of allocating a cell-specific ZP resource may be applied in order to inform the ZP resources in symbol units to terminals not operating in the RRC connected state.

PDSCH Puncture (puncturing) method

The terminal may not be able to receive information on the ZP resource from the base station. In this case, the UE may perform a puncturing operation to receive the PDSCH. The base station may map the PDSCH to resources (eg, REs) allocated by DCI without consideration of the REs to which the CSI-RS is mapped. In addition, the base station may map the CSI-RS to preset resources (eg, REs) without consideration of the REs to which the PDSCH is mapped. To implement the above-described method, the base station may first map the PDSCH to a resource grid, and then perform a CSI-RS mapping operation thereafter. When the PDSCH is mapped to the RE to which the CSI-RS is to be mapped, the base station may map the CSI-RS to the corresponding RE instead of the PDSCH.

The UE that wants to receive the CSI-RS can know the REs to which the CSI-RS is mapped based on a preset position of the CSI-RS regardless of the RE mapping of the PDSCH. A UE wishing to receive the PDSCH may not know the CSI-RS resource. In this case, the CSI-RS mapped to the PDSCH RE (eg, RE belonging to the resource region of the PDSCH) may be transmitted from the UE to the decoder for the PDSCH. That is, the UE may regard the CSI-RS mapped to the PDSCH RE as the PDSCH. This terminal operation can be predicted by the base station. Accordingly, the base station can adjust the modulation and coding scheme (MCS) level of the PDSCH so that the target error rate can be obtained in the terminal.

The UE may know the resource information of the CSI-RS, and may perform a decoding operation on the PDSCH based on the resource information of the CSI-RS. In this case, the PDSCH may not be mapped to REs occupied by the CSI-RS. In the PDSCH decoding procedure, the input value of the CSI-RS mapped to the PDSCH RE (eg, the input value of the decoder for the PDSCH) may be adjusted. For example, in the PDSCH decoding procedure, a probability value for a CSI-RS mapped to a PDSCH RE (eg, a detection probability for a code bit, a log likelihood ratio (LLR), a soft bit) may not be derived. In this case, the probability that the CSI-RS mapped to the PDSCH RE is 1 may be regarded as the same as the probability that the CSI-RS mapped to the PDSCH RE is 0.

Cell/ BWP certain ZP How to set up resources

In the proposed method, information on a ZP resource (eg, a ZP CSI-RS resource) may be expressed as information on a cell or a sector. The ZP CSI-RS resource may mean REs to which PDSCH-1_0 or PDSCH-1_1 is not mapped. Terminals that do not operate in the RRC connected state (eg, unspecified terminals) can find the location of the ZP resource from a function of a cell or a BWP. For example, the terminal may check the location of the ZP resource based on information derived from the physical cell identification information. ZP resources may include time resources and frequency resources, and may be expressed in RE units. Alternatively, the ZP resource may be expressed in units of symbols.

In the proposed method, the UE determines the location of the ZP resource using "the index of the SS/PBCH block", "physical cell identification information", or "information inferred by the physical cell identification information and the SS/PBCH block index". I can confirm. Here, the ZP resource may be expressed in RE units or symbol units. The UE may obtain physical cell identification information for the SS/PBCH block through demodulation/decoding operation for the SS/PBCH block or higher layer signaling of the base station. In this case, the terminal can check the location of the ZP resource regardless of the RRC operation state. That is, even an unspecified terminal can know the location of the ZP resource. The base station may not explicitly indicate the location of the RE or symbol to which PDSCH-1_0 is mapped. Even in this case, unspecified UEs can know the location of the RE or symbol to which PDSCH-1_0 is mapped. PDSCH-1_0 may be dynamically allocated by DCI-1_0 scrambled by P-RNTI, RA-RNTI, TC-RNTI, SI-RNTI, C-RNTI, MCS-C-RNTI, or CS-RNTI.

When the ZP resource is used as an RRM-RS resource, the location of the time resource (eg, ZP symbol) of the ZP is "SS/PBCH block index", "physical cell identification information", or "physical cell identification information and It may be derived based on "information inferred by the index of the SS/PBCH block". When the ZP resource is used as an RRM-RS resource, the location of the frequency resource (eg, subcarrier) of the ZP is inferred by “physical cell identification information” or “physical cell identification information and the index of the SS/PBCH block. It may be the remainder obtained by dividing a value derived based on "information" by a preset value (eg, 4). A terminal that does not operate in the RRC connected state can know the RRM-RS resource in units of REs or symbols by combining the above-described information.

When the ZP resource is used as the RRM-RS resource, the UE may assume that the frequency band occupied by the RRM-RS resource spans the entire carrier. Alternatively, the UE may assume that the frequency band occupied by the RRM-RS resource is valid in the LBT subband. The UE may detect REs to which PDSCH-1_0 is mapped based on the above-described assumption. The LBT subband may include one or more resource blocks (RBs).

When the ZP resource is used as a TRS resource, the location of the time resource (eg, symbol) of the ZP is “the index of the SS/PBCH block”, “the physical cell identification information”, or “the physical cell identification information and the SS/PBCH It can be derived based on the information inferred by the index of the block. When the ZP resource is used as a TRS resource, the location of the frequency resource (eg, subcarrier) of the ZP is “physical cell identification information” or “information inferred by the physical cell identification information and the SS/PBCH block index” It may be the remainder obtained by dividing a value derived based on a predetermined value (eg, 4). A terminal that does not operate in the RRC connected state may know the TRS resource in RE units or symbol units by combining the above-described information.

When the ZP resource is used as a TRS resource, the UE may assume that the frequency band occupied by the TRS resource is located in the entire carrier. The UE may detect the RE to which PDSCH-1_0 is mapped based on the above-described assumption.

DL SPS (semi persistent scheduling) setting and HARQ (hybrid automatic repeat request) response

The DL SPS information may be indicated to the terminal through upper layer signaling as well as physical layer signaling. Information indicated to the terminal by higher layer signaling (eg, RRC message) may be distinguished from information indicated to the terminal by physical layer signaling (eg, DCI). In the following embodiments, the SPS PDSCH may be a PDSCH scheduled by DL SPS information.

The RRC message includes a reception period (eg, transmission period) of the SPS PDSCH, the number of HARQ processes (eg, the maximum number) of the SPS PDSCH, and a physical uplink control (PUCCH) used for transmitting a HARQ response for the SPS PDSCH. channel), the MCS table for the SPS PDSCH, and the like. The reception period of the SPS PDSCH may be 10 ms to 640 ms. The number of HARQ processes (eg, the maximum number) of the SPS PDSCH may be 8. The MCS table may be an MCS table defining up to 64QAM (quadrature amplitude modulation) or an MCS table defining up to 256QAM. In addition, the base station may inform the UE of the CS-RNTI. CS-RNTI may be used for scrambling of PHY messages (eg, DL-DCI).

DL-DCI format 1_0 is a frequency domain PRB allocation information, PDSCH time resource information, VRB (virtual resource block)-to-PRB (physical resource block) mapping information, MCS, NDI (new data indicator), RV (redundancy version) ), HARQ process index, downlink assignment index (DAI), transmission power control (TPC) for PUCCH, PRI (eg, resource index of UL control channel), slot offset for feedback of HARQ response, etc. have.

The DL-DCI format 1_1 may include one or more pieces of information included in the DL-DCI format 1_0. In addition, the DL-DCI format 1_1 may further include a BWP index, a carrier index, an indicator of a PRB bundling size, a rate matching indicator, a ZP CSI-RS trigger, and the like. The transmission slot of the SPS PDSCH may be periodically generated based on the slot in which the DL-DCI for initializing or resetting the SPS PDSCH is received.

If the DL-DCI is scrambled by CS-RNTI and the NDI is 1, the UE may determine that the retransmission operation for the HARQ process indicated in the corresponding DL-DCI is performed. If the DL-DCI is scrambled by CS-RNTI and NDI is 0, the UE may determine that the initial transmission operation or reconfiguration operation for the HARQ process indicated in the corresponding DL-DCI is performed.

MCS-CS-RNTI may be introduced for SPS for URLLC PDSCH. The URLLC PDSCH may be a PDSCH that satisfies the requirements of the URLLC service.

How to set the frequency position of the resource grid

The UL grant scheduling PUSCH may be transmitted to the terminal through a PDCCH or RRC message. The UL grant may include a bitmap for indicating the frequency resource of the PUSCH. The UE may check the index of the LBT subband based on the bitmap included in the UL grant. The terminal may perform an LBT operation in the LBT subband indicated by the base station. If the LBT operation is successful, the UE may transmit the PUSCH in the corresponding LBT subband. The index of the PUSCH interlace may be indicated by a bitmap. The PUSCH interlace may indicate PUSCH resources in the frequency domain. For example, one PUSCH interlace may include one or more physical resource blocks (PRBs).

One point A may exist in the unlicensed band. When the unlicensed band includes a plurality of LBT subbands, a common resource block (CRB) applied to the LBT subband located in the middle of the unlicensed band may have a large offsetToPointA . When the LBT operation is successful in adjacent LBT subbands, the UE may map the PUSCH to PRBs located at the boundary of the adjacent LBT subbands.

Frequency resources of the PUSCH may be allocated by the UL grant, and frequency resources of the PUSCH allocated by the UL grant may be located in LBT subbands #1 and #2. In this case, the UE may use LBT subband #1 and/or #2 according to the result of the LBT operation. The UE may perform a PUSCH mapping operation according to the PUSCH interlaces of LBT subbands #1 and #2. The PUSCH interlace may be indicated by a bitmap included in the UL grant.

For example, there may be four LBT subbands, and points Ai and Bi for each of the four LBT subbands may be defined. Here, i may be 1, 2, 3, or 4. Carriers for the activated broadband BWP may be indicated by point A (eg, point A1) and point B (eg, point B4). The PUSCH may be mapped to the PUSCH interlace based on point A for each LBT subband.

The resource grid in each of the LBT subbands may be defined based on point A. In one LBT subband, a carrier (eg, BWP) of the first terminal may be set. A carrier (eg, BWP) of the second terminal may be set in a plurality of LBT subbands. In this case, the BWP of the first terminal (eg, one LBT subband) may be multiplexed with the BWP of the second terminal (eg, a plurality of LBT subbands) in the frequency domain.

The starting point of the PUSCH interlace in one LBT subband (eg, activated BWP) may be derived from the point A of the corresponding LBT subband. PUSCH interlaces may belong to different BWPs. Even in this case, in order for the base station to multiplex the terminals in the frequency domain, the corresponding PUSCH interlaces may have the same starting point. That is, PUSCH interlaces may start in the same subcarrier. To this end, the base station may set a BWP (eg, a carrier) such that PUSCH interlaces have the same starting point (eg, PRB), and may activate the corresponding BWP.

The base station may not multiplex the terminals in the frequency domain. In this case, the resource grids in BWPs may not match. When the time multiplexing scheme is used, the base station can use the channel occupancy time (COT) secured by the LBT operation. In addition, the size of the MCOT (maximum COT) may be limited by frequency regulation.

Transmission method of the COT indicator

The base station can transmit a DL signal and/or a DL channel by performing an LBT operation. The UE may transmit a UL signal and/or a UL channel by performing an LBT operation. LBT operation may be performed according to a delay time (defer time) according to the LBT category. When a category 2 LBT (hereinafter referred to as "C2 LBT") is used, each of the base station and the terminal may perform an LBT operation during a fixed time T (eg, 16 μs or 25 μs) in the LBT partial band. . When the result of the LBT operation (eg, received signal strength) is less than or equal to the threshold value, each of the base station and the terminal may determine that a signal and/or a channel can be transmitted in the corresponding LBT subband.

When category 4 LBT (hereinafter referred to as "C4 LBT") is used, each of the base station and the terminal has a delay time based on a random variable selected within a channel access priority class (CAPC) (p) and a contention window. Can be determined, and LBT operation can be performed during the delay time. The random variable may be a value randomly selected within a range (eg, 0, …, L-1) smaller than the size L of the contention window. When the result of the LBT operation (eg, received signal strength) is less than or equal to the threshold value, each of the base station and the terminal may determine that a signal and/or a channel can be transmitted in the corresponding LBT subband. When the result of the LBT operation (eg, received signal strength) exceeds the threshold value, each of the base station and the terminal may stop a random backoff procedure. When it is determined that the LBT partial band is in the idle state, each of the base station and the terminal may resume the stopped random backoff procedure.

The COT indicator may be included in the group common DCI. The group common DCI including the COT indicator may be transmitted in a common search space (CSS) of CORESET. One or more PDCCH candidates may exist in CSS. The scrambling sequence of the group common DCI including the COT indicator may be commonly applied to unspecified terminals. The base station may set the RNTI used for scrambling of the group common DCI including the COT indicator to a plurality of terminals using higher layer signaling. The terminal may perform a descrambling operation for the group common DCI including the COT indicator using the RNTI set by the base station.

Frequency resource to which the COT indicator is applied

The COT indicator can be transmitted per CORESET. For example, the terminal may perform a monitoring operation for CORESET in a DL BWP set within a plurality of LBT subbands. When CORESET is defined for each LBT partial band, the terminal may detect the COT indicator by performing a monitoring operation for a plurality of CORESETs. In the proposed method, one COT indicator may indicate a frequency resource structure for one or more LBT subbands or one or more carriers. When a plurality of COT indicators are received, the UE can expect that each of the plurality of COT indicators indicate matched information for the same LBT subband or the same carrier.

The terminal may not perform a descrambling operation for DCI including the COT indicator. In this case, the terminal may determine that the LBT operation performed by the base station is successful based on the CORESET DM (demodulation)-RS. Alternatively, the terminal may determine that the LBT operation performed by the base station has not been successful. The CORESET DM-RS may be a DM-RS located in the CORESET. The terminal may determine whether to perform a monitoring operation for a CORESET set in another LBT subband based on the COT indicator.

The base station may perform an LBT operation for each LBT subband. When the LBT operation is successful, the base station may transmit a DL signal and/or a DL channel in the corresponding LBT subband. After performing the LBT operation, the base station may determine the frequency resource structure of one or more LBT subbands occupied by the resources allocated by the base station. Sufficient time may be required in the base station for the transmission operation of the COT indicator (eg, generation of the COT indicator, mapping the COT indicator to the PDCCH, transmission of the PDCCH). If sufficient time is not secured for the transmission operation of the COT indicator, the base station may not transmit the COT indicator.

In the proposed method, one COT indicator may indicate a frequency resource structure for one or more LBT subbands or one or more carriers. When a plurality of COT indicators are received, the terminal may determine that each of the plurality of COT indicators indicates different information for the same LBT partial band or the same carrier. The terminal may determine that the LBT operation has been successful in the base station by performing a descrambling operation for DCI (eg, CRC of DCI) including the COT indicator.

The COT indicator may include information indicating the LBT subband or carrier on which the LBT operation is successful. If sufficient time is not secured for the transmission operation of the COT indicator, the base station may transmit a different COT indicator for each LBT subband. The base station may transmit the DCI including the COT indicator through the CORESET set for each LBT partial band. DCI (eg, COT indicator) transmitted in a specific LBT subband may not include information on other LBT subbands.

When sufficient time is secured for the transmission operation of the COT indicator, information of the time resource structure commonly applied in the LBT subbands (eg, slot pattern) and information of the LBT subband(s) in which the LBT operation is successful ( For example, a COT indicator including a pattern) may be transmitted in all LBT subbands. When sufficient time is not secured for the transmission operation of the COT indicator, information on the frequency resource structure of the COT may be defined as a separate value. The COT indicator of each of the LBT subbands may include information on the corresponding LBT subband.

A method of indicating the same slot structure using multiple COT indicators

CORESET to which the COT indicator is transmitted may be located in the first part (eg, symbol) of the slot. CORESET may not be located after the third symbol of the slot. The number of consecutive symbols to which CORESET is mapped may not be greater than 3. In addition, CORESET may be located after the second symbol or the second symbol of the slot.

The COT indicator may indicate the location of the DL resource in one or more slots. The location of the DL resource indicated by the COT indicator may be valid in one or more LBT subbands. The effective LBT subband(s) may be determined based on the information of the frequency resource structure included in the COT indicator. The COT indicator may include information indicating one or more valid slots. A plurality of COT indicators may indicate a time resource structure and a frequency resource structure of one slot.

9 is a conceptual diagram illustrating a first embodiment of a method for mapping a COT indicator in a communication system.

Referring to FIG. 9, the base station may acquire a COT including 6 slots (eg, slots #0 to #5) by performing an LBT operation. The DCI including the COT indicator (eg, group common DCI) may be transmitted in units of two slots. For example, the DCI including the COT indicator may be transmitted in slot #0, slot #2, and slot #4. The DCI including the COT indicator may be transmitted in the front region of the slot. DCI including the COT indicator may not be transmitted in the first symbol of the slot. The COT indicator may include information (eg, structure information) on a plurality of slots. The slot information may be indicated by a plurality of COT indicators.

Information of slot #2 may be indicated by a COT indicator received in slot #0 and a COT indicator received in slot #2. Information of slot #4 may be indicated by a COT indicator received in slot #2 and a COT indicator received in slot #4. When information on a specific slot is indicated by different COT indicators, slot information indicated by different COT indicators may be the same or different. In the proposed method, when information on a specific slot is indicated by different COT indicators, the UE may regard the slot information indicated by different COT indicators as the same.

In the proposed method, when information of a specific slot is indicated by different COT indicators, the terminal can check information of a specific slot according to the last received COT indicator among the different COT indicators. The COT indicator received in slot #0 may indicate a valid structure in slots #0 to #2. The COT indicator received in slot #2 may indicate a valid structure in slots #2 to #4. The COT indicator received in slot #4 may indicate a valid structure in slots #4 and #5. In this case, the terminal may check the structure of slot #2 based on the COT indicator received in slot #2, and may check the structure of slot #4 based on the COT indicator received in slot #4.

In the proposed method, when information on a specific slot is indicated by a plurality of COT indicators, information on a specific slot included in the plurality of COT indicators may be the same. Among the terminals, some terminals may perform a discontinuous reception (DRX) operation to save power. When information on a specific slot is indicated by a plurality of COT indicators, the terminal may use the unupdated slot information. To solve this problem, the base station can transmit the same information for one slot.

Even when a structure of a plurality of slots is indicated by a combination of indexes, a structure of one slot may have the same pattern. When the structure information of all slots is obtained within a time set by the base station (eg, COT), the terminal may not perform a decoding operation of the COT indicator. The slot structure indicated by the COT indicator may not be changed. The terminal may not perform the decoding operation of the COT indicator multiple times.

Meanwhile, some or all of the slot structure indicated by the COT indicator may be overridden. In the proposed method, a plurality of COT indicators may indicate the same information for some structures of the same slot, and information of the remaining structures of the same slot may be overridden. In one LBT subband, there may be resources that cannot be overridden (eg, DL resources) and resources that can be overridden (eg, flexible) resources. The first COT indicator may indicate an overridable resource(s), and the resource(s) indicated by the first COT indicator may be overridden. In this case, the second COT indicator after the first COT indicator may override the resource(s) set by the first COT indicator.

In the proposed method, when information (eg, structure information) of a specific slot is indicated by a plurality of COT indicators, information on a specific slot included in the plurality of COT indicators may be different from each other. In this case, the terminal may check the slot structure (eg, the structure of the time and frequency resources of the slot) based on the last received COT indicator among the plurality of COT indicators. Among the plurality of COT indicators, the structure information of the slot indicated by the COT indicator first received in the time domain may be overridden. The base station may change the information indicated by the COT indicator to dynamically respond to the traffic situation. In this case, it may be desirable for the terminal to receive all COT indicators.

Containing COT indicator DCI How not to be transmitted in the first slot

If sufficient time is not secured for the transmission operation of the COT indicator, the base station may not be able to transmit the DCI (eg, group common DCI) including the COT indicator in the first slot in the COT.

10 is a conceptual diagram illustrating a second embodiment of a method for mapping a COT indicator in a communication system.

Referring to FIG. 10, the base station may acquire a COT including 6 slots (eg, slots #0 to #5) by performing an LBT operation. The base station may not be able to transmit the DCI including the COT indicator in the first slot (eg, slot #0) in the COT. The DCI including the COT indicator may be transmitted through slot #1, slot #3, and slot #5. That is, the UE can receive DCI in each of slot #1, slot #3, and slot #5, and can check the COT indicator included in the DCI.

Structure information of slot #0 may not be transmitted. The COT indicator may include structure information of two slots. The COT indicator received in slot #n may include structure information of slots #n and #n+1. n may be an integer greater than or equal to 0. The period of CORESET and search space set in the terminal may be two slots. The COT indicator received in slot #5, the last slot of the COT, may include structure information of one slot (eg, slot #5).

The terminal may determine the timing of application of the pattern of the slot indicated by the COT indicator and the pattern of the LBT partial band(s) (eg, the pattern of the carrier(s)). The terminal may apply the information indicated by the COT indicator from the slot in which the COT indicator is received. The base station may transmit a different COT indicator for each LBT subband or carrier. In this case, different slot patterns for the same LBT subband or the same carrier may be indicated to the UE. Accordingly, the terminal may not be able to interpret the pattern of the specific slot(s) indicated by the COT indicator.

In the proposed method, the base station may explicitly inform the terminal of the time when the COT indicator is applied (eg, a start slot to which the COT indicator is applied). The base station may inform the terminal of information indicating the application time of the COT indicator using higher layer signaling. When the application point indicated by higher layer signaling is set to the first value, the terminal may apply the slot pattern indicated by the corresponding COT indicator from the slot in which the COT indicator is received. When the application time indicated by higher layer signaling is set to the second value, the terminal may apply the slot pattern indicated by the corresponding COT indicator in k slot(s) after the slot in which the COT indicator was received. . k may be set in the terminal through higher layer signaling.

The base station may not set the application time and/or k of the COT indicator. The base station may transmit to the terminal an index that comprehensively indicates a pattern of a plurality of slots. When a specific field in the COT indicator has a first value, the index set in the terminal may be applied from the slot in which the COT indicator is received. When a specific field in the COT indicator has a second value, the index set in the terminal may be applied from a slot in which the COT indicator is received and from a slot after k slot(s). k may be set in the terminal through higher layer signaling. Alternatively, k may be defined in the 3GPP technical standard. For example, k may be 1 or more.

11 is a conceptual diagram showing a third embodiment of a method for mapping a COT indicator in a communication system.

Referring to FIG. 11, the base station may acquire a COT including 6 slots (eg, slots #0 to #5) by performing an LBT operation. The base station may not be able to transmit the DCI including the COT indicator in the first slot (eg, slot #0) in the COT. The base station may transmit DCI including the COT indicator in slot #1, slot #3, and slot #5. That is, the DCI including the COT indicator may be transmitted in units of two slots.

The COT indicator may include structure information of two slots. The COT indicator included in the DCI transmitted in slot #1 may include structure information of slots #2 and #3. The COT indicator included in the DCI transmitted in slot #3 may include structure information of slots #4 and #5. The COT indicator included in the DCI transmitted in slot #5 may include structure information of slots #6 and #7. Since slots #6 and #7 are not included in the COT, the terminal may not receive DCI in slot #5. The UE may receive DCI by performing a monitoring operation in each CORESET (eg, a search space) of slot #1 and slot #3, and may obtain a COT indicator included in the DCI.

In the proposed method, the base station may explicitly inform the UE of the time when the COT indicator is applied (eg, a start slot to which the COT indicator is applied). The base station may inform the terminal of an index that comprehensively indicates patterns of a plurality of slots. When a specific field in the COT indicator has a first value, the index set in the terminal may be applied from a slot in which the information indicated by the COT indicator is received. When a specific field in the COT indicator has a second value, the index set in the terminal may be applied from a slot in which the information indicated by the COT indicator is received from a slot before k slot(s) from which the COT indicator is received. k may be set in the terminal through higher layer signaling. Alternatively, k may be defined in the 3GPP technical standard. For example, k may be 1 or more.

12 is a conceptual diagram showing a fourth embodiment of a method for mapping a COT indicator in a communication system.

Referring to FIG. 12, the base station may acquire a COT including 8 slots (eg, slot #0 to slot #7) by performing an LBT operation. If sufficient time is not secured for the transmission operation of the COT indicator, the base station may not be able to transmit the DCI including the COT indicator in the first slot (eg, slot #0) in the COT. Accordingly, the base station can transmit DCI including the COT indicator in slot #1, slot #3, slot #5, and slot #7. The DCI including the COT indicator may be transmitted in units of two slots. The period of CORESET (eg, search space) set in the terminal may be two slots.

The COT indicator included in the DCI transmitted in slot #1 may include structure information of slots #0 to #3. A specific field included in the COT indicator may indicate that the application time of the corresponding COT indicator is a slot (eg, slot #0) prior to slot #1 in which the corresponding COT indicator is transmitted. The COT indicator included in the DCI transmitted in slot #3 may include structure information of slots #3 to #6. A specific field included in the COT indicator may indicate that the application time of the corresponding COT indicator is slot #3 in which the corresponding COT indicator is transmitted.

The COT indicator included in the DCI transmitted in slot #5 may include structure information of slots #5 to #7. A specific field included in the COT indicator may indicate that the application time of the corresponding COT indicator is slot #5 in which the corresponding COT indicator is transmitted. Since the COT indicator included in the DCI transmitted in slot #7 includes the structure information of the slot(s) after the COT, the terminal may not receive the DCI in slot #7. The UE may receive DCI by performing a monitoring operation in each CORESET (eg, a search space) of slot #1, slot #3, and slot #5, and may obtain a COT indicator included in the DCI.

Method for changing the number of valid slots indicated by the COT indicator

The base station may transmit information necessary for reception of the COT indicator to the terminal using higher layer signaling. The terminal may acquire information necessary for reception of the COT indicator through higher layer signaling. Information necessary for reception of the COT indicator may include information indicating a period of a CORESET and/or a search space. The terminal may receive the DCI including the COT indicator in the slot(s) (eg, COT) secured by the base station. The COT may include information on the time resource structure (eg, the format of the slot) and frequency resource structure (eg, the number of LBT subbands) of the slot(s) secured by the base station.

The number of slots included in the COT secured by the base station may be less than or equal to a preset maximum number. The maximum number of slots included in the COT may be determined according to frequency regulation and an access class (eg, CAPC) of LBT operation. The transmission period of the COT indicator may be the same as the period of CORESET and/or the search space. The number of slots included in the COT secured by the base station may not be divided by the number of slots corresponding to the transmission period of the COT indicator.

In the proposed method, the COT indicator may include information indicating the number of valid slots to which the information indicated by the corresponding COT indicator is applied. A specific field included in the COT indicator may indicate the number of valid slots in the form of an index. The COT indicator may indicate the end point of the COT (eg, slot index, number of slots, mini slot index, number of mini slots).

The base station may inform the terminal that the index included in the COT indicator indicates the structure of N or more slots using higher layer signaling. N may be an integer of 1 or more. N slots indicated by the COT indicator may be included in the COT secured by the base station. Alternatively, one or more of the N slots indicated by the COT indicator may be located before or after the COT secured by the base station.

The COT indicator may be applied to N consecutive slots from k slot(s) before the slot in which the corresponding COT indicator is received. Alternatively, the COT indicator may be applied to N consecutive slots after k slot(s) from the slot in which the corresponding COT indicator is received. One or more of the slots to which the COT indicator is applied may not belong to the COT secured by the base station. When the index included in the COT indicator indicates the structure information of the slot(s), the base station may inform the terminal of the number (M) of valid slots to which the COT indicator is applied. The number of valid slots (M) may be indicated in the form of an index. Here, it may be defined as "1≤M≤N".

In the embodiment shown in FIG. 9, the number of valid slots to which the COT indicator transmitted in slot #4 is applied may be two. In the embodiment shown in FIG. 10, the number of valid slots to which the COT indicator transmitted in slot #5 is applied may be one. In the embodiment shown in FIG. 11, the COT indicator transmitted in slot #5 may be applied to the slot(s) located after the COT. Therefore, among slots belonging to the COT, there may not be valid slots to which the COT indicator transmitted in slot #5 is applied. In the embodiment shown in FIG. 12, the number of valid slots to which the COT indicator transmitted in slot #5 is applied may be three.

COT frequency resource structure

The COT indicator may include an index of a frequency resource. The index of the frequency resource may be an index of an LBT subband or a carrier index. The index of the frequency resource can be expressed in the form of a bitmap. One bit of the bitmap may indicate whether the LBT subband or carrier corresponding to the corresponding bit is used for DL transmission. The base station can check whether the LBT subbands or carriers are used by performing the LBT operation, generate a bitmap indicating the available LBT subband(s) or the available carrier(s), and generate a bitmap. It can transmit the included COT indicator.

The terminal may receive the COT indicator from the base station, and may check the LBT subband(s) available for DL transmission or the available carrier(s) based on the bitmap included in the COT indicator. The terminal may perform a monitoring operation in the LBT partial band(s) indicated by the bitmap included in the COT indicator or the CORESET in the carrier(s). Accordingly, the UE may not perform a monitoring operation in the LBT partial band(s) that is not available for DL transmission or the CORESET in the carrier(s).

The base station may set aggregated carriers to the terminal. The width of the activated cell or the activated BWP may not be greater than the width of the LBT partial band. Alternatively, the width of the BWP activated in the carrier set in the terminal may not be smaller than the width of the LBT partial band. The base station may configure a single carrier to the terminal without carrier aggregation. If the width of the single carrier is not greater than the width of the LBT subband, the terminal may not perform a decoding operation according to the frequency structure indicated by the COT indicator.

How to set the bitmap included in the COT indicator

The base station may not be able to use all unlicensed bands. In this case, the base station may set some LBT partial band(s) to the terminal. In order to configure the frequency resource for the terminal, the index of the carrier and/or the index of the LBT subband may be used. The index of the carrier may indicate frequency resources belonging to the corresponding carrier, and the index of the LBT subband may indicate frequency resources belonging to the corresponding LBT subband.

The base station may transmit system information including frequency resource information (eg, COT indicator) to the terminal. The terminal can receive system information from the base station and can check the COT indicator included in the system information. That is, the terminal can check the frequency resource based on the bitmap included in the COT indicator.

The base station may set the COT indicator to the terminal using higher layer signaling. In this case, the base station may explicitly inform the terminal of the location of the carrier in the frequency domain. The location of the carrier may be a center frequency, a start location of a common PRB (eg, point A), and/or an absolute radio-frequency channel number (ARFCN). The base station can set the CORESET and the search space, and can inform the terminal of the DCI format used for transmission of the COT indicator using higher layer signaling.

The operation of the base station may be performed on consecutive frequency resources. Accordingly, the base station may inform the terminal of the reference frequency resource and/or the reference bandwidth. The frequency resource information may include the index of the lowest frequency band and the number of frequency bands. The base station may inform the terminal of a function according to a combination of the index of the lowest frequency band and the number of frequency bands. For example, the frequency resource information may be a start and length indicator value (SLIV).

Since the bandwidth of the base station is determined in advance, an index representing the entire unlicensed band may be defined. The range of the index may be determined based on the number of LBT subbands belonging to the entire unlicensed band.

The base station may inform the terminal of one index. The terminal may receive one index from the base station, and may check the frequency resources of the COT secured by the base station based on the one index. S may be a carrier index of the unlicensed band. S set to 0 may indicate a carrier having the lowest frequency resource(s). N may indicate the number of carriers supported by the base station (eg, the maximum number). N may be an integer of 1 or more. The maximum value of N may be a value obtained by dividing the entire width of the unlicensed band by 20 MHz. N may mean the size of the bitmap. The order of bits constituting the bitmap may be an ascending or descending order of a frequency band.

When the entire width of the unlicensed band is X MHz and the width of the LBT partial band or the width of the carrier is Y MHz, the maximum value of N may be Z (=X/Y). When defined as "1≤N≤Z-S", SNIV may be defined as in Equation 1 below.

Time resource structure of COT and method of setting BWP

The slot format may be different for each LBT subband or carrier. For example, symbol A may be used as a DL resource in LBT subband #1, and the same symbol A may be used as a UL resource in LBT subband #2. The LBT subband #1 may be contiguous with the LBT subband #2 in the frequency domain. Alternatively, the LBT subband #1 may be discontinuous with the LBT subband #2 in the frequency domain. This can mean full-duplex communication. Therefore, when the base station uses a plurality of RF chains, a plurality of LBT subbands may be set.

The base station may set the DL carrier, the DL BWP, the UL carrier, and the UL BWP to the terminal using higher layer signaling. In a communication system supporting the FDD scheme, a distance between the center frequency of the DL carrier and the center frequency of the UL carrier may be a duplex gap. In a communication system supporting the TDD scheme, the center frequency of the DL carrier may be the same as the center frequency of the UL carrier, and the center frequency of the DL BWP may be the same as the center frequency of the UL BWP. A pair of DL BWP and UL BWP having the same center frequency may be activated.

When a plurality of LBT subbands are used in the unlicensed band, the base station may activate DL BWP and UL BWP having different center frequencies. The base station can secure the COT by performing the LBT operation, and can transmit a COT indicator indicating the time resource structure of the secured COT to the terminal(s). LBT partial band #1 may be used as a DL carrier, and LBT partial band #2 may be used as a UL carrier.

How to set the channel access type (eg, the type of LBT operation) using the UL grant and the COT indicator

The UE may receive the UL grant on the PDCCH and may transmit a PUSCH based on the UL grant. The UL grant may include the index(s) of the LBT subband(s) to which the PUSCH is mapped and the index(s) of the PUSCH interlace(s) required in the activated UL BWP. In addition, the UL grant may include a type of LBT operation performed for transmission of a PUSCH. The channel connection type (eg, the type of LBT operation) can be classified into no LBT, C1 LBT, C2 LBT, and C4 LBT.

The base station may independently determine the LBT subband(s) in which the LBT operation can be performed, and may inform the terminal of a bitmap indicating the LBT subband(s) in which the LBT operation is possible. One bit included in the bitmap may indicate that one or more LBT subbands are allocated to the terminal.

In addition, the base station can independently allocate interlaces to the terminal. Here, the interlace may be a PUSCH interlace. For example, the base station may inform the terminal of the bitmap or index indicating the interlace(s). One bit included in the bitmap may indicate that one or more interlaces are allocated to the terminal. The interlace(s) allocated to the terminal may be indicated by a combination of indices. The combination of indices may be a combination of a start index of an interlace and an index indicating the number of consecutive interlaces.

The interlace (eg, PUSCH interlace) may be indicated differently according to the subcarrier interval of the activated BWP. For example, when the subcarrier interval of the BWP is 30 kHz, the interlace may be indicated by a bitmap. When the subcarrier interval of the BWP is 15 kHz, the interlace may be indicated by an index. One index may indicate a combination of one or more interlaces. The interlace indication method may be determined in consideration of DCI overhead. When the number of interlaces is small, frequency resources may be allocated by a bitmap indicating interlaces. Since the size of the bitmap increases with the number of interlaces, when the number of interlaces is large, frequency resources may be allocated by an index indicating the interlace. In this case, the degree of freedom may be reduced, but the overhead of DCI may be reduced.

The UL grant may include a type of LBT operation performed for transmission of a PUSCH. However, the C4 LBT operation may not be performed in the LBT partial band secured by the base station. When the UL grant indicates no LBT, C1 LBT, or C2 LBT, the UE may perform the LBT operation indicated by the UL grant in the LBT subband(s) indicated by the UL grant, and perform the PUSCH LBT operation It can map to resources secured by.

When the UL grant indicates C4 LBT and one or more LBT subbands among the LBT subbands allocated to the UE are already secured by the base station, the UE is the remaining LBT part excluding one or more LBT subbands among the entire LBT subbands. Can perform C4 LBT operation in bands. The UE may determine the type of LBT operation performed in the LBT subband(s) to which the PUSCH is to be mapped using information other than the UL grant (eg, a COT indicator).

On the other hand, the terminal may transmit the PUSCH according to the configuration grant (configured grant). In this case, the terminal may not perform the C4 LBT operation in a specific LBT subband. For example, the terminal can check the LBT subband(s) secured by the base station based on the COT indicator, and no LBT operation, C1 LBT operation, or C2 LBT in the LBT subband(s) secured by the base station Dojok can be performed.

When the UE transmits the PUSCH in a single LBT subband according to the configuration grant, a no LBT operation, a C1 LBT operation, or a C2 LBT operation may be performed in a single LBT subband. When the UE transmits a PUSCH in a plurality of LBT subbands according to a configuration grant, a no LBT operation, a C1 LBT operation, or a C2 LBT operation may be performed in one or more LBT subbands among the plurality of LBT subbands, and , C4 LBT operation may be performed in the remaining LBT partial band(s).

Broadband BWP Within LBT Channel access method for each partial band

The UL grant can be used to schedule PUSCH transmission. The UL grant may be transmitted to the terminal through PDCCH (eg, DCI), higher layer signaling, or “a combination of PDCCH and higher layer signaling”. The base station can activate the wide UL BWP. In this case, the base station may transmit a UL grant including resource information of a PUSCH allocated to a plurality of LBT subbands within an activated wide UL BWP to the terminal.

The frequency resource(s) of the PUSCH indicated by the UL grant may be LBT partial band(s) that are not secured according to the LBT operation performed by the base station. The base station may transmit a UL grant indicating a channel access type (eg, a type of LBT operation) to the terminal. UL grant may indicate C4 LBT. The terminal can receive the UL grant from the base station, and can secure the LBT partial band(s) by performing an LBT operation (eg, C4 LBT operation) based on information included in the UL grant, and secured LBT PUSCH can be transmitted in partial band(s).

In the proposed method, the frequency resource(s) of the PUSCH indicated by the UL grant may be the LBT subband(s) secured by the LBT operation performed by the base station. The base station may transmit a UL grant indicating a channel access procedure (eg, C2 LBT) to the terminal. The terminal can receive the UL grant from the base station, and can secure the LBT partial band(s) by performing an LBT operation (e.g., C2 LBT operation) based on information included in the UL grant, and secured LBT PUSCH can be transmitted in partial band(s).

Meanwhile, the frequency resource(s) of the PUSCH indicated by the UL grant are the LBT subband(s) secured by the LBT operation performed by the base station and the LBT subband not secured by the LBT operation performed by the base station ( S) may be included. For example, PUSCH information #1 included in the UL grant may indicate the LBT partial band(s) secured by the LBT operation performed by the base station. PUSCH information #2 included in the UL grant may indicate the LBT subband(s) not secured by the LBT operation performed by the base station.

In consideration of the use efficiency of frequency resources, an operation of allocating a PUSCH in an LBT subband not secured by an LBT operation may be more advantageous than an operation of allocating a PUSCH in an LBT subband secured by an LBT operation. The UE may transmit the PUSCH by performing an LBT operation in one or more LBT subband(s) secured by the base station among LBT subbands indicated by the UL grant.

In the proposed method, one UL grant may indicate a plurality of channel access types (eg, C2 LBT and C4 LBT). The channel access type may be different for each LBT subband. One UL grant may indicate a channel access type applied to each of the LBT subbands. Since one UL grant indicates a plurality of channel access types, the size of one UL grant may increase. Accordingly, the DCI size or the higher layer signaling size may increase. The size of the UL grant may be changed according to the size of the UL BWP activated in the terminal.

In the proposed method, in order to maintain the size of the UL grant, one UL grant may indicate one channel access type (eg, a type of LBT operation). The UL grant may indicate no LBT, C1 LBT, or C2 LBT. In this case, the UE may perform a no LBT operation, a C1 LBT operation, or a C2 LBT operation indicated by the UL grant in all LBT subbands to which the PUSCH indicated by the UL grant belongs. The UE may determine that all LBT subbands to which the PUSCH indicated by the UL grant belongs is secured by the LBT operation performed by the base station. Even in this case, the UL grant may indicate C4 LBT. Accordingly, the terminal may perform the C4 LBT operation indicated by the UL grant even in the LBT partial band(s) secured by the LBT operation performed by the base station. Alternatively, one or more LBT subband(s) capable of performing a no LBT operation, a C1 LBT operation, or a C2 LBT operation among the LBT subband(s) secured by the LBT operation performed by the base station are based on the COT indicator. Can be confirmed. The terminal may perform a no LBT operation, a C1 LBT operation, or a C2 LBT operation in one or more LBT subband(s) identified by the COT indicator.

In the proposed method, when the UL grant indicates C4 LBT, the UE may perform the C4 LBT operation in all LBT subbands to which the PUSCH indicated by the UL grant belongs. The terminal can check the LBT partial band(s) secured by the LBT operation performed by the base station based on the COT indicator, and can perform the C4 LBT operation in the LBT partial band(s) identified by the COT indicator. . According to this method, the time during which the LBT operation is performed in the LBT partial band secured by the base station may be shorter than the time defined in the 3GPP technical standard (eg, 0 µs, 16 µs, or 25 µs). Accordingly, the terminal may determine that another terminal or base station is already performing transmission. Since the delay time according to the C4 LBT is larger than the preset time, the LBT operation may fail in the LBT partial band where the C4 LBT operation is performed.

In the proposed method, the UE may perform a no LBT operation, a C1 LBT operation, or a C2 LBT operation in one or more subband(s) indicated by the COT indicator among LBT subbands indicated by the UL grant. The UE may perform a C4 LBT operation in the remaining subband(s) excluding one or more subband(s) indicated by the COT indicator among the LBT subbands indicated by the UL grant. That is, the type of the LBT operation performed by the terminal may be determined by the COT indicator as well as the UL grant. According to this method, the execution time of the LBT operation of the terminal in the LBT subband secured by the base station may be shorter than the time defined in the 3GPP technical standard (eg, 0 µs, 16 µs, or 25 µs). Accordingly, the terminal may determine that another terminal or base station is already performing transmission. In this case, when the terminal performs the C4 LBT operation, the LBT operation may fail in the corresponding LBT subband. When the terminal performs a no LBT operation, a C1 LBT operation, or a C2 LBT operation, the LBT operation may be successful in the corresponding LBT subband.

13 is a conceptual diagram showing a first embodiment of a method of performing an LBT operation in a communication system.

Referring to FIG. 13, a UE may receive a UL grant from a base station through DCI, higher layer signaling, or “a combination of DCI and higher layer signaling”. The UL grant may indicate that the C4 LBT operation is performed in the LBT partial band #1-2. In addition, the terminal may receive a COT indicator for the LBT subband #1-2 from the base station. The COT indicator may indicate the channel access state of the base station in the LBT subband #1-2. For example, the COT indicator may indicate that the LBT subband #1 is not secured by the LBT operation performed by the base station and that the LBT subband #2 is secured by the LBT operation performed by the base station.

The terminal may determine the type of LBT operation based on the UL grant and the COT indicator. For example, the terminal may perform a C4 LBT operation in LBT subband #1, and may perform a no LBT operation, C1 LBT operation, or C2 LBT operation in LBT subband #2. The start time of the LBT operation in LBT subband #1 may be different from the start time of the LBT operation in LBT subband #2.

If the LBT operation fails in one or more LBT subbands among the LBT subbands to which the PUSCH allocated by the base station belongs, the UE may not transmit the PUSCH in one or more LBT subbands in which the LBT operation has failed. Accordingly, the UE can transmit the PUSCH in the LBT subband(s) in which the LBT operation is successful among the LBT subbands. Alternatively, if the LBT subband(s) in which the LBT operation has failed exists, the UE may not transmit the PUSCH in all LBT subbands.

PUSCH transmission method at the time shared by the base station

The base station may transmit a UL grant for scheduling a PUSCH to the terminal through a DCI, an RRC message, or a "combination of a DCI and RRC message". The time resource information of the PUSCH included in the UL grant may indicate a plurality of slots (hereinafter, referred to as "PUSCH occasion"). The PUSCH occasion may include a plurality of PUSCH instances. One PUSCH instance may be a time interval in which one PUSCH is transmitted. The mapping type between the PUSCH and the PUSCH instance may be classified into a mapping type A (eg, PUSCH mapping type A) and a mapping type B (eg, PUSCH mapping type B). In mapping type A, the PUSCH instance may be a time interval set in units of slots. In mapping type B, the PUSCH instance may be a time interval set in a mini-slot unit. The number of symbols included in the slot may be greater than the number of symbols included in the mini-slot. As the number of PUSCH instances increases, the number of times the C4 LBT operation is performed may increase.

The PUSCH instance may correspond to one HARQ process. Therefore, one PUSCH occasion is preferably composed of a plurality of PUSCH instances. For example, the first slot of the PUSCH occasion may be configured based on the mapping type B. Therefore, the first slot of the PUSCH occasion may include a plurality of PUSCH instances. Among the slots constituting the PUSCH occasion, the remaining slot(s) except for the first slot may be set based on the mapping type A.

The base station may set one LBT subband to the terminal. The terminal may perform the LBT operation in the LBT subband set by the base station, and may transmit the PUSCH in the LBT subband when the LBT operation is successful. The terminal may check the channel access type indicated by the UL grant (eg, no LBT, C1 LBT, C2 LBT, or C4 LBT). The base station may transmit configuration information for reception of the COT indicator to the terminal using higher layer signaling. In this case, the terminal may check the start position and end position of the time interval (eg, COT) secured by the base station.

The PUSCH occasion may overlap with a time period secured by the base station. In this case, the terminal may not know whether it is allowed to change the type of LBT operation based on the COT indicator. If the change in the type of the LBT operation is not allowed, the terminal may perform an LBT operation (e.g., no LBT operation, C1 LBT operation, C2 LBT operation, or C4 LBT operation) indicated by the UL grant. If the change of the type of LBT operation is allowed, the terminal performs a no LBT operation, a C1 LBT operation, or a C2 LBT operation (e.g., an LBT operation indicated by the COT indicator) even when the UL grant indicates C4 LBT. can do.

In order to apply the above-described method, various cases can be considered. In the first case, all PUSCH instances included in the PUSCH occasion may belong to a time interval secured by the LBT operation performed by the base station. In this case, the UE may determine (or change) the type of LBT operation performed in the PUSCH occasion in consideration of both the UL grant and the COT indicator.

In the second case, some of the PUSCH instances included in the PUSCH occasion may belong to a time interval secured by the LBT operation performed by the base station. In particular, only some symbol(s) included in the PUSCH instance may belong to a time interval secured by the base station. The type of LBT operation performed in some PUSCH instance(s) (e.g., some symbol(s) included in the PUSCH instance) belonging to the time interval secured by the base station is determined in consideration of both the UL grant and the COT indicator ( Or, it can be changed). The PUSCH instance partially overlapping with the time interval secured by the base station may include symbol(s) belonging to the time interval secured by the base station and symbol(s) that do not belong to the time interval secured by the base station.

In the proposed method, if one or more PUSCH instances belonging to the PUSCH occasion do not belong to the time interval secured by the base station, the UE is the category of LBT operation in all PUSCH instances belonging to the PUSCH occasion (e.g., channel access Type) can not be changed. When all PUSCH instances belonging to the PUSCH occasion belong to a time interval secured by the base station, the terminal may change the category of the LBT operation. The PUSCH occasion may be regarded as one resource, and the transmission opportunity of the UE may be set on a PUSCH occasion unit. Alternatively, the PUSCH instance may be regarded as one resource, and the transmission opportunity of the terminal may be set on a PUSCH instance basis. When the PUSCH instance is regarded as one resource, the transmission opportunity of the terminal may be greater than the transmission opportunity of the terminal when the PUSCH occasion is considered as one resource.

In the proposed method, the UE may not transmit a PUSCH in a PUSCH instance including a symbol that does not belong to a time interval secured by the base station. That is, the UE may transmit the PUSCH from the PUSCH instance(s) belonging to the time interval secured by the base station among the PUSCH instances included in the PUSCH occasion. The base station may regard all symbols included in the PUSCH instance as symbols allocated by the base station. Alternatively, the base station may consider that the PUSCH is not transmitted in a specific PUSCH instance.

In the proposed method, the UE may transmit the PUSCH in symbol(s) belonging to a time interval secured by the base station among all symbols included in the PUSCH instance. For PUSCH transmission, a rate matching operation or puncturing operation in units of symbols may be performed in the PUSCH instance. PUSCH instances configured in the terminal may be PUSCH instances according to mapping type A or PUSCH instances according to mapping type B. When the rate matching operation is performed, the terminal may check the number of mappable symbols based on the UL grant and the COT indicator, determine the size of the resource based on the number of mappable symbols, and based on the size of the resource. The size of a transport block (TB) can be determined.

In the proposed method, the UE performs a rate matching operation or puncturing operation in units of symbols without distinction between DM-RS and data (eg, configured grant (CG)-UCI, UCI, and UL-SCH (shared channel)). can do. That is, the terminal can transmit the PUSCH in a time interval secured by the base station without separate operation. The UE may determine that some symbol(s) are available among all symbols included in the PUSCH instance, and may transmit the PUSCH in the corresponding PUSCH instance. "When the number of unusable symbols in a PUSCH instance is greater than the number of usable symbols" or "When the number of PUSCH instances having symbol(s) unavailable in a PUSCH occasion is greater than the number of PUSCH instances having only usable symbols ", the UE may not transmit the corresponding PUSCH instance(s) (eg, PUSCH instance(s) having unusable symbol(s)).

In the proposed method, the terminal that has transmitted the DM-RS can expect that the number of symbols to which data is to be transmitted is greater than the number of preset symbols. If the number of symbols to which data is to be transmitted is not greater than the number of symbols set in advance, the UE may not transmit the PUSCH in the corresponding PUSCH instance. Here, the number of preset symbols may be defined in the 3GPP technical standard. Alternatively, the number of preset symbols may be set by higher layer signaling.

When the number of usable symbols is less than the number of preset symbols, the terminal may not use the symbol(s) belonging to the time interval secured by the base station. Therefore, the UE may not transmit DM-RM and data in the corresponding PUSCH instance. The reason is that even when the base station performs a reception operation in the corresponding PUSCH instance, it cannot successfully decode data. Since the UE does not transmit the PUSCH in the PUSCH instance, interference may be reduced in a communication system. The terminal may perform a C4 LBT operation to transmit a PUSCH in a PUSCH instance belonging to a time interval that is not secured by the base station. When one or more symbols included in the PUSCH instance do not belong to the time interval secured by the base station, the terminal may perform a C4 LBT operation on one or more symbols.

In the third case, all PUSCH instances belonging to the PUSCH occasion may completely belong to the time interval secured by the LBT operation performed by the base station. Alternatively, all PUSCH instances belonging to the PUSCH occasion may not belong to the time interval secured by the LBT operation performed by the base station. In this case, the UE can transmit the PUSCH in the PUSCH instance(s) belonging to the time interval secured by the base station, and can perform the C4 LBT operation in the PUSCH instance(s) not belonging to the time interval secured by the base station. .

The time during which the C4 LBT operation is performed may be subdivided. The base station may inform the terminal of the subdivided time for the C4 LBT operation. A PUSCH instance that completely belongs to a time interval secured by the base station may be referred to as a PUSCH instance #n, and a PUSCH instance that does not belong to a time interval secured by the base station may be referred to as a PUSCH instance #n+1. PUSCH instance #n+1 may be contiguous with PUSCH instance #n in the time domain. Alternatively, PUSCH instance #n+1 may be discontinuous with PUSCH instance #n in the time domain.

In the proposed method, the UE may perform a C4 LBT operation in the last symbol of PUSCH instance #n. The UE may not transmit the last sample among samples constituting the last symbol of PUSCH instance #n. That is, the terminal can perform the C4 LBT operation in the last sample. Alternatively, the UE may not perform a transmission operation in the last symbol of PUSCH instance #n. In this case, the UE may determine that the number of symbols usable in PUSCH instance #n is less than the number of symbols usable in other PUSCH instances. Therefore, the UE may not transmit data in the last symbol by performing a puncturing operation or a rate matching operation on the last symbol of PUSCH instance #n.

Alternatively, the terminal may map the same data as the data mapped to the symbol before the last symbol of the PUSCH instance #n to the last symbol. The same data can be mapped to two consecutive symbols. That is, data mapped to a symbol before the last symbol may be cyclically extended to the last symbol. In this case, the UE may determine that the number of symbols usable in PUSCH instance #n is less than the number of symbols usable in other PUSCH instances. Accordingly, the UE may perform a puncturing operation or a rate matching operation for PUSCH instance #n.

In the proposed method, the UE may perform a C4 LBT operation in the start symbol of PUSCH instance #n+1. The UE may not transmit the first sample among samples constituting the start symbol of PUSCH instance #n+1. That is, the terminal can perform the C4 LBT operation in the first sample. In the proposed method, data mapped to the start symbol of PUSCH instance #n+1 may be transmitted.

Alternatively, data identical to data mapped to the second symbol of PUSCH instance #n+1 may be mapped to the start symbol (ie, the first symbol) of PUSCH instance #n+1. The same data can be mapped to two consecutive symbols. That is, data mapped to the second symbol may be cyclically extended to the first symbol. Data identical to the data mapped to the second symbol may be mapped to samples of the first symbol. In this case, the UE may determine that the number of symbols usable in PUSCH instance #n+1 is less than the number of symbols usable in other PUSCH instances. Accordingly, the UE may perform a puncturing operation or rate matching operation for PUSCH instance #n+1.

14 is a conceptual diagram showing a second embodiment of a method of performing an LBT operation in a communication system.

Referring to FIG. 14, a PRACH occasion may include a plurality of PUSCH instances. Among the plurality of PUSCH instances included in the PRACH occasion, one or more PUSCH instances may belong to a time interval (e.g., COT) secured by the base station, and the remaining PUSCH instance(s) are a time interval secured by the base station. May not belong to The terminal may perform a no LBT operation, a C1 LBT operation, or a C2 LBT operation in the PUSCH instance(s) belonging to the time interval secured by the base station. The terminal may perform a C4 LBT operation in a PUSCH instance that does not belong to the time secured by the base station.

The LBT operation for PUSCH instance #n may be performed in the last symbol of PUSCH instance #n-1 located before PUSCH instance #n. Accordingly, the C4 LBT operation may be performed in the last symbol of the last PUSCH instance belonging to the time interval secured by the base station. That is, the terminal may transmit the PUSCH by performing a puncturing operation or a rate matching operation on the last PUSCH instance belonging to the time interval secured by the base station.

15 is a conceptual diagram showing a third embodiment of a method of performing an LBT operation in a communication system.

Referring to FIG. 15, a PRACH occasion may include a plurality of PUSCH instances. Among the plurality of PUSCH instances included in the PRACH occasion, one or more PUSCH instances may belong to a time interval (e.g., COT) secured by the base station, and the remaining PUSCH instance(s) are a time interval secured by the base station. May not belong to The terminal may perform a no LBT operation, a C1 LBT operation, or a C2 LBT operation for PUSCH instance(s) belonging to a time interval secured by the base station. The terminal may perform a C4 LBT operation for a PUSCH instance that does not belong to the time secured by the base station.

The LBT operation for PUSCH instance #n may be performed in the first symbol of PUSCH instance #n. Accordingly, the terminal may perform the C4 LBT operation in the first symbol of the PUSCH instance that does not belong to the time interval secured by the base station. That is, the UE may transmit the PUSCH by performing a puncturing operation or a rate matching operation on a PUSCH instance that does not belong to a time interval secured by the base station.

Transmission method of a UL grant indicating a plurality of carriers (eg, a carrier in a licensed band and a carrier in an unlicensed band)

The terminal can operate in both a licensed band and an unlicensed band. The DL carrier of the licensed band may be referred to as a "DL licensed carrier", and the UL carrier of the licensed band may be referred to as a "UL licensed carrier". Carriers in the unlicensed band may be referred to as “unlicensed carriers”. When the DL licensed carrier is aggregated with the unlicensed carrier, the DL licensed carrier may be activated as a carrier of a PCell or a carrier of an SCell. When the UL licensed carrier is aggregated with the unlicensed carrier, the UL licensed carrier may be activated as a carrier for PUCCH transmission. The base station may transmit a UL grant including scheduling information of a PUSCH located on a UL licensed carrier and an unlicensed carrier to the UE. The UL grant may be transmitted through DCI.

The base station may transmit a UL grant including information explicitly indicating a carrier used for PUSCH transmission to the terminal. A carrier indicator field (CIF) included in the UL grant may indicate a carrier used for PUSCH transmission. The UL grant for scheduling PUSCH transmission in the unlicensed band may include a type of LBT operation (eg, a C2 LBT operation or a C4 LBT operation), a PUSCH interlace, and/or a trigger type. The trigger type may indicate whether the terminal receives a separate trigger signal from the base station. The UL grant for scheduling PUSCH transmission in the licensed band may not include the above-described information. In the licensed band, the PUSCH may be located in consecutive PRBs or discontinuous PRBs. The time resource allocation method of the PUSCH in the licensed band may be different from the time resource allocation method of the PUSCH in the unlicensed band.

In the proposed method, a plurality of DCI formats for UL grant may be configured in the terminal. The first DCI format may mean a UL grant for PUSCH transmission in a licensed band, and the second DCI format may mean a UL grant for PUSCH transmission in an unlicensed band. The first DCI format and the second DCI format may be mapped to the same CORESET and the same search space. The size of the first DCI format may be different from the size of the second DCI format. The third DCI format may be a UL grant that schedules transmission of a plurality of PUSCHs.

The first DCI format may be classified into a 1-1 DCI format and a 1-2 DCI format. The 1-1th DCI format may be used for a fallback operation. The 1-2 DCI format may be used for operations other than a fallback operation. In addition, the second DCI format may be classified into a 2-1 DCI format and a 2-2 DCI format, and the third DCI format may be classified into a 3-1 DCI format and a 3-2 DCI format. The 2-1 DCI format and the 3-1 DCI format may be used for a fallback operation. The 2-2 DCI format and the 3-2 DCI format may be used for different operations.

In the proposed method, the type of DCI (eg, DCI format) for each of the CORESETs (eg, search spaces) can be distinguished. Accordingly, the terminal can expect to receive one type of UL grant in one CORESET (eg, one search space). That is, the terminal may expect to receive resource allocation information of the PUSCH of the unlicensed band or the resource allocation information of the PUSCH of the licensed band in one CORESET (eg, one search space).

The DCI format used for scheduling PUSCH transmission in the licensed band may be a "first DCI format" or a "1-1 DCI format and a 1-2 DCI format". The DCI format used for scheduling PUSCH transmission in the unlicensed band is "2nd DCI format", "2-1 DCI format and 2-2 DCI format", "2-1 DCI format, 2-2 DCI. Format, and 3-2 DCI format", or "2-1 DCI format, 2-2 DCI format, 3-1 DCI format, and 3-2 DCI format".

PUSCH transmission power information may be included in the UL grant. Alternatively, the transmission power information of the PUSCH may be transmitted through a separate DCI (eg, DCI having a specific format). A separate DCI may be used to indicate the transmission power of the PUSCH or SRS.

Priority in terms of transmit power in simultaneous transmission procedure

The UE can transmit the PUSCH in the unlicensed band and the PUCCH in the licensed band. In this case, the terminal may receive the DCI including the UL grant. In addition, the UE may receive a DCI including DL allocation information, may receive DL data through a PDSCH indicated by the DL allocation information, and transmit a HARQ response for DL data through a PUCCH.

In the proposed method, the transmission power of the terminal may be determined based on a late received DCI among UL-DCI including UL grant and DL-DCI including DL allocation information. For example, the UE may first receive the UL-DCI including the UL grant and the TPC of the PUSCH, and then may receive the DL-DCI including the DL allocation information and the TPC of the PUCCH. When power for simultaneous transmission of PUSCH and PUCCH is insufficient, the UE can use sufficient transmission power for PUCCH transmission based on the TPC included in the DL-DCI received after UL-DCI, and the remaining transmission power is used for PUSCH transmission. Can be used for

Alternatively, the UE may first receive the DL-DCI including the DL allocation information and the TPC of the PUCCH, and then may receive the UL-DCI including the UL grant and the TPC of the PUSCH. When power for simultaneous transmission of PUSCH and PUCCH is insufficient, the UE can use sufficient transmission power for PUSCH transmission based on the TPC included in the UL-DCI received after the DL-DCI, and transmit the remaining transmission power for PUCCH. Can be used for

In the proposed method, the terminal may select one channel from among a plurality of channels according to a preset priority, and may determine transmission power for one channel. The UE may select the PUSCH or PUCCH according to the priority according to the 3GPP technical standard or higher layer signaling instead of the DL-DCI and UL-DCI reception order. The UE may first use sufficient transmission power for transmission of the selected channel (eg, PUSCH or PUCCH). The priority of the PUCCH for transmission of UCI including the HARQ response may be different from the priority of the PUCCH for transmission of UCI including CSI.

For example, the priority of the UL grant may be higher than that of CSI (eg, periodic CSI reporting). The priority of the UL grant may be lower than the priority of the HARQ response. The UE may use sufficient transmission power for transmission of a HARQ response or UCI (eg, PUCCH) including "HARQ response and CSI", and may use the remaining transmission power for PUSCH transmission. Alternatively, the UE may use sufficient transmit power for PUSCH transmission, and may use the remaining transmit power for UCI (eg, PUCCH) transmission including CSI.

Method for allocating frequency resources belonging to a plurality of LBT subbands in a transmission procedure of PDSCH/PUSCH/PUCCH/SRS in an unlicensed band

The base station may succeed in LBT operation in a plurality of LBT subbands. In this case, the base station may transmit data to the terminal using a plurality of LBT subbands. When the UE operates in one LBT subband (for example, when UL BWP is activated within one LBT subband), the UE may receive a UL grant including an index of a PUSCH interlace from the base station. The index of the PUSCH interlace may be indicated by a specific bit of the bitmap included in the UL grant.

The UL BWP may be activated in a plurality of LBT subbands, and the UL grant may indicate the index of the PUSCH interlace. UEs as many as the number of PUSCH interlaces may be multiplexed in the frequency domain. The number of terminals multiplexed in the frequency domain may be small. In order to multiplex a large number of terminals in the frequency domain, a large amount of time may be required. The maximum time period occupied by the base station and/or the terminal in the unlicensed band may be determined according to frequency regulation.

It may be desirable to multiplex a plurality of terminals in the frequency domain in the same time interval. For example, a plurality of terminals associated with one PUSCH interlace may be multiplexed in the frequency domain. When the terminal transmits a small TB, the width of the required BWP may be small. Alternatively, a part of the PUSCH interlace (eg, part of frequency resources) within the BWP may be allocated to the terminal.

In the proposed method, when allocating frequency resources of the PUSCH, the base station may inform the terminal of the index indicating the LBT subband. In the procedure for determining the frequency resource of the PUSCH, the UE maps the encoded TB based on the BWP index, the index(s) of the PUSCH interlace(s), and the index(s) of the LBT subband(s) (e.g. For example, a start PRB index, an end PRB index, and the number of PRBs belonging to the PUSCH interlace) can be derived.

In the PUSCH transmission procedure, the UL grant may include information indicating UL BWP and an index of a PUSCH interlace. According to the subcarrier interval of the PUSCH, the index of the PUSCH interlace may be indicated by a "bit string" or an "index indicating a combination of a start position and a length". A PUSCH interlace belonging to the UL BWP may be selected, and one or more PRB(s) may be selected based on the index(s) of the LBT subband(s) among PRBs indicated by the index of the selected PUSCH interlace. The selected one or more PRB(s) may be set as PUSCH, and may belong to the LBT subband indicated by the index of the LBT subband.

A guard band may exist between adjacent LBT subbands. When different base stations or different terminals perform transmission in adjacent LBT subbands, interference may occur. In this case, it may be desirable to allocate a guard band having a sufficient size. In the proposed method, the location and size of the guard band can be defined for each LBT sub-band. The location and size of the guard band can be defined in the 3GPP technical standard. Alternatively, the base station may transmit information indicating the location and size of the guard band to the terminal.

For UEs with different LBT subbands to which frequency resources allocated by the UL grant (e.g., UL BWP, PUSCH interlace bit stream (or index), LBT subband bit stream (or index)) belong When adjacent to the LBT subband, the UE may map the encoded TB to PRB(s) belonging to the guard band for the LBT subband. For example, when transmission is allowed in contiguous LBT subbands, the UE may map the encoded TB to PRB(s) belonging to guard bands for adjacent LBT subbands.

The terminal may derive the index(s) of the PRB(s) belonging to the guard band based on the subcarrier interval and point A of the BWP. In the proposed method, when a plurality of UL transmissions occur at the same time, and one or more UL transmissions among the plurality of UL transmissions are PUSCH transmission(s), the terminal may map the encoded TB to the guard band between adjacent LBT subbands. I can.

When the PUSCHs indicated by the plurality of UL grants have the same time interval, the PUSCH may be multiplexed in the frequency domain. The first UL grant may include allocation information of PUSCH interlace(s) belonging to a specific LBT subband(s), and the second UL grant received after the first UL grant is specified by the first UL grant. It may include allocation information of the PUSCH interlace(s) belonging to the LBT subband(s) adjacent to the LBT subband. In this case, the UE may map the encoded TB to PRB(s) belonging to a guard band between adjacent LBT subbands. The PUSCH interlace allocated by the first UL grant may be the same as the PUSCH interlace allocated by the second UL grant. Alternatively, the PUSCH interlace allocated by the first UL grant may be different from the PUSCH interlace allocated by the second UL grant. The UE may map a TB allocated by one or more UL grants among the first UL grant and the second UL grant to PRB(s) belonging to the guard band.

The PUSCH scheduled by one UL grant may be transmitted in a first LBT subband, and a PUCCH (or SRS) may be transmitted in a second LBT subband adjacent to the first LBT subband. PUSCH and PUCCH (or SRS) may be transmitted in the same time interval. When the LBT subbands are adjacent, the UE may transmit the PUSCH in the first LBT subband, and the PUCCH (or SRS) may be transmitted in the second LBT subband adjacent to the first LBT subband. The PUCCH (or SRS) interlace may be the same as the PUSCH interlace. Alternatively, the PUCCH (or SRS) interlace may be different from the PUSCH interlace. Here, the interlace may be set in PRB units or RE units. In the proposed method, the UE may transmit PUSCH in PRB(s) belonging to a guard band between LBT subbands. The size of the TB mapped to the PUSCH may be determined according to the result of the rate matching operation (eg, the result of the operation of mapping the TB to PRB(s) belonging to the guard band).

PUCCH may be transmitted using frequency resources limited to one LBT subband. SRS may be transmitted in a plurality of LBT subbands. In the proposed method, the UE can multiplex the SRS with the PUSCH in the frequency domain. In this case, the UE may perform one UL transmission (eg, SRS transmission) in PRB(s) belonging to a guard band between LBT subbands. When the SRS interlace is set on a subcarrier basis, PUSCH and SRS may not be multiplexed in the frequency domain of the guard band. The UE may not adjust the size of the TB mapped to the PUSCH according to whether the SRS is transmitted. That is, the PRB(s) to which the TB is mapped may not include the PRB(s) belonging to the guard band.

When the PDSCH and/or PDCCH is not received, the UE may not be able to transmit the PUCCH according to discontinuous transmission (DTX). In this case, the UE may not know the existence of the PUCCH, and may not transmit both the PUCCH and the PUSCH in adjacent LBT subbands. Therefore, the UE may not be able to perform transmission in the PRB(s) belonging to the guard band between LBT subbands. The size of the TB mapped to the PUSCH may be determined according to the result of the rate matching operation. PRB(s) to which TB is mapped may not include PRB(s) belonging to the guard band.

The UE may transmit the SRS and PUCCH in the same time interval. The first LBT subband through which the SRS is transmitted may be adjacent to the second LBT subband through which the PUCCH is transmitted. In this case, the guard band between the LBT subbands may not be used. Alternatively, the terminal may transmit the SRS through the PRB(s) belonging to the guard band between the LBT subbands.

The SRS may be transmitted through a plurality of LBT subbands. One or more LBT subbands among a plurality of LBT subbands in which SRS is transmitted may be used for PUCCH transmission. The SRS may be transmitted in PRB(s) belonging to a guard band between LBT subbands. Alternatively, the UE may select one UL transmission from among a plurality of UL transmissions (eg, SRS or PUCCH), and the selected UL transmission may be performed in PRB(s) belonging to the guard band.

How to interpret fields included in DCI according to changes in BWP

The DCI may include resource allocation information of the PDSCH or resource allocation information of the PUSCH, and the BWP through which the PDSCH or PUSCH is transmitted by the corresponding DCI may be changed from BWP #1 to BWP #2. When the width of BWP #1 is different from the width of BWP #2, the sizes of fields indicating frequency resources in DCI may be different.

The BWP on which the terminal operates may be changed from BWP #1 to BWP #2, and the width of BWP #2 may be larger than the width of BWP #1. In this case, the UE may interpret a field indicating frequency resources of the PUSCH belonging to BWP #1, and bit(s) necessary to indicate the frequency resources of the PUSCH belonging to BWP #2 in the corresponding field (e.g., 0 or 1) can be added (prepend). The BWP on which the terminal operates may be changed from BWP #1 to BWP #2, and the width of BWP #1 may be larger than the width of BWP #2. In this case, the UE can interpret a field indicating frequency resources of the PUSCH belonging to BWP #1, and among bits of the field, unnecessary bit(s) to indicate the frequency resources of the PUSCH belonging to BWP #2 (e.g. For example, you can ignore the most significant bit (MSB). That is, the UE can check the frequency resources of the PUSCH belonging to BWP #2 by analyzing the least significant bit (LSB) of the field indicating the frequency resources of the PUSCH belonging to BWP #1.

The structure of the bit stream indicating frequency resources of the PUSCH in the unlicensed band may be different from the structure of the bit stream indicating frequency resources of the PUSCH in the licensed band. Information indicating frequency resources of the PUSCH in the unlicensed band may indicate the LBT subband and the PUSCH interlace. Frequency resources of the PUSCH in the licensed band can be interpreted from one bit stream.

In the proposed method, the UL grant may include a bit sequence indicating frequency resources of the PUSCH of the unlicensed band, and the corresponding bit sequence includes a first bit sequence indicating the LBT subband and a second bit sequence indicating the PUSCH interlace. Can include. Bit(s) (eg, 0 or 1) may be added to each of the first bit stream and the second bit stream. The bit(s) added to each of the first bit stream and the second bit stream may be MSBs. Alternatively, the LSB may be used among the first bit string and the second bit string. The bit stream may mean a bitmap, and one bit of the bit stream may indicate one LBT subband or one PUSCH interlace. Alternatively, the entire bit stream may be the index(s) of the LBT subband(s) or the index(s) of the PUSCH interlace(s).

BWP #1 may be included in one LBT subband (eg, an LBT subband having a size of 20MHz). In this case, the UL grant may not include a bit stream indicating the LBT subband to which the PUSCH is allocated. The frequency resources of the PUSCH can be indicated only by the bit stream of the PUSCH interlace.

When BWP #2 is included in one LBT subband, frequency resources of the PUSCH may be indicated by a bit sequence of the PUSCH interlace. Here, the length of the bit string of the PUSCH interlace may vary. When the subcarrier interval Δf ₁ of BWP # ₁ is greater than the subcarrier interval Δf _{2 of} BWP #2, the number of PUSCH interlaces in BWP #2 may be less than the number of PUSCH interlaces in BWP #1. Accordingly, the UE can omit some bit(s) from the bit string of the PUSCH interlace in BWP #1, and can check the frequency resources of the PUSCH in BWP #2 by analyzing the omitted bit string.

For example, when Δf ₁ is 15 kHz, the bit string of the PUSCH interlace may be composed of 10 bits or 6 bits. When Δf ₂ is 30 kHz, the bit string of the PUSCH interlace may consist of 5 bits. The UE can ignore 5 MSBs in a bit string having a size of 10 bits, and can check the frequency resources of the PUSCH in BWP #2 by analyzing the remaining 5 LSBs. Alternatively, the UE may ignore 1 MSB in a bit stream having a size of 6 bits, and may check the frequency resources of the PUSCH in BWP #2 by analyzing the remaining 5 LSBs.

When Δf ₂ is greater than Δf ₁ , the UE may generate an extended bit stream by adding a preset bit(s) (eg, 0 or 1) to the bit stream of the PUSCH interlace in BWP #1. By analyzing the bit stream, frequency resources of the PUSCH can be checked in BWP #2. For example, when Δf ₁ is 15 kHz, the bit string of the PUSCH interlace may consist of 5 bits. When Δf ₂ is 30 kHz, the bit stream of the PUSCH interlace may be composed of 10 bits or 6 bits.

The UE can generate an extended bit string by adding 5 bits to a bit string having a size of 5 bits, and can check the frequency resources of the PUSCH in BWP #2 by analyzing the extended bit string having a size of 10 bits. . Alternatively, the UE can generate an extended bit stream by adding 1 bit to a bit stream having a size of 5 bits, and check the frequency resources of the PUSCH in BWP #2 by analyzing the extended bit stream having a size of 6 bits. I can.

Meanwhile, BWP #2 may be included in a plurality of LBT subbands. The bit stream indicating frequency resources of the PUSCH of BWP #1 may not include the bit stream of the LBT subband. In order to indicate the frequency resources of the PUSCH in BWP #2, the bit string for BWP #1 may include a bit string of the LBT subband. In the proposed method, the UE can interpret some of the bit strings indicating the frequency resources of the PUSCH in BWP #1 as a bit string of the LBT subband, and can interpret the remaining bit strings as a bit string of the PUSCH interlace. have. Here, the bit sequence of the LBT subband may be a bitmap, the number of bits included in the bitmap may be the same as the number of LBT subbands in BWP #2, and the remaining bit streams indicate PUSCH interlaces of BWP #2. Can be used to The remaining bit streams may not indicate all combinations of PUSCH interlaces of BWP #2. The UE may generate an extended bit stream by adding bit(s) (eg, 0 or 1) to a bit stream indicating PUSCH interlaces of BWP #2.

The above-described method can be applied even when the number of LBT subbands included in BWP #2 is greater than the number of LBT subbands included in BWP #1. Among the entire bit strings indicating the frequency resources of the PUSCH in BWP #1, some bit strings may be used first to indicate the LBT subbands of BWP #2, and the remaining bit strings are used as a bit string of the PUSCH interlace of BWP #2. I can. The remaining bit streams may not indicate all combinations of PUSCH interlaces of BWP #2. The UE may generate an extended bit stream by adding bit(s) (eg, 0 or 1) to a bit stream indicating PUSCH interlaces of BWP #2.

DCI How to resize

The base station may perform a resource allocation operation for a licensed band and a resource allocation operation for an unlicensed band using a carrier aggregation (eg, frequency aggregation) method. The carrier through which the DCI including the resource allocation information of the data channel is transmitted may be the same as the carrier through which the data channel scheduled by the corresponding DCI is transmitted. This operation may be referred to as a "self scheduling scheme". Alternatively, a carrier through which a DCI including resource allocation information of a data channel is transmitted may be different from a carrier through which a data channel scheduled by a corresponding DCI is transmitted. This operation may be referred to as "cross carrier scheduling scheme".

When the cross-carrier scheduling scheme is used, a carrier through which resource allocation information for a licensed band is transmitted may be the same as a carrier through which resource allocation information for an unlicensed band is transmitted. The DCI may further include a field indicating whether the resource allocation information included in the DCI is resource allocation information for a licensed band or resource allocation information for an unlicensed band. The terminal can receive the DCI from the base station in the corresponding carrier, and can check whether the resource allocation information included in the DCI is resource allocation information for the licensed band or the resource allocation information for the unlicensed band based on a field included in the DCI. .

In the proposed method, a carrier indication field (CIF) included in the DCI may indicate whether the resource allocation information included in the DCI is resource allocation information for a licensed band or resource allocation information for an unlicensed band. . The UE may check whether the resource allocation information included in the DCI is resource allocation information for a licensed band or resource allocation information for an unlicensed band based on the CIF included in the DCI.

The size of resource allocation information for a carrier in the licensed band may be different from the size of resource allocation information for a carrier in the unlicensed band. For example, the size of the DCI including resource allocation information for the carrier of the licensed band may be different from the size of the DCI including resource allocation information for the carrier of the unlicensed band. In order to equalize the size of the DCIs, a preset bit(s) (eg, 0 or 1) may be added to a DCI having a small size among DCIs.

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 control information including first information indicating one or more physical uplink shared channel (PUSCH) interlaces set in the unlicensed band from the base station;
Checking frequency resources corresponding to the one or more PUSCH interlaces; And
And transmitting a PUSCH to the base station using the frequency resources of the unlicensed band. The method according to claim 1,
The first information is a bitmap, and each of the bits included in the bitmap indicates a PUSCH interlace allocated for the terminal. The method according to claim 1,
The first information is an index, and the index indicates a combination of the one or more PUSCH interlaces allocated for the terminal. The method of claim 3,
The index includes information indicating a start PUSCH interlace among the one or more PUSCH interlaces and information indicating the number of the one or more PUSCH interlaces. The method according to claim 1,
The method of indicating the one or more PUSCH interlaces is different according to a subcarrier spacing of a bandwidth part (BWP) to which the one or more PUSCH interlaces belong. The method according to claim 1,
The control information further includes second information indicating one or more resource block (RB) sets set by the base station, and each of the one or more RB sets includes one or more RBs. The method of claim 6,
The one or more RB sets are frequency resources indicated by the base station. The method of claim 6,
The second information is a bitmap, and each of the bits included in the bitmap indicates a set of RBs allocated for the terminal. The method of claim 6,
When a plurality of RB sets are configured by the base station, a guard band is located between the plurality of RB sets, and the PUSCH is mapped to one or more RBs belonging to the plurality of RB sets. The method of claim 6,
The PUSCH is transmitted in the one or more PUSCH instances belonging to the one or more RB sets and the one or more PUSCH instances belonging to RBs other than the one or more RB sets, and the PUSCH in the one or more RB sets. The type of a listen before talk (LBT) operation performed for transmission is different from the type of the LBT operation performed for transmission of the PUSCH in RBs other than the one or more RB sets. The method according to claim 1,
The PUSCH is transmitted in a time interval other than the COT and the COT set by the base station, and the type of LBT operation performed for transmission of the PUSCH in the COT is performed for transmission of the PUSCH in a time interval other than the COT Different from the type of the LBT operation, the operation method of the terminal. The method according to claim 1,
The time interval in which the PUSCH can be transmitted includes a plurality of PUSCH instances, and when one or more PUSCH instances among the plurality of PUSCH instances do not belong to the COT set by the base station, the PUSCH is in the time interval. Not transmitted, the operating method of the terminal. The method according to claim 1,
The time period in which the PUSCH can be transmitted includes a plurality of PUSCH instances, and when one or more PUSCH instances among the plurality of PUSCH instances do not belong to the COT set by the base station, the PUSCH is the plurality of PUSCH instances. The operation method of the terminal transmitted in the remaining PUSCH instances excluding one or more PUSCH instances. The method according to claim 1,
The control information includes third information indicating a structure of one or more slots included in the COT set by the base station, and the third information included in different control information received from the base station has the same slot structure. Indicating, the operating method of the terminal. As a method of operating a base station in a communication system,
Generating first information indicating one or more physical uplink shared channel (PUSCH) interlaces set in the unlicensed band;
Transmitting control information including the first information to a terminal; And
And receiving a PUSCH from the terminal through frequency resources corresponding to the one or more PUSCH interlaces in the unlicensed band. The method of claim 15,
The first information is a bitmap or an index, and the method of indicating the one or more PUSCH interlaces is different according to a subcarrier spacing of a bandwidth part (BWP) to which the one or more PUSCH interlaces belong. How it works. The method of claim 16,
The index includes information indicating a start PUSCH interlace among the one or more PUSCH interlaces and information indicating the number of the one or more PUSCH interlaces. The method of claim 15,
The control information further includes second information indicating one or more resource block (RB) sets set by the base station, each of the one or more RB sets includes one or more RBs, and the one or more RB sets are the A method of operating a base station, which is frequency resources of a channel occupancy time (COT) set by a base station. The method of claim 18,
When a plurality of RB sets are set by the base station, a guard band is located between the plurality of RB sets, and the PUSCH is mapped to one or more RBs belonging to the plurality of RB sets. The method of claim 18,
The PUSCH is received through the one or more PUSCH instances belonging to the one or more RB sets and the one or more PUSCH instances belonging to RBs other than the one or more RB sets, and the PUSCH in the one or more RB sets. The type of a listen before talk (LBT) operation performed for transmission is different from the type of the LBT operation performed for transmission of the PUSCH in RBs other than the one or more RB sets.

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