Method and apparatus for indicating channel occupancy time in wireless communication system

Abstract

A method performed by a user equipment (UE) for acquiring channel occupancy time information. The method comprises the following steps: receiving high-level signaling; detecting downlink control information (DCI) based on at least one of configuration information of a control resource set and configuration information of a search space set included in the higher layer signaling; identifying slot format indicator (SFI) information included in the DCI, the slot format indicator (SFI) information indicating a slot format of the at least one slot; and identifying a channel occupancy time of a base station (BS) based on the SFI information, where the SFI information includes information about a slot format combination of at least one slot.

Description

[0001] This application is a divisional application of an application with the application date of July 31, 2019 and the application number 201980051806.4, whose invention name is “Method and device for indicating channel occupancy time in a wireless communication system”. Technical Field

[0002] The present disclosure generally relates to methods and apparatus for transmitting and receiving data in a wireless communication system. Background Art

[0003] In order to meet the growing demand for increased wireless data traffic after the commercialization of the fourth generation (4G) communication system, efforts have been made to develop the fifth generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is called a communication system of "beyond 4G network" or a "long term evolution (LTE)" system.

[0004] To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency or millimeter wave (mmWave) bands, such as the 60 GHz band. To reduce path loss and increase transmission distance in 5G communication systems in ultra-high frequency bands, various technologies such as beamforming, massive multiple-input multiple-output (mass MIMO), full-size MIMO (FD-MIMO), array antennas, analog beamforming, and large antennas are being studied.

[0005] In order to improve the system network of the 5G communication system, various technologies such as evolved small cells, advanced small cells, cloud radio access networks (Cloud-RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communication, multi-point coordination (CoMP), and interference cancellation have been developed. In addition, for the 5G communication system, advanced coding modulation (ACM) techniques such as hybrid frequency shift keying (FSK) quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC) and advanced access technologies such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) have been developed.

[0006] The Internet has evolved into the Internet of Things (IoT), in which distributed elements such as objects exchange information with each other to process information. The Internet of Everything (IoE) technology has emerged, in which IoT technology is combined with technology for processing big data, such as by connecting to a cloud server. In order to realize the IoT, various technical elements are required, such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, so that in recent years, technologies related to sensor networks for connecting objects, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been studied. In the IoT environment, smart Internet technology (IT) services can be provided to collect and analyze data obtained from connected objects to create new value in human life. With the integration and combination of existing information technology and various industries, IoT can be applied to various fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0007] Attempts are being made to apply 5G communication systems to IoT networks. For example, technologies related to sensor networks, M2M communications, and MTC are being implemented by using 5G communication technologies, including beamforming, MIMO, and array antennas. The application of Cloud Radio Access Network (Cloud-RAN), which is the above-mentioned big data processing technology, can be an example of the fusion of 5G communication technology and IoT technology.

[0008] Since various services can be provided based on the above-mentioned technical features and the development of wireless communication systems, a method for efficiently providing these services is required. Summary of the invention

[0009]

Technical solution

[0010] According to an aspect of the exemplary embodiments, there is provided a communication method in wireless communication.

[0011] According to another aspect of the present disclosure, a method for acquiring channel occupancy time information performed by a user equipment (UE) is provided. The method includes: receiving high-layer signaling; detecting downlink control information (DCI) based on at least one of configuration information of a control resource set (CORESET) and configuration information of a search space set included in the high-layer signaling; identifying slot format indicator (SFI) information included in the DCI, the slot format indicator (SFI) information indicating a slot format of at least one slot; and identifying a channel occupancy time of a base station (BS) based on the SFI information, wherein the SFI information includes information about a slot format combination of at least one slot.

[0012] According to another aspect of the present disclosure, a user equipment UE for obtaining channel occupancy time information is provided, wherein the UE includes a transceiver and a processor. The processor is configured to execute the above method.

[0013] According to another aspect of the present disclosure, a method for indicating a channel occupancy time performed by a base station (BS) is provided. The method includes: sending a high-layer signaling to a user equipment (UE); performing a channel access procedure to occupy a channel; and during the channel occupancy time, based on at least one of the configuration information of a control resource set (CORESET) and the configuration information of a search space set included in the high-layer signaling, sending downlink control information (DCI) including a slot format indicator (SFI) information indicating a slot format of at least one slot, wherein the SFI information includes information about a slot format combination of at least one slot.

[0014] According to another aspect of the present disclosure, a base station BS for indicating channel occupation time is provided, wherein the BS includes a transceiver and a processor. The processor is configured to execute the above method.

[0015]

Beneficial Effects

[0016] Aspects of the present disclosure provide an efficient communication method in a wireless communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0018] Figure 1 is a diagram showing a structure of uplink / downlink (UL / DL) time-frequency domain transmission in a New Radio (NR) system according to an embodiment;

[0019] Figure 2 shows a channel access process in an unlicensed band according to an embodiment;

[0020] Figure 3 A DL or UL scheduling method and resource region in an NR system according to an embodiment are shown;

[0021] Figure 4 Slot Format Indicator (SFI) information in an NR system according to an embodiment is shown.

[0022] Figure 5 is a diagram for describing a period of providing SFI information according to an embodiment;

[0023] Figure 6 is a diagram for describing a period of providing SFI information according to an embodiment;

[0024] Figure 7 is a diagram for describing the number of time slots whose time slot format is indicated, the number being included in SFI information according to an embodiment;

[0025] Figure 8 is a diagram for describing offset information according to an embodiment;

[0026] Fig. 9 is a diagram for describing effective time slot information according to an embodiment;

[0027] Fig.10 is a flowchart of the operation of a BS according to an embodiment;

[0028] Fig.11 is a flowchart of the operation of a UE according to an embodiment;

[0029] Fig.12 is a flowchart of a method of indicating a channel occupancy time (COT) performed by a BS according to an embodiment;

[0030] Fig.13 is a flowchart of a method for obtaining COT information performed by a UE according to an embodiment;

[0031] Fig.14 is a block diagram showing a structure of a BS according to an embodiment; and

[0032] Fig.15 is a block diagram showing the structure of a UE according to an embodiment. DETAILED DESCRIPTION

[0033] The present disclosure has been made to address the above-mentioned problems and disadvantages, and to provide at least the advantages described below.

[0034] According to one aspect of the present disclosure, a method for indicating the channel occupancy time of an unlicensed frequency band performed by a base station (BS), the method comprising: sending physical downlink control channel (PDCCH) configuration information to a user equipment (UE); performing a channel access process to occupy a channel of the unlicensed frequency band; and based on the PDCCH configuration information, sending time slot format indicator information about at least one time slot within the channel occupancy time occupied by performing the channel access process, wherein the time slot format indicator information is determined based on at least one of the maximum channel occupancy time of the BS or the channel occupancy time occupied by performing the channel access process.

[0035] The slot format indicator information may be determined based on at least one of a maximum channel occupation time of the base station or a channel occupation time occupied by performing a channel access procedure.

[0036] The PDCCH configuration information may include at least one of size information about the slot format indicator information or transmission period information about the slot format indicator information.

[0037] The time slot format indicator information can be sent in the earliest time slot or the earliest symbol within the channel occupation time occupied by performing the channel access process, and the transmission period of the time slot format indicator information within the channel occupation time is applied based on the earliest time slot or the earliest symbol.

[0038] The method may further include: separately from the transmission period of the time slot format indicator information, additionally transmitting the time slot format indicator information in the earliest time slot or the earliest symbol within the channel occupation time occupied by performing the channel access procedure.

[0039] The slot format indicator information may include information indicating a slot format of time slots, the number of which is determined based on a maximum channel occupancy time of the BS.

[0040] The slot format indicator information may include information on a type or pattern of symbols included in at least one slot determined based on the channel occupancy time.

[0041] The slot format indicator information may include information indicating a slot format of a slot before or after a predetermined interval with respect to a slot in which the slot format indicator information is transmitted.

[0042] The slot format indicator information may include information indicating the slot format of a predetermined number of slots starting from the slot in which the slot format indicator information is transmitted.

[0043] The method may further include transmitting offset information indicating a difference between a time slot in which the slot format indicator information is transmitted and a first time slot whose slot format is indicated by the slot format indicator information.

[0044] The time slot format indicator information may indicate that the format of the time slot outside the channel occupancy time or the format of at least one symbol in the time slot outside the channel occupancy time is flexible.

[0045] The method may further include: sending at least one of offset information or valid time slot information, wherein the offset information indicates the difference between the time slot in which the time slot format indicator information is sent and the first time slot whose time slot format is indicated by the time slot format indicator information, and the valid time slot information indicates which time slots among the time slots whose time slot format is indicated by the time slot format indicator information have valid time slot format information.

[0046] According to another aspect of the present disclosure, a method for obtaining channel occupancy time information about an unlicensed frequency band performed by a UE includes: receiving a PDCCH from a BS based on PDCCH configuration information; obtaining time slot format indicator information in the received PDCCH; and determining at least one of the maximum channel occupancy time or the channel occupancy time of the BS based on the time slot format indicator information.

[0047] The method may further include determining whether to perform at least one of uplink transmission or a channel access procedure based on a result of the determination.

[0048] The determining may include determining a maximum channel occupancy time based on the number of time slots whose time slot formats are indicated by the time slot format indicator information.

[0049] The determining may include determining the channel occupancy time based on a type or pattern of symbols included in at least one slot, the type or pattern being included in the slot format indicator information.

[0050] According to another aspect of the present disclosure, a base station for indicating a channel occupancy time of an unlicensed frequency band includes: a transceiver; and a processor, coupled to the transceiver and configured to: send PDCCH configuration information to a UE, perform a channel access procedure to occupy a channel of the unlicensed frequency band, and based on the PDCCH configuration information, send a time slot format indicator information about at least one time slot within the channel occupancy time occupied by performing the channel access procedure. The time slot format indicator information is determined based on at least one of a maximum channel occupancy time of the BS or a channel occupancy time occupied by performing the channel access procedure.

[0051] The slot format indicator information may be determined based on at least one of a maximum channel occupation time of the base station or a channel occupation time occupied by performing a channel access procedure.

[0052] The PDCCH configuration information may include at least one of size information about the slot format indicator information or transmission period information about the slot format indicator information.

[0053] The time slot format indicator information can be sent in the earliest time slot or the earliest symbol within the channel occupation time occupied by performing the channel access process, and the transmission period of the time slot format indicator information within the channel occupation time is applied based on the earliest time slot or the earliest symbol.

[0054] The slot format indicator information may include information indicating a slot format of time slots, the number of which is determined based on a maximum channel occupancy time of the base station.

[0055] The processor may be further configured to send at least one of offset information or valid time slot information, wherein the offset information indicates the difference between the time slot in which the time slot format indicator information is sent and the first time slot whose time slot format is indicated by the time slot format indicator information, and the valid time slot information indicates which time slots among the time slots whose time slot format is indicated by the time slot format indicator information have valid time slot format information.

[0056] According to another aspect of the present disclosure, a UE for obtaining channel occupancy time information about an unlicensed frequency band includes: a transceiver; and a processor, coupled to the transceiver and configured to receive a PDCCH from a BS based on PDCCH configuration information; obtain time slot format indicator information in the received PDCCH; and determine at least one of the maximum channel occupancy time or the channel occupancy time of the BS based on the time slot format indicator information.

[0057] The processor may be further configured to determine whether to perform at least one of uplink transmission or a channel access procedure based on a result of the determination.

[0058] [Invention method]

[0059] Various embodiments of the present disclosure are described with reference to the accompanying drawings. However, the various embodiments of the present disclosure are not limited to specific embodiments, and it should be understood that various modifications, equivalents and / or substitutions may be made to the embodiments described herein. With respect to the description of the accompanying drawings, similar components may be marked with similar reference numerals.

[0060] As used herein, the expressions "A or B", "at least one of A and B", "at least one of A or B", "one or more of A and B", and "one or more of A or B" may include any and all combinations of one or more of the associated listed items. Terms such as "A or B", "at least one of A and B", or "at least one of A or B" may refer to any and all situations including at least one A, including at least one B, or including both at least one A and at least one B.

[0061] In the accompanying drawings, some elements may be enlarged, omitted or roughly shown. In addition, the size of each element does not completely correspond to the actual size of the element. In each of the accompanying drawings, the same or corresponding elements are represented by the same reference numerals.

[0062] It will be understood that the blocks in the flowchart or the combination of flowcharts can be performed by computer program instructions. Since these computer program instructions can be loaded into a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, these instructions are executed by the processor of the computer or other programmable data processing device, creating a unit for performing the functions described in the flowchart blocks. The computer program instructions can be stored in a computer-usable or computer-readable memory that can guide a computer or another programmable data processing device to implement functions in a specific manner, and therefore the instructions stored in the computer-usable or computer-readable memory can also produce a manufactured article containing an instruction unit, which is used to perform the functions described in the flowchart blocks. The computer program instructions can also be loaded into a computer or another programmable data processing device, and therefore, when a series of operations are performed in a computer or other programmable data processing device, the instructions for operating the computer or another programmable data processing device by generating a computer-executed process can provide operations for performing the functions described in one or more flowchart blocks.

[0063] In addition, each block can represent a module, segment or part of a code, which includes one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative embodiments, the functions mentioned in the block may not occur in order. For example, depending on the function corresponding thereto, two consecutive blocks may also be executed simultaneously or in reverse order.

[0064] As used herein, the term "unit" means a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and performs a specific function. However, the term "unit" is not limited to software or hardware. A "unit" can be formed to be located in an addressable storage medium, or can be formed to operate one or more processors. Therefore, for example, the term "unit" can include components (e.g., software components, object-oriented software components, class components, and task components), processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, or variables. The functions provided by components and "units" can be combined into a smaller number of components and "units", or can be divided into additional components and "units". In addition, components and "units" can be embodied as one or more central processing units (CPUs) in a reproduction device or a security multimedia card. Moreover, in an embodiment of the present disclosure, a "unit" can include at least one processor. Throughout the specification, a layer can also be referred to as an entity.

[0065] The most common services of 5G systems may include enhanced mobile broadband (eMBB) services, ultra-reliable and low-latency communications (URLLC) services, massive machine type communications (mMTC) services, or evolved multimedia broadcast / multicast services (eMBMS). A system that provides URLLC services may be referred to as a URLLC system, and a system that provides eMBB services may be referred to as an eMBB system. In this regard, the terms "service" and "system" may be used interchangeably.

[0066] In such a communication system, a variety of services may be provided to users, and in order to provide the plurality of services to users, a method and apparatus for providing each service in the same time interval according to characteristics may be required.

[0067] In a wireless communication system such as an LTE system, an advanced LTE (LTE-A) system, or a 5G (or NR) system, a BS and a UE may be configured such that the BS transmits downlink control information (DCI) to the UE, the DCI including resource allocation information for transmitting a DL signal to be transmitted via a PDCCH. The UE receives at least one DL signal of the DCI (e.g., a channel state information reference signal (CSI-RS)), a physical broadcast channel (PBCH), or a physical downlink shared channel (PDSCH).

[0068] For example, the BS transmits DCI indicating that the UE is to receive the PDSCH in the subframe n via the PDCCH in the subframe n, and upon receiving the DCI, the UE receives the PDSCH in the subframe n based on the received DCI.

[0069] In addition, in an LTE, LTE-A or NR system, the BS and the UE may be configured such that the BS sends a DCI including UL resource allocation information to the UE via a PDCCH, so that the UE sends at least one UL signal of a UCI (e.g., a sounding reference signal (SRS), a UCI or a physical random access channel (PRACH)) or a PUSCH to the BS.

[0070] For example, the UE may receive UL transmission configuration information (or UL DCI or UL grant) from the BS via the PDCCH in subframe n, and may perform UL data channel transmission (hereinafter referred to as PUSCH transmission) according to a predefined time (e.g., n+4), a time configured by an upper layer signal (e.g., n+k), or according to UL signal transmission time indicator information included in the UL transmission configuration information.

[0071] In the case of transmitting a configured DL transmission from a BS to a UE via an unlicensed frequency band, or transmitting a configured UL transmission from a UE to a BS via an unlicensed frequency band, a transmitting device (BS or UE) may perform a channel access procedure or a listen-before-talk (LBT) procedure before or immediately before the start of the configured signal transmission on the unlicensed frequency band where the signal transmission is configured. Based on the result of performing the channel access procedure, when it is determined that the unlicensed frequency band is in an idle state, the transmitting device may access the unlicensed frequency band and then perform the configured signal transmission.

[0072] According to the result of the channel access process performed by the transmitting device, when it is determined that the unlicensed frequency band is not in an idle state or it is determined that the unlicensed frequency band is in an occupied state, the transmitting device cannot access the unlicensed frequency band, and thus may not be able to perform the configured signal transmission. Generally, in the channel access process for the unlicensed frequency band configured for signal transmission, the transmitting device can determine the idle state of the unlicensed frequency band by receiving a signal in the unlicensed frequency band during a predetermined time or a time calculated according to a predefined rule (for example, a time calculated using a random value selected by the BS or UE), and then the strength of the received signal can be compared with a threshold value predefined or calculated by using a function of at least one parameter, the at least one parameter including the channel bandwidth, the bandwidth of the signal to be transmitted, the strength of the transmission power, or the beam width of the transmission signal.

[0073] For example, when the strength of the signal received by the transmitting device within 25 microseconds (μs) is less than -72 decibel-milliwatt (dBm), that is, a predetermined threshold, the transmitting device can determine that the unlicensed frequency band is in an idle state, and thus the configured signal transmission can be performed. In this regard, the maximum available time for signal transmission can be limited based on the maximum channel occupancy time in the unlicensed frequency band defined based on each country or region or the type of transmitting device (e.g., BS, UE, master device or slave device). For example, in Japan, a BS or UE in 5GHz of an unlicensed frequency band can perform a channel access process, and then can transmit a signal by occupying the channel within a maximum of 4ms without additionally performing a channel access process. When the strength of the signal received by the transmitting device during 25μs is greater than -72dBm (which is a predefined threshold), the BS can determine that the unlicensed frequency band is not in an idle state and can not transmit a signal.

[0074] For 5G communication systems, various technologies for providing various services and supporting high data transmission rates may be introduced, including retransmission in units of code block groups or transmission of UL signals without UL scheduling information. Therefore, in order to perform 5G communication via an unlicensed band, a more efficient channel access process based on various parameters is required.

[0075] Wireless communication systems providing voice-centric services have been developed, and broadband wireless communication systems providing high-speed, high-quality packet data services have been developed, such as High Speed ​​Packet Access (HSPA), LTE or Evolved Universal Terrestrial Radio Access (E-UTRA), 3GPP's LTE-A and LTE-Pro, 3GPP2's High Rate Packet Data (HRPD) Ultra Mobile Broadband (UMB), or the Institute of Electrical and Electronics Engineers (IEEE)'s 802.16e. 5G or NR communication standards are being established for 5G wireless communication systems.

[0076] In a wireless communication system including 5G, at least one of the services including eMBB, mMTC and URLLC may be provided to a UE. The services may be provided to the same UE in the same time interval. According to an embodiment of the present disclosure, the eMBB service may be used to transmit large-capacity data at high speed, the mMTC service may be used to minimize the power of the terminal and allow multiple terminals to access, and the URLLC service may be high reliability and low latency. These three services may be the main services in an LTE system or a post-LTE system (e.g., 5G or NR / next radio system).

[0077] When BS data corresponding to an eMBB service is scheduled to a certain UE in a transmission time interval (TTI), and then a situation occurs in which URLLC data is sent in the TTI, a portion of the eMBB data may not be sent in a frequency band in which the scheduled eMBB data is being sent, and the URLLC data may be sent on that frequency band. The UE for which eMBB has been scheduled and the UE for which URLLC has been scheduled may be the same UE or a different UE. In the aforementioned example, part of the eMBB data that has been scheduled and is being sent is not sent, and therefore, the possibility of eMBB data loss increases. Therefore, for a UE for which eMBB has been scheduled or a UE for which URLLC has been scheduled, it may be beneficial to define a method for processing a received signal and a method for receiving a signal.

[0078] BS is an entity that allocates resources of the terminal, and may be at least one of an evolved Node B (eNode B or eNB), a Node B, a BS, a wireless access unit, a BS controller, or a node on a network. Examples of terminals may include UEs, mobile stations (MS), cellular phones, smart phones, computers, or multimedia systems that can perform communication functions. DL may refer to the transmission path of a wireless signal from a BS to a UE, and UL may refer to the transmission path of a wireless signal from a UE to a BS. Although the following description may be provided for an LTE or LTE-A system, the embodiments of the present disclosure are also applicable to other communication systems with similar technical backgrounds or channel structures. For example, the embodiments of the present disclosure are also applicable to 5G (or NR) communication systems developed after the LTE-A system. In addition, without greatly departing from the scope of the present disclosure, by the judgment of a person of ordinary skill in the art, the embodiments of the present disclosure may be applied to other communication systems by modification.

[0079] As a representative example of a broadband wireless communication system, the NR system adopts an orthogonal frequency division multiplexing (OFDM) scheme in DL, and an OFDM scheme and a single carrier frequency division multiple access (SC-FDMA) scheme in UL. UL refers to a radio link through which a UE (also called a terminal) or an MS sends data or a control signal to a BS (e.g., an eNB), while DL refers to a radio link through which a BS sends data or a control signal to a terminal. By allocating and operating time-frequency resources on which data or control information is to be carried for each user, the multiple access scheme can distinguish between data and control information for each user so that the time-frequency resources do not overlap with each other. That is, orthogonality is established.

[0080] The NR system adopts a hybrid automatic repeat request (HARQ) scheme, which retransmits data in the physical layer when decryption fails in the initial transmission of the data. The HARQ scheme indicates that when the receiver fails to accurately decrypt (decode) the data, the receiver sends information indicating the decoding failure (i.e., negative acknowledgment (NACK)) to the transmitter to allow the transmitter to resend the data in the physical layer. The receiver improves data reception performance by combining the data retransmitted by the transmitter with the data that failed to be decoded previously. When the receiver accurately decodes the data, the receiver can send information indicating the decoding success (i.e., acknowledgment (ACK)) to the transmitter to allow the transmitter to send new data.

[0081] The present disclosure provides a method and apparatus for indicating channel occupancy time. A description is provided for a method for sending and receiving information about channel occupancy time and a time slot format indicator in the channel occupancy time, the method being performed by a node to receive a DL signal or by a system and a node to send an UL signal via an unlicensed frequency band in a wireless communication system. The present disclosure provides a method for sending information about the channel occupancy time of a transmitting device and a time slot format indicator indicating a time slot configuration in the channel occupancy time, the method being performed by a node to receive a DL signal or by a system and a node to send an UL signal via an unlicensed frequency band in a wireless communication system; and a method for determining the channel occupancy time and the time slot configuration, the method being performed by a node that receives the information and the time slot format indicator.

[0082] Figure 1 2 is a diagram showing a basic structure of a time-frequency domain according to an embodiment, where the time-frequency domain is a wireless resource region for transmitting data or a control channel from UL or DL ​​of an NR system or a system similar to the NR system.

[0083] refer to Figure 1 , the horizontal axis represents the time domain in the wireless resource area, and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain can be an OFDM symbol or a discrete Fourier transform spread OFDM (DFT-s-OFDM) symbol, and N symb OFDM symbols or N symb DFT-s-OFDM symbols 101 are used to form a time slot 102.

[0084] OFDM symbols can be used to send and receive signals according to an OFDM multiplexing scheme, and DFT-s-OFDM symbols can be used to send and receive signals according to a DFT-s-OFDM multiplexing scheme or a single carrier frequency division multiple access (SC-FDMA) multiplexing scheme. In the following, for ease of description, there is no distinction between OFDM symbols and DFT-s-OFDM symbols, so they are collectively referred to as OFDM symbols, and will now be described with reference to the reception and transmission of DL signals, but it can also be applied to the reception and transmission of UL signals.

[0085] When the interval between subcarriers is 15kHz, one time slot 102 can constitute one subframe 103, and the lengths of the time slot 102 and the subframe 103 can be 1ms respectively. The number of time slots 102 constituting one subframe 103 and the length of the time slot 102 can vary according to the interval between subcarriers. For example, when the interval between subcarriers is 30kHz, two time slots 102 can be concentrated to constitute one subframe 103. In this case, the length of the time slot 102 is 0.5ms, and the length of the subframe 103 is 1ms. The radio frame 104 can be a time domain period consisting of 10 subframes. The smallest transmission unit in the frequency domain is the subcarrier, and the bandwidth of the entire system transmission frequency band is N. sc BW It consists of 105 subcarriers.

[0086] However, numerical values ​​such as the interval between subcarriers, the number of time slots 102 included in the subframe 103, the length of the time slot 102, or the length of the subframe 103 may be variably applied. For example, in the LTE system, the interval between subcarriers is 15 kHz, two time slots 102 are aggregated to constitute one subframe 103, in which case the length of the time slot 102 is 0.5 ms, and the length of the subframe 103 is 1 ms.

[0087] The basic unit of resources in the time-frequency domain is a resource element (RE) 106 and can be represented as a symbol index and a subcarrier index. A resource block (RB) or a physical resource block (PRB) 107 can be defined as N in the time domain. symb consecutive OFDM symbols 101 and N in the frequency domain SC RB 108. Therefore, one RB 107 in one time slot may include RE=N symb ×N SC RB Usually, the minimum data allocation unit in the frequency domain is RB107. In the NR system, N symb It can be 14, N SC RB It can be 12, and RB (N) can be changed according to the bandwidth of the system transmission band. RB ) number. In the LTE system, N symb It can be 7, N SC RB It can be 12, and N can be changed based on the bandwidth of the system transmission band RB .

[0088] DCI can be sent within the first N OFDM symbols in a subframe. N can be {1, 2, 3}, and the UE can be configured by the BS for the number of symbols over which DCI can be sent via the upper signal. In addition, based on the amount of control information to be sent in the current time slot, the BS can change the number of symbols over which DCI can be sent from the time slot for each time slot, and information about the number of symbols can be sent to the UE via a separate DL control channel.

[0089] In the NR or LTE system, scheduling information about DL data or UL data in DCI can be sent from the BS to the UE. DCI can be defined in various formats, and can indicate whether the scheduling information is UL data scheduling information (UL grant) or DL ​​data scheduling information (DL grant), whether the DCI is a compact DCI with small-size control information, whether the control information is a fall-back DCI, whether spatial multiplexing using multiple antennas is applied, or whether the DCI is a DCI for controlling power according to each format. For example, a DCI format (e.g., DCI format 1_0 of NR) as scheduling control information (DL grant) for DL ​​data may include at least one of the following multiple control information:

[0090] - DCI format identifier: an identifier that identifies the received DCI format.

[0091] - Frequency domain resource allocation: This indicates the RBs allocated for data transmission.

[0092] - Time domain resource allocation: This indicates the time slots and symbols allocated for data transmission.

[0093] - Virtual Resource Block (VRB)-to-PRB mapping: indicates whether the VRB mapping scheme is used.

[0094] - Modulation and Coding Scheme (MCS): This indicates the modulation scheme used for data transmission and the size of a transport block (TB) which is data to be transmitted.

[0095] - New Data Indicator: This indicates whether the HARQ transmission is an initial transmission or a retransmission.

[0096] - Redundancy Version: This indicates the redundancy version of HARQ.

[0097] -HARQ process number: This indicates the process number of HARQ.

[0098] -PDSCH allocation information (DL allocation index): This indicates to the UE the number of PDSCH reception results to be reported to the BS.

[0099] - Transmit Power Control (TPC) Command for Physical Uplink Control Channel (PUCCH): This indicates a transmit power control command for PUCCH which is a UL control channel.

[0100] - PUCCH resource indicator: This indicates the PUCCH resource to be used in the HARQ-ACK report, including the result of receiving the PDSCH set via the corresponding DCI.

[0101] -PUCCH transmission timing indicator (PDSCH-to-HARQ_feedback timing indicator): It indicates information on a time slot or symbol on which a PUCCH is to be transmitted, wherein the PUCCH is used for HARQ-ACK reporting including a result of receiving a PDSCH set via a corresponding DCI.

[0102] DCI may be transmitted through a PDCCH (or control information, hereinafter used interchangeably) or an enhanced PDCCH (EPDCCH) (or enhanced control information, hereinafter used interchangeably) which is a DL physical control channel after undergoing a channel coding and / or modulation process.

[0103] Typically, for each terminal, the DCI is independently scrambled by a specific radio network temporary identifier (RNTI) or terminal identifier (C-RNTI). The DCI is added with a cyclic redundancy check (CRC), channel coded, and then configured as an independent PDCCH to be sent. In the time domain, the PDCCH is mapped and sent in the control channel transmission period. The mapping position of the PDCCH in the frequency domain can be determined by the identifier (ID) of each terminal, and the PDCCH can be sent through the transmission bandwidth of the entire system.

[0104] DL data may be transmitted through a PDSCH which is a physical channel for transmitting DL data. The PDSCH may be transmitted after a control channel transmission period, and scheduling information such as a specific mapping position or a modulation scheme in a frequency domain may be determined based on a DCI to be transmitted through a PDCCH.

[0105] The BS notifies the UE of the modulation scheme applied to the PDSCH to be transmitted and the transport block size (TBS) to be transmitted by using the MCS included in the control information constituting the DCI. The MCS may consist of 5 bits, or may consist of more or less bits than 5 bits. The TBS corresponds to the size of the BS before channel coding for error correction is applied to the TB to be transmitted by the BS.

[0106] The modulation schemes supported in the NR system are quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (16QAM), 64QAM or 256QAM, and the corresponding modulation orders (Qm) correspond to 2, 4 and 6, respectively. In the case of QPSK modulation, 2 bits can be transmitted per symbol, in the case of 160QAM modulation, 4 bits can be transmitted per symbol, in the case of 64QAM modulation, 6 bits can be transmitted per symbol, and in the case of 256QAM modulation, 8 bits can be transmitted per symbol. In addition, according to system modification, a modulation scheme of 256QAM or higher can be used.

[0107] In the NR system, UL / DL HARQ adopts an asynchronous HARQ scheme in which the data retransmission time is not fixed. Describing the example of DL, when HARQ NACK about the initially transmitted data transmitted by the BS is fed back from the UE, the BS can freely determine the transmission time of the retransmitted data through the scheduling operation. The UE buffers the data determined to be erroneous as a result of decoding the received data as a result of the HARQ operation, and then combines it with the next retransmission data. The HARQ ACK / NACK information of the PDSCH transmitted in the subframe nk can be transmitted from the UE to the BS via the PUCCH or PUSCH in the subframe n.

[0108] In a 5G communication system such as an NR system, the k value may be included in a DCI for indicating or scheduling the reception of a PDSCH sent in a subframe nk and then sent, or may be configured in the UE based on an upper layer signal. In this regard, the BS may configure one or more k values ​​as an upper layer signal, and may indicate a specific k value by using DCI. Therefore, k may be determined based on the HARQ-ACK processing capability of the UE, that is, the minimum time required for the UE to receive the PDSCH and then generate and report the HARQ-ACK regarding the PDSCH. In addition, before configuring the k value in the UE, the UE may use a predefined value or a default value.

[0109] A description of a wireless communication system, method, and apparatus provided by an embodiment of the present disclosure is provided with respect to an NR system, but the present disclosure is not limited to an NR system and can be applied to various wireless communication systems including LTE, LTE-A, LTE-A-Pro, and 5G systems. In addition, a description of the present disclosure is provided with reference to a system and an apparatus for transmitting and receiving signals by using an unlicensed frequency band, but the description of the present disclosure can also be applied to a system operating in a licensed frequency band.

[0110] Hereinafter, in the present disclosure, upper layer signaling or an upper layer signal may be a signal transmission method in which a BS transmits a signal to a UE by using a DL data channel of a physical layer or a UE transmits a signal to a BS by using an UL data channel of a physical layer, and may indicate a method of transmitting a signal by upper layer signaling (or an upper layer signal) including a radio access control (RRC) signaling or a PDCP signaling or a medium access control control element (MAC CE). In addition, the upper layer signaling or the upper layer signal may include system information that is generally transmitted to a plurality of UEs, such as a system information block (SIB).

[0111] In a system that performs communication in an unlicensed frequency band, a transmitting device (BS or UE) that transmits a signal via the unlicensed frequency band may perform a channel access procedure or LBT on the unlicensed frequency band that is a communication target before signal transmission, and when it is determined according to a result of the channel access procedure that the unlicensed frequency band is in an idle state, the transmitting device may access the unlicensed frequency band and may perform signal transmission. According to a result of the channel access procedure, when it is determined that the unlicensed frequency band is not in an idle state, the transmitting device may not be able to perform signal transmission.

[0112] During the channel access process regarding an unlicensed frequency band, the transmitting device may determine the idle state of the unlicensed frequency band by receiving a signal in the unlicensed frequency band within a fixed time or a time calculated according to a predetermined rule (the time calculated using a random value selected by the BS or UE), and then compare the strength of the received signal with a threshold value, which is predefined or calculated by using a function of at least one parameter including the channel bandwidth, the bandwidth of the signal to be transmitted, the strength of the transmitted power, or the beam width of the transmitted signal.

[0113] For example, the transmitting device may measure the signal strength Xμs (e.g., 25μs) immediately before the time of transmitting the signal and when the measured signal strength is less than a predetermined or calculated threshold value T (e.g., -72dBm), the transmitting device may determine that the unlicensed frequency band is in an idle state, and thus the configured signal may be transmitted. In this regard, the maximum available time for continuous signal transmission after the channel access process may be limited according to the maximum channel occupancy time in the unlicensed frequency band defined according to each country, each region, or each frequency band, or the maximum available time for continuous signal transmission after the channel access process may be limited according to the type of the transmitting device (e.g., BS or UE, or master device or slave device). For example, in Japan, a BS or UE in 5GHz of the unlicensed frequency band may transmit a signal by occupying a channel for a maximum of 4ms without additionally performing a channel access process on the unlicensed frequency band that has been determined to be in an idle state according to the result of the channel access process.

[0114] In detail, when a BS or a UE attempts to transmit a DL signal or a UL signal via an unlicensed band, a channel access procedure performed by the BS or the UE may be divided into the following types.

[0115] - Type-1: A variable time channel access procedure is performed and then a UL / DL signal is transmitted.

[0116] - Type-2: A channel access procedure is performed within a fixed time, and then a UL / DL signal is transmitted.

[0117] - Type-3: A UL signal or a DL signal is transmitted without performing a channel access procedure.

[0118] Both the case where the BS sends a DL signal to the UE via an unlicensed frequency band and the case where the UE sends a UL signal to the BS via an unlicensed frequency band are described, but the embodiments of the present disclosure can be equally applied or modified, and then the embodiments of the present disclosure can be applied according to the case where the UE sends a UL signal to the BS via an unlicensed frequency band and the case where the BS sends a DL signal to the UE via an unlicensed frequency band. Therefore, a detailed description of the sending and receiving of DL signals is not provided. In addition, it is assumed that one DL data information (codeword or TB) or UL data information is exchanged between the BS and the UE. However, the embodiments of the present disclosure are also applicable to the case where the BS sends a DL signal to multiple UEs or the case where multiple codewords or TBs are exchanged between the BS and the UE.

[0119] A transmitting node (hereinafter referred to as a BS or UE) attempting to perform signal transmission via an unlicensed frequency band may determine a channel access procedure scheme according to the type of signal to be transmitted. For example, when the BS attempts to transmit a DL signal including a DL data channel via an unlicensed frequency band, the BS may perform a type-1 or type-3 channel access procedure. When the BS attempts to transmit a DL signal that does not include a DL data channel through an unlicensed frequency band, for example, when the BS attempts to transmit a synchronization signal or a DL control channel, the BS may perform a type-2 channel access procedure and may transmit a DL signal.

[0120] In this regard, the channel access process scheme can be determined based on the transmission length of the signal to be sent via the unlicensed frequency band, or the duration of the time or period during which the unlicensed frequency band is occupied and used. Typically, a type-1 or type-3 scheme may require a longer channel access process than a channel access process based on a type-2 scheme. Therefore, when a signal is sent in a short time period or a time period equal to or less than a reference time (e.g., X ms or Y symbols), a type-2 channel access process can be performed. However, when a signal is sent in a longer time period or a time period equal to or greater than a reference time (e.g., X ms or Y symbols), a type-1 or type-3 channel access process can be performed. In other words, channel access processes according to different types can be performed within the available time of the unlicensed frequency band.

[0121] When performing a type-1 or type-3 channel access procedure based on the aforementioned reference, the sending node may determine a channel access priority level based on a quality of service level identifier (QCI) of a signal to be sent via an unlicensed band, and may perform a channel access procedure based on the determined channel access priority level by using at least one of the predefined configuration values ​​provided in Table 1.

[0122] For example, QCI 1, 2, and 4 indicate QCI values ​​for corresponding services, such as conversational voice, conversational video (real-time stream), and non-conversational video (buffered stream). When a signal is transmitted over an unlicensed band, the signal is for a service that does not match the QCI of Table 1, the transmitting node may select the service and the QCI of Table 1 that is most relevant to the service, and may select a channel access priority level for the selected QCI.

[0123] Table 1 shows the mapping relationship between channel access priority levels and QCIs.

[0124]

Table 1

[0125] Channel access priority QCI 1 1,3,5,65,66,69,70 2 2,7 3 4,6,8,9 4 -

[0126] Depending on the delayed time period (delay duration), a set of values ​​or sizes of the contention window (CW_p), the minimum and maximum values ​​of the contention window (CW_min, p and CW_max, p) or the available maximum channel occupancy time (T_mcot, p) based on the channel access priority level (p) can be determined according to Table 2 below.

[0127] In other words, when the BS attempts to send a DL signal via an unlicensed band, the BS performs a channel access procedure on the unlicensed band during a time equal to T_f+m_p*T_sl. When the channel access procedure is performed with p=3 as the channel access priority level, the delay time value required to perform the channel access procedure is set according to the formula of T_f+m_p*T_sl (where m_p=3). In this regard, T_f is a value fixed to 16us, and the time of T_sl must be an idle state. In the time after time T_sl in time T_f (i.e., time T_f-T_sl), the BS may not perform the channel access procedure. Even when the BS performs the channel access procedure at the time of T_f-T_sl, the result of the channel access procedure is not used. In other words, time T_f-T_sl refers to the time when the BS postpones performing the channel access procedure.

[0128] When it is determined that the unlicensed band is in a constant idle state during the time m_p*T_sl, N=N-1 is possible. In this regard, at the time point of performing the channel access process, N is selected as a random integer value between 0 and the CW_p value. In the case where the channel access priority level is 3, the minimum contention window value and the maximum contention window value are 15 and 63, respectively. When it is determined that the unlicensed band is in an idle state during the delay duration and the period of the additional channel access process, the BS can send a signal during the T_mcot,p time (i.e., 8ms). Table 2 shows the channel access priority levels in DL. For ease of description, the present disclosure will be described by using DL channel access priority levels, but for UL, the channel access priority levels of Table 2 can be reused, or the channel access priority levels can be defined separately for UL, and the channel access priority levels defined separately for UL can be used.

[0129]

Table 2

[0130]

[0131] The initial CW_p value is the minimum contention window value (CW_min, p). The BS selecting the value of N may perform a channel access procedure in a time of T_sl, and when the BS determines that the unlicensed frequency band is in an idle state through the channel access procedure performed in a time of T_sl, the BS may change the value to N=N-1, and when N=0, the BS may transmit a signal during a maximum time of T_mcot, p via the unlicensed frequency band. When the unlicensed frequency band determined by the channel access procedure at a time of T_sl is not in an idle state, the value of N may not be changed, and the channel access procedure may be performed again.

[0132] The CW_p value may be changed at a time point when the BS initiates the channel access procedure, at a time point when the BS selects a value of N to perform the channel access procedure, or based on a reception result of a DL data channel in a reference subframe or a reference time slot in a transmission period (or maximum channel occupancy time (MCOT)) in which the BS recently transmits DL through an unlicensed band, immediately before the time point when the BS initiates the channel access procedure or the time point when the BS selects a value of N to perform the channel access procedure. In other words, the BS receives a report on a reception result of DL data transmitted in a reference subframe or a reference time slot from the UE, and may increase or minimize CW_p based on a ratio (Z) of NACK in a reception report of the reception result.

[0133] Figure 2 A channel access procedure in an unlicensed band according to an embodiment is shown.

[0134] refer to Figure 2 , the time point when the BS initiates the channel access process 270, the time point when the BS selects the value of N to perform the channel access process, or the first transmission period 240 (hereinafter, time slot or subframe) of the transmission period 230 in which a DL signal was most recently transmitted through the unlicensed frequency band immediately before the time point when the BS initiates the channel access process 270 or the time point when the BS selects the value of N to perform the channel access process becomes the contention window change reference time slot of the channel access process 270.

[0135] When the BS cannot receive a report on the reception result of the DL data channel sent in the first time slot 240 of the transmission period 230, for example, when the time interval between the first subframe and the time point when the BS starts the channel access process 720 is equal to or less than n time slots or subframes (i.e., when the BS starts the channel access process before the UE can report the reception result of the DL data channel sent in the first time slot 240), the first subframe of the transmission period in which the DL signal was most recently sent before the DL signal transmission period 230 becomes the reference subframe.

[0136] In other words, the time point at which the BS starts the channel access procedure 270, the time point at which the BS selects the value of N to perform the channel access procedure, or in the case where the BS does not receive a reception result from the UE regarding the DL data transmitted immediately before it in the reference subframe 240, the BS can determine the first subframe of the transmission period of the most recently transmitted DL signal as the reference frame from the reception result regarding the DL data channel previously received from the UE. Then, the BS can determine the CW_p value used in the channel access procedure 270 by using the DL data reception result received from the UE regarding the DL data transmitted via the DL data channel in the reference subframe.

[0137] For example, when a BS that sends a DL signal after a channel access procedure (e.g., CW_p=15) configured according to a channel access priority level of 3 (p=3) determines that 80% of the reception results received from the UE regarding the DL data sent from the BS to the UE via the DL data channel in the first subframe are NACKs among the DL signals sent via the unlicensed frequency band, the BS may increase the CW_p value from the initial value (CW_p=15) to the next CW_p value (CW_p=31).

[0138] In this regard, when the BS determines that at least 80% of the reception results are not NACK, the BS may maintain the CW_p value as the current value, or may change the CW_p value to the initial CW_p value. In this regard, the change of CW_p may be applied jointly to all channel access priority levels, or may be applied only to the channel access priority level used in the channel access process. In this regard, a method for determining a Z value is provided. That is, a method for determining a reception result performed by a BS is provided, which effectively determines the CW_p value in a reference subframe or reference time slot for determining whether to change the CW_p value. The reception result is derived from the reception result regarding the DL data sent via the DL data channel and is sent or reported to the BS by the UE.

[0139] When the BS sends one or more codewords or TBs to one or more UEs in a reference subframe or reference time slot, the BS may determine the Z value as the ratio of NACKs in the reception results of the TBs received in the reference subframe or reference time slot sent or reported by the one or more UEs. For example, when two codewords or two TBs are sent to the UE in a reference subframe or reference time slot, the BS may receive transmissions or two reports of DL data signal reception results of the two TBs from the UE. When the ratio of NACK (Z) in the two reception results is equal to or greater than a threshold value (e.g., Z=80%) predefined or set between the BS and the UE, the BS may change or increase the contention window value.

[0140] In this regard, when the UE performs bundling on DL data reception results regarding one or more subframes (e.g., M subframes) including a reference subframe or a reference slot, and transmits or reports the results thereof to the BS, the BS may determine that the UE has transmitted the M reception results. The BS may then determine the ratio of NACKs among the M reception results as a Z value, and may change, maintain, or initialize the CW_p value.

[0141] When the reference subframe is the reception result regarding the second time slot among the two time slots constituting one subframe, the BS can determine the ratio of NACK in the reception result regarding DL data received in the reference subframe (in other words, the second time slot) and the next subframe, which is sent or reported by the UE to the BS, as the Z value.

[0142] In addition, in the case where scheduling information or DL ​​control information about a DL data channel to be transmitted by the BS is transmitted in the same cell or frequency band as the cell or frequency band in which the DL data channel is transmitted, or in the case where scheduling information or DL ​​control information about a DL data channel to be transmitted by the BS is transmitted in an unlicensed band but in a cell or frequency band different from the cell or frequency band in which the DL data channel is transmitted, the BS may determine the reception result from the UE as NACK, and thus may determine the Z value. In addition, when the BS determines that the UE does not transmit the reception result regarding the DL data received by the UE in the reference subframe or reference time slot, and when the BS determines that the reception result transmitted regarding the DL data transmitted by the UE is at least one of DTX, NACK / DTX, or any state, the BS may determine the reception result from the UE as NACK, and thus may determine the Z value.

[0143] Alternatively, in the case of transmitting scheduling information or DL ​​control information about a DL data channel to be transmitted by the BS in a permitted area, when the BS determines that the BS is in at least one of DTX, NACK / DTX, or any state regarding a reception result of DL data transmitted by the UE, the BS may not include the reception result from the UE in the Z value as a reference of the CW_p value. In other words, the BS may determine the Z value while ignoring the reception result from the UE.

[0144] In addition, in the case where scheduling information or DL ​​control information about a DL data channel is to be sent in a licensed frequency band, when the BS does not actually send DL data (no transmission), the BS can ignore the DL data reception results sent or reported by the UE from the DL data reception results about the reference subframe or reference time slot sent or reported by the UE to the BS, and can determine the Z value.

[0145] In the 5G system, it may be necessary to flexibly define and operate the frame structure according to various services and requirements. For example, depending on the requirements, the service may have different subcarrier spacings. In the current 5G communication system, in order to support multiple subcarrier spacings, the support may be determined by using the following formula (1).

[0146] △f=f 0 2 m ...(1)

[0147] f 0 indicates the default subcarrier spacing of the system, and m indicates the scaling factor, which is an integer. For example, when f 0When the frequency band is 15 kilohertz (kHz), the set of subcarrier spacings that a 5G communication system may have may consist of 3.75kHz, 7.5kHz, 15kHz, 30kHz, 60kHz, 120kHz, 240kHz, or 480kHz. The available set of subcarrier spacings may vary depending on the frequency band. For example, in a frequency band equal to or less than 6GHz, 3.75kHz, 7.5kHz, 15kHz, 30kHz, and 60kHz may be used, and in a frequency band equal to or greater than 6GHz, 60kHz, 120kHz, and 240kHz may be used.

[0148] The length of an OFDM symbol can vary depending on the spacing between the subcarriers that make up the OFDM symbol. This is because, due to the characteristics of the OFDM symbol, the spacing between the subcarriers and the length of the OFDM symbol have an inverse relationship. For example, when the spacing between the subcarriers is doubled, the length of the OFDM symbol is reduced by half, and conversely, when the spacing between the subcarriers is reduced by half, the length of the OFDM symbol is increased by two times (doubled).

[0149] Next, the resource region for sending data channels in the 5G communication system will be described.

[0150] Figure 3 A resource region for sending a data channel in a 5G communication system according to an embodiment is shown.

[0151] refer to Figure 3 , the UE monitors or searches for the PDCCH 310 in a DL control channel region (hereinafter, a control resource set (CORESET) to a search space (SS)) set by the BS through an upper layer signal. In this regard, the DL control channel region consists of time domain information 314 and frequency domain information 312, and the time domain information 314 can be configured according to a symbol unit, and the frequency domain information 312 can be configured according to an RB or an RB group.

[0152] When the UE detects the PDCCH 310 in the time slot i 300, the UE obtains the DCI transmitted via the detected PDCCH 310. The UE can obtain scheduling information about a DL data channel or a UL data channel based on the received DCI. In other words, the DCI may include information about a resource region (or a PDSCH transmission region) in which the UE is required to receive a DL data channel (hereinafter referred to as a PDSCH) transmitted from the BS, or information about a resource region allocated by the BS to the UE for transmitting a UL data channel (ie, a PUSCH).

[0153] A case where scheduling for transmission of a UL data channel (ie, PUSCH) is performed on a UE will now be described.

[0154] The UE receiving the DCI may determine the time slot index or offset information K for reception of the PUSCH based on the DCI, and may determine the PUSCH transmission time slot index. For example, according to the time slot index i 300 of the received PDCCH 310, the UE may determine, based on the offset information K, that the UE is scheduled to transmit the PUSCH in the time slot i+K 305. In this regard, the UE may also determine the time slot i+K 305 or the symbol or time at which the PUSCH is started in the time slot i+K 305 based on the offset information K according to the received CORESET of the received PDCCH 310.

[0155] Moreover, the UE may obtain PUSCH transmission time-frequency resource region information 325 and 330 in the PUSCH transmission time slot 305 from the DCI. The PUSCH transmission frequency resource region information 330 may include information about a PRB unit or a PRB group unit. The PUSCH transmission frequency resource region information 330 may be about a region included in an initial bandwidth (BW) or an initial BW part (BWP) determined by the UE or configured to the UE via an initial access procedure. When the BW or BWP is configured to the UE by using an upper layer signal, the PUSCH transmission frequency resource region information 330 may be a region included in the BW or BWP configured by the upper layer signal.

[0156] The PUSCH transmission time resource region information 325 may be information about a symbol unit or a symbol group unit, or may be information indicating absolute time information. The PUSCH transmission time resource region information 325 may be expressed as a combination of a PUSCH transmission start time, a symbol and a length of the PUSCH, a PUSCH transmission end time or a symbol, and may be included as a field or a value in the DCI. In this regard, the PUSCH transmission time resource region information 325 may be included in the DCI as a field or a value representing the PUSCH transmission start time, a symbol and a length of the PUSCH, a PUSCH transmission end time or each symbol, respectively. The UE may send a PUSCH in a PUSCH transmission resource region 340 determined based on the DCI.

[0157] In a 5G communication system, in order to dynamically change the DL signal transmission period and the UL signal transmission period in a time division duplex (TDD) system, the BS may indicate an SFI indicating whether each OFDM symbol constituting a time slot is a DL symbol, a UL symbol, or a flexible symbol. In this regard, a symbol indicated as a flexible symbol may not be a DL symbol or a UL symbol, or may be a symbol that can be changed to a DL symbol or a UL symbol according to control information or scheduling information specified by the UE. In this regard, a flexible symbol may include gap protection required for a change from DL to UL.

[0158] The SFI is simultaneously transmitted to a plurality of UEs via a UE (cell) group common control channel. In other words, the SFI is transmitted through a PDCCH scrambled by a CRC with an identifier (eg, SFI-RNTI) different from the C-RNTI.

[0159] The SFI may include information about N time slots, and the BS may configure the value of N to the UE from a set of values ​​by using an upper layer signal, wherein the set of values ​​is an integer or a natural number greater than 0, or a predefined available value, such as 1, 2, 5, 10, or 20. In addition, the BS may configure the size of the SFI to the UE using an upper layer signal. An example of a time slot format that the SFI may indicate is shown in Table 3 below.

[0160]

Table 3

[0161]

[0162]

[0163]

[0164]

[0165] In Table 3, D represents DL, U represents UL, and X represents flexible symbols. In Table 3, the total number of supportable slot formats is 256. In the current NR system, the maximum size of the SFI information bit is 128 bits, and the SFI information bit can be configured by the BS to the UE by using an upper layer signal (e.g., dci-PayloadSize).

[0166] The SFI information may include time slot formats for multiple service cells, and the service cells may be distinguished based on the service cell ID. For each service cell, a time slot formation combination of SFIs for one or more time slots may be included. For example, when the size of the SFI information bit is 3 bits and consists of the SFI of approximately one service cell, 3 bits of SFI information may configure 8 SFIs or 8 time slot format combinations (hereinafter referred to as SFIs), and the BS may indicate one of the 8 SFIs by using a UE group common DCI (hereinafter, SFI information).

[0167] At least one of the 8 SFIs may be configured as an SFI for a plurality of time slots. For example, Table 4 below shows an example of 3-bit SFI information composed of the time slot format of Table 3. SFI information 5 (time slot format combination ID 0, 1, 2, 3, and 4) is an SFI for one time slot. SFI information 3 (time slot format combination ID 5, 6, and 7) is an SFI for four time slots, which is sequentially applied to the four time slots.

[0168]

Table 4

[0169] Slot format combination ID Time slot format 0 0 1 1 2 2 3 19 4 9 5 0 0 0 0 6 1 1 1 1 7 2 2 2 2

[0170] The UE receives configuration information about the PDCCH for which the SFI information is to be detected by using an upper layer signal, and detects the SFI according to the configuration. For example, the UE is configured by the upper layer signal with respect to the search space and CORESET from which the SFI information is to be detected, with respect to the RNTI information used for CRC scrambling on the DCI for transmitting the SFI information, or with respect to the period and offset information of the search space.

[0171] Figure 4 Slot Format Indicator (SFI) information in an NR system according to an embodiment is shown.

[0172] refer to Figure 4 , the PDCCH regions 420, 422 and 424 from which the UE needs to detect SFI information and the time period of the PDCCH regions 420, 422 and 424 are 2 time slots. In other words, based on the PDCCH regions 420, 422 and 424 and the time period, the UE can detect the DCI scrambled by the SFI identifier (hereinafter, SFI-RNTI) from the PDCCH regions 420, 422 and 424 in time slot n 400, time slot n+2 402 and time slot n+4 404. The UE can obtain the SFI about two time slots from the detected DCI. In this regard, the detected DCI may include SFI information about two or more time slots, and how many time slots are indicated by the SFI to be included may be configured by an upper layer signal. Configuration information about how many time slots are indicated by the included SFI may be included in the same upper layer signal that configures the SFI information. For example, Figure 4 A case is shown where the UE obtains two SFI information 410 and 411 about slot n 400 and slot n+1 401 from the PDCCH region 420 of slot n 400. In this regard, the plurality of SFI information 410, 411, 412, 413, and 414 refer to the format shown in Table 3.

[0173] When SFI information is transmitted in an unlicensed band, particularly when the SFI information includes SFIs for a plurality of time slots, the BS may be unable to determine SFI information for at least one time slot when failing to access a channel in the unlicensed band.

[0174] In other words, refer to Figure 4, when the BS performs a channel access procedure on the unlicensed band before slot n 400 and determines that the unlicensed band is an idle channel according to the result of the channel access procedure, and then occupies and uses the channel from slot n 400 to slot n+4 404, the BS cannot estimate the channel access procedure result about the unlicensed band in slot n+5 405. Therefore, the BS cannot determine the SFI of slot n+5 405. In other words, when the BS transmits two SFI information 414 and 415 about slot n+4 404 and slot n+5 405 in the PDCCH region 424, a method is needed to determine the SFI information of slot n+5 405.

[0175] Therefore, in the present disclosure, there is a need for a method of determining SFI information and a method of transmitting and receiving the determined SFI information, the method being performed by a BS and a UE configured to determine a structure of a time slot by using SFI in an unlicensed band.

[0176] A method and apparatus may be used to determine SFI information. In addition, it is assumed that the BS sends the SFI information to the UE by using DCI, and the UE receives and uses the SFI information, but the UE may also send the SFI information to the BS by using uplink control information (UCI), and the BS may receive and use the SFI information. In addition, it is assumed that the BS and the UE operate in an unlicensed band, but the BS and the UE may also operate in a licensed band or a shared spectrum.

[0177] Furthermore, it is assumed that the SFI information is transmitted to a designated UE or a designated group of UEs via the PDCCH, but the SFI information (or UL-DL-configuration information) transmitted to the UE by using a higher layer signal may also be used.

[0178] In addition, it is assumed that the UE receives a DL data channel (also called PDSCH) from the BS. However, the UE may also send a UL data channel (also called PUSCH) to the BS. In addition, it is assumed that SFIs for multiple time slots are sent at the same time, but it may also be the case that SFIs for one time slot are sent.

[0179] It is assumed that the SFI indicating whether the symbol included in at least one time slot is a UL symbol, a DL symbol, or a flexible symbol can be used interchangeably as SFI or time slot configuration information. In addition, since the unlicensed frequency band channel occupancy time of the BS or UE can be indicated by the SFI, the SFI can also be expressed as channel occupancy time information.

[0180] An embodiment of the present disclosure provides a method for determining the time of sending and receiving channel occupancy time information or SFI information, which is performed by a BS and a UE operating in an unlicensed frequency band. In particular, the BS can access the unlicensed frequency band and send SFI information independently of a PDCCH region preconfigured for receiving SFI by using an upper layer signal, so that the UE can quickly determine the channel occupancy time information or time slot configuration information in the channel occupancy time information of the BS.

[0181] The BS may allow the UE to determine the receiving area and receiving operation of the PDCCH to which the SFI information is to be sent based on the relevant configuration information of the PDCCH related to the PDCCH to which the SFI information is to be sent. The configuration information related to the PDCCH may include at least one of the PDCCH receiving frequency area information, the PDCCH receiving symbol number, the PDCCH receiving period or the offset information.

[0182] Figure 5 is a diagram for describing a period of providing SFI information according to an embodiment.

[0183] refer to Figure 5 , the UE may receive the resource region, time period or offset information of the PDCCH for which the SFI information is to be sent from the BS via an upper layer signal, and may obtain the SFI information by periodically monitoring the resource region of the PDCCH for which the SFI information is to be sent according to the configuration. However, when the BS sends the SFI information via an unlicensed frequency band, the time or time slot at which the SFI information can be sent may be limited depending on whether the BS accesses the channel.

[0184] In other words, Figure 5 As shown, in the case where the PDCCH in which the SFI information is to be transmitted is configured as PDCCH regions 520, 522, and 524, when the BS accesses the unlicensed band at a random symbol of the time slot n 500 and transmits and receives a signal by performing a channel access procedure, the earliest time to transmit the SFI information is the time slot n+2 502. Whether the UE is to perform a preconfigured signal transmission and reception operation may differ according to the SFI information, so it is very effective to transmit the SFI information immediately after the BS accesses the channel. Therefore, a method performed by the BS to access the unlicensed band via a channel access procedure and transmit the SFI information at the earliest time of transmitting a DL control channel is provided.

[0185] refer to Figure 5 , the BS performs a channel access procedure, and when the BS determines that the unlicensed band is an idle channel, the BS accesses the unlicensed band and transmits a DL signal. Here, the BS can send SFI information to the UE in the unlicensed band via the PDCCH at the earliest time of transmitting the DL control channel. In other words, referring to Figure 5, the PDCCH transmission area configured by the UE is time slot n 500, time slot n+2 502 and time slot n+4 504, but after the BS accesses the channel, the BS needs a method to send the DL control channel at the earliest time (see Figure 5 A method for sending SFI information at reference number 530 in the figure.

[0186] In other words, the UE can be configured by an upper layer signal in every X time slot or every Y symbols relative to the PDCCH reception period of the PDCCH for sending SFI information. In this regard, X or Y can be predefined between the BS and the UE. In addition, the UE can be configured for multiple reception time periods of the PDCCH for sending SFI information, and the intervals can be applied differently depending on whether the BS occupies the channel. For example, X1 or Y1 can be a PDCCH reception time period within the channel occupancy time of the BS, and X2 or Y2 can be a PDCCH reception time period within a time other than the channel occupancy time of the BS. Describing PDCCH reception in a time slot period, X1 can be a value of 526, whose time period has multiple time slots, and X2 can be a value, whose time period is every time slot or one or more symbols. In this regard, the X1 period can be applied relative to the time slot from which the UE obtains the SFI information. In other words, as Figure 5 As shown, a UE receiving a PDCCH in time slot n+1 501 can search for and obtain SFI information in time slot n+3 503 after an X1 period (value 526) relative to time slot n+1 501. In other words, the UE can be configured separately with respect to a first reception period of a first resource region of a PDCCH through which SFI information is transmitted or a time slot in which SFI information is not received in a time other than a channel occupancy time of a BS, or to a second reception period of a second resource region of a PDCCH through which SFI information is transmitted in a channel occupancy time of a BS. In this regard, the UE is configured to determine a second resource region of a PDCCH through which SFI information is transmitted in a channel occupancy time of a BS based on a start time point or a start time slot of a channel occupancy time of a BS, so that the SFI information can be transmitted quickly.

[0187] In addition to the method of configuring and determining the period or transmission resource region of the PDCCH through which the SFI information is transmitted, the present disclosure can also be applied to the method of configuring and determining the period or transmission resource region for which the DCI PDCCH other than the SFI information is transmitted. For example, the method can also be applied to the PDCCH, CORESET, common search space, or UE-specific search space in which the DCI for configuring DL data reception or UL data reception is transmitted.

[0188] An embodiment of the present disclosure provides a method for determining the time of sending and receiving channel occupancy time information or SFI information, which is performed by a BS and a UE operating in an unlicensed frequency band. In particular, according to an embodiment, a BS that has accessed an unlicensed frequency band is allowed to additionally send SFI information to a PDCCH region pre-configured for receiving SFI by using an upper layer signal, so that the UE can quickly determine the channel occupancy time information of the BS or the time slot configuration information in the channel occupancy time information.

[0189] The BS can allow the UE to determine the reception area and reception operation of the PDCCH to which the SFI information is to be sent through the PDCCH-related configuration information about the PDCCH to which the SFI information is to be sent. The PDCCH-related configuration information may include at least one of the PDCCH reception frequency area information, the PDCCH reception symbol number, the PDCCH reception period or the offset information.

[0190] Figure 6 is a diagram for describing a period of providing SFI information according to an embodiment.

[0191] refer to Figure 6 , the UE may receive the time and frequency resource region of the PDCCH, the period of the PDCCH, or the offset information of the PDCCH for which the SFI information is to be sent from the BS via an upper layer signal, and may obtain the SFI information by periodically monitoring the PDCCH region for which the SFI information is to be sent according to the configuration. However, when the BS sends the SFI information via an unlicensed frequency band, the time or time slot at which the SFI information can be sent may be limited depending on whether the BS accesses the channel.

[0192] In other words, Figure 6 As shown, in the case where the PDCCH in which the SFI information is to be transmitted is configured as PDCCH regions 620, 622, and 625, when the BS accesses the unlicensed band at a random symbol of the time slot n 600 by performing a channel access procedure, and the time of transmitting and receiving a signal, the earliest time for transmitting the SFI information is the time slot n+2 602. Because whether the UE performs a preconfigured signal transmission and reception operation may differ according to the SFI, it is effective to transmit the SFI information immediately after the BS accesses the channel. Therefore, a method performed by the BS to access the unlicensed band via a channel access procedure and transmit the SFI information at the earliest time of transmitting a DL control channel is provided.

[0193] refer to Figure 6, the BS performs a channel access procedure, and when the BS determines that the unlicensed band is an idle channel, the BS accesses the unlicensed band and transmits a DL signal. Here, the BS can send the SFI information to the UE in the unlicensed band via the PDCCH at the earliest time of transmitting the DL control channel. In other words, referring to Figure 6 , the PDCCH transmission area configured by the UE is time slot n 600, time slot n+2 602 and time slot n+4 604, but after the BS accesses the channel, the BS needs a way to send the DL control channel at the earliest time (see Figure 6 A method for sending SFI information (as shown in FIG. 630 or 640).

[0194] In other words, the BS transmits the SFI information on symbols or time slots in addition to the preconfigured PDCCH symbols or preconfigured PDCCH time slots for transmitting the SFI information. That is, after the BS performs the channel access procedure, the BS may transmit the SFI information on the earliest symbol or earliest time slot in which the PDCCH can be transmitted. In this regard, the time and frequency resources of the PDCCH for which the SFI information is additionally transmitted may be equal to the configuration of the time and frequency resources of the PDCCH.

[0195] Therefore, the UE can be configured for multiple reception periods of the PDCCH for sending SFI information, and the intervals can be applied differently depending on whether the BS occupies the channel. For example, X1 or Y1 can be a PDCCH reception period within the channel occupation time of the BS, or a period of the PDCCH configured for sending SFI information therethrough, which is independent of the channel occupation time of the BS. In addition, X2 or Y2 can be a PDCCH reception period of a time other than the channel occupation time of the BS.

[0196] Describing PDCCH reception in a time slot period, X1 can be a value of 626, the period of which has multiple time slots and can be a PDCCH reception period within the channel occupancy time. X2 can be a value whose period is every time slot. In this regard, regardless of the time slot from which the UE obtains SFI information, the preconfigured period can be used as the X1 period. In other words, Figure 6In the embodiment, a UE receiving a PDCCH in a time slot n 600 or a time slot n+1 601 can search and obtain SFI information in preconfigured reception time slots n+2 602 and n+4 604 according to a PDCCH period 626 in which a preconfigured SFI is transmitted. Accordingly, the UE can be separately configured for a first reception period to a first resource region of the PDCCH or a second reception period to a second resource region of the PDCCH, for which SFI information is transmitted at a time or a time slot in which SFI information is not received except for a channel occupancy time of the BS, and for which SFI information is transmitted in a channel occupancy time of the BS in a second reception period of the second resource region of the PDCCH. In this regard, the UE is configured to determine a second resource region of the PDCCH for which SFI information is transmitted in a channel occupancy time of the BS based on a starting time point or a starting time slot of a channel occupancy time of the BS, so that the SFI information can be transmitted quickly.

[0197] Although the present disclosure has been described with respect to a method for configuring and determining a period or a transmission resource region of a PDCCH via which SFI information is transmitted, the method may also be applied to configuring and determining a period or a transmission resource region of a PDCCH for which DCI other than SFI information is transmitted. For example, the method may also be applied to a PDCCH, a CORESET, a common search space, or a UE-specific search space in which a DCI for configuring DL data reception or UL data reception is transmitted.

[0198] An embodiment of the present disclosure provides a method for configuring channel occupancy time information or SFI information, which is performed by a BS from among a BS and a UE operating in an unlicensed frequency band. In the unlicensed frequency band, the BS can perform a channel access process, and when the BS accesses the channel according to the result of the channel access process, the BS can schedule the UE's DL signal transmission and UL signal transmission in the MCOT. In this regard, the BS can send the time slot format of the time slot in the MCOT to the UE via the PDCCH, that is, the BS can send an SFI indicating whether each symbol constituting the time slot is a DL symbol, a UL symbol, or a flexible symbol. In this regard, the SFI information (or SFI-DCI) sent via the PDCCH may include SFIs for multiple time slots, and the number of SFIs to be sent in the SFI information may be configured based on the MCOT and the subcarrier spacing (SCS).

[0199] For example, when MCOT is 4 ms and SCS is 15 kHz, a maximum of 4 time slots may be included in MCOT. Therefore, SFI information transmitted via PDCCH in a cell or BWP in which MCOT is configured as 4 ms and SCS is configured as 15 kHz may include SFI information about at least 4 time slots. In this regard, a UE that receives the SFI information may determine a channel occupancy time (COT) and a time slot format of a BS based on the SFI information.

[0200] However, because the BS can transmit a signal by accessing the unlicensed band at a random symbol in the slot, that is, when the BS can transmit a DL signal at the first symbol and the next symbol of the slot in the unlicensed band, one slot may require an additional SFI.

[0201] That is, it may be necessary to include SFI information having a maximum of 5 time slots. Figure 5 , when the COT 550 of the BS is 4 ms and the BS transmits a signal at 15 kHz of the SCS, when the BS is able to transmit a DL signal on a symbol after the first symbol in the slot n 500 in the unlicensed band, SFI information including SFI about 5 slots from the slot n 500 to the slot n+4 504 is required. In other words, the number of slots (N) indicated by the SFI of the SFI information can be configured to be greater than the number of slots included in the MCOT. This can be determined by using the following formula (2) or formula (3).

[0202] N=N_slot per MCOT_p_u+1or N=max(N_slot per MCOT_p_u+1),p=1,2,3,4...(2)

[0203] N_slot per MCOT_p_u represents the number of time slots included in the MCOT with respect to the subcarrier spacing u and the priority level p. When the signal to be transmitted and received includes signals corresponding to a plurality of priority levels, or when the priority level can be dynamically selected, N_slot per MCOT_p_u may be the maximum number of time slots included in the MCOT with respect to the plurality of priorities, or may be the number of time slots included in the MCOT with respect to the highest priority level p (or p with the lowest priority level). In other words, N_slot per MCOT_p represents the number of time slots included in MCOT_4 with respect to the priority level 4 with the highest priority level or the lowest priority level among the priority levels 1, 2, 3, and 4.

[0204] N=(MCOT_p / ms)*N_slot per subframe_u+1or N=

[0205] max(MCOT_p / ms)*N_slot per subframe_u+1,p=1,2,3,4...(3)

[0206] N_slot per subframe_u represents the number of time slots included in a subframe 1ms relative to the subcarrier spacing u, and MCOT_p represents the MCOT relative to the priority level p. When the signal to be transmitted and received corresponds to at least one of a case where the signal includes a plurality of priority levels or a case where the signal can dynamically select and use a priority level, MCOT_p may be the largest MCOT relative to the plurality of levels p, or may be the MCOT relative to the highest priority level p (or p having the lowest priority level). In other words, for priority level 4 having the highest priority level or the lowest priority level among priority levels 1, 2, 3, and 4, MCOT_p indicates MCOT_4.

[0207] In this regard, MCOT can be a value defined according to the frequency or regional restrictions of the unlicensed band, or can be a value pre-defined between the BS and the UE, and the value of MCOT can be defined differently according to the priority level used in the channel access process for sending signals via the unlicensed band performed by the BS or the UE.

[0208] Because the BS or UE can arbitrarily change the COT of the unlicensed band within the MCOT, the UE can determine the number of time slots whose time slot format is indicated by the SFI information by using the MCOT. The UE can fix the size or number of bits of the SFI information by fixing the number of time slots whose time slot format is indicated by the SFI information using the MCOT. Therefore, the size of the SFI information does not change according to the channel access time, priority level, or MCOT of the BS or UE. Therefore, the UE can detect SFI information having one size, thereby minimizing the complexity of the UE.

[0209] In this regard, N or N+1 determined according to formula (2) or (3) may be the maximum number of time slots whose time slot format can be indicated by the SFI information, and the SFI information may include an SFI for indicating the time slot format of time slots, the number of which is less than N or N+1. In other words, at least one piece of information in the SFI information is configured as an SFI for indicating the time slot format of N time slots or N+1 time slots determined according to formula (2) or (3). For example, one piece of information in the SFI information is configured as an SFI for N+1 time slots, and another piece of information in the SFI information is configured as an SFI for N or less time slots.

[0210] For a slot whose slot format is not indicated by the SFI information, the UE may determine that the slot consists of only flexible symbols.

[0211] In this regard, the BS may transmit the slot format of the slots in the MCOT to the UE via the PDCCH, that is, the BS may transmit an SFI indicating whether each symbol constituting the slot is a DL symbol, a UL symbol, or a flexible symbol. In this regard, the SFI information (or SFI-DCI) transmitted via the PDCCH may include SFIs about multiple slots, and the number of SFIs to be transmitted in the SFI information may be configured based on the MCOT and the SCS. When the BS transmits SFI information including SFIs about one or more slots to the UE via the PDCCH, the BS may indicate that the time or symbol before or after the MCOT is a flexible time or a flexible symbol.

[0212] In other words, the BS cannot estimate the result of the channel access procedure performed before the time of accessing the channel of the unlicensed frequency band, or performed in the time or symbol after the MCOT. Therefore, the BS cannot determine the time or symbol used as before or after the MCOT from among the DL symbols and the UL symbols. Therefore, when the BS is required to send SFI information about the time or symbol before or after the MCOT, the BS can indicate the time or symbol as a flexible symbol, and can additionally indicate whether the flexible symbol is a UL symbol or a DL symbol after accessing the channel.

[0213] Figure 7 is a diagram for describing the number of slots whose slot formats are indicated, which number is included in SFI information according to an embodiment.

[0214] refer to Figure 7 The BS can perform a channel access procedure to send and receive signals via an unlicensed band, and when the BS determines that the unlicensed band is idle at a certain time or symbol of time slot n 700, the BS can access the unlicensed band and can send and receive signals during a time period from the start of the channel access time 790 to the MCOT 755 or a specific COT 750 in the MCOT 755.

[0215] Figure 7It is shown that when MCOT 755 is 4 ms, the BS occupies the channel during 3 ms 750 from the start of channel access time 790, and transmits and receives signals. The BS can send SFI information about the time slots within MCOT 755 in PDCCH regions 730 and 735 to the UE via PDCCH, and the SFI information is determined according to the aforementioned method. In other words, SFI 710, 711, 712, 713 and 714 for 5 time slots (N=5) are calculated using the aforementioned formula (2) or (3), and can be sent via PDCCH 730. In this regard, the time slot whose time slot format is represented by the SFI information can be determined based on the PDCCH that transmits the SFI by the method described below.

[0216] refer to Figure 7 , a method will be described based on the PDCCH transmission slot, in which SFIs regarding N slots starting from the slot before X slots are sequentially indicated.

[0217] The BS transmits SFI information about time slots within the MCOT 755 in the PDCCH regions 730 and 735 to the UE via the PDCCH. In this regard, the SFI information may include information about the X time slot ( Figure 7 The SFI of N time slots starting from the time slot before X=1) ( Figure 7 In other words, Figure 7 As shown in the figure, the SFI information sent in the PDCCH region 730 of time slot n+1701 may include SFI about each time slot between time slot n 700 and time slot n+4704, and the SFI information sent in the PDCCH region 735 of time slot n+3 703 may include SFI about each time slot between time slot n+2 702 and time slot n+6 706.

[0218] When the SFI information is transmitted in a time slot after the start time or symbol of the channel access by the BS, a method of indicating the SFI from a time slot before X time slots relative to the time slot in which the SFI information is transmitted may be used to indicate the SFI about the time slot including the start time or symbol of the channel access by the BS to the UE. The UE may perform additional operations including an operation of determining whether to perform a channel quality measurement or a channel quality value compensation operation by using the SFI information.

[0219] In the case where the UE measures the channel quality of symbols from symbols between the first symbol and the sixth symbol of time slot n 700, when the symbols for which the channel quality has been measured are indicated as flexible symbols, based on the SFI information about time slot n 700 indicated by the BS, the UE may not use the information about the measured channel quality.

[0220] The BS may indicate SFI (eg, format X0 710) in SFI information transmitted via PDCCH 730 transmitted in slot n+1 701. The SFI indicates that the first to sixth symbols of slot n 700 are flexible symbols and the seventh to fourteenth symbols of slot n 700 are one or more UL or DL ​​symbols.

[0221] In addition, the BS may indicate an SFI (e.g., format X3 713) indicating that the first symbol to the seventh symbol of the time slot n+3 703 are one or more UL or DL ​​symbols, and the eighth symbol to the fourteenth symbol of the time slot n+3 703 are flexible symbols. Moreover, the BS may indicate an SFI (e.g., format X4 714) indicating that the first symbol to the fourteenth symbol of the time slot n+4 704 are flexible symbols. In this regard, for the time slot n+1 701 and the time slot n+2 702, the BS may indicate an SFI (e.g., formats X2 and X4) indicating that the first symbol to the fourteenth symbol are one or more UL or DL ​​symbols.

[0222] Moreover, the BS may send SFI information about time slot n+2 702 through time slot n+6 706 via the PDCCH 735 sent in time slot n+3 703, and may indicate an SFI (e.g., format X2 722) indicating that the first to fourteenth symbols of time slot n+2 702 are one or more UL or DL ​​symbols, and may indicate an SFI (e.g., format X3 723) indicating that the first to seventh symbols of time slot n+3 703 are one or more UL or DL ​​symbols, and that the eighth to fourteenth symbols of time slot n+3 703 are flexible symbols.

[0223] In this regard, when the SFI regarding a specific time slot is transmitted via different PDCCHs, the SFI indicated via different PDCCHs may be the same. That is, the SFI X2 712 transmitted via the PDCCH 730 and the SFI X2 722 transmitted via the PDCCH 735 must indicate the same value. In other words, when the BS transmits the SFI regarding a specific time slot via the PDCCHs 730 and 735 different from each other within the channel access time 750, the BS may indicate the same SFI (e.g., format X3 713).

[0224] Therefore, the UE does not assume that different SFIs regarding a specific time slot are indicated via different PDCCHs within the channel access time of the BS. However, in the case of a PDCCH sent in different channel access time periods, a specific time slot may be indicated by a different SFI. That is, via a PDCCH sent in a previous channel access time, the BS may indicate an SFI indicating that all symbols are flexible symbols for a specific time slot (e.g., a time slot including symbols before or after the channel access time of the BS), but after the channel access time, when the BS performs a channel access procedure and thus obtains a new COT, the BS may indicate an SFI via a PDCCH sent in the obtained COT, the SFI indicating one or more UL or DL ​​symbols for a specific time slot.

[0225] According to one method, a plurality of pieces of SFI information about N time slots starting from a PDCCH transmission time slot are sequentially indicated. Specifically, the BS transmits SFI information including SFI about time slots within the MCOT 755 in the PDCCH regions 730 and 735 to the UE via the PDCCH. In this regard, the SFI information may sequentially include information about N ( Figure 7 The SFI of N=5) time slots in .

[0226] That is, reference Figure 7 , the SFI information transmitted in the PDCCH region 730 of slot n+1 701 includes SFIs about each slot between slot n+1 701 and slot n+5 705, and the SFI information transmitted in the PDCCH region 735 of slot n+3 703 includes SFIs about corresponding slots between slot n+3 703 and slot n+7 707, so that two pieces of SFI information can be transmitted via the corresponding PDCCH. When a method of sequentially including SFIs from transmission slots in SFI information is used, the UE may determine or assume that the time or symbol before the SFI information is transmitted is composed of all flexible symbols.

[0227] Therefore, the BS may indicate an SFI in the SFI information transmitted via the PDCCH 730 transmitted in the slot n+1 701, the SFI (e.g., formats X1 and X2) indicating that the first symbol to the fourteenth symbol of the slot n+1 701 and the slot n+2 702 are one or more UL or DL ​​symbols. Furthermore, the BS may indicate an SFI (e.g., format X3 713) indicating that the first symbol to the seventh symbol of the slot n+3 703 are one or more UL or DL ​​symbols, and the eighth symbol to the fourteenth symbol of the slot n+3 703 are flexible symbols. Furthermore, the BS may indicate an SFI (e.g., format X4 714 and format X5 715) indicating that the first symbol to the fourteenth symbol of the slot n+4 704 and the slot n+5 705 after the COT 750 are flexible symbols.

[0228] In addition, the BS may send SFI information about time slot n+3 703 to time slot n+7 707 via the PDCCH 735 sent in time slot n+3 703, may indicate an SFI (e.g., format X3 723) indicating that the first to seventh symbols of time slot n+3 703 are one or more UL or DL ​​symbols, the eighth to fourteenth symbols of time slot n+3 703 are flexible symbols, and may indicate an SFI (e.g., formats X4 724, X5 715, X6 726 and X7 727) indicating that the first to fourteenth symbols from time slot n+3 703 to time slot n+7 707 are flexible symbols.

[0229] In this regard, when the SFI about a specific time slot is transmitted via different PDCCHs, the SFI may indicate the same value. That is, SFI X2 712 transmitted via PDCCH 730 and SFI X2 722 transmitted via PDCCH 735 indicate the same value. In other words, when the BS transmits the SFI about a specific time slot via different PDCCHs within the COT, the BS may indicate the same SFI. That is, the UE does not assume that different SFIs about a specific time slot are indicated via different PDCCHs within the channel access time of the BS. However, in the case of SFI information transmitted via PDCCHs transmitted in different channel access time periods, a specific time slot may be indicated by different SFIs. That is, for the PDCCH sent in the previous channel access time, the BS can indicate the SFI indicating that all symbols are flexible symbols for a specific time slot (for example, a time slot including symbols before or after the channel access time of the BS), but after the channel access time, when the BS performs the channel access process and thus obtains a new COT, the BS can indicate the SFI indicating one or more UL or DL ​​symbols for the specific time slot through the PDCCH sent in the obtained COT.

[0230] In this regard, the UE may determine a symbol or slot indicated as flexible and sequential from the end of the slot whose slot format is indicated based on the received SFI information not being included in the COT of the BS. In other words, the UE may determine a symbol or slot indicated as flexible and sequential from the end of the slot whose slot format is indicated. Figure 7 The SFI information received by PDCCH 730 indicates the time slots 704 or symbols sequentially indicated as being flexible starting from the end (time slot 704) among the time slots 700, 701, 702, 703 and 704 of its time slot format, or determines that the time slots 704 and symbols (the eighth symbol to the fourteenth symbol of time slot 703) sequentially indicated as being flexible starting from the end (time slot 704) are symbols or time slots that are not included in the COT of the BS.

[0231] A method for configuring channel occupancy time information or SFI information is provided, which is performed by a BS in a BS and a UE operating in an unlicensed band. When the BS transmits the SFI information more than once via a PDCCH in different time periods within a COT, the BS transmits the same SFI information.

[0232] In the case of transmitting the SFI for a specific time slot, when the SFI about the specific time slot needs to be transmitted via different PDCCHs, the SFI about the specific time slot may be the same. However, since the BS cannot pre-estimate or determine the SFI information about the time slot after the MCOT, the BS may indicate the same SFI when the SFI about the specific time slot is transmitted via different PDCCHs within the COT.

[0233] Therefore, the BS may transmit the offset information together with the SFI information, thereby allowing the UE that has received the SFI information to correctly determine the time slot whose time slot format is indicated by the SFI information. In this regard, the offset information may be time slot unit information or symbol unit information, which is a value indicating the difference between the time slot whose time slot format is indicated by the SFI information and the first time slot whose time slot format is indicated by the SFI information.

[0234] The BS may perform a channel access procedure in an unlicensed band, may access a channel according to a result of the channel access procedure, and may schedule DL signal transmission and UL signal transmission in the MCOT. In this regard, the BS may transmit a slot format of a slot in the MCOT to the UE via the PDCCH, that is, the BS may transmit an SFI indicating whether each symbol constituting the slot is a UL symbol, a DL symbol, or a flexible symbol.

[0235] In this regard, the SFI information (or SFI-DCI) transmitted via the PDCCH may include SFIs regarding a plurality of slots, and the number of SFIs to be transmitted in the SFI information may be configured based on the MCOT and the SCS.

[0236] For example, when the MCOT is 4 ms and the SCS is 15 kHz, a maximum of 4 time slots may be included in the MCOT. Therefore, the SFI information transmitted via the PDCCH in a cell or BWP in which the MCOT is configured as 4 ms and the SCS is configured as 15 kHz may include SFI about at least 4 time slots. In this regard, the UE that receives the SFI information may determine the COT and time slot format of the BS based on the SFI information.

[0237] However, since the BS can transmit a signal by accessing the unlicensed band at a random symbol in the slot, ie, when the BS can transmit a DL signal at the first symbol and the next symbol of the slot in the unlicensed band, one slot may require an additional SFI.

[0238] That is, in the aforementioned example, it may be necessary to include SFI information about SFIs of up to 5 time slots. Figure 8 , when the COT 850 of the BS is 4 ms and the BS transmits a signal at 15 kHz of the SCS, when the BS is able to transmit a DL signal on a symbol after the first symbol in the slot n 800 in the unlicensed band, SFI information is required. The SFI information may include SFIs for 5 slots from slot n 800 to slot n+4 804. In other words, the number of slots (N) of the SFI indicating the SFI information may be configured to be greater than the number of slots included in the MCOT. This can be determined by using the following formula (4) or formula (5).

[0239] N=N_slot per MCOT_p_u+1or N=max(N_slot per MCOT_p_u+1),p=1,2,3,and4....(4)

[0240] N_slot per MCOT_p_u represents the number of time slots included in the MCOT with respect to the subcarrier spacing u and the priority level p. When the signal to be transmitted and received corresponds to at least one of the case where the signal includes a plurality of priority levels or the case where the signal can dynamically select and use a priority level, N_slot per MCOT_p_u may be the largest number among the number of time slots included in the MCOT with respect to the plurality of priority levels, or may be the number of time slots included in the MCOT with respect to the highest priority level p (or p with the lowest priority level). In other words, N_slot per MCOT_p represents the number of time slots included in the MCOT_4 with respect to the highest priority level or the lowest priority level among priority levels 1, 2, 3, and 4.

[0241] N=(MCOT_p / ms)*N_slot per subframe_u+1or N=

[0242] max(MCOT_p / ms)*N_slot per subframe_u+1,p=1,2,3,and 4....(5)

[0243] N_slot per subframe u represents the number of time slots included in the subframe 1ms with respect to the subcarrier spacing u, and MCOT_p represents the MCOT with respect to the priority level p. When the signal to be transmitted and received corresponds to at least one of the case where the signal includes a plurality of priority levels or the case where the signal can dynamically select and use priority levels, MCOT_p may be the largest MCOT with respect to the plurality of levels p, or may be the MCOT with respect to the highest priority level p (or the lowest priority level). In other words, MCOT_p represents the MCOT_4 of the highest priority or the lowest priority among priorities 1, 2, 3, and 4.

[0244] In this regard, MCOT can be a value defined according to the frequency or regional restrictions of the unlicensed band, or can be a value pre-defined between the BS and the UE, and the value of MCOT can be defined differently according to the priority used in the channel access process for sending signals via the unlicensed band performed by the BS or the UE.

[0245] Because the BS or UE can arbitrarily change the COT of the unlicensed band within the MCOT, the BS or UE can determine the number of time slots whose time slot format is indicated by the SFI information by using the MCOT. The UE can fix the size or number of bits of the SFI information by fixing the number of time slots whose time slot format is indicated by the SFI information using the MCOT. By doing so, the size of the SFI information does not change according to the channel access time, priority level, or MCOT of the BS or UE, and the UE can detect SFI information having one size. Therefore, the complexity of the UE can be reduced.

[0246] In this regard, N or N+1 determined according to formula (4) or (5) may be the maximum number of time slots whose time slot format can be indicated by the SFI information, and the SFI information may include an SFI for indicating the time slot format of the time slot, the number of time slots less than N or N+1. In other words, at least one piece of information in the SFI information is configured as an SFI for indicating the time slot format of N time slots or N+1 time slots determined according to formula (4) or (5). For example, one piece of information of the SFI information is configured as an SFI for N+1 time slots, and another piece of information of the SFI information is configured as an SFI for N or less time slots.

[0247] For a slot whose slot format is not indicated by the SFI information, the UE may determine that the slot consists of only flexible symbols.

[0248] In this regard, the BS may send the slot format of the slots in the MCOT to the UE via the PDCCH, that is, the BS may send an SFI indicating whether each symbol constituting the slot is a DL symbol, a UL symbol, or a flexible symbol. In this regard, the SFI information (or SFI-DCI) sent via the PDCCH may include SFIs about multiple slots, and the number of SFIs to be sent in the SFI information may be configured based on the MCOT and the SCS. When the BS sends the SFI information including the SFI about one or more slots to the UE via the PDCCH, the BS may indicate that the time or symbol before or after the MCOT is a flexible time or a flexible symbol.

[0249] In other words, the BS cannot estimate the result of the channel access procedure performed before the time of accessing the channel to the unlicensed band, or performed in the time or symbol after the MCOT, and therefore, the BS cannot determine what to use as the time or symbol before or after the MCOT in the DL symbol and the UL symbol. Therefore, when the BS transmits SFI information multiple times in different time periods within the COT, the BS transmits the same SFI information, and thus may not transmit SFI information about the time or symbol after the MCOT.

[0250] refer to Figure 8, the BS can perform a channel access procedure to send and receive signals via an unlicensed band, and when the BS determines that the unlicensed band is in an idle state at a certain time or symbol of time slot n 800, the BS BS can access the unlicensed band and can send and receive signals during a time period from the start of the channel access time 890 to the MCOT 855 or a specific COT 850 in the MCOT 855.

[0251] Figure 8 It is shown that when MCOT 855 is 4 ms, the BS occupies the channel during 3 ms 850 from the start of the channel access time 890, and transmits and receives signals. The BS can send SFI information about the time slots within MCOT 855 in PDCCH regions 830 and 835 to the UE via PDCCH, and the SFI information is based on the above determination or configuration. In other words, the SFI information of SFI 810, 811, 812, 813 and 814 including 5 time slots (N=5) about the number of time slots (N) is calculated by using the above formula (4) or (5). The SFI information can be sent via PDCCH 830. In this regard, the time slot whose time slot format is indicated by the SFI information can be determined by using the method described below based on the PDCCH and the offset information for which the SFI is sent.

[0252] That is, when offset information (offset Y) with SFI information is sent and the UE receives them, the UE can determine the slot format of the SFI indication starting from the N slots before the slot with offset Y relative to the PDCCH reception slot receiving the SFI information.

[0253] refer to Figure 8 , the BS transmits SFI information about a time slot within the MCOT 855 in the PDCCH regions 830 and 835 to the UE via the PDCCH. In this regard, the SFI information transmitted within the COT of the BS is the same, and the UE can determine the time slot and the SFI corresponding to the time slot based on the SFI information and the offset information received together with the SFI information, wherein the time slot format of the time slot is indicated by the SFI information. The offset information is information about the difference or interval between the time slot in which the PDCCH including the SFI information is received and the first time slot whose time slot format is indicated by the SFI information.

[0254] The same SFI information may be transmitted multiple times via different PDCCH transmission regions 830 and 835 within the COT 850 or MCOT 855 of the BS. In this regard, since the N time slots ( Figure 8The SFI information of the SFI including N=5) in the PDCCH transmission region 835 and the SFI including N time slots sent via the PDCCH transmission region 835 are the same, so the UE can determine the time slot whose time slot format is indicated by the SFI information based on the SFI information and the offset Y received together with the SFI information.

[0255] For example, when the UE receives SFI information about N time slots via the PDCCH transmission region 830, the UE obtains the offset value 840 (Y=1) received together with the SFI information. The UE can determine that the time slot n before the received offset 840 relative to the time slot n+1 in which the PDCCH including the SFI information is received is the first time slot whose time slot format is indicated by the SFI information. That is, the UE can determine that the time slots whose time slot format is indicated by the SFI information are from time slot n 800 to time slot n+4 804.

[0256] In addition, when the UE receives the offset value 845 (Y=3) and the SFI information about N time slots via the PDCCH transmission region 835, the UE can determine that the time slot n before the received offset 845 relative to the time slot n+3 in which the PDCCH including the SFI information is received is the first time slot whose time slot format is indicated by the SFI information. That is, the UE can determine that the time slots whose time slot format is indicated by the SFI information are from time slot n 800 to time slot n+4 804.

[0257] The BS may indicate an SFI (e.g., format X0 810) in the SFI information sent via PDCCH 830 and PDCCH 835 sent in time slot n+1 801 and time slot n+3 803, which SFI indicates that the first symbol to the sixth symbol of the first time slot n 800 are flexible symbols, and the seventh symbol to the fourteenth symbol of time slot n 800 are one or more UL or DL ​​symbols.

[0258] Furthermore, the BS may indicate an SFI (e.g., format X3 813) indicating that the first to seventh symbols of slot n+3 803 are one or more UL or DL ​​symbols, and that the eighth to fourteenth symbols of slot n+3 803 are flexible symbols. Furthermore, the BS may indicate an SFI (e.g., format X4 814) indicating that the first to fourteenth symbols of slot n+4 804 are flexible symbols. In this regard, the BS may indicate an SFI (e.g., formats X2 and X4) indicating that the first to fourteenth symbols of slot n+1 801 and slot n+2 802 are one or more UL or DL ​​symbols. In addition, the SFI information may be configured based on the MCOT independently of the COT of the BS.

[0259] In this regard, the UE may determine, based on the received SFI information, that symbols or slots starting from the end of the slot indicating its slot format are indicated as being flexible and continuous and are not included in the COT of the BS. In other words, the UE may determine that symbols or slots starting from the end of the slot indicating its slot format are indicated as being flexible and continuous and are not included in the COT of the BS. Figure 8 The SFI information received by PDCCH 830 indicates the time slots 804 or symbols sequentially indicated as being flexible starting from the end (time slot 804) among the time slots 800, 801, 802, 803 and 804 of its time slot format, or determines that the time slots 804 and symbols (the eighth symbol to the fourteenth symbol of time slot 803) sequentially indicated as being flexible starting from the end (time slot 804) are symbols or time slots that are not included in the COT of the BS.

[0260] Embodiments of the present disclosure provide a method for configuring channel occupancy time information or SFI information, which is performed by a BS among a BS and a UE operating in an unlicensed frequency band. When the BS sends SFI information more than once via a PDCCH in different time periods within a COT, the BS sends the SFI information and valid time slot information.

[0261] In the case of transmitting the SFI for a specific time slot, when the SFI about the specific time slot needs to be transmitted via different PDCCHs, the SFI about the specific time slot may be the same. However, since the BS cannot pre-estimate or determine the SFI information about the time slot after the MCOT, the BS may indicate the same SFI when the SFI about the specific time slot is transmitted via different PDCCHs within the COT.

[0262] To this end, the BS sends valid time slot information together with the SFI information, thereby allowing the UE that has received the SFI information to correctly determine the time slot whose time slot format is indicated by the SFI information. In this regard, the valid time slot information is information indicating a time slot or symbol used to determine a valid SFI from the time slot whose time slot format is indicated by the received SFI information. The UE can determine a time slot or symbol that is not indicated as a valid time slot as a flexible symbol or a flexible time slot, or as a time slot or symbol whose time slot format is not indicated, from among the time slots whose time slot format is indicated by the received SFI information. In the following, it is assumed that the valid time slot information is time slot unit information, but the valid time slot information may also be symbol unit information.

[0263] The BS may perform a channel access procedure in an unlicensed band, may access a channel according to a result of the channel access procedure, and may schedule DL signal transmission and UL signal transmission in the MCOT. In this regard, the BS may transmit a slot format of a slot in the MCOT to the UE via the PDCCH, that is, the BS may transmit an SFI indicating whether each symbol constituting the slot is a UL symbol, an L symbol, or a flexible symbol.

[0264] In this regard, the SFI information (or SFI-DCI) transmitted via the PDCCH may include SFIs regarding a plurality of slots, and the number of SFIs to be transmitted in the SFI information may be configured based on the MCOT and the SCS.

[0265] For example, when the MCOT is 4 ms and the SCS is 15 kHz, a maximum of 4 time slots may be included in the MCOT. Therefore, the SFI information transmitted via the PDCCH in a cell or BWP in which the MCOT is configured as 4 ms and the SCS is configured as 15 kHz may include SFI about at least 4 time slots. In this regard, the UE that receives the SFI information may determine the COT and time slot format of the BS based on the SFI information.

[0266] However, since the BS can transmit a signal by accessing the unlicensed band at a random symbol in the slot, ie, when the BS can transmit a DL signal at the first symbol and the next symbol of the slot in the unlicensed band, one slot may require an additional SFI.

[0267] That is, in the aforementioned example, it may be necessary to include SFI information about SFIs of a maximum of 5 time slots.

[0268] Fig. 9 is a diagram for describing effective time slot information according to an embodiment.

[0269] refer to Fig. 9 , in the case where the COT 950 of the BS is 4 ms and the BS transmits a signal at 15 kHz of the SCS, when the BS is able to transmit a DL signal on a symbol after the first symbol in the slot n 900 of the unlicensed band, SFI information including SFI about 5 slots from the slot n 900 to the slot n+4 904 is required. In other words, the number of slots (N) indicated by the SFI included in the SFI information may be configured to be greater than the number of slots (at least one slot) included in the MCOT. This can be determined by using the following formula (6) or formula (7).

[0270] N=N_slot per MCOT_p_u+1or N=max(N_slot per MCOT_p_u+1),p=1,2,3,and4...(6)

[0271] N_slot per MCOT_p_u represents the number of time slots included in the MCOT with respect to the subcarrier spacing u and the priority level p. When the signal to be transmitted and received corresponds to at least one of the case where the signal includes a plurality of priority levels or the case where the signal can dynamically select and use a priority level, N_slot per MCOT_p_u may be the maximum number of the number of time slots included in the MCOT with respect to the plurality of priority levels, or may be the number of time slots included in the MCOT with respect to the highest priority level p (or p with the lowest priority level p). In other words, N_slot per MCOT_p represents the number of time slots included in the MCOT_4 with respect to the priority level 4, which may be the highest or lowest priority level among the priorities 1, 2, 3, and 4.

[0272] N=(MCOT_p / ms)*N_slot per subframe_u+1or N=

[0273] max(MCOT_p / ms)*N_slot per subframe_u+1,p=1,2,3,and 4...(7)

[0274] N_slot per subframe u indicates the number of time slots included in the subframe 1ms with respect to the subcarrier spacing u, and MCOT_p indicates the MCOT with respect to the priority level p. When the signal to be transmitted and received corresponds to at least one of the case where the signal includes a plurality of priority levels or the case where the signal can dynamically select and use a priority level, MCOT_p may be the largest MCOT with respect to the plurality of levels p, or may be the MCOT with respect to the highest priority level p (or p with the lowest priority level p). In other words, MCOT_p indicates MCOT_4 with respect to priority level 4, and priority level 4 may be the highest or lowest priority level among priority levels 1, 2, 3, and 4.

[0275] In this regard, MCOT can be a value defined according to the frequency or regional restrictions of the unlicensed band, or can be a value pre-defined between the BS and the UE, and the value of MCOT can be defined differently according to the priority level used in the channel access process performed by the BS or the UE to send signals via the unlicensed band.

[0276] Since the BS or UE can arbitrarily change the COT of the unlicensed band within the MCOT, the BS or UE can determine the number of time slots whose time slot format is indicated by the SFI information by using the MCOT. The UE can fix the size or the number of bits of the SFI information by fixing the number of time slots whose time slot format is indicated by the SFI information by using the MCOT, and by doing so, the size of the SFI information is not changed according to the channel access time, priority level or MCOT of the BS or UE, so that the UE can detect the SFI information having one size, thereby minimizing the complexity of the UE.

[0277] In this regard, N or N+1 determined according to formula (6) or (7) may be the maximum number of time slots whose time slot format may be indicated by the SFI information, and the SFI information may include an SFI for indicating the time slot format of time slots, the number of which is less than N or N+1. In other words, at least one piece of SFI information is configured as an SFI for indicating the time slot format of N time slots or N+1 time slots determined according to formula (6) or (7). For example, one piece of SFI information is configured as an SFI for N+1 time slots, and another piece of SFI information is configured as an SFI for N or less time slots.

[0278] For a slot whose slot format is not indicated by the SFI information, the UE may determine that the slot consists of only flexible symbols.

[0279] In this regard, the BS may send the slot format of the slots in the MCOT to the UE via the PDCCH, that is, the BS may send an SFI indicating whether each symbol constituting the slot is a DL symbol, a UL symbol, or a flexible symbol. In this regard, the SFI information (or SFI-DCI) sent via the PDCCH may include SFIs about multiple slots, and the number of SFIs to be sent in the SFI information may be configured based on the MCOT and the SCS. When the BS sends the SFI information including the SFI about one or more slots to the UE via the PDCCH, the BS may indicate that the time or symbol before or after the MCOT is a flexible time or a flexible symbol.

[0280] In other words, the BS cannot estimate the result of the channel access procedure performed before the access time for the channel of the unlicensed band or performed at the time or symbol after the MCOT, and therefore, the BS cannot determine what to use as the time or symbol before or after the MCOT in the DL symbol and the UL symbol. Therefore, when the BS transmits SFI information multiple times in different time periods within the COT, the BS transmits the same SFI information, and thus may not transmit SFI information about the time or symbol after the MCOT.

[0281] refer to Fig. 9, the BS can perform a channel access procedure to send and receive signals via an unlicensed band, and when the BS determines that the unlicensed band is in an idle state at a certain time or symbol of time slot n 900, the BS can access the unlicensed band and can send and receive signals during a time period from the start of the channel access time 990 to the MCOT 955 or a specific COT 950 in the MCOT 955.

[0282] Fig. 9 It is shown that when MCOT 955 is 4 ms, the BS occupies the channel during 3 ms 950 from the start of channel access time 990, and transmits and receives signals. The BS may transmit SFI information about time slots within MCOT 955 in PDCCH regions 930 and 935 to the UE via PDCCH, the SFI information being determined or configured as previously described. In other words, for the number of time slots (N) calculated by using formula (6) or (7), SFI information including SFI 910, 911, 912, 913, and 914 about 5 time slots (N=5) may be transmitted via PDCCH 930. In this regard, the time slot whose time slot format is indicated by the SFI information may be determined based on PDCCH and valid time slot information 940 for which SFI is transmitted.

[0283] That is, when the information about the valid time slot Z and the SFI information are transmitted and the UE receives them, the UE can determine that the SFI for the valid time slot Z in sequence in the SFI information is valid, and can transmit and receive signals based on the time slot format determined to be valid. The UE can determine the time slot or symbol that is not indicated as a valid time slot by the received SFI information as a flexible symbol or a flexible time slot or a time slot or symbol for which the time slot format is not indicated.

[0284] refer to Fig. 9 , the BS transmits SFI information including SFI about a time slot within the MCOT 955 in the PDCCH regions 930 and 935 to the UE via the PDCCH. In this regard, the SFI information transmitted within the COT of the BS is the same, and the UE can correctly determine a time slot and an SFI corresponding to the time slot based on the SFI information and valid time slot information received together with the SFI information, wherein the time slot format of the time slot is indicated by the SFI information.

[0285] The UE may sequentially determine that the SFI of the time slots regarding the valid time slot Z in the received SFI information is valid, and transmit and receive signals according to the SFI. In addition, the BS may include information indicating the valid time slots, and may provide the valid time slot information.

[0286] The SFI information may be transmitted via different PDCCH transmission regions 930 and 935 within the COT 950 or MCOT 955 of the BS. In this regard, when transmitting the SFI information including information about N time slots ( Fig. 9 In the case where SFI information of an SFI including N time slots is transmitted via the PDCCH transmission region 935, when the SFI information includes information about symbols or time slots after the MCOT 955 of the BS, the UE can correctly determine the time slot format by using the SFI information and the information about the valid time slot Z received together with the SFI information.

[0287] For example, when the UE receives SFI information about N time slots 900, 901, 902, 903, and 904 via the PDCCH transmission region 930, the UE obtains a value (Z=4) of valid time slot information 940 received together with the SFI information. The UE can sequentially determine that the SFI for Z time slots 900, 901, 902, and 903 in the SFI for the N time slots is valid. Similarly, when the UE receives a value (Z=2) of valid time slot information 945 and the SFI information for N time slots 902, 903, 904, 905, and 906 via the PDCCH transmission region 935, the UE can sequentially determine that the Z time slots 902 and 903 in the SFI for the N time slots are valid.

[0288] The BS may indicate an SFI (e.g., format X0 910) in the SFI information sent via PDCCH 930 and in PDCCH 935 sent in slot n+1 901 and slot n+3 903, wherein the SFI indicates that the first to sixth symbols of slot n 900 are flexible symbols and that the seventh to fourteenth symbols of slot n 900 are one or more UL or DL ​​symbols.

[0289] Furthermore, the BS may indicate an SFI (e.g., format X3 913) indicating that the first symbol to the seventh symbol of slot n+3 903 are one or more UL or DL ​​symbols, and the eighth symbol to the fourteenth symbol of slot n+3 903 are flexible symbols. Furthermore, the BS may indicate an SFI (e.g., formats X4, X5, and X6) indicating that the first symbol to the fourteenth symbol of slot n+4 904, slot n+5 905, and slot n+6 906 are flexible symbols. Furthermore, the BS may indicate an SFI (e.g., formats X2 and X4) indicating that the first symbol to the fourteenth symbol of slot n+1 901 and slot n+2 902 are one or more UL or DL ​​symbols. According to an embodiment, the SFI information may be configured based on the MCOT independently of the COT of the BS.

[0290] In this regard, the UE may determine that symbols or slots indicated as flexible and sequential from the end in a slot whose slot format is indicated based on the received SFI information are not included in the COT of the BS. In other words, the UE may determine that symbols or slots indicated as flexible and sequential from the end in a slot whose slot format is indicated based on the received SFI information are not included in the COT of the BS. Fig. 9 The SFI information received by PDCCH 930 indicates that among the time slots 900, 901, 902, 903 and 904 of its time slot format, time slots 904 are sequentially indicated as flexible time slots 904 starting from the end (time slot 904) or time slots 904 or symbols (the eighth symbol to the fourteenth symbol of time slot 903) are sequentially indicated as flexible time slots from the end (time slot 904) are symbols or time slots that are not included in the COT of the time slot.

[0291] Fig.10 is a flowchart for describing an operation of a BS according to an embodiment.

[0292] In step 1000, the BS transmits UL and DL signal transmission and reception configuration information including at least one configuration for transmitting and receiving PDCCH, PDSCH and PUSCH to the UE by configuring an upper layer signal. For example, the BS may transmit a PDCCH resource region, a CORESET configuration or a search space configuration for which DL or UL scheduling information is received to the UE by using an upper layer signal. In addition, the BS may transmit information about UL and DL signal transmission and reception configuration to the UE by using an upper layer signal, which includes information about an offset between a PDCCH reception slot and a PDSCH reception slot or a PUSCH transmission slot, PDSCH or PUSCH repetition transmission number information, and information about ungranted PUSCH transmission or SRS transmission.

[0293] In step 1010, the BS further sends configuration information related to SFI by configuring an upper layer signal, and the configuration information includes SFI information or SFI transmission period. In this regard, the upper layer signal for configuring the PDCCH resource area may include multiple period information about the PDCCH, and at least SFI information is sent for the PDCCH. In addition, in step 1010, the BS configures the size or number of bits of the SFI information, and configures the SFI indicated by the configured number of bits. The configuration of SFI may include SFI or a combination of SFIs for multiple time slots. Moreover, the BS may determine and configure the size or number of bits of the SFI information and the combination of SFIs based on the number of time slots included in the MCOT of the BS. Information about the configuration related to the SFI sent to the UE in step 1010 may also be sent in step 1000.

[0294] When the BS attempts to transmit a signal in the unlicensed band, the UE performs a channel access procedure on the unlicensed band in step 1020. In step 1030, the UE determines whether the unlicensed band is in an idle state. When the state of the unlicensed band determined in step 1030 is not in an idle state, the BS continues or resumes the channel access procedure on the unlicensed band in step 1020. When the state of the unlicensed band determined in step 1030 is an idle state, in step 1050, the BS transmits DCI information for scheduling PDSCH reception or PUSCH transmission via the unlicensed band, the DCI information including COT information or SFI information corresponding thereto.

[0295] Fig.11 is a diagram for describing an operation of a UE according to an embodiment.

[0296] In step 1100, the UE receives configuration information about sending and receiving PDCCH, PDSCH and PUSCH from the BS by configuring an upper layer signal, and receives UL and DL signal transmission configuration information including configuration about sending and receiving PDCCH, PDSCH and PUSCH based on the received configuration information. For example, the UE may be configured by a high layer signal from the BS for a PDCCH resource region for which DL or UL scheduling information is received, a CORESET configuration or a search space configuration. In addition, the UE may be configured by an upper layer signal from the BS with respect to UL and DL signal transmission and reception configuration including information about an offset between a PDCCH reception slot and a PDSCH reception slot or a PUSCH transmission slot, PDSCH or PUSCH repetition transmission number information, unauthorized PUSCH transmission or SRS transmission.

[0297] In step 1110 , the UE is additionally configured for the configuration information related to SFI, the configuration information including the SFI information or the SFI transmission period. In this regard, the configuration information related to SFI in step 1110 is included in the configuration information of the upper layer signal transmitted in step 1100 .

[0298] Regarding PUCCH / SRS / PRACH transmission or CSI measurement including PDSCH reception scheduling or PUSCH transmission scheduling, the UE is scheduled or configured by receiving DL or UL scheduling information via the unlicensed band in step 1120. In this regard, step 1120 may be omitted according to an embodiment, and when step 1120 is omitted, the UE may use the upper layer configuration information for DL ​​and UL signal transmission and reception preconfigured in step 1100.

[0299] In step 1130, the UE determines whether SFI information about the time slot is received.

[0300] In step 1140, the UE, which has received or detected the SFI information about the time slot in step 1130, determines the COT of the BS and the SFI within the COT of the BS, and performs transmission and reception of DL and UL signals according to the determined SFI.

[0301] When the UE does not receive or detect SFI information about a slot within the COT of the BS in step 1130 , the UE assumes that symbols constituting the slot in which the SFI information is not received or detected are flexible, and performs DL and UL signal transmission and reception assuming that the symbols are flexible in step 1150 .

[0302] In a system and a node for transmitting and receiving signals in a wireless communication system, the system transmits a COT and an SFI indicating a slot format in the COT. A node receiving the transmission determines the COT and the slot format and determines a DL signal reception resource region or a UL transmission resource region by using information about the determined slot format, thereby making it possible to effectively use an unlicensed frequency band.

[0303] Fig.12 is a flowchart of a method of indicating a COT performed by a BS according to an embodiment.

[0304] In step 1220, the BS transmits PDCCH configuration information.

[0305] The BS may send the PDCCH configuration information to the UE by using an upper layer signal. The upper layer signal may also be referred to as upper layer signaling, and may indicate a method of sending a signal from the BS to the UE by using a DL data channel of the physical layer, or sending a signal from the UE to the BS by using an UL data channel of the physical layer. The upper layer signal may include a signal sent via RRC signaling, PDCP signaling, or a MAC control element, and may include system information (e.g., SIB or MIB).

[0306] The PDCCH configuration information may include at least one of size information about the SFI information, transmission period information about the SFI information, the number of time slots indicated by the SFI information, or SFI information about at least one time slot indicated by the SFI information. In addition, the BS may transmit at least one of size information about the SFI information or transmission period information about the SFI information separately from the PDCCH configuration information.

[0307] In step 1240, the BS performs a channel access procedure to occupy a channel of the unlicensed band.

[0308] The channel access process may include performing an LBT operation. Furthermore, the channel access process may include, but is not limited to, performing a clear channel assessment (CCA) operation, a request to send (RTS) sending operation, and a clear to send (CTS) sending operation.

[0309] The UE may determine the type of channel access procedure based on the target period of channel occupancy and the type of data to be transmitted.

[0310] In step 1260, the BS transmits SFI information about at least one slot within the COT occupied by performing the channel access procedure based on the PDCCH configuration information.

[0311] The SFI information may be determined based on the MCOT of the BS and the COT occupied by performing the channel access process. The MCOT of the BS may refer to the maximum available time for signal transmission, and may refer to the maximum available time that the BS can occupy without LBT operation. The MCOT may be determined based on the priority of the signal or data to be sent by the BS, or may vary according to the configuration of the wireless communication system or national policy. Moreover, the COT of the BS may indicate the time during which the channel is occupied by the BS for communication.

[0312] By performing the channel access process, the SFI information can be sent in the earliest time slot or the earliest symbol within the occupied COT. Based on the earliest time slot or the earliest symbol, the transmission period of the SFI information within the COT can be applied to the reception of the SFI. In other words, although the transmission period of the SFI information is the same within and outside the COT of the BS with respect to the unlicensed frequency band, when the BS occupies the channel, the transmission period of the SFI information can be started again based on the earliest time slot or the earliest symbol within the occupied channel time.

[0313] The BS may transmit the SFI information in the earliest time slot or earliest symbol in the COT occupied by performing the channel access procedure separately from the transmission period of the SFI information. That is, the BS may continuously transmit the SFI information according to the same transmission period, and may additionally transmit the SFI by using the earliest time slot or earliest symbol in the COT.

[0314] The SFI may include information indicating a slot format of a slot, the number of which is determined based on the MCOT of the BS. Furthermore, the number of slots whose slot formats are indicated and included in the SFI may be determined based on the spacing of the carriers. When the UE receives the SFI information, the UE may determine the MCOT of the BS based on the information included in the SFI information, which indicates how many slots have the slot format indicated therein.

[0315] In addition, the SFI may include information indicating a slot format of a slot obtained by adding a predetermined number of slots to the slot, the number of slots being determined based on the COT.

[0316] The SFI information may include information about the type or pattern of symbols included in at least one time slot determined based on the COT. When the UE receives the SFI information, the UE may determine the COT of the BS based on the format (structure) of the time slot contained in the SFI information, the pattern of the format of the time slot, the type of symbols included in the time slot, and the pattern of the symbols. For example, based on a pattern in which at least a predetermined number of flexible symbols are sequentially arranged, the UE may determine that the flexible symbol is outside the COT of the BS.

[0317] In addition, the SFI information may include information indicating a slot format of a slot before or after a predetermined interval relative to a slot in which the SFI information is transmitted. In addition, the SFI information may include information indicating a slot format of a predetermined number of slots starting from a slot in which the SFI information is transmitted.

[0318] The BS may transmit SFI information indicating the format of a time slot prior to a time slot in which the SFI information is transmitted, may transmit SFI information including information indicating the format of time slots starting from a time slot in which the SFI information is transmitted, or may transmit SFI information including information indicating the format of time slots starting from a time slot in which the SFI information is transmitted.

[0319] In addition, the BS may transmit offset information indicating a difference between a time slot in which the SFI information is transmitted and a first time slot whose time slot format is indicated by the SFI information. The offset information may be transmitted together with the PDCCH configuration information, or may be transmitted separately, may be transmitted together with size information about the SFI information or transmission period information about the SFI information, or may be transmitted together with the SFI information.

[0320] The BS may transmit valid slot information indicating which slots have valid slot format information from among the slots whose slot formats are indicated by the SFI information.

[0321] The effective time slot information may be transmitted together with the PDCCH configuration information, or may be transmitted separately, may be transmitted together with the size information about the SFI information or the transmission period information about the SFI information, or may be transmitted together with the SFI information.

[0322] Fig.13 is a flowchart of a method for obtaining COT information performed by a UE according to an embodiment.

[0323] The UE receives the PDCCH based on the PDCCH configuration information from the BS in step 1320. The UE may receive the PDCCH configuration information by using a higher layer signal from the BS, and may receive the PDCCH based on the PDCCH configuration information.

[0324] The PDCCH configuration information may include at least one of size information about the SFI information, transmission period information about the SFI information, the number of time slots indicated by the SFI information, or SFI information about one or more time slots indicated by the SFI information. In addition, the BS may transmit at least one of size information about the SFI information or transmission or reception period information about the SFI information separately from the PDCCH configuration information.

[0325] In step 1340, the UE obtains SFI information in the PDCCH.

[0326] The UE may obtain DCI by detecting the PDCCH region based on the PDCCH configuration information, and may obtain SFI information from the obtained DCI. The SFI information may be determined based on the MCOT of the BS and the COT occupied by performing a channel access procedure.

[0327] By performing a channel access procedure, the UE may receive SFI information from the earliest time slot or earliest symbol within the COT occupied by the BS. The reception period of the SFI information may be applied to the reception of the SFI based on the earliest time slot or earliest symbol within the COT. The UE may have different reception periods or may have the same reception period regardless of the channel occupancy of the BS.

[0328] Even when the UE has the same reception period before and during the channel occupation period of the BS, the BS may additionally transmit the SFI via the earliest slot or the earliest symbol within the COT occupied by performing the channel access procedure.

[0329] In step 1360, the UE determines at least one of the MCOT or the COT of the BS based on the SFI information.

[0330] The UE may determine the MCOT based on the number of slots whose slot format is indicated by the SFI information. For example, when the number of slots whose slot format is indicated by the SFI information is 5, the UE may determine that the MCOT of the BS is 4 ms.

[0331] The UE may determine the COT based on the type or pattern of symbols included in at least one time slot included in the SFI information. For example, when the obtained SFI includes information indicating that both the fourth time slot and the fifth time slot are flexible symbols, the UE may determine that the fourth time slot and the fifth time slot are outside the COT of the BS. When the obtained SFI includes information indicating that symbols of time slots in the reverse direction starting from the last time slot (e.g., the fourth time slot starting from the fifth time slot) are all flexible symbols (e.g., symbols of the fourth time slot and the fifth time slot are all flexible symbols), the UE may determine that the fourth time slot and the fifth time slot are outside the COT of the BS.

[0332] When the UE fails to receive SFI information about a specific slot, the UE may determine that symbols included in the specific slot are all flexible symbols.

[0333] The UE may determine whether to perform at least one of UL transmission or a channel access procedure based on a result of determining the MCOT and the COT of the BS.

[0334] For example, the UE may determine whether to send at least one UL signal of UL control information (e.g., UCI or PUCCH), SRS, PRACH, and PUSCH to the BS based on the MCOT and COT of the BS. Moreover, the UE may determine whether to perform a channel access procedure based on the determined MCOT of the BS and the determined COT.

[0335] The UE may determine the type of channel access procedure based on the determined MCOT of the BS and the determined COT.

[0336] In addition, the UE may also receive the above-mentioned offset information. In addition, the UE may also receive effective time slot information.

[0337] Fig.14 is a block diagram showing an internal structure of a BS according to an embodiment.

[0338] like Fig.14 As shown, the BS of the present disclosure includes a transceiver 1400, a memory 1410, and a processor 1420. The BS may be embodied with more elements than the above elements, or may be embodied with fewer elements than the above elements. Moreover, the processor 1420, the transceiver 1400, and the memory 1410 may be implemented as one chip. Multiple processors may also be provided.

[0339] The receiver and transmitter of the BS may be collectively referred to as a transceiver 1400, and the transceiver 1400 may send and receive signals to / from the UE. The signals sent to or received from the UE may include control information and data. The transceiver 1400 may include: a radio frequency (RF) transmitter configured to up-convert and amplify the frequency of the signal to be sent; and an RF receiver configured to low-noise amplify the received signal and down-convert. In addition, the transceiver 1400 may receive a signal via a wireless channel, may output the signal to the processor 1420, and may send a signal output from the processor 1420 via a wireless channel.

[0340] The processor 1420 may control a series of processes to operate the BS. For example, the transceiver 1400 may receive a data signal including a control signal transmitted from a UE, and the processor 1420 may determine a reception result regarding the control signal and the data signal transmitted from the UE.

[0341] The processor 1420 may perform a channel access procedure on an unlicensed band. For example, the transceiver 1400 may receive a signal transmitted via an unlicensed band, and the processor 1420 may determine whether the unlicensed band is in an idle state by comparing the strength of the received signal with a predetermined value or a threshold value determined as a result value using the bandwidth as a factor.

[0342] The processor 1420 may maintain or change the value of the contention period for the channel access process based on the received data signal reception result of the UE. When it is determined that the unlicensed band is in an idle state, the processor 1420 may control the transceiver 1400 to send a DL signal including SFI information. In this regard, the transceiver 1400 may send a DL signal including information about the UL or DL ​​transmission period within the COT determined by the processor 1420 of the unlicensed band to the UE.

[0343] The transceiver 1400 of the BS may receive a PUSCH transmitted by the UE in a PUSCH transmission resource region determined based on the SFI information and the PDSCH / PUSCH scheduling information.

[0344] The processor 1420 may perform a series of operations for providing a configuration of time slot format information (e.g., SFI information) to the UE, providing time slot format information, and providing a plurality of additional information such as offset information and effective time slot information. That is, the processor 1420 may control other elements of the BS to perform transmission of an upper layer signal, transmission of an SFI, transmission of a DCI, or a channel access procedure.

[0345] The processor 1420 may perform a series of operations to provide information about the time when SFI is provided, information indicating how many SFIs are to be provided, information indicating from which time slot format information is to be provided, and additional information for providing the same SFI information to the same time slot.

[0346] The processor 1420 can control the transceiver 1400 and the memory 1410 to send PDCCH configuration information to the UE by executing the program stored in the memory 1410 to indicate COT, perform a channel access procedure to occupy a channel in an unlicensed frequency band, and provide SFI information about at least one time slot in the COT occupied by performing the channel access procedure. Moreover, the processor 1420 can control other elements of the BS to perform the above-mentioned method of indicating COT.

[0347] The memory 1410 may store programs and data required for the operation of the BS. Furthermore, the memory 1410 may store control signals or data included in a signal obtained by the BS. The memory 1410 may be implemented as a storage medium including a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disk-ROM (CD-ROM), or a digital versatile disk (DVD), or any combination thereof.

[0348] Fig.15 is a block diagram showing an internal structure of a UE according to an embodiment of the present disclosure.

[0349] like Fig.15 As shown, the UE includes a transceiver 1500, a memory 1510, and a processor 1520. The UE may be implemented with more elements than the above elements, or may be implemented with fewer elements than these elements. Moreover, the processor 1520, the transceiver 1500, and the memory 1510 may be implemented as one chip. Multiple processors may also be provided.

[0350] The receiver and transmitter of the UE may be collectively referred to as a transceiver 1500, and the transceiver 1500 may send a signal to a BS or receive a signal from a BS. The signal sent to a BS or received from a BS may include control information and data. The transceiver 1500 may include: an RF transmitter configured to up-convert and amplify the frequency of a signal to be transmitted; and an RF receiver configured to low-noise amplify the received signal and down-convert.

[0351] The transceiver 1500 may receive a signal via a wireless channel, may output a signal to the processor 1520, and may send a signal output from the processor 1520 via a wireless channel. The processor 1520 may control a series of processes so that the UE operates according to an embodiment of the present disclosure. For example, the transceiver 1500 may receive a data signal including a control signal, and the processor 1520 may determine a reception result regarding the data signal. Thereafter, in the case where the UE is required to send a first signal reception result including data reception to the BS at a specific timing, the transceiver 1500 sends the first signal reception result to the BS at a timing determined by the processor 1520.

[0352] When the transceiver 1500 receives information about the UL or DL ​​transmission period in the channel occupancy period of the unlicensed frequency band from the BS, the processor 1520 can reconfigure or change the UE's DL control channel transmission time or period, or the UE can reconfigure or change the time domain allocation information of the scheduled UL data channel, so that the transceiver 1500 of the UE can receive the DL control channel sent by the BS.

[0353] The transceiver 1500 of the UE may receive a reception result regarding UL data transmitted by the transceiver 1500 from the BS, and the processor 1520 may maintain or change the size of a contention period used in a channel access procedure for signal transmission in an unlicensed band according to the received reception result.

[0354] The transceiver 1500 of the UE may receive the SFI information transmitted by the BS, and the processor 1520 may reconfigure or change the time domain allocation information of the scheduled UL data channel based on the received SFI information.

[0355] The processor 1520 may perform a series of operations for receiving a configuration of time slot format information from the BS, such as SFI information, time slot format information, and a plurality of additional information such as offset information and effective time slot information. In addition, the processor 1520 may obtain the time slot format information based on the received information. That is, the processor 1520 may control other elements of the UE to perform reception of an upper layer signal, reception of an SFI, reception of a DCI, or a channel access process.

[0356] Moreover, the processor 1520 may perform a series of operations to obtain information about the time when the SFI is provided, information indicating how many SFIs are to be provided, information indicating from which time slot format information is to be provided, and additional information for providing the same SFI information to the same time slot. In addition, the processor 1520 may determine the time slot format of each time slot based on the obtained information, and communicate according to the determined time slot format.

[0357] The processor 1520 can control the transceiver 1500 and the memory 1510 to receive the PDCCH from the BS based on the PDCCH configuration information by executing the program stored in the memory 1510, so as to obtain COT information, obtain the SFI information in the received PDCCH, and determine at least one of the MCOT or COT of the BS based on the SFI information. In addition, the processor 1520 can control other elements of the UE to perform the above-mentioned method of obtaining COT information.

[0358] The memory 1510 may store programs and data required for the operation of the UE. In addition, the memory 1510 may store control signals or data included in a signal obtained by the UE. The memory 1510 may be implemented as a storage medium including ROM, RAM, hard disk, CD-ROM or DVD or any combination thereof.

[0359] The method according to the embodiments of the present disclosure described in the claims or the present disclosure may be implemented in hardware, software, or a combination of hardware and software.

[0360] When the method is implemented in software, a computer-readable recording medium having one or more programs (software modules) recorded thereon may be provided. The one or more programs recorded on the computer-readable recording medium are configured to be executable by one or more processors in the device. The one or more programs include instructions for executing the method of the embodiment of the present disclosure described in the claims or detailed description.

[0361] The program (e.g., software module or software) may be stored in RAM, non-volatile memory including flash memory, ROM, electrically erasable programmable read-only memory (EEPROM), magnetic disk storage device, CD-ROM, DVD, another type of optical storage device, or magnetic tape cassette. Alternatively, the program may be stored in a storage system that includes a combination of some or all of the above storage devices. In addition, a plurality of such storage devices may be provided.

[0362] The program may also be stored in a connectable storage device that can be accessed via a communication network (e.g., the Internet, an intranet, a local area network (LAN), a wireless LAN (WLAN), or a storage area network (SAN), or a combination thereof). The storage device may be connected to an apparatus according to an embodiment of the present disclosure via an external port. Another storage device on the communication network may also be connected to an apparatus that performs an embodiment of the present disclosure.

[0363] Therefore, services can be effectively provided in the wireless communication system.

[0364] In the foregoing description, according to the embodiments of the present disclosure, the elements are represented in singular or plural form. However, for ease of explanation, the singular or plural form is appropriately selected, and the present disclosure is not limited thereto. In this way, the elements represented in plural form may also be configured as a single element, and the elements represented in singular form may also be configured as multiple elements.

[0365] The embodiments of the present disclosure described with reference to this specification and the accompanying drawings are merely illustrations of specific examples to easily facilitate the description and understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those of ordinary skill in the art that other modifications based on the technical ideas of the present disclosure are feasible. Moreover, the embodiments of the present disclosure may be combined with each other as needed. For example, parts of the methods provided by the present disclosure may be combined with each other to enable the BS and UE to operate. In addition, although the embodiments of the present disclosure are described based on 5G and NR systems, modifications based on the technical scope of the embodiments of the present disclosure may be applied to other similar communication systems, such as LTE, LTE-A, or LTE-A-Pro systems.

[0366] Thus, while the disclosure has been particularly shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.

Claims

1. A method for obtaining channel occupancy time information performed by a user equipment (UE), the method comprising: Receive high-level signaling; detecting downlink control information (DCI) based on at least one of configuration information of a control resource set (CORESET) and configuration information of a search space set included in higher layer signaling; identifying slot format indicator (SFI) information included in the DCI, the slot format indicator (SFI) information indicating a slot format of at least one slot; as well as Based on the SFI information, identify the channel occupancy time of the base station (BS), The SFI information includes information about a time slot format combination of at least one time slot.

2. The method according to claim 1, wherein: The SFI information includes information indicating a slot format of at least one slot corresponding to a channel occupancy time.

3. The method according to claim 1, wherein: The SFI information includes information indicating a slot format of at least one slot starting from a slot in which the DCI including the SFI information is detected.

4. The method according to claim 1, wherein: The high-layer signaling further includes at least one of offset information or period information for monitoring the DCI.

5. The method according to claim 1, wherein: The SFI information includes a slot format combination identifier indicating a slot format combination.

6. A method for indicating channel occupancy time performed by a base station (BS), the method comprising: Sending high-layer signaling to a user equipment (UE); Performing a channel access process to occupy a channel; as well as During the channel occupancy time, based on at least one of configuration information of a control resource set (CORESET) and configuration information of a search space set included in high-layer signaling, transmitting downlink control information (DCI) including slot format indicator (SFI) information indicating a slot format of at least one slot, The SFI information includes information about a time slot format combination of at least one time slot.

7. The method according to claim 6, wherein: The SFI information includes information indicating a slot format of at least one slot corresponding to a channel occupancy time.

8. The method according to claim 6, wherein: The SFI information includes information indicating a slot format of at least one slot starting from a slot in which the DCI including the SFI information is detected.

9. The method according to claim 6, wherein: The higher layer signaling further includes at least one of offset information or period information for monitoring the DCI.

10. The method according to claim 6, wherein: The SFI information includes a slot format combination identifier indicating a slot format combination.

11. A user equipment UE for obtaining channel occupancy time information, the UE comprising: Transceiver; and A processor is coupled to the transceiver and is configured to: Receive high-level signaling, detecting downlink control information (DCI) based on at least one of configuration information of a control resource set (CORESET) and configuration information of a search space set included in higher layer signaling; identifying slot format indicator (SFI) information included in the DCI, the slot format indicator (SFI) information indicating a slot format of at least one slot included in the DCI; as well as Based on the SFI information, identify the channel occupancy time of the base station (BS), The SFI information includes information about a time slot format combination of at least one time slot.

12. The UE according to claim 11, wherein: The SFI information includes information indicating a slot format of at least one slot corresponding to a channel occupancy time.

13. The UE according to claim 11, wherein: The SFI information includes information indicating a slot format of at least one slot starting from a slot in which the DCI including the SFI information is detected.

14. The UE according to claim 11, wherein: The high-layer signaling further includes at least one of offset information or period information for monitoring the DCI.

15. The UE according to claim 11, wherein: The SFI information includes a slot format combination identifier indicating a slot format combination.

16. A base station BS for indicating channel occupancy time, the BS comprising: Transceiver; and A processor is coupled to the transceiver and is configured to: Sending high-layer signaling to a user equipment (UE); Performing a channel access process to occupy a channel; as well as During the channel occupancy time, based on at least one of configuration information of a control resource set (CORESET) and configuration information of a search space set included in high-layer signaling, transmitting downlink control information (DCI) including slot format indicator (SFI) information indicating a slot format of at least one slot, The SFI information includes information about a time slot format combination of at least one time slot.

17. The BS according to claim 16, wherein: The SFI information includes information indicating a slot format of at least one slot corresponding to a channel occupancy time.

18. The BS according to claim 16, wherein: The SFI information includes information indicating a slot format of at least one slot starting from a slot in which the DCI including the SFI information is detected.

19. The BS according to claim 16, wherein: The higher layer signaling further includes at least one of offset information or period information for monitoring the DCI.

20. The BS according to claim 16, wherein: The SFI information includes a slot format combination identifier indicating a slot format combination.

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