Method and apparatus for indicating a time slot format in a wireless communication system

Abstract

The present invention provides a method for a user equipment (UE) to obtain time slot format information. The method includes receiving configuration information about a physical downlink control channel (PDCCH) from a base station (BS); detecting downlink control information (DCI) based on the configuration information; obtaining time slot format indicator (SFI) information and information about channel occupancy time (COT) in the DCI; and determining a time slot or symbol to which the SFI information is to be applied based on the information about the COT.

Description

Technical Field

[0001] The present disclosure generally relates to methods and apparatus for indicating a slot format in a wireless communication system. Background Art

[0002] In order to meet the growing demand for wireless data services since the commercialization of the fourth generation (4G) communication system, efforts have been made to develop the fifth generation (5G) or pre-5G communication system, which may also be referred to as a "beyond 4G network" communication system or a "post-Long Term Evolution (post-LTE)" system. The 5G communication system defined by the Third Generation Partnership Project (3GPP) is called a New Radio (NR) system.

[0003] In order to achieve high data rates, implementation of 5G communication systems in ultra-high frequency millimeter wave (mmWave) bands (e.g., 60 gigahertz (GHz) bands) is being considered. In order to reduce the path loss of radio waves and increase the transmission distance of radio waves in the ultra-high frequency bands of 5G communication systems, various technologies such as beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large antennas are being studied and applied to NR systems.

[0004] In order to improve the system network for 5G communication systems, various technologies have been developed, such as evolved small cells, advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP), and interference cancellation.

[0005] In addition, for 5G communication systems, advanced coding modulation (ACM) technologies such as hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC) have been developed, 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. Internet of Everything (IoE) technology has also 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 IoT, various technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required, and therefore, 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 services can be provided to collect and analyze data obtained from connected objects, thereby creating new value for human life. As existing information technology (IT) and various industries merge and combine with each other, the Internet of Things can be applied to various fields such as smart homes, smart buildings, smart cities, smart cars, connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0007] Various attempts are being made to apply 5G communication systems to IoT networks. For example, 5G communications such as sensor networks, M2M communications, and MTC are being implemented by using technologies including beamforming, MIMO, array antennas, etc. Cloud RAN as an application of the above big data processing technology can be an example of the fusion of 5G communication technology and IoT technology.

[0008] As the above-mentioned wireless communication systems develop and various services can be provided, there is an increasing need to improve a method of indicating a time slot format in the wireless communication system. 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] Beneficial Effects

[0012] Aspects of the present disclosure provide an efficient communication method in a wireless communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0014] Figure 1 A wireless communication system according to an embodiment is shown;

[0015] Figure 2 A BS for use in a wireless communication system according to an embodiment is shown;

[0016] Figure 3A UE for use in a wireless communication system according to an embodiment is shown;

[0017] Figure 4 A communicator in a wireless communication system according to an embodiment is shown;

[0018] Figure 5 shows a radio resource domain in a wireless communication system according to an embodiment;

[0019] Figure 6 A channel access process in an unlicensed frequency band in a wireless communication system according to an embodiment is shown;

[0020] Figure 7 A channel access process in an unlicensed frequency band in a wireless communication system according to an embodiment is shown;

[0021] Figure 8 Scheduling and feedback in a wireless communication system according to an embodiment are shown;

[0022] Fig.9A shows a COT and a time slot format in a wireless communication system according to an embodiment;

[0023] Fig. 9B shows frequency resource allocation types in a wireless communication system according to an embodiment;

[0024] Fig. 9C shows frequency resource allocation types in a wireless communication system according to an embodiment;

[0025] Fig.10 illustrates a type of time resource allocation in a wireless communication system according to an embodiment;

[0026] Fig.11 illustrates a type of time resource allocation in a wireless communication system according to an embodiment;

[0027] Fig.12 is a flowchart illustrating a BS method for determining a time resource allocation region in a wireless communication system according to an embodiment; and

[0028] Fig.13 is a flowchart illustrating a UE method for determining a time resource allocation region in a wireless communication system according to an embodiment. DETAILED DESCRIPTION

[0029] One aspect of the present disclosure is to provide an apparatus and method for determining a channel occupancy time (COT) and / or slot format indicator (SFI) information in the COT in a wireless communication system.

[0030] According to one aspect of the present disclosure, a method for obtaining time slot format information performed by a user equipment (UE) is provided. The method includes: receiving configuration information about a physical downlink control channel (PDCCH) from a base station (BS); based on the configuration information, detecting downlink control information (DCI); obtaining time slot format indicator (SFI) information and information about channel occupancy time (COT) in the DCI; and based on the information about the COT, determining a time slot or symbol to which the SFI information will be applied.

[0031] According to another aspect of the present disclosure, a method for providing time slot format information performed by a base station (BS) is provided. The method includes sending configuration information about a PDCCH to a UE; performing a channel access procedure to occupy a channel in an unlicensed band; and sending a DCI including SFI information to the UE. The DCI includes COT information about a COT occupied due to the channel access procedure, and when a time slot or symbol to which the SFI information is to be applied is determined, the COT information is used.

[0032] According to another aspect of the present disclosure, a UE for obtaining time slot format information is provided. The UE includes a transceiver; and a processor configured to receive configuration information about a PDCCH from a BS, detect a DCI based on the configuration information, obtain SFI information and information about a COT in the DCI, and determine a time slot or symbol to which the SFI information will be applied based on the information about the COT.

[0033] According to another aspect of the present disclosure, a BS for providing time slot format information is provided. The BS includes a transceiver; and a processor configured to send configuration information about a PDCCH to a UE, perform a channel access procedure to occupy a channel in an unlicensed band, and send a DCI including SFI information to the UE. The DCI includes COT information about a COT occupied due to the channel access procedure, and when a time slot or symbol to which the SFI information is to be applied is determined, the COT information is used.

[0034] Implementation

[0035] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the present disclosure, when it is considered that the detailed explanation of the related art may unnecessarily obscure the essence of the present disclosure, the detailed explanation of the related art is omitted. The terms used in the specification are defined in consideration of the functions used in the present disclosure and may be changed according to the intention or common method of the user or operator. Therefore, the definition of the terms is understood based on the entire description of this specification.

[0036] By referring to the following detailed description of the embodiments and drawings of the present disclosure, the advantages and features of the present disclosure and the methods for realizing the same can be more easily understood. However, the present disclosure can be implemented in many different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, these embodiments of the present disclosure are provided to make the present disclosure thorough and complete, and to fully convey the concepts of the present disclosure to those of ordinary skill in the art, and the present disclosure is limited only by the appended claims. Throughout the specification, the same reference numerals may refer to the same elements.

[0037] In the following description, well-known functions or configurations in the art that are not directly related to the present disclosure are not described. By omitting unnecessary detailed description, the concept of the present disclosure can be clearly described.

[0038] In the drawings, some elements may be exaggerated, omitted or roughly shown. In addition, the size of each element does not completely correspond to the actual size of each element.

[0039] Throughout the disclosure, expressions such as "at least one of a, b, or c" may mean only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0040] Examples of the terminal may include UE, a mobile station (MS), a cellular phone, a smart phone, a computer, a multimedia system capable of performing a communication function, and the like.

[0041] In this disclosure, a controller may also be referred to as a processor.

[0042] A layer (or layer arrangement) may also be referred to as an entity.

[0043] Each block of the flowchart illustration and the combination of blocks in the flowchart illustration can be implemented by computer program instructions. The computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for performing the functions specified in the flowchart block or multiple blocks. The computer program instructions can also be stored in a computer-usable or computer-readable memory, which can instruct the computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-usable or computer-readable memory can produce a manufactured product including an instruction device for performing the functions specified in the flowchart block. The computer program instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operating steps to be performed on the computer or other programmable device, thereby generating a computer-implemented process, so that the instructions executed on the computer or other programmable device provide operations for implementing the functions specified in one or more blocks of the flowchart.

[0044] In addition, each block of the flow chart can represent a module, a code segment or a code portion, which includes one or more executable instructions for performing (multiple) specified logical functions. In some alternative embodiments, the functions mentioned in the block may not appear in order. For example, two blocks shown in succession can actually be performed substantially simultaneously, or these blocks can sometimes be performed in reverse order, depending on the functions involved.

[0045] Here, the term "~ unit" can refer to a software or hardware component that performs certain tasks, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, the term "~ unit" is not limited to software or hardware. The "~ unit" can be configured in an addressable storage medium, or configured to operate one or more processors. Therefore, the "~ unit" can include components, such as 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 and variables. The functions provided in the components and "~ units" can be combined into fewer components and "~ units", or further divided into additional components and "~ units". In addition, components and "units" can be implemented as one or more central processing units (CPUs) in an operating device or a secure multimedia card. In an embodiment of the present disclosure, the "~ unit" can include one or more processors.

[0046] Wireless communication systems have evolved from early wireless communication systems that provide voice-centric services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as 3GPP's High Speed ​​Packet Access (HSPA), LTE or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), 3GPP2's High Speed ​​Packet Data (HRPD) and Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.16e, etc. As 5G wireless communication systems, 5G and / or NR wireless communication systems are being established.

[0047] In a 5G communication system, in order to provide various services and support a high data rate, various technologies such as retransmission in units of code block groups (CBGs), uplink signal transmission without uplink scheduling information (e.g., unlicensed uplink transmission), etc., may be introduced. Therefore, in order to perform 5G communication through an unlicensed band, a more efficient channel access procedure is required in consideration of multiple variables.

[0048] In a wireless communication system including a 5G communication system, at least one of services including enhanced mobile broadband (eMBB), massive MTC (mMTC), and ultra-reliable low-latency communication (URLLC) may be provided to the UE. Services may be provided to the same UE in the same time period. The eMBB service may be used for high-speed transmission of high-capacity data, the mMTC service may be used to minimize the power of the terminal and be accessed by multiple terminals, and the URLLC service may be used for high reliability and low latency, but the present disclosure is not limited thereto. These three services may be the main services in a wireless communication system such as an LTE system or a 5G or NR system after an LTE system, but the present disclosure is not limited thereto. The aforementioned services in the 5G system are exemplary, and the services available in the 5G system are not limited to these examples.

[0049] A service that provides URLLC services may be referred to as a URLLC system, and a service that provides eMBB services may be referred to as an eMBB system. Here, the terms "service" and "system" may be used interchangeably or mixed.

[0050] The BS is an entity that allocates resources to the UE and may be at least one of a next generation Node B (gNB), an evolved Node B (eNode B or eNB), a Node B, a wireless point access unit, a BS controller, or a node on a network. Examples of terminals may include UE, MS, cellular phones, smart phones, computers, multimedia systems capable of performing communication functions, and the like.

[0051] A downlink (DL) is a radio transmission path of a signal transmitted from a BS to a UE, and an uplink (UL) is a radio transmission path of a signal transmitted from a UE to a BS.

[0052] Although the embodiments of the present disclosure will be described below using an LTE system or an LTE-A system as an example, and in order to describe the methods and apparatus proposed in the present disclosure, terms such as "physical channel" and "signal" in the legacy LTE or LTE-A system may be used, the embodiments of the present disclosure may be applied to other communication systems with similar technical backgrounds or channel types. For example, 5G mobile communication technology (5G, New Radio, NR) developed after the LTE-A system may be included therein. The present disclosure may also be applied to other communication systems by modification at the discretion of a person of ordinary skill in the art without significantly departing from the scope of the present disclosure.

[0053] As an example of a broadband wireless communication system, a 5G system or a NR system adopts an orthogonal frequency division multiplexing (OFDM) scheme in DL, and adopts OFDM and a single carrier frequency division multiple access (SC-FDMA) scheme or a discrete Fourier transform-spread spectrum-OFDM (DFT-s-OFDM) in UL. The multiple access scheme can distinguish data and control information of each user by allocating and operating time-frequency resources on which data or control information is carried for each user, so that the time-frequency resources do not overlap with each other, that is, so that orthogonality is established.

[0054] The NR system has adopted a hybrid automatic repeat request (HARQ) scheme for retransmitting data at the physical layer when a decoding failure occurs in the initial transmission. The HARQ scheme indicates that when the receiver fails to correctly decode the data, the receiver sends decoding failure indication information (e.g., negative acknowledgment (NACK)) to the transmitter to allow the transmitter to retransmit the data at its physical layer. The receiver can combine the data retransmitted by the transmitter with the data that failed to be decoded previously, thereby improving data reception performance. According to the HARQ scheme, when the receiver correctly decodes the data, the transmitter sends decoding success indication information (e.g., acknowledgment (ACK)) to the transmitter to allow the transmitter to send new data.

[0055] Hereinafter, for the convenience of description, terms indicating signals, terms indicating channels, terms indicating control information, terms indicating network entities, terms indicating device elements, etc. used in the following description are exemplified. Therefore, the present disclosure is not limited to the terms to be described below, and other terms indicating objects having the same technical meanings may be used.

[0056] In the present disclosure, the terms and names defined in some communication standards (eg, 3GPP) will be used to describe various embodiments, but the present disclosure is not limited to these terms and names. The various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0057] Although the embodiments of the present disclosure may be described based on the NR system, the present disclosure is also applicable to various communication systems, including LTE, LTE-A, LTE-A-Pro systems, 5G, etc. Although the present disclosure relates to a system and apparatus for transmitting and receiving signals by using an unlicensed frequency band, the embodiments of the present disclosure may also be applicable to a system operating in a licensed frequency band.

[0058] Higher layer signaling or upper layer signal may refer to a method of transmitting a signal transmitted from a BS to a UE using a DL data channel of a physical layer or a signal transmitted from a UE to a BS using an UL data channel of a physical layer, and may include at least one of radio resource control (RRC) signaling, packet data convergence protocol (PDCP) signaling, or a signal transmission scheme using a medium access control (MAC) control unit (CE). Higher layer signaling or upper layer signal may also include a system information block (SIB), which is system information to be sent to multiple UEs in common, and may also include information other than a master information block (MIB) among multiple pieces of information sent through a physical broadcast channel (PBCH). MIB may also be included in the upper layer signal.

[0059] A method and apparatus for indicating a time slot format in a wireless communication system will be described below. For example, the present disclosure relates to an unlicensed band channel occupancy time and / or a method for transmitting or receiving time slot format indicator information in an unlicensed band channel occupancy time at a node performing UL / DL communication using a wireless communication system (more specifically, an unlicensed band).

[0060] The apparatus and method of the present disclosure can provide a channel access process for sending a UL signal or channel through an unlicensed band performed by a UE, and a method for correctly determining a time resource domain of a UL / DL signal or channel, so that the BS and the UE can further perform communication efficiently.

[0061] Figure 1 A wireless communication system according to an embodiment is shown.

[0062] refer to Figure 1 , the wireless communication system includes a BS 110, a terminal 120, and a terminal 130 using a wireless channel in the wireless communication system. Figure 1 Only one BS 110 is shown, but additional BSs may be present.

[0063] BS 110 provides wireless access to terminals 120 and 130. BS 110 may have a coverage area defined as a preset geographical area based on a range of transmitted signals. BS 110 may also be referred to as an access point (AP), eNB, gNB, 5G node, wireless point, transmission / reception point (TRP) or other terms having the same technical meaning.

[0064] The terminals 120 and 130 may be used by a user and may perform communication with the BS 110 through a wireless channel. At least one of the terminals 120 and 130 may operate without user participation. That is, at least one of the terminals 120 and 130 may be a device that performs MTC and may not be carried by a user. Each of the terminals 120 and 130 may be referred to as a UE, an MS, a subscriber station, a remote terminal, a wireless terminal, a user equipment, or other terms having the same technical meaning.

[0065] The wireless communication environment may include wireless communication in an unlicensed frequency band. BS 110, terminal 120, and terminal 130 may send and receive wireless signals in an unlicensed frequency band (e.g., 5 to 7 GHz and / or 64 to 71 GHz). In an unlicensed frequency band, a cellular communication system and another communication system (e.g., a wireless local area network (WLAN)) may coexist. In order to ensure fairness between the two communication systems, for example, to prevent a channel from being used exclusively by one system, BS 110, terminal 120, and terminal 130 may perform a channel access procedure for the unlicensed frequency band. The channel access procedure for the unlicensed frequency band may include a listen-before-talk (LBT) procedure.

[0066] BS 110, terminal 120 and terminal 130 can send and receive wireless signals in millimeter wave (mmWave) frequency bands (e.g., 28 gigahertz (GHz), 30 GHz, 38 GHz and / or 60 GHz frequency bands). In order to increase channel gain, BS 110, terminal 120 and terminal 130 can perform beamforming, which can include transmit beamforming and receive beamforming. That is, BS 110, terminal 120 and terminal 130 can apply directivity to transmitted signals or received signals. BS 110 and terminals 120 and 130 can select a service beam via a beam search process and a beam management process. After selecting a service beam, communication can be performed using resources that are in a quasi-co-location (QCL) relationship with resources that transmit the service beam.

[0067] Figure 2 A BS used in a wireless communication system according to an embodiment is shown.

[0068] refer to Figure 2 , the BS includes a wireless communicator 210, a backhaul communicator 220, a storage device 230, and a controller 240. However, the elements of the BS are not limited to the foregoing examples. For example, the BS may include more elements than the foregoing elements, or may include fewer elements than the foregoing elements. In addition, the wireless communicator 210, the backhaul communicator 220, the storage device 230, and the controller 240 may be implemented as one chip. The controller 240 may refer to one or more controllers, and each configuration may include at least one processor.

[0069] Wireless communicator 210 performs the function of transmitting or receiving a signal through a wireless channel. For example, wireless communicator 210 performs conversion between a baseband signal and a bit string based on the physical layer specification of the system. For data transmission, wireless communicator 210 can generate complex symbols by encoding and modulating the transmission bit string. For data reception, wireless communicator 210 can reconstruct the reception bit string by demodulating and decoding the baseband signal.

[0070] The wireless communicator 210 up-converts the baseband signal into a radio frequency (RF) band signal, then transmits the RF band signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. The wireless communicator 210 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. The wireless communicator 210 may include multiple transmit and receive paths. In addition, the wireless communicator 210 may include at least one antenna array including multiple antenna elements.

[0071] In terms of hardware, wireless communicator 210 may be configured as a digital unit and an analog unit, and the analog unit may be configured as a plurality of sub-units according to operating power, operating frequency, etc. The digital unit may be configured as a digital signal processor (DSP).

[0072] Wireless communicator 210 may transmit and receive signals as described above. Therefore, all or some parts of wireless communicator 210 may be referred to as a transmitter, a receiver, or a transceiver. Transmission and reception performed through a wireless channel indicate that the aforementioned processing performed by wireless communicator 210 is applied thereto. Wireless communicator 210 may include at least one transceiver.

[0073] The backhaul communicator 220 provides an interface for performing communication with other nodes in the network. That is, the backhaul communicator 220 converts a bit string into a physical signal, which is transmitted from the BS to another node, for example, another access node, another BS, an upper node, a core network, etc., and converts a physical signal into a bit string, which is received from another node.

[0074] The storage device 230 stores basic programs, applications, and data for BS operation, such as configuration information. The storage device 230 may be configured as a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, in response to a request from the controller 240, the storage device 230 provides the stored data. The storage device 230 may include a memory such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disk (CD-ROM), a digital versatile disk (DVD), etc., or a combination of storage media.

[0075] Controller 240 controls the overall operation of the BS. For example, controller 240 sends and receives signals via wireless communicator 210 or backhaul communicator 220. Controller 240 may record data to storage device 230 or read data from storage device 230. Controller 240 may execute the functions of the protocol stack requested by the communication rule. The protocol stack may be included in wireless communicator 210. Controller 240 may include at least one processor.

[0076] Controller 240 may control the BS to perform operations according to various embodiments to be described below. Controller 240 may perform a channel access procedure on an unlicensed frequency band. A transceiver (e.g., wireless communicator 210) may receive a signal transmitted through an unlicensed frequency band, and controller 240 may determine whether the unlicensed frequency band is in an idle state by comparing the strength of the received signal with a threshold value, which is predefined or determined as a value according to a function in which bandwidth is a factor.

[0077] The controller 240 may send a control signal to the UE or receive a control signal from the UE via the transceiver. The controller 240 may send data to the UE or receive data from the UE via the transceiver. Based on the control signal or data signal received from the UE, the controller 240 may determine a transmission result regarding a signal sent to the UE.

[0078] Based on the transmission result, that is, the reception result of the control signal or data signal received by the UE, the controller 240 can maintain or change the value of the contention window for the channel access process (hereinafter, referred to as contention window adjustment). The controller 240 can determine the reference time slot to obtain the transmission result of the contention window adjustment. The controller 240 can determine the data channel for contention window adjustment in the reference time slot. The controller 240 can determine the reference control channel for contention window adjustment in the reference time slot. When it is determined that the unlicensed band is in an idle state, the controller 240 can occupy the channel.

[0079] Figure 3 A UE used in a wireless communication system according to an embodiment is shown.

[0080] refer to Figure 3 , the UE includes a communicator 310, a storage device 320, and a controller 330. However, the elements of the UE are not limited to the foregoing examples. For example, the UE may include more elements than the foregoing elements, or may include fewer elements than the foregoing elements. In addition, the communicator 310, the storage device 320, and the controller 330 may be implemented as one chip. The controller 330 may refer to one or more controllers, and each configuration may include at least one processor.

[0081] The communicator 310 can perform the function of sending and receiving signals through a wireless channel. For example, the communicator 310 performs conversion between a baseband signal and a bit string based on the physical layer specification of the system. For data transmission, the communicator 310 can generate complex symbols by encoding and modulating the transmission bit string. For data reception, the communicator 310 can reconstruct the received bit string by demodulating and decoding the baseband signal. The communicator 310 up-converts the baseband signal to an RF band signal, then transmits the RF band signal through an antenna, and down-converts the RF band signal received through the antenna to a baseband signal. The communicator 310 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0082] The communicator 310 may include multiple transmission and reception paths. The communicator 310 may include at least one antenna array including multiple antenna elements. In terms of hardware, the communicator 310 may be configured as a digital circuit and an analog circuit (e.g., an RF integrated circuit (RFIC)). In this regard, the digital circuit and the analog circuit may be implemented as a package. The communicator 310 may include multiple RF chains. The communicator 310 may perform beamforming.

[0083] The communicator 310 can send and receive signals as described above. Therefore, all or some parts of the communicator 310 can be referred to as a transmitter, a receiver, or a transceiver. In the following description, the transmission and reception performed through the wireless channel indicate that the aforementioned processing performed by the communicator 310 is applicable hereto. The communicator 310 may include at least one transceiver.

[0084] The storage device 320 stores basic programs, applications and data for UE operation, such as configuration information. The storage device 320 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In response to a request from the controller 330, the storage device 320 provides the stored data. The storage device 320 may include a memory, such as a ROM, RAM, a hard disk, a CD-ROM, a DVD, or a combination of storage media.

[0085] The controller 330 controls the overall operation of the UE. For example, the controller 330 sends and receives signals via the communicator 310. The controller 330 records data to the storage device 320 or reads data from the storage device 320. The controller 330 can perform the functions of the protocol stack requested by the communication rules. The controller 330 may include at least one processor or microprocessor, or may be a part of a processor. The controller 330 may include at least one processor. The communicator 310 and / or a part of the controller 330 may be referred to as a communication processor.

[0086] The controller 330 may control the UE to perform operations according to various embodiments to be described below. For example, the controller 330 may receive a DL signal (DL control signal or DL ​​data) sent from the BS via a transceiver (e.g., the communicator 310). The controller 330 may determine the transmission result of the DL signal. The transmission result may include information about feedback such as ACK, NACK, discontinuous transmission (DTX), etc. of the DL signal. The transmission result may be referred to as various terms, including the reception state of the DL signal, the reception result of the DL signal, the decoding result of the DL signal, the HARQ-ACK information of the DL signal, etc. The controller 330 may send a UL signal to the BS via the transceiver as a response signal to the DL signal. The UL signal may explicitly or implicitly include the transmission result of the DL signal.

[0087] The controller 330 may perform a channel access procedure on an unlicensed band. For example, a transceiver (e.g., the communicator 310) may receive a signal transmitted through an unlicensed band, and the controller 330 may determine whether the unlicensed band is in an idle state by comparing the strength of the received signal with a threshold value, which is predefined or determined as a value according to a function in which bandwidth is a factor. The controller 330 may perform an access procedure on an unlicensed band in order to transmit a signal to a BS.

[0088] Figure 4 A communicator in a wireless communication system according to one embodiment is shown.

[0089] refer to Figure 4 , the communicator includes a coding and modulation unit 402 , a digital beamformer 404 , a plurality of transmission paths 406 - 1 to 406 -N, and an analog beamformer 408 .

[0090] The coding and modulation unit 402 performs channel coding. For channel coding, at least one of a low density parity check (LDPC) code, a convolutional code, or a polar code may be used. The coding and modulation unit 402 generates modulation symbols by performing constellation mapping.

[0091] The digital beamformer 404 performs beamforming on a digital signal (e.g., a modulation symbol). For example, the digital beamformer 404 multiplies the modulation symbol by a beamforming weight. The beamforming weight is used to change the amplitude and phase of the signal and may be referred to as a precoding matrix, a precoder, etc. The digital beamformer 404 outputs the modulation symbol digitally beamformed by the plurality of transmission paths 406-1 to 406-N. According to the MIMO transmission technology, the modulation symbol may be multiplexed, or the same modulation symbol may be provided to the plurality of transmission paths 406-1 to 406-N.

[0092] Multiple transmission paths 406-1 to 406-N can convert the digital signal of digital beamforming into an analog signal. Each of the multiple transmission paths 406-1 to 406-N can include an inverse fast Fourier transform (IFFT) operator, a cyclic prefix (CP) inserter, a DAC and an up-converter. The CP inserter is arranged for the OFDM scheme and can be excluded when different physical layer schemes (e.g., FBMC) are applied. That is, multiple transmission paths 406-1 to 406-N provide independent signal processing processes to multiple streams generated by digital beamforming. However, depending on the implementation method, some elements of multiple transmission paths 406-1 to 406-N can be used in common.

[0093] The analog beamformer 408 performs beamforming on the analog signal. The analog beamformer 408 multiplies the analog signal by the beamforming weight. The beamforming weight is used to change the amplitude and phase of the signal. Based on the connection structure between the multiple transmission paths 406-1 to 406-N and the antenna, the analog beamformer 408 can be configured differently. Each of the multiple transmission paths 406-1 to 406-N can be connected to an antenna array, or the multiple transmission paths 406-1 to 406-N can be connected to an antenna array. The multiple transmission paths 406-1 to 406-N can also be adaptively connected to an antenna array or at least two antenna arrays.

[0094] In the 5G system, the frame structure should be flexibly defined considering various services and requirements. For example, services can have different subcarrier spacings respectively according to needs. The current 5G communication system supports multiple subcarrier spacings, and each subcarrier spacing can be determined by using equation (1).

[0095] △f=f 0 *2 m ...(1)

[0096] In equation (1), f 0 represents the default subcarrier spacing of the system, m represents an integer scaling factor, and ∆f represents the subcarrier spacing. 0 =15kHz, a set of subcarrier spacings allowed by the 5G communication system can be configured as one of 3.75kHz, 7.5kHz, 15kHz, 30kHz, 60kHz, 120kHz, 240kHz and 480kHz. A set of allowed subcarrier spacings may vary according to the frequency band. For example, at least one of the subcarrier spacings of 3.75kHz, 7.5kHz, 15kHz, 30kHz and 60kHz may be used in a frequency band less than or equal to 7GHz, and at least one of the subcarrier spacings of 60kHz, 120kHz, 240kHz or greater may be used in a frequency band greater than or equal to 7GHz.

[0097] The length of the OFDM symbol can be changed according to the subcarrier spacing that constitutes the OFDM symbol, because the characteristics of the OFDM symbol, the subcarrier spacing and the length of the OFDM symbol have a reciprocal relationship with each other. For example, when the subcarrier spacing is doubled, the symbol length is halved, and when the subcarrier spacing is halved, the symbol length is doubled.

[0098] Figure 5 A radio resource area in a wireless communication system according to an embodiment is shown.

[0099] refer to Figure 5 , in the radio resource domain as a time-frequency domain structure, its horizontal axis represents the time domain and its vertical axis represents the frequency domain. The minimum transmission unit in the time domain can be an OFDM and / or DFT-s-OFDM symbol, and N symb OFDM and / or DFT-s-OFDM symbols 501 may constitute a slot 502. The OFDM symbol may include a symbol for transmitting or receiving a signal by using an OFDM multiplexing scheme, and the DFT-s-OFDM symbol may include a symbol for transmitting or receiving a signal by using an SC-FDMA multiplexing scheme.

[0100] Although the embodiments of the present disclosure will be described with reference to OFDM symbols, the embodiments are also applicable to DFT-s-OFDM symbols. In addition, although DL signal transmission or reception will be described, the embodiments are also applicable to UL signal transmission or reception.

[0101] When the subcarrier spacing is 15kHz, Figure 5 Different from the example shown in FIG. 5 , one time slot 502 may constitute a subframe 503, and the lengths of the time slot 502 and the subframe 503 may each be 1 ms. The number of time slots constituting one subframe 503 and the length of the time slot 502 may differ depending on the subcarrier spacing. For example, when the subcarrier spacing is 30 kHz, two time slots may constitute one subframe 503, the length of each of the two time slots may be 0.5 ms, and the length of the subframe 503 may be 1 ms. The radio frame 504 may be a time domain interval consisting of 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier, and the carrier bandwidth constituting the resource grid may consist of a total of N subframes. sc BW The subcarriers 505 are composed of 505 subcarriers.

[0102] However, the subcarrier spacing, the number of time slots 502 included in the subframe 503, the length of the time slot 502, and the length of the subframe 503 may be variably applied. For example, in the LTE system, the subcarrier spacing is 15 kHz, two time slots constitute one subframe 503, in which case the length of the time slot 502 may be 0.5 ms, and the length of the subframe 503 may be 1 ms. In the NR system, the subcarrier spacing (μ) may be one of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz, and the number of time slots included in one subframe may be 1, 2, 4, 8, or 16 according to the subcarrier spacing (μ).

[0103] In the time-frequency domain, the default resource unit may be a resource element (RE) 506, and the RE 506 may be represented by an OFDM symbol index and a subcarrier index. A resource block (RB) may include multiple REs. In the LTE system, an RB (or physical RB (PRB)) may be composed of N symb consecutive OFDM symbols and N in the frequency domain SC RB The number of symbols included in an RB can be N. symb =14, the number of subcarriers can be N SC RB =12, or the number of symbols included in one RB may be N symb =7, the number of subcarriers can be N SC RB = 12. The number of RBs (N RB ) can vary depending on the bandwidth of the system transmission band.

[0104] In the NR system, RB 507 can be composed of N SC RB The number of subcarriers can be N. SC RB =12. The frequency domain may include common RBs (CRBs), and PRBs may be defined in a bandwidth part (BWP) in the frequency domain. Different numbers of CRBs and PRBs may be determined according to the subcarrier spacing.

[0105] DL control information may be sent in the first N (multiple) OFDM symbols in a slot. In general, N may be N={1, 2, 3}, and the UE may be configured with the number of symbols in which the DL control information may be sent from the BS via higher layer signaling. Based on the amount of control information to be sent in the current slot, the BS may change the number of symbols in which the DL control information may be sent for each slot, and may send information about the number of symbols to the UE via a separate DL control channel.

[0106] In the NR and / or LTE system, scheduling information for DL ​​data or UL data may be transmitted from the BS to the UE via DCI. The DCI may be defined in various formats, each of which varies depending on whether the DCI includes scheduling information for UL data (UL grant) or scheduling information for DL ​​data (DL grant), whether the DCI corresponds to compact DCI or fallback DCI with small-size control information, whether spatial multiplexing with multiple antennas is applied, and / or whether the DCI corresponds to DCI for power control.

[0107] A DCI format corresponding to scheduling control information (DL grant) for DL ​​data (eg, DCI format 1_0 of NR) may include at least one of the following control information. NR DCI format 1_0 may include scheduling for DL ​​data.

[0108] -DCI format identifier: an identifier used to identify the DCI format

[0109] - Frequency domain resource allocation: indicates the RBs allocated for data transmission

[0110] -Time domain resource allocation: indicates the time slots and symbols allocated for data transmission

[0111] - Virtual RB (VRB) to PRB mapping: Indicates whether the VRB mapping scheme is applied

[0112] - Modulation and Coding Scheme (MCS): Indicates the size of a transport block (TB) as data to be transmitted and the modulation scheme used for data transmission

[0113] - New Data Indicator (NDI): Indicates whether it is a HARQ initial transmission or a retransmission

[0114] - Redundancy Version (RV): Indicates the RV of HARQ

[0115] -HARQ process number: indicates the HARQ process number

[0116] - Physical DL Shared Channel (PDSCH) assignment index (or DL ​​assignment index): indicates the number of PDSCH reception results (e.g., the number of HARQ-ACKs) to be reported from the UE to the BS

[0117] - Transmit Power Control (TPC) command for the physical UL control channel (PUCCH): indicates the TPC command for the PUCCH

[0118] -PUCCH resource indicator: Indicates the PUCCH resource used in HARQ-ACK reporting including the reception result of the PDSCH configured via DCI

[0119] -PUCCH transmission timing indicator (or PDSCH to HARQ feedback timing indicator): indicates information about a slot or symbol in which a PUCCH for reporting HARQ-ACK including a reception result of a PDSCH configured via DCI will be transmitted

[0120] After the channel coding and modulation process, DCI can be sent on PDCCH (or control information) or enhanced PDCCH (EPDCCH) (or enhanced control information). Transmission or reception on PDCCH or EPDCCH can be understood as DCI transmission or reception on PDCCH or EPDCCH, and transmission or reception on PDSCH can be understood as DL data transmission or reception on PDSCH.

[0121] A cyclic redundancy check (CRC) scrambled by a specific radio network temporary identifier (RNTI) or a cell RNTI (C-RNTI) independent of each UE may be added to the DCI, and the DCI of each UE may be channel coded and then configured into an independent PDCCH and transmitted. In the time domain, the PDCCH may be transmitted during the control channel transmission interval. In the frequency domain, the mapping position of the PDCCH may be determined by at least one identifier (ID) of each UE and may be transmitted in the entire system transmission band or in a band configured in the system transmission band. Alternatively, in the frequency domain, the mapping position of the PDCCH may be configured by higher layer signaling.

[0122] DL data may be transmitted on a PDSCH which is a physical channel for DL ​​data transmission. The PDSCH may be transmitted after a control channel transmission interval, and in the frequency domain, scheduling information such as a mapping position of the PDSCH and a modulation scheme for the PDSCH may be determined based on DCI transmitted through the PDCCH.

[0123] Based on the MCS information in the control information configuring the DCI, the BS may notify the UE of the modulation scheme applied to the PDSCH to be transmitted and the size of the data to be transmitted (e.g., the transport block size (TBS)). The MCS may be configured as 5 bits, or may be greater than or less than 5 bits. The TBS corresponds to the size of the TB before the channel coding for error correction is applied to the data (or TB) to be transmitted by the BS. However, the present disclosure is not limited to the above examples, and the size of the MCS and the TB may vary depending on the configuration.

[0124] In the NR system, the modulation scheme supporting UL and DL data transmission may include at least one of quadrature phase shift keying (QPSK), 16-quadrature amplitude modulation (16QAM), 64QAM, or 256QAM, and each modulation order Q mIt can be 2, 4, 6 or 8. For example, for QPSK modulation, 2 bits per symbol can be sent, for 16QAM modulation, 4 bits per symbol can be sent, for 64QAM modulation, 6 bits per symbol can be sent, and for 256QAM modulation, 8 bits per symbol can be sent. Modulation schemes above 256QAM can be used depending on system modifications.

[0125] For a system that performs communication in an unlicensed band, a communication device (BS or UE) attempting to send a signal in the unlicensed band can perform a channel access procedure or LBT on the unlicensed band in which the communication device performs communication before sending the signal, and when it is determined according to the channel access procedure that the unlicensed band is in an idle state, the unlicensed band can be accessed and signal transmission can be performed.

[0126] When it is determined according to the performed channel access procedure that the unlicensed frequency band is not in an idle state, the communication device may not perform signal transmission.

[0127] The channel access procedure in the unlicensed band can be classified by whether the time of starting the channel access procedure of the communication device is fixed (frame-based equipment (FBE)) or variable (load-based equipment (LBE)). In addition to the time of starting the channel access procedure, whether the communication device is FBE or LBE can be determined according to whether the transmission / reception structure of the communication device has a period or not. In this case, the time of starting the channel access procedure is fixed, which means that the channel access procedure of the communication device can be started periodically according to a predefined period or a period declared or configured by the communication device.

[0128] As another example, the time to start the channel access procedure is fixed, which may indicate that the transmit / receive structure of the communication device has a period. In this regard, the time to start the channel access procedure is variable, which indicates that the communication device may send a signal in the unlicensed band at any time. As another example, the time to start the channel access procedure is variable, which may indicate that the transmit / receive structure of the communication device may be determined when necessary without a period.

[0129] Hereinafter, a channel access procedure in which the time of starting the channel access procedure of a communication device is variable, namely LBE (hereinafter referred to as a service-based channel access procedure or an LBE-based channel access procedure) will now be described.

[0130] The channel access process in an unlicensed band may include measuring the strength of a signal received by a communication device in the unlicensed band for a fixed time period or a time period calculated according to a predefined rule (for example, a time calculated using a random value selected by at least the BS or the UE), and determining the idle state of the unlicensed band by comparing the measured signal strength with a predefined threshold or a threshold calculated by a function that determines the magnitude of the received signal strength based on at least one variable of the channel bandwidth, the bandwidth in which the signal is to be sent, and / or the transmission power intensity.

[0131] The communication device can measure the strength of the received signal (e.g., 25us) for the time Xus (the Xus time is immediately before the time point when the signal is to be sent), can determine that the unlicensed band is in an idle state, and can send the configured signal when the measured signal strength is less than a predefined or calculated threshold T (e.g., -72dBm). In this case, after the channel access process, the maximum time period available for continuous signal transmission may be limited by the maximum COT (MCOT) defined for each country, region, or band based on each unlicensed band, or even by the type of communication device (e.g., BS or UE, or master or slave). For example, in Japan's 5GHz unlicensed band, a BS or UE can occupy a channel to send a signal without performing an additional channel access process of up to 4ms for the unlicensed band determined to be in an idle state.

[0132] When a BS or UE attempts to transmit a DL or UL signal in an unlicensed band, a channel access procedure that may be performed by the BS or UE may be identified as at least one of the following types:

[0133] - Type 1: UL / DL signal is transmitted after performing a channel access procedure for a variable period of time

[0134] - Type 2: UL / DL signal is transmitted after performing a channel access procedure for a fixed period of time

[0135] - Type 3: Transmitting DL or UL signals without performing a channel access procedure

[0136] A transmitting device (e.g., BS or UE) attempting to perform signal transmission in an unlicensed band may determine a scheme (or type) of a channel access procedure according to the type of signal to be transmitted. In 3GPP, the LBT procedure as a channel access scheme can be roughly divided into four categories, including: a first category including a scheme that does not perform LBT, a second category including a scheme that performs LBT without random backoff, a third category including a scheme that performs LBT by random backoff in a contention window of a fixed size, and a fourth category including a scheme that performs LBT by random backoff in a contention window of a variable size. The third and fourth categories may be reserved for type 1, the second category may be reserved for type 2, and the first category may be reserved for type 3. In this case, type 2 or the second category that performs a channel access procedure for a fixed time period may be classified into one or more types according to the fixed time period for performing the channel access procedure. For example, type 2 may be classified into a type for performing a channel access procedure for a fixed time period Aμs (e.g., 25μs), and a type for performing a channel access procedure for a fixed time period Bμs (e.g., 16μs).

[0137] The transmitting device may be assumed to be a BS, and thus, the terms transmitting device and BS may be used interchangeably.

[0138] When the BS attempts to transmit a DL signal including a DL data channel in an unlicensed frequency band, the BS may perform a channel access procedure in the scheme of Type 1. Otherwise, when the BS attempts to transmit a DL signal not including a DL data channel in 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 channel access procedure in the scheme of Type 2 and may transmit the DL signal.

[0139] In this case, the scheme of the channel access process can be determined according to the transmission length of the signal to be sent in the unlicensed band or the length of the time period or interval for occupying and using the unlicensed band. Compared with the scheme of type 2, the channel access process in the scheme of type 1 can be performed for a longer time period. Therefore, when the communication device attempts to send a signal in a short time period or a time period less than or equal to the reference time (e.g., X ms or Y symbols), the channel access process can be performed in the scheme of type 2. On the other hand, when the communication device attempts to send a signal in a long time period or a time period greater than or equal to the reference time (e.g., X ms or Y symbols), the channel access process can be performed in the scheme of type 1. That is, according to the use time of the unlicensed band, the channel access process can be performed in one of the different schemes.

[0140] When a transmitting device performs a channel access procedure in a type 1 scheme according to at least one of the above references, the transmitting device attempting to send a signal in an unlicensed band may determine a channel access priority level based on the quality of a service level identifier (e.g., QCI) of the signal to be sent in the unlicensed band, and may perform the channel access procedure by using at least one of the predefined setting values ​​for determining the channel access priority level as shown in Table 1 below.

[0141] Table 1 shows the mapping relationship between the channel access priority level and the QCI. The mapping relationship between the channel access priority level and the QCI in Table 1 is only an example, and thus is not limited thereto.

[0142] For example, QCI 1, 2, and 4 refer to QCI values ​​for services such as conversational voice, conversational video (live stream), and non-conversational video (buffered stream). When a signal for a service that does not match the QCI in Table 1 is to be transmitted in an unlicensed band, the transmitting device may select the QCI closest to the service from the QCIs in Table 1 and may select a corresponding channel access priority level.

[0143]

Table 1

[0144] Channel access priority QCI 1 1，3，5，65，66，69，70 2 2，7 3 4，6，8，9 4 -

[0145] Parameter values ​​of the channel access priority level (e.g., based on the delay duration of the determined channel access priority p, a set of contention window values ​​or sizes (CW_p), the minimum and maximum values ​​of the contention window (CW_min, p and CW_max, p), and the maximum available channel occupancy interval (T_mcot, p)) can be determined as shown in Table 2 below.

[0146] Table 2 shows the parameter values ​​of the channel access priority type of DL.

[0147] Figure 6 A channel access procedure in an unlicensed frequency band in a wireless communication system according to an embodiment is shown.

[0148] refer to Figure 6, a BS attempting to send a DL signal in an unlicensed band may perform a channel access procedure on the unlicensed band for a minimum time period T_f+m_p*T_sl (e.g., delay duration 612). When a BS attempts to perform a channel access procedure with a channel access priority level 3 (p=3), the size of T_f+m_p*T_sl may be configured by using m_p=3, where the size of T_f+m_p*T_sl is the size of T_f+m_p*T_sl of the delay duration required to perform the channel access procedure. In this case, T_f has a value fixed to 16 μs (e.g., duration 610), during which the first T_sl time needs to be in an idle state, and for the remaining time (T_f-T_sl) after T_sl in the T_f time, the BS may not perform the channel access procedure. Even when the BS performs the channel access procedure within the remaining time (T_f-T_sl), the result of the channel access procedure may not be used. That is, T_f-T_sl refers to a time period during which the BS delays performing a channel access procedure.

[0149] When it is determined that the unlicensed band is in an idle state for the entire time m_p*T_sl, N may be N-1 (N=N-1). In this case, N may be selected as any integer value among values ​​between 0 and the value in the contention window (CW_p) at the time when the channel access procedure is to be performed. For channel access priority level 3, the minimum contention window value and the maximum contention window value are 15 and 63, respectively. When the unlicensed band is determined to be in an idle state during the delay duration and the additional duration for which the channel access procedure is to be performed, the BS may transmit a signal in the unlicensed band within time T_mcot,p (8ms).

[0150] Table 2 shows the channel access priority levels for DL. For ease of description, the embodiments of the present disclosure will be described below based on the DL channel access priority levels. The channel access priority levels in Table 2 may also be used for UL, or a separate channel access priority level for UL may be used.

[0151]

Table 2

[0152]

[0153] The initial contention window value CW_p is the minimum value CW_min,p of the contention window. After selecting the value of N, the BS may perform a channel access procedure during an interval T_sl (e.g., a time slot duration 620), and when it is determined through the channel access procedure performed in the interval T_sl that the unlicensed band is in an idle state, the BS may change the value of N to N=N-1, and when N becomes 0 (N=0), the BS may send a signal in the unlicensed band for a maximum T_mcot,p time (e.g., a maximum channel occupancy time 630). When the unlicensed band determined through the channel access procedure is not in an idle state at time T_sl, the BS may perform the channel access procedure again without changing the value of N.

[0154] The amount of the value of the contention window CW_p may be changed or maintained according to the ratio (Z) of NACK among the reception results (ACK / NACK) of DL data transmitted or reported to the BS in the reference subframe, reference time slot or reference TTI by one or more UEs that have received DL data transmitted through a DL data channel in a reference subframe, reference time slot or reference transmission time interval (reference transmission time interval (TTI)). In this case, the reference subframe, reference time slot or reference TTI may be determined as a time point at which the BS initiates a channel access procedure, a time point at which the BS selects a value N to perform a channel access procedure, a first subframe, time slot or TTI of a DL signal transmission interval (or MCOT) involved in the most recent transmission of the BS in an unlicensed band immediately before these two time points, or a start subframe, start time slot or start TTI of a transmission interval.

[0155] The BS may attempt channel access to occupy the unlicensed band. The reference time slot, reference subframe, or reference TTI may be determined as the time point at which the BS initiates the channel access process 670, the time point at which the BS selects a value N to perform the channel access process, or the first time slot (or the starting time slot at which the channel occupation interval starts), the starting subframe, or the starting TTI (640) of the DL signal transmission interval (i.e., MCOT 630) involved in the most recent transmission of the BS in the unlicensed band immediately before the time point. For convenience of description, the reference time slot is referenced in the following description. In detail, the reference time slot may be defined as a time slot including a first time slot or one or more consecutive time slots, wherein the first time slot is a time slot for transmitting a signal among all time slots of the DL signal transmission interval (MCOT 630).

[0156] When the DL signal transmission interval (MCOT 630) starts after the first symbol of the time slot, the time slot where the DL signal transmission starts and the time slots thereafter may be defined as reference time slots. If the ratio of NACK in the DL data reception result transmitted or reported to the BS by one or more UEs receiving the DL data transmitted in the reference time slot through the DL data channel is greater than or equal to Z, the BS may determine the value or size of the content window used in the channel access process 670 of the BS to be a contention window larger than the contention window used in the previous channel access process 602. That is, the BS may increase the size of the contention window used in the previous channel access process 602. The BS may perform the channel access process 670 by selecting the N value 622 within the range defined according to the increased size of the contention window.

[0157] When the BS cannot obtain the reception result of the DL data channel sent in the reference time slot of MCOT 630, for example, when the time interval between the reference time slot and the time point when the BS initiates the channel access procedure 670 corresponds to n time slots or is less than or equal to symbols (i.e., when the BS initiates the channel access procedure before the minimum time period in which the UE can report the reception result of the DL data channel sent in the reference time slot to the BS), the first time slot of the DL signal transmission interval involved in the most recent transmission before the DL signal transmission interval (MCOT 630) can become the reference time slot.

[0158] When the BS cannot receive the reception result of the DL data transmitted in the reference time slot 640 from the UE at the time point when the BS initiates the channel access procedure 670, the time point when the BS selects the N value to perform the channel access procedure, or the time point immediately before this, the BS can determine the contention window by using the UE's DL data reception result with respect to the reference time slot, wherein the reference time slot is a reference time slot in the DL signal transmission interval of the most recently transmitted among the reception results of the DL data channel previously received from the UE. The BS can determine the size of the contention window to be used in the channel access procedure 670 by using the DL data reception result of the DL data transmitted through the DL data channel in the reference time slot, which result is received from the UE.

[0159] After the BS transmits a DL signal through a channel access procedure (e.g., CW_p=15) configured based on a channel access priority level 3 (p=3), when at least 80% of the reception results from the UE regarding the DL data transmitted to the UE through the DL data channel in the reference time slot in the DL signal transmitted in the unlicensed band are determined as NACK, the BS may increase the contention window from the initial value (CW_p=15) to the next contention window value (CW_p=31). However, the ratio of 80% is merely an example, and thus various modifications may be made.

[0160] When at least 80% of the reception results from the UE are determined to be not NACK, the BS may maintain the value of the contention window to its current value, or may change the value of the contention window to the initial value of its contention window. The change of the contention window may be applied to all channel access priority levels in common, or may be applied only to the channel access priority level used for the channel access process. A method will now be described by which the BS determines a reception result effective for a change in the size of the contention window, which is a reception result in a DL data reception result of DL data sent or reported by the UE to the BS regarding DL data sent through a DL data channel in a reference time slot, in which the change in the size of the contention window is determined, that is, the method is a method for determining a Z value. However, the present disclosure is not limited to the following examples.

[0161] When the BS sends one or more codewords (CWs) or TBs to one or more UEs in a reference time slot, the BS may determine the Z value as the ratio of NACKs sent or reported by the UE to the BS among the reception results of the TBs received by the UE in the reference time slot. For example, when two CWs or two TBs are sent to one UE in a reference time slot, the BS may receive or be reported DL data signal reception results about the two TBs from the UE. When the ratio of NACKs in the two reception results (Z) is greater than or equal to a threshold value (e.g., Z=80%) predefined or configured between the BS and the UE, the BS may change or increase the size of the contention window.

[0162] When the UE bundles DL data reception results about one or more time slots (e.g., M time slots) including the reference time slot, and transmits or reports the bundled reception results to the BS, the BS may determine that the UE has transmitted the M reception results. The BS may determine the Z value as the ratio of NACKs among the M reception results, and may change, maintain, or reset the size of the contention window.

[0163] When the reference time slot is the second time slot of two time slots included in one subframe, or a DL signal is sent in the next symbol after the first symbol starting from the reference time slot, the BS can determine the reference time slot and the next symbol as the reference time slot, and can determine the Z value as the ratio of NACK in the reception result of DL data received in the reference time slot sent by the UE or reported to the BS.

[0164] When the scheduling information or DCI of the DL data channel sent by the BS is sent by the same cell or frequency band as the cell or frequency band in which the DL data channel is sent, or when the scheduling information or DCI for the DL data channel sent by the BS is sent in an unlicensed band but by a cell or frequency different from the cell in which the DL data channel is sent, when it is determined that the UE does not send the reception result of the DL data received in the reference time slot, and when it is determined that the reception result of the DL data sent by the UE is determined to be at least one of discontinuous transmission (DTX), NACK / DTX, or any state, the BS can determine the Z value by determining the reception result from the UE as NACK.

[0165] When the scheduling information or DCI of the DL data channel to be transmitted by the BS is transmitted in the licensed band, and it is determined that the reception result of the DL data transmitted by the UE is determined as at least one of DTX, NACK / DTX, or any state, the BS may not reflect the reception result from the UE to Z, which is a reference value in the change of the contention window. That is, the BS may discard (ignore) the reception result from the UE, and may determine the Z value.

[0166] When scheduling information or DCI for a DL data channel to be sent by the BS is sent in a licensed band, and a reception result of DL data about a reference time slot sent by the UE or reported to the BS includes a case where the BS does not actually send the DL data (no transmission), the BS can discard the reception result of the DL data sent by the UE or reported to the BS, and can determine the Z value.

[0167] Figure 7 A channel access procedure in an unlicensed frequency band in a wireless communication system according to one embodiment is shown.

[0168] refer to Figure 7, a communication device that performs a frame-based channel access process may periodically transmit and receive signals according to a fixed frame period (FFP) 700. The FFP 700 may be declared or configured by a communication device (e.g., a BS) and may be configured between 1 ms and 10 ms. A channel access process (or pure channel access (CCA)) for an unlicensed band may be performed immediately before the start of each frame period 730, 733, or 736, and the channel access process may be performed during a fixed time period or an observation time slot as in a channel access process of type 2. Based on the result of the channel access process, when it is determined that the unlicensed band is in an idle state or is an idle channel, the communication device may transmit or receive signals during up to 95% of the time of the FFP 700 (hereinafter referred to as COT 710) without separately performing a channel access process. In this regard, at least 5% of the time of the FFP 700 corresponds to an idle period 720, during which signals cannot be transmitted or received, and the channel access process may be performed in the idle period 720.

[0169] The advantage of the frame-based channel access process is that the frame-based channel access process can be relatively simple compared to the service-based channel access process, and the channel access to the unlicensed band can be performed periodically. However, because the time to start the channel access process is fixed, the disadvantage of the frame-based channel access process is that the probability of accessing the unlicensed band is reduced compared to the service-based channel access process.

[0170] Figure 8 Scheduling and feedback in a wireless communication system according to one embodiment is shown.

[0171] The BS may send control information including DL and / or UL scheduling to the UE. The BS may send DL data to the UE. The UE may send HARQ-ACK information, which is feedback about the DL data, to the BS. Alternatively, the UE may send UL data to the BS.

[0172] In the NR system, the UL and DL HARQ schemes may include an asynchronous HARQ scheme in which the time point of data retransmission is not fixed. For example, for DL, when the BS receives HARQ NACK from the UE as feedback on the initial transmission data, the BS can arbitrarily determine the transmission time point of the data to be retransmitted according to the scheduling operation. The UE can perform buffering on the data determined to be erroneous according to the decoding result of the received data for the HARQ operation, and then the buffered data can be combined with the data retransmitted from the BS.

[0173] refer to Figure 8, showing a resource domain for transmitting a data channel in a 5G or NR communication system. The UE may monitor and / or search for a PDCCH 810 in a DL control channel (e.g., PDCCH) domain (hereinafter, a control resource set (CORESET) or a search space (SS)) configured in an upper layer signal from the BS. The PDCCH domain consists of time resource domain information 814 and frequency resource domain information 812, the time resource domain information 814 may be configured as a symbol unit, and the frequency resource domain information 812 may be configured as an RB or a group unit of RBs.

[0174] When the UE detects the PDCCH 810 in the time slot i 800, the UE may obtain the DCI transmitted through the detected PDCCH 810. The UE may obtain scheduling information 840 of a DL data channel or a UL data channel from the received DCI. That is, the DCI may include at least information requesting the UE to receive a resource region (or a PDSCH transmission region) of a DL data channel (or a PDSCH) transmitted from the BS, or information of a resource region allocated from the BS to the UE for transmitting a UL data channel (or a physical UL shared channel (PUSCH)).

[0175] A case of scheduling a UE for transmission of a UL data channel (or PUSCH) will now be described as an example.

[0176] Upon receiving the DCI, the UE may obtain a slot index or offset information (K) related to reception of the PUSCH from the DCI, and may determine a slot index for reception of the PUSCH. According to the received offset information (K) of the received slot i 800 based on the received PDCCH 810, the UE may determine that the UE is scheduled to transmit the PUSCH in slot i+K 805. The UE may determine slot i+K 805 or a PUSCH start symbol or time in slot i+K 805 based on the received offset information (K) based on the CORESET of the received PDCCH 810.

[0177] The UE may obtain information about the PUSCH transmission time-frequency resource domain 840 in the PUSCH transmission time slot 805 from the DCI. The PUSCH transmission frequency resource domain information 830 may include information about a PRB or a group unit of a PRB. The PUSCH transmission frequency resource domain information 830 may be information about a domain included in an initial UL bandwidth (BW) or an initial UL BWP, which is determined or configured through an initial access procedure. When the UE is configured with a UL BW or a UL BWP through an upper layer signal, the PUSCH transmission frequency resource domain information 830 may be information about a domain included in the UL BW or the UL BWP configured through the upper layer signal.

[0178] The PUSCH transmission time resource field information 825 may be information about a symbol or symbol group unit, or may be information indicating absolute time information. The PUSCH transmission time resource field information 825 may be represented by 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 added to the DCI as a field or value. The UE may send the PUSCH in the PUSCH transmission resource field 840 determined according to the DCI.

[0179] Upon receiving the PDSCH 840, the UE may transmit feedback (e.g., HARQ-ACK / NACK) regarding the reception result of the PDSCH 840 to the BS. The UE may determine the transmission resource of the UL control channel (e.g., PUCCH) 870 for transmitting the reception result of the PDSCH 840 based on the PDSCH to HARQ timing indicator and the PUCCH resource indicator indicated by the DCI 810 that schedules the PDSCH 840. That is, when the UE receives K1 as the PDSCH to HARQ timing indicator from the DCI 810, the UE may transmit the PUCCH 870 in the slot i+K+K1 850 after K1, starting from the reception slot 805 of the PDSCH 840.

[0180] The BS may configure one or more K1 values ​​for the UE via higher layer signaling, or, as described above, may indicate a specific K1 value to the UE via DCI. K1 may be determined based on the HARQ-ACK processing capability of the UE, i.e., based on the minimum time period for the UE to receive the PDSCH and generate and report the HARQ-ACK regarding the PDSCH. Before configuring the UE with a K1 value, the UE may use a predefined value or a default value as the K1 value.

[0181] The transmission resources for PUCCH 870 in PUCCH transmission slot 850 may include PUCCH transmission in resources indicated by the PDCCH resource indicator in DCI 810. When multiple PUCCH transmissions are configured or indicated for PUCCH transmission slot 850, the UE may perform PUCCH transmission in PUCCH resources other than the resources indicated by the PDCCH resource indicator.

[0182] In a 5G communication system, in order to dynamically change the DL signal transmission interval and the UL signal transmission interval in a time division duplex (TDD) system, information about whether each of the OFDM symbols constituting a time slot is a DL symbol, a UL symbol, or a flexible symbol may be indicated by SFI. In response to UE-specific control information or scheduling information, a symbol indicated as a flexible symbol may be neither a DL symbol nor a UL symbol, or may be a symbol that can become a DL symbol or a UL symbol. A flexible symbol may include a guard interval for the process of switching from DL to UL.

[0183] The SFI can be sent to multiple UEs simultaneously through a UE group (or cell) common control channel. That is, the SFI can be sent through a PDCCH that is CRC-scrambled by a UE-specific identifier (C-RNTI) and a different identifier (e.g., SFI-RNTI). The SFI may include information about N time slots, where N may be an integer or natural number greater than 0, or may be a value in a set of predefined available values ​​(including 1, 2, 5, 10, 20, etc.). The value is configured to the UE by the BS through an upper layer signal. The BS can configure the size of the SFI information to the UE through an upper layer signal. An example of a time slot format that can be indicated by the SFI is shown in Table 3 below.

[0184]

Table 3

[0185]

[0186]

[0187]

[0188] In Table 3, D represents DL, U represents UL, and F represents flexible symbols. In Table 3, the total number of available time slot formats is 256. In the current NR system, the maximum size of the SFI information bit is 128 bits. The SFI information bit refers to a value that can be configured by the BS to the UE in an upper layer signal (e.g., dci-PayloadSize). By introducing one or more additional time slot formats or modifying at least one existing time slot format, a cell operating in an unlicensed band can configure and indicate additional time slot formats, as shown in Table 4 below.

[0189] Table 4 shows an example of a slot format by which one slot is composed of UL (U) and flexible symbols (F).

[0190]

Table 4

[0191]

[0192] The SFI information may include the time slot formats of multiple service cells, and the time slot formats of the service cells may be identified by their respective service cell IDs. For each service cell, a time slot format combination of SFIs of one or more time slots may be included. For example, when the size of the SFI information is 3 bits and the SFI information is configured by an SFI for one service cell, the 3-bit SFI information may be one of 8 SFIs or SFI combinations (hereinafter referred to as SFIs), and the BS may indicate one SFI of the 8 SFIs (hereinafter referred to as SFI information) through a UE group common DCI.

[0193] At least one of the 8 SFIs can be configured as an SFI for multiple time slots. Table 5 below shows an example of 3-bit SFI information configured as the time slot format in Table 4. Five time slot format combination IDs (time slot format combination IDs 0, 1, 2, 3, 4) in the SFI information correspond to the SFI of one time slot, and the remaining three time slot format combination IDs (time slot format combination IDs 5, 6, 7) can correspond to the SFI of four time slots and can be sequentially applied to the four time slots.

[0194]

Table 5

[0195] 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

[0196] The UE may receive configuration information about a PDCCH in which the UE is requested to detect SFI information through an upper layer signal, and may detect SFI based on the configuration information. At least one of the configuration of a CORESET in which the UE is requested to detect SFI information, a search space configuration, RNTI information used in CRC scrambling of a DCI carrying SFI information, a search space period, or offset information may be configured for the UE through an upper layer signal.

[0197] Fig.9A A COT in a wireless communication system according to an embodiment is shown.

[0198] refer to Fig.9A, requesting the UE to detect SFI information from PDCCH regions 920, 922, and 924, where the PDCCH region period corresponds to 2 time slots. In response to the configured PDCCH region and its period, the UE can detect DCI scrambled by the SFI identifier (e.g., SFI-RNTI or new RNTI) from PDCCH regions 920, 922, and 924 (or CORESET) in time slot n 900, time slot n+2 902, and time slot n+4 904, and can obtain the SFI of two time slots from the detected DCI. The detected DCI may include SFI information of at least two time slots, and the indication of how many time slots the SFI included in the DCI is to indicate can be configured by an upper layer signal. Configuration information about how many time slots the SFI included in the DCI will indicate can be included in the upper layer signal configuring the SFI information.

[0199] For example, the UE may obtain a plurality of pieces of SFI information 910 and 911 of slot n 900 and slot n+1 901 from the PDCCH region 920 of slot n 900. The plurality of pieces of SFI information 910, 911, 912, 913, and 914 may have at least one value in the format of Table 3. However, a new format different from the format of Table 3 may also be possible.

[0200] When the BS transmits SFI information in an unlicensed band, specifically, when the SFI information includes SFIs of a plurality of time slots, the BS may not be able to determine SFI information of at least one time slot in response to whether channel access to the unlicensed band is activated. When the BS transmits a plurality of pieces of SFI information 914 and 915 of time slot n+4 904 and time slot n+5 905, the BS is requested to determine how to indicate SFI information of time slot n+5 905. For example, the BS may indicate that SFI for a period of time other than COT is flexible.

[0201] Hereinafter, a method of allocating UL resources will be described.

[0202] UL resources for transmitting signals or data may be allocated continuously or discontinuously, and when a specific resource allocation type is determined, information indicating the UL resource allocation may be interpreted based on the specific resource allocation type. In the 3GPP standard, signals and channels are used separately, but in the present disclosure, UL transmission signals or UL transmission channels may not be separated but may be used interchangeably, or UL transmission signals may be used to indicate or represent both UL transmission signals and UL transmission channels. This is because the scheme for determining the UL resource allocation type or the position for starting UL transmission as described in the present disclosure may be commonly applied to both the UL transmission signal and the UL transmission channel. In this case, the scheme for determining the UL resource allocation type or the position for starting UL transmission proposed in the present disclosure may be independently applied to each of the UL transmission signal and the UL transmission channel without additional classification or description.

[0203] -UL resource allocation type 0

[0204] The UL resource allocation type 0 scheme allocates resources in RB group (RBG) units consisting of P consecutive RBs. P is the size of the RBG and can be configured as one of configuration 1 and configuration 2 through an upper layer signal (e.g., the value of rbg-size of pusch-Config), and P can be determined based on one of the multiple pieces of information included in the upper layer signal and the size of the activated UL BWP, as shown in Table 6.

[0205] Table 6 shows the size of P based on the size of BWP and the RBG setting value. The size of BWP indicates the number of PRBs constituting the BWP.

[0206]

Table 6

[0207] Carrier bandwidth portion size Configuration 1 Configuration 2 1-36 2 4 37-72 4 8 73-144 8 16 145-275 16 16

[0208] Composition UL BWP N BWP The number of RBGs N RBG Can be determined as N RBG =ceiling(N BWP size +N BWP start modP) / P). The first RBG (RBG 0 ) is PN BWP start mod P. When (N BWP start +N BWP size )mod P is greater than 0, the last RBG (RBG last ) is of size (N BWP start +NBWP size ) mod P, when (N BWP start +N BWP size )mod P is not greater than 0, the last RBG (RBG last ) is of size P.

[0209] The size of the RBGs except the first and last RBGs is P. In this case, N BWP start Refers to the CRB where the BWP starts relative to CRB0, which can be understood as the point in CRB where a specific BWP starts. BWP size Refers to the number of RBs included in the BWP.

[0210] The length (or size or number of bits) of the frequency resource allocation information is equal to N RBG , and the UE may be configured or scheduled in an RBG unit having resources in which the UE is allocated by N RBG The bitmap configured with 10 bits configures or schedules UL transmission for each RBG. For example, the UE can determine that the RBG area configured as 1 in the bitmap is a resource allocated for UL transmission, while the RBG area configured as 0 is not a resource allocated for UL transmission. The RBG bitmap is arranged and mapped sequentially (in ascending order) on an axis with increasing frequency. Continuous or discontinuous RBGs can be allocated for UL transmission.

[0211] -UL resource allocation type 1

[0212] The UL resource allocation type 1 scheme allocates contiguous frequency resources in the activated UL BWP. The frequency resource allocation information of the UL resource allocation type 1 scheme can be indicated to the UE through the resource indication value (RIV). The length (or size or number of bits) of the frequency resource allocation information is equal to the ceiling (log 2 (N BWP (N BWP +1) / 2). RIV indicates the starting RB for frequency resource allocation (RB Start ) and L consecutively allocated RBs (L RB ). However, the present disclosure is not limited thereto.

[0213] if Then RIV=N BWP (L RBs -1)+RB start

[0214] Otherwise, RIV = N BWP (N BWP -L RBs-1)+(N BWP -1-RBstart)

[0215] Among them, L RBs ≥1 and should not exceed N BWP -RBstart

[0216] Among them, N BWP Indicates the size of the activated UL BWP, which is represented by the number of PRBs, RB Start Indicates the first PRB where UL resource allocation starts. RB The initial UL BWP size N is used when one of the DCIs (e.g., DCI format 0_0) configuring or scheduling UL transmission is sent in the common search space (CSS) (hereinafter referred to as UL grant). BWP,0 .

[0217] For a DCI format in a UL grant, such as DCI format 0_0 transmitted in a UE-specific common search space (USS), the size or number of bits of the frequency resource allocation information of the UL grant is based on the size of the initial BWP (N initial,BWP ), but when the UL grant is a DCI that schedules another activated BWP, the RIV value is RB Start =0, K, 2K, ..., (N initial,BWP -1) K and L RB =K, 2K, ..., N initial,BWP K, and can be configured as follows.

[0218] if Then RIV=w initial，BWP (L′ RNs -1)+RB′ start

[0219] Otherwise, RIV = N initial，BWP (N initial，BWP -L′ RBs -1)+(N initial，BWP -1-RB′ start )

[0220] in, L′ RBs =N initial，BWP -RB′ start

[0221] -UL resource allocation type 2

[0222] The UL resource allocation type 2 scheme allocates resources so that the frequency resources used to transmit the UL signal or channel are distributed throughout the activated UL BWP, in which case the distances or gaps between the allocated frequency resources are equal. With UL resource allocation type 2, resources are evenly allocated across the entire frequency band, so that UL resource allocation type 2 can be limitedly applied to UL signal and channel transmission, where the carrier, cell or BWP operates in an unlicensed band that is requested to meet the requirements of power spectral density (PSD) and frequency allocation (e.g., occupied channel bandwidth (OCB) conditions).

[0223] Fig. 9B A frequency resource allocation type in a wireless communication system according to an embodiment is shown.

[0224] refer to Fig. 9B In the UL resource allocation type 2 scheme, the UE is configured to perform UL signal transmission or reception with the BS in the BWP 930 and is scheduled with UL data channel transmission. In this regard, it is assumed that the BWP 930 consists of 51 PRBs. According to the UL resource allocation type 2 scheme, the 51 PRBs can be configured L (in Fig. 9B There are L=5 resource allocation sets in the resource allocation set, and each of the resource allocation sets can be composed of or PRB. Fig. 9B In the embodiment, the first resource allocation set 940 includes 11 PRBs (#i, #i+5, #i+10, #i+15, ..., #i+45, #i+50), and another resource allocation set, for example, the third resource allocation set 950, may include 10 PRBs (#i+3, #i+8, #i+13, #i+18, ..., #i+48).

[0225] The number of PRBs included in a resource allocation set may be different depending on the size of a BWP or the number of PRBs in a BWP. The UE may be allocated one or more resource allocation sets configured as described above, and may be allocated contiguous resource allocation sets (e.g., resource allocation sets #0, #1 or #2, #3, #4) in a manner similar to the UL resource allocation type 1 scheme (e.g., allocation based on RIV values), or may be allocated contiguous or non-contiguous resource allocation sets in a manner similar to the UL resource allocation type 0 scheme (e.g., bitmap-based allocation).

[0226] When the UE is allocated a continuous resource allocation set, the UE may determine the frequency resource region (or resource allocation set) allocated with the RIV in a manner similar to UL resource allocation type 1, where the RIV is used as the starting resource allocation set RB for frequency resource allocation. Start and L consecutive resource allocation sets, at this point, the RIV is as follows.

[0227] if Then RIV=N(L-1)+RB start

[0228] Otherwise, RIV = N(NL-1) + (N-1-RB start )

[0229] For example, RIV=0 indicates the first resource allocation set or resource allocation set #0, indicating that Fig. 9B The resource allocation set consisting of PRB #i, #i+10, #i+20, ..., #i+50 has been allocated. In this case, the length (or size or number of bits) of the frequency resource allocation information is equal to the ceiling (log 2 (L(L+1) / 2).

[0230] When allocating consecutive or non-consecutive resource allocation sets to the UE by using a bitmap, the bitmap may be configured with L bits, the L bits respectively indicating L resource allocation sets, the resource allocation sets configuring the BWP 930 in ascending order of frequency resources or in ascending order of resource allocation set indexes, and the BS may allocate the resource allocation sets through the bitmap. Fig. 9B In the example, using a bitmap configured with 5 bits, the location of the resource allocation set can be indicated by the bitmap. In this regard, the bitmap "10000" indicates that the first domain set is allocated, that is, Fig. 9B The bitmap 00010 indicates the allocation of the fourth resource allocation set, which consists of PRB #i, #i+10, #i+20, ..., #i+50. Fig. 9B In this case, the length (or size or number of bits) of the frequency resource allocation information is equal to l.

[0231] -UL resource allocation type 3

[0232] Fig. 9C The type of frequency resource allocation in a wireless communication system according to an embodiment is shown. Specifically, Fig. 9C UL resource allocation type 3 is shown.

[0233] refer to Fig. 9C, the UL resource allocation type 3 scheme allocates resources so that frequency resources for transmitting UL signals or channels are distributed over the entire activated UL BWP, in which case the allocated resource group (or allocated resource block or allocated resource cluster) as a continuous resource (e.g., allocated resource group 951 or 961) is distributed as a whole in the BWP in a repeated transmission or the like manner (e.g., allocated resource groups 951, 952, and 953 to allocated resource groups 961, 962, 963). That is, the allocated resource group 951 as a continuous resource may be repeatedly present in the frequency resources (e.g., allocated resource groups 951, 952, and 953), and therefore, a plurality of allocated resource groups may exist in the BWP. With UL resource allocation type 3, continuous allocated resource groups (or allocated resource blocks or clusters) are distributed in the frequency band, so that UL resource allocation type 3 can be limitedly applied to UL signal and channel transmission, where the carrier, cell, or BWP operates in an unlicensed band that is requested to meet the requirements of PSD and frequency allocation such as OCB conditions.

[0234] In a similar manner to the frequency, the UE can be configured with the time resource domain of the UL data channel by the following method. The time resource domain of the UL data channel can be indicated to the UE by the start and length indicator value (SLIV). The SLIV is determined by the start symbol S for time resource allocation and the L symbols continuously allocated in the time slot. When (L-1) is less than or equal to 7, the SLIV is 14·(L-1)+S, and when (L-1) is greater than 7, the SLIV is 14·(14-L+1)+(14-1-S). In this case, L has a value greater than 0 and less than or equal to 14.

[0235] In addition, the BS may instruct the UE to send a UL signal in an unlicensed band relative to a UL signal or channel transmission start position or time (hereinafter referred to as a position), or the UE may determine the position. For example, the BS may indicate or configure the UE through a DCI or an upper layer signal the start symbol of the UL signal transmission and the length of the UL signal transmission in a specific time slot, or the start symbol of the UL signal transmission and the end symbol of the UL signal transmission. The UE may be additionally configured with a transmission start position in the first symbol of the indicated or configured UL signal transmission.

[0236] At least one of the DCI formats used to transmit the DCI may be a DCI format including an SFI field. In this regard, the DCI format including the SFI field may transmit group common control information to one or more UE groups.

[0237] The UE may be configured to receive or search for and detect a DCI format including an SFI field through an upper layer signal (e.g., SlotFormatIndicator). The DCI format may include the SFI of one or more serving cells (e.g., a serving cell set configured by slotFormatCombToAddModList). The DCI format may be sent to the UE from at least one cell in the serving cell set or another cell. The cell that sends SFI information or DCI related to one or more serving cells (the DCI from the cell to be received by the UE) is referred to as cell 1, and the cell that obtains and determines the SFI information through the DCI sent from cell 1 is referred to as cell 2.

[0238] When not described separately in the present disclosure, the DCI format refers to a DCI including at least an SFI field, and the DCI refers to a signal transmitted through a group common CORESET or a group common search space and CRC-scrambled by an RNTI configured by an upper layer signal. In addition, when not described separately in the present disclosure, the UE is configured to receive or search for and detect a DCI format including at least an SFI field by an upper layer signal (e.g., SlotFormatIndicator). However, the present disclosure is not limited thereto.

[0239] Example 1

[0240] In Embodiment 1, it is assumed that an additional field for notifying information about COT exists in the SFI field of the DCI format. COT refers to a time period during which a BS attempting to communicate with a UE by using an unlicensed band performs a channel access procedure to occupy the unlicensed band and then performs communication. COT can be represented by symbol units. The value indicated by the COT field can be a value of one of the configured X COTs that the BS can indicate to the UE through an upper layer signal. The BS can predefine the size of the COT field to 8 bits, or can configure the size of the COT field through an upper layer signal, and can indicate one of a maximum of 64 available COT values ​​or the number of symbols to the UE through DCI.

[0241] One of the values ​​configured by the upper layer signal is indicated to the UE through the DCI, and the UE can determine the COT of the BS. That is, the UE can determine the time period from the time or symbol starting from the transmission or reception of the first symbol of the DCI including the COT field to the time or symbol of the COT information indicated by the DCI as the COT of the BS. Based on the determined COT information, depending on whether the UL transmission is performed within the COT of the BS, the UE can differently determine the channel access procedure type to be performed for the UL transmission indicated by the UL / DL scheduling information or the UL transmission configured by the upper layer signal, or can change the channel access procedure type. The UE can be instructed by the UL / DL scheduling information to use channel access procedure type 3 for UL transmission.

[0242] When UL transmission can be performed within the COT of the BS, the UE may perform channel access procedure type 1 or channel access procedure type 2, and according to the result thereof, the UE may or may not perform UL transmission. When UL transmission is initiated within 16μs or 16μs+TA time immediately after the symbol at which DL transmission of the BS ends, the UE may perform channel access procedure type 1. When UL transmission is initiated after 16μs or 16μs+TA time immediately after the symbol at which DL transmission of the BS ends, the UE may perform channel access procedure type 2. That is, for UL transmission performed in the COT of the BS, in response to the result of the channel access procedure, the UE may switch to channel access procedure type 2 as the indicated or configured channel access procedure, and perform the channel access procedure, and may or may not perform UL transmission.

[0243] Fig.10 Time resource allocation types in a wireless communication system according to an embodiment are shown.

[0244] refer to Fig.10, when the BS attempts to perform communication with the UE by occupying a period of time after the channel access procedure is completed, for example, an unlicensed band from a first time or symbol 1050 to a second time or symbol 1060, the COT of the BS corresponds to 42 symbols 1070. The BS may transmit COT information in a DL control channel transmission region or CORESET 1021 through a DCI format. Since the COT information is transmitted through a DCI format in the DL control channel region 1021 of the time slot n+1 1001, its COT may be less than or equal to 35 symbols 1075. The BS may transmit COT information corresponding to 24 symbols in the DL control channel region 1021 of the time slot n+1 1001 through a DCI format to the UE, and may transmit to the UE that it is 21 symbols in the DL control channel region 1022 and that it is 7 symbols in the DL control channel region 1023. The UE may determine the COT of the BS as a duration (period) from the first symbol in which the received DCI has been transmitted to the COT information indicated by the DCI. The BS may transmit COT information and SFI information about a slot included in the COT to the UE through DCI.

[0245] The BS may transmit at least the SFI X1 1011 of the time slot n+1 1001 in the DL control channel region 1021 of the time slot n+1 1001 through the DCI format. The BS may transmit at least the SFI X1 1011 of the time slot n+1 1001 and the SFI X2 1012 of the time slot n+2 1002 through the DCI. The COT of the BS may start or end in any symbol of the time slot. However, because the SFI may indicate a time slot or a time slot format of 14 symbols, a situation may occur where the SFI indicates a time other than the COT of the BS. For example, when the BS transmits the SFI X3 1013 of the time slot n+3 1003 to the UE, the COT of the BS corresponds to the time when the COT ends within the time slot n+3 1003. The BS may reoccupy the channel using the time after the COT of the BS by performing the channel access procedure again, or another UE or BS may occupy and use the channel, and therefore, the SFI information in the time other than the COT of the BS is invalid information. That is, when the UE receives a DCI having an SFI field (in which there is an additional field for notifying COT information), the UE may discard or may not apply the SFI information about the symbol 1085 outside the COT, which is indicated by the DCI. The UE may determine that the SFI information indicated by the DCI is valid only for the symbol 1080 included in the COT indicated by the DCI, and may determine that the SFI information of the symbol 1085 outside the COT is not provided or indicated, or may determine that it has failed to detect the DCI, and may operate as follows for the symbol 1085 outside the COT and the time slot or symbol 1004.

[0246] -The UE may perform a channel access procedure according to a channel access procedure type indicated or configured by the BS, and according to the result thereof, the UE may perform or not perform UL transmission.

[0247] - The UE may receive a DL data channel or a channel state information reference signal (CSI-RS) indicated by another DCI (eg, UL / DL scheduling DCI).

[0248] - The UE may transmit a UL data channel, a UL control channel, a physical random access channel (PRACH), or a sounding reference signal (SRS) indicated by another DCI (eg, UL / DL scheduling DCI or a DCI indicating transmission of an SRS).

[0249] -UE can receive and detect PDCCH through CORESET and control space configured in symbols.

[0250] -UE can receive and detect PDCCH through CORESET and control space configured in symbols.

[0251] -The UE may not receive the PDSCH or CSI-RS configured for the UE to receive through a higher layer signal.

[0252] -When the UE determines that the SFI information is not provided or indicated by the upper layer signal (e.g., Cat4LBT-Exception), or the UE is configured to send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer information for the UE to send in a symbol for which the DCI for sending the SFI information is not received, the UE may send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer signal for the UE to send in symbol 1085. A UE that is not provided with an upper layer signal (e.g., Cat4LBT-Exception) may not send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer signal for the UE to send.

[0253] Example 2

[0254] In Embodiment 2, it is assumed that an additional field for notifying information about COT does not exist in the SFI field of the DCI format. COT refers to a time period during which a BS attempting to communicate with a UE by using an unlicensed band performs a channel access procedure to occupy the unlicensed band and then performs communication. COT can be expressed in absolute time or symbol units. When there is no information for separately indicating COT, the UE can implicitly determine the COT of the BS by using the following method.

[0255] For example, the UE may determine that the time slot indicated by the SFI in the DCI format is a time slot corresponding to the COT of the BS or is included in the COT of the BS. Based on the determined COT information, depending on whether the UL transmission is performed within the COT of the BS, the UE may differently determine the channel access procedure type to be performed for the UL transmission indicated by the UL / DL scheduling information or the UL transmission configured by the upper layer signal, or may change the channel access procedure type.

[0256] The UE may be instructed to use channel access procedure type 3 for UL transmission through UL / DL scheduling information. When UL transmission can be performed within the COT of the BS, the UE may perform channel access procedure type 1 or channel access procedure type 2, and depending on the result, the UE may or may not perform UL transmission. When UL transmission is initiated within 16μs or 16μs+TA time immediately after the symbol at which DL transmission of the BS ends, the UE may perform channel access procedure type 1. When UL transmission is initiated after 16μs or 16μs+TA time immediately after the symbol at which DL transmission of the BS ends, the UE may perform channel access procedure type 2. That is, for UL transmission performed in the COT of the BS, in response to the result of the channel access procedure, the UE may switch to channel access procedure type 2 as the indicated or configured channel access procedure, and perform the channel access procedure, and may or may not perform UL transmission.

[0257] Reference again Fig.10 , when the BS attempts to perform communication with the UE by occupying a period of time after the channel access procedure is completed, for example, an unlicensed band from time or symbol 1050 to time or symbol 1060, the COT of the BS corresponds to 42 symbols 1070. The BS may transmit SFI information about one or more time slots in the DL control channel transmission region or CORESET 1021 through a DCI format so that a UE having received the information may determine the COT of the BS. The BS may transmit SFI X1 1011 of at least time slot n+1 1001 in the DL control channel region 1021 of time slot n+1 1001 through a DCI format. The BS may transmit SFI X1 1011 of at least time slot n+1 1001 and SFI X2 1012 of time slot n+2 1002 through DCI. When receiving this information, the UE can determine the COT of the BS as time slot n+1 or the duration between time slot n+1 and time slot n+2 (indicated by the SFI), or can determine that time slot n+1 or time slot n+1 and time slot n+2 (indicated by the SFI) are time slots included in the COT of the BS.

[0258] The COT of the BS may start or end in any symbol of the time slot. However, since the SFI may indicate a time slot or a time slot format of 14 symbols, there may be a case where the SFI indicates a time other than the COT of the BS. For example, when the BS sends the SFI X3 1013 of the time slot n+3 1003 to the UE, the COT of the BS corresponds to the time when the COT ends in the time slot n+3 1003. When the SFI X3 1013 for the time slot n+3 1003 is indicated, the UE may determine that the time slot indicated by the SFI corresponds to the COT of the BS, and thus in Embodiment 2, it is recommended that the BS does not provide the SFI X3 1013 for the time slot n+3 1003 to the UE.

[0259] For symbols or slot n+3 1003 not included in the COT, the UE may determine that SFI information is not provided or indicated, or may determine that it has failed to detect DCI, and may operate with respect to the symbols as follows.

[0260] -The UE may perform a channel access procedure according to a channel access procedure type indicated or configured by the BS, and according to the result thereof, the UE may perform or not perform UL transmission.

[0261] - The UE may receive a DL data channel or CSI-RS indicated by another DCI (eg, UL / DL scheduling DCI).

[0262] - The UE may transmit a UL data channel, a UL control channel, a PRACH, or an SRS indicated by another DCI (eg, a UL / DL scheduling DCI or a DCI indicating transmission of an SRS).

[0263] -UE can receive and detect PDCCH through CORESET and control space configured in symbols.

[0264] -The UE may not receive the PDSCH or CSI-RS configured for the UE to receive through a higher layer signal.

[0265] -When the UE determines that the SFI information is not provided or indicated by the upper layer signal (e.g., Cat4LBT-Exception), or the UE is configured to send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer information for the UE to send in a symbol for which the DCI for sending the SFI information is not received, the UE may send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer signal for the UE to send in symbol 1085. A UE that is not provided with an upper layer signal (e.g., Cat4LBT-Exception) may not send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer signal for the UE to send.

[0266] Example 3

[0267] In Embodiment 3, it is assumed that an additional field for notifying information about COT exists in the SFI field of the DCI format. In addition, it is assumed that the DCI includes the SFI of multiple cells. For ease of description, in Embodiment 3, the cell that sends the DCI is referred to as cell 1, and the cell that determines the SFI information based on the DCI sent from cell 1 is referred to as cell 2. Therefore, the DCI includes the SFI field of cell 1 and the SFI field of cell 2. The base station or the core network can configure which SFI of the cell corresponds to which position, order or field in the DCI for the UE through an upper layer signal. The base station or the core network can configure which COT field of the cell corresponds to which position, order or field in the DCI for the UE through an upper layer signal.

[0268] Communication between the BS and the UE may be performed in the licensed band in both cell 1 and cell 2. In addition, the BS and the UE may be performed in the licensed band in cell 1 and the unlicensed band in cell 2, or the BS and the UE may be performed in the unlicensed band in cell 1 and the licensed band in cell 2. Both cell 1 and cell 2 may be performed in the unlicensed band in cell 1 and the UE may be performed in the licensed band in cell 2.

[0269] For ease of description, in Embodiment 3, it is assumed that cell 1 performs communication between the BS and the UE in a licensed band, and cell 2 performs communication between the BS and the UE in an unlicensed band. It is assumed that the SFI field includes an additional field for notifying information about the COT of the cell performing communication between the BS and the UE in the unlicensed band, but the SFI field may also include an additional field for notifying information about the COT of the cell performing communication between the BS and the UE in the licensed band.

[0270] Fig.11 Time resource allocation types in a wireless communication system according to an embodiment are shown.

[0271] refer to Fig.11 Until cell 1 initiates transmission or configuration of DCI and generates information to be included in the DCI, the BS cannot determine whether a channel access procedure may be performed on cell 2 or is being performed on cell 2. As another example, the BS may be performing or may fail to perform configuration of SFI information about at least one of the time slots of cell 2.

[0272] When cell 1 transmits DCI, the DCI should include SFI information and COT information related to cell 2, but at least one of the SFI information or COT information related to cell 2 may not be determined. Specifically, in the unlicensed band, the UE determines the type of channel access procedure to be performed for UL transmission, or determines whether to perform UL / DL transmission or reception, based on the SFI information and COT information related to cell 2. Therefore, the SFI information and COT information related to cell 2 must be correctly transmitted.

[0273] When DCI is sent in a time, symbol or time slot when the BS has not completed the channel access process on cell 2, the UE that has received the SFI information and COT information related to cell 2 should determine, based on the SFI information related to cell 2 and the COT information, that the BS has failed to complete the channel access process on cell 2, that the BS has failed to occupy the channel in cell 2, that SFI information is not provided, or that COT information is not provided.

[0274] When the BS sends SFI information and COT information related to at least one cell (e.g., cell 2) whose SFI configuration or COT information cannot be determined, the BS may configure or indicate the COT of the cell to be 0, may configure or indicate a value predefined between the BS and the UE, or may configure or indicate a specific value configured to the UE through an upper layer signal, so that the UE may discard at least the SFI configuration and COT information from the sent information related to the cell, or may determine that the SFI configuration and COT information are not provided.

[0275] The predetermined value or the value configured by the upper layer signal may be one of a true value and a positive number, or one of a negative value and a non-numeric value. For a cell that receives the SFI information and the COT information through the DCI, when the received COT corresponds to 0, is a value predefined with the BS, is a specific value configured to the UE through the upper layer signal, is a negative value, or is a non-numeric value predefined or configured by the upper layer signal, the UE may discard at least the SFI configuration and the COT information in the transmitted cell-related information, may determine that the DCI is not detected, or may determine that the SFI configuration and the COT information are not provided.

[0276] When the BS transmits SFI information and COT information related to a cell (e.g., cell 2) for which at least one of the SFI configuration or the COT information cannot be determined, the BS may perform one of the following with respect to the SFI of the cell:

[0277] - configure or indicate the SFI as a slotted format by which all symbols are indicated as flexible symbols,

[0278] - configure or indicate the SFI to a specific slot format, such as slot format 255 or a value corresponding thereto,

[0279] - configure or indicate the SFI to be a reserved value or a slot format corresponding thereto,

[0280] - configuring or indicating the SFI to a predefined value or a slot format configured by an upper layer signal (e.g., a null slot format that does not include slot format information or a value corresponding thereto, or an indication of using one or more of the slot format values ​​that are reserved as non-numeric values), or

[0281] - Indicating a slot format corresponding to an error to allow the UE to discard at least the SFI information to determine that no SFI is provided or that no DCI is received relative to the slot indicated as a value in the cell-related information transmitted.

[0282] In addition, the UE may perform determination based on a combination of two or more of the above-mentioned indication methods. When the BS indicates a time slot format corresponding to an error, for example, when the BS indicates a time slot format with a number of time slots less than the number of time slots of the configured DCI interval, the BS may indicate the time slot format of the time slot to be indicated by using a reserved value.

[0283] When indicating a slot format of 255, for example, when SFI information configured by an upper layer signal (e.g., tdd-UL-DL-ConfigurationCommon, tdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated) is not provided to the UE, the BS may use a slot format of 255 to allow the UE to determine that the slot format is not valid information. Even when the UE is not provided with SFI information configured by an upper layer signal, the BS may use a slot format of 255 to allow the UE to determine that the slot format is not valid information.

[0284] When the BS indicates a time slot format corresponding to an error, the BS may indicate through DCI that at least one of the symbols is a DL / UL symbol, which are indicated as UL / DL symbols through SFI information, which is configured through an upper layer signal, or the BS may indicate, for a specific time slot, a time slot format different from the time slot format already indicated through DCI.

[0285] The BS may indicate the slot format only for a slot corresponding to an interval shorter than the interval at which the DCI of the slot format is transmitted. When a value in a reserved slot format value (e.g., R) is used, the value or the slot format may be predefined between the BS and the UE, or may be configured by an upper layer signal. For example, one of the slot formats in 62-254 of Table 3 or one of the R values ​​corresponding thereto may be configured to the UE by an upper layer signal.

[0286] The operation of the UE may be further indicated by using a plurality of reserved values. For example, a first reserved value R1 may be used to indicate to the UE that, in the time slot for which the first reserved value R1 is indicated, UL transmission configured by the upper layer signal is possible. A second reserved value R2 may be used to indicate to the UE that, in the time slot for which the second reserved value R2 is indicated, UL transmission configured by the upper layer signal is not possible.

[0287] As another example, the first (or third) reserved value R1 can be used to indicate to the UE that the cell 2 is performing a channel access procedure in the time slot for which the first (or third) reserved value R1 is indicated. The second (or fourth) reserved value R2 can be used to indicate to the UE that the cell 2 has occupied the channel, but the SFI of the time slot for which the second (or fourth) reserved value R2 is indicated cannot be determined. In this regard, it is possible to define a time slot format corresponding to a reserved value. The reserved value R can be configured as an empty time slot format that does not include time slot format information, can be configured as a specific time slot format mode value (e.g., DUDUDUDU...), or can be configured as a specific value other than a time slot format represented by D / U / F or a non-numerical value.

[0288] For a cell from which SFI information is received via DCI, when the received SFI value is:

[0289] - a slotted format whereby all symbols are represented as flexible symbols,

[0290] - a slot format value of 255 or a specific slot format (e.g., a slot format configured as an empty slot format not including slot format information, a specific slot format mode value (e.g., DUDUDUDU . . . ), or a slot format represented by D / U / F) or a value corresponding thereto,

[0291] - a reserved value or a timeslot format corresponding thereto,

[0292] - a predefined value, a value configured by an upper layer signal, or a time slot format corresponding thereto,

[0293] -When the slot format corresponds to an error, the UE may discard at least the indicated SFI information from the transmitted cell-related information, may determine that it has failed to determine the DCI, or may determine that the SFI information is not provided. The UE may discard the SFI information and the COT information, or may determine that the COT information is not provided. In this case, the UE may perform a channel access procedure according to the channel access procedure type indicated or configured by the BS, and according to the result, the UE may perform or not perform UL transmission.

[0294] As described above, the UE may discard the provided SFI information, may determine that SFI information is not provided or indicated, or may determine that it has failed to determine the DCI, and may perform the following operations for symbols or time slots and symbols or time slots outside of the COT.

[0295] - The UE may receive a DL data channel or CSI-RS indicated by another DCI (eg, UL / DL scheduling DCI).

[0296] - The UE may transmit a UL data channel, a UL control channel, a PRACH, or an SRS indicated by another DCI (eg, a UL / DL scheduling DCI or a DCI indicating transmission of an SRS).

[0297] -UE can receive and detect PDCCH through the configured CORESET and control space in the symbol.

[0298] - The UE may not receive the PDSCH or CSI-RS configured to the UE for reception through a higher layer signal.

[0299] -When the UE determines that the SFI information is not provided or indicated by the upper layer signal (e.g., Cat4LBT-Exception), or the UE is configured to send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer information for the UE to send in the symbol for which the DCI for sending the SFI information is not received, the UE may send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer signal for the UE to send in symbol 1185. The UE that is not provided with the upper layer signal (e.g., Cat4LBT-Exception) may not send the SRS, PUCCH, PUSCH, or PRACH configured by the upper layer signal for the UE to send.

[0300] Example 4

[0301] In Embodiment 4, it is assumed that there is no additional field for notifying information about COT in the SFI field of the DCI format. In addition, it is assumed that the DCI includes the SFIs of multiple cells. For ease of description, in Embodiment 4, cell 1 sends DCI, and cell 2 determines the SFI information based on the DCI sent from cell 1. Therefore, the DCI includes the SFI field of cell 1 and the SFI field of cell 2. Through the upper layer signal of the base station or the core network, it is possible to configure the UE which SFI of the cell corresponds to which position, order or field in the DCI.

[0302] Both cell 1 and cell 2 may perform communication between the BS and the UE in a licensed band. In addition, cell 1 may perform communication between the BS and the UE in a licensed band, while cell 2 may perform communication between the BS and the UE in an unlicensed band, or cell 1 may perform communication between the BS and the UE in an unlicensed band, while cell 2 may perform communication between the BS and the UE in a licensed band. In this regard, both cell 1 and cell 2 may perform communication between the BS and the UE in an unlicensed band.

[0303] For convenience of description, in Embodiment 4, it is assumed that cell 1 performs communication between a BS and a UE in a licensed frequency band, and cell 2 performs communication between a BS and a UE in an unlicensed frequency band.

[0304] Reference again Fig.11 Until cell 1 initiates transmission or configuration of DCI and generates information to be included in the DCI, the BS cannot determine whether a channel access procedure may be performed on cell 2 or whether a channel access procedure is being performed on cell 2. As another example, the BS may be performing or may fail to perform configuration of SFI information about at least one of the time slots of cell 2.

[0305] When cell 1 transmits DCI, the DCI should include SFI information related to cell 2, but may not be able to determine the SFI information related to cell 2. Specifically, in the unlicensed band, the UE determines the COT of the BS through the SFI information related to cell 2, thereby determining the type of channel access procedure to be performed for UL transmission, or determining whether to perform UL / DL transmission or reception. Therefore, the SFI information related to cell 2 should be correctly transmitted.

[0306] When DCI is transmitted in a time, symbol, or time slot in which the BS has not completed the channel access procedure on cell 2, and the UE receives SFI information related to cell 2, the UE may determine the time slot in which the time slot format is indicated as the COT of the BS. Therefore, the UE should determine, based on the SFI indicated for cell 2, that the BS has not completed the channel access procedure on cell 2, that the BS has failed to occupy a channel in cell 2, that SFI information is not provided, or that COT information is not provided.

[0307] When the BS transmits the SFI of a cell (e.g., cell 2) for which at least one of the SFI configuration or the COT information cannot be determined, the BS may perform one of the following for the SFI of the cell:

[0308] - configure or indicate the SFI as a slot format by which all symbols are indicated as flexible symbols,

[0309] - configure or indicate the SFI to a specific slot format, such as slot format 255 or a value corresponding thereto,

[0310] - configure or indicate the SFI to be a reserved value or a slot format corresponding thereto,

[0311] - configuring or indicating the SFI to a predefined value or a slot format configured by an upper layer signal (e.g., a null slot format that does not include slot format information or a value corresponding thereto, or an indication of using one or more of the slot format values ​​that are reserved as non-numeric values), or

[0312] -Indicating a slot format corresponding to an error to allow the UE to discard at least the SFI information to determine that the SFI is not provided, or to determine that the DCI is not received relative to the slot indicated as the value in the cell-related information transmitted. In addition, the UE can perform determination based on a combination of two or more of the above-mentioned indication methods. When the BS indicates a slot format corresponding to an error, for example, when the BS indicates a slot format with a smaller number of slots than the number of slots in which the DCI interval is configured, the BS can indicate the slot format of the slot to be indicated by using a reserved value.

[0313] When indicating a slot format of 255, for example, when SFI information configured by an upper layer signal (e.g., tdd-UL-DL-ConfigurationCommon, tdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated) is not provided to the UE, the BS may use the slot format of 255 to allow the UE to determine that the slot format is not valid information. Even when the UE is not provided with SFI information configured by an upper layer signal, the BS may use the slot format of 255 to allow the UE to determine that the slot format is not valid information. When the BS indicates a slot format corresponding to an error, the BS may indicate through DCI that at least one of the symbols is a DL / UL symbol, which are indicated as UL / DL symbols through SFI information, which is configured through an upper layer signal, or the BS may indicate, for a specific slot, a slot format different from the slot format already indicated through DCI.

[0314] The BS may indicate the slot format only for a slot corresponding to an interval shorter than the interval at which the DCI of the slot format is transmitted. When a value in a reserved slot format value (e.g., R) is used, the value or the slot format may be predefined between the BS and the UE, or may be configured by an upper layer signal. For example, one of the slot formats in 62-254 of Table 3 or one of the R values ​​corresponding thereto may be configured to the UE by an upper layer signal.

[0315] The operation of the UE may be further indicated by using a plurality of reserved values. For example, a first reserved value R1 may be used to indicate to the UE that, in the time slot for which the first reserved value R1 is indicated, UL transmission configured by the upper layer signal is possible. A second reserved value R2 may be used to indicate to the UE that, in the time slot for which the second reserved value R2 is indicated, UL transmission configured by the upper layer signal is not possible.

[0316] As another example, the first (or third) reserved value R1 can be used to indicate to the UE that the cell 2 is performing a channel access procedure in the time slot for which the first (or third) reserved value R1 is indicated. The second (or fourth) reserved value R2 can be used to indicate to the UE that the cell 2 has occupied the channel, but the SFI of the time slot for which the second (or fourth) reserved value R2 is indicated cannot be determined. In this regard, it is possible to define a time slot format corresponding to a reserved value. The reserved value R can be configured as an empty time slot format that does not include time slot format information, can be configured as a specific time slot format mode value (e.g., DUDUDUDU...), or can be configured as a specific value other than a time slot format represented by D / U / F or a non-numerical value.

[0317] With respect to the cell from which SFI information is received via DCI, when the received SFI value is:

[0318] - a slotted format whereby all symbols are represented as flexible symbols,

[0319] - a slot format value of 255 or a specific slot format (e.g., a slot format configured as an empty slot format not including slot format information, a specific slot format mode value (e.g., DUDUDUDU . . . ), or a slot format represented by D / U / F) or a value corresponding thereto,

[0320] - a reserved value or a timeslot format corresponding thereto,

[0321] - a predefined value, a value configured by an upper layer signal, or a corresponding time slot format, or

[0322] -When the slot format corresponds to an error, the UE may discard at least the indicated SFI information from the transmitted cell-related information, may determine that it has failed to determine the DCI, or may determine that the SFI information is not provided. In this regard, the UE may discard not only the SFI information but also the COT information, or may determine that the COT information is not provided.

[0323] The UE may perform a channel access procedure according to the channel access procedure type indicated or configured by the BS, and according to the result thereof, the UE may perform or not perform UL transmission. As described above, the UE may discard the provided SFI information, may determine that the SFI information is not provided or indicated, or may determine that it has failed to determine the DCI, and may perform the following operations for symbols or time slots and symbols or time slots outside the COT.

[0324] - The UE may receive a DL data channel or CSI-RS indicated by another DCI (eg, UL / DL scheduling DCI).

[0325] - The UE may transmit a UL data channel, a UL control channel, a PRACH, or an SRS indicated by another DCI (eg, a UL / DL scheduling DCI or a DCI indicating transmission of an SRS).

[0326] -UE can receive and detect PDCCH through the configured CORESET and control space in the symbol.

[0327] - The UE may not receive the PDSCH or CSI-RS configured to the UE for reception through a higher layer signal.

[0328] -When the UE determines that the SFI information is not provided or indicated by the upper layer signal (e.g., Cat4LBT-Exception), or the UE is configured to be able to send the SRS, PUCCH, PUSCH or PRACH configured by the upper layer information for the UE to send in the symbol for which the DCI for sending the SFI information is not received, the UE may send the SRS, PUCCH, PUSCH or PRACH configured by the upper layer signal for the UE to send in symbol 1185. The UE that is not provided with the upper layer signal (e.g., Cat4LBT-Exception) may not send the SRS, PUCCH, PUSCH or PRACH configured by the upper layer signal for the UE to send.

[0329] Fig.12 is a flowchart illustrating a BS method for configuring or indicating SFI and / or COT information of the BS in a wireless communication system according to an embodiment.

[0330] refer to Fig.12In step 1200 or before step 1200, the BS may determine one or more UL channel access process types used by the UE in the unlicensed band, one or more starting positions for transmitting UL signals or channels, the number of PDSCH / PUSCH or time slots that can be configured through one DCI, a guard interval, etc. based on the capability information of the UE, and may determine the configuration information used by the UE in transmitting UL signals or channels through the unlicensed band in consideration of at least one of the multiple pieces of information, and may configure, provide, or send the configuration information to the UE. When the BS sends information about a cell through DCI to send SFI, an SFI transmission time period, a time / frequency control channel domain in which a DCI format including SFI is sent, and SFI of multiple cells, the BS may perform configuration about a position or a bit area in which the SFI of the corresponding cell is to be sent in the DCI, and may send the configured value to the UE through an upper layer signal. That is, the BS may send configuration information for communicating with the UE.

[0331] In step 1210, when the cell or at least one of the multiple cells that sends SFI via DCI is an unlicensed band cell, the BS may configure the COT field and information related thereto to send to the UE a time period during which the BS occupies a channel in the unlicensed band, for example, an allowable COT set configured to indicate COT to the UE may be configured, and the configured information may be sent to the UE.

[0332] In step 1220, the BS performs a channel access procedure for the unlicensed band cell among the cells.

[0333] In step 1230, before the BS sends the DCI, the BS configures the result of the channel access procedure and the SFI and / or COT information related to the corresponding cell according to various embodiments of the present disclosure, and sends the configuration to the UE through the DCI.

[0334] Fig.13 is a flow chart showing a UE method for determining a time resource allocation region in a wireless communication system according to an embodiment. Specifically, Fig.13 The present invention is a flowchart showing a UE method for determining whether a BS occupies a channel and / or whether a UE is to send an UL signal based on SFI and / or COT information received by the UE in a wireless communication system, and determining at least one of the types of channel access procedures to be performed.

[0335] refer to Fig.13In step 1300 or before, the UE may transmit capability information to the BS, the capability information including one or more UL channel access procedure types for use by the UE in the unlicensed band, one or more starting positions for transmitting UL signals or channels, the number of PDSCH / PUSCH or time slots that can be configured through one DCI, a guard gap, etc. In this regard, without transmitting the capability information including such information, the one or more UL channel access procedure types for use by the UE in the unlicensed band, the one or more starting positions for transmitting UL signals or channels, the number of PDSCH / PUSCH or time slots that can be configured through one DCI, a guard gap, etc. may be predefined. The one or more UL channel access procedure types, the one or more starting positions for transmitting UL signals or channels, the number of PDSCH / PUSCH or time slots that can be configured through one DCI, a gap guard, etc. may be independent according to the unlicensed band frequency or regulations of each country or region. In addition, when the BS transmits information about a cell through DCI to transmit an SFI, an SFI transmission period, a time / frequency control channel field in which a DCI format including an SFI is transmitted, and SFIs of a plurality of cells, the UE receives configuration information about a position or a bit region in which the SFI of the corresponding cell is to be transmitted in the DCI through an upper layer signal, and can perform configuration based on the configuration information. That is, the UE receives configuration information for communicating with the BS.

[0336] In step 1310, the UE receives configuration information for appending COT information to DCI from the BS.

[0337] In step 1320, the UE receives DCI including at least SFI information from the BS, and in step 1330, the UE determines whether the BS occupies a channel in an unlicensed band cell and / or whether the UE is to send a UL signal, and determines at least one of the types of channel access procedures to be performed, by using at least one of the SFI information and / or COT information received through the DCI.

[0338] In the present disclosure, expressions such as “more than (greater than) or equal to” or “less than (less than) or equal to” are used to determine whether a specific condition (or standard) is satisfied, but these expressions do not exclude the meaning of “exceeds” or “less than (less than)”. A condition written with “more than (greater than) or equal to” may be replaced with “exceeds”, a condition written with “less than (less than) or equal to” may be replaced with “less than (less than)”, and a condition written with “more than (greater than) or equal to ... and less than (less than) ...” may be replaced with “exceeds ... and less than (less than) or equal to ...”.

[0339] The methods according to the above embodiments may be implemented by hardware, software, or a combination of hardware and software.

[0340] When these methods are implemented in software, a computer-readable recording medium having one or more programs (software modules) recorded thereon may be provided. One or more programs recorded on the computer-readable recording medium are configured to be executable by one or more processors in an electronic device. One or more programs include instructions for executing methods according to embodiments of the disclosure described in the claims or detailed description.

[0341] The program (e.g., software module or software) may be stored in RAM, nonvolatile memory including flash memory, ROM, electrically erasable programmable read-only memory (EEPROM), magnetic disk storage, CD-ROM, DVD, another type of optical storage device, or cassette tape. 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, each memory may refer to multiple memories.

[0342] The program may also be stored in an attachable storage device that can be accessed via a communication network such as the Internet, an intranet, a local area network (LAN), a WLAN, a storage area network (SAN), or a combination thereof. According to an embodiment of the present disclosure, the storage device may be connected to the apparatus via an external port. Another storage device on the communication network may also be connected to the apparatus for executing an embodiment of the present disclosure.

[0343] According to the above-described embodiments, services can be efficiently provided in a wireless communication system.

[0344] According to an embodiment, the elements included in the present disclosure may be expressed in singular or plural form. However, for ease of explanation, singular or plural form is appropriately selected, and the present disclosure is not limited thereto. In this way, an element expressed in plural form may also be configured as a single element, and an element expressed in singular form may also be configured as multiple elements.

[0345] The above-mentioned embodiments of the present disclosure are merely illustrations of specific examples, in order to facilitate description and understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. It will be appreciated by those skilled in the art that other modifications based on the technical ideas of the present disclosure are feasible. In addition, embodiments 1 to 4 of the present disclosure may be combined with each other. For example, parts of the method provided by the present disclosure may be combined with each other.

[0346] Although the present disclosure has been described in terms of certain embodiments, those skilled in the art will recognize that the embodiments described herein may be practiced with modifications within the spirit and scope of the present disclosure, and that the present disclosure is not limited by the detailed description and embodiments described herein, but by the appended claims and their equivalents.

Claims

1. A method for acquiring time slot format information performed by a user equipment (UE), the method comprising: receiving configuration information about a physical downlink control channel (PDCCH) from a base station (BS); detecting downlink control information (DCI) based on the configuration information; Acquire slot format indicator (SFI) information for at least one slot including a plurality of symbols and information about channel occupancy time (COT) in the DCI; identifying at least one symbol outside the COT among the plurality of symbols based on the information about the COT; discarding the slot format information of the at least one symbol outside the COT, and In the case where the UE is configured by higher layer parameters to send a sounding reference signal (SRS) or a physical random access channel (PRACH) in a symbol for which no DCI for sending SFI information is received, the SRS or PRACH is sent on the at least one symbol outside the COT.

2. The method according to claim 1, wherein: The SFI information indicates the time slot format in units of time slots, and Here, the information on the COT indicates the COT in symbol units. 3 . The method according to claim 1 , wherein the SFI information includes information indicating that a slot or a symbol not included in the COT is a flexible slot or a flexible symbol.

4. A method for providing time slot format information performed by a base station (BS), the method comprising: Sending configuration information about a physical downlink control channel (PDCCH) to a user equipment (UE); transmitting downlink control information (DCI) including slot format indicator (SFI) information for at least one slot including a plurality of symbols and information on a channel occupancy time (COT) to the UE, wherein at least one symbol other than the COT is identified among the plurality of symbols based on information about the COT, The slot format information of the at least one symbol outside the COT is discarded, and In the case where the UE is configured by higher layer parameters to send a sounding reference signal (SRS) or a physical random access channel (PRACH) in a symbol for which no DCI for sending SFI information is received, the SRS or PRACH is sent on the at least one symbol outside the COT.

5. The method according to claim 4, wherein the SFI information indicates a time slot format in units of time slots, and in, The information on the COT field indicates the COT in symbol units.

6. A user equipment (UE), the UE comprising: Transceiver; and The processor is configured as: receiving configuration information about a physical downlink control channel (PDCCH) from a base station (BS); detecting downlink control information (DCI) based on the configuration information; Acquire slot format indicator (SFI) information for at least one slot including a plurality of symbols and information about channel occupancy time (COT) in the DCI; identifying at least one symbol outside the COT among the plurality of symbols based on the information about the COT; discarding the slot format information of the at least one symbol outside the COT, and In the case where the UE is configured by higher layer parameters to send a sounding reference signal (SRS) or a physical random access channel (PRACH) in a symbol for which no DCI for sending SFI information is received, the SRS or PRACH is sent on the at least one symbol outside the COT. 7 . The UE of claim 6 , wherein the processor is further configured to perform a channel access procedure in a time slot or a symbol not included in the COT.

8. The UE of claim 6, wherein the processor is further configured to receive a downlink data channel or a channel state information reference signal (CSI-RS) indicated by a different DCI in a symbol or a time slot not included in the COT.

9. The UE according to claim 6, wherein the SFI information indicates a time slot format in units of time slots, and in, The information on the COT indicates the COT in symbol units. 10 . The UE according to claim 6 , wherein the SFI information includes information indicating that a slot or a symbol not included in the COT is a flexible slot or a flexible symbol.

11. A base station (BS), comprising: Transceiver; and The processor is configured as: Sending configuration information about a physical downlink control channel (PDCCH) to a user equipment (UE); transmitting downlink control information (DCI) including slot format indicator (SFI) information for at least one slot including a plurality of symbols and information on a channel occupancy time (COT) to the UE, wherein at least one symbol other than the COT is identified among the plurality of symbols based on information about the COT, The slot format information of the at least one symbol outside the COT is discarded, and In the case where the UE is configured by higher layer parameters to send a sounding reference signal (SRS) or a physical random access channel (PRACH) in a symbol for which no DCI for sending SFI information is received, the SRS or PRACH is sent on the at least one symbol outside the COT.

12. The BS according to claim 11, wherein the SFI information indicates a slot format in units of slots, and in, The information on the COT field indicates the COT in symbol units.

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