Methods and apparatus for HARQ-ACK feedback in wireless communication systems

Abstract

A terminal for performing data transmission and reception in a wireless communication system is provided, wherein the terminal: receives from a base station first configuration information for uplink transmission based on code block groups (CBGs) and second configuration information including a downlink feedback information (DFI) bitmap configuration method; transmits CBG-based uplink signals to the base station based on the first configuration information; and receives from the base station, based on the second configuration information, DFI including feedback information regarding the CBG-based uplink signals, wherein the DFI bitmap configuration method indicates whether the feedback information is for feedback on a transport block (TB) basis or for feedback on one or more CBGs.

Description

Technical Field

[0001] This disclosure relates to a method and apparatus for feedback of Hybrid Automatic Repeat Request-Acknowledgement (HARQ-ACK) in a wireless communication system. More specifically, this disclosure relates to a method by which a wireless communication system, particularly a system and node for receiving uplink signals or transmitting downlink signals in an unlicensed frequency band, sends information indicating uplink signal decoding failure or success to a system and node attempting to transmit uplink signals. Background Technology

[0002] To meet the significantly increased demand for wireless data traffic due to the commercialization of fourth-generation (4G) communication systems and the rise of multimedia services, evolved fifth-generation (5G) systems, or pre-5G communication systems, have been developed. For this reason, 5G or pre-5G communication systems are referred to as "beyond 4G network communication systems" or "post-Long Term Evolution (LTE) systems."

[0003] To improve data rates, 5G communication systems are being considered for implementation in the ultra-high frequency band (millimeter wave (mmW)) (e.g., 60 GHz). To reduce propagation path loss and increase propagation distance of radio waves in the millimeter wave band, technologies such as beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO are being discussed in 5G communication systems.

[0004] Furthermore, to improve system networks, technologies such as Evolved Small Cell, Advanced Small Cell, Cloud Radio Access Network (Cloud RAN), Ultra-Dense Network, Device-to-Device (D2D) Communication, Wireless Backhaul, Mobile Network, Cooperative Communication, Cooperative Multipoint (CoMP), and Receiver Interference Cancellation have been developed for 5G communication systems. Additionally, advanced coding and modulation (ACM) technologies such as Hybrid Frequency Shift Keying (FSK), Quadrature Amplitude Modulation (QAM) (FQAM), and Sliding Window Overlay Coding (SWSC) have been developed for 5G communication systems, as well as advanced access technologies such as Filter Bank Multicarrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA).

[0005] The internet is evolving from a human-centric network of connections where humans can create and consume information to an Internet of Things (IoT) network, where distributed elements such as objects can exchange and process information. The Internet of Everything (IoE) technology, which combines IoT technology with big data processing technology through connection to cloud servers, is also emerging. To realize IoT, technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required. Therefore, technologies for inter-object connectivity, such as sensor networks, machine-to-machine (M2M) communication, or machine-type communication (MTC), have recently been researched. In the IoT environment, intelligent internet technology (IT) services can be provided, collecting and analyzing data generated by connected objects and creating new value in human life. Through the convergence and integration of existing information technology (IT) and various industrial applications, IoT can be applied to a wide range of fields, such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0006] Various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, M2M communication, or MTC are being implemented using 5G communication technologies such as beamforming, MIMO, or array antennas. Cloud RAN, as an application of big data processing technology, can also be considered an example of the integration of 5G and IoT technologies. Summary of the Invention

[0007] Technical issues

[0008] This disclosure provides a method and apparatus for feeding back Hybrid Automatic Repeat Request-Acknowledgement (HARQ-ACK) in a wireless communication system.

[0009] Solution to the problem

[0010] According to embodiments of this disclosure, a terminal is provided that receives from a base station first configuration information for uplink transmission based on code block groups (CBGs) and second configuration information including a downlink feedback information (DFI) bitmap configuration method, transmits CBG-based uplink signals to the base station based on the first configuration information, receives DFI including feedback information about the CBG-based uplink signals from the base station based on the second configuration information, and determines a contention window value for the terminal based on the feedback information included in the received DFI.

[0011] The beneficial effects of openness

[0012] According to embodiments of this disclosure, hybrid automatic repeat request-acknowledgment (HARQ-ACK) feedback can be sent or received more efficiently in a wireless communication system. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating the structure of uplink / downlink time-frequency domain transmission in a New Radio (NR) system.

[0014] Figure 2 It is a diagram used to describe the channel access process in unlicensed frequency bands.

[0015] Figure 3 This is a diagram illustrating downlink or uplink scheduling methods and resource areas in an NR system.

[0016] Figure 4 This is a diagram illustrating downlink or uplink scheduling methods and resource areas in an NR system.

[0017] Figure 5 This is a diagram illustrating an embodiment of the present disclosure.

[0018] Figure 6 This is a diagram illustrating another embodiment of the present disclosure.

[0019] Figure 7 This is a diagram illustrating another embodiment of the present disclosure.

[0020] Figure 8 This is a flowchart illustrating the operation of a base station according to an embodiment of the present disclosure.

[0021] Figure 9 This is a flowchart illustrating the operation of a terminal according to an embodiment of the present disclosure.

[0022] Figure 10 This is a block diagram illustrating the structure of a base station according to an embodiment of the present disclosure.

[0023] Figure 11 This is a block diagram illustrating the structure of a terminal according to an embodiment of the present disclosure. Detailed Implementation

[0024] According to embodiments of this disclosure, a method for a terminal to perform data and feedback transmission and reception in a wireless communication system includes: a base station sending downlink feedback information (DFI) to determine relevant information; the base station configuring a DFI bitmap; the terminal receiving the DFI from the base station to determine the relevant information; and in response to receiving the DFI from the base station based on the configured DFI to determine the relevant information, the terminal decoding the DFI bitmap and controlling retransmission and contention window values.

[0025] According to embodiments of this disclosure, a terminal in a wireless communication system for performing data transmission and reception includes: a transceiver; and at least one processor configured to: receive from a base station first configuration information for uplink transmission based on code block groups (CBGs), and second configuration information including a downlink feedback information (DFI) bitmap configuration method; transmit CBG-based uplink signals to the base station based on the first configuration information; receive from the base station, based on the second configuration information, a DFI including feedback information regarding the CBG-based uplink signals; and determine a contention window value for the terminal based on the feedback information included in the received DFI. The DFI bitmap configuration method can indicate whether the feedback information is for feedback on a transport block (TB) basis or for feedback on one or more CBGs.

[0026] The CBG-based uplink signal may include one or more uplink signals transmitted in a first time slot, wherein the at least one processor may further be configured to: identify feedback information included in the received DFI as feedback information in TB units based on second configuration information; determine a contention window value as a first contention window value or maintain the current contention window value when at least one of the multiple feedback messages regarding the one or more uplink signals transmitted in the first time slot is an acknowledgment (ACK); and determine a contention window value as a second contention window value when all feedback messages regarding the one or more uplink signals transmitted in the first time slot are negative acknowledgments (NACKs). The current contention window value may be equal to or greater than the first contention window value, and equal to or less than the second contention window value.

[0027] The at least one processor may also be configured to: identify feedback information included in the received DFI as feedback information in units of CBG based on second configuration information; determine feedback information of CBG for each of the multiple time slots based on the feedback information included in the received DFI; determine the ratio of ACK and NACK in units of CBG for a reference time slot included in the multiple time slots based on the determined feedback information of CBG for each of the multiple time slots; and change or maintain the contention window value based on the determined ratio.

[0028] The feedback information included in the DFI may include feedback information about one or more CBG-based uplink signals transmitted in the first time slot, wherein the feedback information about one or more CBG-based uplink signals transmitted in the first time slot may be independent of the retransmission of one or more CBG-based uplink signals transmitted in the first time slot, and may be used to determine the contention window value of the terminal.

[0029] The at least one processor may also be configured to: receive uplink (UL) licensed downlink control information (DCI) from a base station, the UL licensed DCI information including feedback information in TB or CBG units regarding CBG-based uplink signals; determine whether the feedback information included in the received DFI and the feedback information included in the UL licensed DCI are the same; and when the feedback information included in the received DFI and the feedback information included in the UL licensed DCI are different from each other, determine a contention window value for the terminal based on at least one of the feedback information included in the received DFI and the feedback information included in the UL licensed DCI.

[0030] The feedback information included in the DFI may include feedback information about one or more CBG-based uplink signals transmitted in a first time slot corresponding to a reference time slot. The at least one processor may also be configured to receive from the base station a UL-licensed DCI including feedback information in TB or CBG units about the CBG-based uplink signals. The UL-licensed DCI may be used to determine the contention window value of the terminal when the UL-licensed DCI is received before the DFI, or when the first time slot is a reference time slot after the UL-licensed DCI is received and no other uplink signal is transmitted after the DFI is received.

[0031] CBG-based uplink signals may include uplink signals scheduled by the base station.

[0032] According to another embodiment of this disclosure, a base station in a wireless communication system for performing data transmission and reception includes: a transceiver; and at least one processor configured to: send to a terminal first configuration information for uplink transmission based on code block groups (CBGs), and second configuration information including a downlink feedback information (DFI) bitmap configuration method; receive CBG-based uplink signals from the terminal based on the first configuration information; decode the received CBG-based uplink signals on a CBG basis based on the second configuration information; and, based on the decoding result, send to the terminal a DFI including feedback information about the CBG-based uplink signals, wherein the DFI is used to determine a contention window value for the terminal, and the DFI bitmap configuration method indicates whether the feedback is in units of transport blocks (TBs) or feedback for one or more CBGs.

[0033] The feedback information included in the DFI may include feedback information about one or more CBG-based uplink signals transmitted in the first time slot, wherein the feedback information about one or more CBG-based uplink signals transmitted in the first time slot may be independent of the retransmission of one or more CBG-based uplink signals transmitted in the first time slot, and may be used to determine the contention window value of the terminal.

[0034] The at least one processor may also be configured to send uplink (UL) authorized downlink control information (DCI) to the terminal, the UL authorized DCI including feedback information in TB or CBG units regarding CBG-based uplink signals, and may determine the terminal’s contention window value based on at least one of the feedback information included in the DFI and the feedback information included in the UL authorized DCI.

[0035] CBG-based uplink signals may include uplink signals scheduled by the base station.

[0036] According to another embodiment of this disclosure, an operation method for a terminal in a wireless communication system for performing data transmission and reception includes: receiving from a base station first configuration information for uplink transmission based on code block groups (CBGs) and second configuration information including a downlink feedback information (DFI) bitmap configuration method; transmitting a CBG-based uplink signal to the base station based on the first configuration information; receiving from the base station, based on the second configuration information, a DFI including feedback information regarding the CBG-based uplink signal; and determining a contention window value for the terminal based on the feedback information included in the received DFI, wherein the DFI bitmap configuration method indicates whether the feedback is in units of transport blocks (TBs) or feedback for one or more CBGs.

[0037] In the following description, embodiments of the present disclosure will be illustrated with reference to the accompanying drawings. While embodiments are described, technical content known in the art and not directly related to the present disclosure will not be provided. This is to clearly convey the essential points of the disclosure by omitting unnecessary explanations.

[0038] For the same reason, some elements are exaggerated, omitted, or shown schematically in the accompanying drawings. Furthermore, the size of each element does not perfectly reflect its true size. In the drawings, the same elements are represented by the same reference numerals.

[0039] The advantages and features of this disclosure, as well as methods of implementing them, will become apparent from the embodiments described in detail below with reference to the accompanying drawings. In this regard, embodiments of this disclosure may take different forms and should not be construed as limited to the description set forth herein. Rather, these embodiments are provided to make this disclosure thorough and complete, and to fully convey the concept of this disclosure to those skilled in the art, and this disclosure is defined only by the appended claims. Throughout the specification, the same reference numerals denote the same elements.

[0040] It will be understood that the boxes or combinations of flowcharts in a flowchart can be executed by computer program instructions. Because these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, the instructions, executed by the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart boxes(s). Because these computer program instructions can also be stored in a computer-executable or computer-readable storage medium, which can instruct the computer or other programmable data processing apparatus to operate in a particular manner, the instructions stored in the computer-executable or computer-readable storage medium can create an article of manufacture including instruction means for implementing the functions specified in the flowchart boxes(s). Because the computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, a series of operational steps can be performed on the computer or other programmable apparatus to produce a computer-implemented process; therefore, the instructions that execute on the computer or other programmable apparatus can provide steps for implementing the functions specified in the flowchart boxes(s).

[0041] Furthermore, each box in the flowchart can represent a module, code segment, or code section, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the boxes may not occur in the order shown. For example, two boxes shown consecutively may actually execute substantially simultaneously, or these boxes may sometimes execute in reverse order, depending on the functions involved.

[0042] As used herein, the term "unit" refers to a software element or hardware element, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC), that performs a specific function. However, the term "unit" is not intended to be limited to software or hardware. A "unit" can be configured to reside in an addressable storage medium or to operate one or more processors. Thus, for example, the term "unit" can refer to components such as software components, object-oriented software components, class components, and task components, and can include processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, or variables. The functionality 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 to operate one or more central processing units (CPUs) in a device or secure multimedia card. Additionally, according to embodiments, a "unit" can include one or more processors. In fifth-generation (5G) systems, support for a variety of services is considered compared to existing fourth-generation (4G) systems. Examples of representative services may include enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), massive machine-type communications (mMTC), and evolved multimedia broadcast / multicast services (eMBMS). A system providing URLLC services may be referred to as an URLLC system, and a system providing eMBB services may be referred to as an eMBB system. Furthermore, the terms "service" and "system" are used interchangeably.

[0043] As mentioned above, a variety of services can be provided to users in a communication system, and in order to provide a variety of services to users, an apparatus and method are needed to provide services in the same time domain according to the characteristics of the services.

[0044] In wireless communication systems (e.g., LTE or LTE-A advanced systems or 5G New Radio (NR) systems), base stations can transmit downlink control information (DCI) including resource allocation information to terminals via a downlink control channel (Physical Downlink Control Channel (PDCCH)). Through this DCI, downlink signals are transmitted from the base station to the terminal, thereby configuring the terminal to receive at least one of the following downlink signals: downlink control information (e.g., Channel State Information Reference Signal (CSI-RS)), a broadcast channel (Physical Broadcast Channel (PBCH)), and a downlink data channel (Physical Downlink Shared Channel (PDSCH)). For example, a base station transmits a DCI to a terminal via PDCCH indicating that it will receive PDSCH in subframe n, and the terminal receiving the DCI receives PDSCH in subframe n according to the received DCI. In LTE, LTE-A, and 5G New Radio (NR) systems, the base station can transmit downlink control information (DCI) including resource allocation information to terminals via a downlink control channel (Physical Downlink Control Channel (PDCCH)). In A or NR systems, a base station can send a downlink control channel (PDCCH) containing uplink resource allocation information (DCI) to a terminal, thereby configuring the terminal to send at least one uplink signal from the uplink control channel (e.g., sounding reference signal (SRS), uplink control information (UCI), or physical random access channel (PRACH)) and the uplink data channel (physical uplink shared channel (PUSCH)). For example, a terminal that receives uplink transmission configuration information (or uplink DCI or UL grant) sent from the base station via the PDCCH in subframe n can perform uplink data channel transmission (hereinafter referred to as PUSCH transmission) according to a pre-configured time (e.g., n+4), a time configured via higher-layer signaling (e.g., n+k), or uplink signal transmission time indicator information included in the uplink transmission configuration information (e.g., n+k).

[0045] When performing a configured downlink transmission from a base station to a terminal via an unlicensed frequency band, or a configured uplink transmission from a base station to a terminal via an unlicensed frequency band, the transmission device (base station or terminal) may perform a channel access procedure (or Listen-Before-Tell (LBT)) for the unlicensed frequency band. This involves configuring signal transmission before or immediately after the configured signal transmission start time, and if the unlicensed frequency band is determined to be idle based on the result of the channel access procedure, the device may access the unlicensed frequency band and perform the configured signal transmission. If the unlicensed frequency band is determined to be not idle or is occupied based on the channel access procedure performed by the transmission device, the transmission device may be unable to access the unlicensed frequency band and therefore may not perform the configured signal transmission. In the channel access process within an unlicensed frequency band configured for signal transmission, the transmitting device receives signals from the unlicensed frequency band for a specific period or a period calculated according to predefined rules (e.g., a period calculated using at least one random value selected by the base station or terminal). The strength of the received signal is compared to a predefined threshold or a threshold calculated by a function to determine whether the unlicensed frequency band is idle. The function includes at least one parameter among channel bandwidth, the signal bandwidth of the signal to be transmitted, the strength of the transmission power, and the signal beamwidth of the signal to be transmitted. For example, if the signal strength received by the transmitting device during a 25µs period is less than the predefined threshold of -72dBm, it can be determined that the unlicensed frequency band is idle, and the configured signal transmission can be performed. In this case, the maximum time for signal transmission can be limited based on the maximum channel occupancy time defined for each country or region in the unlicensed frequency band, or the type of transmitting device (e.g., base station, terminal, master device, or slave device). For example, in Japan, after performing a channel access process in a 5GHz unlicensed frequency band, a base station or terminal can occupy the channel for a maximum of 4ms without an additional channel access process and can transmit signals. When the received signal strength during a 25µs period is greater than the predefined threshold of -72dBm, the base station determines that the unlicensed frequency band is not idle and does not transmit signals.

[0046] In 5G communication systems, various techniques have been introduced to perform retransmissions in blocks and send uplink signals without uplink scheduling information in order to provide a variety of services and support high data rates. Therefore, when performing 5G communication over unlicensed frequency bands, a more efficient channel access process considering various parameters is necessary.

[0047] Wireless communication systems have evolved from providing voice-centric services in their early stages to providing broadband wireless communication systems offering high-speed, high-quality packet data services, such as 3GPP's High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE or Evolved Universal Terrestrial Radio Access (E-UTRA)), LTE-Advanced (LTE-A) and LTE-Pro, 3GPP2's High-Speed ​​Packet Data (HRPD) and Ultra Mobile Broadband (UMB), and IEEE 802.16e standards. Furthermore, 5G wireless communication systems are under development, with 5G or new radio (NR) communication standards being developed.

[0048] In wireless communication systems including 5G, at least one of the following services can be provided to terminals: enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC). Services can be provided to the same terminal within the same time interval. In embodiments, eMBB service can be used for high-speed transmission of high-capacity data, mMTC service can be used to minimize terminal power consumption and access from multiple terminals, and URLLC service can be used for high reliability and low latency; however, this disclosure is not limited thereto. These three services are likely to be the main scenarios in LTE systems or subsequent 5G / NR systems.

[0049] When a base station schedules data corresponding to eMBB service in any terminal within a specific transmission time interval (TTI) and is required to transmit URLLC data within the TTI, the base station does not transmit some eMBB data in the frequency band where eMBB data has already been scheduled and is being transmitted, but instead transmits the generated URLLC data in that frequency band. The terminal scheduled with eMBB data and the terminal scheduled with URLLC data can be the same terminal or different terminals. In this case, some eMBB data that has already been scheduled and is being transmitted is not transmitted, thus increasing the risk of eMBB data corruption. Therefore, in this situation, it is necessary to determine the method for processing signals received by the terminal that schedules eMBB data or the terminal that schedules URLLC data, as well as the method for receiving signals.

[0050] The terms used below are defined with reference to the functions described in this disclosure and may have different meanings depending on the intent, habits, etc. of the user or operator. Therefore, the terms used herein must be defined based on their meaning and the description throughout the specification. In the following, a base station (BS) is an entity that allocates resources to a terminal and may be at least one of an eNode B (eNB), a Node B (NB), a radio access unit, a BS controller, or a node on a network. Examples of terminals may include user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, multimedia system capable of performing communication functions, etc. In this disclosure, downlink (DL) refers to the radio transmission path of signals sent from the base station to the terminal, and uplink (UL) refers to the radio transmission path of signals sent from the terminal to the base station. Furthermore, in the following, one or more embodiments of this disclosure will be described as examples of LTE or LTE-A systems, but these one or more embodiments may also be applied to other communication systems with similar technical backgrounds or channel configurations. For example, other communication systems may include 5G mobile communication technologies (5G, New Radio, or NR) developed after LTE-A. Furthermore, the embodiments of this disclosure can be adapted to other communication systems with modifications determined by those skilled in the art themselves, without significantly departing from the scope of this disclosure.

[0051] As a representative example of a broadband wireless communication system, the NR system employs Orthogonal Frequency Division Multiplexing (OFDM) for the downlink (DL) and both OFDM and Single-Carrier Frequency Division Multiple Access (SC-FDMA) for the uplink (UL). The uplink is the wireless link through which a terminal (or User Equipment (UE)) or mobile station (MS) transmits data or control signals to a base station (or eNode B), while the downlink is the wireless link through which the base station transmits data or control signals to the terminal. In this multiple access scheme, data or control information for each user is classified by typically allocating and manipulating it, ensuring that the time-frequency resources used to transmit data or control information for each user do not overlap, i.e., orthogonality is established.

[0052] The NR system employs a Hybrid Automatic Repeat Request (HARQ) scheme. When decoding fails during the initial transmission, this scheme retransmits the corresponding data at the physical layer. In the HARQ scheme, when the receiver fails to decode the data accurately, it sends a negative acknowledgment (NACK) to the transmitter, indicating decoding failure, so that the transmitter retransmits the corresponding data at the physical layer. The receiver improves data reception performance by combining the retransmitted data with the data that failed to decode. Furthermore, when the receiver successfully decodes the data, it sends an acknowledgment (ACK) to the transmitter, indicating successful decoding, causing the transmitter to send new data.

[0053] Figure 1 This is a diagram illustrating the structure of uplink / downlink time-frequency domain transmission in an NR system.

[0054] refer to Figure 1 The horizontal axis represents the time domain, and the vertical axis represents the frequency domain. In the time domain, the smallest unit of transmission is an OFDM or DFT-s-OFDM symbol, and N symb Each OFDM or DFT-s-OFDM symbol 101 is configured in a time slot 102. Here, an OFDM symbol refers to a symbol used for transmitting or receiving signals using an OFDM scheme, and a DFT-s-OFDM symbol refers to a symbol used for transmitting or receiving signals using a DFT-s-OFDM or SC-FDMA scheme. In the following description, for ease of explanation, this disclosure will be based on OFDM symbols without distinguishing between OFDM symbols and DFT-s-OFDM symbols, and will be described based on downlink signal transmission / reception, but may also be applied to uplink signal transmission / reception.

[0055] When the subcarrier spacing is 15 kHz, one time slot constitutes one subframe 103, and the length of each time slot and subframe can be 1 ms. Here, the number of time slots and the length of the time slots constituting one subframe 103 can vary depending on the subcarrier spacing. For example, when the subcarrier spacing is 30 kHz, two time slots can constitute one subframe 103. In this case, the length of the time slot is 0.5 ms, and the length of the subframe is 1 ms. Furthermore, radio frame 104 is a time-domain interval consisting of 10 subframes. The smallest transmission unit in the frequency domain is a subcarrier, and the entire system transmission bandwidth includes a total of N. sc BW There are 105 subcarriers. However, this specific value can be applied differently. For example, in an LTE system, the subcarrier spacing is 15 kHz, but two time slots form a subframe 103, where the time slot length is 0.5 ms and the subframe length is 1 ms.

[0056] In the time-frequency domain, the basic unit of a resource can be a resource element (RE) 106, and the RE 106 can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB or physical resource block (PRB)) 107 can be represented by N in the time domain. symb A consecutive OFDM symbol 101 and N in the frequency domain SC RB It is defined by a series of consecutive subcarriers 108. Therefore, one RB 107 in a time slot can include N symb ×N SC RB One RE. Typically, the smallest data allocation unit in the frequency domain is RB 10⁷. In NR systems, typically N... symb=14 and N SC RB =12, and the number of RBs is N RB It can vary depending on the bandwidth of the system's transmission frequency band. In LTE systems, typically, N symb =7 and N SC RB =12, and N RB It can vary depending on the bandwidth of the system's transmission frequency band.

[0057] Downlink control information can be transmitted within the first N OFDM symbols of a subframe. Generally, N = {1, 2, 3}, and the terminal can be configured via higher-layer signaling to transmit the number of symbols from the base station. The base station can change the number of symbols that can be transmitted in each time slot based on the amount of control information to be transmitted in the current time slot, and can send information about the number of symbols to the terminal via a separate downlink control channel.

[0058] In NR or LTE systems, downlink data or uplink data scheduling information can be transmitted from the base station to the terminal via downlink control information (DCI). DCIs are defined according to various formats, and each format can indicate whether the scheduling information is uplink data scheduling information (UL license) or downlink data scheduling information (DL license), whether the DCI is a compact DCI with small-size control information, whether the DCI is a spare DCI, whether spatial multiplexing using multiple antennas is applied, or whether the DCI is used for power control. For example, a DCI format for uplink data scheduling control information (UL license) (e.g., NR DCI format 0_1) may include at least one of the following control information.

[0059] -Carrier indicator-0 or 3 bits

[0060] -UL / SUL indicator-0 or 1 bit

[0061] - Downlink Feedback Information (DFI) flag - 0 or 1 bit

[0062] ● 1 bit, used when the terminal monitors DCI format 0_1 ​​with CRC scrambled with CS-RNTI and performs channel access in the shared spectrum. When the bit value is 0, it indicates activation of type 2 CG transmission, and when the bit value is 1, it indicates CG-DFI. When the terminal receives DCI format 0_1 ​​with CRC scrambled with C-RNTI / SP-CSI-RNTI / MCS-C-RNTI, it can reserve the corresponding bit.

[0063] ●Otherwise, it is 0 bits;

[0064] -DCI format identifier-[1] bits

[0065] -Bandwidth section indicator -0, 1, or 2 bits

[0066] Frequency domain resource allocation

[0067] ●For resource allocation type 0, Bit

[0068] ●For resource allocation type 1 Bit

[0069] -Time-domain resource allocation-1, 2, 3, or 4 bits

[0070] - Virtual resource block to physical resource block (VRB to PRB) mapping - 0 or 1 bit, only used for resource allocation type 1.

[0071] ● If only resource allocation type 0 is configured, then it is 0 bits;

[0072] ●Otherwise, it is 1 bit.

[0073] - Frequency hopping flag - 0 or 1 bit, used only for resource allocation type 1.

[0074] ● If only resource allocation type 0 is configured, then it is 0 bits;

[0075] ●Otherwise, it is 1 bit.

[0076] -Modulation and coding scheme-5 bits

[0077] -New Data Indicator- 1 bit

[0078] -Redundant version-2 bits

[0079] -HARQ process ID- 4 bits

[0080] -First downlink allocation index-1 or 2 bits

[0081] ● For a semi-static HARQ-ACK codebook, 1 bit;

[0082] ● For a dynamic HARQ-ACK codebook with a single HARQ-ACK codebook, 2 bits.

[0083] -Second downlink allocation index-0 or 2 bits

[0084] ● For a dynamic HARQ-ACK codebook with two HARQ-ACK subcodebooks, 2 bits;

[0085] ●Otherwise, it is 0 bits.

[0086] - TPC command for PUSCH scheduling - 2 bits

[0087] -SRS resource indicator- or Bit

[0088] ●For non-codebook-based PUSCH transmissions, Bit;

[0089] ●For codebook-based PUSCH transmission, Bit.

[0090] -Precoding information and number of layers-Up to 6 bits

[0091] - Antenna port - Maximum 5 bits

[0092] -SRS Request- 2 bits

[0093] - Channel State Information (CSI) Request - 0, 1, 2, 3, 4, 5, or 6 bits

[0094] - Code Block Group (CBG) transmission information - 0, 2, 4, 6, or 8 bits

[0095] - Phase Tracking Reference Signal (PTRS) - Demodulation Reference Signal (DMRS) Association - 0 or 2 bits

[0096] -beta_offset indicator -0 or 2 bits

[0097] -DMRS sequence initialization -0 or 1 bit

[0098] Following the channel coding and modulation process, DCI can be transmitted on either the Physical Downlink Control Channel (PDCCH) (hereinafter, it can be used interchangeably with control information) or the Enhanced PDCCH (EPDCCH) (hereinafter, it can be used interchangeably with enhanced control information). When the DFI field in the DCI field indicates 1, that is, when DCI format 0_1 ​​is used to configure Granted Downlink Feedback Information (CG-DFI), the fields of DCI format 0_1 ​​can include the following control information.

[0099] The HARQ-ACK bitmap is 16 bits long, where the bitmap is mapped to the HARQ process index in ascending order from the MSB to the LSB of the bitmap. For each bit of the bitmap, a value of 1 indicates ACK, and a value of 0 indicates NACK.

[0100] - TPC commands for scheduling PUSCH

[0101] - All remaining bits in format 0_1 ​​are set to zero.

[0102] Typically, DCI scrambles the PDCCH with a unique Radio Network Temporary Identifier (RNTI) (or Terminal Identifier C-RNTI) independent of each terminal, adds Cyclic Redundancy Check (CRC), performs channel coding, and then configures it for each individual PDCCH before transmission. In the time domain, PDCCHs are mapped and transmitted within the control channel transmission interval. The mapping location of PDCCHs in the frequency domain can be determined by the identifier (ID) of each terminal and can be distributed and transmitted across the entire system transmission band.

[0103] Downlink data can be transmitted via the Physical Downlink Shared Channel (PDSCH), which is a physical channel used for downlink data transmission. The PDSCH can be transmitted after the control channel transmission interval, and the detailed mapping position in the frequency domain and scheduling information such as modulation schemes are determined based on the DCI transmitted via the PDSCH.

[0104] The base station can inform the terminal, in the control information configuring the DCI, of the modulation scheme to be applied to the PDSCH to be transmitted and the size of the data to be transmitted via the modulation and coding scheme (MCS) (transmission block size (TBS)). According to an embodiment, the MCS can consist of 5 bits, or it can consist of bits less than or greater than 5 bits. The TBS corresponds to the size before the channel coding for error correction is applied to the data (transmission block (TB)) to be transmitted by the base station.

[0105] In this disclosure, the TB may include a Media Access Control (MAC) header, a MAC Control Element (CE), one or more MAC Service Data Units (SDUs), and padding bits. Alternatively, as another example, the TB may indicate a data unit or MAC Protocol Data Unit (PDU) from the MAC layer to the physical layer.

[0106] The NR system supports modulation schemes including Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64QAM, and 256QAM, with modulation orders (Qm) of 2, 4, and 6, respectively. That is, 2 bits per symbol for QPSK modulation, 4 bits per symbol for 16QAM modulation, 6 bits per symbol for 64QAM modulation, and 8 bits per symbol for 256QAM modulation. Furthermore, modulation schemes higher than 256QAM can be used depending on system variations.

[0107] In NR systems, uplink / downlink HARQ employs an asynchronous HARQ scheme, where data retransmission times are not fixed. For example, in the downlink case, when the base station receives a HARQ NACK from the terminal as feedback on the initial data sent by the base station, the base station can arbitrarily determine the transmission time of the data to be retransmitted based on scheduling operations. As a result of decoding the received data in response to the HARQ operation, the terminal can buffer data identified as erroneous and then combine the buffered data with the data retransmitted from the base station. HARQ ACK / NACK information for the PDSCH transmitted in subframe nk can be sent from the terminal to the base station via PUCCH or PUSCH in subframe n. In 5G communication systems such as NR systems, the value of k can be transmitted simultaneously with the received DCI included in the indication or scheduling subframe nk, or it can be configured in the terminal via higher-layer signaling. In this case, the base station can configure one or more values ​​of k via higher-layer signaling, or it can indicate a specific value of k via DCI. Here, k can be determined based on the terminal's HARQ-ACK processing capability; in other words, the minimum time required to receive the PDSCH and generate and report the HARQ-ACK for the PDSCH. Furthermore, the terminal can use a default value or a predefined value before configuring the value of k.

[0108] In NR systems, a CRC can be added to the end or beginning of a TB (Transmission Block) to be transmitted from the uplink or downlink. The CRC can have 16 bits, 24 bits, or a predetermined number of bits, or it can have bits that vary depending on channel conditions, and it can be used to determine whether channel coding was successful. The block with the TB and CRC added can be divided into multiple code blocks (CBs). The maximum size of the CB can be predetermined, and in this case, the last CB can be smaller than the other CBs, or 0, random values, or 1 can be inserted into the last CB to make the last CB the same length as the other CBs. A CRC can be added to each CB, where the CRC can have 16 bits, 24 bits, or a predetermined number of bits, and it can be used to determine whether channel decoding was successful. Here, in NR systems, to improve retransmission efficiency, success or failure can be determined when decoding each CB, rather than on a TB-by-TB basis. The result of decoding each CB is grouped into CBGs and sent as ACK or NACK. The maximum size of the CBG is determined by a value configured at a higher layer and applies equally to all HARQ process numbers.

[0109] Although NR systems have been described to illustrate wireless communication systems, methods, and apparatus according to embodiments of this disclosure, this disclosure is not limited to NR systems and can be applied to various wireless communication systems such as LTE, LTE-A, LTE-A-Pro, and 5G. Furthermore, although this disclosure has been described based on systems and devices that transmit / receive signals using unlicensed frequency bands, this disclosure can also be applied to systems operating in licensed frequency bands.

[0110] In this disclosure, higher-layer signaling or higher-layer signaling refers to a method of transmitting signals from a base station to a terminal using a downlink data channel of the physical layer, or from a terminal to a base station using an uplink data channel of the physical layer, and includes methods of transmitting signals via Radio Resource Control (RRC) signaling, Packet Data Convergence Protocol (PDCP) signaling, or Media Access Control (MAC) control element (CE). Higher-layer signaling or higher-layer signaling may include system information, such as a System Information Block (SIB), which is publicly transmitted to multiple terminals.

[0111] In a system that performs communication in an unlicensed frequency band, a transmitting device (base station or terminal) that wants to send signals through the unlicensed frequency band can perform a channel access procedure (or listen-before-tell (LBT)) on the unlicensed frequency band before sending signals. If the channel access procedure determines that the unlicensed frequency band is idle, the transmitting device can access the unlicensed frequency band and send signals. If the channel access procedure determines that the unlicensed frequency band is not idle, the transmitting device cannot send signals.

[0112] During channel access in an unlicensed frequency band, the transmission device typically measures the strength of the signal received through the unlicensed frequency band for a fixed time or a time calculated according to predefined rules (e.g., a time calculated based on a random value selected at least by the base station or terminal), and compares the measured strength of the received signal with a predefined threshold or a threshold calculated by a function to determine the idle state of the unlicensed frequency band. This function is used to determine the strength of the received signal based on at least one of the following parameters: channel bandwidth, signal bandwidth of the signal to be transmitted, and transmission power strength.

[0113] For example, a transmission device can measure the strength of the received signal during a period of X μs (e.g., 25 μs) immediately before the signal is to be transmitted, and when the measured signal strength is less than a predefined or calculated threshold T (e.g., -72 dBm), the transmission device can determine that the unlicensed frequency band is idle and can transmit the configured signal. The maximum duration for 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 frequency band, or the type of transmission device (e.g., base station, terminal, master device, or slave device). For example, in Japan, after performing a channel access procedure in an unlicensed frequency band of 5 GHz, a base station or terminal can occupy the channel for a maximum of 4 ms in an unlicensed frequency band determined to be idle and transmit a signal without an additional channel access procedure.

[0114] More specifically, when a base station or terminal attempts to transmit downlink or uplink signals in an unlicensed frequency band, the channel access procedures that can be performed by the base station or terminal can be classified into at least the following types.

[0115] Type 1: Uplink / downlink signal transmission is performed after the channel access procedure is executed during a variable time period.

[0116] Type 2: Uplink / downlink signal transmission is performed after the channel access procedure is executed within a fixed time period.

[0117] Type 3: Performing uplink or downlink signal transmission without performing a channel access procedure.

[0118] In the following description, although the present disclosure interchangeably describes the case of a base station transmitting downlink signals to a terminal via an unlicensed frequency band and the case of a terminal transmitting uplink signals to a base station via an unlicensed frequency band, the description of the present disclosure is equally applicable to the case of a terminal transmitting uplink signals to a base station via an unlicensed frequency band and a base station transmitting downlink signals to a terminal via an unlicensed frequency band, or some modifications thereof may be applied. Therefore, a detailed description of downlink signal transmission / reception is omitted. Furthermore, the present disclosure assumes that one data message (codeword or TB) or uplink data message is transmitted / received between the base station and the terminal. However, the description of the present disclosure can also be applied to the case of a base station transmitting downlink signals to multiple terminals, or the case of transmitting / receiving multiple codewords or TBs between the base station and the terminal.

[0119] A transmission node (hereinafter referred to as a base station or terminal) attempting to transmit signals through an unlicensed frequency band can determine its channel access procedure based on the type of signal to be transmitted. For example, when a base station attempts to transmit a downlink signal that includes a downlink data channel in an unlicensed frequency band, it can perform a type 1 channel access procedure. Furthermore, when a base station attempts to transmit a downlink signal that does not include a downlink data channel (e.g., a synchronization signal or downlink control channel) in an unlicensed frequency band, it can perform a type 2 channel access procedure and transmit the downlink signal.

[0120] The channel access procedure scheme can be determined based on the transmission length of the signal to be transmitted in the unlicensed frequency band, or the length of the time or interval during which the unlicensed frequency band is occupied and used. Generally, performing a Type 1 channel access procedure takes longer than performing a Type 2 channel access procedure. Therefore, a Type 2 channel access procedure can be performed when transmitting signals during a short time interval or a period equal to or shorter than a reference time (e.g., X ms or Y symbols). Conversely, a Type 1 channel access procedure can be performed when transmitting signals during a long time interval or a period longer than or equal to the reference time (e.g., X ms or Y symbols). In other words, different types of channel access procedures can be performed based on the duration of unlicensed frequency band usage.

[0121] When performing a Type 1 channel access procedure according to at least one of the above criteria, the channel access priority level can be determined based on the Quality of Service Level Identifier (QCI) of the signal to be transmitted in the unlicensed band, and the channel access procedure can be performed using at least one of the predefined configuration values ​​shown in Table 1 for the determined channel access priority level. For example, QCI1, 2, and 4 are the QCI values ​​for services such as voice conversations, video conversations (live streams), and non-video conversations (buffered streams), respectively. When a signal for a service that does not match the QCI in Table 1 is to be transmitted in the unlicensed band, the QCI closest to that service and the QCI in Table 1 can be selected, and its channel access priority level can be selected.

[0122] Table 1 shows the mapping relationship between channel access priority level and QCI.

[0123] [Table 1]

[0124] Channel access priority QCI 1 1，3，5，65，66，69，70 2 2，7 3 4，6，8，9 4 -

[0125] For example, the set of delay durations, contention window values ​​or sizes (CW_p), minimum and maximum contention window values ​​(CW_min, p and CW_max, p), and maximum channel occupancy interval (T_mcot, p) based on the determined channel access priority level p can be determined using Table 2. In other words, a base station attempting to transmit downlink signals through an unlicensed frequency band performs a channel access procedure for the unlicensed frequency band for at least the duration T_f + m_p * T_sl. When performing a channel access procedure at channel access priority level 3 (p = 3), the required delay duration T_f + m_p * T_sl can be configured using m_p = 3. When it is determined that the unlicensed frequency band is idle during the m_p * T_sl time period, N = N - 1. In this case, N is chosen as a random integer value between 0 and the contention window (CW_p) value when performing the channel access procedure. In the case of channel access priority level 3, the minimum contention window and the maximum contention window are 15 and 63, respectively. When it is determined that the unlicensed frequency band is idle during the delay duration and the additional channel access procedure interval, the base station may transmit signals through the unlicensed frequency band for a time period of T_mcot,p (8ms). Table 2 shows the channel access priority levels in the downlink. Although this disclosure is described using downlink channel access priority levels for ease of interpretation, the channel access priority levels in Table 2 may be reused, or channel access priority levels for uplink transmissions may be defined and used in the uplink.

[0126] [Table 2]

[0127]

[0128] The initial value of the contention window (CW_p) is the minimum value of the contention window (CW_min,p). A base station selecting value N performs a channel access procedure during the T_sl interval. When the unlicensed frequency band is determined to be idle through the channel access procedure performed during T_sl, the base station can change N to N-1 (N = N-1). When N = 0, the base station can transmit signals through the unlicensed frequency band for a maximum of T_mcot,p. When the unlicensed frequency band determined through the channel access procedure during T_sl is not idle, the base station can perform the channel access procedure again without changing the value of N.

[0129] The contention window value (CW_p) can be changed based on the time point at which the base station (or terminal) initiates the channel access procedure, the time point at which the base station (or terminal) selects the N value to perform the channel access procedure, or the result of receiving downlink (or uplink) data in a reference subframe, reference duration, or reference time slot within the most recent downlink (or uplink) signal transmission interval (or MCOT) transmitted by the base station (or terminal) through an unlicensed frequency band. In other words, the base station (or terminal) receives reports about the results of receiving downlink (or uplink) data from the reference subframe, reference duration, or reference time slot, and increases or decreases the size of CW_p based on the proportion (Z) of NACKs or the number (or proportion) of ACKs in the received reports about the reception results.

[0130] The initial value of the contention window (CW_p) is the minimum value of the contention window (CW_min,p). The base station selecting the value of N performs a channel access procedure during the T_sl interval. If the unlicensed frequency band is determined to be idle due to the channel access procedure performed during T_sl, the base station can change N to N-1 (N = N-1). When N = 0, the base station can transmit signals through the unlicensed frequency band for a maximum of T_mcot,p. If the unlicensed frequency band determined by the channel access procedure during T_sl is not idle, the base station can perform the channel access procedure again without changing the value of N.

[0131] The contention window value (CW_p) can change based on the time point from when the base station (or terminal) initiates the channel access procedure, the time point from when the base station (or terminal) selects the N value to perform the channel access procedure, or the result of the base station (or terminal) receiving downlink (or uplink) data from the reference subframe, reference duration, or reference time slot in the most recent downlink (or uplink) signal transmission interval (or MCOT) transmitted by the unlicensed frequency band. In other words, the base station (or terminal) receives reports about the results of the terminal receiving downlink (or uplink) data from the reference subframe, reference duration, or reference time slot, and increases or decreases the size of CW_p based on the proportion (Z) of NACKs or the number (or proportion) of ACKs in the received reports about the reception results.

[0132] Figure 2 It is a diagram used to describe the channel access process in unlicensed frequency bands.

[0133] refer to Figure 2The first transmission interval 240 of the downlink signal transmission interval 230 is a reference time slot for changing the contention window of the channel access procedure. In this downlink signal transmission interval 230, the base station transmits signals via the unlicensed frequency band most recently at the time point 270 when the base station begins the channel access procedure, or at the time point when the base station selects a value N to perform the channel access procedure, or immediately before that time point. When the base station cannot receive a report on the reception result of the downlink data channel transmitted in the first time slot 240 of the transmission interval 230, for example, when the time interval between the first time slot and the time point 270 when the base station begins the channel access procedure is equal to or less than n time slots or subframes, that is, when the base station begins the channel access procedure before the time when the terminal can report the reception result of the downlink data channel in the first time slot 240, the first subframe of the most recent downlink signal transmission interval before the downlink signal transmission interval 230 is the reference subframe. In other words, if the base station cannot receive the reception result of downlink data transmitted in reference time slot 240 from the terminal at time point 270 when the base station begins the channel access procedure, or at the time point when the base station selects a value of N to perform the channel access procedure, or immediately before that time point, the base station can determine the first time slot of the most recently transmitted downlink signal transmission interval from the previously received downlink data channel reception results from the terminal as the reference time slot. The base station can determine the size of the contention window to be used in the channel access procedure by using the reception result of downlink data received from the terminal, which is transmitted through the downlink data channel in the reference time slot.

[0134] For example, when it is determined that in downlink signals transmitted via unlicensed frequency bands, at least 80% of the received results of downlink data sent to the terminal via the downlink data channel in the first time slot are NACK (or when all received results are NACK), a base station that has transmitted downlink signals through the channel access procedure (CW_p=15) configured with channel access class 3 (p=3) can increase the contention window value from the initial value (CW_p=15) to the next contention window value (CW_p=31). When the base station has already transmitted CBG-based downlink signals, when it is determined that in downlink signals transmitted via unlicensed frequency bands, at least 90% of the received results of CBG sent to the terminal via the downlink data channel in the first time slot are NACK, the contention window can be increased from the initial value (CW_p=15) to the next contention window value (CW_p=31).

[0135] When at least 80% of the terminal's received results are not determined to be NACK, or when at least TB of received results in the reference time slot is determined to be ACK by another method, the base station may maintain the contention window value at its current value or change it to the initial value of the contention window. When at least 10% of the CBG of the terminal's received results are determined to be ACK during the base station's CBG-based transmission, the base station may change the contention window value to the initial value. In this case, the change of the contention window may be applied publicly to all channel access priority levels, or it may be applied only to the channel access priority level used for the channel access procedure. Here, the method for determining the validity of the received results for determining the change in the size of the contention window is described below; in other words, the method for determining the value of Z from the received results of downlink data transmitted or reported by the terminal to the base station relative to downlink data transmitted through the downlink data channel in the reference subframe or reference time slot for determining the change in the size of the contention window.

[0136] When a base station transmits one or more codewords or TBs to one or more terminals in a reference subframe or reference time slot, the base station can determine the value of Z based on the proportion of NACKs in the reception results sent or reported by the terminal for the TBs received in the reference subframe or reference time slot. For example, when two codewords or two TBs are transmitted to a terminal in a reference subframe or reference time slot, the base station receives or is reported the reception results of the downlink data signals for these two TBs from the terminal. When the proportion of NACKs Z in the two reception results is equal to or greater than a predefined or configured threshold between the base station and the terminal (e.g., Z = 80%), the base station can change or increase the size of the contention window.

[0137] In this scenario, when a terminal bundles the reception results of downlink data including one or more subframes (e.g., M subframes) of reference subframes or time slots and sends or reports them to the base station, the base station can determine that the terminal has sent M reception results. The base station can determine the value of Z based on the proportion of NACKs among the M reception results and change, maintain, or initialize the size of the contention window.

[0138] When the reference subframe is the reception result of the second time slot in two time slots included in a subframe, the value of Z can be determined based on the proportion of NACKs in the reception results of downlink data received in the reference subframe (in other words, the second time slot) and the next subframe, which are sent or reported by the terminal to the base station.

[0139] Furthermore, when the scheduling information or downlink control information of the downlink data channel sent by the base station is sent in the same cell or frequency band as the cell or frequency band of the downlink data channel, or when the scheduling information or downlink control information of the downlink data channel sent by the base station is sent in an unlicensed frequency band but in a different cell or frequency band than the cell of the downlink data channel, when it is determined that the terminal did not send the reception result of the downlink data received in the reference subframe or reference time slot, and when the reception result of the downlink data sent by the terminal is determined to be discontinuous transmission (DTX), NACK / DTX or any state, the base station can determine the terminal's reception result as NACK and determine the value of Z.

[0140] Furthermore, when the downlink data channel scheduling information or downlink control information transmitted by the base station is transmitted through a licensed frequency band, if the reception result of the downlink data transmitted by the terminal is determined to be DTX, NACK / DTX, or any other state, the base station may not add the terminal's reception result to the reference value Z for the contention window change. In other words, the base station can determine the value of Z and ignore the terminal's reception result.

[0141] Furthermore, when the base station transmits scheduling information or downlink control information for the downlink data channel through the licensed frequency band, if the base station does not actually transmit downlink data (no transmission) in the downlink data reception results of the reference subframe or reference time slot sent or reported to the base station by the terminal, the base station can determine the value of Z and ignore the reception results for downlink data sent or reported by the terminal.

[0142] Considering various services and requirements, 5G systems need to flexibly define and operate frame structures. For example, different services can have different subcarrier spacings as needed. The multiple subcarrier spacings supported by a pre-5G communication system can be determined using Equation 1 below.

[0143] [Equation 1]

[0144] Δf=f02 m

[0145] Here, f0 represents the basic subcarrier spacing of the system, and m represents an integer scaling factor. For example, when f0 is 15 kHz, a set of subcarrier spacings for a 5G communication system can include 3.75 kHz, 7.5 kHz, 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, and 480 kHz. The available set of subcarrier spacings can vary depending on the frequency band. For example, 3.75 kHz, 7.5 kHz, 15 kHz, 30 kHz, and 60 kHz can be used for frequency bands equal to or less than 6 GHz, and 60 kHz, 120 kHz, and 240 kHz can be used for frequency bands equal to or greater than 6 GHz.

[0146] The length of an OFDM symbol can vary depending on the subcarrier spacing that makes up the OFDM symbol. This is because, according to the characteristics of OFDM symbols, there is a reciprocal relationship between the subcarrier spacing and the length of the OFDM symbol. For example, when the subcarrier spacing is doubled, the symbol length is shortened by half, and when the subcarrier spacing is reduced by half, the symbol length is doubled.

[0147] Next, we will describe the resource areas of data transmission channels in a 5G communication system.

[0148] Figure 3 This is a diagram illustrating downlink or uplink scheduling methods and resource areas in an NR system.

[0149] The terminal monitors or searches for PDCCH 310 in a downlink control channel (hereinafter referred to as PDCCH) area (hereinafter referred to as control resource set (CORESET) or search space (SS)) configured via higher-layer signaling from the base station. The downlink control channel area may include information about time domain 314 and frequency domain 312, and the information about time domain 314 may be configured in units of symbols, and the information about frequency domain 312 may be configured in units of RBs or RB groups. When the terminal detects PDCCH 310 in time slot i 300, the terminal obtains downlink control information (DCI) transmitted via the detected PDCCH 310. Through the received DCI, the terminal can obtain scheduling information for downlink data channels or uplink data channels. In other words, the DCI may at least include information about the resource area (or PDSCH transmission area) through which the terminal should receive downlink data channels (hereinafter referred to as PDSCH) transmitted from the base station, or information about the resource area allocated by the base station to the terminal for uplink data channel (hereinafter referred to as PUSCH) transmission. The following describes the scenario where the terminal is scheduled to transmit uplink data channel (PUSCH). Upon receiving a DCI, the terminal can obtain the slot index or offset information K for receiving the PUSCH through the DCI and determine the PUSCH transmission slot index. For example, based on slot i 300 where PDCCH 310 is received, the terminal can determine, through the received offset information K, that it is scheduled to transmit PUSCH in slot i+K 305. The terminal can also determine the PUSCH start symbol or time in slot i+K 305 or slot i+K based on the CORESET where PDCCH 310 is received, through the received offset information K. Furthermore, the terminal can obtain information about the time-frequency resource area 340 in PUSCH transmission slot 305 based on the DCI. Here, the PUSCH transmission frequency resource area information 330 can be PRB or PRB group unit information. Meanwhile, the PUSCH transmission frequency resource area information 330 is an area included in the initial uplink bandwidth (initial BW) or initial uplink bandwidth portion (initial BWP) determined or configured by the terminal through the initial access procedure. When the terminal receives the uplink bandwidth (BW) or uplink bandwidth portion (BPW) through higher-layer signaling, the PUSCH transmission frequency resource area information 330 may be an area included in the uplink bandwidth (BW) or uplink bandwidth portion (BWP) configured through higher-layer signaling.

[0150] The PUSCH transmission time resource area information 325 can be symbol or symbol group unit information, or it can be information indicating absolute time information. Here, the PUSCH transmission time resource area information 325 can be represented as a combination of PUSCH transmission start time or symbol and PUSCH length or PUSCH end time or symbol, and can be included in the DCI as a field or value. In this case, the PUSCH transmission time resource area information 325 can be included in the DCI as a field or value indicating each of the PUSCH transmission start time or symbol and the PUSCH length or PUSCH end time or symbol. The terminal can transmit PUSCH within the PUSCH transmission resource area 340 determined by the DCI.

[0151] In 5G communication systems, uplink signals can be transmitted without uplink scheduling information to provide various services and support high data rates. Specifically, when transmitting uplink signals without uplink scheduling information, information regarding resource allocation, MCS, etc., for uplink transmission can be configured via RRC signaling or DCI of PDCCH. Furthermore, the uplink transmissions that can be executed can be categorized into at least one of the following types based on the uplink transmission configuration reception method.

[0152] - Type 1: Uplink transmission configuration using RRC signaling

[0153] Type 2: Uplink transmission configuration using the downlink control channel of the physical layer

[0154] Figure 4 This is a diagram illustrating downlink or uplink scheduling methods and resource areas in an NR system.

[0155] refer to Figure 4 This illustrates the case of transmitting uplink signals in an unlicensed frequency band without uplink scheduling information. In the unlicensed frequency band, a channel access procedure is performed to transmit uplink signals without uplink scheduling information. Here, when a terminal accesses the unlicensed frequency band by performing a channel access procedure during a variable time period, the terminal can schedule downlink transmission in the last time slot or last subframe 404 of the maximum channel occupancy time 412 via the channel occupancy time sharing indicator in the uplink control information 405. Here, the base station determines channel access by performing a channel access procedure during a fixed time period, and the terminal configures the last symbol of the time slot or subframe 408 used for uplink transmission as the gap for the base station's channel access procedure. Downlink transmission is limited to, as... Figure 4PDCCH 409 is shown, and the start symbol of PDCCH 409 is limited to the first symbol of the last time slot or the last subframe 404, and has a length of no more than two symbols.

[0156] Simultaneously, the base station can send the decoding results of the received uplink signals to the terminal using a bitmap of DCI format 0_1 ​​(CG-DFI). Here, the base station can send ACK / NACK information for all HARQ process numbers through the bitmap. Furthermore, the base station can indicate the ACK / NACK feedback for transmission corresponding to each HARQ process number in 1 bit. HARQ process numbers that have not yet been sent or are empty can be configured with a default value (NACK or ACK). Additionally, the terminal can change (or adjust) the aforementioned contention window value by using the ACK / NACK information included in the bitmap. In NR systems, when uplink signals from the transmitting terminal are configured through higher-level configuration, the base station can configure uplink signal transmission by dividing a TB (or PUSCH) into CBGs. In other words, the base station can receive one or more CBGs through one uplink signal (PUSCH or TB). Here, when sending feedback information about one or more CBGs transmitted through each HARQ process (or uplink signal) to the terminal in the CG-DFI bitmap, the base station can notify the reception result in 1 bit of information. Therefore, it is necessary to describe a method for configuring the bitmap of CG-DFI by converting each received result into 1 bit of information when the base station receives one or more CBGs.

[0157] In this disclosure, a method for the base station to configure the CG-DFI bitmap and a method for the terminal to identify and interpret the CG-DFI bitmap received from the base station will be described when the terminal performs a CBG-based uplink transmission to the base station to send HARQ-ACK feedback in the CG-DFI bitmap in an unlicensed frequency band.

[0158] The methods and apparatus described below in the embodiments of this disclosure are not limited to each embodiment and can be used to transmit bitmaps of HARQ-ACK feedback by using combinations of all or some embodiments of this disclosure. Embodiments of this disclosure will be described using the case of transmitting HARQ-ACK feedback for uplink signals as an example; however, this disclosure can also be applied to cases where a terminal transmits HARQ-ACK feedback for downlink signals. Furthermore, embodiments of this disclosure will be described based on base stations and terminals operating in unlicensed frequency bands. However, the methods and apparatus presented in the embodiments of this disclosure can also be applied to base stations and terminals operating not only in unlicensed frequency bands but also in licensed frequency bands or shared spectrum.

[0159] [Example 1]

[0160] In this embodiment, a method for a base station to indicate ACK / NACK transmission information for all HARQ processes using a bitmap and a method for a terminal to determine the received ACK / NACK information will be described for base stations and terminals operating in unlicensed frequency bands.

[0161] Regarding base stations and terminals transmitting / receiving signals in unlicensed frequency bands, it is assumed that the terminal is configured to perform PUCCH / PUSCH transmissions in one or more time slots via a configuration grant setting. Furthermore, the terminal can perform PUCCH / PUSCH transmissions in one or more time slots based on a configuration grant setting from the base station. When receiving the configuration grant transmission from the base station, the terminal can add a HARQ process number to the uplink control signal and transmit this uplink control signal simultaneously with the PUSCH transmission. Here, the HARQ process number used for configuration grant transmissions can be assigned by the base station and can also be used for license-based (scheduled) uplink transmissions. Simultaneously, the base station can configure the terminal with CBG-based uplink transmissions. When decoding CBG-based uplink signals, the base station can determine whether the transmission was successful or failed while performing decoding on each code block. Furthermore, the base station can be configured via L1 or higher layer signaling (e.g., SIB, MIC, MAC-CE, or RRC signaling) to operate a scheme for configuring a bitmap of CG-DFI based on a TB indicating HARQ-ACK feedback in 1 bit information for each HARQ process or based on a CBG indicating HARQ-ACK feedback for one or more CBGs for each HARQ process.

[0162] Figure 5 This is a diagram illustrating an embodiment of the present disclosure.

[0163] Reference Figure 5 The operation of this embodiment is described in detail. Figure 5 In this case, assume that the base station configures the size of the CBG to 2 through higher-layer signaling.

[0164] The base station can receive CBG-based uplink signals (PUSCH or TB) from the terminal. Furthermore, the base station can decode the received CBG-based uplink signals in units of CBG. When generating HARQ-ACK information bits (or HARQ process number) for the uplink signal, the base station can reconfigure (or change) the decoding result of the CBG. For example, when it is determined that at least one CBG is NACK as a result of decoding one or more CBGs configured to receive uplink signal 511 (TB or PUSCH) from the terminal, the base station can configure the CG-DFI bitmap by generating the HARQ-ACK information bits (or HARQ process number) of uplink signal 511 as NACK 515 (or 0 or 1). As another example, when it is determined that all CBGs are ACKs as a result of decoding one or more CBGs that configure the uplink signal 512 (TB or PUSCH) received from the terminal, the base station can configure the bitmap of CG-DFI by generating the HARQ-ACK information bits of the uplink signal (or HARQ process number) as NACK 516 (or 1 or 0).

[0165] Upon receiving a CG-DFI bitmap configured in this manner, the terminal can adjust the contention window value by using the bit information of the CG-DFI bitmap. The method by which the terminal determines the CG-DFI bitmap information to adjust the contention window value will be described below.

[0166] [Example 1-1] Competition window value adjustment based on TB unit information

[0167] When determining the bitmap information included in the received DFI, the terminal can determine that each bit of the bitmap represents ACK / NACK information based on TB. Specifically, the terminal can adjust (or change or configure) the contention window value based on one or more bits 515 and 516 of one or more uplink signals 511 and 512 (PUSCH or TB) transmitted in reference time slot (or duration) 500 from the bitmap information included in the received CG-DFI. For example, among the multiple feedback bits 515 and 516 of one or more uplink signals 511 and 512 (PUSCH or TB) transmitted in reference time slot (or duration) 500, when the feedback bit of at least one of the uplink signals 511 and 512 (PUSCH or TB) is ACK 516 (or 0 or 1), the terminal can adjust (or change or configure) the contention window value to an initial value (or minimum value) or maintain the current contention window value. As another example, when the bit information of one or more uplink signals 511 and 512 (PUSCH or TB) transmitted in reference time slot (or duration) 500 is NACK (or 1 or 1), the terminal can increase the contention window value to the next contention window value. Furthermore, when one or more uplink signals (TB or PUSCH) determined to be NACK in the received CG-DFI bitmap are configured for licensed transmission, the terminal can perform a retransmission. Here, the terminal may not perform retransmissions for licensed (or scheduled) uplink signals.

[0168] [Examples 1-2] Competition Window Value Adjustment Based on CBG Units

[0169] When the bitmap information included in the received CG-DFI is determined, the terminal can determine that each bit of the bitmap represents ACK / NACK information based on CBG. Specifically, the terminal can determine the adjustment (or change or configuration) of the contention window value by converting each of one or more bits 515 and 516 in the bitmap information included in the received CG-DFI for one or more uplink signals 511 and 512 (PUSCH or TB) transmitted in the reference time slot (or duration) 500 into ACK / NACK information based on CBG. For example, when the received feedback bits 515 and 516 for one or more uplink signals 511 and 512 (PUSCH or TB) transmitted in the reference time slot (or duration) 500 are ACK and NACK, the terminal can determine "ACK ACK" and "NACK NACK" (which are ACK / NACK in units of CBG). Here, the terminal can adjust (or change or configure) the contention window value based on the ratio of ACK and NACK in units of CBG. When at least 10% of the CBG-based ACK / NACK messages are ACKs, the terminal can adjust (or change or configure) the contention window value to its initial value (or minimum value) or maintain the current contention window value. When at least 10% (or 10% or less) of the CBG-based ACK / NACK messages are not ACKs, the terminal can increase the contention window value to the next contention window value. Furthermore, when one or more uplink signals (TB or PUSCH) determined to be NACKs in the received CG-DFI bitmap are configured for licensed transmission, the terminal can perform retransmission on the uplink signals. Here, the terminal may not perform retransmission on licensed (or scheduled) uplink signals. According to embodiments 1-2, there is an advantage in increasing the probability of minimizing the terminal's contention window value.

[0170] According to embodiments of this disclosure, the base station can configure the operation according to the embodiments via L1 or higher layer signaling. Furthermore, the contention window value can be adjusted in conjunction with the embodiments. For example, embodiments 1-2 can be applied to determine the HARQ information bits of uplink signals transmitted in a reference time slot (or duration), and embodiments 1-1 can be applied to determine the HARQ information bits of other uplink signals.

[0171] [Example 2]

[0172] In this embodiment, a method for a base station to indicate ACK / NACK transmission information for all HARQ processes using a bitmap and a method for a terminal to determine the received ACK / NACK information will be described for base stations and terminals operating in unlicensed frequency bands.

[0173] Regarding base stations and terminals transmitting / receiving signals in unlicensed frequency bands, it is assumed that the terminal is configured to perform PUCCH / PUSCH transmissions in one or more time slots via a licensed configuration. Furthermore, the terminal can perform PUCCH / PUSCH transmissions in at least one or more time slots via a licensed configuration from the base station. When receiving a licensed transmission configuration from the base station, the terminal can add a HARQ process number to the uplink control signal and transmit this uplink control signal simultaneously with the PUSCH transmission. Here, the HARQ process number used for licensed transmissions can be assigned by the base station and can also be used for license-based (scheduled) transmissions. Simultaneously, the base station can configure the terminal with CBG-based uplink transmissions. When decoding CBG-based uplink signals, the base station can determine whether the transmission was successful or failed while performing decoding on each code block. Furthermore, the base station can configure whether to operate a bitmap for configuring DFI based on a TB indicating HARQ-ACK feedback in 1 bit for each HARQ process or based on a CBG indicating HARQ-ACK feedback for one or more CBGs for each HARQ process via L1 or higher layer signaling (e.g., SIB, MIC, MAC-CE, or RRC signaling).

[0174] Figure 6 This is a diagram illustrating another embodiment of the present disclosure.

[0175] exist Figure 6 In this case, assume that the base station configures the size of the CBG to 2 through higher-layer signaling.

[0176] The base station can receive uplink signals (PUSCH or TB) based on CBG from the terminal. Furthermore, the base station can decode the received CBG-based uplink signals in units of CBG. When generating HARQ-ACK information bits (or HARQ process numbers) for the uplink signals, the base station can determine a method for adjusting the terminal's contention window value based on the CBG decoding results. For example, as a result of the base station decoding one or more CBGs of uplink signals 611 and 612 (TB or PUSCH) received from the terminal in reference time slot (or duration) 600, when at least 10% of the CBGs are determined to be ACK or one or more uplink signals (TB or PUSCH) are determined to be ACK, the base station can expect the terminal to adjust (or change or configure) the terminal's contention window value to an initial value (or minimum value) or maintain the current contention window value.

[0177] As another example, as a result of the base station decoding one or more CBGs of uplink signals 611 and 612 (TB or PUSCH) received from the terminal in reference time slot (or duration) 600, when at least 10% of the CBGs are not determined to be ACK or all uplink signals (TB or PUSCH) are determined to be NACK, the base station can expect the terminal to increase the contention window value to the next contention window value. Here, considering the method by which the terminal adjusts the contention window value, the base station can generate feedback information bits (or HARQ process numbers) for the uplink signals. For example, as a result of the base station decoding one or more uplink signals 611 and 612 received in reference time slot (or duration) 600, when indicating a change in the terminal's contention window value towards an initial value (or minimum value), the base station can generate all ACK (or 1 or 0) HARQ-ACK information bits for one or more uplink signals 611 and 612 received in reference time slot (or duration) 600.

[0178] As another example, as a result of the base station decoding one or more uplink signals 611 and 612 received in reference time slot (or duration) 600, when it is necessary to indicate an increase in the contention window value of the terminal, the base station may generate all NACK (or 0 or 1) HARQ-ACK information bits of one or more uplink signals 611 and 612 received in reference time slot (or duration) 600.

[0179] According to another embodiment, a method for adjusting the terminal's contention window value can be indicated by configuring a specific bit combination via L1 or higher layer signaling, or by configuring a preset bit configuration. Here, the size of the specific bit can be equal to the number of uplink signals transmitted in the reference time slot (or duration). The terminal can adjust its contention window value by using bit information corresponding to the reference time slot (or duration) in the bitmap of the received CG-DFI. Here, the terminal may perform retransmissions (or add adjustment information to the terminal's contention window value) without based on the bit information corresponding to the reference time slot (or duration).

[0180] In this embodiment, a method for a base station to generate HARQ-ACK information bits for uplink signals transmitted in a reference time slot (or duration) has been described; however, this method can be applied to all time slots. Alternatively, this method can be applied only to licensed uplink transmissions or configuration-licensed uplink transmissions.

[0181] [Example 3]

[0182] In this embodiment, a method for adjusting the contention window value based on the UL-licensed DCI received by a base station and terminal operating in an unlicensed frequency band will be described.

[0183] Regarding base stations and terminals transmitting / receiving signals in unlicensed frequency bands, it is assumed that the terminal is configured to perform PUCCH / PUSCH transmissions in one or more time slots via a configuration grant setting. Furthermore, the terminal can transmit PUCCH / PUSCH in at least one or more time slots via a configuration grant setting from the base station. When receiving the configuration grant transmission from the base station, the terminal can add a HARQ process number to the uplink control signal and transmit this uplink control signal simultaneously with the PUSCH transmission. Here, the HARQ process number used for configuration grant transmissions can be assigned by the base station and can also be used for license-based (scheduled) transmissions. Simultaneously, the base station can configure the terminal with CBG-based uplink transmissions. When decoding CBG-based uplink signals, the base station can determine whether the transmission was successful or failed while performing decoding on each code block.

[0184] Figure 7 This is a diagram illustrating another embodiment of the present disclosure.

[0185] exist Figure 7 In this case, assume that the base station configures the size of the CBG to 2 through higher-layer signaling.

[0186] The base station can send CG-DFI 707 to the terminal by configuring feedback for uplink signals to the terminal in the bitmap. The terminal can perform contention window value adjustment based on the bitmap information of the CG-DFI received from the base station. Simultaneously, after sending CG-DFI 707 to the terminal, the base station can send UL Authorization DCI 708 instructing the terminal for uplink retransmission or initial transmission, and the UL Authorization DCI may include ACK / NACK information in TB or CBG units. Here, it is assumed that the terminal receives UL Authorization DCI 708 from the base station after increasing the contention window value using the information included in CG-DFI 707. Furthermore, it is assumed that the UL Authorization DCI 708 received by the terminal includes ACK / NACK information or HARQ procedures for uplink transmission to adjust the terminal's contention window value based on the bitmap information of CG-DFI 707. When the ACK / NACK information (or contention window value adjustment information) received from CG-DFI 707 and the ACK / NACK information received from UL-authorized DCI 708 are the same, the terminal may not change the contention window value determined by CG-DFI 707. When the ACK / NACK information (or contention window value adjustment information) received from CG-DFI 707 and the ACK / NACK information received from UL-authorized DCI 708 are different from each other, the terminal may adjust the contention window value as follows.

[0187] [Example 3-1]

[0188] The terminal can maintain a contention window value adjusted using information included in the pre-received CG-DFI 707. In other words, ACK / NACK information included in the UL-authorized DCI 708 may not be used to adjust the terminal's contention window value.

[0189] [Example 3-2]

[0190] The terminal can modify the contention window value, which has been adjusted using information included in the pre-received CG-DFI 707, based on the ACK / NACK information included in the UL-authorized DCI 708. For example, the terminal can increase the contention window value using the information included in the CG-DFI 707, and then adjust the contention window value to its initial (or minimum) value when the ACK / NACK information included in the UL-authorized DCI 708 indicates that the terminal's contention window value should be adjusted to its initial (or minimum) value. As another example, the terminal can adjust the contention window value to its initial (or minimum) value using the information included in the CG-DFI 707, and then increase the contention window value when the ACK / NACK information included in the UL-authorized DCI 708 indicates that the terminal's contention window value should be increased. Here, the terminal can increase the contention window value based on the contention window value before receiving the CG-DFI 707, or based on a contention window value adjusted to its initial (or minimum) value after receiving the CG-DFI 707. As another example, the terminal can increase the contention window value by using the information included in CG-DFI 707, and then increase the terminal's contention window value to the next value when the ACK / NACK information included in the UL Authorized DCI received by the terminal indicates that the terminal's contention window value should be increased.

[0191] [Example 3-3]

[0192] When a terminal needs to change the contention window value based on the ACK / NACK information included in the UL-authorized DCI 724, if another reference slot (or duration) 717 is configured before receiving the UL-authorized DCI 724, or if another uplink signal is sent after receiving the CG-DFI 716, the ACK / NACK information included in the UL-authorized DCI may not be used to adjust the terminal's contention window value.

[0193] [Examples 3-4]

[0194] If, before receiving CG-DFI 726, the terminal has already received an indication via UL-licensed DCI 725 for a retransmission (or CBG-based retransmission) of one or more uplink signals 714 and 715 transmitted in reference time slot (or duration) 709, or for the initial transmission of the corresponding HARQ process, the terminal can adjust the contention window value based on UL-licensed DCI 725. Here, the ACK / NACK information (or contention window adjustment information) received from DFI may not be used or may not be expected to be received.

[0195] [Example 4]

[0196] In this embodiment, regarding the base station and terminal transmitting / receiving signals in an unlicensed frequency band, it is assumed that the terminal is configured to perform PUSCH transmissions in one or more time slots (or symbols) through a configuration grant configuration. When receiving the configuration grant transmission from the base station, the terminal can add a HARQ process number to the uplink control signal and transmit the uplink control signal simultaneously with the PUSCH transmission. Here, the HARQ process number used for configuring the grant transmission can be assigned by the base station and can also be used for license-based (scheduled) transmissions. Simultaneously, the base station can configure the terminal to transmit CBG-based uplink signals via higher-layer (or L1 or DCI) signaling. When decoding the TB of the uplink signal received from the terminal, the base station can determine whether the transmission was successful or failed while performing decoding on each code block. Here, the terminal can determine that the CBG-based uplink signal transmission configured via higher-layer (or L1) signaling from the base station corresponds only to uplink signal transmissions scheduled by the DCI. In other words, during configuration grant-based uplink transmissions in the unlicensed frequency band, the terminal may not perform CBG-based uplink signal transmissions. According to another embodiment, in unlicensed frequency bands, the base station can configure CBG-based uplink signal transmission for the terminal without using higher-layer (or L1) signaling. In other words, the terminal may not expect the base station to configure CBG-based uplink signal transmission in unlicensed frequency bands.

[0197] Meanwhile, when the base station has already configured the terminal to send CBG-based uplink signals via higher-layer (or L1 or DCI) signaling, the terminal may not perform configuration-authorized uplink (or scheduled uplink) transmission based on DFI bit information. The terminal can adjust its contention window value using only the DFI bit information. For example, even if the DFI feedback for a specific HARQ process number indicates NACK, the contention window value can be increased without performing a retransmission.

[0198] Figure 8 This is a flowchart illustrating the operation of a base station according to an embodiment of the present disclosure.

[0199] Now refer to Figure 8The operation of the base station is described. In operation 800, the base station can send configurations for PDCCH, PDSCH, PUCCH, and PUSCH transmission / reception to the terminal via higher-layer signaling. For example, the base station can send the PDCCH resource area, CORESET configuration, or search space configuration for receiving downlink or uplink scheduling information to the terminal via higher-layer signaling. Furthermore, the base station can send the configurations for PDSCH / PUSCH transmission / reception to the terminal via higher-layer signaling, including offset information between the PDCCH receive slot and the PDSCH receive slot or PUSCH transmit slot, as well as information about the number of times the PDSCH or PUSCH is repeatedly transmitted. Additionally, the base station can send the terminal configuration information for scheduling multiple PUSCHs through a single DCI, interleaving structure configuration, and configuration information about the subcarrier spacing used during downlink reception or uplink transmission via higher-layer signaling. In operation 810, the base station can additionally send configuration information related to configuration grants, such as configuration grant transmission period and offset information. Furthermore, configuration information related to the CBG size for CBG-based uplink transmissions can be sent. Here, the configuration authorization information and CBG-based uplink configuration information sent to the terminal in operation 810 can be sent in operation 800 instead. In operation 820, the base station can additionally configure configuration information regarding the method of configuring the DFI bitmap, and operation 820 can be omitted when the relevant configuration information is pre-configured. When the terminal does not send CBG-based uplink signals in operation 830, in operation 840, the base station can configure the DFI bitmap based on TB-based ACK / NACK information. When the terminal sends CBG-based uplink signals in operation 830, the base station can configure the DFI bitmap for contention window value adjustment configuration of the terminal based on the method of configuring the DFI bitmap configured to the terminal in operation 820, and send it to the terminal in operation 850.

[0200] Figure 9 This is a flowchart illustrating the operation of a terminal according to an embodiment of the present disclosure.

[0201] In operation 900, the terminal receives configurations for PDCCH, PDSCH, PUCCH, and PUSCH transmission / reception from the base station via higher-layer signaling, and configures the PDCCH, PDSCH, PUCCH, and PUSCH transmission / reception according to the received configuration information. For example, the terminal can receive PDCCH resource areas, CORESET configurations, or search space configurations via higher-layer signaling for receiving downlink or uplink scheduling information from the base station. Furthermore, the terminal can be configured by the base station via higher-layer signaling with configuration information for scheduling multiple PUSCHs through a single DCI, interleaving structure configurations, and subcarrier spacing information used during downlink reception or uplink transmission. In operation 910, the terminal can additionally configure configuration information related to configuration grants, such as configuration grant transmission periods and offset information. Additionally, the terminal can additionally configure configuration information related to the CBG size of CBG-based uplink transmissions. Here, the configuration grant-related configuration information and CBG-based uplink configuration information in operation 910 can be alternatively included in the higher-layer signaling configuration information transmitted in operation 900. In operation 920, the terminal can be configured with configuration information regarding the method for configuring the DFI bitmap by the base station, and operation 920 can be omitted if the relevant configuration information is pre-configured. When the terminal does not transmit CBG-based uplink signals in operation 930, in operation 940, the terminal can determine that the DFI bitmap received from the base station represents ACK / NACK in TB units. When the terminal transmits CBG-based uplink signals in operation 930, the terminal can determine the DFI bitmap received from the base station in operation 950 based on the method configured in operation 920 or a pre-configured method, and adjust the terminal's contention window value.

[0202] According to embodiments of this disclosure, a wireless communication system, specifically a system and node for transmitting / receiving signals based on CBG transmission information via an unlicensed frequency band, generates feedback bit information of the received signal according to the purpose of the feedback to be transmitted, thereby enabling more efficient transmission / reception of HARQ-ACK feedback.

[0203] Figure 10 This is a block diagram illustrating the structure of a base station according to an embodiment of the present disclosure.

[0204] refer to Figure 10According to embodiments of this disclosure, a base station may include a base station receiver 1000, a base station transmitter 1010, and a base station processor 1020. In embodiments of this disclosure, the base station receiver 1000 and the base station transmitter 1010 may be collectively referred to as a transceiver. The transceiver may transmit signals to or receive signals from a terminal. These signals may include control information and data. In this regard, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low-noise amplification and down-converting the frequency of the received signal. Furthermore, the transceiver may receive signals via a wireless channel and output them to the base station processor 1020, and transmit signals output from the base station processor 1020 via a wireless channel. The base station processor 1020 may control a series of processes that cause the base station to operate according to the embodiments disclosed above. For example, the base station receiver 1000 may receive data signals including control signals transmitted by a terminal, and the base station processor 1020 may determine the reception result for the data signals and control signals transmitted by the terminal. As another example, the base station processor 1020 may perform a channel access procedure on an unlicensed frequency band. In detail, for example, base station receiver 1000 can receive signals transmitted through an unlicensed frequency band, and base station processor 1020 can determine whether the unlicensed frequency band is idle by comparing the strength of the received signal with a threshold, which is predefined or determined based on a function value with bandwidth as a factor. As another example, base station processor 1020 can configure or change the base station's DCI to indicate the release or activation of type 2CG-PUSCH scheduling. As another example, when base station receiver 1000 receives information from a terminal about the downlink transmission interval in the channel occupancy interval of an unlicensed frequency band, base station processor 1020 can reconfigure or change the downlink control and data channel transmission time or period of the base station, and therefore, base station transmitter 1010 can transmit downlink control and data channels. Furthermore, base station processor 1020 can generate a DFI bitmap based on the result of base station receiver 1000 receiving data signals from the terminal. Here, base station transmitter 1010 can send the DFI generated by base station processor 1020 to the terminal.

[0205] Figure 11 This is a block diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0206] refer to Figure 11The terminal according to embodiments of this disclosure may include a terminal receiver 1100, a terminal transmitter 1110, and a terminal processor 1120. In embodiments of this disclosure, the terminal receiver 1100 and the terminal transmitter 1110 may be collectively referred to as a transceiver. The transceiver may transmit signals to or receive signals from a base station. These signals may include control information and data. In this regard, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low-noise amplification and down-converting the frequency of the received signal. Furthermore, the transceiver may receive signals via a wireless channel and output them to the terminal processor 1120, and transmit signals output from the terminal processor 1120 via a wireless channel. The terminal processor 1120 may control a series of processes causing the terminal to operate according to the embodiments disclosed above. For example, the terminal receiver 1100 may receive a data signal including control signals, and the terminal processor 1120 may determine the reception result for the data signal. Next, when it is necessary to transmit a first signal reception result including data reception at a certain timing to the base station, the terminal transmitter 1110 may transmit a first signal reception signal to the base station at a timing determined by the processor. As another example, when terminal receiver 1100 receives information from the base station regarding the uplink or downlink transmission interval within the channel occupancy interval of an unlicensed frequency band, terminal processor 1120 can reconfigure or change the downlink control channel transmission time or period of the terminal, or the terminal can reconfigure or change the time-domain allocation information of the scheduled uplink data channel, and thus, terminal receiver 1100 can receive the downlink control channel transmitted by the base station. Furthermore, the terminal can receive the reception result for the uplink data transmitted by terminal receiver 1100 from the base station, and terminal processor 1120 can maintain or change the size of the contention window used in the channel access process for unlicensed frequency band signal transmission based on the reception result. Additionally, terminal receiver 1100 receives the DFI and related information transmitted by the base station, and terminal processor 1120 determines the DFI bitmap based on the received DFI determination information or pre-configured DFI determination information. Furthermore, terminal processor 1120 can adjust the contention window value of the terminal based on the determined DFI bitmap information.

[0207] The methods described in the claims or specification of this disclosure can be implemented in hardware, software, or a combination of hardware and software.

[0208] When implemented in software, a computer-readable storage medium may be provided to store one or more programs (e.g., software modules). The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions that direct the electronic device to perform methods according to embodiments of this disclosure as described in claims and the specification.

[0209] The program (e.g., a software module or software) can be stored in random access memory (RAM), non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), disk storage devices, optical discs (CD-ROM), digital versatile discs (DVDs), other optical storage devices, or magnetic tape. Alternatively, the program can be stored in a memory that includes a combination of some or all of the above storage media. Multiple such memories may be included.

[0210] Furthermore, the program can be stored in an attachable storage device that can be accessed via any or a combination of communication networks such as the Internet, intranet, local area network (LAN), wide area network (WLAN), and storage area network (SAN). Such a storage device can access electronic devices via an external port. Additionally, attached storage devices on the communication network can access apparatuses executing embodiments of this disclosure.

[0211] In the foregoing embodiments of this disclosure, the elements included in this disclosure are represented in singular or plural form according to specific embodiments. However, the singular or plural form is suitably chosen for situations assumed for ease of description, and this disclosure is not limited to singular or plural forms. An element expressed in singular form may include multiple elements, while an element expressed in plural form may include a single element.

[0212] The embodiments described herein are merely for the purpose of readily illustrating the technical content of this disclosure and promoting understanding of it, and are not intended to limit the scope of this disclosure. That is, it will be apparent to those skilled in the art that various modifications can be made based on the technical spirit of this disclosure. Furthermore, these embodiments can be combined with each other as needed. For example, a portion of one embodiment of this disclosure and a portion of another embodiment of this disclosure can be combined with each other to enable the base station and terminal to operate. In addition, other modifications based on the technical ideas of the embodiments can be implemented on various systems (such as FDD LTE systems, TDD LTE systems, 5G or NR systems, etc.).

Claims

1. An operation method performed by a base station in a wireless communication system, the operation method comprising: Determine configuration authorization - downlink feedback information CG-DFI; as well as Downlink control information (DCI) is sent to the terminal. The DCI includes the CG-DFI, and the CG-DFI includes at least one hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback for a first physical uplink shared channel (PUSCH). Wherein, the HARQ-ACK feedback of the at least one first PUSCH is associated with the CG-DFI, wherein the at least one PUSCH is associated with a PUSCH based on the code block group CBG and a contention window value, and wherein the HARQ-ACK feedback corresponds to the at least one PUSCH in the reference duration. Where, if at least 10% of the HARQ-ACK feedbacks are ACKs, the contention window value is a minimum value associated with the channel access priority level, and Where, if not at least 10% of the HARQ-ACK responses are ACK, the contention window value is adjusted from the current value associated with the channel access priority level to the next higher value associated with the channel access priority level.

2. The operating method according to claim 1 further includes: Based on the contention window value, uplink data is received from the terminal via the at least one first PUSCH.

3. The operating method according to claim 1, wherein, The channel access priority level is associated with the allowed contention window value.

4. An operation method performed by a terminal in a wireless communication system, the operation method comprising: Receive downlink control information (DCI) from the base station. The DCI includes configuration authorization-downlink feedback information (CG-DFI). The CG-DFI includes at least one hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback of a first physical uplink shared channel (PUSCH). HARQ-ACK feedback for the at least one first PUSCH is identified based on the CG-DFI, wherein the at least one first PUSCH is associated with a PUSCH and contention window value based on code block group CBG, and wherein the HARQ-ACK feedback corresponds to at least one PUSCH in the reference duration. If at least 10% of the HARQ-ACK responses are ACK, the contention window value is adjusted to the minimum value associated with the channel access priority level; and If not at least 10% of the HARQ-ACK responses are ACK, the contention window value is adjusted from the current value associated with the channel access priority level to the next higher value associated with the channel access priority level.

5. The operating method according to claim 4 further includes: Based on the aforementioned contention window value, PUSCH transmission is performed.

6. The operating method according to claim 4, wherein, The channel access priority level is associated with the allowed contention window value.

7. A base station in a wireless communication system, the base station comprising: transceiver; and At least one processor is configured as follows: Determine the configuration authorization - downlink feedback information CG-DFI, and The transceiver transmits downlink control information (DCI) to the terminal. The DCI includes the CG-DFI, and the CG-DFI includes at least one hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback for a first physical uplink shared channel (PUSCH). The HARQ-ACK feedback of at least one first PUSCH is associated with the CG-DFI. The at least one PUSCH is associated with a PUSCH based on the code block group CBG and a contention window value. Wherein, the HARQ-ACK feedback corresponds to at least one first PUSCH during the reference duration, Where, if at least 10% of the HARQ-ACK feedbacks are ACKs, the contention window value is a minimum value associated with the channel access priority level, and Where, if not at least 10% of the HARQ-ACK responses are ACK, the contention window value is adjusted from the current value associated with the channel access priority level to the next higher value configured for the channel access priority level.

8. A terminal in a wireless communication system, the terminal comprising: transceiver; and At least one processor is configured as follows: Receive downlink control information (DCI) from the base station. The DCI includes configuration authorization-downlink feedback information (CG-DFI). The CG-DFI includes at least one hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback of a first physical uplink shared channel (PUSCH). HARQ-ACK feedback for the at least one first PUSCH is identified based on the CG-DFI, wherein the at least one PUSCH is associated with a PUSCH based on the code block group CBG and a contention window value, and wherein the HARQ-ACK feedback corresponds to the at least one first PUSCH during the reference duration. If at least 10% of the HARQ-ACK responses are ACKs, the contention window value is adjusted to the minimum value associated with the channel access priority level, and If not at least 10% of the HARQ-ACK responses are ACK, the contention window value is adjusted from the current value associated with the channel access priority level to the next higher value associated with the channel access priority level.

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