Method and apparatus for determining channel access procedure in a wireless communication system

Abstract

The present invention relates to a method and apparatus for a channel access procedure in a wireless communication system. More specifically, the present invention relates to a method of performing a channel access procedure by a base station in a specific direction (or beam) in an unlicensed band. More specifically, the present invention proposes a method of configuring and generating downlink control information by a base station to transmit a result of performing a channel access procedure in a specific direction to a terminal, and a method of determining information by a terminal. According to an embodiment of the present disclosure, a method for a terminal in a communication system can include the steps of receiving, from a base station, downlink control information (DCI) that schedules uplink signal transmission, checking beam-related information included in the DCI and indicating a beam for transmitting an uplink signal, and performing, based on the beam indicated by the beam-related information, uplink signal transmission to the base station without a channel access procedure by the UE.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for determining a channel access procedure in a wireless communication system. More specifically, the present disclosure relates to a method in a wireless communication system, in particular in an unlicensed frequency band, of including in control information a result of a channel access procedure performed by a system or node transmitting a downlink signal or by a system or node transmitting an uplink signal, transmitting the control information, and determining and interpreting the received control information. BACKGROUND

[0002] To meet the demand for wireless data traffic having increased since the 4G communication system has been commercialized, efforts to develop an enhanced 5G communication system or a pre-5G communication system have been made. For this reason, the 5G communication system or the pre-5G communication system is also called a beyond 4G network communication system or a post LTE system.

[0003] To achieve a data transmission rate, implementation of a 5G communication system in a millimeter wave band (e.g., 60 GHz) is being considered. To reduce a path loss of a radio wave and increase a transfer distance of a radio wave in a millimeter wave band, beamforming, massive MIMO, full dimensional MIMO (FD-MIMO), array antenna, analog beam forming, and large scale antenna techniques have been discussed in the 5G communication system.

[0004] In addition, in the 5G communication system, technologies such as improved small cells, advanced small cells, cloud radio access network (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, moving networks, cooperative communication, coordinated multi-points (CoMP), and reception interference cancellation have been developed to improve the network of the system. In addition, in the 5G communication system, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), which are an advanced coding modulation (ACM) method, and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA), which are an advanced access technology, have been developed.

[0005] Meanwhile, the Internet is evolving from the human-centered connection network where humans generate and consume information to the Internet of Things (IoT) where distributed elements such as things exchange and process information. The Internet of Everything (IoE) that has emerged with the convergence of the IoT technology and the big data processing technology is a concept to connect things, the IoT, to the Internet infrastructure. To implement the IoT, technologies such as a sensing technology, a wired / wireless communication and network infrastructure, a service interface technology, and a security technology are required. Recently, technologies for connection between things, such as a sensor network, machine to machine (M2M), and machine type communication (MTC), have been researched. The IoT environment can provide intelligent Internet technology (IT) services that create a new value for humans by collecting and analyzing data generated among connected things. The IoT can be applied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart home appliance, and advanced medical services through convergence and combination between the existing information technology (IT) and various industrial applications.

[0006] Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as a sensor network, machine to machine (M2M), and machine type communication (MTC) can be implemented by beamforming, MIMO, and array antennas. Application of a cloud RAN as the above-described big data processing technology can also be considered an example of convergence between the 5G technology and the IoT technology. SUMMARY

[0007] [PROBLEMS TO BE SOLVED BY THE INVENTION]

[0008] The present disclosure relates to a method and apparatus for determining a channel access procedure in a wireless communication system. An embodiment of the present disclosure proposes a method of performing and determining a channel access procedure by a system or a node transmitting a downlink signal through an unlicensed band and including a result of the performed and determined channel access procedure in downlink control information. Another embodiment of the present disclosure proposes a method of determining a channel access procedure by a system or a node transmitting an uplink signal based on received downlink control information.

[0009] [TECHNICAL SOLUTION]

[0010] To solve the above-described problem, according to an embodiment of the present disclosure, a method for a terminal in a communication system can include receiving, from a base station, downlink control information (DCI) scheduling uplink signal transmission, identifying beam-related information included in the DCI, the beam-related information indicating a beam for transmitting the uplink signal, and transmitting, to the base station, the uplink signal based on the beam indicated by the beam-related information without a channel access procedure by the UE.

[0011] According to an embodiment of the disclosure, the beam-related information can be determined based on a channel access procedure performed by the base station for each of the at least one beam.

[0012] According to an embodiment of the disclosure, the channel access procedure performed by the base station for each of the at least one beam can be performed based on an arbitrary integer value selected for each of the at least one beam within a contention window.

[0013] According to an embodiment of the disclosure, in the case where the beam-related information is not included in the DCI, the uplink signal can be transmitted to the base station based on a channel access procedure performed by the UE.

[0014] According to an embodiment of the disclosure, a method of a base station in a communication system can include identifying beam-related information indicating a beam for transmitting an uplink signal of a user equipment (UE), transmitting, to the UE, a downlink control information (DCI) including the beam-related information and scheduling the uplink signal transmission, and receiving the transmitted uplink signal from the UE based on the beam indicated by the beam-related information without a channel access procedure by the UE.

[0015] According to an embodiment of the disclosure, a user equipment (UE) in a communication system can include a transceiver unit and a controller. The controller is configured to receive, from a base station, a downlink control information (DCI) scheduling an uplink signal transmission, identify beam-related information included in the DCI, the beam-related information indicating a beam for transmitting the uplink signal, and transmit, to the base station, the uplink signal based on the beam indicated by the beam-related information without a channel access procedure by the UE.

[0016] According to an embodiment of the disclosure, a base station in a communication system can include a transceiver unit and a controller. The controller is configured to identify beam-related information indicating a beam for transmitting an uplink signal of a user equipment (UE), transmit, to the UE, a downlink control information (DCI) including the beam-related information and scheduling the uplink signal transmission, and receive the transmitted uplink signal from the UE based on the beam indicated by the beam-related information without a channel access procedure by the UE.

[0017] [Advantageous Effects]

[0018] According to an embodiment of the disclosure, in a wireless communication system, a method of determining control information included in a downlink control channel by a system or a node receiving a downlink signal or a system or a node transmitting an uplink signal can improve uplink data transmission efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain, i.e., a wireless resource domain in which data or a control channel is transmitted in an uplink / downlink of an NR system or a similar system, according to an embodiment of the disclosure.

[0020] Figure 2 FIG. 2 is a diagram illustrating an example in which a terminal bandwidth has been configured as two bandwidth parts (BWPs) according to an embodiment of the disclosure.

[0021] Figure 3 FIG. 3 is a diagram illustrating an embodiment of a control resource set (CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system according to an embodiment of the disclosure.

[0022] Figure 4 FIG. 4 is a diagram describing a structure of a downlink control channel in a wireless communication system according to an embodiment of the disclosure.

[0023] Figure 5 FIG. 5 is a diagram illustrating a resource domain in which a data channel is transmitted in a 5G communication system according to an embodiment of the disclosure.

[0024] Figure 6 FIG. 6 is a diagram illustrating a procedure of configuring and activating a PDCCH beam according to an embodiment of the disclosure.

[0025] Figure 7 FIG. 7 is a diagram illustrating a procedure of configuring and activating a PDSCH beam according to an embodiment of the disclosure.

[0026] Figure 8 FIG. 8 is a diagram illustrating an example of a PDSCH basic beam operation according to an embodiment of the disclosure.

[0027] Figure 9 FIG. 9 is a diagram illustrating a scenario in which an uplink signal is transmitted in an unlicensed band without uplink scheduling information according to an embodiment of the disclosure.

[0028] Figure 10 FIG. 10 is a diagram illustrating an example of a method of determining a contention window (CW_p) according to an embodiment of the disclosure.

[0029] Figure 11 FIG. 11 is a diagram illustrating a method of performing a channel access procedure by a base station and a terminal according to an embodiment of the disclosure.

[0030] Figure 12a FIG. 12 is a diagram illustrating a method of performing a channel access procedure by a base station and a terminal according to an embodiment of the disclosure.

[0031] Figure 12bis a diagram illustrating a method of performing a channel access procedure by a base station and a terminal according to another embodiment of the disclosure.

[0032] Figure 13 is a diagram illustrating an operation of a base station according to an embodiment of the disclosure.

[0033] Figure 14 is a diagram illustrating an operation of a terminal according to an embodiment of the disclosure.

[0034] Figure 15 is a block diagram illustrating a structure of a base station according to an embodiment of the disclosure.

[0035] Figure 16 is a block diagram illustrating a structure of a terminal according to an embodiment of the disclosure. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings. In addition, in describing the disclosure, when it is considered that a detailed description of related known functions or configurations will unnecessarily obscure the subject matter of the disclosure, a detailed description thereof will be omitted. Furthermore, the terms to be described hereinafter have been defined in consideration of the functions in the disclosure, and can vary according to the intention of users, operators, or practices. Therefore, each term should be defined based on the contents throughout the specification.

[0037] The advantages and features of the disclosure and methods for achieving the advantages and features will become apparent by referring to the embodiments described below in detail in connection with the accompanying drawings. However, the disclosure is not limited to the disclosed embodiments but can be implemented in various different forms. These embodiments are provided only to complete the disclosure and to fully convey the scope of the disclosure to those skilled in the art to which the disclosure pertains. The disclosure is defined by the scope of the claims. Throughout the specification, like reference numerals denote like elements.

[0038] Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings.

[0039] In describing the embodiments, a description of technical contents well known in the art to which the disclosure belongs and not directly related to the disclosure is omitted to clearly convey the subject matter of the disclosure without obscuring the subject matter of the disclosure by omitting unnecessary descriptions.

[0040] For the same reason, in the drawings, some elements are enlarged, omitted, or schematically shown. In addition, the size of each element cannot accurately reflect its actual size. In the drawings, the same or similar elements are assigned the same reference numerals.

[0041] The advantages and features of the present disclosure and methods for accomplishing the same will become apparent from the following embodiments described in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the disclosed embodiments but can be implemented in various different forms. These embodiments are provided merely to complete the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. The present disclosure is defined by the scope of the claims. Throughout the specification, like drawing reference numerals denote like elements.

[0042] In the present disclosure, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These computer program instructions can be loaded onto a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute on the computer or other programmable data processing apparatus, generate means for implementing the functions specified in the flowchart block or blocks. These computer program instructions can also be stored in a computer usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instructions that implement the function specified in the flowchart block or blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable data processing apparatus to produce a computer implemented process such that the instructions that execute on the computer or other programmable data processing apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0043] Furthermore, each block of the flowchart illustrations can represent a portion of a module, segment, or code including one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order. For example, two blocks shown in succession can in fact be executed substantially concurrently or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved.

[0044] In this case, the term "unit" used in the present embodiment indicates a software or hardware component such as an FPGA or an ASIC, and the "unit" performs a specific task. However, the term "unit" is not limited to software or hardware. The "unit" can be advantageously configured to reside in an addressable storage medium and configured to operate on one or more processors. Thus, the "unit" can include, for example, components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in components and "units" can be combined into fewer components and "units", or further divided into additional components and "units". Furthermore, components and "units" can be implemented as one or more CPUs in a device or a secure multimedia card. Furthermore, in an embodiment, the "unit" can include one or more processors.

[0045] Compared to the existing 4G system, support for each service is considered in the 5G system. For example, the most representative services can include enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), massive machine type communication (mMTC), evolved multimedia broadcast / multicast service (eMBMS), etc. In addition, a system providing a URLLC service can be referred to as a URLLC system, a system providing an eMBB service can be referred to as an eMBB system, etc. In addition, the terms "service" and "system" can be used interchangeably.

[0046] As described above, in a communication system, a plurality of services can be provided to a user. In order to provide a user with a plurality of such services, a method capable of providing each service in the same time interval according to the characteristics of each service and an apparatus using the same are required.

[0047] Meanwhile, in a wireless communication system such as an LTE or LTE-A system or a 5G new radio (NR) system, a base station can configure a terminal by transmitting downlink control information (DCI) including resource allocation information, in which a downlink signal transmitted to the terminal is transmitted through a physical downlink control channel (PDCCH) such that the terminal receives at least one of downlink control information (e.g., a channel state-information reference signal (CSI-RS), a physical broadcast channel (PBCH), or a physical downlink shared channel (PDSCH)). For example, the base station transmits DCI indicating that the terminal needs to receive a PDSCH through a PDCCH in subframe n to the terminal in subframe n. The terminal that receives the DCI receives the PDSCH in subframe n based on the received downlink control information. Further, in an LTE or LTE-A or NR system, a base station can configure a terminal by transmitting DCI including uplink resource allocation information through a PDCCH to the terminal such that the terminal transmits at least one of uplink control information (e.g., a sounding reference signal (SRS) or uplink control information (UCI), or a physical random access channel (PRACH), or a physical uplink shared channel (PUSCH)) to the base station. For example, a terminal that has received uplink transmission configuration information (or uplink DCI or a UL grant) transmitted by the base station through a PDCCH in subframe n can perform transmission of a PUSCH (hereinafter, referred to as PUSCH transmission) based on a predetermined time (e.g., n+4), a time configured by a higher layer signal (e.g., n+k), or uplink signal transmission time indicator information N+k included in the uplink transmission configuration information.

[0048] If the configured downlink transmission is transmitted from the base station to the terminal through the unlicensed band, or the configured uplink transmission is transmitted from the terminal to the base station through the unlicensed band, the transmitting apparatus (the base station or the terminal) can perform a channel access procedure (or listen before talk (LBT)) on the unlicensed band, in which the signal transmission in the unlicensed band has been configured before or just before the start timing of the configured signal transmission. If it is determined that the unlicensed band is in an idle state based on the result of the execution of the channel access procedure, the transmitting apparatus can access the unlicensed band and perform the configured signal transmission. If it is determined that the unlicensed band is not in an idle state or is in an occupied state based on the channel access procedure performed by the transmitting apparatus, the transmitting apparatus does not perform the transmission of the configured signal because the transmitting apparatus does not access the unlicensed band. In general, in the channel access procedure in the unlicensed band in which the signal transmission has been configured, the transmitting apparatus can receive a signal in the unlicensed band for a given time or a time calculated according to a predetermined rule (for example, a time calculated from at least one random value selected by the base station or the terminal), and can determine the idle state of the unlicensed band by comparing the strength of the received signal with a threshold value defined in advance or a threshold value calculated by a function composed of at least one variable (channel bandwidth, bandwidth of a signal to be transmitted, strength of transmission power, beamwidth of a transmitted signal, etc.). For example, if the strength of the received signal for 25 μs is less than a predetermined threshold value -72 dBm, the transmitting apparatus can determine that the unlicensed band is in an idle state, and can perform the configured signal transmission. In this case, according to the maximum channel occupancy time in the unlicensed band defined for each country or region or the type of the transmitting apparatus (for example, a base station, a terminal, a master apparatus, or a slave apparatus), the maximum time that can be used for signal transmission can be limited. For example, in the 5 GHz unlicensed band in Japan, the base station or the terminal can perform the channel access procedure and then can transmit a signal by occupying the channel without performing an additional channel access procedure for a long time of 4 ms. If the strength of the received signal for 25 μs is greater than the predetermined threshold value -72 dBm, the base station can determine that the unlicensed band is not in an idle state, and does not transmit a signal.

[0049] In the case of the 5G communication system, in order to provide various services and support a high data transmission rate, various technologies have been introduced, such as retransmission in a code block unit and a technology capable of transmitting an uplink signal without uplink scheduling information. Therefore, if 5G communication is to be performed through an unlicensed band, a more efficient channel access procedure considering various variables is required.

[0050] Wireless communication systems have evolved from providing voice-based services in the early stage to broadband wireless communication systems providing high-speed and high-quality packet data services, for example, communication standards such as 3GPP's High Speed Packet Access (HSPA), Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), 3GPP2's High Rate Packet Data (HRPD), Ultra Mobile Broadband (UMB), and IEEE 802.16e, etc. In addition, a communication standard of 5G or New Radio (NR) as a 5G wireless communication system.

[0051] As described above, in a wireless communication system including 5G, at least one service of enhanced mobile broadband (eMBB), massive machine type communications (mMTC), or ultra-reliable and low-latency communications (URLLC) can be provided to a terminal. These services can be provided to the same terminal at the same time interval. In the present embodiment, eMBB, mMTC, or URLLC can be a service for high-speed transmission of a large amount of data, a service for minimizing terminal power and multiple terminal access, and a service for high reliability and low latency, respectively, but the present disclosure is not limited thereto. The three services can be major scenarios in an LTE system or a 5G / NR (New Radio, Next Radio) system such as post-LTE.

[0052] When a base station schedules data corresponding to an eMBB service for a terminal at a specific transmission time interval (TTI), if a case where URLLC data must be transmitted occurs in the TTI, some eMBB data can not be transmitted in a frequency band in which the eMBB data has been scheduled to be transmitted, and generated URLLC data can be transmitted in the frequency band. The terminal scheduled by the eMBB and the terminal scheduled by the URLLC can be the same terminal or different terminals. In this case, since some eMBB data that has been scheduled to be transmitted does not exist, a probability that the eMBB data can be damaged is increased. Therefore, in this case, a method of processing signals received by a terminal scheduled with eMBB and a terminal scheduled with URLLC and a method of receiving the signals are required.

[0053] Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. In addition, the terms to be described below have been defined by considering their functions in the present disclosure, and can vary according to the intention of a user or an operator or practice. Therefore, the terms should be defined based on the entire content of the specification. Hereinafter, a base station is a subject that performs resource allocation for a terminal, and can be an eNode B, a Node B, a base station (BS), a radio access unit. The base station controls at least one of a base station controller or a node in a network. The terminal can include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, a downlink (DL) denotes a wireless transmission path through which a base station transmits a signal to a terminal, and an uplink (UL) denotes a wireless transmission path through which a terminal transmits a signal to a base station. In addition, hereinafter, embodiments of the present disclosure are described as an example of an LTE or LTE-A system, but the embodiments of the present disclosure are also applied to other communication systems having a similar technical background or channel form. For example, the other communication systems can be included in 5G mobile communication technology (5G, new radio (NR)) developed after LTE-A. In addition, based on the determination of those skilled in the art, the embodiments of the present disclosure can also be applied to other communication systems by making some modifications to the embodiments without significantly deviating from the scope of the present disclosure.

[0054] As a representative example of a wideband wireless communication system, in an NR system, an orthogonal frequency division multiplexing (OFDM) method is employed in a downlink (DL), and an OFDM and a single carrier frequency division multiple access (SC-FDMA) method are employed in an uplink (UL). The uplink refers to a radio link through which a terminal (or UE) or a mobile station (MS) transmits data or a control signal to an eNode B (or a base station (BS)). The downlink refers to a radio link through which a base station transmits data or a control signal to a terminal. In such a multiple access method, data or control information of a user can be distinguished by allocating and operating time-frequency resources that will carry and transmit data or control information such that the time-frequency resources for each user do not overlap, that is, orthogonality between time-frequency resources is established.

[0055] In a 5G system, it is necessary to flexibly define and operate a frame structure by considering various services and requirements. For example, it can be considered that each service has a different subcarrier spacing according to a need. In the current 5G communication system, a method of supporting a plurality of subcarrier spacings can be determined by using the following [Equation 1].

[0056] [Equation 1]

[0057] Δf = f02 m

[0058] where f0 denotes a base subcarrier spacing of the system, and m denotes an adjustment factor of an integer. For example, if f0 is 15 kHz, a set of subcarrier spacings that can be provided to a 5G communication system can include 3.75 kHz, 7.5 kHz, 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, 480 kHz, etc. The set of available subcarrier spacings can be different according to a frequency band. For example, 3.75 kHz, 7.5 kHz, 15 kHz, 30 kHz, and 60 kHz can be used in a 6 GHz or lower frequency band, and 60 kHz, 120 kHz, and 240 kHz can be used in a frequency band greater than 6 GHz.

[0059] The length of a corresponding OFDM symbol can be different according to a subcarrier spacing constituting the OFDM symbol. This is a characteristic of the OFDM symbol, and the reason for this is that the subcarrier spacing and the length of the OFDM symbol have an inverse relationship. For example, if the subcarrier spacing is doubled, the symbol length is halved. Conversely, if the subcarrier spacing is halved, the symbol length is doubled.

[0060] The NR system adopts a hybrid automatic repeat request (HARQ) method of retransmitting corresponding data in a physical layer when a decoding failure occurs in initial transmission. The HARQ method enables a receiver to transmit information (negative acknowledgement (NACK)) informing a transmitter of a decoding failure, so that the transmitter can retransmit data in a physical layer when the receiver cannot accurately decode the corresponding data. The receiver improves data reception performance by combining data retransmitted by the transmitter with data that has previously failed to be decoded. In addition, the HARQ method enables the receiver to transmit information (positive acknowledgement (ACK)) informing the transmitter of decoding success to the transmitter, so that the transmitter can transmit new data if the receiver has accurately decoded the data.

[0061] Figure 1 is a diagram illustrating a basic structure of a time-frequency domain, that is, a wireless resource domain in which data or a control channel is transmitted in an uplink / downlink of an NR system or a system similar thereto.

[0062] Referring to Figure 1 , the horizontal axis denotes a time domain, and the vertical axis denotes a frequency domain. The smallest transmission unit in the time domain is an OFDM or DFT-s-OFDM symbol. N symbOne OFDM or DFT-s-OFDM symbol 101 constitutes one slot 102. In this case, the OFDM symbol is a symbol in case of transmitting and receiving a signal by using an OFDM multiplexing method. The DFT-s-OFDM symbol denotes a symbol in case of transmitting and receiving a signal by using a DFT-s-OFDM or SC-FDMA multiplexing method. Hereinafter, for convenience of description, in the disclosure, the OFDM symbol and the DFT-s-OFDM symbol are generally described as the OFDM symbol without distinguishing the OFDM symbol and the DFT-s-OFDM symbol, and will be described based on transmission and reception of a downlink signal, but it is also applicable to transmission and reception of an uplink signal.

[0063] If the interval between subcarriers is 15 kHz, one slot constitutes one subframe 103, and the length of each slot and subframe is 1 ms. In this case, the number of slots constituting one subframe 103 and the length of the slot can be different according to the interval between subcarriers. For example, if the interval between subcarriers is 30 kHz, four slots can constitute one subframe 103. In this case, the length of the slot is 0.5 ms, and the length of the subframe is 1 ms. Further, a radio frame 104 is a time interval consisting of 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier. The bandwidth of the entire system transmission bandwidth is constituted by a total of N BW subcarriers (105). However, such detailed numerical values can be variably applied. For example, in the case of the LTE system, the interval between subcarriers is 15 kHz, but two slots constitute one subframe 103. In this case, the length of the slot is 0.5 ms, and the length of the subframe is 1 ms.

[0064] In the time-frequency domain, the basic unit of a resource is a resource element (RE) 106, and can be indicated as an OFDM symbol index and a subcarrier index. A resource block (RB) 107 or a physical resource block (PRB) can be defined as N symb consecutive OFDM symbols (101) in the time domain and N sc RB consecutive subcarriers (108) in the frequency domain. Accordingly, in one slot, one RB 107 can include N symb ×N sc RB REs. Generally, the minimum allocation unit of data in the frequency domain is the RB 107. Generally, in the NR system, N symb = 14, N sc RB = 12, the number of RBs (N RB ) can vary according to the bandwidth of the system transmission band. Generally, in the LTE system, N symb= 7, N sc RB = 12, and N RB The number of RBs can vary according to the bandwidth of a system transmission band.

[0065] Downlink control information can be transmitted within the first N OFDM symbols in a subframe. Generally, N can be {1, 2, 3}. A terminal can be configured with the number of symbols in which downlink control information can be transmitted by a higher layer signal from a base station. In addition, the base station can change the number of symbols in which downlink control information can be transmitted in a current slot for each slot according to the amount of control information to be transmitted in the slot, and can transmit information about the number of symbols to the terminal through a separate PDCCH.

[0066] In NR, one component carrier (CC) or serving cell can be composed of a maximum of 250 RBs or more. Therefore, if a terminal always receives the entire bandwidth of a serving cell in LTE, the power consumption of the terminal can be severe. To solve this problem, a base station can support configuring one or more bandwidth parts (BWPs) for a terminal so that the terminal can change the reception domain within a cell. In NR, the base station can configure an "initial BWP" for a terminal through a master information block (MIB), that is, the bandwidth of CORESET #0 (or common search space (CSS)). Thereafter, the base station can configure the first BWP of the terminal through RRC signaling, and can notify at least one BWP configuration information that can be indicated through downlink control information (DCI) in the future. Thereafter, the base station can notify the terminal of a BWP ID through DCI to indicate which frequency band the terminal will use. If the terminal does not receive DCI in the currently allocated BWP for a certain time or longer, the terminal returns to the "default BWP" and attempts to receive DCI.

[0067] Reference Figure 2 , Figure 2 An example in which a UE bandwidth 2-00 is composed of two BWPs, that is, BWP #1 (2-05) and BWP #2 (2-10), is shown. A base station can configure one or more BWPs for a UE, and can configure information about each BWP, for example, the following [Table 1].

[0068] [Table 1]

[0069]

[0070] The disclosure is not limited to the above-described embodiments. In addition to the above-described configuration information, various parameters related to the BWP can be configured for the UE. The base station can transmit the above-described information to the UE through higher layer signaling (e.g., RRC signaling). At least one of the configured one or more BWPs can be activated. Whether the configured BWP is activated can be semi-statically transmitted through RRC signaling, or can be dynamically transmitted to the UE from the base station through a MAC control element (CE) or DCI.

[0071] According to an embodiment, before performing a radio resource control (RRC) connection, the UE can be configured with an initial BWP for initial access from the base station through a master information block (MIB). More specifically, the UE can receive configuration information for a control resource set (CORESET) and a search space in which a PDCCH can be transmitted to receive system information necessary for initial access in an initial access step through the MIB, the system information can correspond to remaining system information (RMSI) or system information block 1 (SIB1). Each of the CORESET and the search space configured through the MIB can be considered to be identified (ID) as 0.

[0072] The base station can inform the UE of frequency allocation information, time allocation information, configuration information such as a number theory for the CORESET#0 through the MIB. In addition, the base station can inform the UE of configuration information for a monitoring period and occasion of the CORESET#0, that is, configuration information for the search space#0 through the MIB. The UE can consider a frequency domain of the CORESET#0 configured from the MIB as an initial BWP for initial access. In this case, the ID of the initial BWP can be considered to be 0.

[0073] In a method of configuring the above-described BWP, before the RRC connection, the UE can receive configuration information of the initial BWP through the MIB in an initial access step. More specifically, the UE can be configured to have a control resource set (or CORESET) for a PDCCH, in which DCI scheduling a system information block (SIB) can be transmitted from a MIB of a physical broadcast channel (PBCH). The bandwidth of the CORESET configured through the MIB can be considered to be an initial BWP. The UE can receive a PDSCH transmitting the SIB through the configured initial BWP. In addition to the reception of the SIB, the initial BWP can be used for other system information (OSI), paging, and random access.

[0074] Hereinafter, a synchronization signal / PBCH block (SSB) of a next-generation mobile communication system (5G or NR system) is described.

[0075] The SS / PBCH block can refer to a physical layer channel block consisting of a primary SS (PSS), a secondary SS (SSS), and a PBCH. More specifically, the SS / PBCH block can be defined as follows.

[0076] - PSS: This is a signal, i.e., a reference for downlink time / frequency synchronization, and can provide some information of a cell ID.

[0077] - SSS: This is a reference for downlink time / frequency synchronization, and can provide the remaining cell ID information not provided by the PSS. In addition, the SSS can serve as a reference signal for PBCH demodulation.

[0078] - PBCH: This can provide basic system information necessary for a data channel and a control channel of a transmitting and receiving UE. The basic system information can include search space related control information indicating radio resource mapping information of a control channel, control information scheduling a separate data channel transmitting system information, etc.

[0079] - SS / PBCH block: The SS / PBCH block can be composed of a combination of the PSS, the SSS, and the PBCH. One or more SS / PBCH blocks can be transmitted within a time of 5 ms. Each SS / PBCH block transmitted can be distinguished based on an index.

[0080] The UE can detect the PSS and the SSS in an initial access step, and can decode the PBCH. The UE can obtain the MIB from the PBCH, and can be configured with CORESET#0 through the MIB. Assuming that a demodulation reference signal (DMRS) transmitted in a selected SS / PBCH block has been QCLed with CORESET#0, the UE can perform monitoring on CORESET#0. The UE can receive system information as downlink control information transmitted in control resource set#0. The UE can obtain configuration information related to a random access channel (RACH) necessary for initial access from the received system information. The UE can transmit a physical RACH (PRACH) to a base station in consideration of a selected SS / PBCH index. The base station that has received the PRACH can obtain information about the SS / PBCH block index selected by the UE. The base station can know which block of the SS / PBCH block the UE has selected, and the UE monitors CORESET#0 corresponding to (or associated with) the selected SS / PBCH block.

[0081] Hereinafter, downlink control information (hereinafter, DCI) in a next-generation mobile communication system (5G or NR system) is specifically described.

[0082] In a next generation mobile communication system (5G or NR system), scheduling information on uplink data (or PUSCH) or downlink data (or PDSCH) can be transmitted from a base station to a UE through DCI. The UE can monitor a DCI format for fallback and a DCI format for non-fallback with respect to the PUSCH or the PDSCH. The DCI format for fallback can be composed of a fixed field that is predefined between the base station and the UE. The DCI format for non-fallback can include a configurable field.

[0083] The DCI can be transmitted through a physical downlink control channel (PDCCH), i.e., a PDCCH via a channel coding and modulation process. A cyclic redundancy check (CRC) can be attached to a payload of the DCI message. The CRC can be scrambled by a radio network temporary identifier (RNTI) corresponding to an identity of the UE. Different RNTIs can be used to scramble the CRC attached to the payload of the DCI message according to a purpose of the DCI message (e.g., UE-specific data transmission, a power control command, or a random access response). That is, the RNTI is not explicitly transmitted but can be included in a CRC calculation process and transmitted. When the DCI message transmitted on the PDCCH is received, the UE can verify the CRC by using the allocated RNTI. If the CRC verification result is correct, the UE can know that the corresponding message has been transmitted to the UE.

[0084] For example, the DCI scheduling a PDSCH for system information (SI) can be scrambled by an SI-RNTI. The DCI scheduling a PDSCH for a random access response (RAR) message can be scrambled by an RA-RNTI. The DCI scheduling a PDSCH for a paging message can be scrambled by a P-RNTI. The DCI providing a slot format indicator (SFI) notification can be scrambled by an SFI-RNTI. The DCI providing a power control (TPC) notification transmission can be scrambled by a TPC-RNTI. The DCI for scheduling a UE-specific PDSCH or PUSCH can be scrambled by a cell RNTI (C-RNTI).

[0085] The DCI format 0_0 can be used as fallback DCI for scheduling the PUSCH. In this case, the CRC can be scrambled by the C-RNTI. In an embodiment, the DCI format 0_0 having the CRC scrambled by the C-RNTI can include information such as the following [Table 2].

[0086] [Table 2]

[0087]

[0088]

[0089] The DCI format 0_1 can be used as non-fallback DCI scheduling PUSCH. In this case, the CRC can be scrambled by C-RNTI. In an embodiment, the DCI format 0_1 scrambled by C-RNTI can include information such as the following [Table 3].

[0090] [Table 3]

[0091]

[0092]

[0093] The DCI format 1_0 can be used as fallback DCI scheduling PDSCH. In this case, the CRC can be scrambled by C-RNTI. In an embodiment, the DCI format 1_0 scrambled by C-RNTI can include information such as the following [Table 4].

[0094] [Table 4]

[0095]

[0096]

[0097] Alternatively, the DCI format 1_0 can be used as DCI scheduling PDSCH for a RAR message. In this case, the CRC can be scrambled by RA-RNTI. The DCI format 1_0 scrambled by C-RNTI can include information shown in Table 5 below.

[0098] [Table 5]

[0099]

[0100] The DCI format 1_1 can be used as non-fallback DCI scheduling PDSCH. In this case, the CRC can be scrambled by C-RNTI. In an embodiment, the DCI format 1_1 scrambled by C-RNTI can include information shown in Table 6 below.

[0101] [Table 6]

[0102]

[0103]

[0104] Figure 3 FIG. 1 is a diagram illustrating an embodiment of a control resource set (CORESET) in which a PDCCH is transmitted in a 5G wireless communication system according to an embodiment of the disclosure.

[0105] Referring to Figure 3 , Figure 3An embodiment in which a UE bandwidth part 3-10 in a frequency domain and two CORESETs (CORESET #1 (3-01) and CORESET #2 (3-02)) within one slot 3-20 in a time domain are configured is shown. The CORESETs 3-01 and 3-02 can be configured in a specific frequency resource 3-03 within the entire UE bandwidth part 3-10 in the frequency domain. The CORESETs 3-01 and 3-02 can be configured as one or more OFDM symbols in the time domain. This can be defined as a CORESET duration 3-03. Referring to Figure 3 , the CORESET #1 (3-01) can be configured as a CORESET duration of two symbols. The CORESET #2 (3-02) can be configured as a CORESET duration of one symbol.

[0106] The aforementioned CORESET in the next generation mobile communication system (5G or NR system) can be configured to the UE by the base station through higher layer signaling (e.g., system information, master information block (MIB), or radio resource control (RRC) signaling). The configuration of the CORESET to the UE means to provide the UE with information such as a CORESET identification, a frequency location of the CORESET, or a symbol length of the CORESET. For example, the configuration of the CORESET can include information such as the following [Table 7].

[0107] [Table 7]

[0108]

[0109]

[0110] In [Table 7], the tCI-StatesPDCCH (hereinafter referred to as "TCI state") configuration information can include information of one or more synchronization signal (SS) / physical broadcast channel (PBCH) block indices or channel state information reference signal (CSI-RS) indices having a quasi co-location (QCL) relationship with a demodulation reference signal (DMRS) transmitted in the corresponding CORESET. In addition, the frequency domain resource configuration information configures the frequency resources of the corresponding CORESET in the form of a bitmap. In this case, each bit indicates a group of six non-overlapping PRBs bundled. The first group indicates six PRB groups having first PRB indices In this case, indicates the start of the BWP. The most significant bit of the bitmap indicates the first group and is configured in ascending order.

[0111] In a wireless communication system, one or more different antenna ports (or alternatively one or more channels, signals, and combinations thereof, but for ease of description in the future disclosure to be published, are uniformly expressed as "different antenna ports" which can be associated by QCL configuration such as the following [Table 8].

[0112] [Table 8]

[0113]

[0114]

[0115] Specifically, the QCL configuration can associate two different antenna ports as a relationship between a target antenna port (of QCL) and a reference antenna port (of QCL). Upon reception through the target antenna port, the terminal can apply (or assume) some or all channel statistical characteristics (e.g., large-scale parameters of a channel such as Doppler shift, Doppler spread, average delay, delay spread, average gain, and spatial Rx (or Tx) parameters, reception spatial filtering coefficients or transmission spatial filtering coefficients of the terminal) measured at the reference antenna port. The target antenna port indicates an antenna port that transmits a channel or a signal configured by a higher layer including the QCL configuration, and an antenna port that transmits a channel or a signal to which a TCI state indicating the QCL configuration is applied. The reference antenna port indicates an antenna port that transmits a channel or a signal indicated (specified) by the parameter "referenceSignal" within the QCL configuration.

[0116] Specifically, the channel statistical characteristics (indicated by the parameter qcl-Type within the QCL configuration) defined by the QCL configuration can be classified according to the QCL type as follows.

[0117] "QCL-Type A": {Doppler shift, Doppler spread, average delay, delay spread}

[0118] "QCL-Type B": {Doppler shift, Doppler spread}

[0119] "QCL-Type C": {Doppler shift, average delay}

[0120] "QCL-Type D": {spatial Rx parameters}

[0121] In this case, the kind of QCL Type is not limited to the above four, but in order to avoid confusion in describing the subject matter, all possible combinations thereof are not listed. In the above description, since QCL-Type A is a QCL Type used when all statistical characteristics measurable on the frequency axis and the time axis are referable, since the bandwidth and the transmission interval of the target antenna port are sufficient compared to the reference antenna port (i.e., when the number of samples and the transmission frequency band / time of the target antenna port are both greater than those of the reference antenna port in both the frequency domain and the time domain). QCL-Type B is a QCL Type used when the bandwidth of the target antenna port is sufficient to measure the statistical characteristics (i.e., Doppler shift and Doppler spread) measurable in the frequency domain. QCL-Type C is a QCL Type used only when the first-order statistics (i.e., only the Doppler shift and the average delay) are referable, since the bandwidth and the transmission interval of the target antenna port are not sufficient to measure the second-order statistics (i.e., the Doppler spread and the delay spread). QCL-Type D is a QCL Type configured when the spatial reception filter value used when receiving the reference antenna port can be used to receive the target antenna port.

[0122] Meanwhile, the base station can configure up to two QCL configurations for one target antenna port through the TCI state configuration, such as the following [Table 9a].

[0123] [Table 9a]

[0124]

[0125] The first QCL configuration among the two QCL configurations included in one TCI state configuration can be configured as one of QCL-Type A, QCL-Type B, or QCL-Type C. In this case, the configurable QCL Type is designated according to the type of the target antenna port and the reference antenna port, which is described in detail below. In addition, the second QCL configuration among the two QCL configurations included in one TCI state configuration can be configured as QCL-Type D, and in some cases can be omitted.

[0126] The following Tables 9ba to 9be are tables representing valid TCI state configurations according to the type of the target antenna port.

[0127] Table 9ba shows valid TCI state configurations when the target antenna port is a CSI-RS for tracking (TRS). TRS denotes a NZP CSI-RS in which the repetition parameter is not configured and "trs-Info" is configured to true. Configuration 3 in Table 9ba can be used for aperiodic TRS.

[0128] Table 9ba Effective TCI state configuration when target antenna port is CSI-RS for tracking (TRS).

[0129] [table 9ba]

[0130] Effective TCI state configuration when target antenna port is CSI-RS for tracking (TRS)

[0131]

[0132] Table 9bb shows effective TCI state configuration when target antenna port is CSI-RS for CSI. CSI-RS for CSI means NZP CSI-RS in which repetition parameter is not configured and “trs-Info” is not configured to be true.

[0133] [table 9bb]

[0134] Effective TCI state configuration when target antenna port is CSI-RS for CSI

[0135]

[0136] Table 9bc shows effective TCI state configuration when target antenna port is CSI-RS for beam management (BM) (same meaning as CSI-RS for L1 RSRP reporting). CSI-RS for BM means NZP CSI-RS in which repetition parameter with enable or disable value is configured and “trs-Info” is not configured to be true.

[0137] [table 9bc]

[0138] Effective TCI state configuration when target antenna port is CSI-RS for BM (for L1 RSRP reporting)

[0139]

[0140] Table 9bd shows effective TCI state configuration when target antenna port is PDCCH DMRS.

[0141] [table 9bd]

[0142] Effective TCI state configuration when target antenna port is PDCCH DMRS

[0143] Table 9be shows effective TCI state configuration in case that target antenna port is PDSCH DMRS.

[0144] [table 9be]

[0145] When the target antenna port is PDSCH DMRS in case of effective TCI state configuration

[0146]

[0147] The representative QCL configuration method according to Table 9ba to Table 9be is to configure and operate the target antenna port and the reference antenna port for each step, like “SSB” > “TRS” > “CSI-RS for CSI, or CSI-RS for BM, or PDCCH DMRS, or PDSCH DMRS”. Thus, it is possible to help the terminal perform reception operation by associating statistical properties that can be measured from the SSB and the TRS with each antenna port.

[0148] Figure 4 is a diagram describing a structure of a PDCCH in a wireless communication system according to an embodiment of the disclosure. That is, Figure 4 is a diagram illustrating an example of a basic unit constituting a time-frequency resource of a PDCCH that can be used in 5G according to an embodiment of the disclosure.

[0149] Referring to Figure 4 , a basic unit constituting a time-frequency resource of a control channel can be defined as a resource element group (REG) 403. The REG 403 can be defined as 1 OFDM symbol 401 in a time domain and 1 physical resource block (PRB) 402, i.e., 12 subcarriers, in a frequency domain. The base station can constitute a PDCCH allocation unit by connecting the REGs 403.

[0150] As shown in Figure 4 , if a basic unit allocated to the PDCCH in 5G is a control channel element (CCE) 404, 1 CCE 404 can be constituted by a plurality of REGs 403. For example, Figure 4 As shown in , the REG 403 can be constituted by 12 REs. If 1 CCE 404 is constituted by 6 REGs 403, 1 CCE 404 can be constituted by 72 REs. If a downlink CORESET is configured, the corresponding CORESET can be constituted by a plurality of CCEs 404. A specific PDCCH can be transmitted by being mapped to one or more CCEs 404 according to an aggregation level (AL) within the CORESET. The CCEs 404 within the CORESET are distinguished by numbers. In this case, the numbers of the CCEs 404 can be allocated according to a logical mapping method.

[0151] Figure 4The basic unit of the PDCCH shown, i.e., the REG 403, can include REs to which DCI is mapped and a region to which a DMRS 405 is mapped, the DMRS 405 being a reference signal for decoding the DCI. As shown, three DMRSs 405 can be transmitted within 1 REG 403. The number of CCEs required to transmit a PDCCH can be 1, 2, 4, 8, or 16 according to an aggregation level (AL). Different numbers of CCEs can be used to implement link adaptation of the PDCCH. For example, when AL=L, one PDCCH can be transmitted through L CCEs. Figure 4

[0152] In a state in which the terminal does not know information about the PDCCH, the terminal needs to detect a signal. A search space indicating a set of CCEs can be defined for blind decoding. The search space is a set of candidate PDCCHs consisting of CCEs that the terminal must attempt to decode in a given aggregation level. Since there are several aggregation levels consisting of a bundle of 1, 2, 4, 8, or 16 CCEs, the terminal can have multiple search spaces. A search space set can be defined as a set of search spaces in all configured aggregation levels.

[0153] The search space can be classified into a common search space and a UE-specific search space. According to an embodiment of the disclosure, a given terminal group or all terminals can check the common search space of the PDCCH to receive dynamic scheduling of system information or cell common control information such as a paging message.

[0154] For example, the terminal can search for PDSCH scheduling allocation information for transmitting an SIB, in which information of a cell service provider or the like is included, in the common search space of the PDCCH, and can receive the PDSCH scheduling allocation information. In the case of the common search space, a given terminal group or all terminals must receive the PDCCH. Accordingly, the common search space can be defined as a previously agreed set of CCEs. Meanwhile, the terminal can search for scheduling allocation information for a UE-specific PDSCH or PUSCH in the UE-specific search space of the PDCCH, and can receive the scheduling allocation information. The UE-specific search space can be defined as a function of a terminal identity and various system parameters in a UE-specific manner.

[0155] ​In 5G, parameters in a search space for a PDCCH can be configured by a base station to a terminal using higher layer signaling (e.g., SIB, MIB, or RRC signaling). For example, the base station can configure the number of candidate PDCCHs in each aggregation level L, a monitoring period for a search space, a monitoring occasion in a slot for a search space in units of symbols, a search space type (common search space or UE-specific search space), a DCI format to be monitored in a corresponding search space, a combination of RNTIs, a CORESET index to monitor a search space, and the like for the terminal. For example, the foregoing configuration can include information such as the following [Table 10].

[0156] [Table 10]

[0157]

[0158]

[0159]

[0160] The base station can configure one or more search space sets for the terminal based on the configuration information. According to an embodiment of the disclosure, the base station can configure the terminal with search space set 1 and search space set 2, can configure the terminal so that the terminal monitors a DCI format A scrambled by an X-RNTI in the search space set 1 in a common search space, and can configure the terminal so that the terminal monitors a DCI format B scrambled by a Y-RNTI in the search space set 2 in a UE-specific search space.

[0161] According to the configuration information, the common search space or the UE-specific search space can include one or more search space sets. For example, search space set #1 and search space set #2 can be configured as a common search space, and search space set #3 and search space set #4 can be configured as a UE-specific search space.

[0162] The common search space can be classified into a specific type of search space set according to its purpose. For each determined search space set type, the RNTI to be monitored can be different from each other. For example, the common search space type, purpose, and RNTI to be monitored can be classified as follows in Table 10a.

[0163] [Table 10a]

[0164]

[0165]

[0166] Meanwhile, in the common search space, the following combinations of DCI formats and RNTIs can be monitored. The disclosure is not limited to the following examples.

[0167] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0168] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0169] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0170] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0171] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0172] In the UE-specific search space, the following combinations of DCI formats and RNTIs can be monitored. The present disclosure is not limited to the following examples.

[0173] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0174] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0175] A specific RNTI can follow the definitions and usage as follows.

[0176] C-RNTI (Cell RNTI): for UE-specific PDSCH scheduling

[0177] TC-RNTI (Temporary Cell RNTI): for UE-specific PDSCH scheduling

[0178] CS-RNTI (Configured Scheduling RNTI): for semi-statically configured UE-specific PDSCH scheduling

[0179] RA-RNTI (Random Access RNTI): for PDSCH scheduling in random access procedure

[0180] P-RNTI (Paging RNTI): for scheduling PDSCH transmitting paging

[0181] SI-RNTI (System Information RNTI): for scheduling PDSCH transmitting system information

[0182] INT-RNTI (Interruption RNTI): for providing notification of whether to puncture PDSCH

[0183] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): used for indicating power adjustment command for PUSCH

[0184] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): used for indicating power adjustment command for PUCCH

[0185] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): used for indicating power adjustment command for SRS

[0186] In an embodiment, the aforementioned DCI formats can be defined as below [Table 11].

[0187] [Table 11]

[0188]

[0189] In 5G, the search space in a control resource set p and a search space set s at an aggregation level L can be expressed as the following equation.

[0190] [Equation 2]

[0191]

[0192] -L: aggregation level

[0193] -n CI : carrier index

[0194] -N CCE,p : total number of CCEs existing within the control resource set p

[0195] -n μ s,f : slot index

[0196] -M (L) p,s,max : number of candidate PDCCHs at the aggregation level L

[0197] -m snCI = 0, …, M (L) p,s,max -1: candidate PDCCH index at the aggregation level L

[0198] -i = 0, …, L - 1

[0199]

[0200] A1 = 39829, A2 = 39839, D = 65537

[0201] -n RNTI : UE identity

[0202] In the case of the common search space, Y_(p,n μ s,f ) values can correspond to 0.

[0203] In the case of the UE-specific search space, Y_(p,n μ s,f ) values can correspond to values that vary according to an identity of the UE (C-RNTI or ID configured for the UE by the base station) and a time index.

[0204] According to embodiments of the disclosure, in 5G, a plurality of search space sets can be configured as different parameters (e.g., parameters in [Table 10]). Thus, a set of search space sets monitored by a terminal at each timing can be different. For example, if search space set #1 is configured in an X-slot period and search space set #2 is configured in a Y-slot period, the terminal can monitor both search space set #1 and search space set #2 in a certain slot when X and Y are different, and can monitor one of search space set #1 and search space set #2 in a certain slot.

[0205] Meanwhile, the NR system employs an asynchronous HARQ method in which data retransmission timing is not fixed with respect to uplink / downlink HARQ. Described is the downlink as an example, when the base station receives HARQ negative feedback from the terminal regarding initial transmission data transmitted by the base station, the base station freely determines transmission timing of retransmission data through a scheduling operation. The terminal can buffer data determined as an error as a result of decoding received data as a HARQ operation, and can combine data retransmitted by the base station. HARQ ACK / NACK information for PDSCH transmitted in subframe n-k can be transmitted from the terminal to the base station through PUCCH or PUSCH in subframe n. In the case of a 5G communication system such as NR, a k value is transmitted through DCI included in DCI indicating or scheduling PDSCH reception transmitted in subframe n-k, or the k value can be configured to the terminal through a higher layer signal. In this case, the base station can configure one or more k values through a higher layer signal, and can indicate a specific k value through DCI. In this case, k can be determined based on HARQ-ACK processing capability of the terminal, in other words, a minimum time required for the terminal to receive PDSCH and generate and report HARQ-ACK for the PDSCH. Further, the terminal can use a predetermined value or a default value until a k value is configured for the terminal.

[0206] Next, a resource region in which a data channel is transmitted in a 5G communication system is described.

[0207] Figure 5 is a diagram illustrating a resource region in which a data channel is transmitted in a 5G communication system.

[0208] The terminal monitors to search for a PDCCH 510 in a downlink control channel (hereinafter, referred to as a PDCCH) region (hereinafter, referred to as a control resource set (CORESET) to a search space (SS)) configured through a higher layer signal from the base station. In this case, the CORESET is constituted of time domain (514) and frequency domain (512) information. The time domain (514) information can be configured in units of symbols, and the frequency domain (512) information can be configured in units of RBs or RB groups. If the terminal detects the PDCCH 510 in the slot i 500, the terminal obtains downlink control information (DCI) transmitted through the detected PDCCH 510. The terminal can obtain scheduling information for a downlink data channel or an uplink shared channel through the received DCI. In other words, the DCI can include information of a resource region (or a PDSCH transmission region) in which the terminal must receive at least a physical downlink shared channel (hereinafter, referred to as a PDSCH) from the base station, or information of a resource region allocated to the terminal by the base station for PUSCH transmission. The following will be described taking a case in which the terminal is scheduled for PUSCH transmission as an example. The terminal that has received the DCI can obtain a slot index or offset information K based on which the terminal must receive the PUSCH through the DCI, and can determine a PUSCH transmission slot index. For example, the terminal can determine that it has been scheduled to transmit the PUSCH in the slot i+K 505 through the received offset information K based on the slot index i 500 in which the PDCCH 510 has been received. In this case, the terminal can also determine a PUSCH start symbol or time in the slot i+K 505 or the slot i+K through the received offset information K based on the CORESET in which the PDCCH 510 has been received. Further, the terminal can obtain information on a PUSCH transmission time-frequency resource region 540 in the PUSCH transmission slot 505 from the DCI. In this case, the PUSCH transmission frequency resource region information 530 can be PRB to PRB group unit information. Meanwhile, the PUSCH transmission frequency resource region information 530 is a region included in an initial uplink bandwidth (BW) 535 or an initial uplink BWP 535 that has been determined by the terminal or configured for the terminal through an initial access procedure. If the terminal is configured with an uplink BW or an uplink BWP through a higher layer signal, the PUSCH transmission frequency resource region information 530 is a region included in the uplink BW or the uplink BWP configured for the terminal through a higher layer signal.

[0209] The PUSCH transmission time resource field information 525 can be group unit information of symbols to symbols, or information indicating absolute time information. In this case, the PUSCH transmission time resource field information 525 can be expressed as a combination of a PUSCH transmission start time or symbol length and a PUSCH or PUSCH end time or symbol, and can be included in the DCI as one field value. In this case, the PUSCH transmission time resource field information 525 can be included in the DCI as one field value, indicating the PUSCH transmission start time or symbol length and each of the PUSCH or PUSCH end time or symbol. The terminal can transmit the PUSCH in the PUSCH transmission resource field 540 determined through the DCI.

[0210] Hereinafter, a method of allocating a frequency domain resource for a data channel in a 5G communication system is described.

[0211] As a method of indicating the frequency domain resource allocation information of the PDSCH and the PUSCH, 5G supports three types: resource allocation type 0, resource allocation type 1, and resource allocation type 2.

[0212] Resource allocation type 0

[0213] The base station can notify the terminal of the RB allocation information in the form of a resource block group (RBG) bitmap. In this case, the RBG can be composed of a group of consecutive virtual RBs (VRBs). The size P of the RBG can be determined based on a value (rbg-Size) configured as a higher layer parameter and a value of the BWP size defined in the following table.

[0214] [Table 12]

[0215] Bandwidth part size Configuration 1 Configuration 2 1-36 2 4 37-72 4 8 73-144 8 16 145-275 16 16

[0216] The total number (N RBG ) of RBGs in the BWP i of size may be defined as follows.

[0217] where

[0218] The size of the first RBG is

[0219] If , the size of the last RBG is otherwise P,

[0220] The size of all other RBGs is P.

[0221] The bit size is N RBG ​Each bit in the bitmap can correspond to each RBG. The index of the RBG can be allocated in the order of increasing frequency from the lowest frequency position of the BWP. RBG #0 to RBG # (N RBG -1) can be mapped to N RBG RBGs from the MSB to the LSB in the RBG bitmap within the BWP. When a particular bit value in the bitmap is 1, the terminal can determine that the RBG corresponding to the particular bit value has been allocated; and when a particular bit value in the bitmap is 0, the terminal can determine that the RBG corresponding to the particular bit value has not been allocated.

[0222] Resource allocation type 1

[0223] - The base station can inform the terminal of RB allocation information as information on the start position and length of the continuously allocated VRB. In this case, interleaving or non-interleaving can also be applied to the continuously allocated VRB. The resource allocation field of the resource allocation type 1 can be composed of a resource indication value (RIV). The RIV can be composed of the start point (RB start ) of the VRB and the length (L RBs ) of the continuously allocated RB. More specifically, the RIV within the BWP of size may be defined as follows.

[0224] ■If then

[0225] ◆

[0226] ■Else

[0227] ◆

[0228] ■where L RBs -1 should not exceed

[0229] Resource allocation type 2

[0230] - The base station can inform the terminal of RB allocation information as a set of M interleaving indices.

[0231] - The interleaving index m ∈ {0, 1,..., M-1} can be composed of the common RB {m, M+m, 2M+m, 3M = m,...}, and M can be defined as in Table 8.

[0232] [Table 13]

[0233] μ M 0 10 1 5

[0234] The relationship between the interleaving m in the BWP i and the common may be defined as follows.

[0235]

[0236] ■wherein, is a common resource block where the BWP starts with respect to the common resource block 0. u is a subcarrier spacing index

[0237] - When the subcarrier spacing is 15 kHz (u = 0), the base station can inform the terminal of RB allocation information for the interleaving set as m0+1 indexes. In addition, the resource allocation field can be composed of a resource indication value (RIV). When the RIV is 0≤RIV

[0238] If then

[0239] RIV = M(L-1) + m0

[0240] Otherwise

[0241] RIV = M(M-L+1) + (M-1-m0)

[0242] When the RIV is RIV≥M(M+1) / 2, the RIV is composed of a starting interleaving index m0and an l value, and can be composed as Table 14.

[0243] [Table 14]

[0244] RIV - M(M+1) / 2 m0 l 0 0 {0，5} 1 0 {0，1，5，6} 2 1 {0，5} 3 1 {0，1，2，3，5，6，7，8} 4 2 {0，5} 5 2 {0，1，2，5，6，7} 6 3 {0，5} 7 4 {0，5}

[0245] - When the subcarrier spacing is 30 kHz (u = 1), the base station can inform the terminal of RB allocation information in the form of a bitmap indicating interleaving allocated to the terminal. The size of the bitmap is M, and one bit in the bitmap corresponds to each interleaving. In the order of the interleaving bitmap, interleaving indexes 0 to M-1 can be mapped to MSB to LSB in the interleaving bitmap.

[0246] Next, a method of configuring a beam for a terminal by a base station to transmit control information and data is described. In the present disclosure, for convenience of description, a process of transmitting control information through a PDCCH can be expressed as transmitting a PDCCH, and a process of transmitting data through a PDSCH can be expressed as transmitting a PDSCH.

[0247] First, a configuration method of a beam for a PDCCH is processed in detail.

[0248] Figure 6 ​The procedure of configuring and activating PDCCH beams is shown. First, the list of TCI states can be indicated by a higher layer list such as RRC (6-00) per CORESET. The list of TCI states can be indicated as tci-statesPDCCH-ToAddList and / or tci-statesPDCCH-ToReleaseList in Table 8. Next, one of the list of TCI states configured per CORESET can be activated by a MAC-CE (6-20). 6-50 shows an example of the MAC-CE structure for TCI state activation for PDCCH. The meaning of each field within the MAC CE and the values that can be configured in each field are as follows.

[0249]

[0250] Next, the beam configuration method for PDSCH is described.

[0251] Figure 7 The procedure of configuring and activating PDSCH beams is shown. The list of TCI states for PDSCH can be indicated by a higher layer list such as RRC (7-00). For example, the list of TCI states can be indicated as tci-StatesToAddModList and / or tci-StatesToReleaseList within the PDSCH-Config IE per BWP. Next, some of the list of TCI states can be activated by a MAC-CE (7-20). The maximum number of activated TCI states can be determined according to the capability reported by the terminal. (7-50) shows an example of the MAC-CE structure for TCI state activation / deactivation for PDSCH based on Rel-15.

[0252] The meaning of each field within the MAC CE and the values that can be configured in each field are as follows.

[0253]

[0254]

[0255] When receiving the DCI format 1_1 or the DCI format 1_2, the terminal can receive the PDSCH through one beam among the TCI activated by the MAC-CE based on the information of the transmission configuration indication (TCI) field within the DCI (7-40). Whether the TCI field is present is determined by the value of tci-PresentinDCI, i.e., a higher layer parameter within the CORESET configured for receiving the DCI. If tci-PresentinDCI in the higher layer is configured as "enable", the terminal can determine the TCI state activated in the DL_BWP or the scheduled component carrier and the beam direction associated with the DL_RS by recognizing the 3-bit TCI field information.

[0256] In LTE and NR, the terminal has a procedure of reporting the capability supported by the terminal in a state in which the terminal has connected to a serving base station to the corresponding base station. This is expressed as UE capability (reporting) in the following description. The base station can transmit a UE capability inquiry message requesting a capability report to the terminal in a connected state. The message can include the UE capability request of the base station per RAT type. The request per RAT type can include requested band information. In addition, the UE capability inquiry message can request multiple RAT types in one RRC message container, or the UE capability inquiry message including the request per RAT type can be included and transmitted to the terminal multiple times. That is, the UE capability inquiry can be repeated multiple times, and the terminal can constitute a UE capability information message corresponding to the UE capability inquiry and report the UE capability information message multiple times. In the next-generation mobile communication system, the UE capability request can be made for MR-DC in addition to NR, LTE, and EN-DC. For reference, the UE capability inquiry message is generally transmitted initially after the terminal is connected, but can be requested even when the base station needs the UE capability inquiry message.

[0257] In this step, the terminal receiving the UE capability report request from the base station constitutes the UE capability based on the RAT type and the band information requested by the base station. The method of constituting the UE capability by the terminal in the NR system is given below.

[0258] 1. If the LTE and / or NR band list is provided to the terminal as the UE capability request from the base station, the terminal constitutes the band combination (BC) for EN-DC and NR alone (SA). That is, the terminal constitutes the BC candidate list for EN-DC and NR-SA based on the band requested by the base station as FreqBandList. In addition, the bands have priority arranged in the order written in FreqBandList.

[0259] 2. If the base station sets the flag "eutra-nr-only" or the flag "eutra" and requests the UE capability report, the terminal completely removes the BC of the NR SA from the composed BC candidate list. Such an operation occurs only when the LTE base station (eNB) requests the "eutra" capability.

[0260] 3. Thereafter, the terminal removes the fallback BC from the BC candidate list composed in the above-described step. In this case, the fallback BC corresponds to a case where the frequency band corresponding to at least one SCell has been removed from the superset BC, and since the superset BC can have covered the fallback BC, this step can be omitted. This step is also applicable to the MR-DC. That is, this step is also applicable to the LTE band. The BC remaining after this step is the final "candidate BC list".

[0261] 4. The terminal selects the BC suitable for the requested RAT type from the final "candidate BC list" and selects the BC to be reported. In this step, the terminal composes the supportedBandCombinationList in the determined order. That is, the terminal composes the BC to be reported and the UE capability based on the order of the previously configured RAT type (nr -> eutra-nr -> eutra). In addition, the terminal composes the featureSetCombination with respect to the composed supportedBandCombinationList, and composes the "candidate feature set combination" list in the candidate BC list, where the list of the fallback BC (including the capability having the same or less steps) has been deleted. The "candidate feature set combination" includes all feature set combinations of the BC in the NR and the EUTRA-NR, and can be obtained from the feature set combinations of the UE-NR-Capabilities and the UE-MRDC-Capabilities containers.

[0262] 5. In addition, if the requested RAT type is eutra-NR and has the impact, the featureSetCombinations are completely included in both the UE-NR-Capabilities and the UE-MRDC-Capabilities containers. However, the feature set of the NW includes only the UE-NR-Capabilities.

[0263] After composing the UE capability, the terminal transmits the UE capability information message including the UE capability to the base station. The base station subsequently performs scheduling, transmission, and reception management suitable for the terminal based on the UE capability received from the terminal.

[0264] Meanwhile, if the interval between the symbol in which the PDCCH transmission ends and the starting symbol of the PDSCH scheduled by the PDCCH is less than a certain threshold, the terminal can not complete the decoding of the PDCCH at the timing of receiving the PDSCH. This means that the beam information indicated in the DCI in the PDCCH is not received for the PDSCH reception. In this case, the base station and the terminal can designate a basic beam for the PDSCH reception. That is, in this case, the base station transmits the PDSCH through the designated basic beam, and the terminal performs buffering through the designated basic beam. If the terminal has determined that there is a scheduled PDSCH at the timing before the PDCCH decoding after the PDCCH decoding, the terminal can perform PDSCH decoding from the buffered signal based on the basic beam. In this case, the aforementioned threshold can be a value timeDurationForQCL reported as a UE capability. Meanwhile, the basic beam operation can be limited to the case where one or more TCI states in the TCI state list 7-00 configured for the PDSCH include QCL-TypeD, i.e., the case where the reception beam of the terminal is accompanied. In this case, the basic beam can be the beam that has been configured in the CORESET (e.g., CORESET#0) corresponding to the lowest ID among the CORESETs corresponding to the search space monitored in the latest slot at the time of the PDSCH reception.

[0265] The basic beam operation for the PDSCH reception can be limited to the case where the cross-carrier configuration for the PDSCH has not been performed.

[0266] Figure 8 An example of the PDSCH basic beam operation is shown. When the TCI field for receiving the PDSCH within the DCI 8-00 transmitted through the PDCCH indicates the TCI state #n 8-10, if the interval between the symbol in which the PDCCH transmission ends and the starting symbol of the PDSCH 8-40 scheduled by the PDCCH is less than timeDurationForQCL 8-20, and one or more TCI states in the TCI state list for the PDSCH configured through RRC include QCL-TypeD, the basic beam 8-60 is applied to the PDSCH.

[0267] Meanwhile, if a parameter tci-PresentinDCI is not configured within the CORESET or if the PDSCH is scheduled in DCI format 1_0, the terminal does not receive a beam indication for PDSCH reception since there is no TCI field within the DCI. In this case, if the interval between the symbol in which the PDCCH transmission ends and the starting symbol of the PDSCH scheduled by the PDCCH is greater than or equal to a value timeDurationForQCL, the terminal can assume that the beam for receiving the PDSCH is the same as the beam configured / activated in the PDCCH transmission CORESET. The base station can configure the PDSCH transmission beam based on the assumption of the terminal. If cross-carrier configuration for the PDSCH is not performed, the basic beam operation for PDSCH reception can be limited.

[0268] In NR, if the base station schedules the PDSCH for the terminal by using DCI format 1_0 or DCI format 1_1, the terminal can transmit HARQ-ACK feedback information for the PDSCH to the base station through the PUCCH. The base station indicates, to the terminal, a slot to which the PUCCH for transmitting the HARQ-ACK feedback information is mapped and a type of PUCCH resource through the DCI scheduling the PDSCH. Specifically, the base station can indicate a time slot offset between the PDSCH and the PUCCH for transmitting the HARQ-ACK feedback information through the PDSCH-to-HARQ_feedback timing indicator field in the DCI scheduling the PDSCH. In addition, the base station can indicate a type of PUCCH resource for transmitting the HARQ-ACK feedback information through the PUCCH resource indicator in the DCI scheduling the PDSCH.

[0269] When the PDSCH is scheduled based on the DCI information in the PDCCH, information of a slot to which the PUCCH is mapped, and information of symbol mapping within the PUCCH slot including the HARQ-ACK feedback are transmitted, in which the PDSCH is transmitted and includes the HARQ-ACK feedback corresponding to the PDSCH. Specifically, the slot interval K2 between the PDSCH and the HARQ-ACK feedback corresponding to the PDSCH is indicated by the PDSCH-to-HARQ_feedback timing indicator. One of eight feedback timing offsets configured by higher layer signaling or previously determined from 1 to 8 is indicated as a candidate value of the slot interval. In addition, in order to transmit the PUCCH format to which the HARQ-ACK feedback information is mapped, the position of the starting symbol, or the PUCCH resource including the number of mapping symbols, one of eight resources configured by the higher layer is indicated by the PUCCH resource indicator. The terminal determines the time domain mapping position of the PUCCH including the HARQ-ACK feedback, with reference to the slot interval between the PDSCH and the HARQ-ACK feedback corresponding to the PDSCH, and the starting symbol position and the number of mapping symbols configured in the PUCCH resource. In addition, the terminal maps the HARQ-ACK feedback information based on the PUCCH format configured in the PUCCH resource.

[0270] The spatial domain transmission filter of the terminal transmitting the PUCCH complies with the spatial relation information of the PUCCH, which is activated by higher layer signaling including the MAC CE in the PUCCH resource of the terminal. If the activated spatial relation information in the PUCCH resource refers to the index of the CSI reference signal (RS) resource or the synchronization / broadcast channel block (SS / PBCH block, SSB), the terminal can transmit the PUCCH by using the spatial domain transmission filter, such as the spatial domain reception filter used for receiving the reference CSI-RS resource or the SSB. Alternatively, if the activated spatial relation information in the PUCCH resource refers to the sounding reference signal (SRS) resource index, the terminal can transmit the PUCCH by using the spatial domain transmission filter that has been used to transmit the reference SRS resource. The foregoing configuration can include information such as [Table 15].

[0271] [Table 15]

[0272]

[0273] Next, a method of estimating an uplink channel by a terminal using sounding reference signal (SRS) transmission is described. A base station can configure at least one SRS configuration for each uplink BWP to transmit configuration information for SRS transmission to a terminal, and can configure at least one SRS resource set for each SRS configuration. For example, the base station and the terminal can exchange the following signaling information to transmit information about the SRS resource set.

[0274] - srs-ResourceSetId: index of the SRS resource set

[0275] - srs-ResourceIdList: set of SRS resource indices referred to in the SRS resource set

[0276] - resourceType: this is a time domain transmission configuration of the SRS resource referred to in the SRS resource set, and can have one of "periodic", "semi-persistent", or "aperiodic". If the resourceType is configured as "periodic" or "semi-persistent", relevant CSI-RS information can be provided according to the usage of the SRS resource set. If the resourceType is configured as "aperiodic", an aperiodic SRS resource trigger list and slot offset information can be provided. According to the usage of the SRS resource set, relevant CSI-RS information can be provided.

[0277] - Usage: this is a usage configuration of the SRS resource referred to in the SRS resource set, and can have one of "beamManagement", "(codebook) codebook", "nonCodebook", or "antennaSwitching".

[0278] - alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: this provides a parameter configuration for adjusting the transmission power of the SRS resource referred to in the SRS resource set.

[0279] The terminal can understand that the SRS resource included in the SRS resource index referred to in the SRS resource set complies with the information configured in the SRS resource set.

[0280] Further, the base station and the terminal can exchange higher layer signaling information to transmit various configuration information for the SRS resource. For example, the various configuration information for the SRS resource can include time-frequency domain mapping information within the SRS resource slot. The time-frequency domain mapping information can include information on frequency hopping within or across the SRS resource slot. Further, for example, the various configuration information for the SRS resource can include time domain transmission configuration of the SRS resource, and can have one of "periodic", "semi-persistent", or "aperiodic". This can be limited to have the time domain transmission configuration, such as a SRS resource set included in the SRS resource. If the time domain transmission configuration of the SRS resource is configured as "periodic" or "semi-persistent", the time domain transmission configuration can further include transmission periodicity and slot offset (e.g., periodicityAndOffset) of the SRS resource. The base station can activate, disable, or trigger the SRS transmission of the terminal through higher layer signaling including RRC signaling or MAC CE signaling or L1 signaling (e.g., DCI).

[0281] For example, the base station can activate or disable the periodic SRS transmission of the terminal through higher layer signaling. The base station can indicate to activate the SRS resource set for which resourceType has been configured periodically through higher layer signaling. The terminal can transmit the SRS resource with reference to the activated SRS resource set. The time-frequency domain resource mapping within the slot in which the SRS resource is transmitted complies with the resource mapping information configured in the SRS resource. The slot mapping including the transmission periodicity and the slot offset complies with the periodicityAndOffset configured in the SRS resource. Further, the spatial domain transmission filter applied to transmit the SRS resource can refer to the spatial relation information configured in the SRS resource, or can refer to the associated CSI-RS information configured in the SRS resource set including the SRS resource. For the periodic SRS resource activated through the higher layer signaling, the terminal can transmit the SRS resource within the activated uplink BWP.

[0282] For example, the base station can activate or deactivate the terminal's semi-persistent SRS transmission through higher layer signaling. The base station can indicate to activate the SRS resource set through MAC CE signaling. The terminal can transmit the SRS resource representing the activated SRS resource set. The SRS resource set activated through the MAC CE signaling can be limited to the SRS resource set whose resourceType has been configured as semi-persistent. The time-frequency domain resource mapping within the slot in which the SRS resource is transmitted complies with the resource mapping information configured in the SRS resource. The slot mapping including the transmission period and the slot offset complies with the periodicityAndOffset configured in the SRS resource. In addition, the spatial domain transmission filter applied to the SRS resource transmitted can refer to the spatial relation information configured in the SRS resource or can refer to the associated CSI-RS information configured in the SRS resource set including the SRS resource. If the spatial relation information has been configured in the SRS resource, the spatial domain transmission filter can be determined with reference to the configuration information for the spatial relation information transmitted through the MAC CE signaling that activates the semi-persistent SRS transmission, without complying with the spatial relation information. The terminal can transmit the SRS resource within the activated uplink BWP with respect to the semi-persistent SRS resource activated through the higher layer signaling.

[0283] For example, the base station can trigger the terminal's aperiodic SRS transmission through DCI. The base station can indicate one of the aperiodic SRS resource triggers through the SRS request field of the DCI. The terminal can understand that, in the configuration information of the SRS resource set, the SRS resource set including the aperiodic SRS resource trigger indicated through the DCI within the list of aperiodic SRS resource triggers has been triggered. The terminal can transmit the SRS resource referred to in the triggered SRS resource set. The time-frequency domain resource mapping within the slot in which the SRS resource is transmitted complies with the resource mapping information configured in the SRS resource. In addition, the slot mapping in which the SRS resource is transmitted can be determined through the slot offset between the PDCCH including the DCI and the SRS resource. This can refer to the value included in the set of slot offsets configured in the SRS resource set. Specifically, the slot offset between the PDCCH including the DCI and the SRS resource can apply the value indicated in the time domain resource allocation field of the DCI among the offset values included in the set of slot offsets configured in the SRS resource set. In addition, the spatial domain transmission filter applied to the SRS resource transmitted can refer to the spatial relation information configured in the SRS resource or can refer to the associated CSI-RS information configured in the SRS resource set including the SRS resource. The terminal can transmit the SRS resource within the activated uplink BWP with respect to the aperiodic SRS resource triggered through the DCI.

[0284] If the base station triggers the terminal's aperiodic SRS transmission through the DCI, in order to transmit the SRS by applying the configuration information of the SRS resource, the terminal can need a minimum time interval between the PDCCH including the DCI that triggered the aperiodic SRS transmission and the SRS transmission. The time interval for the terminal's SRS transmission can be defined as the number of symbols between the last symbol in the PDCCH including the DCI that triggered the aperiodic SRS transmission and the first symbol to which the first transmitted SRS resource among the SRS resources is mapped. The minimum time interval can be determined with reference to the time of the PUSCH preparation procedure required for the terminal to prepare for the PUSCH transmission. In addition, the minimum time interval can have different values according to the usage of the SRS resource set including the SRS resource for transmission. For example, the minimum time interval can be determined as N2 symbols defined by considering the terminal processing capability according to the UE capability and with reference to the PUSCH preparation procedure time of the terminal. In addition, if the usage of the SRS resource set is configured as "codebook" or "antennaSwitching" in consideration of the usage of the SRS resource set including the SRS resource for transmission, the minimum time interval can be defined as N2 symbols. If the usage of the SRS resource set is configured as "nonCodebook" or "beamManagement", the minimum time interval can be determined as N2+14 symbols. When the time interval for the aperiodic SRS transmission is greater than or equal to the minimum time interval, the terminal can transmit the aperiodic SRS; and when the time interval for the aperiodic SRS transmission is less than the minimum time interval, the terminal can ignore the DCI that triggers the aperiodic SRS.

[0285] [table 16]

[0286]

[0287] By using the beam information for one reference signal of the corresponding reference signal, the spatialRelationInfo configuration information in [table 16] can be applied to the beam used in the corresponding SRS transmission. For example, the configuration of the spatialRelationInfo can include information such as the following [table 17].

[0288] [table 17]

[0289]

[0290] Referring to the spatialRelationInfo configuration, in order to use the beam information of a specific reference signal, a reference signal index, i.e., an SS / PBCH block index, a CSI-RS index, or an SRS index, to be referred to can be configured. The higher layer signaling reference signal is configuration information indicating which beam information of a reference signal will be referred to for a corresponding SRS transmission. The ssb-Index refers to an index of an SS / PBCH block, the csi-RS-Index refers to an index of a CSI-RS, and the srs refers to an index of an SRS. If the value of the higher layer signaling reference signal is configured as "ssb_Index", the terminal can apply a reception beam that has been used when an SS / PBCH block corresponding to the ssb_Index is received as a transmission beam for a corresponding SRS transmission. If the value of the higher layer signaling reference signal is configured as "csi-RS-Index", the terminal can apply a reception beam that has been used when a CSI-RS corresponding to the csi-RS-Index is received as a transmission beam for a corresponding SRS transmission. If the value of the higher layer signaling reference signal is configured as "srs", the terminal can apply a transmission beam that has been used when an SRS corresponding to the srs is transmitted as a transmission beam for a corresponding SRS transmission.

[0291] The NR communication system can transmit an uplink signal (configured grant PUSCH or CG-PUSCH) without uplink scheduling information to provide various services and support a high data transmission rate. More specifically, if an uplink signal is to be transmitted without uplink scheduling information, resource allocation information for uplink transmission, MCS, etc. can be configured through RRC signaling or DCI in a PDCCH. According to a method of receiving an uplink transmission configuration, the uplink transmission that can be performed can be described by dividing the uplink transmission into at least the following types.

[0292] Type 1: uplink transmission configuration using RRC signaling

[0293] Type 2: uplink transmission configuration using PDCCH of a physical layer

[0294] In Type 1, the base station can configure a terminal with a specific time / frequency resource that authorizes non-licensed based PUSCH transmission through higher layer signaling (e.g., RRC signaling). In addition, the base station can configure the terminal with various parameters (e.g., frequency hopping, DMRS configuration, MCS table, MCS, RBG size, number of retransmissions, or RV) for PUSCH transmission through higher layer signaling. When receiving the configuration information for Type 1 PUSCH transmission from the base station, the terminal can transmit the PUSCH through the periodically configured resource without the permission of the base station. All various parameters (e.g., frequency hopping, DMRS configuration, MCS, RBG size, number of retransmissions, RV, number of precoding layers, antenna port, and frequency hopping offset) required to transmit the PUSCH can comply with the configured values informed by the base station.

[0295] In Type 2, the base station can configure a terminal with some information (e.g., periodicity information) for a specific time / frequency resource that authorizes non-licensed based PUSCH transmission through higher layer signaling (e.g., RRC signaling). In addition, the base station can configure the terminal with various parameters (e.g., frequency hopping, DMRS configuration, MCS table, RBG resource block group (RBG) size, number of retransmissions, and redundancy version (RV)) for PUSCH transmission through higher layer signaling. The base station can transmit DCI (validation DCI) consisting of a specific DCI field that schedules activation of Type 2 CG-PUSCH or scheduling release of Type 2 CG-PUSCH to the terminal. More specifically, the base station can configure the terminal with a CS-RNTI. The terminal can monitor the DCI format with CRC scrambled by the CS-RNTI. If the CRC of the DCI format received by the terminal has been scrambled by the CS-RNTI and the new data indicator value included in the corresponding DCI is 0, the terminal can determine that the corresponding DCI is for validating the DCI that schedules activation of Type 2 CG-PUSCH or scheduling release of Type 2 CG-PUSCH (validation DCI). When the validation of Type 2 CG-PUSCH transmission is completed, the terminal can determine whether Type 2 CG-PUSCH transmission is activated or released based on the specific field value of the corresponding DCI. For example, if the specific field value has a value such as Table 10 according to the DCI format, the terminal can determine that Type 2 CG-PUSCH is activated. In addition, for example, if the specific field value has a value such as Table 19 according to the DCI format, the terminal can determine that Type 2 CG-PUSCH has been released.

[0296] [Table 18]

[0297]

[0298] [Table 19]

[0299]

[0300] Figure 9 is a diagram illustrating transmission of an uplink signal in an unlicensed band without uplink scheduling information.

[0301] In the unlicensed band, a channel access procedure is performed to transmit an uplink signal without uplink scheduling information. In this case, if the terminal accesses the unlicensed band by performing a channel access procedure at a variable time, the terminal can schedule a downlink transmission 909 in the last slot 904 or the last subframe 904 within the maximum channel occupancy time 912 through the channel occupancy time sharing indicator of the uplink control information 905. In this case, the base station can determine channel access by performing a channel access procedure at a fixed time. The terminal can configure the last symbol in the slot 903 or the subframe 903 for uplink transmission as a gap interval that is emptied for the channel access procedure of the base station. When transmitting a CG-PUSCH in the unlicensed band, the terminal can transmit the CG-PUSCH by including CG-UCI of the CG-PUSCH in the CG-PUSCH, the CG-UCI including a HARQ ID, an RV, CG-PUSCH scheduling information, etc. of the CG-PUSCH. In this case, all CG-PUSCHs can include at least one CG-UCI.

[0302] In the case where the system performs communication in the unlicensed band, a transmission device (base station or terminal) that attempts to transmit a signal through the unlicensed band can perform a channel access procedure (or listen before talk (LBT)) on the unlicensed band where communication is performed before transmitting the signal, and can perform signal transmission by accessing the unlicensed band when it is determined that the unlicensed band is in an idle state according to the channel access procedure. If it is determined that the unlicensed band is not in the idle state according to the performed channel access procedure, the transmission device does not perform signal transmission.

[0303] Generally, in the channel access procedure in the unlicensed band, the idle state of the unlicensed band can be determined by measuring the strength of a signal received through the unlicensed band at a fixed time or a time calculated according to a predetermined rule (for example, a time calculated by at least one random value selected by the base station or the terminal), and comparing the measured strength with a threshold value defined in advance or calculated by a function for determining the size of the received signal strength, the function being composed of at least one variable among a channel bandwidth, a signal bandwidth of a signal to be transmitted, and the strength of a transmission power.

[0304] For example, the transmitting apparatus can measure the signal strength for X μs (e.g., 25 μs) just before the transmitting apparatus attempts to transmit a signal, can determine that the unlicensed band is in an idle state and can transmit a configured signal when the measured signal strength is less than a previously defined or calculated threshold T (e.g., -72 dBm). In this case, the maximum time during which a signal can be continuously transmitted after a channel access procedure can be limited based on the maximum channel occupancy time defined for each country, region, or band according to each unlicensed band, and can be limited according to the type of the transmitting apparatus (e.g., a base station or terminal, or a master apparatus or slave apparatus). For example, in the case of Japan, in an unlicensed band of 5 GHz, a base station or terminal can perform a channel access procedure and then can transmit a signal by occupying a channel on an unlicensed band determined to be in an idle state for up to 4 ms without performing an additional channel access procedure.

[0305] More specifically, when a base station or terminal attempts to transmit a downlink or uplink signal in an unlicensed band, the channel access procedure that can be performed by the base station or terminal can be described by dividing the channel access procedure into at least the following types.

[0306] Type 1: Transmission of an uplink / downlink signal after a channel access procedure for a variable time

[0307] Type 2: Transmission of an uplink / downlink signal after a channel access procedure for a fixed time

[0308] Type 3: Transmission of a downlink or uplink signal without performing a channel access procedure

[0309] Hereinafter, in the present disclosure, a case in which a base station transmits a downlink signal to a terminal through an unlicensed band and a case in which a terminal transmits an uplink signal to a base station through an unlicensed band are mixed and described. However, in the present disclosure, if the contents proposed for any one of the two cases are different, that is, the contents can be equally applied to the case in which a base station transmits a downlink signal to a terminal through an unlicensed band and the case in which a terminal transmits an uplink signal to a base station through an unlicensed band, or can be partially modified and applied to the cases. Therefore, detailed descriptions of downlink signal transmission and reception are omitted. Furthermore, in the present disclosure, a case in which one downlink data information (codeword or TB) or uplink data information is transmitted and received between a base station and a terminal is assumed and described. However, the contents proposed in the present disclosure can also be applied to a case in which a base station transmits a downlink signal to a plurality of terminals, or a case in which a plurality of codewords or TBs are transmitted and received between a base station and a terminal.

[0310] A transmission node (hereinafter, referred to as a base station of a terminal) which attempts to transmit a signal through an unlicensed band can determine a channel access procedure method based on a type of a signal to be transmitted. For example, if the base station attempts to transmit a downlink signal including a PDSCH through an unlicensed band, the base station can perform a channel access procedure using a type 1 method. In addition, if the base station attempts to transmit a downlink signal not including a PDSCH through an unlicensed band, for example, if the base station attempts to transmit a synchronization signal or a PDCCH, the base station can perform a channel access procedure using a type 2 method, and can transmit a downlink signal not including a PDSCH.

[0311] In this case, the base station or the terminal can determine a channel access procedure method based on a transmission length of a signal to be transmitted through an unlicensed band or a length of a time or interval in which an unlicensed band is occupied and used. Generally, a channel access procedure using a type 1 method can require a longer time to be performed than a channel access procedure using a type 2 method. Accordingly, if a signal is to be transmitted within a short time interval or a reference time (e.g., X ms or Y symbols) or shorter, the base station or the terminal can perform a channel access procedure using a type 2 method. In contrast, if a signal is to be transmitted within a long time interval or a time greater than a reference time (e.g., X ms or Y symbols) or a reference time or longer, the base station or the terminal can perform a channel access procedure using a type 1 method. In other words, a channel access procedure using different methods can be performed based on a time in which an unlicensed band is used.

[0312] If the base station or the terminal performs a channel access procedure using a type 1 method based on at least one reference, the base station or the terminal can determine a channel access priority class (CAPC) based on a quality of service class identifier (QCI) of a signal to be transmitted through an unlicensed band, and can perform a channel access procedure by using at least one value among configuration values regarding the CAPC as pre-defined in Table 20. For example, QCI 1, 2, and 4 can respectively represent QCI values of services, e.g., conversational voice, conversational video (live streaming), and non-conversational video (buffered streaming). If a signal of a service not matching the QCI in Table 20 is to be transmitted through an unlicensed band, the base station or the terminal can select a QCI closest to the service and the QCI in Table 20, and can select a CAPC thereof.

[0313] Table 20 shows a mapping relationship between the CAPC and the QCI.

[0314] [Table 20]

[0315] Channel access priority QCI 1 1，3，5，65，66，69，70 2 2，7 3 4，6，8，9 4 -

[0316] For example, through Table 21, the base station or the terminal can determine the delay duration according to the determined channel access priority p, the set of contention window values or size (CW_p), the minimum and maximum values of the contention window (CW_min,p, CW_max,p), the maximum channel occupancy time (T_mcot,p), etc. In other words, the base station attempting to transmit a downlink signal through the unlicensed band can perform a channel access procedure on the unlicensed band for at least the time of T_f + m_p*T_sl. If the base station attempts to perform a channel access procedure based on CAPC 3 (p=3), the size of the delay duration necessary to perform a channel access procedure by using m_p=3 can be determined as T_f + m_p*T_sl. If it is determined that the unlicensed band is in an idle state for the entire time of m_p*T_sl, N=N-1 can be caused. In this case, N can be selected as an arbitrary integer value between 0 and the value of the contention window (CW_p) in which the channel access procedure timing is performed. In the case of CAPC 3, the minimum contention window value and the maximum contention window value are 15 and 63, respectively. If it is determined that the unlicensed band is in an idle state for the delay duration and the duration in which an additional channel access procedure is performed, the base station can transmit a signal through the unlicensed band for the time T_mcot,p (8 ms). Meanwhile, Table 21 is a table indicating the CAPC in the downlink. For ease of description, the present disclosure will be described by using the downlink CAPC. However, in the case of the uplink, the CAPC in Table 21 can be reused, or a CAPC for uplink transmission can be defined and used.

[0317] [table 21]

[0318]

[0319] Meanwhile, the base station can configure the terminal by using a table through higher layer signaling (e.g., SIB, MIB, MAC-CE, or RRC signaling) necessary for the channel access procedure execution information of the uplink transmission of the terminal. Each column in the table can include at least one of the channel access procedure type, the CAPC, the cyclic prefix (CP) extension value of the uplink (or downlink) OFDM symbol transmission, or the timing advance (TA) value. For example, if the base station indicates the uplink transmission of the terminal as DCI format 0_0, by using the 2-bit field "ChannelAccess-CPext" included in the corresponding DCI format, the base station can indicate the information necessary for the channel access procedure and the uplink transmission of the terminal to the terminal corresponding to the column of Table 22.

[0320] [table 22]

[0321] Bit field mapped to index Channel access type CP extension 0 Type 3 C2*symbol length-16us-TA 1 Type 2 C3*symbol length-25us-TA 2 Type 2 C1*symbol length-25us 3 Type1 0

[0322] When the base station indicates the uplink transmission of the terminal as the DCI format 0_1, the base station can indicate the terminal of the information required for the channel access procedure and the uplink transmission by using the field "ChannelAccess_CPext" included in the corresponding DCI format and Table 23.

[0323] [Table 23]

[0324] Entry index Channel access type CP extension CAPC 0 Type3 0 1 1 Type3 0 2 2 Type3 0 3 3 Type3 0 4 4 Type3 C2*symbol length-16us-TA 1 5 Type3 C2*symbol length-16us-TA 2 6 Type3 C2*symbol length-16us-TA 3 7 Type3 C2*symbol length-16us-TA 4 8 Type2 with 16us 0 1 9 Type2 with 16us 0 2 10 Type2 with 16us 0 3 11 Ttpe2 with 16us 0 4 12 Type2 with 16us C2*symbol length-16us-TA 1 13 Type2 with 16us C2*symbol length-16us-TA 2 14 Type2 with 16us C2*symbol length-16us-TA 3 15 Type2 with 16us C2*symbol length-16us-TA 4 16 Type2 with 25us 0 1 17 Type2 with 25us 0 2 18 Type2 with 25us 0 3 19 Type2 with 25us 0 4 20 Type2 with 25us 1*symbol length-25us 1 21 Type2 with 25us 1*symbol length-25us 2 22 Type2 with 25us 1*symbol length-25us 3 23 Type2 with 25us 1*symbol length-25us 4 24 Type2 with 25us C3*symbol length-25us-TA 1 25 Type2 with 25us C3*symbol length-25us-TA 2 26 Type2 with 25us C3*symbol length-25us-TA 3 27 Type2 with 25us C3*symbol length-25us-TA 4 28 Type1 0 1 29 Type1 0 2 30 Type1 0 3 31 Type1 0 4 32 Type1 1* symbol length - 25 us 1 33 Type1 1* symbol length - 25 us 2 34 Type1 1* symbol length - 25 us 3 35 Type1 1* symbol length - 25 us 4 36 Type1 C2* symbol length - 16 us - TA 1 37 Type1 C2* symbol length - 16 us - TA 2 38 Type1 C2* symbol length - 16 us - TA 3 39 Type1 C2* symbol length - 16 us - TA 4 40 Type1 C3* symbol length - 25 us - TA 1 41 Type1 C3* symbol length - 25 us - TA 2 42 Type1 C3* symbol length - 25 us - TA 3 43 Type1 C3* symbol length - 25 us - TA 4

[0325] The base station can configure at least one entry in the column of Table 23 for the terminal through higher layer signaling. The terminal can receive the indication of one of the at least one entry in Table 23 configured by the base station through the field "ChannelAccess_CPext" from the base station. In this case, the size of the field "ChannelAccess_CPext" is determined as I denotes the number of entries configured by the base station through higher layer signaling.

[0326] The initial contention window value (CW_p) is the minimum value (CW_min,p) of the contention window. The base station having selected the N value can perform the channel access procedure at intervals of T_sl; if it is determined through the channel access procedure performed at intervals of T_sl that the unlicensed band is in an idle state, the N value can be changed to N = N - 1; and when N = 0, a signal can be transmitted through the unlicensed band for a maximum time of T_mcot,p. If it is determined through the channel access procedure that the unlicensed band is not in an idle state for a time of T_sl, the base station can perform the channel access procedure again without changing the N value.

[0327] The value of the contention window (CW_p) can be changed based on the reception result of the PDSCH in the reference subframe or the reference time slot in the timing at which the base station initiates the channel access procedure, the timing at which the base station selects the N value to perform the channel access procedure, or the downlink signal transmission interval (or MCOT) most recently transmitted through the unlicensed band just before the timing. In other words, the base station can receive a report of the reception result of the downlink data transmitted in the reference subframe or the reference time slot from the terminal, and can increase or decrease the size of CW_p based on the ratio Z of NACKs in the reception result.

[0328] Figure 10 FIG. 1 is a diagram illustrating an example of a method of determining a contention window (CW_p) according to an embodiment of the disclosure.

[0329] Figure 10The first transmission interval 1040 (hereinafter referred to as a subframe-to-slot) of the downlink signal transmission interval 1030 most recently transmitted before the timing at which the base station initiates the channel access procedure 1002, the timing at which the base station selects the N value to perform the channel access procedure, or the timing just before the timing becomes the contention window change reference slot of the channel access procedure 1002. If the base station cannot receive a report of the reception result of the PDSCH transmitted in the first slot 1040 of the transmission interval 1030, for example, if the time interval between the first subframe and the timing at which the base station initiates the channel access procedure 1002 is equal to or less than n slots or subframes, i.e., if the base station initiates the channel access procedure before the terminal can report the PDSCH reception result for the first subframe 1040, the first subframe of the downlink signal transmission interval most recently transmitted before the downlink signal transmission interval 1030 becomes the reference subframe. In other words, at the timing at which the base station initiates the channel access procedure 1002, at the timing at which the base station selects the N value to perform the channel access procedure, or at the timing just before the timing, if the base station does not receive the reception result of the downlink data transmitted in the reference subframe 1040 from the terminal, the base station can determine the first subframe of the downlink signal transmission interval most recently transmitted as the reference subframe from among the PDSCH reception results previously received from the terminal. Furthermore, the base station can determine the contention window size for the channel access procedure 1002 by using the downlink data reception result for the downlink data transmitted through the PDSCH in the reference subframe received from the terminal.

[0330] For example, if it is determined that 80% or more of the reception results of the terminal in the reception results for the downlink data that has been transmitted to the terminal through the PDSCH in the first subframe among the downlink signals transmitted through the unlicensed band are NACKs, the base station that has transmitted the downlink signal according to the channel access procedure configured based on the CAPC 3 (p=3) (e.g., CW_p=15) can increase the contention window from the initial value (e.g., CW_p=15) to the next contention window value (e.g., CW_p=31).

[0331] If it is determined that 80% or more of the reception results of the terminal are not NACKs, the base station can maintain the value of the contention window as the existing value, or can change the value of the contention window to the initial value of the contention window. In this case, the change of the contention window can be commonly applied to all common CAPCs, or can be applied only to the CAPC used in the channel access procedure. In this case, the method of determining the reception results effective at the time of the change of the contention window size from among the reception results transmitted from or reported to the base station for the downlink data transmitted through the PDSCH in the reference subframe or the reference slot for determining the change of the contention window size, in other words, the method of determining the Z value is as follows.

[0332] If the base station has transmitted one or more codewords or TBs to one or more terminals in the reference subframe or reference time slot, the base station can determine the Z value as a ratio of NACKs in reception results of the TBs received by the terminal in the reference subframe or reference time slot. For example, if two codewords or two TBs have been transmitted to one terminal in the reference subframe or reference time slot, the base station receives a report of reception results of downlink data signals for the two TBs from the terminal. If a ratio Z of NACKs in the two reception results has been defined previously or is greater than or equal to a threshold value configured between the base station and the terminal (for example, Z = 80%), the base station can change or increase the size of the contention window.

[0333] In this case, if the terminal bundles downlink data reception results of one or more subframes (for example, M subframes) including the reference subframe or time slot, and the downlink data reception results are transmitted to or reported to the base station, the base station can determine that the terminal has transmitted M reception results. In addition, the base station can determine the Z value as a ratio of NACKs in the M reception results, and can change, maintain, or initialize the size of the contention window.

[0334] If the reference subframe is a reception result of the second time slot in two time slots constituting one subframe, the base station can determine the Z value as a ratio of NACKs in reception results of the reference subframe (in other words, the second time slot) and downlink data received in the next subframe, which are transmitted to or reported to the base station from the terminal.

[0335] In addition, in a case where scheduling information or downlink control information for a PDSCH transmitted by the base station is transmitted in the same cell or frequency band as a cell or frequency band in which the PDSCH is transmitted, or in a case where the scheduling information or downlink control information for the PDSCH transmitted by the base station is transmitted through an unlicensed frequency band, or transmitted in a different cell from a cell in which the PDSCH is transmitted, or transmitted at a different frequency, if it is determined that the terminal does not transmit reception results of downlink data received in the reference subframe or reference time slot and if the reception results of the downlink data transmitted by the terminal are determined as DTX, or NACK / DTX, or any state, the base station can determine the Z value by determining the reception results of the terminal as NACK.

[0336] In addition, in a case where the scheduling information or downlink control information for the PDSCH transmitted by the base station is transmitted through a licensed frequency band, if the reception results of the downlink data transmitted by the terminal are determined as DTX, or NACK / DTX, or any state, the base station can not include the reception results of the terminal in the reference value Z for contention window change. In other words, the base station can ignore the reception results transmitted or reported by the terminal, and can determine the Z value.

[0337] In addition, in a case where the base station transmits scheduling information or downlink control information for a PDSCH through a licensed band, if there is no transmission of downlink data from the terminal to the base station in a reception result of downlink data transmitted or reported from the terminal to the base station in a reference subframe or a reference slot, the base station can ignore the reception result of the downlink data transmitted or reported by the terminal, and can determine a Z value.

[0338] Meanwhile, when the base station and the terminal transmit and receive a signal having directivity (for example, beam-based signal transmission), if the base station and the terminal perform the above-described channel access procedure for all directions, a transmission occasion can be reduced due to the performance of unnecessary channel access procedures. Accordingly, the disclosure proposes a method and apparatus capable of improving a channel access occasion by performing a channel access procedure based on directivity information by the base station and the terminal.

[0339] The wireless communication system, and the method and apparatus proposed in the embodiments of the disclosure have been described based on an NR system, but the content of the disclosure is not limited to the NR system, and can be applied to various wireless communication systems such as LTE, LTE-A, LTE-A-Pro, and 5G. In addition, the content in the disclosure is described based on a system and apparatus that transmits and receives a signal by using an unlicensed band, but the content of the disclosure can also be applied to a system operating in a licensed band. In addition, in the embodiments of the disclosure, it will be assumed and described that a base station and a terminal operating in an unlicensed band, but the method and apparatus proposed in the embodiments of the disclosure can also be applied to a base station and a terminal operating in a licensed band or a shared spectrum or a sidelink in addition to an unlicensed band.

[0340] Hereinafter, in the disclosure, higher layer signaling or a higher layer signal is a method of transmitting a signal that is transmitted from a base station to a terminal by using a downlink data channel of a physical layer or a signal that is transmitted from a terminal to a base station by using a PUSCH of a physical layer, and includes a method of transmitting a signal through RRC signaling or PDCP signaling or a MAC control element (MAC CE). In addition, the higher layer signaling or the higher layer signal can include system information commonly transmitted to a plurality of terminals, for example, a system information block (SIB).

[0341] Hereinafter, in embodiments of the disclosure, an arbitrary integer value N can represent an integer value arbitrarily selected in performing the aforementioned channel access procedure, between 0 and a value of a contention window (CW_p) timed in the aforementioned channel access procedure. Further, hereinafter, in embodiments, selecting an arbitrary integer value N can completely include selecting a common value N for the channel access procedure, selecting N1, N2, and N3 values individually for each channel access procedure, or selecting a common value for some of the N1, N2, and N3 values and selecting values individually for some other values of N1, N2, and N3. Further, hereinafter, in embodiments, three directions (or beams) are described as an example, but the number of directions (or beams) considered in performing the channel access procedure can be variously configured. Further, hereinafter, in embodiments, the same or similar contents as disclosed with respect to the channel access procedure and the downlink signal transmission method of the base station can also be applied to the channel access procedure and the uplink signal transmission of the terminal. Further, hereinafter, in embodiments, the same or similar contents as disclosed with respect to the channel access procedure and the uplink signal transmission method of the terminal can also be applied to the channel access procedure and the uplink signal transmission of the base station. Further, hereinafter, embodiments can be combined and used.

[0342] [Embodiment 1]

[0343] The present embodiment proposes a method of performing a channel access procedure by a base station and a UE operating in an unlicensed band. More specifically, the base station and the UE can perform a channel access procedure on a specific direction (or beam) on which a signal is to be transmitted. Figure 11 is a diagram illustrating a method of performing a channel access procedure by a base station and a UE according to an embodiment of the disclosure. Hereinafter, the description is made with reference to Figure 11 is given. The base station (or UE 1100) can perform a channel access procedure for each specific direction (or beam) 1110, 1111, or 1112. In this case, the base station (or UE) can select an arbitrary integer value N (N1, N2, or N3) 1101, 1102, or 1103 for performing a channel access procedure for each specific direction (or beam) 1110, 1111, or 1112. The method of configuring and determining the specific direction (or beam) by the base station and the UE is described in detail.

[0344] [Embodiment (1-1)]

[0345] The base station and the UE can configure a spatial domain reception filter (or spatial Rx filter) based on a spatial domain transmission filter (or spatial Tx filter) configured to transmit a signal in a specific direction (hereinafter referred to as a beam). The base station and the UE can perform a channel access procedure for each configured reception filter (or transmission filter). In this case, the base station and the UE can select an arbitrary integer value N for performing the channel access procedure for each reception filter (or transmission filter).

[0346] <Embodiment (1-2)>

[0347] The base station can select an arbitrary integer value N for performing a channel access procedure for each SSB index. The base station can configure a spatial domain reception filter based on a spatial domain transmission filter configured to transmit an SSB. The base station can select an arbitrary integer value N for each configured reception filter (or transmission filter) and can perform a channel access procedure. If the base station transmits a plurality of SSBs in the same direction or applies the same spatial domain transmission filter to a plurality of SSBs, only one arbitrary integer value N can be selected for a plurality of corresponding SSB indices.

[0348] <Embodiment (1-3)>

[0349] The base station can select an arbitrary integer value N for performing a channel access procedure for each TCI state (or TCI state index (ID)). The base station can perform a channel access procedure for each ID of a type D in a TCI state for which a QCL type has been configured through higher layer signaling. In this case, the base station can configure a spatial domain reception filter based on a spatial domain transmission filter configured to transmit a reference signal configured in each TCI state. The base station can select an arbitrary integer value N for each configured reception filter (or transmission filter) and can perform a channel access procedure. Meanwhile, the base station can configure a separate TCI state ID for a UE to perform a beam-based channel access procedure through higher layer signaling. If the base station configures a reference signal having the same spatial domain transmission configuration in a plurality of TCI state indices, only one arbitrary integer value N can be selected for a plurality of corresponding TCI state indices.

[0350] <Embodiment (1-4)>

[0351] The base station can select an arbitrary integer value N for performing a channel access procedure for each spatial relation information index configured for PUCCH transmission of the UE. The base station can configure a reception filter based on a spatial domain transmission filter configured to transmit a reference signal configured in each PUCCH spatial relation information. The base station can select an arbitrary integer value N for each configured reception filter (or transmission filter) and can perform a channel access procedure. In addition, the base station can perform the aforementioned channel access procedure for each PUCCH resource or each PUCCH resource set.

[0352] <Embodiment (1-5)>

[0353] The base station and the UE can select an arbitrary integer value N for performing the channel access procedure for each SRS resource index. The base station and the UE can configure a spatial domain reception filter based on a spatial domain transmission filter configured to transmit a reference signal referred to by the spatial relation information configured in the SRS resource. The base station can select an arbitrary integer value N for each configured reception filter (or transmission filter), and can perform the channel access procedure. If the base station refers to a reference signal having the same spatial domain transmission configuration for multiple SRS resource indexes, only one arbitrary integer value N can be selected for the multiple corresponding SRS resource indexes. As another method, the base station can separately configure SRS spatial relation information for the UE through higher layer signaling. In this case, the base station can perform the channel access procedure according to the above-described method for each SRS spatial relation information index.

[0354] [Embodiment 2]

[0355] The present embodiment proposes a method of performing a channel access procedure by a base station and a UE operating in an unlicensed band. More specifically, the base station and the UE can perform a channel access procedure in a specific direction of a transmitted signal. If, as a result of the channel access procedure, it is determined that a frequency band (or a direction of a beam) is a free frequency band (or a direction of a beam), the base station and the UE can perform transmission in the corresponding frequency band (or direction of a beam). In addition, the UE can transmit an uplink signal in the direction of the frequency band (or beam direction) obtained by the base station. In this case, by considering the frequency band (or beam direction) obtained by the base station and the frequency band (or beam direction) in which the UE is to transmit an uplink signal, the UE can determine a channel access procedure to be performed to transmit the uplink signal. Detailed methods of the channel access procedure are provided below.

[0356] <Embodiment (2-1)>

[0357] When the uplink transmission of the UE is scheduled, the base station can transmit the DCI to the UE, which schedules the uplink transmission by including the TCI state indicator in the DCI. If the TCI state indicator (or the DCI) is valid information, the UE can determine the channel access procedure with reference to the reference signal configured in the TCI state received from the base station. The UE can configure the spatial domain transmission filter based on the spatial domain reception filter that has been used to receive the reference signal configured in the TCI state. In this case, if the UE transmits the uplink signal by using the spatial domain transmission filter configured based on the spatial domain reception filter, the UE can omit (not perform) the channel access procedure and can transmit the uplink signal. Alternatively, if the UE transmits the uplink signal by using the spatial domain transmission filter configured based on the spatial domain reception filter, the UE can perform the channel access procedure only within a fixed interval (e.g., 25 µs) or a fixed time slot. Alternatively, after performing the channel access procedure indicated in the DCI, the UE can perform the uplink transmission in the corresponding direction (or beam).

[0358] <Embodiment (2-2)>

[0359] The base station can configure the spatial relation information of the SRS for the UE through higher layer signaling. In addition, the base station can activate some of the spatial relation information of the SRS configured for the UE through the MAC CE. Thereafter, the base station can transmit the uplink transmission scheduling DCI to the UE by including the SRS spatial relation information index value in the uplink transmission scheduling DCI. If the DCI received by the UE is determined to be valid DCI, the UE can configure the spatial domain transmission filter based on the spatial domain reception filter that has been used to receive the reference signal configured in the spatial relation information of the SRS. In this case, if the UE transmits the uplink signal by using the spatial domain transmission filter configured based on the spatial domain reception filter, the UE can omit (or not perform) the channel access procedure. Alternatively, if the UE transmits the uplink signal by using the spatial domain transmission filter configured based on the spatial domain reception filter, the UE can perform the channel access procedure only within a fixed time (e.g., 25 µs) or a fixed time slot. Alternatively, after performing the channel access procedure indicated in the DCI, the UE can perform the uplink transmission in the corresponding direction (or beam).

[0360] As yet another approach, the base station can transmit the uplink scheduling DCI by including the SRS resource ID in the uplink scheduling DCI. If the DCI received by the UE is determined to be a valid DCI, the UE can configure the spatial domain transmission filter based on the spatial domain reception filter that has been used to receive the reference signal referred by the SRS spatial relation information configured in the SRS resource ID included in the DCI. In this case, the UE can omit (or not perform) the channel access procedure if the UE transmits the uplink signal by using the spatial domain transmission filter configured based on the spatial domain reception filter. Alternatively, the UE can perform the channel access procedure only within a fixed interval (e.g., 25 µs) or a fixed time slot and then transmit the uplink signal if the UE transmits the uplink signal by using the spatial domain transmission filter configured based on the spatial domain reception filter. Alternatively, the UE can perform the uplink transmission on the corresponding direction (or beam) after performing the channel access procedure indicated in the DCI. If the SRS resource indicator indicates one or more SRS resources (e.g., if one or more PUSCH layers have been configured), the UE can assume the SRS resource having the lowest (or highest) index among the indicated SRS resources.

[0361] <Embodiment (2-3)>

[0362] The base station can configure one or more PUCCH spatial relation information for the UE through higher layer signaling (e.g., RRC). The base station can activate some of the PUCCH spatial relation information configured for the UE through a MAC CE. The base station can transmit the uplink transmission scheduling DCI to the UE by including the PUCCH spatial relation information index indicator in the uplink transmission scheduling DCI. If the DCI received by the UE is determined to be a valid DCI, the UE can configure the spatial domain transmission filter based on the spatial domain reception filter that has been used to receive the reference signal configured in the PUCCH spatial relation information. In this case, the UE can transmit the uplink signal by using the spatial domain transmission filter configured in the spatial domain reception filter. In this case, the UE can omit (or not perform) the channel access procedure. Alternatively, the UE can perform the channel access procedure only within a fixed time (e.g., 25 µs) or a fixed time slot if the UE transmits the uplink signal by using the spatial domain transmission filter configured in the spatial domain reception filter. Alternatively, the UE can perform the uplink transmission on the corresponding direction (or beam) after performing the channel access procedure indicated in the DCI.

[0363] As yet another method, the base station can configure the PUCCH spatial relation information for the UE by including the PUCCH spatial relation information in the PUCCH resource index or the PUCCH resource set index. The base station can include the PUCCH resource indicator in the uplink transmission scheduling DCI. If the DCI received by the UE is determined as a valid DCI, the UE can refer to the PUCCH spatial relation information configured in the PUCCH resource indicator (or PUCCH resource set) in the received DCI. The UE can configure the spatial domain transmission filter based on the spatial domain reception filter that has been used to receive the reference signal configured in the PUCCH spatial relation information. In this case, the UE can transmit the uplink signal by using the spatial domain transmission filter configured in the spatial domain reception filter. In this case, the UE can omit (or not perform) the channel access procedure. Alternatively, if the UE transmits the uplink signal by using the spatial domain transmission filter configured in the spatial domain reception filter, the UE can perform the channel access procedure only for a fixed time (e.g., 25 µs) or within a fixed time slot. Alternatively, after performing the channel access procedure indicated in the DCI, the UE can perform the uplink transmission on the corresponding direction (or beam). Meanwhile, the above-described PUCCH spatial relation information can be applied to the transmission of all uplink signals, or can be limited and applied only to some uplink signals (e.g., PUCCH transmission).

[0364] <Embodiment (2-4)>

[0365] When transmitting an uplink signal (or configured grant PUSCH), the UE can perform a channel access on a specific direction (or beam). In this case, the UE can refer to separate SRS spatial relation information configured through higher layer signaling from the base station or SRS spatial relation information within an SRS resource. More specifically, the UE can perform a channel access procedure based on a spatial domain reception filter that has been used to receive a reference signal referred to by the SRS spatial relation information configured through higher layer signaling from the base station. In addition, the UE can transmit an uplink signal based on a corresponding spatial domain reception filter configuration. In this case, the UE can include an SRS spatial relation information indicator (or SRS resource indicator) assumed when performing a channel access procedure in uplink control information. The uplink control information can be transmitted by being included in a PUCCH or a PUSCH. If the base station that has received the SRS spatial relation information indicator (or SRS resource indicator) from the UE transmits a downlink by using a spatial domain transmission filter used to transmit a reference signal referred to by the corresponding SRS spatial relation information, the base station can omit (or not perform) a channel access procedure. Alternatively, if the base station transmits a downlink by using a spatial domain transmission filter used to transmit a reference signal referred to by the corresponding SRS spatial relation information, the base station can perform a channel access procedure only for a fixed time (e.g., 25 µs) or within a fixed time slot. Meanwhile, in the above-described case, if the base station omits (or does not perform) a channel access procedure or performs a channel access procedure only for a fixed time (or a fixed time slot) based on information received from the UE, the base station can omit (or not perform) a channel access procedure only for a maximum channel occupancy interval obtained by the UE or omit (or not perform) a channel access procedure only for a fixed time (or a fixed time slot). In addition, if the base station omits (or does not perform) a channel access procedure or performs a channel access procedure only for a fixed time (or a fixed time slot) based on the SRS spatial relation information indicated by the UE, when the base station receives a shared indicator indicating that a channel obtained by the UE is shared with the base station from the UE, the base station can omit (or not perform) a channel access procedure or can perform a channel access procedure only for a fixed time (or a fixed time slot). In addition, the maximum channel occupancy interval and the shared indicator of the UE can be indicated to the base station through uplink control information.

[0366] <Embodiment (2-5)>

[0367] The base station can transmit a beam sharing indicator to the UE by including the beam sharing indicator in uplink scheduling DCI. The UE that has received the beam sharing indicator can share a beam obtained by the base station through the use of the above-described method.

[0368] In the present embodiment, as an example of a method of determining valid DCI, when the interval between the symbol at which the PDCCH including the DCI is transmitted and the downlink (or uplink) starting symbol scheduled by the PDCCH is greater than a given symbol (e.g., a time duration for QCL) or a given time value, the corresponding DCI can be determined as valid DCI. If the DCI received by the UE is not determined as valid DCI, the UE (or base station) can discard (or omit to delay) the uplink (or downlink) signal, or can perform a channel access procedure and then transmit the uplink (or downlink) signal. In this case, the channel access procedure can be performed in a different beam (or direction of the entire direction) from the corresponding beam (or direction). The base station (or UE) can indicate the corresponding channel access procedure through the DCI, can configure the corresponding channel access procedure through higher layer signaling, or can determine the corresponding channel access procedure in advance. In addition, the base station (or UE) can perform the channel access procedure (e.g., a Type 1 channel access procedure) in a variable time.

[0369] [Embodiment 3]

[0370] The present embodiment proposes a method of performing a channel access procedure by a base station and a UE operating in an unlicensed band. More specifically, the base station can perform a channel access procedure in a specific direction (or beam) in which a signal is to be transmitted. The base station can perform a channel access procedure in a plurality of directions (or beams). In this case, a method of selecting an arbitrary integer value N from among a plurality of directions (or a plurality of beams) and performing a channel access procedure is proposed.

[0371] <Embodiment (3-1)>

[0372] The base station can select an arbitrary integer value N for each specific direction (or beam) in which a signal is to be transmitted. A method of performing a channel access procedure by the base station based on the arbitrary integer value N selected for each beam (or direction) is proposed below.

[0373] [Method 1]

[0374] When all of the arbitrary integer values N respectively selected from one or more beams (or a plurality of directions) in which a signal is to be transmitted become 0, the base station can determine that the one or more beams (or a plurality of directions) are a free band (or a direction of a beam) as a result of a channel access procedure, and can perform downlink transmission.

[0375] Figure 12a FIG. 1 is a diagram illustrating a method of performing a channel access procedure by a base station and a UE according to an embodiment of the disclosure. Referring to FIG. 1, a base station and a UE can perform a channel access procedure in a specific direction (or beam) in which a signal is to be transmitted. Figure 12aThe method is described. The base station can select an arbitrary integer N for each of beams #1 to #3 (1201, 1202, and 1203) performing a channel access procedure as N1210, N1211, and N31212, respectively. If beam #1 1201 is determined as a free beam (or band, direction) as a result of base station channel sensing, the base station can change N1 of beam #1 1201 as N1=N1-1. The base station can apply the same method for each beam. When all N1, N2, and N3 values become 0, the base station can transmit a downlink signal by using beams #1 to #3 (1201, 1202, and 1203). As another method, when the N value becomes 0 in at least one direction (or beam), the base station can perform downlink transmission in the one or more directions (or beams) in which the N value becomes 0. For example, the base station can select an arbitrary integer N for each of beams #1 to #3 (1201, 1202, and 1203) performing a channel access procedure as each of N1210, N1211, and N31212. If beam #1 1201 is determined as a free beam (or band, direction) as a result of base station channel sensing, the base station can change N1 of beam #1 1201 as N1=N1-1. The base station can apply the same method for each beam. In this case, when at least one of N1, N2, and N3 values becomes 0 (e.g., N1=0), the base station can transmit a downlink signal by using the corresponding beam (e.g., beam #1). In this case, the base station can not transmit a signal in beam #2 and beam #3, and can maintain the N2 value of beam #2 and the N3 value of beam #3.

[0376] [Method 2]

[0377] The base station can select an arbitrary integer value N for each of one or more beams (or directions) in which a signal is to be transmitted. Next, the base station can configure a maximum (or minimum) N value among the selected arbitrary integer values selected for the one or more beams (or directions) in each beam (or direction). For example, this will be described below with reference to Figure 12a The base station can select an arbitrary integer for beam #1, beam #2, and beam #3 as N1, N2, and N3, respectively. When the N1 value is the maximum, the base station can configure the arbitrary integer values for beam #1, beam #2, and beam #3 as N1.

[0378] Thereafter, the base station can perform a channel access procedure in all directions (or beams). When all N (e.g., N1) values configured in all directions (or beams) become 0, the base station can determine all directions (or beam directions) as a free band (or beam direction) and perform downlink transmission. For example, when N1 value among N1, N2, and N3 selected for beam #1, beam #2, and beam #3 is the largest, any integer N of beam #1, beam #2, and beam #3 can be configured as N1, N1, and N1. If beam #1 is determined as a free beam (or band, direction) as a result of base station channel sensing, the base station can change N1 of beam #1 to N1=N1-1. The base station can apply the same method to each beam. When N1 values of all beams become 0, the base station can transmit a downlink signal by using beam #1, beam #2, and beam #3. As another method, when N (e.g., N1) value determined in at least one direction (or beam) becomes 0, the base station can perform downlink transmission only in one or more directions (or beams) in which N (e.g., N1) value becomes 0. For example, the base station can select any integer as N1, N1, and N1 for beam #1, beam #2, and beam #3, respectively. If beam #1 is determined as a free beam (or band to direction) as a result of base station channel sensing, the base station can change N1 of beam #1 to N1=N1-1. The base station can apply the same method to each beam. In this case, when at least one of N1 values of beams becomes 0 (e.g., N1 of beam #1 is 0), the base station can transmit a downlink signal by using the corresponding beam (e.g., beam #1). In this case, the base station can not transmit a signal in beam #2 and beam #3, and can maintain N1 values of beam #2 and beam #3.

[0379] <Embodiment (3-2)>

[0380] Figure 12b FIG. 12 is a diagram illustrating a method of performing a channel access procedure by a base station and a UE according to another embodiment of the disclosure. Hereinafter, the method will be described with reference to FIG. 12. Figure 12b The method is described. The base station can constitute a specific direction (or beam) in which a signal is to be transmitted as one set 1221, 1222, and 1223. The base station can select an arbitrary integer value N from among beams (or directions) included in the one set 1230. In this case, if at least one beam within the constituted set is determined as a free direction (or beam, band) as a result of detection, the base station can change the N value to N=N-1. As another method, if all beams within the constituted set are determined as a free direction (or beam, band) as a result of detection, the base station can change the N value to N=N-1. When the N value becomes 0, the base station can perform downlink transmission in all beams within the constituted set.

[0381] Figure 13 FIG. 12 is a diagram illustrating operations of a base station according to an embodiment of the disclosure.

[0382] The operations of the base station according to an embodiment of the disclosure will be described below by using FIG. 12. Figure 13

[0383] In step 1300, the base station can transmit, to the UE, a configuration related to transmission and reception of a PDCCH, a PDSCH, a PUCCH, or a PUSCH through a higher layer signal. For example, the base station can transmit, to the UE, a PDCCH resource region or a CORESET configuration, a search space configuration, etc. for receiving downlink or uplink scheduling information through a higher layer signal. Also, the base station can transmit, to the UE, a configuration related to PDSCH / PUSCH transmission and reception including offset information between a PDCCH reception slot and a PDSCH reception slot or offset information between a PDCCH reception slot and a PUSCH transmission slot, PDSCH or PUSCH retransmission number information of the UE, etc. through a higher layer signal. Also, the base station can transmit, to the UE, a configuration related to a PUCCH resource or a PUCCH resource set and spatial relation information of a PUCCH through a higher layer signal. Also, the base station can further transmit configuration information related to a TCI state. In this case, the information transmitted to the UE in step 1310 can be transmitted in step 1300. In step 1320, when the base station performs a channel access procedure by including information in DCI, the base station can transmit, to the UE, information for configuring beam information. In step 1330, the base station can receive and decode an uplink in a beam direction configured for the UE.

[0384] Figure 14 FIG. 14 is a diagram illustrating operations of a UE according to an embodiment of the disclosure.

[0385] The operations of the UE according to an embodiment of the disclosure will be described below by using FIG. 14. Figure 14

[0386] ​​In step 1400, the UE receives, from the base station, configuration information related to transmission and reception of PDCCH, PDSCH, PUCCH, or PUSCH through a higher layer signal, and performs configuration related to transmission and reception of PDCCH, PDSCH, PUCCH, or PUSCH based on the received configuration information. For example, the UE can be configured with PDCCH resource region or CORESET configuration, search space configuration, etc. through which downlink or uplink scheduling information is received from the base station through a higher layer signal. In addition, the UE can receive, from the base station, configuration information related to transmission and reception of PDSCH / PUSCH through a higher layer signal, including offset information between a PDCCH reception time slot and a PDSCH reception time slot or offset information between a PDCCH reception time slot and a PUSCH transmission time slot, PDSCH or PUSCH retransmission number information of the UE, etc. In addition, the UE can be configured with configuration information related to PUCCH resource or PUCCH resource set and spatial relation information of PUCCH through a higher layer signal. In step 1410, the UE can also receive, from the base station, configuration information related to SRS resource or SRS resource set or spatial relation information of SRS. In addition, in step 1410, the UE can also receive configuration information related to TCI state. In step 1420, the UE can receive, from the base station, DCI indicating downlink reception or uplink transmission. If the DCI received by the UE in step 1430 includes information indicating that the base station has performed a channel access procedure in a direction (or beam) to a direction (or beam) in which the UE will transmit an uplink signal, the UE can transmit an uplink signal by using a corresponding beam without performing a channel access procedure in step 1450. If the DCI received by the UE in step 1430 does not include beam-related information for uplink transmission, the UE can perform a channel access procedure in step 1440, and can transmit or discard an uplink signal.

[0387] Figure 15 is a block diagram illustrating a structure of a base station according to an embodiment of the disclosure.

[0388] As Figure 15As illustrated, the base station of the disclosure can include a base station reception unit 1500, a base station transmission unit 1510, and a base station processor 1520. In the embodiments of the disclosure, the base station reception unit 1500 and the base station transmission unit 1510 are generally referred to as a transceiver unit. The transceiver unit can transmit and receive signals to and from the terminal. The signal can include control information and data. To this end, the transceiver unit can include an RF transmitter that up-converts and amplifies the transmitted signal in frequency, and an RF receiver that low-noise amplifies and down-converts the received signal, etc. Furthermore, the transceiver unit can receive a signal through a wireless channel, can output the signal to the base station processor 1520, and can transmit the signal output by the base station processor 1520 through a wireless channel. The base station processor 1520 can control a series of processes so that the base station can operate according to the above-described embodiments of the disclosure. For example, the base station processor 1520 can perform a channel access procedure on an unlicensed band. As a detailed example, the base station reception unit 1520 can receive a signal transmitted in an unlicensed band. The base station processor 1520 can determine whether the unlicensed band is in an idle state by comparing the received signal strength, etc. with a threshold value defined in advance or a value determined by using a function value with a bandwidth, etc. as a factor. In this case, the base station processor 1520 can perform a channel access procedure for each direction (or beam).

[0389] Figure 16 is a block diagram illustrating a structure of a terminal according to an embodiment of the disclosure.

[0390] As Figure 16As illustrated, the terminal of the disclosure can include a terminal reception unit 1600, a terminal transmission unit 1610, and a terminal processor 1620. In the embodiments of the disclosure, the terminal reception unit 1600 and the terminal transmission unit 1610 are generally referred to as a transceiver unit. The transceiver unit can transmit and receive signals to and from the base station. The signal can include control information and data. To this end, the transceiver unit can include an RF transmitter that up-converts and frequency-amplifies a transmission signal, and an RF receiver that low-noise-amplifies and down-converts a reception signal, etc. Further, the transceiver unit can receive a signal through a wireless channel, can output the signal to the terminal processor 1620, and can transmit a signal output by the terminal processor 1620 through a wireless channel. The terminal processor 1620 can control a series of processes so that the terminal can operate according to the above-described embodiments of the disclosure. For example, the terminal processor 1620 can perform a channel access procedure on an unlicensed band. As a detailed example, the terminal processor 1620 can receive a signal transmitted in an unlicensed band. The terminal processor 1620 can determine whether the unlicensed band is in an idle state by comparing a reception signal strength, etc. with a threshold value defined in advance or a value determined by using a function value with a bandwidth, etc. as a factor. In this case, the terminal processor 1620 can perform a channel access procedure for each direction (or beam).

Claims

1. A method for a user equipment (UE) in a communication system, the method comprising: Identify multiple beams used in the Type 1 channel access procedure; For each beam, identify the corresponding value N for the Type 1 channel access procedure, where N is an integer value between 0 and the contention window CW; and Based on the corresponding value N, the Type 1 channel access procedure is executed independently on each beam. The spatial filter for each beam is determined based on at least one of the following: The spatial filter associated with the indicated probe reference signal (SRS) resource indicator. Spatial filters associated with reference signals corresponding to SRS spatial relationship information configured in higher-layer signaling; or A spatial filter associated with a reference signal indicating the TCI state in the indicated transmission configuration.

2. The method according to claim 1, wherein, The plurality of beams used in the Type 1 channel access procedure are associated with a plurality of transmission beams.

3. The method according to claim 1, wherein, For each beam in the Type 1 channel access procedure, the value N is selected independently.

4. A user equipment (UE) in a communication system, comprising: transceiver; as well as The controller is configured as follows: Identify multiple beams used for Type 1 channel access procedures; For each beam, identify the corresponding value N for the Type 1 channel access procedure, where N is an integer value between 0 and the contention window CW; and Based on the corresponding value N, the Type 1 channel access procedure is executed independently on each beam. The spatial filter for each beam is determined based on at least one of the following: The spatial filter associated with the indicated probe reference signal (SRS) resource indicator. Spatial filters associated with reference signals corresponding to SRS spatial relationship information configured in higher-layer signaling; or A spatial filter associated with a reference signal indicating the TCI state in the indicated transmission configuration.

5. The UE according to claim 4, wherein, The plurality of beams used in the Type 1 channel access procedure are associated with a plurality of transmission beams.

6. The UE according to claim 4, wherein, For each beam in the Type 1 channel access procedure, the value N is selected independently.

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