Method and device for downlink carrier switching in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. A method performed by a user equipment (UE) in a communication system, according to one embodiment of the present disclosure, comprises the steps of: receiving, from a base station, configuration information including a bitmap related to a downlink switching pattern for a plurality of slots; identifying a cell corresponding to a first slot on the basis of the bitmap; and receiving, from the base station, a downlink channel or a downlink signal in the first slot on the cell corresponding to the first slot, wherein if a bit value corresponding to the first slot in the bitmap is a first value, the first slot may correspond to a first cell, and if the bit value corresponding to the first slot in the bitmap is a second value, the first slot may correspond to a second cell.

Description

Method and device for changing downlink carrier in a wireless communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, it relates to a method for changing a downlink carrier and an apparatus capable of performing the same.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz band (e.g., the 3 terahertz (3 THz) band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as the operation of multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for the reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.

[0004] Currently, discussions are underway to improve and enhance the performance of the initial 5G mobile communication technology, taking into account the services that the 5G mobile communication technology was intended to support. Additionally, standardization of the physical layer is in progress for technologies such as V2X (Vehicle-to-Everything), which helps autonomous vehicles make driving decisions and enhance user convenience based on their own location and status information transmitted by the vehicle; NR-U (New Radio Unlicensed), which aims for system operation in unlicensed bands to comply with various regulatory requirements; NR terminal low power consumption technology (UE Power Saving); Non-Terrestrial Network (NTN), which is direct terminal-satellite communication for securing coverage in areas where communication with the terrestrial network is impossible; and positioning.

[0005] In addition, standardization is underway in the field of wireless interface architecture / protocols for technologies such as the Industrial Internet of Things (IoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) which provides nodes to expand network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover (CHO) and Dual Active Protocol Stack (DAPS) handover, and 2-step Random Access (2-step RACH for NR) which simplifies random access procedures. Standardization is also underway in the field of system architecture / services for 5G baseline architectures (e.g., Service based Architecture, Service based Interface) for the integration of Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC), which provides services based on the location of the terminal.

[0006] When such 5G mobile communication systems are commercialized, connected devices, which are increasing explosively, will be connected to communication networks. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] Furthermore, the advancement of these 5G mobile communication systems encompasses multi-antenna transmission technologies such as new waveforms, Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas to guarantee coverage in the terahertz band of 6G mobile communication technology; metamaterial-based lenses and antennas; high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM); and Reconfigurable Intelligent Surface (RIS) technology to improve terahertz band signal coverage; as well as full-duplex technology for enhancing frequency efficiency and system networks in 6G mobile communication technology; AI-based communication technologies that realize system optimization by utilizing satellites and Artificial Intelligence (AI) from the design stage and internalizing end-to-end AI support functions; and the realization of services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could serve as a foundation for the development of next-generation distributed computing technologies.

[0008] As a result of the aforementioned developments and advancements in mobile communication systems, it has become possible to provide a variety of services, and thus measures to effectively provide these services are required.

[0009] The present disclosure aims to provide an apparatus and method capable of effectively providing services in a mobile communication system.

[0010] A method performed by a user device (UE) of a communication system according to one embodiment of the present disclosure includes receiving configuration information from a base station including a bitmap related to a downlink switching pattern for a plurality of slots, identifying a cell corresponding to a first slot based on the bitmap, and receiving a downlink channel or a downlink signal from the base station on the cell corresponding to the first slot in the first slot, wherein if the bit value corresponding to the first slot in the bitmap is a first value, the first slot corresponds to a first cell, and if the bit value corresponding to the first slot in the bitmap is a second value, the first slot may correspond to a second cell.

[0011] A method performed by a base station of a communication system according to one embodiment of the present disclosure includes the steps of: transmitting configuration information including a bitmap related to a downlink switching pattern for a plurality of slots to a user device (UE); and transmitting a downlink channel or a downlink signal to the UE on a cell corresponding to the first slot in the first slot, wherein if the bit value corresponding to the first slot in the bitmap is a first value, the first slot corresponds to a first cell, and if the bit value corresponding to the first slot in the bitmap is a second value, the first slot may correspond to a second cell.

[0012] A user device (UE) according to one embodiment of the present disclosure comprises at least one transceiver, at least one processor connected to communicate with the at least one transceiver, and a memory connected to communicate with the at least one processor and capable of executing the at least one processor individually or in any combination thereof, wherein the UE receives configuration information from a base station including a bitmap related to a downlink switching pattern for a plurality of slots, identifies a cell corresponding to a first slot based on the bitmap, and stores an instruction to receive a downlink channel or a downlink signal from the base station on the cell corresponding to the first slot in the first slot, and when the bit value corresponding to the first slot in the bitmap is a first value, the first slot corresponds to a first cell, and when the bit value corresponding to the first slot in the bitmap is a second value, the first slot may correspond to a second cell.

[0013] A base station according to one embodiment of the present disclosure comprises at least one transceiver, at least one processor connected to communicate with the at least one transceiver, and a memory connected to communicate with the at least one processor and capable of executing the at least one processor individually or in any combination thereof, wherein the base station transmits configuration information including a bitmap associated with a downlink switching pattern for a plurality of slots to a user device (UE), and in the first slot, a downlink channel or downlink signal on a cell corresponding to the first slot is transmitted to the UE, wherein if the bit value corresponding to the first slot in the bitmap is a first value, the first slot corresponds to a first cell, and if the bit value corresponding to the first slot in the bitmap is a second value, the first slot may correspond to a second cell.

[0014] The disclosed embodiments can provide an apparatus and method capable of effectively providing services in a mobile communication system.

[0015] FIG. 1 is a diagram illustrating the basic structure of the time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0016] FIG. 2 is a drawing illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0017] FIG. 3 is a drawing illustrating an example of a bandwidth portion setting in a wireless communication system according to one embodiment of the present disclosure.

[0018] FIG. 4 is a diagram illustrating an example of setting a control area of ​​a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0019] FIG. 5 is a diagram illustrating the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0020] FIG. 6 is a diagram illustrating a method for transmitting and receiving data by a base station and a terminal in consideration of a downlink data channel and rate matching resources according to one embodiment of the present disclosure.

[0021] FIG. 7 is a diagram illustrating an example of frequency axis resource allocation of a physical downlink shared channel (PDSCH) in a wireless communication system according to one embodiment of the present disclosure.

[0022] FIG. 8 is a diagram illustrating an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0023] FIG. 9 is a diagram illustrating an example of time-axis resource allocation according to the subcarrier interval of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

[0024] FIG. 10 is a diagram illustrating the wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, or dual connectivity situation according to one embodiment of the present disclosure.

[0025] FIG. 11 is a drawing illustrating downlink carrier switching according to one embodiment of the present disclosure.

[0026] FIG. 12a is a drawing illustrating an example of a Type-1 HARQ-ACK codebook for transmitting a HARQ-ACK of a PDSCH according to one embodiment of the present disclosure.

[0027] FIG. 12b is a drawing illustrating an example of a Type-1 HARQ-ACK codebook for transmitting a HARQ-ACK of a PDSCH according to one embodiment of the present disclosure.

[0028] FIG. 12c is a drawing illustrating an example of a Type-1 HARQ-ACK codebook for transmitting a HARQ-ACK of a PDSCH according to one embodiment of the present disclosure.

[0029] FIG. 13 is a simplified diagram illustrating the design flowchart of a conventional semi-static HARQ-ACK codebook according to one embodiment of the present disclosure.

[0030] FIG. 14 is a diagram showing PDSCH reception and HARQ-ACK transmission when two cells are switched every 2 slots according to one embodiment of the present disclosure.

[0031] FIG. 15 is a diagram illustrating a flowchart according to the first method of the present disclosure.

[0032] FIG. 16 is a diagram illustrating a flowchart according to the third method of the present disclosure.

[0033] FIG. 17 is a drawing illustrating invalid symbols according to one embodiment of the present disclosure.

[0034] FIG. 18 is a diagram illustrating a flowchart according to the fourth method of the present disclosure.

[0035] FIG. 19 is a diagram illustrating a method for transmitting a Type-3 HARQ-ACK codebook according to one embodiment of the present disclosure.

[0036] FIG. 20 is a diagram illustrating a method for transmitting an enhanced Type-3 HARQ-ACK codebook according to one embodiment of the present disclosure.

[0037] FIG. 21 is a diagram illustrating a case where two cells share a HARQ process ID according to one embodiment of the present disclosure.

[0038] FIG. 22 is a drawing illustrating a case where PDCCH monitoring is set in two cells according to one embodiment of the present disclosure.

[0039] FIG. 23 is a diagram illustrating the activation and deactivation of DL switching according to the activation and deactivation of SCell according to one embodiment of the present disclosure.

[0040] FIG. 24 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0041] FIG. 25 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0042] Efforts are being made to develop improved 5G or pre-5G communication systems to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems. For this reason, 5G or pre-5G communication systems are referred to as systems beyond the 4G network or systems following the LTE system. To achieve high data transmission rates, the implementation of 5G communication systems in the mmWave band (e.g., the 60 GHz band) is being considered. To mitigate path loss and increase transmission distance in the mmWave band, technologies such as beamforming, massive MIMO, full Dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antennas are being discussed for 5G communication systems. In addition, to improve the network of the system, the development of technologies such as advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation is taking place in 5G communication systems.In addition, advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non-orthogonal multiple access), and SCMA (sparse code multiple access) are being developed in 5G systems.

[0043] Meanwhile, the Internet is evolving from a human-centered network where humans generate and consume information into an IoT (Internet of Things) network where distributed components, such as objects, exchange and process information. IoE (Internet of Everything) technology, which combines IoT with Big Data processing technologies through connections with cloud servers, is also emerging. To implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required; consequently, technologies such as sensor networks, Machine-to-Machine (M2M) communication, and Machine-Type Communication (MTC) are currently being researched to facilitate the connection of objects. In an IoT environment, intelligent IT services that create new value for human life by collecting and analyzing data generated from connected objects can be provided. Through the convergence and integration of existing IT technologies with various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0044] Accordingly, various attempts are being made to apply 5G communication systems (5th generation communication systems or New Radio (NR)) to IoT networks. For example, technologies such as sensor networks, Machine to Machine (M2M), and Machine Type Communication (MTC) are being implemented using 5G communication technologies such as beamforming, MIMO, and array antennas. The application of cloud radio access networks (cloud RAN) as the big data processing technology described earlier can also be considered an example of the convergence of 3G and IoT technologies.

[0045] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0046] In describing the embodiments, technical details that are well known in the art to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0047] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the dimensions of each component do not entirely reflect their actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference numbers.

[0048] The advantages and features of the present disclosure, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration might unnecessarily obscure the essence of the present disclosure, such detailed description is omitted. Additionally, the terms described below are defined considering their functions in the present disclosure, and these may vary depending on the intentions or conventions of the user or operator. Therefore, their definitions should be based on the content throughout the specification.

[0049] Hereinafter, the base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. The terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. In this disclosure, the Downlink (DL) refers to the wireless transmission path of a signal transmitted by the base station to the terminal, and the Uplink (UL) refers to the wireless transmission path of a signal transmitted by the terminal to the base station. Furthermore, while LTE (Long-Term Evolution), LTE-A (LTE-Advanced), or 5G systems may be described as examples below, embodiments of this disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. Furthermore, the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure, at the discretion of a person with skilled technical knowledge.

[0050] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing instruction means to perform the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that perform a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer can also provide steps for executing the functions described in the flowchart block(s).

[0051] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order according to their corresponding functions.

[0052] In this embodiment, the term "part" refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or configured to run one or more processors. Thus, as an example, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs (central processing units) within the device or secure multimedia card. Also, in the embodiments, the 'parts' may include one or more processors.

[0053] Wireless communication systems are evolving from providing early voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards like 3GPP’s HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2’s HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE’s 802.16e.

[0054] As a representative example of the above-mentioned broadband wireless communication system, the LTE system employs the Orthogonal Frequency Division Multiplexing (OFDM) method for the downlink (DL) and the Single Carrier Frequency Division Multiple Access (SC-FDMA) method for the uplink (UL). The uplink refers to a wireless link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B, gNode B, or base station (BS)), and the downlink refers to a wireless link through which a base station transmits data or control signals to a terminal. The above-mentioned multiple access method can distinguish the data or control information of each user by allocating and operating time-frequency resources to be sent for each user so that they do not overlap, that is, so that orthogonality is established.

[0055] As a future communication system following LTE, that is, a 5G communication system, it must be able to freely reflect the diverse requirements of users and service providers, and therefore, services that satisfy various requirements simultaneously must be supported. Services being considered for the 5G communication system include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0056] eMBB aims to provide data transmission speeds that are superior to those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20 Gbps in the downlink and 10 Gbps in the uplink from the perspective of a single base station. Furthermore, while providing these peak data rates, the 5G communication system must also provide an increased user-perceived data rate. To satisfy these requirements, it necessitates improvements in various transmission and reception technologies, including enhanced Multi-Input Multi-Output (MIMO) transmission technology. Additionally, while LTE transmits signals using a maximum bandwidth of 20 MHz in the 2 GHz band, the 5G communication system can meet the data transmission speeds required by using a frequency bandwidth wider than 20 MHz in frequency bands of 3–6 GHz or above 6 GHz.

[0057] Simultaneously, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide IoT, mMTC requires support for a large number of terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. Since IoT devices are attached to various sensors and equipment to provide communication functions, the system must be able to support a large number of terminals within a cell (e.g., 1,000,000 terminals / km²). Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in dead zones not covered by cells, such as building basements; therefore, they may require wider coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must consist of low-cost devices, and since it is difficult to frequently replace terminal batteries, a very long battery life of 10 to 15 years may be required.

[0058] Finally, URLLC is a mission-critical cellular-based wireless communication service. Examples include services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC must offer very low latency and very high reliability. For instance, services supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and simultaneously require a packet error rate of 10^-5 or less. Consequently, for services supporting URLLC, 5G systems must provide a Transmission Time Interval (TTI) smaller than other services, and design considerations may be required to allocate wide resources within the frequency band to ensure the reliability of the communication link.

[0059] The three 5G services, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted within a single system. In this case, different transmission and reception techniques and parameters may be used between the services to satisfy the different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

[0060] [NR Time-Frequency Resources]

[0061] The frame structure of the 5G system will be explained in more detail below with reference to the drawings.

[0062] Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a wireless resource domain where data or control channels are transmitted in a 5G system.

[0063] The horizontal axis of FIG. 1 represents the time domain, and the vertical axis represents the frequency domain. In the time and frequency domains, the basic unit of a resource is a resource element (RE, 101), which can be defined as one OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) on the time axis and one subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form a single resource block (Resource Block, RB, 104). In the time axis, a single subframe (110) may contain multiple OFDM symbols (102). For example, the length of one subframe may be 1 ms.

[0064] FIG. 2 is a drawing illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0065] FIG. 2 illustrates an example of a frame (200), subframe (201), and slot (202) structure. One frame (200) can be defined as 10ms. One subframe (201) can be defined as 1ms, and thus one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( ))=14). A subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In one example of FIG. 2, cases where μ=0 (204) and μ=1 (205) are set as the subcarrier spacing are illustrated. When μ=0 (204), a subframe (201) may be composed of one slot (202), and when μ=1 (205), a subframe (201) may be composed of two slots (203). That is, the number of slots per subframe ( ) may vary, and accordingly, the number of slots per frame ( ) may vary. Depending on each subcarrier spacing setting μ and It can be defined by Table 1 below.

[0066]

[0067] [Bandwidth Section (BWP)]

[0068] Next, the Bandwidth Part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0069] FIG. 3 is a diagram illustrating an example of a bandwidth portion setting in a wireless communication system according to one embodiment of the present disclosure.

[0070] FIG. 3 shows an example in which the terminal bandwidth (UE bandwidth) (300) is configured into two bandwidth portions, namely bandwidth portion #1 (BWP#1) (301) and bandwidth portion #2 (BWP#2) (302). The base station may configure one or more bandwidth portions for the terminal and may configure information such as that shown in Table 2 below for each bandwidth portion.

[0071]

[0072] Of course, the above examples are not limited, and various parameters related to bandwidth portions may be configured for the terminal in addition to the above configuration information. The above information may be transmitted by the base station to the terminal via upper-layer signaling, for example, Radio Resource Control (RRC) signaling. At least one of the configured bandwidth portions may be activated. Whether a configured bandwidth portion is activated may be transmitted semi-statically from the base station to the terminal via RRC signaling or dynamically via Downlink Control Information (DCI).

[0073] According to some embodiments, prior to the Radio Resource Control (RRC) connection, the terminal may receive an Initial Bandwidth Part (Initial BWP) for initial connection from the base station via a Master Information Block (MIB). More specifically, during the initial connection phase, the terminal may receive configuration information for a Control Resource Set (CORESET) and a Search Space via the MIB, through which a PDCCH can be transmitted to receive system information required for initial connection (Remaining System Information; which may correspond to RMSI or System Information Block 1; SIB1). The Control Resource Set and Search Space configured via the MIB may each be considered as Identity (ID) 0. The base station may notify the terminal via the MIB of configuration information, such as frequency allocation information, time allocation information, and numerology, for Control Resource Set #0. Additionally, the base station may notify the terminal via the MIB of configuration information regarding the monitoring period and occasion for Control Resource Set #0, i.e., configuration information for Search Space #0. The terminal may consider the frequency region set as control region #0 obtained from the MIB as the initial bandwidth portion for initial access. In this case, the identifier (ID) of the initial bandwidth portion may be considered as 0.

[0074] The settings for the bandwidth portion supported by the 5G system can be used for various purposes.

[0075] According to one embodiment, if the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through the bandwidth portion setting. For example, by setting the frequency position of the bandwidth portion (setting information 2) to the terminal, the terminal can transmit and receive data at a specific frequency position within the system bandwidth.

[0076] Additionally, according to some embodiments, a base station may set multiple bandwidth portions for a terminal for the purpose of supporting different numerologies. For example, to support data transmission and reception using both a 15 kHz subcarrier interval and a 30 kHz subcarrier interval for a terminal, the base station may set two bandwidth portions to subcarrier intervals of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be frequency division multiplexed, and when data transmission and reception is to be performed with a specific subcarrier interval, the bandwidth portion set to that subcarrier interval may be activated.

[0077] In addition, according to one embodiment, a base station may set a bandwidth portion having different bandwidth sizes for the purpose of reducing the power consumption of the terminal. For example, if the terminal supports a very large bandwidth, such as 100 MHz, and always transmits and receives data using that bandwidth, very large power consumption may occur. In particular, in a situation where there is no traffic, performing monitoring of an unnecessary downlink control channel using a large bandwidth of 100 MHz may be very inefficient in terms of power consumption. To reduce the power consumption of the terminal, the base station may set a bandwidth portion of a relatively small bandwidth, such as 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0078] Regarding the method of configuring the bandwidth part, terminals prior to RRC connection (Connected) can receive configuration information for the Initial Bandwidth Part through the Master Information Block (MIB) during the initial connection phase. More specifically, the terminal can receive a Control Resource Set (CORESET) for a downlink control channel through which Downlink Control Information (DCI), which schedules System Information Blocks (SIB), can be transmitted, from the MIB of the Physical Broadcast Channel (PBCH). The bandwidth of the control resource set by the MIB can be considered as the Initial Bandwidth Part, and through this configured Initial Bandwidth Part, the terminal can receive the Physical Downlink Shared Channel (PDSCH) through which SIBs are transmitted. In addition to receiving SIBs, the Initial Bandwidth Part may also be utilized for Other System Information (OSI), paging, and Random Access.

[0079] [Bandwidth Section (BWP) Change]

[0080] When one or more bandwidth parts are set for a terminal, the base station may instruct the terminal to change (or switch, transition) the bandwidth part using the Bandwidth Part Indicator field within the DCI. For example, in FIG. 3, if the currently active bandwidth part of the terminal is Bandwidth Part #1 (301), the base station may instruct the terminal to Bandwidth Part #2 (302) using the Bandwidth Part Indicator within the DCI, and the terminal may perform a bandwidth part change to Bandwidth Part #2 (302) indicated by the received Bandwidth Part Indicator within the DCI.

[0081] As mentioned above, since DCI-based bandwidth portion changes can be directed by a DCI scheduling PDSCH or PUSCH, when a terminal receives a request for a bandwidth portion change, it must be able to receive or transmit the PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth portion. To this end, the standard specifies requirements for the delay time (TBWP) required for bandwidth portion changes, which can be defined, for example, as shown in Table 3.

[0082]

[0083] The requirements for bandwidth portion change delay time support Type 1 or Type 2 depending on the terminal's capability. The terminal can report the supported bandwidth portion delay time type to the base station.

[0084] In accordance with the aforementioned requirements for the bandwidth portion change delay time, if the terminal receives a DCI containing a bandwidth portion change indicator in slot n, the terminal performs a change to the new bandwidth portion indicated by the bandwidth portion change indicator in slot n+T BWP It can be completed at a time no later than that, and transmission and reception for the data channel scheduled by the corresponding DCI can be performed in the changed new bandwidth portion. If the base station intends to schedule a data channel in the new bandwidth portion, the terminal's bandwidth portion change delay time (T BWP By considering ), time-domain resource allocation for a data channel can be determined. That is, when a base station schedules a data channel with a new bandwidth portion, in the method for determining time-domain resource allocation for a data channel, the data channel can be scheduled after the bandwidth portion change delay time. Accordingly, the terminal [is notified] that the DCI instructing the bandwidth portion change is the bandwidth portion change delay time (T BWPYou may not expect to indicate a slot offset (K0 or K2) value smaller than )

[0085] If a terminal receives a DCI (e.g., DCI format 1_1 or 0_1) indicating a change in the bandwidth portion, the terminal may not perform any transmission or reception during a time interval corresponding to the time interval from the third symbol of the slot in which the PDCCH containing the said DCI was received to the beginning of the slot indicated by the slot offset value (K0 or K2) indicated by the time domain resource allocation indicator field within the said DCI. For example, if a terminal receives a DCI indicating a change in the bandwidth portion in slot n, and the slot offset value indicated by the said DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0086] [SS / PBCH Block]

[0087] Next, we will explain the SS (Synchronization Signal) / PBCH block in the 5G system.

[0088] An SS / PBCH block may refer to a physical layer channel block composed of PSS (Primary SS), SSS (Secondary SS), and PBCH. Specifically, it is as follows.

[0089] - PSS: A signal that serves as the reference for downlink time / frequency synchronization and provides some information about the cell ID.

[0090] - SSS: Serves as the reference for downlink time / frequency synchronization and provides the remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for PBCH demodulation.

[0091] - PBCH: Provides essential system information required for the transmission and reception of the terminal's data and control channels. The essential system information may include search space-related control information representing wireless resource mapping information of the control channel, scheduling control information for a separate data channel transmitting system information, etc.

[0092] - SS / PBCH block: An SS / PBCH block is composed of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks may be transmitted within a time of 5ms, and each transmitted SS / PBCH block may be distinguished by an index.

[0093] The terminal can detect PSS and SSS during the initial connection phase and can decode PBCH. The terminal can obtain MIB from PBCH and receive Control Resource Set (CORESET) #0 from it (which may correspond to a control resource set with a control resource set index of 0). The terminal can perform monitoring of Control Resource Set #0 by assuming that the selected SS / PBCH block and the Demodulation Reference Signal (DMRS) transmitted from Control Resource Set #0 are Quasi-Co-Locations (QCL). The terminal can receive system information using downlink control information transmitted from Control Resource Set #0. The terminal can obtain configuration information related to Random Access Channel (RACH) required for initial connection from the received system information. The terminal can transmit Physical RACH (PRACH) to the base station considering the selected SS / PBCH index, and the base station receiving the PRACH can obtain information regarding the SS / PBCH block index selected by the terminal. The base station can know that the terminal has selected a block among the respective SS / PBCH blocks and is monitoring the associated control area #0.

[0094] [PDCCH: DCI related]

[0095] Next, Downlink Control Information (DCI) in 5G systems will be explained in detail.

[0096] In a 5G system, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or Physical Downlink Shared Channel (PDSCH)) is transmitted from the base station to the terminal via DCI. The terminal can monitor the fallback DCI format and the non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format may consist of fixed fields predefined between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

[0097] DCI can be transmitted via the Physical Downlink Control Channel (PDCCH) after undergoing channel coding and modulation processes. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled into a Radio Network Temporary Identifier (RNTI) corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. In other words, the RNTI is not transmitted explicitly but is included in the CRC calculation process. Upon receiving a DCI message transmitted over the PDCCH, the terminal checks the CRC using the assigned RNTI; if the CRC check result is correct, the terminal knows that the message was sent to it.

[0098] For example, a DCI scheduling a PDSCH for System Information (SI) can be scrambled to SI-RNTI. A DCI scheduling a PDSCH for Random Access Response (RAR) messages can be scrambled to RA-RNTI. A DCI scheduling a PDSCH for Paging messages can be scrambled to P-RNTI. A DCI notifying a Slot Format Indicator (SFI) can be scrambled to SFI-RNTI. A DCI notifying Transmit Power Control (TPC) can be scrambled to TPC-RNTI. A DCI scheduling a terminal-specific PDSCH or PUSCH can be scrambled to C-RNTI (Cell RNTI).

[0099] DCI format 0_0 can be used as a countermeasure DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI can include, for example, the information in Table 4.

[0100]

[0101] DCI format 0_1 ​​can be used as a non-defense DCI for scheduling PUSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI can include, for example, the information in Table 5.

[0102]

[0103] DCI format 1_0 can be used as a countermeasure DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI can include, for example, the information in Table 6.

[0104]

[0105] DCI format 1_1 can be used as a non-defense DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI can include, for example, the information in Table 7.

[0106]

[0107] [PDCCH: CORESET, REG, CCE, Search Space]

[0108] In the following, the downlink control channel in a 5G communication system will be explained in more detail with reference to the drawings.

[0109] FIG. 4 is a diagram illustrating an example of setting a control area of ​​a downlink control channel in a wireless communication system according to an embodiment of the present disclosure. FIG. 4 illustrates an example of a control area (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system. FIG. 4 illustrates an example in which two control areas (Control Area #1 (401), Control Area #2 (402)) are set within a terminal bandwidth part (UE bandwidth part) (410) in the frequency axis and one slot (420) in the time axis. The control areas (401, 402) can be set in a specific frequency resource (403) within the entire terminal bandwidth part (410) in the frequency axis. The control areas (401, 402) can be set with one or more OFDM symbols in the time axis and can be defined as the control area length (Control Resource Set Duration, 404). Referring to the illustrated example in FIG. 4, control area #1 (401) is set to a control area length of 2 symbols, and control area #2 (402) is set to a control area length of 1 symbol.

[0110] The control domain in the aforementioned 5G system can be configured by the base station to the terminal through upper-layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Configuring the control domain by the base station to the terminal means that the base station provides the terminal with information such as the control domain identifier (Identity), the frequency location of the control domain, and the symbol length of the control domain. For example, it may include the information in Table 8.

[0111]

[0112] In Table 8, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information may include information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control area.

[0113] FIG. 5 is a diagram illustrating the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0114] FIG. 5 shows an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in a 5G system. According to FIG. 5, the basic unit of time and frequency resources that constitute a control channel can be called a REG (Resource Element Group, 503), and the REG (503) can be defined as 1 OFDM symbol (501) on the time axis and 1 PRB (Physical Resource Block, 502) on the frequency axis, i.e., 12 subcarriers. A base station can concatenate REGs (503) to form a downlink control channel allocation unit.

[0115] As illustrated in FIG. 5, if the basic unit to which a downlink control channel is allocated in a 5G system is called a CCE (Control Channel Element, 504), then 1 CCE (504) can be composed of multiple REGs (503). For example, the REG (503) illustrated in FIG. 5 can be composed of 12 REs, and if 1 CCE (504) is composed of 6 REGs (503), then 1 CCE (504) can be composed of 72 REs. When a downlink control area is established, the area can be composed of multiple CCEs (504), and a specific downlink control channel can be mapped to one or multiple CCEs (504) and transmitted according to the Aggregation Level (AL) within the control area. The CCEs (504) in the control area are distinguished by numbers, and the numbers of the CCEs (504) can be assigned according to a logical mapping method.

[0116] The basic unit of the downlink control channel, namely the REG (503) shown in FIG. 5, may include both the REs to which the DCI is mapped and the DMRS (505), which is a reference signal for decoding, to which the area is mapped. As shown in FIG. 5, three DMRS (505) may be transmitted within one REG (503). The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 depending on the Aggregation Level (AL), and different numbers of CCEs may be used to implement link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel may be transmitted through L CCEs. The terminal must detect the signal without knowing information about the downlink control channel, and a search space representing a set of CCEs is defined for blind decoding. A search space is a set of downlink control channel candidates consisting of CCEs that a terminal must attempt to decode at a given aggregation level, and since there are various aggregation levels that form a group of 1, 2, 4, 8, or 16 CCEs, a terminal may have multiple search spaces. A search space set can be defined as a set of search spaces at all configured aggregation levels.

[0117] Search spaces can be classified into common search spaces and UE-specific search spaces. A certain group of terminals or all terminals may examine the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling or paging messages regarding system information. For example, PDSCH scheduling allocation information for the transmission of SIBs containing cell operator information can be received by examining the common search space of the PDCCH. In the case of the common search space, since a certain group of terminals or all terminals must receive the PDCCH, it can be defined as a pre-arranged set of CCEs. Scheduling allocation information for a UE-specific PDSCH or PUSCH can be received by examining the UE-specific search space of the PDCCH. The UE-specific search space can be defined specifically as a function of the terminal's identity and various system parameters.

[0118] In a 5G system, parameters for the search space for a PDCCH can be configured from the base station to the terminal via upper-layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station may configure the terminal the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the occasion for monitoring in slot-symbol units for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the search space, and the control domain index to be monitored in the search space. For example, parameters for the search space for a PDCCH may include the information in Table 9.

[0119]

[0120] According to the configuration information, the base station may set one or multiple sets of search spaces for the terminal. According to some embodiments, the base station may set search space set 1 and search space set 2 for the terminal, and may set DCI format A scrambled with X-RNTI in search space set 1 to be monitored in a common search space, and may set DCI format B scrambled with Y-RNTI in search space set 2 to be monitored in a terminal-specific search space.

[0121] According to the configuration information, one or more sets of search spaces may exist in a common search space or a terminal-specific search space. For example, Search Space Set #1 and Search Space Set #2 may be configured as a common search space, and Search Space Set #3 and Search Space Set #4 may be configured as a terminal-specific search space.

[0122] In the common search space, the following combinations of DCI formats and RNTI can be monitored. Of course, they are not limited to the examples below.

[0123] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0124] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0125] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0126] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0127] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0128] In terminal-specific search spaces, the following combinations of DCI formats and RNTI can be monitored. Of course, they are not limited to the examples below.

[0129] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0130] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0131] The specified RNTIs may follow the definitions and uses below.

[0132] C-RNTI (Cell RNTI): Used for terminal-specific PDSCH scheduling

[0133] TC-RNTI (Temporary Cell RNTI): Used for terminal-specific PDSCH scheduling

[0134] CS-RNTI (Configured Scheduling RNTI): Used for semi-statically configured terminal-specific PDSCH scheduling.

[0135] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling during the random access phase

[0136] P-RNTI (Paging RNTI): Used for PDSCH scheduling where paging is transmitted.

[0137] SI-RNTI (System Information RNTI): Used for PDSCH scheduling where system information is transmitted.

[0138] INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH has been punctured.

[0139] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to instruct power control commands to the PUSCH

[0140] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to instruct power control commands to the PUCCH

[0141] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to instruct power regulation commands to the SRS

[0142] The aforementioned specified DCI formats may follow definitions such as the examples in Table 10.

[0143]

[0144] In a 5G system, the search space of aggregation level L in the control domain p and search space set s can be expressed as Equation 1 below.

[0145] [Mathematical Formula 1]

[0146]

[0147] - : Lamination level

[0148] - : Carrier Index

[0149] - : Total number of CCEs existing within control domain p

[0150] - : Slot Index

[0151] - : Number of PDCCH candidates at assembly level L

[0152] - = 0, ... , -1: PDCCH candidate index of aggregation level L

[0153] - = 0, ... , -1

[0154] - , , , , ,

[0155] - : Terminal identifier

[0156] The value may be 0 for the common search space.

[0157] In the case of a terminal-specific search space, the value may correspond to a value that changes according to the terminal's identity (C-RNTI or ID set by the base station for the terminal) and the time index.

[0158] In a 5G system, as multiple sets of search spaces can be configured with different parameters (e.g., the parameters in Table 9), the set of search space sets monitored by the terminal at each point in time may vary. For example, if search space set #1 is configured with an X-slot period and search space set #2 is configured with a Y-slot period and X and Y are different, the terminal may monitor both search space set #1 and search space set #2 in a specific slot, and monitor either search space set #1 or search space set #2 in a specific slot.

[0159] [PDCCH: BD / CCE limit]

[0160] When multiple sets of search spaces are configured for a terminal, the following conditions may be considered in determining the set of search spaces that the terminal must monitor.

[0161] If the terminal receives the value of monitoringCapabilityConfig-r16, which is an upper layer signaling, as r15monitoringcapability, the terminal defines the maximum value for the number of PDCCH candidates that can be monitored and the number of CCEs constituting the entire search space (where the entire search space refers to the entire set of CCEs corresponding to the union area of ​​multiple search space sets) per slot, and if the value of monitoringCapabilityConfig-r16 is received as r16monitoringcapability, the terminal defines the maximum value for the number of PDCCH candidates that can be monitored and the number of CCEs constituting the entire search space (where the entire search space refers to the entire set of CCEs corresponding to the union area of ​​multiple search space sets) per span.

[0162] [Condition 1: Limit on the maximum number of PDCCH candidates]

[0163] As described above, M is the maximum number of PDCCH candidate groups that the terminal can monitor, depending on the setting value of the upper layer signaling. μ The subcarrier interval is 15·2 μ In a cell set to kHz, if defined based on slots, follow Table 11 below, and if defined based on spans, follow Table 12 below.

[0164]

[0165]

[0166] [Condition 2: Limit on Maximum CCEs]

[0167] As described above, depending on the setting value of the upper layer signaling, C, which is the maximum number of CCEs constituting the entire search space (where the entire search space refers to the entire set of CCEs corresponding to the union area of ​​multiple search space sets), μ The subcarrier interval is 15·2 μIn a cell set to kHz, if defined based on slots, follow Table 13 below, and if defined based on spans, follow Table 14 below.

[0168]

[0169]

[0170] For the convenience of explanation, a situation in which both of the above conditions 1 and 2 are satisfied at a specific point in time is defined as "condition A". Therefore, not satisfying condition A may mean not satisfying at least one of the above conditions 1 and 2.

[0171] [PDCCH: Overbooking]

[0172] Depending on the configuration of the base station's search space sets, there may be cases where Condition A is not satisfied at a specific point in time. If Condition A is not satisfied at a specific point in time, the terminal may select and monitor only some of the search space sets configured to satisfy Condition A at that point in time, and the base station may transmit a PDCCH to the selected search space sets.

[0173] You can follow the method below to select some of the navigation spaces from the entire set of configured navigation spaces.

[0174] If condition A for PDCCH is not satisfied at a specific time point (slot), the terminal (or base station) may preferentially select a search space set with a search space type set as a common search space among the search space sets existing at that time point, over a search space set with a search space type set as a terminal-specific search space.

[0175] When all sets of search spaces configured as common search spaces have been selected (i.e., when Condition A is satisfied even after selecting all search spaces configured as common search spaces), the terminal (or base station) may select sets of search spaces configured as terminal-specific search spaces. In this case, if there are multiple sets of search spaces configured as terminal-specific search spaces, the search space set with a lower search space set index may have a higher priority. The terminal (or base station) may select sets of terminal-specific search spaces within the range where Condition A is satisfied, taking priority into consideration.

[0176] [Regarding Rate Matching / Puncturing]

[0177] In the following, the rate matching operation and puncturing operation will be described in detail.

[0178] When a time and frequency resource A intended to transmit an arbitrary symbol sequence A overlaps with an arbitrary time and frequency resource B, rate matching or puncturing operations may be considered as transmission and reception operations of channel A, taking into account the area resource C where resource A and resource B overlap. Specific operations may follow the details below.

[0179] Rate Matching Operation

[0180] - A base station may transmit a symbol sequence A to a terminal by mapping Channel A only to the remaining resource area, excluding Resource C which corresponds to the area overlapping with Resource B, from the entire Resource A. For example, if symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol #4}, Resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and Resource B is {Resource #3, Resource #5}, the base station may sequentially map and send symbol sequence A to the remaining resources {Resource #1, Resource #2, Resource #4}, excluding {Resource #3} which corresponds to Resource C within Resource A. Consequently, the base station may transmit the symbol sequence {Symbol #1, Symbol #2, Symbol #3} by mapping it to {Resource #1, Resource #2, Resource #4}, respectively.

[0181] The terminal can determine Resource A and Resource B from scheduling information regarding Symbol Sequence A from the base station, and thereby determine Resource C, which is the area where Resource A and Resource B overlap. The terminal can receive Symbol Sequence A by assuming that Symbol Sequence A was transmitted by mapping it to the remaining area of ​​Resource A, excluding Resource C. For example, if Symbol Sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol #4}, Resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and Resource B is {Resource #3, Resource #5}, the terminal can receive Symbol Sequence A by assuming that it was sequentially mapped to the remaining resources {Resource #1, Resource #2, Resource #4}, excluding {Resource #3}, which corresponds to Resource C. Consequently, the terminal can perform a series of subsequent reception operations by assuming that Symbol Sequence {Symbol #1, Symbol #2, Symbol #3} was transmitted by mapping it to {Resource #1, Resource #2, Resource #4}, respectively.

[0182] Puncturing action

[0183] If there is a resource C corresponding to an area overlapping with resource B among all resources A to which the base station intends to transmit symbol sequence A to a terminal, the base station maps symbol sequence A to the entire resource A, but does not perform transmission in the resource area corresponding to resource C, and can perform transmission only in the remaining resource area of ​​resource A excluding resource C. For example, if symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol #4}, resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource B is {Resource #3, Resource #5}, the base station can map symbol sequence A {Symbol #1, Symbol #2, Symbol #3, Symbol #4} to resource A {Resource #1, Resource #2, Resource #3, Resource #4} respectively, and transmit only the symbol sequence {Symbol #1, Symbol #2, Symbol #4} corresponding to the remaining resources {Resource #1, Resource #2, Resource #4}, excluding {Resource #3} corresponding to resource C, and may not transmit {Symbol #3} mapped to {Resource #3} corresponding to resource C. Consequently, the base station can map and transmit the symbol sequence {Symbol #1, Symbol #2, Symbol #4} to {Resource #1, Resource #2, Resource #4} respectively.

[0184] The terminal can determine resources A and B from scheduling information for symbol sequence A from the base station, and thereby determine resource C, which is the area where resources A and B overlap. The terminal can receive symbol sequence A by assuming that symbol sequence A is mapped to the entire resource A, but is transmitted only in the remaining area of ​​resource A excluding resource C. For example, if symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol #4}, resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource B is {Resource #3, Resource #5}, the terminal can assume that symbol sequence A {Symbol #1, Symbol #2, Symbol #3, Symbol #4} is mapped to resource A {Resource #1, Resource #2, Resource #3, Resource #4} respectively, but {Symbol #3} mapped to {Resource #3} corresponding to resource C is not transmitted, and can receive by assuming that symbol sequence {Symbol #1, Symbol #2, Symbol #4} corresponding to the remaining resources {Resource #1, Resource #2, Resource #4}—excluding {Resource #3} corresponding to resource C—is mapped and transmitted. Consequently, the terminal can perform a subsequent series of receiving operations by assuming that the symbol sequence {Symbol #1, Symbol #2, Symbol #4} has been transmitted and mapped to {Resource #1, Resource #2, Resource #4}, respectively.

[0185] In the following, a method for configuring rate matching resources for the purpose of rate matching in a 5G communication system is described. Rate matching refers to the adjustment of the signal size by considering the amount of resources available to transmit the signal. For example, rate matching of a data channel may mean that the data channel is mapped to a specific time and frequency resource range so that the data size is adjusted accordingly without transmission.

[0186] FIG. 6 is a diagram illustrating a method for transmitting and receiving data by a base station and a terminal in consideration of a downlink data channel and rate matching resources according to one embodiment of the present disclosure.

[0187] FIG. 6 illustrates a downlink data channel (PDSCH, 601) and a rate matching resource (602). A base station may set one or more rate matching resources (602) to a terminal through upper layer signaling (e.g., RRC signaling). The rate matching resource (602) setting information may include time-axis resource allocation information (603), frequency-axis resource allocation information (604), and period information (605). In the following, the bitmap corresponding to the frequency-axis resource allocation information (604) will be named the "first bitmap," the bitmap corresponding to the time-axis resource allocation information (603) will be named the "second bitmap," and the bitmap corresponding to the period information (605) will be named the "third bitmap." If all or part of the time and frequency resources of a scheduled data channel (601) overlap with a set rate matching resource (602), the base station can transmit the data channel (601) by rate matching it in the rate matching resource (602) portion, and the terminal can perform reception and decoding after assuming that the data channel (601) is rate matched in the rate matching resource (602) portion.

[0188] The base station can dynamically notify the terminal via DCI whether to rate match a data channel in the above-mentioned rate matching resource portion through additional settings (corresponding to the "rate matching indicator" within the aforementioned DCI format). Specifically, the base station can select some of the above-mentioned rate matching resources and group them into rate matching resource groups, and can indicate to the terminal via DCI using a bitmap method whether to rate match a data channel for each rate matching resource group. For example, if four rate matching resources, RMR#1, RMR#2, RMR#3, and RMR#4, are set, the base station can set RMG#1={RMR#1, RMR#2} and RMG#2={RMR#3, RMR#4} as rate matching groups, and can indicate to the terminal via a bitmap whether to rate match in RMG#1 and RMG#2, respectively, using 2 bits within the DCI field. For example, you can indicate "1" when rate matching is required and "0" when rate matching is not required.

[0189] In a 5G system, the granularity of "RB symbol level" and "RE level" is supported by setting the aforementioned rate matching resources to a terminal. More specifically, the following setting method may be followed.

[0190] RB symbol level

[0191] The terminal can receive up to four RateMatchPatterns as upper layer signaling for each bandwidth portion, and one RateMatchPattern may include the following contents.

[0192] - As a Reserved Resource within the bandwidth portion, a resource may be included in which the time and frequency resource domains of the said Reserved Resource are set as a combination of an RB level bitmap and a symbol level bitmap along the frequency axis. The said Reserved Resource may span across one or two slots. A time domain pattern (periodicityAndPattern) in which the time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may be additionally set.

[0193] - It may include time and frequency domain resource areas set as control resource sets within the bandwidth portion, and resource areas corresponding to time domain patterns set as search space settings where the resource areas are repeated.

[0194] RE level

[0195] The terminal can receive the following settings through upper-layer signaling.

[0196] - Configuration information for an RE corresponding to an LTE CRS (Cell-specific Reference Signal or Common Reference Signal) pattern (lte-CRS-ToMatchAround) may include the number of ports of the LTE CRS (nrofCRS-Ports) and the LTE-CRS-vshift(s) value (v-shift), the location information of the LTE carrier's center subcarrier (carrierFreqDL) from a reference frequency point (e.g., reference point A), the LTE carrier's bandwidth size (carrierBandwidthDL) information, and subframe configuration information corresponding to a Multiast-broadcast single-frequency network (mbsfn-SubframeConfigList). Based on the aforementioned information, the terminal can determine the location of the CRS within an NR slot corresponding to an LTE subframe.

[0197] - It may include configuration information for resource sets corresponding to one or more ZP (Zero Power) CSI-RS within the bandwidth portion.

[0198] [Regarding LTE CRS rate match]

[0199] Next, the rate match process for the LTE CRS described above will be explained in detail. For the coexistence of LTE (Long Term Evolution) and NR (New RAT) (LTE-NR Coexistence), NR provides a function to set the pattern of the LTE CRS (Cell Specific Reference Signal) to the NR terminal. More specifically, the CRS pattern may be provided by RRC signaling that includes at least one parameter within the ServingCellConfig IE (Information Element) or ServingCellConfigCommon IE. Examples of the above parameters may include lte-CRS-ToMatchAround, lte-CRS-PatternList1-r16, lte-CRS-PatternList2-r16, crs-RateMatch-PerCORESETPoolIndex-r16, etc.

[0200] In Rel-15 NR, the lte-CRS-ToMatchAround parameter provides the ability to set one CRS pattern per serving cell. In Rel-16 NR, this ability has been extended to allow multiple CRS patterns to be set per serving cell. More specifically, for a Single-TRP (transmission and reception point) configured terminal, one CRS pattern can be set per LTE carrier, and for a Multi-TRP configured terminal, two CRS patterns can be set per LTE carrier. For example, for a Single-TRP configured terminal, up to three CRS patterns per serving cell can be set through the lte-CRS-PatternList1-r16 parameter. As another example, for a multi-TRP configured terminal, CRS can be set per TRP. In other words, the CRS pattern for TRP1 is set via the lte-CRS-PatternList1-r16 parameter, and the CRS pattern for TRP2 can be set via the lte-CRS-PatternList2-r16 parameter. Meanwhile, when two TRPs are configured as described above, whether to apply both TRP1 and TRP2's CRS patterns to a specific PDSCH (Physical Downlink Shared Channel) or only one TRP's CRS pattern is determined by the crs-RateMatch-PerCORESETPoolIndex-r16 parameter; if the crs-RateMatch-PerCORESETPoolIndex-r16 parameter is set to enabled, only one TRP's CRS pattern is applied, whereas otherwise, both TRP's CRS patterns are applied.

[0201] Table 15 shows a ServingCellConfig IE including the above CRS pattern, and Table 16 shows a RateMatchPatternLTE-CRS IE including at least one parameter for the CRS pattern.

[0202]

[0203]

[0204]

[0205] [PDSCH: Regarding Frequency Resource Allocation]

[0206] FIG. 7 is a diagram illustrating an example of frequency axis resource allocation of a PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0207] FIG. 7 is a diagram illustrating three frequency axis resource allocation methods that can be configured through the upper layer in an NR wireless communication system: type 0 (700), type 1 (705), and dynamic switch (710).

[0208] Referring to FIG. 7, if the terminal is configured to use only resource type 0 through upper layer signaling (700), some downlink control information (DCI) that assigns PDSCH to the terminal includes a bitmap consisting of NRBG bits. The conditions for this will be explained later. In this case, NRBG refers to the number of RBGs (resource block groups) determined as shown in [Table 17] below according to the BWP size assigned by the BWP indicator and the upper layer parameter rbg-Size, and data is transmitted to the RBG indicated as 1 by the bitmap.

[0209]

[0210] If the terminal is configured to use only resource type 1 through upper layer signaling (705), some DCIs that assign PDSCH to the terminal are It includes frequency axis resource allocation information consisting of bits. The conditions for this will be explained later. Through this, the base station can set the starting VRB (720) and the length (725) of the frequency axis resources continuously allocated therefrom.

[0211] If the terminal is configured to use both resource type 0 and resource type 1 through upper layer signaling (710), some DCIs that allocate PDSCH to the terminal include frequency axis resource allocation information consisting of bits of the larger value (735) of the payload (715) for setting resource type 0 and the payload (720, 725) for setting resource type 1. The conditions for this will be explained later. At this time, one bit (730) may be added to the first part (MSB) of the frequency axis resource allocation information within the DCI, and if the bit has a value of '0', it indicates that resource type 0 is used, and if it has a value of '1', it indicates that resource type 1 is used.

[0212] [PDSCH / PUSCH: Time Resource Allocation Related]

[0213] The following describes a time-domain resource allocation method for data channels in next-generation mobile communication systems (5G or NR systems).

[0214] The base station may set a table for time-domain resource allocation information for the Physical Downlink Shared Channel (PDSCH) and the Physical Uplink Shared Channel (PUSCH) for the terminal using upper-layer signaling (e.g., RRC signaling). For PDSCH, a table consisting of a maximum of maxNrofDL-Allocations = 16 entries may be set, and for PUSCH, a table consisting of a maximum of maxNrofUL-Allocations = 16 entries may be set. In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted as K0), PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information on the position and length of the start symbol for which the PDSCH or PUSCH is scheduled within the slot, and the mapping type of the PDSCH or PUSCH. For example, information such as [Table 18] or [Table 19] below may be transmitted from the base station to the terminal.

[0215]

[0216]

[0217] The base station may notify the terminal of one of the entries in the table for the time domain resource allocation information described above via L1 signaling (e.g., DCI). For example, it may be indicated by the 'time domain resource allocation' field within the DCI. The terminal may obtain time domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

[0218] FIG. 8 is a diagram illustrating an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0219] Referring to FIG. 8, the base station uses the upper layer to set the subcarrier spacing (SCS) (μ) of the data channel and control channel. PDSCH , μ PDCCH The time axis position of the PDSCH resource can be indicated according to the scheduling offset (K0) value, and the OFDM symbol start position (800) and length (805) within a slot (810) that is dynamically indicated through DCI.

[0220] FIG. 9 is a diagram illustrating an example of time-axis resource allocation according to the subcarrier interval of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

[0221] Referring to FIG. 9, when the subcarrier spacing of the data channel and the control channel is the same (900, μ PDSCH = μ PDCCH), since the slot numbers for data and control are the same, the base station and the terminal can generate a scheduling offset by aligning with a predetermined slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel is different (905, μ PDSCH ≠μ PDCCH Since the slot numbers for data and control are different, the base station and the terminal can generate a scheduling offset based on the subcarrier interval of the PDCCH and in accordance with a predetermined slot offset K0.

[0222] [PUSCH: Regarding transmission method]

[0223] Next, the scheduling method for PUSCH transfers is described. PUSCH transfers can be dynamically scheduled by UL grants within the DCI, or operated by configured grant Type 1 or Type 2. Dynamic scheduling instructions for PUSCH transfers can be provided in DCI format 0_0 or 0_1.

[0224] Configured grant Type 1 PUSCH transmissions can be semi-statically configured by receiving configuredGrantConfig, which includes rrc-ConfiguredUplinkGrant of [Table 20], through the upper signaling, without receiving UL grants within the DCI. Configured grant Type 2 PUSCH transmissions can be semi-continuously scheduled by UL grants within the DCI after receiving configuredGrantConfig, which does not include rrc-ConfiguredUplinkGrant of [Table 20], through the upper signaling. When a PUSCH transmission is operated by a configured grant, the parameters applied to the PUSCH transmission are applied through configuredGrantConfig, the upper signaling of [Table 20], with the exception of dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH, which are provided by pusch-Config, the upper signaling of [Table 21]. If the terminal is provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 20], the terminal applies tp-pi2BPSK in pusch-Config of [Table 21] to PUSCH transmissions operated by the configured grant.

[0225]

[0226] Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission can follow a codebook-based transmission method and a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in pusch-Config in [Table 21], the upper signaling, is 'codebook' or 'nonCodebook'.

[0227] As described above, PUSCH transmissions can be dynamically scheduled via DCI format 0_0 or 0_1 and semi-statically configured by a configured grant. If a terminal is instructed to schedule a PUSCH transmission via DCI format 0_0, the terminal performs beam configuration for the PUSCH transmission using the pucch-spatialRelationInfoID corresponding to the terminal-specific PUCCH resource corresponding to the minimum ID within the active uplink BWP in the serving cell, wherein the PUSCH transmission is based on a single antenna port. The terminal does not expect scheduling for a PUSCH transmission via DCI format 0_0 within a BWP where the PUCCH resource containing pucch-spatialRelationInfo is not configured. If the terminal has not been configured with txConfig in pusch-Config of [Table 21], the terminal does not expect to be scheduled via DCI format 0_1.

[0228]

[0229] Next, codebook-based PUSCH transmission is described. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1 and can operate semi-statically via a configured grant. When codebook-based PUSCH is dynamically scheduled via DCI format 0_1 ​​or semi-statically configured via a configured grant, the terminal determines a precoder for PUSCH transmission based on the SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and the transmission rank (number of PUSCH transmission layers).

[0230] In this case, the SRI can be provided via the SRS resource indicator field within the DCI or configured via the higher-level signaling srs-ResourceIndicator. During codebook-based PUSCH transmission, the terminal receives at least one SRS resource and can receive up to two. When the terminal receives an SRI via the DCI, the SRS resource indicated by that SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH containing that SRI. Additionally, the TPMI and transmission rank can be provided via the precoding information and number of layers field within the DCI or configured via the higher-level signaling precodingAndNumberOfLayers. The TPMI is used to indicate the precoder applied to the PUSCH transmission. If the terminal receives one SRS resource, the TPMI is used to indicate the precoder to be applied from that one configured SRS resource. If the terminal is configured with multiple SRS resources, TPMI is used to specify the precoder to be applied to the SRS resource indicated by SRI.

[0231] The precoder to be used for PUSCH transmission is selected from an uplink codebook having the same number of antenna ports as the nrofSRS-Ports value in the upper signaling SRS-Config. In codebook-based PUSCH transmission, the terminal determines the codebook subset based on TPMI and the codebookSubset in the upper signaling pusch-Config. The codebookSubset in the upper signaling pusch-Config can be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the terminal to the base station. If the terminal reports 'partialAndNonCoherent' as the UE capability, the terminal does not expect the value of the upper signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent'. Additionally, if the terminal reports 'nonCoherent' as a UE capability, the terminal does not expect the value of the parent signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in the parent signaling SRS-ResourceSet points to two SRS antenna ports, the terminal does not expect the value of the parent signaling codebookSubset to be set to 'partialAndNonCoherent'.

[0232] A terminal may receive one SRS resource set in which the value of usage in the upper signaling SRS-ResourceSet is set to 'codebook', and one SRS resource within that SRS resource set may be indicated via SRI. If multiple SRS resources are set in the SRS resource set in which the value of usage in the upper signaling SRS-ResourceSet is set to 'codebook', the terminal expects that the value of nrofSRS-Ports in the upper signaling SRS-Resource will be set to the same value for all SRS resources.

[0233] The terminal transmits one or more SRS resources included in an SRS resource set in which the usage value is set to 'codebook' according to the upper signaling to the base station, and the base station selects one of the SRS resources transmitted by the terminal and instructs the terminal to perform PUSCH transmission using the transmit beam information of the corresponding SRS resource. In this case, in codebook-based PUSCH transmission, SRI is used as information to select the index of one SRS resource and is included in the DCI. Additionally, the base station includes information in the DCI that instructs the TPMI and rank to be used by the terminal for PUSCH transmission. The terminal performs PUSCH transmission using the SRS resource instructed by the SRI, by applying the instructed rank and the precoder instructed by the TPMI based on the transmit beam of the corresponding SRS resource.

[0234] Next, non-codebook-based PUSCH transmission is described. Non-codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1 and can operate semi-statically via configured grant. If at least one SRS resource is configured within an SRS resource set in which the value of usage within the upper signaling SRS-ResourceSet is set to 'nonCodebook', the terminal can receive a non-codebook-based PUSCH transmission via DCI format 0_1.

[0235] For an SRS resource set in which the value of usage within the upper signaling SRS-ResourceSet is set to 'nonCodebook', the terminal can receive one connected NZP CSI-RS resource (non-zero power CSI-RS). The terminal can perform calculations for a precoder for SRS transmission by measuring the NZP CSI-RS resource connected to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource connected to the SRS resource set and the first symbol of the aperiodic SRS transmission at the terminal is less than 42 symbols, the terminal does not expect the information for the precoder for SRS transmission to be updated.

[0236] If the value of resourceType in the upper signaling SRS-ResourceSet is set to 'aperiodic', the connected NZP CSI-RS is indicated by the SRS request field in DCI format 0_1 ​​or 1_1. In this case, if the connected NZP CSI-RS resource is a non-periodic NZP CSI-RS resource, the existence of the connected NZP CSI-RS is indicated if the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not '00'. In this case, the corresponding DCI must not indicate cross-carrier or cross-BWP scheduling. Additionally, if the value of the SRS request indicates the existence of the NZP CSI-RS, the NZP CSI-RS is located in the slot where the PDCCH containing the SRS request field was transmitted. In this case, the TCI states set on the scheduled subcarrier are not set to QCL-TypeD.

[0237] If a periodic or semi-persistent SRS resource set is established, the associated NZP CSI-RS can be indicated via the associated CSI-RS within the parent signaling SRS-ResourceSet. For non-codebook-based transmissions, the terminal does not expect the parent signaling spatialRelationInfo for the SRS resource and the associated CSI-RS within the parent signaling SRS-ResourceSet to be established together.

[0238] When a terminal is configured with multiple SRS resources, it can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. In this case, the SRI can be indicated via the field SRS resource indicator within the DCI or configured via the higher-level signaling srs-ResourceIndicator. Similar to the codebook-based PUSCH transmission described above, when the terminal receives the SRI via the DCI, the SRS resource indicated by the SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH containing the SRI. The terminal may use one or multiple SRS resources for SRS transmission, and the maximum number of SRS resources that can be transmitted simultaneously within the same symbol in a single SRS resource set, as well as the maximum number of SRS resources, are determined by the UE capability reported by the terminal to the base station. In this case, the SRS resources transmitted simultaneously by the terminal occupy the same RB. The terminal configures one SRS port for each SRS resource. Only one SRS resource set can be configured with the usage value in the upper signaling SRS-ResourceSet set set to 'nonCodebook', and up to four SRS resources can be configured for non-codebook-based PUSCH transmission.

[0239] The base station transmits one NZP-CSI-RS associated with an SRS resource set to the terminal, and the terminal calculates a precoder to be used when transmitting one or more SRS resources within the SRS resource set based on the results measured upon receiving the NZP-CSI-RS. When the terminal transmits one or more SRS resources within an SRS resource set where usage is set to 'nonCodebook' to the base station, it applies the calculated precoder, and the base station selects one or more SRS resources from the received one or more SRS resources. At this time, in non-codebook-based PUSCH transmission, the SRI represents an index capable of expressing a combination of one or more SRS resources, and the SRI is included within the DCI. At this time, the number of SRS resources indicated by the SRI transmitted by the base station may be the number of transmission layers of the PUSCH, and the terminal transmits the PUSCH by applying the precoder applied for SRS resource transmission to each layer.

[0240] [PUSCH: Preparation Process Time]

[0241] Next, the PUSCH preparation procedure time is described. When a base station schedules a terminal to transmit a PUSCH using DCI format 0_0, 0_1, or 0_2, the terminal may require PUSCH preparation procedure time to transmit the PUSCH by applying the transmission method specified through the DCI (transmission precoding method of the SRS resource, number of transmission layers, spatial domain transmission filter). In NR, the PUSCH preparation procedure time has been defined taking this into account. The terminal's PUSCH preparation procedure time may follow [Equation 2] below.

[0242] [Mathematical Formula 2]

[0243]

[0244] The aforementioned T in mathematical formula 2 proc,2 In this, each variable can have the following meanings.

[0245] - N2: A number of symbols determined by the terminal processing capability (UE processing capability) 1 or 2 and the numerology μ according to the terminal's capability. If the terminal processing capability is reported as 1 according to the terminal's capability report, it has the value of [Table 22], and if the terminal processing capability is reported as 2 and the ability to use terminal processing capability 2 is set through upper layer signaling, it may have the value of [Table 23].

[0246]

[0247]

[0248] - d 2,1 : The number of symbols determined as 0 if the resource elements of the first OFDM symbol of the PUSCH transmission are all configured to consist only of DM-RS, and 1 otherwise.

[0249] - κ: 64

[0250] - μ: μ DL or μ UL Middle, T proc,2 It follows the value that becomes larger. μ DL represents the numerology of the downlink through which a PDCCH containing a DCI scheduling PUSCH is transmitted, and μ UL represents the numerology of the uplink through which PUSCH is transmitted.

[0251] - T c : 1 / (Δf max *N f ), Δf max = 480*10 3 Hz, N f It has =4096.

[0252] - d 2,2 : If the DCI scheduling PUSCH directs BWP switching, follow the BWP switching time; otherwise, have 0.

[0253] - d2: If the OFDM symbols of PUCCH, PUSCH with a higher priority index, and PUCCH with a lower priority index overlap in time, the d2 value of PUSCH with the higher priority index is used. Otherwise, d2 is 0.

[0254] - T ext : If the terminal uses a shared spectrum channel access method, the terminal is T ext It can be calculated and applied to the PUSCH preparation process time. Otherwise, T ext is assumed to be 0.

[0255] - T switch : T when the uplink switching interval is triggered switch is assumed to be the switching interval time. Otherwise, it is assumed to be 0.

[0256] When the base station and terminal consider the time-axis resource mapping information of the PUSCH scheduled via DCI and the influence of uplink-downlink timing advance, from the last symbol of the PDCCH including the DCI that scheduled the PUSCH, T proc,2 Subsequently, if the first symbol of the PUSCH starts before the first uplink symbol initiated by the CP, it is determined that the PUSCH preparation time is insufficient. Otherwise, the base station and the terminal determine that the PUSCH preparation time is sufficient. The terminal transmits the PUSCH only when the preparation time is sufficient, and may ignore the DCI scheduling the PUSCH if the preparation time is insufficient.

[0257] [CA / DC Related]

[0258] FIG. 10 is a diagram illustrating the wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, or dual connectivity situation according to one embodiment of the present disclosure.

[0259] Referring to FIG. 10, the wireless protocol of the next-generation mobile communication system consists of NR SDAP (Service Data Adaptation Protocol 1025, 1070), NR PDCP (Packet Data Convergence Protocol 1030, 1065), NR RLC (Radio Link Control 1035, 1060), and NR MAC (Medium Access Control 1040, 1055) at the terminal and the NR base station, respectively.

[0260] The main functions of NR SDAP (1025, 1070) may include some of the following functions.

[0261] - User data transfer function (transfer of user plane data)

[0262] - Mapping function between a QoS flow and a DRB for both DL and UL for uplink and downlink

[0263] - Marking QoS flow ID for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0264] - Function to map reflective QoS flow to data bearers for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0265] Regarding the above SDAP layer device, the terminal may receive a setting via an RRC message indicating whether to use the header of the SDAP layer device or the functions of the SDAP layer device for each PDCP layer device, bearer, or logical channel. If the SDAP header is configured, the terminal may be instructed to update or reset the mapping information for the uplink and downlink QoS flows and data bearers to the NAS reflective QoS and AS reflective QoS 1-bit indicators of the SDAP header. The above SDAP header may include QoS flow ID information indicating QoS. The above QoS information may be used for data processing priority, scheduling information, etc., to support smooth service.

[0266] The main functions of NR PDCP (1030, 1065) may include some of the following functions.

[0267] - Header compression and decompression features (ROHC only)

[0268] - User data transfer function (Transfer of user data)

[0269] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0270] - Out-of-sequence delivery of upper layer PDUs

[0271] - Reordering function (PDCP PDU reordering for reception)

[0272] - Duplicate detection function (Duplicate detection of lower layer SDUs)

[0273] - Retransmission of PDCP SDUs

[0274] - Encryption and decryption functions (Ciphering and deciphering)

[0275] - Timer-based SDU discard in uplink.

[0276] In the above, the reordering function of the NR PDCP device refers to a function that reorders PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function that transmits data to an upper layer in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function that transmits immediately without considering the order, a function that records lost PDCP PDUs by reordering, a function that reports the status of lost PDCP PDUs to the transmitting side, and a function that requests retransmission of lost PDCP PDUs.

[0277] The main functions of NR RLC(1035, 1060) may include some of the following functions.

[0278] - Data transfer function (Transfer of upper layer PDUs)

[0279] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0280] - Out-of-sequence delivery of upper layer PDUs

[0281] - ARQ function (Error Correction through ARQ)

[0282] - Concatenation, segmentation, and reassembly functions of RLC SDUs

[0283] - Re-segmentation function (Re-segmentation of RLC data PDUs)

[0284] - Reordering function (Reordering of RLC data PDUs)

[0285] - Duplicate detection

[0286] - Error detection function (Protocol error detection)

[0287] - RLC SDU discard function

[0288] RLC re-establishment function

[0289] In the above, the in-sequence delivery function of the NR RLC device refers to the function of delivering RLC SDUs received from a lower layer to an upper layer in order. The in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering the RLC SDUs when the original RLC SDU is received divided into multiple RLC SDUs, a function of rearranging the received RLC PDUs based on an RLC SN (sequence number) or PDCP SN (sequence number), a function of recording lost RLC PDUs by rearranging the order, a function of reporting the status of lost RLC PDUs to the transmitting side, and a function of requesting retransmission of lost RLC PDUs. The in-sequence delivery function of the NR RLC device may include a function to deliver only the RLC SDUs prior to the lost RLC SDU in order to the upper layer if there is a lost RLC SDU, or a function to deliver all RLC SDUs received before the timer started in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU. Alternatively, the in-sequence delivery function of the NR RLC device may include a function to deliver all RLC SDUs received up to the present in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU.In addition, the RLC PDUs described above may be processed in the order they are received (regardless of the order of sequence numbers, in the order of arrival) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, segments stored in a buffer or to be received later may be received, reconstructed into a single complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and this function may be performed by the NR MAC layer or replaced by the multiplexing function of the NR MAC layer.

[0290] In the above, the out-of-sequence delivery function of the NR RLC device refers to the function of delivering RLC SDUs received from a lower layer directly to an upper layer regardless of order. It may include a function of reassembling and delivering RLC SDUs when a single RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing the RLC SN or PDCP SN of the received RLC PDUs and sorting the order to record the lost RLC PDUs.

[0291] The NR MAC (1040, 1055) can be connected to multiple NR RLC layer devices configured in a terminal, and the main functions of the NR MAC may include some of the following functions.

[0292] - Mapping function (Mapping between logical channels and transport channels)

[0293] - Multiplexing and demultiplexing functions (Multiplexing / demultiplexing of MAC SDUs)

[0294] - Scheduling information reporting function

[0295] - HARQ function (Error correction through HARQ)

[0296] - Priority handling between logical channels of one UE

[0297] - Priority handling between UEs by means of dynamic scheduling

[0298] - MBMS service identification function

[0299] - Transport format selection function

[0300] - Padding

[0301] The NR PHY layer (1045, 1050) can perform the operation of channel coding and modulating upper layer data, creating OFDM symbols and transmitting them to the wireless channel, or demodulating OFDM symbols received through the wireless channel and channel decoding them to transmit them to the upper layer.

[0302] The detailed structure of the above wireless protocol structure may vary depending on the carrier (or cell) operation method. For example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure that has a single structure for each layer, such as 1000. On the other hand, when a base station transmits data to a terminal based on Carrier Aggregation (CA) using multiple carriers in a single TRP, the base station and the terminal use a protocol structure that has a single structure up to the RLC, such as 1010, but multiplexes the PHY layer through the MAC layer. As another example, when a base station transmits data to a terminal based on Dual Connectivity (DC) using multiple carriers in multiple TRPs, the base station and the terminal use a protocol structure that has a single structure up to the RLC, such as 1020, but multiplexes the PHY layer through the MAC layer.

[0303] Referring to the descriptions regarding PDCCH and beam settings mentioned above, PDCCH repeated transmission is not supported in current Rel-15 and Rel-16 NR, making it difficult to achieve the required reliability in scenarios requiring high reliability, such as URLLC. The present invention provides a method for PDCCH repeated transmission through multiple transmission points (TRPs) to improve the PDCCH reception reliability of a terminal. The specific method is described in detail in the following examples.

[0304] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The contents of the present disclosure are applicable to FDD and TDD systems. In the present disclosure, upper signaling (or upper layer signaling) is a signal transmission method transmitted from a base station to a terminal using a physical layer downlink data channel, or from a terminal to a base station using a physical layer uplink data channel, and may be referred to as RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC CE).

[0305] In the present disclosure, when determining whether cooperative communication is applied, the terminal may use various methods, such as the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied having a specific format, or the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied including a specific indicator indicating whether cooperative communication is applied, or the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied being scrambled with a specific RNTI, or assuming the application of cooperative communication in a specific section indicated to an upper layer. For convenience of explanation thereafter, the case in which the terminal receives a PDSCH to which cooperative communication is applied based on conditions similar to those above will be referred to as the NC-JT case.

[0306] In the following disclosure, determining the priority between A and B may be referred to in various ways, such as selecting the one with the higher priority according to a predetermined priority rule and performing the corresponding action, or omitting or dropping the action for the one with the lower priority.

[0307] In the following disclosure, the examples are described through a number of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0308] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, gNB, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. Although embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and mobile communication technologies developed after 5G may be included therein. Accordingly, embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure, as judged by a person skilled in the art. The contents of the present disclosure are applicable to FDD and TDD systems.

[0309] Furthermore, in describing the present disclosure, if it is determined that a detailed description of related functions or configurations could unnecessarily obscure the essence of the present disclosure, such detailed description is omitted. Additionally, the terms described below are defined in consideration of their functions within the present disclosure, and these definitions may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0310] In describing the present disclosure below, the term "upper layer signaling" may refer to a signaling corresponding to at least one or a combination of at least one of the following signalings.

[0311] - MIB (Master Information Block)

[0312] - SIB (System Information Block) or SIB

[0313] - RRC (Radio Resource Control)

[0314] - MAC (Medium Access Control) CE (Control Element)

[0315] In addition, L1 signaling may be a signaling corresponding to at least one or a combination of at least one of the following physical layer channels or signaling methods using signaling.

[0316] - PDCCH (Physical Downlink Control Channel)

[0317] - DCI (Downlink Control Information)

[0318] - Terminal-specific (UE-specific) DCI

[0319] - Group common DCI

[0320] - Common DCI

[0321] - Scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data)

[0322] - Non-scheduling DCI (e.g., DCI not intended for scheduling downlink or uplink data)

[0323] - PUCCH (Physical Uplink Control Channel)

[0324] - UCI (Uplink Control Information)

[0325] In the following disclosure, determining the priority between A and B may be referred to in various ways, such as selecting the one with the higher priority according to a predetermined priority rule and performing the corresponding action, or omitting or dropping the action for the one with the lower priority.

[0326] In the following disclosure, the examples are described through a number of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0327] In the present disclosure, the carrier can be changed to a cell and applied, and the cell can be changed to a carrier. In the present disclosure, among the two cells, the Pcell may be a cell that supports FDD (Frequency Division Duplex), and the Scell ​​may be a cell that supports SDL (Supplementary Downlink).

[0328] [Downlink Carrier Switching]

[0329] FIG. 11 is a drawing illustrating downlink carrier switching (DL carrier switching) according to one embodiment of the present disclosure.

[0330] Referring to FIG. 11, a terminal may receive a plurality of cells or a plurality of carriers from a base station. Here, the plurality of cells or a plurality of carriers may include resources capable of receiving a downlink. Here, the plurality of cells or a plurality of carriers may be of different frequencies. Here, the plurality of cells or a plurality of carriers may be configured by a carrier aggregation method. The terminal may receive a downlink channel or a downlink signal from the plurality of cells or a plurality of carriers.

[0331] Generally, a terminal may have separate RF (radio frequency) signal receivers to receive multiple cells or multiple carriers of different frequencies. However, for a specific frequency band, only one RF signal receiver may be provided due to propagation characteristics, terminal area, and terminal cost. In this case, the terminal must receive multiple cells or multiple carriers through a single RF signal receiver. As a method for receiving multiple cells or multiple carriers through a single RF signal receiver, one of the multiple cells or multiple carriers may be received by changing the center frequency and bandwidth of the terminal's RF signal receiver. This may be called DL carrier switching. Referring to FIG. 11, in the first time interval (1100) and the third time interval (1120), the RF signal receiver is configured to match the center frequency and bandwidth of Cell B, so that the downlink channel and / or signal of Cell B can be received. In the second time interval (1110) to the fourth time interval (1130), a receiver of the RF signal is configured to match the center frequency and bandwidth of Cell A, so that it can receive the downlink channel and / or signal of Cell A.

[0332] When a terminal changes the center frequency and bandwidth of the RF signal receiver, the terminal may require a certain amount of time. This time may vary depending on the type of terminal. Accordingly, the terminal may transmit this time to the base station via a UE capability report. During this time, the terminal may not be able to receive the downlink channel or signal.

[0333] The terminal can receive the length of the time interval (ms or the number of slots), the repetition period, and the index of the cell (or carrier index) to be received for each time interval from the base station via an upper layer signal (e.g., an RRC signal). For example, if the time interval is X slots and the repetition period is Y = P * X slots, the terminal can receive a bitmap of length Y / X = P bits from the base station. Each bit of the bitmap may correspond to X slots included in the Y = P * X slots. Furthermore, the value indicated by the bitmap may be applied repeatedly according to the repetition period.

[0334] Here, a single bitmap can be applied commonly to multiple cells. For example, for two cells, the terminal can determine which of the two cells is used for downlink reception at each time interval through a single bitmap. If a specific bit of the bitmap is a first value (e.g., '0'), the terminal can receive a downlink from the first cell in X slots corresponding to that bit. If a specific bit of the bitmap is a second value (e.g., '1'), the terminal can receive a downlink from the second cell in X slots corresponding to that bit.

[0335] Here, one bitmap can be applied to one cell. That is, through one bitmap, the terminal can determine whether one cell can be used for downlink reception at each time interval. For example, two bitmaps can be set for two cells. The two bitmaps may include a first bitmap and a second bitmap. Here, the first bitmap can indicate whether the first cell receives a downlink, and the second bitmap can indicate whether the second cell receives a downlink. If a specific bit of the first bitmap is a first value (e.g., '0'), the terminal cannot receive a downlink from the first cell in X slots corresponding to that bit. If a specific bit of the first bitmap is a second value (e.g., '1'), the terminal can receive a downlink from the first cell in X slots corresponding to that bit. If a specific bit of the second bitmap is a first value (e.g., '0'), the terminal cannot receive a downlink from the second cell in X slots corresponding to that bit. If a specific bit of the second bitmap is a second value (e.g., '1'), the terminal can receive a downlink from the second cell in X slots corresponding to that bit.

[0336] For reference, if the terminal is instructed to receive a downlink from two cells (i.e., the same bit in the first bitmap and the second bitmap is instructed as '1'), the terminal may determine that it is an incorrect instruction. That is, the terminal may not apply the bitmap.

[0337] Alternatively, if the terminal is instructed to receive a downlink from two cells (i.e., the same bit in the first bitmap and the second bitmap is indicated as '1'), the terminal may receive the downlink by prioritizing one of the two cells. For example, the terminal may receive the downlink from the cell with the lower index of the two cells. Here, the cell index is merely an example for determining priority, and as another example, the terminal may receive the downlink from the Pcell of the two cells. As yet another example, the terminal may receive the downlink from the cell of the two cells that is configured to monitor the PDCCH.

[0338] In the example described above, the cell to receive the downlink is configured based on a bitmap, but the cell to receive the downlink may also be configured via other signals. For example, for a cell, a terminal may be configured with a period (ms or the number of slots) and a starting index to an ending index of symbols for receiving the downlink within the period. For the cell, the terminal may receive the downlink within the period from the symbol corresponding to the starting index to the symbol corresponding to the ending index. The terminal may receive the downlink of another cell from the remaining symbols excluding the symbols mentioned above.

[0339] For example, for a cell, a terminal may be configured with a period (ms or the number of slots) and a starting index to an ending index of slots for receiving downlinks within the period. For said cell, the terminal may receive downlinks within the period from the slot corresponding to the starting index to the slot corresponding to the ending index. The terminal may receive downlinks from another cell in the remaining slots excluding said slots.

[0340] For example, for a cell, a terminal may be configured with a period (ms or the number of slots) and a starting slot index for receiving downlinks within the period, an index of the starting symbol within the starting slot to an index of the last slot, and an index of the last symbol within the last slot. For the cell, the terminal may receive downlinks within the period from the symbol corresponding to the starting symbol index of the slot corresponding to the starting slot index to the symbol corresponding to the last symbol index of the slot corresponding to the last slot index. The terminal may receive downlinks from another cell at the remaining symbols excluding the symbols.

[0341] The terminal can apply the period starting from the first symbol of the frame. Alternatively, the terminal can apply the period starting from a specific time after the frame. Here, the specific time can be set by the base station.

[0342] According to the upper layer settings for DL ​​carrier switching, the terminal may receive a downlink from only one of the two cells during a time interval. For example, during the first time interval, the terminal may receive a downlink from the second cell (cell B). However, during the first time interval, a signal that the terminal must receive (e.g., SSB, TRS (tracking reference signal, or PDCCH for scheduling system information, or at least one of PDSCH containing system information)) may be set in the first cell (cell B). In this case, the terminal may prioritize the reception of the signal it must receive over the upper layer settings for DL ​​carrier switching.

[0343] For example, if an SSB is set in the first cell (cell A) during the first time interval, the terminal can receive downlinks from symbols where the SSB is set in the first cell (cell A).

[0344] In the example described above, the terminal must frequently perform DL carrier switching to receive a signal that must be received. In this case, power consumption and DL carrier switching time are required for changing the RF receiver of the terminal. Therefore, a method for limiting frequent DL carrier switching is disclosed.

[0345] The terminal can continue to receive the downlink of a cell without changing the DL carrier switching during a specific time interval corresponding to the signal that must be received.

[0346] Here, the signal that must be received may be an SSB. Here, a specific time interval may be a slot in which an SSB is set. In this case, if an SSB is set in the first cell (Cell A) during the first time interval, the terminal can receive a downlink from all symbols in the slot in which the SSB is set in the first cell (Cell A). That is, for symbols included in the same slot as the SSB, the terminal can receive a downlink even if the SSB is not received for the symbol.

[0347] Here, the signal that must be received may be an SSB. Here, a specific time interval may be a half frame in which an SSB is set. In this case, if an SSB is set in the first cell (Cell A) during the first time interval, the terminal can receive a downlink from all symbols in the half frame in which the SSB is set in the first cell (Cell A). That is, for symbols included in the same half frame as the SSB, the terminal can receive a downlink even if the SSB is not received for a symbol.

[0348] Here, the signal that must be received may be an SSB. Here, a specific time interval may be from the first symbol to the last symbol of the SSBs for multiple SSBs set within a half frame. In this case, if an SSB is set in the first cell (Cell A) during the first time interval, the terminal can receive the downlink from the first symbol to the last symbol of the SSB in the half frame where the SSB is set in the first cell (Cell A). That is, for the symbols included between the starting symbol and the last symbol of the SSB among the multiple SSBs set within the half frame, the terminal can receive the downlink even if the SSB is not received.

[0349] The signal that must be received here may be an SSB. Here, a specific time interval may be from the first slot to the last slot of the SSB for multiple SSBs set within a half frame. In this case, if an SSB is set in the first cell (Cell A) during the first time interval, the terminal can receive the downlink from the first slot to the last slot of the SSB in the half frame where the SSB is set in the first cell (Cell A). That is, for symbols included between the first slot and the last slot of the SSB among multiple SSBs set within the half frame, the terminal can receive the downlink even if the symbol is not an SSB.

[0350] The SSB described above as a signal that must be received is merely an example and does not limit the scope of the present invention. For example, the signal that the terminal must receive may be any signal other than the SSB, and in this case, the content described above regarding the SSB may be applied in the same way to any other signal. The terminal may require a transient period for changing the receiver of the RF signal. Here, the transient period may be determined based on a value reported as the terminal's capability. That is, the terminal may determine the symbols corresponding to the transient period based on the value reported as the terminal's capability. Alternatively, the number of symbols corresponding to the transient period may be set by the base station. The terminal may determine the symbols corresponding to the transient period as invalid symbols.

[0351] Here, the position of the transient period can be as follows.

[0352] For example, a transient period may be applied after the last symbol of the cell prior to DL carrier switching. In this case, a transient period may be applied to the first symbol(s) of the cell after DL carrier switching.

[0353] When changing from the first cell to the second cell, the transient period may be applied after the last symbol of the first cell. That is, the terminal can determine the downlink reception period of the first cell and the downlink reception period of the second cell according to the DL carrier switching settings. The terminal may apply the transient period after the last symbol of the downlink reception period of the first cell. Accordingly, downlink reception may be impossible from the first symbol of the downlink reception period of the second cell to the symbols corresponding to the transient period. When changing from the second cell to the first cell, the transient period may be applied after the last symbol of the second cell. That is, the terminal can determine the downlink reception period of the second cell and the downlink reception period of the first cell according to the DL carrier switching settings. The terminal may apply the transient period after the last symbol of the downlink reception period of the second cell. Accordingly, downlink reception may be impossible from the first symbol of the downlink reception period of the first cell to the symbols corresponding to the transient period.

[0354] For example, a transient period may be applied before the last symbol of the cell prior to DL carrier switching. In this case, a transient period may not be applied to the first symbol(s) of the cell after DL carrier switching.

[0355] When changing from the first cell to the second cell, the transient period may be applied before the last symbol of the first cell. That is, the terminal can determine the downlink reception period of the first cell and the downlink reception period of the second cell according to the DL carrier switching settings. The terminal can apply the transient period before the last symbol of the downlink reception period of the first cell (i.e., in the time interval prior to the boundary between the last symbol and the next symbol). Accordingly, the first symbol of the downlink reception period of the second cell may not be affected by the transient period. When changing from the second cell to the first cell, the transient period may be applied before the last symbol of the second cell. That is, the terminal can determine the downlink reception period of the second cell and the downlink reception period of the first cell according to the DL carrier switching settings. The terminal can apply the transient period before the last symbol of the downlink reception period of the second cell (i.e., in the time interval prior to the boundary between the last symbol and the next symbol). Accordingly, the first symbol of the downlink receiving interval of the first cell may not be affected by the transient period.

[0356] For example, a transient period may be applied to only one cell. In this case, the transient period may not be applied to the other cell. For example, when changing from the first cell to the second cell, a transient period may be applied after the last symbol of the first cell (to the starting symbol of the second cell). When changing from the second cell to the first cell, a transient period may be applied before the last symbol of the second cell. As an example, the cell to which the transient period is not applied may be a Pcell. Alternatively, the cell to which the transient period is not applied may be a cell that supports FDD operations. Alternatively, the cell to which the transient period is not applied may be the cell with the lower index of the two cells.

[0357] [Regarding Type-1 HARQ-ACK Codebook]

[0358] This explains how to configure the Type-1 HARQ-ACK codebook in an NR system. For reference, the Type-1 HARQ-ACK codebook is also called the semi-static HARQ-ACK codebook.

[0359] The following description describes a situation where the number of PUCCHs a terminal can transmit HARQ-ACK information to is limited to one within a single time unit (e.g., slot, sub-slot, mini-slot). Unless otherwise noted, the time unit is described as a slot, but this can be extended to sub-slots, mini-slots, etc.

[0360] In an NR system, a terminal can receive only one PDSCH per symbol. That is, if two or more PDSCHs are scheduled for a single symbol, the terminal can determine that the scheduling is an error. Unless otherwise noted, the existing semi-static HARQ-ACK codebook is described assuming a terminal capable of receiving only one PDSCH per symbol. The new semi-static HARQ-ACK codebook is a codebook for terminals capable of receiving two or more PDSCHs per symbol.

[0361] The terminal may receive existing semi-static HARQ-ACK codebook settings from the base station. Here, the settings may be configured using a higher-layer signal (e.g., an RRC signal). The terminal may receive a DCI format from the base station. The terminal may transmit HARQ-ACK information, ranging from PDSCH to SPS PDSCH release to Scell ​​dormancy indication scheduled by the DCI format, in a slot indicated by the value of the PDSCH-to-HARQ_feedback timing indicator field within the DCI format. If the terminal is instructed to transmit multiple HARQ-ACK information in a single slot, the terminal may generate the HARQ-ACK information into a HARQ-ACK codebook according to a defined rule and transmit it as a single PUCCH in the slot.

[0362] The rules for generating a more specific existing semi-static HARQ-ACK codebook are as follows.

[0363] The terminal reports the HARQ-ACK information bit value in the HARQ-ACK codebook as NACK in slots not indicated by the PDSCH-to-HARQ_feedback timing indicator field in the DCI format.

[0364] If the terminal receives all M candidate PDSCHs A,C When only HARQ-ACK information for one SPS PDSCH release or one PDSCH reception is reported on occasions, and the report is scheduled by DCI format 1_0 containing information in which the counter DAI field in the Pcell indicates 1, the terminal determines one HARQ-ACK codebook for the corresponding SPS PDSCH release or the corresponding PDSCH reception.

[0365] Except for that, the HARQ-ACK codebook determination method according to the method described above is followed.

[0366] For the convenience of the present invention, the PDSCH-to-HARQ_feedback timing indicator value is referred to as the K1 value. A terminal may receive multiple K1 values, and these multiple K1 values ​​are collectively referred to as the K1 set.

[0367] The set of PDSCH reception candidate occasions in serving cell c is M A,c saying, and afterwards M A,c Describe the method for obtaining or calculating.

[0368] First, let's assume that the PDSCH scheduled by the DCI format is received in a single slot. This may include cases where the pdsch-AggregationFactor is not set from the upper layer.

[0369] When transmitting PUCCH or PUSCH that conveys the existing semi-static HARQ-ACK codebook in slot n, the pseudo-code for this is as follows.

[0370] [pseudo-code 1:]

[0371] - Preparation phase: Set R is a set of scheduling information (slot information where PDSCH is mapped (hereinafter K0 value), starting symbol and length information (hereinafter SLIV (starting and length value)) set in the TDRA (time domain resource assignment) table. If the terminal monitors one or more DCI formats and the DCI formats use different TDRA tables, the set R is generated based on all TDRA tables.

[0372] - Step 0: M A,c Initialize to the empty set. Initialize k to 0. Initialize j to 0.

[0373] - Step 1: Select the k-th largest K1 value from the established set of K1. (For example, if k=0, select the largest K1 value from the set of K1, and if k=1, select the second largest K1 value from the set of K1.) The above K1 value is K 1,k It is said that

[0374] - Step 2: If, K 1,k Slot corresponding to the value (slot nK 1,k If a symbol corresponding to the start symbol and length information (SLIV) belonging to each row of set R overlaps with a symbol set as an uplink in the upper layer, said row may be excluded from set R.

[0375] - Step 3-1 (When the terminal has only the terminal capability (UE capability) to receive at most one unicast PDSCH in a slot): If the determined set R above is not an empty set, then set M A,c Add j as a new PDSCH reception candidate opportunity. When one of the PDSCH candidates in set R is received, the terminal may place the HARQ-ACK of the PDSCH that can be received in the slot at the new PDSCH candidate opportunity j. Increment j by 1.

[0376] - Step 3-2 (If the terminal has the capability to receive more than one unicast PDSCH in a single slot) Set M for the earliest ending SLIV in the determined set R and the SLIVs that overlap with that SLIV in time A,c j is added as a new PDSCH reception candidate opportunity. When one of the PDSCH candidates with the above SLIV is received, the terminal can place the HARQ-ACK of the PDSCH scheduled for one of the SLIVs at the new PDSCH candidate opportunity j. That is, if the index of the above SLIV is r, then b r,k =j may be true. Increment j by 1. Exclude the above SLIVs from set R. Step 3-2 is repeated until set R is empty.

[0377] - Step 4: Increase k by 1. If k is less than the cardinality of the set K1, start again from Step 2, and if k is equal to or greater than the cardinality of the set K1, pseudo-code 1 terminates.

[0378] FIGS. 12a, 12b, and 12c illustrate examples of existing semi-static HARQ-ACK codebooks for HARQ-ACK transmission of PDSCH according to one embodiment of the present disclosure.

[0379] Referring to FIGS. 12a, 12b, and 12c, the terminal performs a PUCCH transmission including HARQ-ACK information in slot n. The HARQ-ACK information may be generated in the form of an existing semi-static HARQ-ACK codebook.

[0380] The terminal can receive uplink / downlink configuration information from the base station. Based on the uplink / downlink configuration information, the terminal can determine whether a symbol is an uplink symbol, a downlink symbol, or a flexible symbol. For convenience, only uplink symbols are described here, and symbols that are not uplink symbols may be downlink symbols or flexible symbols. Referring to FIG. 12a, all symbols in slot n and slot n-1 can be set as uplink symbols. And the last two symbols in slot n-2 can be set as uplink symbols.

[0381] It is assumed that the terminal has K1=2 and K1=3 set as K1 values. That is, the set of K1 is {2,3}. Additionally, the TDRA table in DCI format monitored by the terminal may contain 5 rows as shown in Table 24. For reference, each row may have a K0 value, a SLIV value, or a PDSCH mapping type value set, but for the convenience of explanation, the PDSCH mapping type has been omitted.

[0382]

[0383] Depending on the preparation phase, the terminal may include each SLIV row of the TDRA table in Table 24 in set R. Table 24 shows the SLIVs corresponding to each row. Based on the K1 value and set R, the terminal [includes] the set M of PDSCH reception candidate opportunities. A,c Can determine. M A,c ... may include integer values ​​of {0, 1, ...}. The existing semi-static HARQ-ACK codebook may include a HARQ-ACK bit corresponding to each integer value. The terminal can determine the K1 value (the K1 value is located at the k-th position in the set of K1) and the SLIV index (r) corresponding to the slot corresponding to the received PDSCH. The terminal determines b corresponding to the received PDSCH. r,kThe value is j (b r,k If =j), then M A,c The HARQ-ACK of the received PDSCH may be included at the HARQ-ACK bit position corresponding to j among the integers included in the set. That is, j=0 (b r,k If ), the HARQ-ACK of PDSCH may be included in the first HARQ-ACK bit of the existing semi-static HARQ-ACK codebook.

[0384] Referring to FIGS. 12a, 12b, and 12c, pseudo code 1 can be interpreted as follows. In the following description, it is assumed that the terminal has the ability to receive more than one unicast PDSCH in one slot.

[0385] - Step 0: M A,c Initialize to the empty set. Initialize k to 0. Initialize j to 0.

[0386] - Step 1: Select the k=0th largest K1 value from the established set of K1s. The above K1 value is K 1,0 =3.

[0387] - Step 2: If, slot nK 1,0 = If the symbol corresponding to the start symbol and length information (SLIV) belonging to each SLIV row of set R in n-3 overlaps with a symbol set as an uplink in the upper layer, said SLIV row may be excluded from set R. Referring to FIG. 12b, if some symbols in slot n-3 are semi-static uplink symbols (semi-static UL symbols) set as the upper layer, said SLIV row containing SLIVs that overlap with said symbols may be excluded from set R. Referring to FIG. 12b, since no semi-static uplink symbols are set in slot n-3, not all SLIV rows may be excluded from set R. Set R may include {1, 2, 3, 4, 5}.

[0388] - Step 3-2 (If the terminal has the capability to receive more than one unicast PDSCH in a single slot):

[0389] For the earliest ending SLIV in the above-determined set R and the SLIVs that overlap with that SLIV in time, set M A,c j=0 is added as a new PDSCH receiver candidate. Here, the earliest ending SLIV is SLIV1 (0,4) in row 1, and the SLIVs overlapping with the above SLIV are SLIV2 (0,7) in row 2 and SLIV5 (0,14) in row 5. Therefore, M A,c Add j=0 to, and when the terminal receives a PDSCH scheduled to SLIV1(0,4) of row 1, SLIV2(0,7) of row 2, or SLIV5(0,14) of row 5 in slot n-3, the HARQ-ACK bit of the said PDSCH is the first (j=0) M in the existing semi-static HARQ-ACK codebook. A,c It can be included in the position corresponding to. j is incremented by 1 so that j=1. The SLIV rows of row 1, row 2, and row 5 are excluded from set R, so R = {3, 4}. Since set R is not an empty set, step 3-2 is repeated.

[0390] For the earliest ending SLIV in the above-determined set R and the SLIVs that overlap with that SLIV in time, set M A,c Add j=1 as a new PDSCH receiver candidate. Here, the earliest ending SLIV is SLIV4 (7,4) in row 4, and the SLIV overlapping with the above SLIV is SLIV3 (7,7) in row 3. Therefore, M A,c Add j=1 to, and when the terminal receives a PDSCH scheduled to SLIV4 (7,4) in row 4 or SLIV3 (7,7) in row 3 in slot n-3, the HARQ-ACK bit of the said PDSCH is the second (j=1) M in the existing semi-static HARQ-ACK codebook.A,c It can be included in the position corresponding to. j is increased by 1 so that j=2. The SLIV of row 3 and row 4 above is excluded from set R, so R becomes an empty set. Therefore, step 3-2 can be terminated.

[0391] - Step 4: Increase k by 1 so that k=1. Since k=1 means the cardinality of the set K1 is 2, use the next K1 value to start again from Step 2. Now K 1,1 =2.

[0392] - Step 2: If, slot nK 1,1 = If a symbol corresponding to the start symbol and length information (SLIV) belonging to each row of set R in n-2 overlaps with a symbol set as an uplink in the upper layer, said row may be excluded from set R. Referring to FIG. 12b, if some symbols in slot n-2 are semi-static uplink symbols (semi-static UL symbols) set as the upper layer, rows containing SLIVs that overlap with said symbols may be excluded from set R. Referring to FIG. 12b, a semi-static uplink symbol is set in slot n-2, and the rows that overlap with said semi-static uplink symbol are rows 3 and 5. Therefore, SLIV rows 3 and SLIV rows 5 may be excluded from set R. Set R may include {1, 2, 4}.

[0393] - Step 3-2 (If the terminal has the capability to receive more than one unicast PDSCH in a single slot):

[0394] For the earliest ending SLIV in the above-determined set R and the SLIVs that overlap with that SLIV in time, set M A,c j=2 is added as a new PDSCH receiver candidate. Here, the earliest ending SLIV is SLIV 1 (0,4) in row 1, and the SLIV overlapping with the above SLIV is SLIV 2 (0,7) in row 2. Therefore, MA,c Add j=2 to, and when the terminal receives a PDSCH scheduled to SLIV 1 (0,4) of row 1 or SLIV 2 (0,7) of row 2 in slot n-3, the HARQ-ACK bit of the said PDSCH is the third (j=2) M in the existing semi-static HARQ-ACK codebook. A,c It can be included in the position corresponding to. j is increased by 1 so that j=3. The SLIVs of row 1 and row 2 above are excluded from set R, so R = {4}. Since set R is not an empty set, step 3-2 is repeated.

[0395] For the earliest ending SLIV in the above-determined set R and the SLIVs that overlap with that SLIV in time, set M A,c Add j=3 as a new PDSCH receiver candidate. Here, the leading SLIV is SLIV 4 (7,4) in row 4, and there are no SLIVs that overlap with the above SLIV. Therefore, M A,c Add j=3 to, and when the terminal receives a PDSCH scheduled for SLIV 4(7,4) of row 4 in slot n-3, the HARQ-ACK bit of the said PDSCH is the fourth (j=3) M in the existing semi-static HARQ-ACK codebook. A,c It can be included in the position corresponding to. Increase j by 1 so that j=4. The SLIV of row 4 above is excluded from set R, so R becomes an empty set. Therefore, step 3-2 can be terminated.

[0396] - Step 4: Increase k by 1 so that k=2. Since k=1 is the size (cardinality) of the set K1, the pseudo-code terminates.

[0397] Referring to FIG. 12c, the terminal has M corresponding to four PDSCH reception candidate opportunities j=0, j=1, j=2, and j=3. A,c It can be determined. Here, M corresponding to j=0 and j=1 A,Care PDSCH receive candidate opportunities for slot n-3, and M corresponding to j=2 and j=3 A,C These are the PDSCH receive candidate opportunities of slot n-2. The size of the existing semi-static HARQ-ACK codebook can be determined by the number of PDSCH receive candidate opportunities. The actual number of bits per PDSCH receive candidate opportunity can be determined by the number of transport blocks included in each PDSCH, the number of code block groups (CBGs) included in each PDSCH, or spatial bundling settings.

[0398] FIG. 13 is a simplified diagram illustrating the design flowchart of a conventional semi-static HARQ-ACK codebook according to the present disclosure.

[0399] The flowchart illustrated in FIG. 13 is for a single cell. If multiple cells are configured for the terminal, the flowchart in FIG. 13 can be executed for each cell. In the flowchart illustrated in FIG. 13, the cell index is assumed to be c for explanation.

[0400] FIG. 13 is a flowchart for the case where the terminal has the ability to receive two or more PDSCHs in a slot.

[0401] The set of K1 may contain multiple K1 values. A semi-static HARQ-ACK codebook may be generated in descending order starting from the largest value among the values ​​included in the set of K1. The first K1 value is the highest K1 value, and the index corresponding to said value may be k=0. The second K1 value is the second highest K1 value, and the index corresponding to said value may be k.

[0402] Referring to FIG. 13, the R set may include SLIVs set in the TDRA table. And j=0 and M A,c = It can be set to.

[0403] Referring to Fig. 13, the terminal can continue to perform the following process until the set R becomes an empty set.

[0404] In the first process, the terminal can find the SLIV x with the lowest index of the last symbol among the SLIVs included in the set R.

[0405] In the second process, the terminal can find SLIVs included in the set R that overlap with SLIV x in at least one symbol. If the index of the SLIV is r, b c,k=0,r It can be set to =j. Also, r can be excluded from the set R. If multiple SLIVs overlap with SLIV x, the above process can be performed for the multiple SLIVs. That is, if the indices of the multiple SLIVs are r1 and r2, b c,k=0,r1 =j, b c,k=0,r2 It can be set to =j. Also, r1 and r2 can be excluded from set R. For reference, since SLIV x always overlaps with SLIV x, b x It is set to =j, and x can be excluded from set R.

[0406] In the third process, the terminal is set M A,c You can add j to set M A,c If j is added to, the terminal may include the HARQ-ACK bit corresponding to said j in the existing semi-static HARQ-ACK codebook. The PDSCH corresponding to the HARQ-ACK bit corresponding to said j is b c,k,,r It is a PDSCH scheduled with SLIV r satisfying =j. And, j can be updated to j+1.

[0407] The terminal can perform the first to third processes for the following K1 values.

[0408] If the terminal performs the first to third processes for all K1 values, the terminal may stop generating the HARQ-ACK codebook for cell c.

[0409] M A,c can contain values ​​{0, 1, 2,...J-1}, where J is M A,c This can be equal to the number of included digits. The size of the HARQ-ACK codebook of cell c can be proportional to J. For a single value of j (j=0,1,...,J-1), B bits of HARQ-ACK can be corresponded. Therefore, the size of the HARQ-ACK codebook of cell c can be J*B bits.

[0410] For convenience, the terminal is described as having B=1 bit for each j value (j=0,1...,J-1), but is not limited thereto.

[0411] Type-1 HARQ-ACK Codebook for Downlink Carrier Switching

[0412] According to one embodiment of the present disclosure, a method for generating a semi-static HARQ-ACK codebook based on downlink carrier switching is disclosed for a terminal.

[0413] Figure 14 is a diagram showing PDSCH reception and HARQ-ACK transmission when two cells are switched every 2 slots.

[0414] Here, the HARQ-ACK can be included in the PUCCH transmitted in slot n. Here, the K1 value can be set to {1, 2, 3, 4}. Here, in slots n-1 and n-2, the terminal can perform downlink reception from Cell A, and in slots n-3 and n-4, the terminal can perform downlink reception from Cell B.

[0415] In FIG. 14, the terminal can receive PDSCH from cell A in slot n-1 and slot n-2, but cannot receive PDSCH from cell B. The terminal can receive PDSCH from cell B in slot n-3 and slot n-4, but cannot receive PDSCH from cell A.

[0416] However, the semi-static HARQ-ACK codebook includes HARQ-ACK bits for slots n-1, n-2, n-3, and n-4 of cell A according to the setting of K1={1,2,3,4} (the j value corresponding to K1 values ​​3 and 4 is M A,c='A' (Included in) can be included. That is, slots that the terminal does not actually receive are also included in the semi-static HARQ-ACK codebook.

[0417] The semi-static HARQ-ACK codebook contains HARQ-ACK bits for slots n-1, n-2, n-3, and n-4 of Cell B according to the setting of K1={1,2,3,4} (the j value corresponding to K1 values ​​1 and 2 is M A,c='B' (Included in) can be included. That is, slots that the terminal does not actually receive are also included in the semi-static HARQ-ACK codebook.

[0418] Therefore, an increase in the size of the semi-static HARQ-ACK codebook and more uplink resources for transmission may be required. Methods to address this are disclosed.

[0419] [Method 1] Union of TDRA Tables

[0420] In the first method, the terminal can generate a semi-static HARQ-ACK codebook by considering two cells as one cell. Here, the two cells may be cells received by a single RF signal receiver. According to the conventional method, the terminal can generate a semi-static HARQ-ACK codebook for each cell. That is, according to the conventional method, for each cell M A,cis determined, and the HARQ-ACK of the PDSCH received from cell c is M A,c It may be included in the corresponding HARQ-ACK bit position depending on.

[0421] According to the first method, for two cells, one M A,c is determined, and the HARQ-ACK of the PDSCH received from Cell A and Cell B is the above one M A,c It may be included in the corresponding HARQ-ACK bit position depending on.

[0422] In the first method, different TDRA tables may be set for the terminal in the first cell and the second cell. According to one method of the present disclosure, the terminal may determine a single TDRA table by combining the TDRA tables of the first cell and the second cell. Here, the single TDRA table may be referred to as the Union of TDRA tables. More specifically, the Union of TDRA tables may include all SLIVs included in the TDRA table of the first cell and all SLIVs included in the TDRA table of the second cell. The SLIVs included in the Union of TDRA tables may be assigned a unique index. If the TDRA table of the first cell and the TDRA table of the second cell contain the same SLIV, the Union of TDRA tables may include only one of the said SLIVs (without duplication).

[0423] For example, let's denote the TDRA table in cell 1 (Cell A) as Table 25 and the TDRA table in cell 2 (Cell B) as Table 26. Here, SLIV1 may be the 1st SLIV, SLIV2 may be the 2nd SLIV, SLIV3 may be the 3rd SLIV, SLIV4 may be the 4th SLIV, and SLIV5 may be the 5th SLIV. In the TDRA table of cell 1 (Cell A), TDRA A={SLIV1, SLIV2, SLIV3, SLIV4} is included, and in the TDRA table of the second cell (Cell B), TDRA B ={SLIV1, SLIV2, SLIV5} may be included.

[0424] According to the prior art, the terminal is the TDRA of the first cell (cell A). A Generate the first semi-static codebook of the first cell (Cell A) based on ={SLIV1, SLIV2, SLIV3, SLIV4}, and the TDRA of the second cell (Cell B) B A second semi-static codebook of the second cell (cell B) can be generated based on ={SLIV1, SLIV2, SLIV5}. And the first semi-static codebook and the second semi-static codebook can be combined to generate a single semi-static codebook.

[0425] For convenience, let us assume that SLIV1, SLIV2, SLIV3, SLIV4, and SLIV5 do not overlap in time. According to the prior art, four HARQ-ACK bits are included in the first semi-static codebook in a slot determined by a single K1 value in the first cell (Cell A). This is because the maximum number of PDSCHs that can be scheduled in a single slot of the first cell (Cell A) can be four, which is the same as the number of SLIVs (SLIV1, SLIV2, SLIV3, SLIV4, and so on, four). Three HARQ-ACK bits are included in the second semi-static codebook in a slot determined by a single K1 value in the second cell (Cell B). This is because the maximum number of PDSCHs that can be scheduled in one slot of the second cell (cell B) can be 3, which is the same as the number of SLIVs (SLIV1, SLIV2, SLIV5, and 3 others).

[0426] The first semi-static codebook and the second semi-static codebook can be combined. Thus, for a single K1 value, the HARQ-ACK bits corresponding to the two cells can be 7 bits. If the terminal receives a PDSCH in the first cell (Cell A), the HARQ-ACK of the PDSCH can be included in the first semi-static codebook based on the SLIV of the PDSCH. If the terminal receives a PDSCH in the second cell (Cell B), the HARQ-ACK of the PDSCH can be included in the second semi-static codebook based on the SLIV of the PDSCH. For the same K1 value, the PDSCH can be received in only one cell. However, according to the conventional method, the first semi-static codebook and the second semi-static codebook are generated separately for the same K1 value.

[0427] According to the present disclosure, a terminal can determine Union of TDRA tables for two cells. The Union of TDRA tables is TDRA A and TDRA B It can be represented as the union of. That is, the Union of TDRA tables is TDRA A ∪TDRA B It may be possible. Therefore, Union of TDRA tables = {SLIV1, SLIV2, SLIV3, SLIV4, SLIV5} may be included. Based on the above Union of TDRA tables, the terminal may generate a semi-static HARQ-ACK codebook for the first cell (Cell A) and the second cell (Cell B).

[0428] For convenience, let us assume that SLIV1, SLIV2, SLIV3, SLIV4, and SLIV5 do not overlap in time. Five HARQ-ACK bits are included in the semi-static codebook in slots determined by a single K1 value in two cells (cell A and cell B). This is because the maximum number of PDSCHs that can be scheduled according to the Union of TDRA tables = {SLIV1, SLIV2, SLIV3, SLIV4, SLIV5} can be 5, which is the same as the number of SLIVs (SLIV1, SLIV2, SLIV3, SLIV4, SLIV5, 5 or more).

[0429] For a single K1 value, the HARQ-ACK bits corresponding to two cells in the terminal may be 5 bits. If the terminal receives PDSCH in the first cell (Cell A), the HARQ-ACK of said PDSCH may be included in the semi-static codebook based on the SLIV of said PDSCH. If the terminal receives PDSCH in the second cell (Cell B), the HARQ-ACK of said PDSCH may be included in the semi-static codebook based on the SLIV of said PDSCH. Since the semi-static codebook is generated based on Union of TDRA tables, HARQ-ACK bits corresponding to all SLIVs of the first cell (Cell A) and the second cell (Cell B) may be included.

[0430]

[0431]

[0432] FIG. 15 is a diagram illustrating a flowchart according to the first method of the present disclosure.

[0433] The terminal can perform the flowchart of Fig. 15 for two cells.

[0434] The set of K1 may contain multiple K1 values. A semi-static HARQ-ACK codebook may be generated in descending order starting from the largest value among the values ​​included in the set of K1. The first K1 value is the highest K1 value, and the index corresponding to said value may be k=0. The second K1 value is the second highest K1 value, and the index corresponding to said value may be k.

[0435] Referring to Fig. 15, the set R may include SLIVs included in the Union of TDRA table based on the TDRA table of two cells. And j=0 and M A,c = It can be set to.

[0436] Referring to Fig. 15, the terminal can continue to perform the following process until the set R becomes an empty set.

[0437] In the first process, the terminal can find the SLIV x with the lowest index of the last symbol among the SLIVs included in the set R.

[0438] In the second process, the terminal can find SLIVs included in the set R that overlap with SLIV x in at least one symbol. If the index of the SLIV is r, b c,k=0,r It can be set to =j. Also, r can be excluded from the set R. If multiple SLIVs overlap with SLIV x, the above process can be performed for the multiple SLIVs. That is, if the indices of the multiple SLIVs are r1 and r2, b c,k=0,r1 =j, b c,k=0,r2 It can be set to =j. Also, r1 and r2 can be excluded from set R. For reference, since SLIV x always overlaps with SLIV x, b x It is set to =j, and x can be excluded from set R.

[0439] In the third process, the terminal is set M A,cYou can add j to set M A,c If j is added to, the terminal may include the HARQ-ACK bit corresponding to said j in the existing semi-static HARQ-ACK codebook. The PDSCH corresponding to the HARQ-ACK bit corresponding to said j is b c,k,,r It is a PDSCH scheduled with SLIV r satisfying =j. And, j can be updated to j+1.

[0440] The terminal can perform the first to third processes for the following K1 values.

[0441] When the terminal performs the first to third processes for all K1 values, the terminal may stop generating the HARQ-ACK codebook for the two cells (cell A and cell B).

[0442] [Method 2] Select maximum number of HARQ-ACK bits across two cells

[0443] In a second method, the terminal can generate a semi-static codebook based on the semi-static codebook having a larger number of bits among the semi-static codebooks generated in each of the two cells.

[0444] Let Table 25 be the TDRA table in Cell 1 (Cell A), and Table 26 be the TDRA table in Cell 2 (Cell B). Here, SLIV1 may be the 1st SLIV, SLIV2 may be the 2nd SLIV, SLIV3 may be the 3rd SLIV, SLIV4 may be the 4th SLIV, and SLIV5 may be the 5th SLIV. In the TDRA table of Cell 1 (Cell A), TDRA A ={SLIV1, SLIV2, SLIV3, SLIV4} is included, and in the TDRA table of the second cell (Cell B), TDRA B={SLIV1, SLIV2, SLIV5} may be included. Let us assume that SLIV1, SLIV2, SLIV3, SLIV4, and SLIV5 do not overlap in time. The terminal can receive up to 4 PDSCHs in one slot of the first cell. And, the terminal can receive up to 3 PDSCHs in one slot of the second cell. Therefore, the terminal may only need HARQ-ACK bits for receiving up to 4 PDSCHs per slot. That is, the HARQ-ACK bits required for one slot may be 4 bits. Therefore, for one K1 value, only the maximum HARQ-ACK bits required for one slot can be included in the semi-static HARQ-ACK codebook.

[0445] The terminal is the TDRA of the first cell (Cell A). A Generate the first semi-static codebook of the first cell (Cell A) based on ={SLIV1, SLIV2, SLIV3, SLIV4}, and the TDRA of the second cell (Cell B) B A second semi-static codebook of the second cell (cell B) can be generated based on ={SLIV1, SLIV2, SLIV5}. The terminal can select the semi-static codebook that has more bits among the two semi-static codebooks.

[0446] For convenience, let us assume that SLIV1, SLIV2, SLIV3, SLIV4, and SLIV5 do not overlap in time. Four HARQ-ACK bits are included in the first semi-static codebook in the slot determined by a single K1 value in the first cell (Cell A). This is because the maximum number of PDSCHs that can be scheduled in a single slot of the first cell (Cell A) can be 4, which is the same as the number of SLIVs (SLIV1, SLIV2, SLIV3, SLIV4, and so on, 4). Three HARQ-ACK bits are included in the second semi-static codebook in the slot determined by a single K1 value in the second cell (Cell B). This is because the maximum number of PDSCHs that can be scheduled in one slot of the second cell (cell B) can be 3, which is the same as the number of SLIVs (SLIV1, SLIV2, SLIV5, and 3 others).

[0447] Between the first semi-static codebook and the second semi-static codebook, the semi-static codebook having more bits can be selected. For example, since the first semi-static codebook is 4 bits and the second semi-static codebook is 3 bits, the terminal can select the first semi-static codebook. Thus, for one K1 value, the terminal can generate a semi-static codebook of length 4 bits.

[0448] The semi-static codebook may include one of up to 4 HARQ-ACK bits of PDSCH in the first cell or up to 3 HARQ-ACK bits of PDSCH in the second cell.

[0449] For example, in a slot corresponding to one K1 value, when a terminal receives a PDSCH from a first cell, the HARQ-ACK of the PDSCH may be included in a semi-static codebook based on the SLIV of the PDSCH. Since the terminal may receive up to four PDSCHs from the first cell in a slot corresponding to one K1 value, up to four HARQ-ACK bits (up to 4 bits) may be included in the semi-static codebook. Here, in a slot corresponding to one K1 value, the terminal may not receive a PDSCH from a second cell.

[0450] For example, in a slot corresponding to one K1 value, when a terminal receives a PDSCH from a second cell, the HARQ-ACK of the PDSCH may be included in a semi-static codebook based on the SLIV of the PDSCH. Since the terminal may receive up to three PDSCHs from the second cell in a slot corresponding to one K1 value, up to three HARQ-ACK bits (maximum 3 bits) may be included in the semi-static codebook. Since the semi-static codebook contains 4 bits, HARQ-ACK information may be included in 3 of the 4 bits. And the unused 1 bit may contain NACK. Here, in a slot corresponding to one K1 value, the terminal may not receive a PDSCH from the first cell.

[0451] [Method 3] K1 value is selectively applied

[0452] According to one method of the present disclosure, a terminal may receive a K1 value separately for each of two cells. The terminal may generate a semi-static codebook based on the K1 value set for each cell.

[0453] According to the conventional method, the terminal can receive a K1 value based on the PUCCH setting. Since the setting of the K1 value is included in the PUCCH setting, it can be applied equally to all downlink cells. For example, if the K1 value included in the PUCCH setting is {1, 2, 3, 4}, the K1 values ​​can be used commonly for the first cell (Cell A) and the second cell (Cell B). However, for a single K1 value, the terminal can receive a downlink from only one cell. To solve this, the K1 value can be set for each downlink cell.

[0454] More specifically, a K1 value for the first cell (Cell A) may be set. A K1 value for the second cell (Cell B) may be set. The set of K1 values ​​for the first cell set for the first cell (Cell A) may be denoted as K1_sub_A. The set of K1 values ​​for the second cell set for the second cell (Cell B) may be denoted as K1_sub_B. Here, K1_sub_A and K1_sub_B may be subsets of K1 values ​​included in the PUCCH setting. Here, K1_sub_A and K1_sub_B may be disjoint sets.

[0455] Referring to FIG. 14, the terminal can set K1_sub_A = {1,2} in the first cell (cell A) and set K1_sub_B = {3,4} in the second cell (cell B). When generating a first semi-static codebook for the first cell, the terminal can generate the first semi-static codebook based on the K1_sub_A value, and when generating a second semi-static codebook for the second cell, the terminal can generate the second semi-static codebook based on the K2_sub_A value. Additionally, the terminal can generate a semi-static codebook by combining the first semi-static codebook and the second semi-static codebook.

[0456] The terminal can receive a PDSCH from the first cell (cell A). The slot in which the HARQ-ACK of the PDSCH is transmitted may be a slot corresponding to one of K1_sub_A = {1,2}. For example, the slot in which the HARQ-ACK of the PDSCH received in slot n-2 is transmitted may be slot n-2+1=n-1 or slot n-2+2=n, depending on K1_sub_A = {1,2}.

[0457] FIG. 16 is a diagram illustrating a flowchart according to the third method of the present disclosure.

[0458] FIG. 16 is for a single cell (cell c, where c represents the cell index, and cell c can be cell A or cell B). K1_sub_c can be set in the cell.

[0459] The set of K1 may contain multiple K1 values. A semi-static HARQ-ACK codebook may be generated in descending order starting from the largest value among the values ​​included in the set of K1. The first K1 value is the highest K1 value, and the index corresponding to said value may be k=0. The second K1 value is the second highest K1 value, and the index corresponding to said value may be k.

[0460] Referring to FIG. 16, the terminal can determine whether the selected K1 value is included in the set K1_sub_c. If the selected K1 value is included in the set K1_sub_c, the following operations may be performed for the selected K1 value. If the selected K1 value is not included in the set K1_sub_c, the following operations may not be performed for the selected K1 value, and the process may proceed to the next K1 value.

[0461] Referring to FIG. 16, the set R may include SLIVs contained in the TDRA table set for cell c. And j=0 and M A,c = It can be set to.

[0462] Referring to Fig. 16, the terminal can continue to perform the following process until the set R becomes an empty set.

[0463] In the first process, the terminal can find the SLIV x with the lowest index of the last symbol among the SLIVs included in the set R.

[0464] In the second process, the terminal can find SLIVs included in the set R that overlap with SLIV x in at least one symbol. If the index of the SLIV is r, b c,k=0,r It can be set to =j. Also, r can be excluded from the set R. If multiple SLIVs overlap with SLIV x, the above process can be performed for the multiple SLIVs. That is, if the indices of the multiple SLIVs are r1 and r2, b c,k=0,r1 =j, b c,k=0,r2 It can be set to =j. Also, r1 and r2 can be excluded from set R. For reference, since SLIV x always overlaps with SLIV x, b x It is set to =j, and x can be excluded from set R.

[0465] In the third process, the terminal is set M A,c You can add j to set M A,c If j is added to, the terminal may include the HARQ-ACK bit corresponding to said j in the existing semi-static HARQ-ACK codebook. The PDSCH corresponding to the HARQ-ACK bit corresponding to said j is b c,k,,r It is a PDSCH scheduled with SLIV r satisfying =j. And, j can be updated to j+1.

[0466] The terminal can determine whether the next K1 value is included in K1_sub_c. If the next K1 value is included in K1_sub_c, the first to third processes can be performed for the next K1 value. If the next K1 value is not included in K1_sub_c, the first to third processes are not performed for the next K1 value, and the process can proceed to the next K1 value.

[0467] If the terminal performs the first to third processes for all K1 values, the terminal may stop generating the HARQ-ACK codebook for cell c.

[0468] The third method described above was explained using an example where the terminal receives K1 values ​​set by the base station for each cell, but this does not limit the scope of the present invention. For example, in another method, the terminal may determine the validity of K1 values ​​for each cell without separate settings and consider valid K1 values ​​as K1 values ​​set in the cell.

[0469] For example, referring to FIG. 14, the HARQ-ACK is included in the PUCCH of slot n. Based on slot n, the terminal can determine whether downlink reception is possible in slot n-k1. Here, k1 may be the K1 values ​​included in the PUCCH settings. Let K1={1,2,3,4}. The terminal can determine whether downlink reception of Cell A is possible in slots n-1, n-2, n-3, and n-4. Downlink reception from Cell A may be possible in slots n-1 and n-2. Therefore, the terminal can determine {1,2} using valid K1 values ​​of Cell A. That is, K1_sub_A = {1,2}. The terminal can determine whether downlink reception of Cell B is possible in slots n-1, n-2, n-3, and n-4. Downlink reception from Cell B may be possible in slots n-3 and n-4. Therefore, the terminal can determine {3,4} based on the valid K1 values ​​of cell B. That is, K1_sub_B = {3,4}.

[0470] For K1_sub_A determined by the terminal with valid K1 values ​​of cell A and K1_sub_B determined with valid K1 values ​​of cell B, the third method described above can be applied in the same way.

[0471] [Method 4] Treated like UL symbols

[0472] When generating a semi-static codebook, the R set may include SLIVs from the TDRA table. Then, the terminal may exclude symbols that overlap with UL symbols among the SLIVs included in the R set. In the fourth method, the terminal may exclude SLIVs that overlap with symbols that cannot be received downlink among the SLIVs included in the R set.

[0473] More specifically, the terminal can receive a set of symbols that are capable of downlink reception in the cell via an upper layer signal (RRC signal) from the base station. Based on the above setting, the terminal can determine which symbols are capable of downlink reception and which are not. That is, the terminal can determine whether downlink reception is possible or impossible for a single symbol in the cell. If a symbol is not capable of downlink reception, the symbol may be referred to as an invalid symbol. For reference, the above determination may be made on a per-cell basis. That is, an invalid symbol in one cell may not be an invalid symbol in another cell.

[0474] If the terminal requires a transient period for changing the receiver of the RF signal, the terminal may determine the symbols corresponding to the transient period as invalid symbols. Here, the transient period may be determined based on a value reported as the terminal's capability. That is, the terminal may determine the symbols corresponding to the transient period based on the value reported as the terminal's capability. These symbols may be determined as invalid symbols. Alternatively, the number of symbols corresponding to the transient period may be set by the base station. The terminal may determine the symbols corresponding to the set number of symbols as invalid symbols.

[0475] For a cell, the terminal can determine whether each of the SLIVs included in the set R contains an invalid symbol among the corresponding symbols. If at least one of the symbols corresponding to the SLIV is an invalid symbol, the terminal can exclude the SLIV from the set R.

[0476] According to the fourth method, SLIVs corresponding to symbols that the terminal does not use for downlink reception are excluded from semi-static codebook generation, so HARQ-ACK bits for PDSCHs that cannot be received may not be included.

[0477] FIG. 17 is a drawing illustrating invalid symbols according to one embodiment of the present disclosure.

[0478] Referring to FIG. 17, the terminal can determine that the symbols included in slot n-3 and slot n-4 of cell A are invalid symbols. Therefore, when generating a semi-static codebook for cell A, SLIVs that overlap with the invalid symbols in slot n-3 and slot n-4 can be excluded.

[0479] Referring to FIG. 17, the terminal can determine that the symbols included in slot n-1 and slot n-2 of cell B are invalid symbols. Therefore, when generating a semi-static codebook for cell B, SLIVs that overlap with the invalid symbols in slot n-1 and slot n-2 can be excluded.

[0480] FIG. 18 is a diagram illustrating a flowchart according to the fourth method of the present disclosure.

[0481] The terminal can perform the flowchart of Fig. 18 for each cell.

[0482] The set of K1 may contain multiple K1 values. A semi-static HARQ-ACK codebook may be generated in descending order starting from the largest value among the values ​​included in the set of K1. The first K1 value is the highest K1 value, and the index corresponding to said value may be k=0. The second K1 value is the second highest K1 value, and the index corresponding to said value may be k.

[0483] Referring to FIG. 18, the R set may include SLIVs included in the TDRA table based on the cell's TDRA table. Here, SLIVs that overlap with uplink symbols or overlap with symbols that cannot be received due to DL carrier switching (invalid symbols) may be excluded.

[0484] And j=0 and M A,c = It can be set to.

[0485] Referring to Fig. 18, the terminal can continue to perform the following process until the set R becomes an empty set.

[0486] In the first process, the terminal can find the SLIV x with the lowest index of the last symbol among the SLIVs included in the set R.

[0487] In the second process, the terminal can find SLIVs included in the set R that overlap with SLIV x in at least one symbol. If the index of the SLIV is r, b c,k=0,r It can be set to =j. Also, r can be excluded from the set R. If multiple SLIVs overlap with SLIV x, the above process can be performed for the multiple SLIVs. That is, if the indices of the multiple SLIVs are r1 and r2, b c,k=0,r1 =j, b c,k=0,r2 It can be set to =j. Also, r1 and r2 can be excluded from set R. For reference, since SLIV x always overlaps with SLIV x, b x It is set to =j, and x can be excluded from set R.

[0488] In the third process, the terminal is set M A,c You can add j to set M A,cIf j is added to, the terminal may include the HARQ-ACK bit corresponding to said j in the existing semi-static HARQ-ACK codebook. The PDSCH corresponding to the HARQ-ACK bit corresponding to said j is b c,k,,r It is a PDSCH scheduled with SLIV r satisfying =j. And, j can be updated to j+1.

[0489] The terminal can perform the first to third processes for the following K1 values.

[0490] When the terminal performs the first to third processes for all K1 values, the terminal may stop generating the HARQ-ACK codebook for the two cells (cell A and cell B).

[0491] [Method 5] Codebook is generated by the configuration in one carrier

[0492] In the fifth method, the terminal can generate a semi-static codebook based on one of the two cells.

[0493] The terminal can select one of two cells. For example, the terminal can select the cell with the lower cell index among the two cells. As another example, the terminal can select Pcell among the two cells. As yet another example, the terminal can select the cell among the two cells configured to monitor PDCCH. As yet another example, the terminal can select the cell among the two cells configured to monitor the cell that supports FDD operation. The present invention does not limit the method by which the terminal selects one of two cells to the above examples.

[0494] The terminal can generate a semi-static codebook based on the TDRA table set in a selected cell. For example, let the first cell (cell A) be the selected cell. For one K1 value, the terminal can receive up to 4 PDSCHs in one slot of the first cell. This is because the maximum number of PDSCHs that can be scheduled in one slot of the first cell (cell A) can be 4, which is the same as the number of SLIVs (SLIV1, SLIV2, SLIV3, SLIV4, 4 or more). Therefore, for one K1 value, the terminal can include 4 bits in the semi-static codebook.

[0495] When a terminal receives a PDSCH from a first cell, the HARQ-ACK of the PDSCH may be included in a semi-static codebook based on a SLIV corresponding to the PDSCH. The terminal may receive up to four PDSCHs from the first cell, and 4 bits of HARQ-ACK information for the four PDSCHs may be included in a semi-static codebook.

[0496] When the terminal receives a PDSCH from the second cell, the HARQ-ACK of the PDSCH may be included in a semi-static codebook based on the SLIV corresponding to the PDSCH. More specifically, the terminal may determine among the SLIVs included in the TDRA table of the first cell that overlap with the SLIV corresponding to the PDSCH received from the second cell. One of the overlapping SLIVs may be determined (e.g., the SLIV that starts first among the overlapping SLIVs, the SLIV that ends first among the overlapping SLIVs, or the SLIV with the lowest TDRA index among the overlapping SLIVs). If there are no overlapping SLIVs, the terminal may determine one of the SLIVs included in the TDRA table of the first cell (e.g., the SLIV that starts first, the SLIV that ends first, or the SLIV with the lowest TDRA index). The terminal may include HARQ-ACK information of the received PDSCH at the HARQ-ACK bit position corresponding to the SLIV in the semi-static codebook.

[0497] For example, let's assume that the SLIV of the PDSCH received in the second cell is SLIV1. The terminal can determine which SLIV overlaps with SLIV1 among the SLIVs included in the TDRA table (SLIV1, SLIV2, SLIV3, SLIV4) in the first cell. The overlapping SLIV can be determined to be SLIV1. The terminal may include the HARQ-ACK of the received PDSCH at the HARQ-ACK bit position corresponding to SLIV1 of the first cell.

[0498] [Regarding SPS PDSCH HARQ-ACK]

[0499] The terminal can multiplex the HARQ-ACK bits of the SPS PDSCH and transmit them to the base station. There may be one or more SPS PDSCHs. The method for multiplexing the HARQ-ACK bits of the SPS PDSCH is shown in Table 27.

[0500] Specifically, the terminal for all cells ( ), for all SPS PDSCH settings of the cell( ), for all downlink slots where SPS PDSCH is received ( ), generate HARQ-ACK bits for SPS PDSCH reception ( = HARQ-ACK information bit for this SPS PDSCH reception) can be used.

[0501] Here, if the reception of SPS PDSCH overlaps with uplink UL symbols or cell DTX (discontinuous transmission), the HARQ-ACK of SPS PDSCH may not be generated.

[0502] Here, if an SPS PDSCH is not received due to a collision with another SPS PDSCH, or if it is not received due to the maximum number of PDSCHs that can be received in the slot, HARQ-ACK bits for that SPS PDSCH may not be generated.

[0503]

[0504] Due to DL carrier switching, the terminal can receive the downlink from only one of the two cells during a time interval. Therefore, even if SPS PDSCH is set for both cells, the SPS PDSCH that the terminal can receive is for only one cell. Consequently, the HARQ-ACK bit of the SPS PDSCH may not be generated.

[0505] According to one method of the present disclosure, if an SPS PDSCH of a cell is not received due to DL carrier switching, the HARQ-ACK of the SPS PDSCH may not be generated and may be excluded. This is shown in Table 28. Conventionally, only overlaps with UL symbols or cell-DTX were determined, but according to the present disclosure, SPS PDSCHs that overlap with symbols not received due to DL carrier switching may also be excluded.

[0506]

[0507] [Regarding Type-3 HARQ-ACK Codebook]

[0508] The Type-3 HARQ-ACK codebook (or One-shot codebook) is a method in which the terminal reports all HARQ-ACK information regarding all configured serving cells and HARQ process IDs, the number of TBs per HARQ process, and the number of CBGs (code block groups) per TB. For example, if the terminal has 2 serving cells, 16 HARQ processes per serving cell, 1 TB per HARQ process, and 2 CBGs per TB, the terminal reports a total of 64 (= 2 * 16 * 1 * 2) HARQ-ACK information bits.

[0509] The Type-3 HARQ-ACK codebook can list HARQ-ACK information bits in a specific sequence. The sequence is as follows:

[0510] - Can be sorted according to the ascending order of the serving cell index.

[0511] - Within the same serving cell, they can be sorted in ascending order of HARQ process ID.

[0512] - When multiple TBs are included in the same HARQ process (e.g., in the case of 2-TB transfer), the HARQ-ACK information of the first TB may be aligned ahead of the HARQ-ACK information of the second TB.

[0513] - If the same TB contains multiple CBGs (i.e., in the case of CBG-based PDSCH transmission), they can be sorted in ascending order according to the index of the CBG.

[0514] FIG. 19 is a diagram illustrating a method for transmitting a Type-3 HARQ-ACK codebook according to one embodiment of the present disclosure.

[0515] Referring to FIG. 19, let us assume that the terminal is configured with one downlink serving cell (DL CC, 1900) and one uplink serving cell (UL CC, 1905). Here, the uplink serving cell is a cell that transmits PUCCH (1921). Let us assume that the terminal is configured with 8 (i.e., n8) as the number of HARQ processes in the downlink serving cell (1900), and that one PDSCH is configured to transmit only one TB. Let us also assume that CBG-based transmission is not configured. A Type-3 HARQ-ACK codebook can be generated based on all serving cells, HARQ process IDs, and the number of TBs per HARQ process. Thus, since the terminal is configured with 8 HARQ process IDs in one serving cell and 1 TB per HARQ process, the Type-3 HARQ-ACK codebook can contain 8 bits of HARQ-ACK information.

[0516] The terminal can sort the 8 bits of the type-3 HARQ-ACK codebook in ascending order of HARQ process IDs in the downlink serving cell (1900). Since the terminal has received 8 HARQ process IDs in the downlink serving cell (1900),

[0517] The HARQ-ACK information for HARQ process ID 0 is located at the beginning of the Type-3 HARQ-ACK codebook, and

[0518] The HARQ-ACK information for HARQ process ID 1 is located in the second position of the Type-3 HARQ-ACK codebook, and

[0519] The HARQ-ACK information for HARQ process ID 2 is located in the third position of the Type-3 HARQ-ACK codebook, and

[0520] The HARQ-ACK information for HARQ process ID 3 is located in the fourth position of the Type-3 HARQ-ACK codebook, and

[0521] The HARQ-ACK information for HARQ process ID 4 is located in the fifth position of the Type-3 HARQ-ACK codebook, and

[0522] The HARQ-ACK information for HARQ process ID 5 is located in the sixth position of the Type-3 HARQ-ACK codebook, and

[0523] The HARQ-ACK information for HARQ process ID 6 is located in the seventh position of the Type-3 HARQ-ACK codebook, and

[0524] The HARQ-ACK information for HARQ process ID 7 can be located at the end of the Type-3 HARQ-ACK codebook.

[0525] Referring to FIG. 19, the terminal may receive four PDSCHs from a downlink serving cell (1900). In chronological order, the terminal may receive PDSCH#0 (1910), PDSCH#1 (1911), PDSCH#2 (1912), and PDSCH#3 (1913). The HARQ process ID corresponding to each PDSCH may be indicated by the HARQ process number field of the DCI. PDSCH#0 is indicated by HARQ process ID 3, and let the HARQ-ACK information of PDSCH#0 be a0. PDSCH#1 is indicated by HARQ process ID 1, and let the HARQ-ACK information of PDSCH#1 be a1. PDSCH#2 is indicated by HARQ process ID 6, and let the HARQ-ACK information of PDSCH#2 be a2. And let PDSCH#3 be assigned HARQ process ID 0, and let the HARQ-ACK information of PDSCH#3 be a3. The terminal can include the HARQ-ACK information a0, a1, a2, and a3 in the Type-3 HARQ-ACK codebook according to the ascending order of the HARQ process IDs. That is, since PDSCH#0 has a HARQ process ID of 3, the HARQ-ACK of PDSCH#0, a0, can be included in the fourth bit of the Type-3 HARQ-ACK codebook. Since PDSCH#1 has a HARQ process ID of 1, the HARQ-ACK of PDSCH#1, a1, can be included in the second bit of the Type-3 HARQ-ACK codebook. Since PDSCH#2 has a HARQ process ID of 6, the HARQ-ACK of PDSCH#2, a2, can be included in the seventh bit of the Type-3 HARQ-ACK codebook. Finally, since PDSCH#3 has a HARQ process ID of 0, a3, which is the HARQ-ACK of PDSCH#3, can be included in the first bit of the Type-3 HARQ-ACK codebook.For reference, the Type-3 HARQ-ACK codebook may include NACK (or 0) for HARQ process IDs that the terminal has not received or HARQ process IDs that have already been fed back to the base station.

[0526] The terminal may receive a DCI (1920) instructing the transmission of a Type-3 HARQ-ACK codebook from a downlink serving cell (1900). The terminal may receive instructions from the DCI for a PUCCH (1921) resource to transmit the Type-3 HARQ-ACK codebook. The terminal may transmit the 8-bit Type-3 HARQ-ACK codebook to the PUCCH resource.

[0527] Depending on separate settings, the Type-3 HARQ-ACK codebook may also report the NDI values ​​recently received by the terminal for each serving cell and HARQ process in addition to the HARQ-ACK information. Through these NDI values, the base station can determine whether the PDSCH received for each HARQ process of the terminal is considered an initial transmission or a retransmission.

[0528] If there is no separate report of the corresponding NDI value, if the terminal has already reported HARQ-ACK information for a specific HARQ process before receiving the DCI requesting the Type-3 HARQ-ACK codebook from the base station, the terminal maps the HARQ process to NACK; otherwise, it maps the HARQ-ACK information bits to the PDSCH received for each HARQ process.

[0529] The number of serving cells, the number of HARQ processes, the number of TBs, and the number of CBGs can each be configured. If no separate configuration is established for each, the terminal may consider the number of serving cells to be 1, the number of HARQ processes to be 8, the number of TBs to be 1, and the number of CBGs to be 1. Additionally, the number of HARQ processes may vary per serving cell. Furthermore, the value of the number of TBs may vary per serving cell or per BWP within a serving cell. Additionally, the number of CBGs may vary per serving cell.

[0530] One reason a Type-3 HARQ-ACK codebook is required is that a terminal may be unable to transmit a PUCCH or PUSCH containing HARQ-ACK information for a PDSCH due to reasons such as channel connection failure or overlap with other high-priority channels. Therefore, it is reasonable for the base station to request the terminal to report only the relevant HARQ-ACK information without the need to reschedule a separate PDSCH. Accordingly, the terminal may be able to receive a request from the base station to transmit a Type-3 HARQ-ACK codebook via an upper-level signal or L1 signal (e.g., a specific field within the DCI) and to schedule the PUCCH resource for which the codebook will be transmitted.

[0531] The terminal may include an indicator that indicates the transmission of the Type-3 HARQ-ACK codebook in DCI format. The indicator may indicate 0 or 1.

[0532] When a terminal receives a DCI format containing 1 as the value of a field requesting the transmission of a Type-3 HARQ-ACK codebook, the terminal may determine a PUCCH or PUSCH resource for transmitting the Type-3 HARQ-ACK codebook in a specific slot indicated by the DCI format. Furthermore, the terminal may multiplex only the Type-3 HARQ-ACK codebook within the PUCCH or PUSCH of the corresponding slot. Additionally, the terminal may assume that the DCI format does not schedule PDSCH. That is, the fields for PDSCH transmission in the DCI format may not be used for scheduling PDSCH. Furthermore, the fields not used for scheduling PDSCH may be used for other purposes.

[0533] The Type-3 HARQ-ACK codebook must include HARQ-ACK information for all serving cells and all HARQ processes based on the information configured by the terminal. Therefore, HARQ-ACK information bits for the PDSCH of HARQ processes that are not actually used must also be included in the codebook as NACKs. Consequently, there is a disadvantage in that the size of the Type-3 HARQ-ACK codebook is large. Therefore, as the size of the uplink control information bits increases, there is a possibility that uplink transmission coverage or transmission reliability may decrease. A HARQ-ACK codebook with a size smaller than the Type-3 HARQ-ACK codebook is required. Such a codebook can be referred to as an enhanced Type-3 HARQ-ACK codebook. For example, an enhanced Type-3 HARQ-ACK codebook can be configured as follows.

[0534] - Type A: A subset of the total set of (configured) serving cells

[0535] - Type B: A subset of the total set of (configured) HARQ process IDs

[0536] - Type C: Subset of the total set of (configured) TB indexes

[0537] - Type D: A subset of the total set of (configured) CBG indices

[0538] - Type E: A combination of at least two of the above types A to D.

[0539] The enhanced Type-3 HARQ-ACK codebook may have at least one feature of Types A through E and may be composed of one or more sets. Instead of a subset of Types A through E, the entire set may be included. The meaning of multiple sets is, for example, that Type A and Type B may exist, or that even if it is Type A, there may be different subsets.

[0540] The terminal may be indicated by an upper layer signal, an L1 signal, or a combination thereof as the type of Enhanced Type-3 HARQ-ACK codebook. For example, as shown in [Table 29] below, an upper layer signal may indicate a set configuration for the HARQ-ACK information bits to be reported by each enhanced Type-3 HARQ-ACK codebook, and it may be possible for one of these values ​​to be indicated by the L1 signal. As shown in [Table 29], it may be possible to individually set which type of enhanced Type-3 HARQ-ACK codebook is set for each index using an upper layer signal. For convenience, this table may be referred to as the enhanced Type-3 HARQ-ACK codebook type table.

[0541] A specific index of the enhanced Type-3 HARQ-ACK codebook type table (e.g., index 3 in [Table 29]) may be used for a Type-3 HARQ-ACK codebook that reports all HARQ-ACK information bits. A Type-3 HARQ-ACK codebook may be indicated by a separate upper signal, or, if there is no upper signal, used as a default value (e.g., ACK or NACK status for all HARQ process IDs).

[0542] [Table 29] Enhanced Type-3 HARQ-ACK Codebook Type Table

[0543]

[0544] For example, when the terminal receives a value indicated by index 1, the terminal may report an enhanced Type-3 HARQ-ACK codebook containing a total of 8 bits of HARQ-ACK information for serving cell I, HARQ process IDs (0 to 7), and TB 1 according to [Table 29]. When the terminal receives a value indicated by index 2, the terminal may report a total of 4 bits of HARQ-ACK information bits for serving cell I, HARQ process IDs (8 to 11), and TB 1 according to [Table 29]. When the terminal receives a value indicated by index 3, the terminal may calculate the total number of HARQ-ACK bits by considering the serving cell set, the total number of HARQ processes per serving cell I, the number of TBs per HARQ process, and the number of CBGs per TB according to [Table 29]. [Table 29] above is merely an example, and the total number of indices may be greater or less than this; furthermore, the range of HARQ process values ​​indicated by each index and / or the information included in the enhanced Type-3 HARQ-ACK codebook may differ. Additionally, [Table 29] above may be information indicated by upper-level signals (e.g., RRC), and a specific index may be notified via DCI. The selection of a specific index in [Table 29] above may be indicated by at least one or a combination thereof among the HARQ process ID, MCS, NDI, RV, frequency resource allocation information, or time resource allocation information in the DCI fields. For example, the size of the DCI bit field indicating a specific index in [Table 29] above It can be determined as. Here represents the total number of indices in [Table 29] set as the upper signal.

[0545] FIG. 20 is a diagram illustrating a method for transmitting an enhanced Type-3 HARQ-ACK codebook according to the present disclosure.

[0546] Specifically, FIG. 20 illustrates a method for transmitting an enhanced Type-3 HARQ-ACK codebook when an enhanced Type-3 HARQ-ACK codebook is configured for a terminal.

[0547] Referring to FIG. 20, let us assume that the terminal is configured with one downlink serving cell (DL CC, 2000) and one uplink serving cell (UL CC, 2005). Here, the uplink serving cell is a cell that transmits PUCCH (2021, 2031). Let us assume that the terminal is configured with 8 (i.e., n8) as the number of HARQ processes in the downlink serving cell (1900), and that one PDSCH is configured to transmit only one TB. Let us also assume that CBG-based transmission is not configured. A Type-3 HARQ-ACK codebook can be generated based on all serving cells, HARQ process IDs, and the number of TBs per HARQ process.

[0548] Referring to FIG. 20, the terminal may receive four PDSCHs from a downlink serving cell (2000). In chronological order, the terminal may receive PDSCH#0 (2010), PDSCH#1 (2011), PDSCH#2 (2012), and PDSCH#3 (2013). The HARQ process ID corresponding to each PDSCH may be indicated by the HARQ process number field of the DCI. PDSCH#0 is indicated by HARQ process ID 3, and let the HARQ-ACK information of PDSCH#0 be a0. PDSCH#1 is indicated by HARQ process ID 1, and let the HARQ-ACK information of PDSCH#1 be a1. PDSCH#2 is indicated by HARQ process ID 6, and let the HARQ-ACK information of PDSCH#2 be a2. And PDSCH#3 was assigned HARQ process ID 0, and let's call the HARQ-ACK information of PDSCH#3 a3.

[0549] Unlike the Type-3 HARQ-ACK codebook transmission of FIG. 19, the terminal may be configured to receive an enhanced Type-3 HARQ-ACK codebook transmission. For example, when the DCI (2020) triggering the enhanced Type-3 HARQ-ACK codebook transmission indicates index 0, the enhanced Type-3 HARQ-ACK codebook (2021) to be transmitted by the terminal may contain only HARQ-ACK information for the HARQ processes {0, 1, 2, 3} out of 8 HARQ processes, and may not contain HARQ-ACK information for the HARQ processes {4, 5, 6, 7}. For example, when the DCI (2030) triggering the transmission of an enhanced Type-3 HARQ-ACK codebook indicates index 1, the enhanced Type-3 HARQ-ACK codebook (2031) to be transmitted by the terminal may contain only HARQ-ACK information for the HARQ processes {4, 5, 6, 7} out of 8 HARQ processes, and may not contain HARQ-ACK information for the HARQ processes {0, 1, 2, 3}. Although not shown in FIG. 20, other indices other than index 0 and 1 may be indicated, and if said index is indicated, an enhanced Type-3 HARQ-ACK codebook containing only HARQ-ACK information for the HARQ processes corresponding to said index may be transmitted.

[0550] Type-3 HARQ-ACK Codebook for Downlink Carrier Switching

[0551] According to one method of the present disclosure, two cells configured in a terminal may share the same HARQ process ID. That is, the terminal may not receive a HARQ process ID individually from the base station for each cell, but may receive a HARQ process ID in units of two cells (or multiple cells).

[0552] For example, a base station may set up to 16 HARQ process IDs for a terminal in a first cell (Cell A) and a second cell (Cell B). The terminal may receive PDSCH from the base station in the first cell (Cell A) and the second cell (Cell B). A unique HARQ process ID may be assigned to the PDSCH received by the terminal, and the unique HARQ process ID may be applied commonly to both cells. In other words, for a PDSCH corresponding to HARQ process ID = x in the first cell (Cell A), retransmission may be performed through a PDSCH scheduled with HARQ process ID = x in the second cell (Cell B).

[0553] The Type-3 HARQ-ACK codebook or enhanced Type-3 HARQ-ACK codebook is generated based on the HARQ process IDs assigned to each cell. Therefore, if N HARQ process IDs are set for both cells in common, N bits of HARQ-ACK bits can be generated for each of the two cells. Consequently, the terminal may include unused HARQ-ACK bits in the Type-3 HARQ-ACK codebook.

[0554] A method to resolve this is disclosed.

[0555] According to one method of the present disclosure, when two cells configured in a terminal share the same HARQ process ID, the terminal may generate a Type-3 HARQ-ACK codebook based on one of the two cells. Here, it may be assumed that all configured HARQ process IDs are used in one cell. That is, when two cells are configured to share N HARQ process IDs, the terminal may generate a Type-3 HARQ-ACK codebook by assuming that all N HARQ process IDs are configured in one cell. Furthermore, even if the terminal receives a PDSCH from the other cell, the HARQ-ACK of the said PDSCH may be included in the Type-3 HARQ-ACK codebook at a position corresponding to the HARQ process ID of said cell.

[0556] FIG. 21 is a diagram illustrating a case where two cells share a HARQ process ID according to one embodiment of the present disclosure.

[0557] Referring to FIG. 21, the terminal may be configured so that the first cell (Cell A) and the second cell (Cell B) share eight HARQ process IDs in common. The terminal may include bits corresponding to eight HARQ process IDs in the first cell (Cell A) and bits corresponding to eight HARQ process IDs in the second cell (Cell B) in a Type-3 HARQ-ACK codebook. If 1 bit of HARQ-ACK information is included per HARQ process ID, the size of the Type-3 HARQ-ACK codebook may be 16 bits.

[0558] According to one method of the present disclosure, a terminal may generate a Type-3 HARQ-ACK codebook based on one of a first cell (cell A) and a second cell (cell B). Here, one cell may be the first cell (cell A). The terminal may generate a Type-3 HARQ-ACK codebook by assuming that eight HARQ process IDs are set in the first cell (cell A). The terminal may include bits corresponding to the eight HARQ process IDs in the first cell (cell A). Thus, the Type-3 HARQ-ACK codebook may include 8 bits. If a PDSCH is received in the second cell (cell B) and HARQ process ID = x, the terminal may include the HARQ-ACK information of the PDSCH in the Type-3 HARQ-ACK codebook at the location where the HARQ process ID of the first cell is x.

[0559] The method for selecting one of the two cells is as follows.

[0560] The terminal may select the cell with the lowest cell index among the two cells. Alternatively, if there is a Pcell among the two cells, the terminal may select the Pcell. If there is a cell among the two cells that monitors PDCCH, the terminal may select the cell that monitors PDCCH. As another example, the terminal may select the cell among the two that supports FDD operation. The present invention is not limited to the above examples regarding the method by which the terminal selects one of the two cells.

[0561] Alternatively, the terminal may generate a Type-3 HARQ-ACK codebook for each of the two cells and select the cell that generates the longer Type-3 HARQ-ACK codebook. Depending on the cell configuration, the number of bits per HARQ process ID is determined, and the length of the Type-3 HARQ-ACK codebook can be determined accordingly. That is, the terminal may select the cell that generates a larger number of bits per HARQ process ID.

[0562] [Regarding Blind Decoding and CCE]

[0563] When a terminal is configured with multiple cells and monitors PDCCH in multiple cells, the number of blind decoding (BD) and CCE of the terminal may be distributed and allocated to the cells. The terminal may monitor PDCCH in each cell based on the number of BDs or CCEs distributed and allocated to the cells.

[0564] More specifically, the terminal's DL BWP subcarrier spacing ( )person Receive the setting of several downlink cells, If so, the terminal in each cell BD of PDCCH candidates exceeding [number] may not be performed. Additionally, the terminal in each cell You may not receive more than 1 CCE.

[0565] The terminal's DL BWP subcarrier spacing ( )person Receive the setting of several downlink cells, If so, the terminal In the downlink cells BD of PDCCH candidates exceeding 10 may not be performed. In addition, the terminal In the downlink cells It may not receive more than a certain number of CCEs. The terminal in each cell BD of PDCCH candidates exceeding [number] may not be performed. The terminal in each cell You may not receive more than 1 CCE.

[0566] Here, if the cell is activated, based on the subcarrier of the cell's active BWP The value of can be determined. If the cell is deactivated, based on the subcarrier of the cell's specific BWP The value of can be determined. Here, a specific BWP may be a BWP set in the parent layer. Here, a specific BWP may be an active BWP used when a disabled cell is enabled.

[0567] Here, is the maximum number of cells or a value determined by terminal capability, and is the maximum number of BDs that the terminal can perform in one slot, and This may be the maximum number of CCEs that a terminal can receive in one slot.

[0568] FIG. 22 is a drawing illustrating a case where PDCCH monitoring is set in two cells according to one embodiment of the present disclosure.

[0569] Referring to FIG. 22, PDCCH monitoring can be configured for two cells. That is, the terminal can monitor the PDCCH at the configured PDCCH monitoring occasion (MO) of the first cell (Cell A) and the second cell (Cell B). Depending on the upper layer configuration, the terminal can receive the downlink from only one of the two cells. Even if PDCCH monitoring is configured for both cells, the terminal can monitor the PDCCH from only one of the two cells during a single time interval. Therefore, even if the terminal is configured for two cells, it is equivalent to the terminal actually monitoring the PDCCH from only one cell. Accordingly, the number of BDs or CCEs can be determined.

[0570] According to one embodiment of the present disclosure, the active BWPs of two cells have the same subcarrier spacing. In this case, two cells can be counted as one cell. For example, if two cells are configured for a terminal and downlink reception occurs in only one of the two cells, if the active BWP has the same subcarrier interval On the other hand, in conventional technology However, according to an embodiment of the present disclosure, It may be. The terminal is the above Based on this, the number of BDs and CCEs to be performed in one slot in each cell can be determined.

[0571] According to one embodiment of the present disclosure, the active BWPs of two cells have different subcarrier intervals. , In this case, two cells can be counted as separate cells.

[0572] According to one embodiment of the present disclosure, the active BWPs of two cells have different subcarrier intervals. , When this happens, two cells can be counted as one cell. For example, two cells are two subcarrier intervals , One cell may be counted as a single cell corresponding to one of the subcarrier intervals. Alternatively, two cells may be counted as a single cell corresponding to the smaller of the two subcarrier intervals. Alternatively, two cells may be counted as a single cell corresponding to the larger of the two subcarrier intervals. Alternatively, if one of the two cells is a Pcell, the two cells may be counted as a single cell corresponding to the subcarrier interval of the Pcell. Alternatively, two cells may be counted as a single cell corresponding to the subcarrier interval of the cell with the lower index among the two cells. Alternatively, two cells may be counted as a single cell corresponding to the subcarrier interval of the cell among the two cells that supports FDD operation.

[0573] [Regarding Timer]

[0574] The terminal may adjust the value of the timer depending on whether it receives PDCCH. The terminal's timer may be decremented (run) at specific intervals, and when the value of the timer becomes 0, the terminal may perform a defined terminal action. If the terminal receives PDCCH, the terminal may start or restart the timer with the value initialized.

[0575] For example, the terminal's behavior regarding the BWP inactivity Timer is shown in Table 30.

[0576] According to Table 30, when a terminal receives a PDCCH from an active BWP or receives a PDCCH scheduling a downlink or uplink from an active BWP, the terminal can start or restart the BWP inactivity Timer (bwp-InactivityTimer) with an initialized value.

[0577]

[0578] Referring to FIG. 22, PDCCH monitoring may be configured for two cells. That is, a terminal may monitor PDCCH at the configured PDCCH monitoring occasion (MO) of the first cell (Cell A) and the second cell (Cell B). Depending on the upper layer configuration, the terminal may receive a downlink in only one of the two cells. Even if PDCCH monitoring is configured for both cells, the terminal may monitor PDCCH in only one of the two cells during a single time interval. Therefore, the terminal may not receive PDCCH during a specific time interval in the active BWP of one cell. However, the terminal's timer (e.g., BWP inactivity timer) may continue to run. Therefore, even if the terminal cannot receive PDCCH in the active BWP of one cell, the value of the timer may continue to decrease and the timer may expire. A method for resolving this is disclosed.

[0579] According to one method of the present disclosure, during a time interval in which a terminal cannot receive a PDCCH from an active BWP of a cell, the terminal may stop the cell's timer (e.g., a BWP inactivity timer). Stopping the timer indicates that the value of the timer is no longer decremented. When the terminal can receive a PDCCH from an active BWP of a cell, the terminal may run the cell's timer. According to the above method, unnecessary decrement of the terminal's timer value can be prevented.

[0580] In this disclosure, the BWP inactive Timer is one example. The method of this disclosure can be applied to any timer that is initialized upon receiving a PDCCH.

[0581] [Regarding Cell Deactivation or Activation]

[0582] The Scell ​​can be activated or deactivated according to the instructions of the base station.

[0583] The terminal may receive a MAC-CE signal from the base station. The MAC-CE signal may indicate the activation or deactivation of the Scell. If deactivation is indicated by the MAC-CE, the terminal may deactivate the Scell ​​after a specific point in time. If activation is indicated by the MAC-CE, the terminal may activate the Scell ​​after a specific point in time. Here, the specific point in time may be, for example, the first slot 3ms after transmitting HARQ-ACK information corresponding to the MAC-CE.

[0584] The terminal can receive the sCellDeactivationTimer from the base station. When the timer expires, the terminal can deactivate the Scell.

[0585] According to one embodiment of the present disclosure, when a terminal can receive a downlink from only one of two cells, at least one of the two cells may be an Scell. When an Scell ​​is deactivated, the terminal may not receive a downlink from the deactivated Scell. In this case, the receiver of the RF signal may no longer need to be changed to the deactivated Scell. In this case, the downlink from the non-deactivated cell (Pcell or another Scell) may continue to be received. That is, even if a time interval during which a downlink is not received from the non-deactivated cell (Pcell or another Scell) is set by an upper layer setting, the terminal may not apply said setting. The terminal may receive a downlink from the non-deactivated cell (Pcell or another Scell) during all time intervals. In other words, when an Scell ​​is deactivated, the terminal may consider that the upper layer setting for the receiver of the RF signal is also deactivated. When the deactivated Scell ​​is reactivated, downlink reception may be performed in only one cell according to the upper layer setting for the receiver of the RF signal.

[0586] FIG. 23 is a diagram illustrating the activation and deactivation of DL switching according to the activation and deactivation of SCell according to one embodiment of the present disclosure.

[0587] Referring to FIG. 23, the second cell (cell B) may be an Scell. The terminal may receive a MAC-CE (2300) instructing the second cell (cell B) to be deactivated. The terminal may deactivate the Scell ​​according to the MAC-CE. Additionally, the terminal may no longer apply DL carrier switching settings according to the RF signal receiver to the first cell (cell A). That is, the terminal may deactivate DL carrier switching (2301). That is, the terminal may receive downlink signals at all time intervals of the first cell (cell A). The terminal may receive a MAC-CE (2350) instructing the second cell (cell B) to be activated. The terminal may activate the Scell ​​according to the MAC-CE. Additionally, the terminal may apply DL carrier switching settings according to the RF signal receiver to the first cell (cell A) and the second cell (cell B). That is, the terminal may activate DL carrier switching (2351). That is, the terminal can receive a downlink signal during a portion of the time interval of the first cell (cell A) and can receive a downlink signal during a portion of the time interval of the second cell (cell B).

[0588] According to one method of the present disclosure, the time at which Scell ​​is enabled or disabled and the time at which DL carrier switching is enabled or disabled may be the same. That is, the time at which DL carrier switching is enabled or disabled may be the first slot after 3ms after the transmission of the HARQ-ACK of MAC-CE indicating the activation or disabled of Scell.

[0589] According to one method of the present disclosure, the time at which an Scell ​​is enabled or disabled and the time at which a DL carrier switching is enabled or disabled may not be the same. For example, an Scell ​​may be enabled or disabled starting from the first slot 3ms after the transmission of a HARQ-ACK of a MAC-CE indicating the enable or disablement of the Scell, but a DL carrier switching may be enabled or disabled at the first slot of the cycle. That is, the enable or disablement of the DL carrier switching may be the first slot of the cycle 3ms after the transmission of a HARQ-ACK of a MAC-CE indicating the enable or disablement of the Scell. Accordingly, the enablement and / or disablement of the DL carrier switching may operate on a cycle basis.

[0590] In the example described above, the activation or deactivation of DL carrier switching was determined based on whether a MAC-CE indicating the activation or deactivation of Scell ​​was received; however, this is for illustrative purposes only and does not limit the scope of the present invention. As an example, according to the present disclosure, a MAC-CE indicating the activation or deactivation of DL carrier switching may be introduced. A terminal may determine whether DL carrier switching is activated or deactivated based on the MAC-CE indicating the activation or deactivation of DL carrier switching. Additionally, based on the MAC-CE indicating the activation or deactivation of DL carrier switching, the terminal may determine whether Scell ​​is activated or deactivated. That is, if DL carrier switching is activated or deactivated, Scell ​​may also be activated or deactivated.

[0591] FIG. 24 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0592] Referring to FIG. 24, the terminal may include a transceiver (referring to a terminal receiver (2400) and a terminal transmitter (2410)), a memory (not shown), a terminal processing unit (2405), or a terminal control unit or processor. Depending on the communication method of the terminal described above, the transceiver (2400, 2410), memory, and terminal processing unit (2405) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. Furthermore, the transceiver, memory, and processor may be implemented in the form of a single chip.

[0593] The transceiver can transmit and receive signals with a base station or another terminal. Here, the signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0594] In addition, the transceiver can receive a signal through a wireless channel and output it to a processor, and transmit the signal output from the processor through a wireless channel.

[0595] Memory can store programs and data necessary for the operation of the terminal. Additionally, memory can store control information or data included in signals transmitted and received by the terminal. Memory may be composed of storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, there may be multiple memories.

[0596] In addition, the processor can control a series of processes to enable the terminal to operate according to the aforementioned embodiment. For example, the processor can receive a DCI composed of two layers and control the components of the terminal to receive multiple PDSCHs simultaneously. There may be multiple processors, and the processors can perform the operation of controlling the components of the terminal by executing a program stored in memory.

[0597] FIG. 25 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0598] Referring to FIG. 25, the base station may include a transceiver unit (referring to a base station receiver unit (2500) and a base station transmitter unit (2510)), a memory (not shown), and a base station processing unit (2505, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver unit (2500, 2510), the memory, and the base station processing unit (2505) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. In addition, the transceiver unit, the memory, and the processor may be implemented in the form of a single chip.

[0599] The transceiver can transmit and receive signals with a terminal or another base station. Here, the signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0600] In addition, the transceiver receives a signal through a wireless channel and outputs it to a processor, and can transmit the signal output from the processor through a wireless channel.

[0601] Memory can store programs and data necessary for the operation of the base station. Additionally, memory can store control information or data included in signals transmitted and received by the base station. Memory can be composed of storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, there may be multiple memories.

[0602] A processor can control a series of processes to enable a base station to operate according to the embodiments of the present disclosure described above. For example, the processor can control each component of the base station to configure two layers of DCIs containing allocation information for a plurality of PDSCHs and to transmit them. There may be multiple processors, and the processors can perform control operations on the components of the base station by executing a program stored in memory.

[0603] Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0604] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of this disclosure.

[0605] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0606] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to the device performing the embodiment of the present disclosure through an external port. Additionally, a separate storage device on the communication network may be connected to the device performing the embodiment of the present disclosure.

[0607] In the specific embodiments of the present disclosure described above, the components included in the invention are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, or even if a component is expressed in the singular form, it may be composed of a plural form.

[0608] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment may be combined to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure may be combined to operate a base station and a terminal. In addition, although the above embodiments are presented based on an FDD LTE system, other variations based on the technical concept of the above embodiments may be implemented in other systems such as a TDD LTE system, 5G, or NR system.

[0609] Meanwhile, the order of description in the drawings illustrating the method of the present invention does not necessarily correspond to the order of execution, and the order of execution may be changed or executed in parallel.

[0610] Alternatively, drawings describing the method of the present invention may omit some components and include only some components to the extent that the essence of the present invention is not impaired.

[0611] In addition, the method of the present invention may be implemented by combining some or all of the contents included in each embodiment within a scope that does not impair the essence of the invention.

[0612] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will understand that modifications can be easily made to other specific forms without altering the technical spirit or essential features of the present disclosure. The scope of the present disclosure is defined by the claims set forth below rather than by the foregoing detailed description, and all modifications or variations derived from the meaning and scope of the claims and their equivalents should be interpreted as being included within the scope of the present disclosure.

Claims

In a method performed by a user device (UE) of a communication system, A step of receiving configuration information from a base station including a bitmap related to a downlink switching pattern for a plurality of slots; A step of identifying a cell corresponding to a first slot based on the bitmap above; and In the first slot, the step of receiving a downlink channel or a downlink signal from the base station on a cell corresponding to the first slot, In the bitmap above, if the bit value corresponding to the first slot is the first value, the first slot corresponds to the first cell, and A method characterized in that, when the bit value corresponding to the first slot in the bitmap is the second value, the first slot corresponds to the second cell. In paragraph 1, The method further includes the step of receiving information from the base station regarding a first period for switching from the first cell to the second cell. A method characterized in that the first period is applied before the last symbol of a time interval including consecutive slots corresponding to the first cell. In paragraph 1, The method further includes the step of receiving information from the base station regarding a second period for switching from the second cell to the first cell. A method characterized in that the second period is applied before the last symbol of a time interval including consecutive slots corresponding to the second cell. In paragraph 1, A method characterized in that the first slot among a plurality of slots indicated by the bitmap corresponds to the first slot of the frame. In paragraph 1, The above second cell corresponds to a secondary cell (SCell), and If the above second cell is disabled, the above setting information is disabled, and A method characterized in that the setting information is activated when the second cell is activated. In a method performed by a base station of a communication system, A step of transmitting configuration information including a bitmap related to a downlink switching pattern for a plurality of slots to a user device (UE); and The step of transmitting a downlink channel or a downlink signal to the UE on a cell corresponding to the first slot in the first slot, and In the bitmap above, if the bit value corresponding to the first slot is the first value, the first slot corresponds to the first cell, and A method characterized in that, when the bit value corresponding to the first slot in the bitmap is the second value, the first slot corresponds to the second cell. In paragraph 6, The method further includes the step of transmitting information regarding a first period for switching from the first cell to the second cell to the UE. A method characterized in that the first period is applied before the last symbol of a time interval including consecutive slots corresponding to the first cell. In paragraph 6, The method further includes the step of transmitting information regarding a second period for switching from the second cell to the first cell to the UE. A method characterized in that the second period is applied before the last symbol of a time interval including consecutive slots corresponding to the second cell. In paragraph 6, A method characterized in that the first slot among a plurality of slots indicated by the bitmap corresponds to the first slot of the frame. In paragraph 6, The above second cell corresponds to a secondary cell (SCell), and If the above second cell is disabled, the above setting information is disabled, and A method characterized in that the setting information is activated when the second cell is activated. In a user device (UE), At least one transceiver; At least one processor connected to the above at least one transceiver so as to be able to communicate; and Connected to communicate with at least one processor and capable of executing individually or in any combination of the at least one processor, the UE Receive configuration information from a base station including a bitmap related to downlink switching patterns for multiple slots, and Identify the cell corresponding to the first slot based on the above bitmap, and A memory that stores a command to receive a downlink channel or a downlink signal from the base station on the cell corresponding to the first slot in the first slot; Includes, In the bitmap above, if the bit value corresponding to the first slot is the first value, the first slot corresponds to the first cell, and A UE characterized in that, when the bit value corresponding to the first slot in the bitmap is the second value, the first slot corresponds to the second cell. In Paragraph 11, The above command causes the UE to receive information from the base station regarding a first period for switching from the first cell to the second cell, and A UE characterized in that the first period is applied before the last symbol of a time interval including consecutive slots corresponding to the first cell. In Paragraph 11, The above command causes the UE to receive information from the base station regarding a second period for switching from the second cell to the first cell, and A UE characterized in that the second period is applied before the last symbol of a time interval including consecutive slots corresponding to the second cell. In Paragraph 11, A UE characterized in that the first slot among the plurality of slots indicated by the bitmap corresponds to the first slot of the frame. In the case of a base station, At least one transceiver; At least one processor connected to the above at least one transceiver so as to be able to communicate; and The base station is connected to communicate with at least one processor and is capable of executing individually or in any combination of the at least one processor. Configuration information including a bitmap related to a downlink switching pattern for multiple slots is transmitted to a user device (UE), and A memory that stores a command to transmit a downlink channel or a downlink signal to the UE on a cell corresponding to the first slot in the first slot; Includes, In the bitmap above, if the bit value corresponding to the first slot is the first value, the first slot corresponds to the first cell, and A base station characterized in that, when the bit value corresponding to the first slot in the bitmap is the second value, the first slot corresponds to the second cell.

Images