Method and device for acquiring channel state information in communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. The present disclosure relates to operations of a UE and a base station in a wireless communication system, and, specifically, to a method and device for acquiring channel state information in a wireless communication system. The present disclosure provides a device and method that can effectively provide services in a mobile communication system.

Description

Method and device for obtaining channel state information in a communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method for obtaining channel state information in a network cooperative communication system and a device capable of performing the same. The present disclosure also relates to a method for transmitting and receiving channel state information in a network cooperative communication system and a device 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 the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

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

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

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] The disclosed embodiment seeks to provide a device and method capable of effectively providing a service in a mobile communication system.

[0009] The technical problems to be achieved in various embodiments of the present disclosure are not limited to those mentioned above, and other technical problems not mentioned can be considered by a person having ordinary skill in the art from various embodiments of the present disclosure described below.

[0010] According to one embodiment of the present disclosure, a method performed by a base station in a communication system comprises the steps of: transmitting, to a terminal via higher layer signaling, a first configuration for channel state information (CSI) reporting and a second configuration for one or more channel state information-reference signal (CSI-RS) resources; transmitting, to the terminal, one or more CSI-RSs based on the one or more CSI-RS resources; receiving, from the terminal, CSI related to the one or more CSI-RSs, the CSI including a first CSI predefined for a radio unit (RU) of the base station, and the first configuration including one or more configurations related to the first predefined CSI; performing decoding for the CSI, the first predefined CSI being decoded in the RU; obtaining scheduling information for a physical downlink shared channel (PDSCH), the scheduling information being related to the CSI; And it may include a step of transmitting DCI (downlink control information) including the scheduling information to the terminal through a PDCCH (physical downlink control channel).

[0011] According to one embodiment of the present disclosure, the one or more configurations include configurations related to an uplink control information (UCI) multiplexing scheme in a physical uplink shared channel (PUSCH), wherein the UCI multiplexing scheme may include: a DM-RS symbol to which a demodulation reference signal (DM-RS) for the PUSCH is mapped includes a first symbol among a plurality of symbols to which the PUSCH is mapped; the predefined first CSI is mapped from an available RE (resource element) in the DM-RS symbol; and when HARQ-ACK (hybrid automatic repeat request acknowledgment) information and the predefined first CSI are multiplexed in the PUSCH, the HARQ-ACK information is mapped after the predefined first CSI is mapped.

[0012] According to one embodiment of the present disclosure, the CSI includes a predefined second CSI for a distributed unit (DU) of the base station, and the one or more configurations include a configuration for a first reporting slot offset and a configuration for a second slot offset, wherein the first reporting slot offset is shorter than the second reporting slot offset, and the predefined first CSI can be received via a PUSCH corresponding to the first slot offset, and the predefined second CSI can be received via a PUSCH corresponding to the second slot offset.

[0013] According to one embodiment of the present disclosure, the one or more settings may include: settings for channel coding schemes for the predefined first CSI, the channel coding schemes being different channel coding schemes according to a bit length of the predefined first CSI; and settings for an additional beta offset for the predefined first CSI received on a PUSCH.

[0014] According to one embodiment of the present disclosure, the method includes receiving terminal capability information related to the predefined first CSI from the terminal, and the first setting may be based on the terminal capability information.

[0015] According to one embodiment of the present disclosure, the decoded predefined first CSI is stored in the RU of the base station and transmitted from the RU of the base station to the DU of the base station, the scheduling information is obtained from the DU of the base station and transmitted from the DU of the base station to the RU of the base station, the scheduling information transmitted from the DU of the base station includes downlink precoder related information and information about a time point at which CSI on which the scheduling information is based is reported, and when the scheduling information transmitted from the DU of the base station based on the information about the time point at which the CSI is reported is identified as being based on CSI reported at a time point earlier than the stored predefined first CSI, the scheduling information is updated by the RU of the base station, and the updated scheduling information is transmitted to the terminal by the RU of the base station, and when a first rank value corresponding to the CSI reported at the previous time point and a second rank value corresponding to the stored predefined first CSI are different, the downlink precoder related information is updated by the RU of the base station. The rank value may be updated to correspond to one of the rank values ​​or the second rank value.

[0016] A base station in a communication system according to one embodiment of the present disclosure includes a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: transmit, to a terminal via higher layer signaling, a first configuration for channel state information (CSI) reporting and a second configuration for one or more channel state information-reference signal (CSI-RS) resources; transmit one or more CSI-RSs to the terminal based on the one or more CSI-RS resources; receive, from the terminal, CSI related to the one or more CSI-RSs, the CSI including a first CSI predefined for a radio unit (RU) of the base station, and the first configuration including one or more configurations related to the first predefined CSI; perform decoding for the CSI, the first predefined CSI being decoded in the RU; obtain scheduling information for a physical downlink shared channel (PDSCH), the scheduling information being related to the CSI; And it can be set to transmit DCI (downlink control information) including the above scheduling information to the terminal through a PDCCH (physical downlink control channel).

[0017] According to one embodiment of the present disclosure, the one or more configurations include configurations related to an uplink control information (UCI) multiplexing scheme in a physical uplink shared channel (PUSCH), wherein the UCI multiplexing scheme may include: a DM-RS symbol to which a demodulation reference signal (DM-RS) for the PUSCH is mapped includes a first symbol among a plurality of symbols to which the PUSCH is mapped; the predefined first CSI is mapped from an available RE (resource element) in the DM-RS symbol; and when HARQ-ACK (hybrid automatic repeat request acknowledgment) information and the predefined first CSI are multiplexed in the PUSCH, the HARQ-ACK information is mapped after the predefined first CSI is mapped.

[0018] According to one embodiment of the present disclosure, the CSI includes a predefined second CSI for a distributed unit (DU) of the base station, and the one or more configurations include a configuration for a first reporting slot offset and a configuration for a second slot offset, wherein the first reporting slot offset is shorter than the second reporting slot offset, and the predefined first CSI can be received via a PUSCH corresponding to the first slot offset, and the predefined second CSI can be received via a PUSCH corresponding to the second slot offset.

[0019] According to one embodiment of the present disclosure, the one or more settings may include: settings for channel coding schemes for the predefined first CSI, the channel coding schemes being different channel coding schemes according to a bit length of the predefined first CSI; and settings for an additional beta offset for the predefined first CSI received on a PUSCH.

[0020] A method performed by a terminal in a communication system according to one embodiment of the present disclosure comprises the steps of: receiving, from a base station via higher layer signaling, a first configuration for channel state information (CSI) reporting and a second configuration for one or more channel state information-reference signal (CSI-RS) resources; receiving, from the base station, one or more CSI-RSs based on the one or more CSI-RS resources; generating CSI associated with the one or more CSI-RSs, the CSI including a first CSI predefined for a radio unit (RU) of the base station, and the first configuration including one or more configurations associated with the first predefined CSI; transmitting the CSI to the base station, the first predefined CSI being transmitted to the RU of the base station; and receiving scheduling information for a physical downlink shared channel (PDSCH) from the base station via a physical downlink control channel (PDCCH), wherein the scheduling information can be associated with the CSI.

[0021] According to one embodiment of the present disclosure, the one or more configurations include configurations related to an uplink control information (UCI) multiplexing scheme in a physical uplink shared channel (PUSCH), wherein the UCI multiplexing scheme may include: a DM-RS symbol to which a demodulation reference signal (DM-RS) for the PUSCH is mapped includes a first symbol among a plurality of symbols to which the PUSCH is mapped; the predefined first CSI is mapped from an available RE (resource element) in the DM-RS symbol; and when HARQ-ACK (hybrid automatic repeat request acknowledgment) information and the predefined first CSI are multiplexed in the PUSCH, the HARQ-ACK information is mapped after the predefined first CSI is mapped.

[0022] According to one embodiment of the present disclosure, the CSI includes a second CSI predefined for a distributed unit (DU) of the base station, and the one or more configurations include a configuration for a first reporting slot offset and a configuration for a second slot offset, wherein the first reporting slot offset is shorter than the second reporting slot offset, and the predefined first CSI can be transmitted through a PUSCH corresponding to the first slot offset, and the predefined second CSI can be transmitted through a PUSCH corresponding to the second slot offset.

[0023] According to one embodiment of the present disclosure, the one or more settings may include: settings for channel coding schemes for the predefined first CSI, the channel coding schemes being different channel coding schemes according to a bit length of the predefined first CSI; and settings for an additional beta offset for the predefined first CSI received on a PUSCH.

[0024] According to one embodiment of the present disclosure, the method includes a step of transmitting terminal capability information related to the predefined first CSI to the base station, wherein the first setting may be related to the terminal capability information.

[0025] A terminal of a communication system according to one embodiment of the present disclosure comprises a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: receive, from a base station through higher layer signaling, a first configuration for channel state information (CSI) reporting and a second configuration for one or more channel state information-reference signal (CSI-RS) resources; receive one or more CSI-RSs from the base station based on the one or more CSI-RS resources; generate CSI related to the one or more CSI-RSs, the CSI including a first CSI predefined for a radio unit (RU) of the base station, and the first configuration including one or more configurations related to the first predefined CSI; transmit the CSI to the base station, the first predefined CSI being transmitted to the RU of the base station; And scheduling information for PDSCH (physical downlink shared channel) is set to be received from the base station through PDCCH (physical downlink control channel), and the scheduling information may be related to the CSI.

[0026] The various embodiments of the present disclosure described above are only some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the various embodiments of the present disclosure can be derived and understood by a person having ordinary skill in the art based on the detailed description to be described below.

[0027] The disclosed embodiment provides a device and method capable of effectively providing a service in a mobile communication system.

[0028] The effects that can be obtained from various embodiments of the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly derived and understood by a person having ordinary skill in the art based on the detailed description below.

[0029] FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0030] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0031] FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to one embodiment of the present disclosure.

[0032] FIG. 4 is a diagram illustrating a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation in a wireless communication system according to one embodiment of the present disclosure.

[0033] FIG. 5 is a diagram of a beam application time that can be considered when using an integrated TCI method in a wireless communication system according to one embodiment of the present disclosure.

[0034] FIG. 6 is a diagram illustrating another MAC-CE structure for activating and indicating a joint TCI state or a separate DL or UL TCI state in a wireless communication system according to one embodiment of the present disclosure.

[0035] Figure 7 is a diagram illustrating an example of an aperiodic CSI reporting method.

[0036] FIG. 8 is a diagram illustrating an example of setting a control region of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0037] FIG. 9 is a diagram illustrating the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0038] Figure 10 illustrates a process for beam setting and activation of PDSCH.

[0039] FIG. 11 is a diagram illustrating an SRS antenna switching operation according to one embodiment of the present disclosure.

[0040] FIG. 12 is a diagram illustrating an example of antenna port configuration and resource allocation for cooperative communication in a wireless communication system according to one embodiment of the present disclosure.

[0041] FIG. 13 is a diagram illustrating an example of configuring downlink control information (DCI) for cooperative communication in a wireless communication system according to one embodiment of the present disclosure.

[0042] Figure 14 is a diagram showing the Enhanced PDSCH TCI state activation / deactivation MAC-CE structure.

[0043] FIG. 15 is a diagram showing an example of elements constituting a base station according to one embodiment of the present disclosure and a process in which the base station acquires channel state information of a terminal through CSI transmitted by the terminal.

[0044] FIG. 16 is another diagram showing an example of a process in which a base station acquires channel state information of a terminal through CSI transmitted by the terminal according to one embodiment of the present disclosure.

[0045] FIG. 17 is a diagram showing the operation of a terminal according to one embodiment of the present disclosure.

[0046] FIG. 18 is a diagram illustrating the operation of a base station according to one embodiment of the present disclosure.

[0047] FIG. 19 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0048] FIG. 20 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0049] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0050] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to ensure that the gist of the present disclosure is conveyed more clearly without obscuring it by omitting unnecessary explanations.

[0051] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0052] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present 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. Like reference numerals designate like elements throughout the specification. In addition, when describing the present disclosure, if a specific description of a related function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions of the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout the specification.

[0053] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may also be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems through some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as judged by a person having skilled technical knowledge.

[0054] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0055] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0056] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, 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'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0057] Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 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.

[0058] As a representative example of the above broadband wireless communication system, the LTE system adopts the OFDM (Orthogonal Frequency Division Multiplexing) method in the downlink (DL) and the SC-FDMA (Single Carrier Frequency Division Multiple Access) method in the uplink (UL). The uplink refers to a wireless link in which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B or base station (BS)), and the downlink refers to a wireless link in which a base station transmits data or control signals to a terminal. The above multiple access method can distinguish the data or control information of each user by allocating and operating the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality.

[0059] As a future communications system beyond LTE, 5G communication systems must be able to freely reflect the diverse needs of users and service providers. Therefore, they must support services that simultaneously satisfy these diverse requirements. Services being considered for 5G communication systems include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0060] eMBB aims to provide data transmission rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to support a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. Furthermore, 5G communication systems must simultaneously provide the peak data rate and an increased user-perceived data rate for terminals. To meet these requirements, improvements in various transmission and reception technologies, including improved multi-input, multi-output (MIMO) transmission technology, are required. Furthermore, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, 5G communication systems can meet the data transmission rates required by 5G communication systems by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or higher 6 GHz band.

[0061] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the IoT, mMTC requires supporting large-scale terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. The IoT requires the ability to support a large number of terminals (e.g., 1,000,000 terminals / km2) within a cell, as it provides communication capabilities through the attachment of various sensors and devices. Furthermore, terminals supporting mMTC are likely to be located in shadow areas, such as basements, beyond cell coverage due to the nature of the service, and thus may require broader coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must be inexpensive, and since frequent battery replacement is unlikely, they may require extremely long battery lifespans, such as 10 to 15 years.

[0062] Finally, URLLC refers to cellular-based wireless communication services used for specific mission-critical purposes. Examples include remote control of robots or machinery, industrial automation, unmanned aerial vehicles (UAVs), remote health care, and emergency alerts. Therefore, URLLC communications must offer extremely low latency and high reliability. For example, URLLC-enabled services must meet air interface latency requirements of less than 0.5 milliseconds and a packet error rate (PER) of 10-5 or lower. Therefore, for services supporting URLLC, 5G systems must provide shorter Transmit Time Intervals (TTIs) than other services, and design considerations may require the allocation of extensive resources in the frequency band to ensure communication link reliability.

[0063] The three 5G services—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. To meet the differing requirements of each service, different transmission and reception techniques and parameters can be used. Of course, 5G is not limited to the three services described above.

[0064] Hereinafter, a / b can be understood as at least one of a or b.

[0065] [NR time-frequency resources]

[0066] Below, the frame structure of the 5G system is described in more detail with reference to drawings.

[0067] Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G system.

[0068] The horizontal axis of Figure 1 represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as 1 OFDM symbol (102) on the time axis and 1 subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can constitute one resource block (RB, 104). One subframe (110) on the time axis can include multiple OFDM symbols (102). For example, the length of one subframe can be 1 ms.

[0069] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0070] Figure 2 illustrates an example of a structure of a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202). One frame (200) can be defined as 10ms. One subframe (201) can be defined as 1ms, and therefore 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). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per 1 subframe (201) is a setting value for the subcarrier spacing. (204, 205) may vary. In the example of Fig. 2, the subcarrier spacing setting value is If =0(204) The case where =1(205) is shown. If =0(204), 1 subframe (201) can be composed of 1 slot (202), =1(205), 1 subframe (201) can be composed of 2 slots (203). That is, the setting value for the subcarrier spacing Number of slots per subframe according to ( ) may vary, and accordingly the number of slots per frame ( ) may vary. Each subcarrier spacing setting According to and can be defined as [Table 1] below.

[0071] [Table 1]

[0072]

[0073] [Bandwidth Part (BWP)]

[0074] Next, the bandwidth part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0075] FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to one embodiment of the present disclosure.

[0076] FIG. 3 shows an example in which the UE bandwidth (300) is set to two bandwidth portions, namely, bandwidth portion #1 (BWP#1) (301) and bandwidth portion #2 (BWP#2) (302). The base station can set one or more bandwidth portions to the UE, and can set the information in [Table 2] below for each bandwidth portion.

[0077] [Table 2]

[0078]

[0079] Of course, the above example is not limited, and in addition to the above configuration information, various parameters related to the bandwidth portion can be configured for the terminal. The above information can be transmitted from the base station to the terminal via upper layer signaling, for example, RRC (Radio Resource Control) signaling. At least one bandwidth portion among the configured one or more bandwidth portions can be activated. Whether or not the configured bandwidth portion is activated can be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via DCI.

[0080] According to some embodiments, a terminal before RRC connection can be configured with an initial bandwidth portion (Initial BWP) for initial access from a base station through a Master Information Block (MIB). More specifically, the terminal can receive configuration information about a control resource set (CORESET) and a search space in which a PDCCH for receiving system information required for initial access (which may correspond to Remaining System Information (RMSI) or System Information Block 1 (SIB1)) and search space can be transmitted through the MIB during the initial access phase. The control space and search space configured by the MIB can each be regarded as identifier (ID) 0. The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for control space #0 through the MIB. Additionally, the base station can notify the terminal of the monitoring cycle and monitoring occasion settings for control area #0, i.e., search space #0, via the MIB. The terminal can consider the frequency range set as control area #0 obtained from the MIB as the initial bandwidth portion for initial access. At this time, the identifier (ID) of the initial bandwidth portion can be considered as 0.

[0081] The settings for the bandwidth supported by the above 5G can be used for various purposes.

[0082] In some embodiments, when the bandwidth supported by a terminal is smaller than the system bandwidth, this can be supported through bandwidth portion configuration. For example, the base station can configure the bandwidth portion frequency location (configuration information 2) for the terminal, thereby allowing the terminal to transmit and receive data at a specific frequency location within the system bandwidth.

[0083] Additionally, in some embodiments, a base station may configure multiple bandwidth segments for a terminal to support different numerologies. For example, to support data transmission and reception using both 15 kHz and 30 kHz subcarrier spacing for a given terminal, two bandwidth segments may be configured with subcarrier spacings of 15 kHz and 30 kHz, respectively. The different bandwidth segments may be frequency-division multiplexed (FDM), and when data is to be transmitted and received using a specific subcarrier spacing, the bandwidth segment configured for that subcarrier spacing may be activated.

[0084] Furthermore, in some embodiments, the base station may configure bandwidth portions with different bandwidth sizes for the terminal for the purpose of reducing power consumption of the terminal. For example, if the terminal supports a very large bandwidth, for example, 100 MHz, and constantly transmits and receives data using that bandwidth, very large power consumption may occur. In particular, monitoring unnecessary downlink control channels using a large bandwidth of 100 MHz in a situation where there is no traffic may be very inefficient in terms of power consumption. To reduce power consumption of the terminal, the base station may configure a bandwidth portion with a relatively small bandwidth, for example, 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.

[0085] In the method for setting the bandwidth portion, terminals prior to RRC connection (Connected) can receive configuration information for the initial bandwidth portion (Initial BWP) through the MIB during the initial access phase. More specifically, the terminal can receive a control region (i.e., CORESET) for a downlink control channel on which a DCI scheduling a System Information Block (SIB) can be transmitted from the MIB of the Physical Broadcast Channel (PBCH). The bandwidth of the control region set by the MIB can be regarded as the initial bandwidth portion, and the terminal can receive the Physical Downlink Shared Channel (PDSCH) on which the SIB is transmitted through the set initial bandwidth portion. In addition to receiving the SIB, the initial bandwidth portion can also be utilized for other system information (Other System Information (OSI), paging, and random access).

[0086] [Bandwidth Part (BWP) Change]

[0087] When one or more bandwidth part values ​​are set for a terminal, the base station can instruct the terminal to change (or switch, transition) the bandwidth part value using the bandwidth part indicator field in the DCI. For example, in FIG. 3, when the currently activated bandwidth part of the terminal is bandwidth part #1 (301), the base station can instruct the terminal to bandwidth part #2 (302) using the bandwidth part indicator in the DCI, and the terminal can perform a bandwidth part change to bandwidth part #2 (302) indicated by the bandwidth part indicator in the received DCI.

[0088] As described above, since DCI-based bandwidth part change can be indicated by DCI scheduling PDSCH or PUSCH, when a terminal receives a bandwidth part change request, it must be able to receive or transmit PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth part. To this end, the standard stipulates the delay time (T) required when changing the bandwidth part. BWP ) and can be defined as in [Table 3] below, for example.

[0089] [Table 3]

[0090]

[0091] The bandwidth-partial change delay time requirement supports Type 1 or Type 2 depending on the terminal's capability. The terminal can report the supported bandwidth-partial delay time type to the base station.

[0092] According to the requirement for bandwidth part change delay time mentioned above, when the terminal receives DCI including bandwidth part change indicator in slot n, the terminal changes to the new bandwidth part indicated by the bandwidth part change indicator in slot n+T. BWP The completion can be done at a later time, and transmission and reception for the data channel scheduled by the DCI can be performed in the new bandwidth portion that has been changed. When the base station wants to schedule a data channel in the new bandwidth portion, the terminal's bandwidth portion change delay time (T BWP ), time domain resource allocation for the data channel can be determined. That is, when the base station schedules the data channel with a new bandwidth portion, the data channel can be scheduled after the bandwidth portion change delay time in the method of determining the time domain resource allocation for the data channel. Accordingly, the terminal can determine whether the DCI instructing the bandwidth portion change is after the bandwidth portion change delay time (TBWP ) may not be expected to indicate a slot offset (K0 or K2) value smaller than that.

[0093] If the terminal receives DCI (e.g., DCI format 1_1 or 0_1) indicating a bandwidth change, the terminal may not perform any transmission or reception during the time period from the third symbol of the slot in which the PDCCH including the DCI is received to the start point of the slot indicated by the slot offset (K0 or K2) value indicated by the time domain resource allocation indicator field in the DCI. For example, if the terminal receives DCI indicating a bandwidth change in slot n and the slot offset value indicated by the 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).

[0094] [CA / DC related]

[0095] FIG. 4 is a diagram illustrating a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation according to one embodiment of the present disclosure.

[0096] Referring to FIG. 4, the wireless protocol of the next-generation mobile communication system is composed of NR SDAP (Service Data Adaptation Protocol S25, S70), NR PDCP (Packet Data Convergence Protocol S30, S65), NR RLC (Radio Link Control S35, S60), and NR MAC (Medium Access Control S40, S55) in the terminal and NR base station, respectively.

[0097] Key features of NR SDAP (S25, S70) may include some of the following:

[0098] - Transfer of user plane data

[0099] - Mapping function between QoS flow and data bearer for both DL and UL

[0100] - Marking function of QoS flow ID for both uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0101] - Ability to map reflective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0102] For the above SDAP layer device, the terminal can be configured by an RRC message for each PDCP layer device, each bearer, or each logical channel, whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device, and when the SDAP header is configured, the terminal can instruct the NAS QoS reflection configuration 1-bit indicator (NAS reflective QoS) and the AS QoS reflection configuration 1-bit indicator (AS reflective QoS) of the SDAP header to update or reset the mapping information for the QoS flow and data bearer of the uplink and downlink. The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a smooth service.

[0103] The main functions of NR PDCP (S30, S65) may include some of the following functions:

[0104] - Header compression and decompression (ROHC only)

[0105] - User data transfer function

[0106] - In-sequence delivery of upper layer PDUs

[0107] - Out-of-sequence delivery of upper layer PDUs

[0108] - PDCP PDU reordering for reception

[0109] - Duplicate detection of lower layer SDUs

[0110] - Retransmission function (Retransmission of PDCP SDUs)

[0111] - Encryption and decryption functions (Ciphering and deciphering)

[0112] - Timer-based SDU discard in uplink.

[0113] The reordering function of the NR PDCP device above refers to a function of reordering PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function of transmitting data directly without considering the order, a function of recording lost PDCP PDUs by reordering the order, a function of reporting a status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs.

[0114] The main functions of NR RLC (S35, S60) may include some of the following functions:

[0115] - Data transfer function (Transfer of upper layer PDUs)

[0116] - In-sequence delivery of upper layer PDUs

[0117] - Out-of-sequence delivery of upper layer PDUs

[0118] - ARQ function (Error Correction through ARQ)

[0119] - Concatenation, segmentation and reassembly of RLC SDUs

[0120] - Re-segmentation of RLC data PDUs

[0121] - Reordering of RLC data PDUs

[0122] - Duplicate detection function

[0123] - Protocol error detection

[0124] - RLC SDU discard function

[0125] - RLC re-establishment function

[0126] In the above, the in-sequence delivery function of the NR RLC device refers to the function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. The in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering a single RLC SDU when it is received divided into multiple RLC SDUs, a function of rearranging received RLC PDUs based on the 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 an NR RLC device may include a function to sequentially deliver to the upper layer only the RLC SDUs up to the lost RLC SDU when there is a lost RLC SDU, or may include a function to sequentially deliver to the upper layer all RLC SDUs received before the timer starts if a predetermined timer has expired even if there is a lost RLC SDU. Alternatively, the in-sequence delivery function of an NR RLC device may include a function to sequentially deliver to the upper layer all RLC SDUs received up to the present if a predetermined timer has expired even if there is a lost RLC SDU.In addition, the RLC PDUs may be processed in the order in which they are received (in the order of arrival, regardless of the order of the sequence number) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, the segments stored in the buffer or to be received later may be received, reconstructed into a complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

[0127] The out-of-sequence delivery function of the NR RLC device mentioned above refers to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order, and may include a function of reassembling and delivering RLC SDUs when one RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing and arranging the RLC SN or PDCP SN of received RLC PDUs to record lost RLC PDUs.

[0128] NR MAC (S40, S55) can be connected to multiple NR RLC layer devices configured in one terminal, and the main functions of NR MAC can include some of the following functions.

[0129] - Mapping function (Mapping between logical channels and transport channels)

[0130] - Multiplexing / demultiplexing of MAC SDUs

[0131] - Scheduling information reporting function

[0132] - HARQ function (Error correction through HARQ)

[0133] - Priority handling between logical channels of one UE

[0134] - Priority handling between UEs by means of dynamic scheduling

[0135] - MBMS service identification function

[0136] - Transport format selection function

[0137] - Padding function

[0138] The NR PHY layer (S45, S50) can perform operations such as channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it over a wireless channel, or demodulating and channel decoding OFDM symbols received over a wireless channel and transmitting them to a higher layer.

[0139] The above wireless protocol structure can have various detailed structures 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 S00. On the other hand, when a base station transmits data to a terminal based on CA (carrier aggregation) using multiple carriers in a single TRP, the base station and the terminal use a protocol structure that has a single structure up to RLC, but multiplexes the PHY layer through the MAC layer, such as S10. As another example, when a base station transmits data to a terminal based on DC (dual connectivity) using multiple carriers in multiple TRPs, the base station and the terminal use a protocol structure that has a single structure up to RLC, but multiplexes the PHY layer through the MAC layer, such as S20.

[0140] [Unified TCI state]

[0141] Hereinafter, a single TCI state indication and activation method based on the unified TCI scheme is described. The unified TCI scheme can refer to a method of integrating and managing the transmission and reception beam management methods, which were distinguished into the TCI state method used for downlink reception of the terminal in the existing Rel-15 and 16 and the spatial relation info method used for uplink transmission, into a TCI state. Therefore, when the terminal is instructed by the base station based on the unified TCI scheme, it can perform beam management using the TCI state even for uplink transmission. If the terminal has set a TCI-State, which is an upper layer signaling with the tci-stateId-r17, which is an upper layer signaling, from the base station, the terminal can perform operations based on the unified TCI scheme using the corresponding TCI-State. The TCI-State can exist in two forms: a joint TCI state or a separate TCI state.

[0142] The first type is a joint TCI state, and the terminal can be instructed by the base station to use both the TCI state to apply to uplink transmission and downlink reception through a single TCI-State. If the terminal is instructed to use a TCI-State based on a joint TCI state, the terminal can use the RS corresponding to qcl-Type1 in the TCI-State based on the joint TCI state to instruct the parameters to use for downlink channel estimation, and the RS corresponding to qcl-Type2 to instruct the parameters to use as a downlink reception beam or reception filter. If the terminal is instructed to use a TCI-State based on a joint TCI state, the terminal can use the RS corresponding to qcl-Type2 in the TCI-State based on the joint DL / UL TCI state to instruct the parameters to use as an uplink transmission beam or transmission filter. In this case, if the terminal is instructed to use a joint TCI state, the terminal can apply the same beam to both uplink transmission and downlink reception.

[0143] The second form is a separate TCI state, in which the terminal can be individually instructed by the base station to select a UL TCI state to apply to uplink transmission and a DL TCI state to apply to downlink reception. If the terminal is instructed to select a UL TCI state, the terminal can be instructed to select parameters to use as an uplink transmission beam or transmission filter using the reference RS or source RS configured in the UL TCI state. If the terminal is instructed to select a DL TCI state, the terminal can be instructed to select parameters to use for downlink channel estimation using the RS corresponding to qcl-Type1 configured in the DL TCI state, and to select parameters to use as a downlink reception beam or reception filter using the RS corresponding to qcl-Type2.

[0144] If the terminal is instructed with both the DL TCI state and the UL TCI state, the terminal can be instructed with parameters to be used as an uplink transmission beam or a transmission filter using the reference RS or source RS set in the corresponding UL TCI state, and can be instructed with parameters to be used for downlink channel estimation using the RS corresponding to qcl-Type1 set in the corresponding DL TCI state, and can be instructed with parameters to be used as a downlink reception beam or a reception filter using the RS corresponding to qcl-Type2. In this case, if the reference RS or source RS set in the DL TCI state and UL TCI state to which the terminal is instructed are different, the terminal can individually apply beams to uplink transmission and downlink reception, respectively, based on the instructed UL TCI state and DL TCI state.

[0145] A terminal can receive a joint TCI state from a base station for each bandwidth part within a specific cell through upper layer signaling up to 128 times, and among the separate TCI states, a DL TCI state can be set for each bandwidth part within a specific cell up to 64 or 128 times through upper layer signaling based on a terminal capability report. Among the separate TCI states, the DL TCI state and the joint TCI state can use the same upper layer signaling structure. For example, if 128 joint TCI states are set and 64 DL TCI states are set among the separate TCI states, the 64 DL TCI states can be included in the 128 joint TCI states.

[0146] Among the separate TCI states, the UL TCI state can be set to a maximum of 32 or 64 upper layer signaling for each specific bandwidth part within a specific cell based on the terminal capability report, and like the relationship between the DL TCI state and the joint TCI state among the separate TCI states, the UL TCI state and the joint TCI state among the separate TCI can also use the same upper layer signaling structure, and the UL TCI state among the separate TCI can use different upper layer signaling structures from the joint TCI state and the DL TCI state among the separate TCI states.

[0147] The use of different or identical upper layer signaling structures may be defined in the specification, or may be distinguished through another upper layer signaling established by the base station based on a terminal capability report containing information on which of the two usage modes the terminal can support.

[0148] The terminal can receive transmission and reception beam-related instructions in an integrated TCI manner using one of the joint TCI state and separate TCI state configured by the base station. The terminal can be configured by the base station via upper layer signaling whether to use either the joint TCI state or separate TCI state.

[0149] The terminal receives transmission / reception beam-related instructions using one of the methods selected from the joint TCI state and the separate TCI state through upper layer signaling. At this time, there may be two transmission / reception beam instruction methods from the base station: a MAC-CE-based instruction method and a MAC-CE-based activation and DCI-based instruction method.

[0150] If a terminal receives a transmission / reception beam-related instruction using a joint TCI state method through upper layer signaling, the terminal can perform a transmission / reception beam application operation by receiving a MAC-CE indicating the joint TCI state from a base station, and the base station can schedule reception of a PDSCH including the MAC-CE through a PDCCH for the terminal. If the MAC-CE includes one joint TCI state, the UE can use the indicated joint TCI state to determine the uplink transmission beam or transmission filter and the downlink reception beam or reception filter starting 3 ms after transmitting a PUCCH including HARQ-ACK information indicating whether reception of the PDSCH including the MAC-CE is successful. If the MAC-CE includes two or more joint TCI states, the UE can confirm that the multiple joint TCI states indicated by the MAC-CE correspond to each code point of the TCI state field of DCI format 1_1 or 1_2 starting 3 ms after transmitting a PUCCH including HARQ-ACK information indicating whether reception of the PDSCH including the MAC-CE is successful. Then, the UE can receive DCI format 1_1 or 1_2 and apply one joint TCI state indicated by the TCI state field in the corresponding DCI to the uplink transmission and downlink reception beams. At this time, DCI format 1_1 or 1_2 may or may not include downlink data channel scheduling information (with DL assignment) or may not include it (without DL assignment).

[0151] If a terminal receives an instruction related to a transmit / receive beam using a separate TCI state method through upper layer signaling, the terminal can perform a transmit / receive beam application operation by receiving a MAC-CE indicating a separate TCI state from a base station, and the base station can schedule reception of a PDSCH including the corresponding MAC-CE to the terminal through a PDCCH. If the MAC-CE includes only one set of separate TCI states, the terminal can determine an uplink transmit beam or transmit filter and a downlink receive beam or receive filter using the separate TCI states included in the indicated separate TCI state set starting from 3 ms after transmitting a PUCCH including HARQ-ACK information indicating whether reception of the corresponding PDSCH was successful. At this time, the separate TCI state set may mean single or multiple separate TCI states that one code point of the TCI state field in DCI format 1_1 or 1_2 can have, and one separate TCI state set may include one DL TCI state, one UL TCI state, or one DL TCI state and one UL TCI state. If there are two or more separate TCI state sets included in the MAC-CE, the UE may confirm that the multiple separate TCI state sets indicated by the MAC-CE correspond to each code point of the TCI state field of DCI format 1_1 or 1_2 starting from 3 ms after transmitting the PUCCH including HARQ-ACK information indicating whether reception for the corresponding PDSCH was successful, and may activate the indicated separate TCI state set.At this time, each code point of the TCI state field of DCI format 1_1 or 1_2 can indicate one DL TCI state, one UL TCI state, or one DL TCI state and one UL TCI state each. The terminal can receive DCI format 1_1 or 1_2 and apply a separate set of TCI states indicated by the TCI state field in the corresponding DCI to the uplink transmission and downlink reception beams. At this time, DCI format 1_1 or 1_2 may include downlink data channel scheduling information (with DL assignment) or may not include it (without DL assignment).

[0152] FIG. 5 is a diagram illustrating beam application times that may be considered when using an integrated TCI scheme in a wireless communication system according to an embodiment of the present disclosure. As described above, a terminal may receive DCI format 1_1 or 1_2 from a base station, including (with DL assignment) or not including (without DL assignment) downlink data channel scheduling information, and apply one joint TCI state or a set of separate TCI states indicated by the TCI state field in the corresponding DCI to uplink transmission and downlink reception beams.

[0153] - DCI format 1_1 or 1_2 with DL assignment (500): If the terminal receives DCI format 1_1 or 1_2 including downlink data channel scheduling information from the base station (501) and indicates one joint TCI state or a separate TCI state set based on the integrated TCI method, the terminal receives a PDSCH scheduled based on the received DCI (505), and can transmit a PUCCH including an HARQ-ACK indicating whether reception of the DCI and the PDSCH is successful (510). At this time, the HARQ-ACK can include the meaning of whether reception of both the DCI and the PDSCH is successful, and if at least one of the DCI and the PDSCH is not received, the terminal can transmit a NACK, and if reception of both is successful, the terminal can transmit an ACK.

[0154] - DCI format 1_1 or 1_2 without DL assignment (550): If the terminal receives DCI format 1_1 or 1_2 from the base station that does not include downlink data channel scheduling information (555) and indicates one joint TCI state or a set of separate TCI states based on the integrated TCI method, the terminal may assume at least one combination of the following for the corresponding DCI.

[0155] ■ Includes scrambled CRC using CS-RNTI.

[0156] ■ The value of all bits assigned to all fields used as RV (Redundancy Version) fields is 1.

[0157] ■ The value of all bits assigned to all fields used as MCS (Modulation and Coding Scheme) fields is 1.

[0158] ■ The value of all bits assigned to all fields used as NDI (New Data Indication) fields is 0.

[0159] ■ For FDRA (Frequency Domain Resource Allocation) Type 0, the value of all bits allocated to the FDRA field is 0, for FDRA Type 1, the value of all bits allocated to the FDRA field is 1, and when the FDRA method is dynamicSwitch, the value of all bits allocated to the FDRA field is 0.

[0160] The terminal can transmit a PUCCH including a HARQ-ACK indicating whether reception was successful for the DCI format 1_1 or 1_2 assuming the above-described matters (560).

[0161] - For both DCI format 1_1 or 1_2 with DL assignment (500) and without DL assignment (550), if a new TCI state indicated through DCI (501, 555) is the same as a TCI state that has already been indicated and applied to an uplink transmission and downlink reception beam, the UE can maintain the previously applied TCI state, and if the new TCI state is different from the previously indicated TCI state, the UE can determine the application time of a joint TCI state or a separate TCI state set that can be indicated from the TCI state field included in the DCI as the time after the first slot (520, 570) after the time equal to BAT (beam application time, 515, 565) after the PUCCH transmission (530, 580), and can use the previously indicated TCI-state until (525, 575) before the corresponding slot (520, 570).

[0162] - For both DCI format 1_1 or 1_2 with DL assignment (500) and without DL assignment (550), the BAT can be set by upper layer signaling based on terminal capability report information as a specific number of OFDM symbols, and the numerology for the BAT and the first slot after the BAT can be determined based on the smallest numerology among all cells to which the joint TCI state or separate TCI state set indicated through the DCI is applied.

[0163] A terminal can apply one joint TCI state indicated through MAC-CE or DCI to reception of control resource sets connected to all terminal-specific search spaces, reception of PDSCHs scheduled as PDCCHs transmitted from the control resource sets, transmission of PUSCHs, and transmission of all PUCCH resources.

[0164] A terminal may apply one separate TCI state set, if one separate TCI state set indicated via MAC-CE or DCI includes one DL TCI state, to reception for control resource sets connected to all terminal-specific search spaces, to reception for PDSCH scheduled as PDCCH transmitted from the control resource set, and to all PUSCH and PUCCH resources based on the previously indicated UL TCI state.

[0165] A terminal can apply a separate TCI state set indicated via MAC-CE or DCI to all PUSCH and PUCCH resources if it includes one UL TCI state, and can apply it to reception of control resource sets connected to all terminal-specific search spaces based on previously indicated DL TCI states, and to reception of PDSCH scheduled as PDCCH transmitted from the corresponding control resource set.

[0166] When a separate set of TCI states indicated via MAC-CE or DCI includes one DL TCI state and one UL TCI state, the terminal may apply the DL TCI state to reception for all control resource sets associated with the terminal-specific search space and to reception for PDSCH scheduled as PDCCH transmitted from the control resource set, and may apply the UL TCI state to all PUSCH and PUCCH resources.

[0167] [Unified TCI state MAC-CE]

[0168] Hereinafter, a single TCI state indication and activation method based on the integrated TCI scheme is described. The terminal receives a PDSCH including the following MAC-CE from the base station, and from 3 slots after transmitting a HARQ-ACK for the corresponding PDSCH to the base station, the terminal can interpret each code point of the TCI state field in DCI format 1_1 or 1_2 based on the information in the MAC-CE received from the base station. That is, the terminal can activate each entry of the MAC-CE received from the base station to each code point of the TCI state field in DCI format 1_1 or 1_2.

[0169] FIG. 6 is a diagram illustrating another MAC-CE structure for activating and indicating a joint TCI state or separate DL or UL TCI state in a wireless communication system according to an embodiment of the present disclosure. The meaning of each field within the MAC-CE structure may be as follows.

[0170] - Serving Cell ID (600): This field can indicate which serving cell the MAC-CE is applied to. The length of this field can be 5 bits. If the serving cell indicated by this field is included in one or more of the upper layer signaling simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3, or simultaneousU-TCI-UpdateList4, the MAC-CE can be applied to all serving cells included in one or more of the lists simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3, or simultaneousU-TCI-UpdateList4 that include the serving cell indicated by this field.

[0171] - DL BWP ID (605): This field can indicate to which DL BWP the corresponding MAC-CE applies, and the meaning of each code point in this field can correspond to each code point of the bandwidth part indicator in the DCI. The length of this field can be 2 bits.

[0172] - UL BWP ID (610): This field can indicate which UL BWP the MAC-CE applies to, and the meaning of each code point in this field can correspond to each code point of the bandwidth part indicator in the DCI. The length of this field can be 2 bits.

[0173] - P i (615): This field can indicate whether each code point in the TCI state field in DCI format 1_1 or 1_2 has multiple TCI states or a single TCI state. If P i If the value of is 1, it means that the corresponding i-th code point has multiple TCI states, which may mean that the corresponding code point may contain a separate DL TCI state and a separate UL TCI state. If P i If the value is 0, it means that the corresponding ith code point has a single TCI state, which may mean that the corresponding code point may contain either a joint TCI state, a separate DCI TCI state, or a separate UL TCI state.

[0174] - D / U (620): This field can indicate whether the TCI state ID field in the same octet is a joint TCI state, a separate DL TCI state, or a separate UL TCI state. If this field is 1, the TCI state ID field in the same octet can be a joint TCI state or a separate DL TCI state, and if this field is 0, the TCI state ID field in the same octet can be a separate UL TCI state.

[0175] - TCI state ID (625): This field can indicate a TCI state that can be identified by the upper layer signaling TCI-StateId. If the D / U field is set to 1, this field can be used to express the TCI-StateId, which can be expressed in 7 bits. If the D / U field is set to 0, the MSB (most significant bit) of this field can be considered a reserved bit, and the remaining 6 bits can be used to express the upper layer signaling UL-TCIState-Id. The maximum number of TCI states that can be activated can be 8 for a joint TCI state and 16 for separate DL or UL TCI states.

[0176] - R: Indicates reserved bit and can be set to 0.

[0177] For the MAC-CE structure of FIG. 6 described above, the terminal can include the third octet including the P1, P2, ..., P8 fields in FIG. 6 in the MAC-CE structure, regardless of whether unifiedTCI-StateType-r17 in MIMOparam-r17 in ServingCellConfig, which is an upper layer signaling, is set to joint or separate. In this case, the terminal can perform TCI state activation using the fixed MAC-CE structure regardless of the upper layer signaling set by the base station. As another example, for the MAC-CE structure of FIG. 6 described above, the terminal can omit the third octet including the P1, P2, ..., P8 fields in FIG. 6 when unifiedTCI-StateType-r17 in MIMOparam-r17 in ServingCellConfig, which is an upper layer signaling, is set to joint. In this case, the terminal can save up to 8 bits of the payload of the corresponding MAC-CE according to the upper layer signaling set by the base station. In addition, all D / U fields located from the fourth octet to the first bit in Fig. 6 can be regarded as R fields, and all corresponding R fields can be set to 0 bits.

[0178] [CSI resource configuration]

[0179] NR has a Channel State Information (CSI) framework that directs base stations to measure and report channel state information (CSI) for terminals. The NR CSI framework can consist of at least two elements: resource settings and report settings. Report settings can reference at least one ID of resource settings to establish a connection relationship with each other.

[0180] According to one embodiment of the present disclosure, resource settings may include information related to a reference signal (RS) for measuring channel state information by a terminal. The base station may configure at least one resource setting for the terminal. For example, the base station and the terminal may exchange signaling information, such as [Table 4], to convey information regarding resource settings.

[0181] [Table 4]

[0182]

[0183] In [Table 4], the signaling information CSI-ResourceConfig contains information about each resource setting. According to the signaling information, each resource setting may include a resource setting index (csi-ResourceConfigId) or a BWP index (bwp-ID) or a time-domain transmission configuration of the resource (resourceType) or a resource set list (csi-RS-ResourceSetList) including at least one resource set. The time-domain transmission configuration of the resource may be set to aperiodic transmission, semi-persistent transmission or periodic transmission. The resource set list may be a set including a resource set for channel measurement or a set including a resource set for interference measurement. If the resource set list is a set including resource sets for channel measurement, each resource set may include at least one resource, which may be an index of a CSI reference signal (CSI-RS) resource or a synchronization / broadcast channel block (SS / PBCH block, SSB). If the resource set list is a set including resource sets for interference measurement, each resource set may include at least one interference measurement resource (CSI interference measurement, CSI-IM).

[0184] For example, if the resource set includes CSI-RS, the base station and the terminal can exchange signaling information as in [Table 5] to convey information about the resource set.

[0185] [Table 5]

[0186]

[0187] In [Table 5], the signaling information NZP-CSI-RS-ResourceSet contains information about each resource set. According to the signaling information, each resource set contains at least information about a resource set index (nzp-CSI-ResourceSetId) or a set of indexes of CSI-RSs included (nzp-CSI-RS-Resources), and may include part of information about a spatial domain transmission filter of the included CSI-RS resource (repetition) or whether the included CSI-RS resource is used for tracking (trs-Info).

[0188] CSI-RS may be the most representative reference signal included in a resource set. The base station and terminal can exchange signaling information, as shown in [Table 6], to convey information about CSI-RS resources.

[0189] [Table 6]

[0190]

[0191] In [Table 6], the signaling information NZP-CSI-RS-Resource contains information about each CSI-RS. The information contained in the signaling information NZP-CSI-RS-Resource may have the following meanings.

[0192] - nzp-CSI-RS-ResourceId: CSI-RS resource index

[0193] - resourceMapping: Resource mapping information for CSI-RS resources

[0194] - powerControlOffset: Ratio between PDSCH EPRE (Energy Per RE) and CSI-RS EPRE

[0195] - powerControlOffsetSS: Ratio between SS / PBCH block EPRE and CSI-RS EPRE

[0196] - scramblingID: scrambling index of the CSI-RS sequence

[0197] - periodicityAndOffset: Transmission period and slot offset of the CSI-RS resource

[0198] - qcl-InfoPeriodicCSI-RS: TCI-state information if the CSI-RS is a periodic CSI-RS.

[0199] The resourceMapping included in the above signaling information NZP-CSI-RS-Resource indicates resource mapping information of the CSI-RS resource, and may include frequency resource resource element (RE) mapping, number of ports, symbol mapping, CDM type, frequency resource density, and frequency band mapping information. The number of ports, frequency resource density, CDM type, and time-frequency axis RE mapping that can be set through this may have a value set in one of the rows of [Table 7] below.

[0200] [Table 7]

[0201]

[0202] [Table 7] shows the frequency resource density (density), CDM type, CSI-RS component RE pattern (pattern) frequency axis and time axis start position that can be set according to the number of CSI-RS ports (X) ), the number of frequency-axis REs (k') and the number of time-axis REs (l') of the CSI-RS component RE pattern (pattern) are represented. The aforementioned CSI-RS component RE pattern may be a basic unit configuring a CSI-RS resource. Through Y=1+max(k') REs on the frequency axis and Z=1+max(l') REs on the time axis, the CSI-RS component RE pattern may be composed of YZ REs. When the number of CSI-RS ports is 1 port, the CSI-RS RE position may be specified without limitation of subcarriers in the PRB (Physical Resource Block), and the CSI-RS RE position may be specified by a 12-bit bitmap. When the number of CSI-RS ports is {2, 4, 8, 12, 16, 24, 32} ports and Y=2, CSI-RS RE positions can be specified for every two subcarriers in the PRB, and the CSI-RS RE positions can be specified by a 6-bit bitmap. When the number of CSI-RS ports is 4 ports and Y=4, CSI-RS RE positions can be specified for every four subcarriers in the PRB, and the CSI-RS RE positions can be specified by a 3-bit bitmap. Similarly, time axis RE positions can be specified by a bitmap of a total of 14 bits.

[0203] [CSI report configuration]

[0204] According to one embodiment of the present disclosure, a report setting can have a connection relationship with at least one ID of a resource setting by referencing the ID of the resource setting, and the resource setting(s) having a connection relationship with the report setting provide configuration information including information on a reference signal for measuring channel information. When the resource setting(s) having a connection relationship with the report setting are used for measuring channel information, the measured channel information can be used for reporting channel information according to a reporting method set in the report setting having the connection relationship.

[0205] According to one embodiment of the present disclosure, report settings may include configuration information related to a CSI reporting method. For example, a base station and a terminal may exchange signaling information as shown in [Table 8] to convey information regarding report settings.

[0206] [Table 8]

[0207]

[0208]

[0209]

[0210] In [Table 8], the signaling information CSI-ReportConfig contains information about each report setting. The information contained in the signaling information CSI-ReportConfig may have the following meanings.

[0211] - reportConfigId: report setting index

[0212] - carrier: serving cell index

[0213] - resourcesForChannelMeasurement: resource setting index for channel measurement that has a relationship with report settings

[0214] - csi-IM-ResourcesForInterference: Resource setting index containing CSI-IM resources for interference measurement that have a relationship with report settings.

[0215] - nzp-CSI-RS-ResourcesForInterference: Resource setting index containing CSI-RS resources for interference measurement that are linked to report settings.

[0216] - reportConfigType: Indicates the time axis transmission settings and transmission channel of the channel report, and can have aperiodic transmission or semi-persistent PUCCH (Physical Uplink Control Channel) transmission or semi-periodic PUSCH transmission or periodic transmission settings.

[0217] - reportQuantity: Indicates the type of channel information to be reported. It can have the types of channel information ('cri-RI-PMI-CQI', 'cri-RI-i1', 'cri-RI-i1-CQI', 'cri-RI-CQI', 'cri-RSRP', 'ssb-Index-RSRP', 'cri-RI-LI-PMI-CQI') when no channel report is transmitted and when a channel report is transmitted. Here, the elements included in the types of channel information mean CQI (Channel Quality Indicator), PMI (Precoding Matric Indicator), CRI (CSI-RS Resource Indicator), SSBRI (SS / PBCH block Resource Indicator), Layer Indicator(LI), Rank Indicator(RI), and / or L1-RSRP (Reference Signal Received Power).

[0218] - reportFreqConfiguration: Indicates whether the reported channel information includes only information about the entire wideband or information about each subband. If it includes information about each subband, it can have configuration information about the subband that contains the channel information.

[0219] - timeRestrictionForChannelMeasurements: Whether the reference signal for channel measurement among the reference signals referenced by the reported channel information has a time axis restriction.

[0220] - timeRestrictionForInterferenceMeasurements: Whether the time axis of the reference signal for interference measurement is restricted among the reference signals referenced by the reported channel information.

[0221] - codebookConfig: Codebook information referenced by the channel information being reported

[0222] - groupBasedBeamReporting: Whether to group beams in channel reporting

[0223] - cqi-Table: CQI table index referenced by the reported channel information

[0224] - subbandSize: Index indicating the subband size of channel information

[0225] - non-PMI-PortIndication: Port mapping information referenced when reporting non-PMI channel information.

[0226] When the base station instructs channel information reporting through upper layer signaling or L1 signaling, the terminal can perform channel information reporting by referring to the above-mentioned configuration information included in the instructed report setting.

[0227] The base station can instruct the terminal to report channel state information (CSI) through upper layer signaling, including RRC (Radio Resource Control) signaling or MAC (Medium Access Control) CE (Control Element) signaling, or L1 signaling (e.g., common DCI, group-common DCI, terminal-specific DCI).

[0228] For example, a base station can instruct a terminal to perform an aperiodic channel information report (CSI report) through higher layer signaling or DCI using DCI format 0_1. The base station sets a parameter for the aperiodic CSI report of the terminal, or a plurality of CSI report trigger states including parameters for the CSI report, through higher layer signaling. The parameters for the CSI report or the CSI report trigger states can include a set including a slot interval or a possible slot interval between a PDCCH including the DCI and a PUSCH including the CSI report, a reference signal ID for channel state measurement, a type of channel information to be included, etc. When the base station instructs the terminal to perform some of the multiple CSI report trigger states through the DCI, the terminal reports channel information according to the CSI report settings of the report settings set in the instructed CSI report trigger states. The channel information reporting can be performed through a PUSCH scheduled with DCI format 0_1. The time domain resource allocation of the PUSCH including the CSI report of the terminal can be performed through the slot interval with the PDCCH indicated through the DCI, the start symbol and symbol length indication within the slot for the time domain resource allocation of the PUSCH, etc. For example, the position of the slot in which the PUSCH including the CSI report of the terminal is transmitted can be indicated through the slot interval with the PDCCH indicated through the DCI, and the start symbol and symbol length within the slot can be indicated through the time domain resource assignment field of the DCI described above.

[0229] For example, a base station can instruct a terminal to transmit a semi-persistent CSI report on the PUSCH via DCI using DCI format 0_1. The base station can activate or deactivate the semi-persistent CSI report transmitted on the PUSCH via DCI scrambled with SP-CSI-RNTI. When the semi-persistent CSI report is activated, the terminal can periodically report channel information according to the configured slot interval. When the semi-persistent CSI report is deactivated, the terminal can stop the activated periodic channel information reporting. The base station configures a parameter for the terminal's semi-persistent CSI report or multiple CSI report trigger states including the parameters for the semi-persistent CSI report through upper layer signaling. Parameters for a CSI report, or a CSI report trigger state, may include a set including a slot interval or possible slot intervals between a PDCCH including DCI indicating a CSI report and a PUSCH including the CSI report, a slot interval between a slot in which upper layer signaling indicating a CSI report is activated and a PUSCH including the CSI report, a slot interval period of the CSI report, a type of channel information included, etc. When a base station activates some of a plurality of CSI report trigger states or some of a plurality of report settings for a terminal through upper layer signaling or DCI, the terminal may report channel information according to a report setting included in the indicated CSI report trigger state or a CSI report setting set in the activated report setting.The above channel information reporting can be performed through a PUSCH that is semi-persistently scheduled with DCI format 0_1 ​​scrambled with SP-CSI-RNTI. The time domain resource allocation of the PUSCH including the CSI report of the terminal can be performed through the slot interval period of the CSI report, the slot interval with respect to the slot in which upper layer signaling is activated, the slot interval with respect to the PDCCH indicated through DCI, the start symbol and symbol length indication within the slot for time domain resource allocation of the PUSCH, etc. For example, the position of the slot in which the PUSCH including the CSI report of the terminal is transmitted can be indicated through the slot interval with respect to the PDCCH indicated through DCI, and the start symbol and symbol length within the slot can be indicated through the time domain resource assignment field of the DCI format 0_1 ​​described above.

[0230] For example, a base station can instruct a terminal to transmit a semi-persistent CSI report to a PUCCH through upper layer signaling such as MAC-CE. Through the MAC-CE signaling, the base station can activate or deactivate the semi-persistent CSI report transmitted to the PUCCH. When the semi-persistent CSI report is activated, the terminal can periodically report channel information according to the configured slot interval. When the semi-persistent CSI report is deactivated, the terminal can stop the activated periodic channel information reporting. The base station configures parameters for the semi-persistent CSI report of the terminal through upper layer signaling. The parameters for the CSI report can include a PUCCH resource through which the CSI report is transmitted, a slot interval period of the CSI report, the type of channel information included, etc. The terminal can transmit the CSI report through the PUCCH. Alternatively, if the PUCCH for the CSI report overlaps with the PUSCH, the CSI report can be transmitted through the PUSCH. The location of the PUCCH transmission slot including the CSI report can be indicated through the slot interval period of the CSI report set through upper layer signaling, the slot interval between the slot in which the upper layer signaling is activated and the PUCCH including the CSI report, and the start symbol and symbol length within the slot can be indicated through the start symbol and symbol length to which the PUCCH resource is allocated set through upper layer signaling.

[0231] For example, a base station can instruct a terminal to perform a periodic CSI report through upper layer signaling. The base station can activate or deactivate the periodic CSI report through upper layer signaling including RRC signaling. When the periodic CSI report is activated, the terminal can periodically report channel information according to a configured slot interval. When the periodic CSI report is deactivated, the terminal can stop the activated periodic channel information reporting. The base station configures a report setting including parameters for the terminal's periodic CSI report through upper layer signaling. The parameters for the CSI report can include a PUCCH resource setting for the CSI report, a slot interval between a slot in which upper layer signaling indicating the CSI report is activated and a PUCCH including the CSI report, a slot interval period of the CSI report, a reference signal ID for channel state measurement, the type of channel information included, etc. The terminal can transmit the CSI report through the PUCCH. Alternatively, if the PUCCH for the CSI report overlaps with the PUSCH, the CSI report can be transmitted on the PUSCH. The position of the slot in which the PUCCH including the CSI report is transmitted can be indicated through the slot interval period of the CSI report set through upper layer signaling, the slot interval between the slot in which the upper layer signaling is activated and the PUCCH including the CSI report, and the start symbol and symbol length within the slot can be indicated through the start symbol and symbol length to which the PUCCH resource is allocated set through upper layer signaling.

[0232] For the aforementioned CSI report setting (CSI-ReportConfig), each report setting CSI-ReportConfig can be associated with one downlink (DL) bandwidth part identified by the upper layer parameter bandwidth part identifier (bwp-id) given by the CSI resource setting, CSI-ResourceConfig, associated with the corresponding report setting. For the time domain reporting operation for each report setting CSI-ReportConfig, 'Aperiodic', 'Semi-Persistent', and 'Periodic' methods are supported, which can be configured from the base station to the terminal by the reportConfigType parameter configured from the upper layer. The semi-persistent CSI reporting method supports 'PUCCH-based semi-persistent (semi-PersistentOnPUCCH)' and 'PUSCH-based semi-persistent (semi-PersistentOnPUSCH)'. For periodic or semi-permanent CSI reporting methods, the UE can receive PUCCH or PUSCH resources for transmitting CSI from the base station through higher-layer signaling. The period and slot offset of the PUCCH or PUSCH resources for transmitting CSI can be given as numerology of the uplink (UL) bandwidth portion configured for CSI report transmission. For aperiodic CSI reporting methods, the UE can receive scheduling of PUSCH resources for transmitting CSI from the base station through L1 signaling (the aforementioned DCI format 0_1).

[0233] For the aforementioned CSI resource setting (CSI-ResourceConfig), each CSI resource setting CSI-ReportConfig can include S (≥1) CSI resource sets (given by the upper layer parameter csi-RS-ResourceSetList). The CSI resource set list can be composed of a non-zero power (NZP) CSI-RS resource set and a SS / PBCH block set, or a CSI-interference measurement (CSI-IM) resource set. Each CSI resource setting can be located in a downlink (DL) bandwidth segment identified by the upper layer parameter bwp-id, and the CSI resource setting can be linked to a CSI reporting setting in the same downlink bandwidth segment. The time domain operation of the CSI-RS resources within the CSI resource setting can be set to one of 'aperiodic', 'periodic', or 'semi-persistent' from the upper layer parameter resourceType. For periodic or semi-permanent CSI resource settings, the number of CSI-RS resource sets can be limited to S=1, and the configured period and slot offset can be given as a numerology of a downlink bandwidth portion identified by bwp-id. A terminal can receive one or more CSI resource settings for channel or interference measurement from a base station through higher layer signaling, and may include, for example, the following CSI resources.

[0234] - CSI-IM resources for interference measurements

[0235] - NZP CSI-RS resources for interference measurements

[0236] - NZP CSI-RS resources for channel measurements

[0237] For CSI-RS resource sets associated with resource settings where the upper layer parameter resourceType is set to 'aperiodic', 'periodic', or 'semi-persistent', the trigger state for the CSI report setting where reportType is set to 'aperiodic' and the resource settings for channel or interference measurements for one or more component cells (CCs) can be set with the upper layer parameter CSI-AperiodicTriggerStateList.

[0238] Aperiodic CSI reporting of a terminal can utilize PUSCH, periodic CSI reporting can utilize PUCCH, and semi-persistent CSI reporting can be performed using PUSCH when triggered or activated by DCI, or PUCCH after activation by MAC control element (MAC CE). As mentioned above, CSI resource settings can also be configured as aperiodic, periodic, or semi-persistent. Combinations between CSI reporting settings and CSI resource settings can be supported based on [Table 9] below.

[0239] [Table 9]

[0240]

[0241] Aperiodic CSI reporting can be triggered by the “CSI request” field of the aforementioned DCI format 0_1 ​​corresponding to scheduling DCI for PUSCH. The UE can monitor the PDCCH, acquire the DCI format 0_1, and acquire scheduling information and a CSI request indicator for the PUSCH. The CSI request indicator can be set to NTS (=0, 1, 2, 3, 4, 5, or 6) bits and can be determined by higher layer signaling (reportTriggerSize). One of one or more aperiodic CSI reporting trigger states that can be set by higher layer signaling (CSI-AperiodicTriggerStateList) can be triggered by the CSI request indicator.

[0242] - If all bits in the CSI request field are 0, this may mean that no CSI report is requested.

[0243] - If the number of CSI trigger states (M) in the configured CSI-AperiodicTriggerStateLite is greater than 2NTs-1, M CSI trigger states can be mapped to 2NTs-1 according to the mapping relationship defined, and one of the trigger states of 2NTs-1 can be indicated by the CSI request field.

[0244] - If the number of CSI trigger states (M) in the configured CSI-AperiodicTriggerStateLite is less than or equal to 2NTs-1, one of the M CSI trigger states can be indicated by the CSI request field.

[0245] [Table 10] below shows an example of the relationship between a CSI request indicator and the CSI trigger state that can be indicated by the indicator.

[0246] [Table 10]

[0247]

[0248] A terminal may perform measurement on a CSI resource within a CSI trigger state triggered by a CSI request field, and may generate CSI (including at least one of the aforementioned CQI, PMI, CRI, SSBRI, LI, RI, or L1-RSRP) therefrom. The terminal may transmit the acquired CSI using a PUSCH scheduled by the corresponding DCI format 0_1. If 1 bit corresponding to the uplink data indicator (UL-SCH indicator) in the DCI format 0_1 ​​indicates "1", uplink data (UL-SCH) and the acquired CSI may be multiplexed and transmitted on the PUSCH resource scheduled by the DCI format 0_1. If 1 bit corresponding to the uplink data indicator (UL-SCH indicator) in DCI format 0_1 ​​indicates "0", only CSI can be mapped and transmitted without uplink data (UL-SCH) to the PUSCH resource scheduled by DCI format 0_1.

[0249] Figure 7 is a diagram illustrating an example of an aperiodic CSI reporting method.

[0250] In an example (700) of FIG. 7, the terminal can monitor the PDCCH (701) to obtain DCI format 0_1, from which it can obtain scheduling information and CSI request information for the PUSCH (705). The terminal can obtain resource information for the CSI-RS (702) to be measured from the received CSI request indicator. The terminal can determine when to perform measurement on the transmitted CSI-RS (702) resource based on the time point of receiving DCI format 0_1 ​​and the parameter (aperiodicTriggeringOffset described above) for the offset in the CSI resource set configuration (e.g., NZP CSI-RS resource set configuration (NZP-CSI-RS-ResourceSet)). More specifically, the terminal can receive an offset value X of the parameter aperiodicTriggeringOffset in the NZP-CSI-RS resource set configuration from the base station through upper layer signaling, and the set offset value X can mean an offset between a slot in which a DCI that triggers aperiodic CSI reporting is received and a slot in which a CSI-RS resource is transmitted. For example, the aperiodicTriggeringOffset parameter value and the offset value X can have a mapping relationship described in [Table 11] below.

[0251] [Table 11]

[0252]

[0253] An example (700) of Fig. 7 shows an example in which the aforementioned offset value is set to X=0. In this case, the terminal can receive the CSI-RS (702) in a slot (corresponding to slot 0 (706) of Fig. 7) in which the DCI format 0_1 ​​that triggers the aperiodic CSI report is received, and can report the CSI information measured with the received CSI-RS to the base station through the PUSCH (705). The terminal can obtain scheduling information (information corresponding to each field of the aforementioned DCI format 0_1) for the PUSCH (705) for CSI reporting from the DCI format 0_1. As an example, the terminal can obtain information on a slot in which the PUSCH (705) is to be transmitted from the aforementioned time domain resource allocation information for the PUSCH (705) in the DCI format 0_1. In an example (700) of FIG. 7, the terminal acquires a K2 value corresponding to a slot offset value for PDCCH-to-PUSCH as 3, and accordingly, the PUSCH (705) can be transmitted in slot 3 (709), which is 3 slots away from slot 0 (706), at the time when the PDCCH (701) is received.

[0254] In an example (710) of FIG. 7, the terminal can monitor the PDCCH (711) to obtain DCI format 0_1, and from this, can obtain scheduling information and CSI request information for the PUSCH (715). The terminal can obtain resource information for the CSI-RS (712) to be measured from the received CSI request indicator. An example (710) of FIG. 7 shows an example in which the offset value for the aforementioned CSI-RS is set to X=1. In this case, the terminal can receive the CSI-RS (712) in a slot (corresponding to slot 0 (716) of FIG. 7) in which the DCI format 0_1 ​​that triggers aperiodic CSI reporting is received, and can report the CSI information measured with the received CSI-RS to the base station through the PUSCH (715).

[0255] An aperiodic CSI report may include at least one or both of CSI part 1 and CSI part 2, and when the aperiodic CSI report is transmitted via PUSCH, it may be multiplexed with a transport block. For multiplexing, a CRC is inserted into the input bits of the aperiodic CSI, and after encoding and rate matching, it may be mapped to a resource element in the PUSCH in a specific pattern and transmitted. The CRC insertion may be omitted depending on the coding method or the length of the input bits. The number of modulation symbols calculated for rate matching when multiplexing CSI Part 1 or CSI part 2 included in the aperiodic CSI report may be calculated as shown in [Table 12] below.

[0256] [Table 12]

[0257]

[0258]

[0259] In particular, in the case of PUSCH repetition transmission methods A and B, the UE can transmit the aperiodic CSI report by multiplexing it only in the first repetition transmission among the PUSCH repetition transmissions. This is because the aperiodic CSI report information to be multiplexed is encoded in a polar code manner, and in this case, in order to be multiplexed in multiple PUSCH repetitions, each PUSCH repetition must have the same frequency and time resource allocation. In particular, in the case of PUSCH repetition type B, each actual repetition can have a different OFDM symbol length, so the aperiodic CSI report can be multiplexed and transmitted only in the first PUSCH repetition.

[0260] In addition, for PUSCH repetition transmission scheme B, if the UE schedules aperiodic CSI reporting without scheduling a transport block or receives a DCI activating semi-persistent CSI reporting, the nominal repetition value may be assumed to be 1 even if the number of PUSCH repetition transmissions configured by upper layer signaling is greater than 1. In addition, if the UE schedules or activates aperiodic or semi-persistent CSI reporting without scheduling a transport block based on PUSCH repetition transmission scheme B, the UE may expect the first nominal repetition to be the same as the first actual repetition. For a PUSCH transmitted including semi-persistent CSI based on PUSCH repetition transmission scheme B without scheduling a DCI after semi-persistent CSI reporting is activated by DCI, if the first nominal repetition is different from the first actual repetition, the transmission for the first nominal repetition may be ignored.

[0261] [CSI computation time]

[0262] When a base station instructs a terminal to perform an aperiodic CSI report or a semi-persistent CSI report through DCI, the terminal can determine whether or not a valid channel report can be performed through the instructed CSI report by considering the channel calculation time (CSI computation time) required for the CSI report. For an aperiodic CSI report or a semi-persistent CSI report instructed through DCI, the terminal can perform a valid CSI report starting from the uplink symbol following the Z symbol after the last symbol included in the PDCCH including the DCI instructing the CSI report. The Z symbol described above may vary depending on the numerology of the downlink bandwidth part to which the PDCCH including the DCI instructing the CSI report corresponds, the numerology of the uplink bandwidth part to which the PUSCH transmitting the CSI report corresponds, and the type or characteristics (report quantity, frequency band granularity, number of ports of the reference signal, codebook type, etc.) of the channel information reported in the CSI report. In other words, in order for a CSI report to be judged as a valid CSI report (if the CSI report is a valid CSI report), the uplink transmission of the CSI report must not be performed before the Zref symbol, including the timing advance. In this case, the Zref symbol is the time starting from the moment when the last symbol of the triggering PDCCH ends. This is an uplink symbol that starts CP (cyclic prefix). Here, the detailed value of Z is as described below. and is numerology. At this time Is The largest of It can be promised that it will use what causes the value, is the subcarrier spacing used for PDCCH transmission, is the subcarrier spacing used for CSI-RS transmission, may refer to the subcarrier spacing of the uplink channel used for transmitting UCI (Uplink control information) for CSI reporting. As another example, Is The largest of It is also possible to promise to use something that causes a value. and The definition of is referred to above. For convenience of future explanation, satisfying the above conditions is referred to as satisfying CSI reporting validity condition 1.

[0263] In addition, if the reference signal for channel measurement for an aperiodic CSI report indicated to a terminal through DCI is an aperiodic reference signal, a valid CSI report can be performed starting from the uplink symbol after the Z' symbol after the last symbol including the reference signal ends, and the above-mentioned Z' symbol may vary depending on the numerology of the downlink bandwidth part corresponding to the PDCCH including the DCI indicating the CSI report, the numerology of the bandwidth corresponding to the reference signal for channel measurement for the CSI report, the numerology of the uplink bandwidth part corresponding to the PUSCH transmitting the CSI report, and the type or characteristics of the channel information reported in the CSI report (report quantity, frequency band granularity, number of ports of the reference signal, codebook type, etc.). In other words, in order for a CSI report to be determined as a valid CSI report (if the CSI report is a valid CSI report), the uplink transmission of the CSI report must not be performed before the Zref' symbol, including the timing advance. At this time, the Zref' symbol starts from the moment when the last symbol of the aperiodic CSI-RS or aperiodic CSI-IM triggered by the triggering PDCCH ends. This is an uplink symbol that starts CP (cyclic prefix). Here, the detailed value of Z' is explained below. and is numerology. At this time Is The largest of It can be promised that it will use what causes the value, is the subcarrier spacing used for triggering PDCCH transmission, is the subcarrier spacing used for CSI-RS transmission, may refer to the subcarrier spacing of the uplink channel used for transmitting UCI (Uplink control information) for CSI reporting. As another example, Is The largest of It can be promised that the value will be used. At this time, and The definition of is referred to above. For convenience of future explanation, satisfying the above conditions is referred to as satisfying CSI reporting validity condition 2.

[0264] If the base station instructs the terminal to perform an aperiodic CSI report for an aperiodic reference signal through DCI, the terminal can perform a valid CSI report starting from the first uplink symbol that satisfies both the point in time Z symbols after the last symbol included in the PDCCH including the DCI indicating the CSI report and the point in time Z' symbols after the last symbol including the reference signal. That is, in the case of aperiodic CSI reporting based on the aperiodic reference signal, both CSI reporting validity conditions 1 and 2 must be satisfied to be considered a valid CSI report.

[0265] If the CSI report time indicated by the base station does not satisfy the CSI computation time requirement, the terminal may determine the CSI report to be invalid and may not consider updating the channel information status for the CSI report.

[0266] The Z, Z' symbols for calculating the CSI computation time mentioned above follow [Table 13] and [Table 14] below. For example, if the channel information reported in the CSI report includes only wideband information, the number of ports of the reference signal is 4 or less, there is one reference signal resource, and the codebook type is 'typeI-SinglePanel' or the type of channel information to be reported (report quantity) is 'cri-RI-CQI', the Z, Z' symbols follow [Table 26]. follows the value. This will be referred to as delay requirement 2 in the future. In addition, if the PUSCH containing the CSI report does not contain TB or HARQ-ACK and the CPU occupation of the terminal is 0, the Z and Z' symbols are as in [Table 13]. The value is followed and is named as delay requirement 1. The description of the CPU occupation mentioned above is described in detail below. In addition, when the report quantity is 'cri-RSRP' or 'ssb-Index-RSRP', the Z, Z' symbols are as shown in [Table 14]. Follow the values. X1, X2, X3, and X4 in [Table 14] represent the UE capability for beam reporting time, and KB1 and KB2 in [Table 14] represent the UE capability for beam change time. In case it does not correspond to the type or characteristic of channel information reported in the above-mentioned CSI report, the Z and Z' symbols are in [Table 14]. Follow the value.

[0267] [Table 13]

[0268]

[0269] [Table 14]

[0270]

[0271] [CSI reference resource]

[0272] When a base station instructs a terminal to perform an aperiodic / semi-persistent / periodic CSI report, it may configure a CSI reference resource to determine a reference time and frequency for a channel to be reported in the CSI report. The frequency of the CSI reference resource may be the carrier and subband information for measuring CSI, which are indicated in the CSI report configuration, and these may correspond to the carrier and reportFreqConfiguration in the upper layer signaling CSI-ReportConfig, respectively. The time of the CSI reference resource may be defined based on the time at which the CSI report is transmitted. For example, when instructing to transmit CSI report #X in the uplink slot n' of the carrier and BWP where the CSI report is to be transmitted, the time of the CSI reference resource of CSI report #X may be defined as the carrier on which the CSI report is to be transmitted and the downlink slot n of the BWP, n-nCSI-ref. Downlink slot n is named as μDL for the carrier measuring CSI and the numerology of BWP, and μUL for the carrier transmitting CSI report #X and the numerology of BWP. It is calculated as follows. The slot interval between the downlink slot n and the CSI reference signal, nCSI-ref, is the number of CSI-RS / SSB resources for channel measurement when the CSI report #X transmitted in the uplink slot n' is a semi-persistent or periodic CSI report. If a single CSI-RS / SSB resource is connected to the corresponding CSI report, , and if multiple CSI-RS / SSB resources are connected to the corresponding CSI report. If the CSI report #X transmitted in uplink slot n' is an aperiodic CSI report, the CSI computation time Z' for channel measurement is considered. is calculated as mentioned above is the number of symbols contained in one slot, and in NR Assume that.

[0273] When a base station instructs a terminal to transmit a CSI report in uplink slot n' through upper layer signaling or DCI, the terminal may report CSI by performing channel measurement or interference measurement on a CSI-RS resource, CSI-IM resource, or SSB resource that is transmitted no later than the CSI reference resource slot of the CSI report transmitted in uplink slot n' among the CSI-RS resources, CSI-IM, or SSB resources associated with the CSI report. The CSI-RS resource, CSI-IM resource, or SSB resource associated with the above-mentioned CSI report may mean a CSI-RS resource, CSI-IM resource, or SSB resource included in a resource set set in a resource setting referenced by a report setting for a CSI report of a terminal set through upper layer signaling, or a CSI-RS resource, CSI-IM resource, or SSB resource referenced by a CSI report trigger state including parameters for the CSI report, or a CSI-RS resource, CSI-IM resource, or SSB resource indicated by an ID of a reference signal (RS) set.

[0274] In embodiments of the present disclosure, a CSI-RS / CSI-IM / SSB occasion refers to a transmission time of CSI-RS / CSI-IM / SSB resource(s) determined by a higher layer configuration or a combination of the higher layer configuration and DCI triggering. For example, a semi-persistent or periodic CSI-RS resource determines a slot to be transmitted according to a slot period and slot offset configured by higher layer signaling, and the transmission symbol(s) within the slot are determined according to resource mapping information (resourceMapping). As another example, an aperiodic CSI-RS resource determines a slot to be transmitted according to a slot offset from a PDCCH including a DCI indicating channel reporting configured by higher layer signaling, and the transmission symbol(s) within the slot are determined according to resourceMapping information.

[0275] The above-mentioned CSI-RS occasion can be determined by independently considering the transmission time of each CSI-RS resource or by comprehensively considering the transmission time of one or more CSI-RS resource(s) included in the resource set, and accordingly, the following two interpretations are possible for the CSI-RS occasion according to each resource set configuration.

[0276] - Interpretation 1-1: From the start time of the earliest symbol to the end time of the latest symbol in which one or more specific resources among the CSI-RS resources included in the resource set(s) set in the resource setting referenced by the report setting set for the CSI report are transmitted.

[0277] - Interpretation 1-2: From the start time of the earliest symbol transmitted by the CSI-RS resource to the end time of the latest symbol transmitted by the CSI-RS resource among all CSI-RS resources included in the resource set(s) set in the resource setting referenced by the report setting set for the CSI report.

[0278] In the embodiments of the present disclosure below, it is possible to consider both interpretations of CSI-RS occasions and apply them individually. Furthermore, it is possible to consider both interpretations for CSI-IM occasions and SSB occasions, similar to CSI-RS occasions. However, since the principles are similar to those described above, any redundant explanation will be omitted below.

[0279] In embodiments of the present disclosure, 'CSI-RS / CSI-IM / SSB occasion' for CSI report #X transmitted in 'uplink slot n' means a set of CSI-RS occasions, CSI-IM occasions, and SSB occasions that are not later than the CSI reference resource of CSI report #X transmitted in 'uplink slot n' among CSI-RS resources, CSI-IM resources, and SSB resources included in a resource set set in a resource setting referenced by a report setting set for CSI report #X.

[0280] In the embodiments of the present disclosure, the latest CSI-RS / CSI-IM / SSB occasion among the CSI-RS / CSI-IM / SSB occasions for CSI report #X transmitted in 'uplink slot n' can be interpreted in the following two ways.

[0281] - Interpretation 2-1: A set of occasions including the latest CSI-RS occasion among the CSI-RS occasions for CSI report #X transmitted in uplink slot n', the latest CSI-IM occasion among the CSI-RS occasions for CSI report #X transmitted in uplink slot n', and the latest SSB occasion among the SSB occasions for CSI report #0 transmitted in uplink slot n'.

[0282] - Interpretation 2-2: The latest occasion among all CSI-RS occasions, CSI-IM occasions, and SSB occasions for CSI report #X transmitted in uplink slot n'

[0283] In the embodiments of the present disclosure, it is possible to individually apply both interpretations of the “latest CSI-RS / CSI-IM / SSB occasion among the CSI-RS / CSI-IM / SSB occasions for CSI report #X transmitted in uplink slot n”. In addition, when the two interpretations (Interpretation 1-1, Interpretation 1-2) for the CSI-RS occasion, CSI-IM occasion, and SSB occasion described above are considered, in the embodiments of the present disclosure, it is possible to individually apply the “latest CSI-RS / CSI-IM / SSB occasion among the CSI-RS / CSI-IM / SSB occasions for CSI report #X transmitted in uplink slot n” by considering all four different interpretations (applying Interpretation 1-1 and Interpretation 2-1, applying Interpretation 1-1 and Interpretation 2-2, applying Interpretation 1-2 and Interpretation 2-1, applying Interpretation 1-2 and Interpretation 2-2).

[0284] The base station can instruct the CSI report by considering the amount of channel information that the terminal can calculate simultaneously for the CSI report, i.e. the number of channel information calculation units (CSI processing units, CPUs) of the terminal. The number of channel information calculation units that the terminal can calculate simultaneously If you say so, the terminal Do not expect CSI report instructions from base stations that require more channel information calculations, or We may not consider updating channel information that requires more channel information calculations. The terminal can report to the base station through upper layer signaling or the base station can set it through upper layer signaling.

[0285] The CSI report that the base station instructs the terminal is the total number of channel information that the terminal can calculate simultaneously. It is assumed that some or all of the CPU is used for calculating channel information. For each CSI report, for example, a CSI report The number of channel information calculation units required for If you say so, total The number of channel information calculation units required for a CSI report is It can be said that. The calculation unit of channel information required for each reportQuantity set in the CSI report can be set as shown in [Table 15] below.

[0286] [Table 15]

[0287]

[0288] The number of channel information calculations required by a terminal for multiple CSI reports at a given point in time is the number of channel information calculation units that the terminal can calculate simultaneously. If there are more than this, the terminal may not consider updating channel information for some CSI reports. Among the multiple indicated CSI reports, the CSI reports that do not consider updating channel information are determined at least by considering the CPU time required for calculating channel information for the CSI report and the priority of the channel information being reported. For example, the channel information update may not be considered for the CSI report whose channel information calculation requires the latest CPU time, and it is also possible to preferentially not consider updating channel information for CSI reports with lower channel information priorities.

[0289] The priority of the above channel information can be determined by referring to [Table 16] below.

[0290] [Table 16]

[0291]

[0292] The CSI priority for a CSI report is determined through the priority value PriiCSI(y,k,c,s) in [Table 16]. Referring to [Table 16], the CSI priority value is determined through the type of channel information included in the CSI report, the time axis reporting characteristics of the CSI report (aperiodic, semi-persistent, periodic), the channel on which the CSI report is transmitted (PUSCH, PUCCH), the serving cell index, and the CSI report configuration index. The CSI priority for a CSI report is determined by comparing the priority values ​​PriiCSI(y,k,c,s) and determining that the CSI priority for a CSI report with a smaller priority value is higher.

[0293] If the time taken by the CPU to calculate the channel information required for the CSI report instructed by the base station to the terminal is called CPU occupation time, then the CPU occupation time is determined by considering the type of channel information included in the CSI report (report quantity), the time axis characteristics of the CSI report (aperiodic, semi-persistent, periodic), the slot or symbol occupied by the upper layer signaling or DCI indicating the CSI report, and part or all of the slot or symbol occupied by the reference signal for channel state measurement.

[0294] [PDCCH: DCI related]

[0295] Next, we will specifically explain downlink control information (DCI) in 5G systems.

[0296] 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 a base station to a terminal via DCI. The terminal can monitor a DCI format for fallback and a DCI format for non-fallback for the PUSCH or PDSCH. The fallback DCI format can be composed of fixed fields defined between the base station and the terminal, and the non-fallback DCI format can include configurable fields.

[0297] DCI can be transmitted through the Physical Downlink Control Channel (PDCCH) after going through the channel coding and modulation process. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the UE. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response. That is, the RNTI is not transmitted explicitly, but is included in the CRC calculation process. When the UE receives a DCI message transmitted on the PDCCH, it verifies the CRC using the assigned RNTI. If the CRC verification result is correct, the UE can determine that the message was transmitted to the UE.

[0298] For example, a DCI scheduling a PDSCH for System Information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a Random Access Response (RAR) message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a Paging message may be scrambled with P-RNTI. A DCI notifying a Slot Format Indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a Transmit Power Control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

[0299] DCI format 0_0 can be used as a fallback 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 17] below.

[0300] [Table 17]

[0301]

[0302] DCI format 0_1 ​​can be used as a fallback DCI for scheduling PUSCH, in which case 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 18] below.

[0303] [Table 18]

[0304]

[0305]

[0306] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case 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 19] below.

[0307] [Table 19]

[0308]

[0309] DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, in which case 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 20] below.

[0310] [Table 20]

[0311]

[0312] [PDCCH: CORESET, REG, CCE, Search Space]

[0313] Below, the downlink control channel in a 5G communication system will be described in more detail with reference to drawings.

[0314] FIG. 8 is a diagram illustrating an example of a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system. FIG. 8 illustrates an example in which two control regions (Control Region #1 (801), Control Region #2 (802)) are set within a UE bandwidth part (810) in the frequency axis and within one slot (820) in the time axis. The control regions (801, 802) may be set to specific frequency resources (803) within the entire UE bandwidth part (810) in the frequency axis. The time axis may be set to one or more OFDM symbols, which may be defined as the control region length (Control Resource Set Duration, 804). Referring to the example illustrated in FIG. 8, Control Region #1 (801) is set to a control region length of two symbols, and Control Region #2 (802) is set to a control region length of one symbol.

[0315] The control region in the aforementioned 5G can be established by the base station to the terminal via higher-layer signaling (e.g., system information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Establishing a control region for the terminal means providing information such as the control region identifier, frequency location of the control region, and symbol length of the control region. For example, this information may include the information in [Table 21] below.

[0316] [Table 21]

[0317]

[0318]

[0319] In [Table 21], 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 region.

[0320] FIG. 9 is a diagram illustrating a structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure. FIG. 9 is a diagram showing an example of a basic unit of time and frequency resources constituting a downlink control channel that can be used in 5G. According to FIG. 9, the basic unit of time and frequency resources constituting the control channel can be referred to as a REG (Resource Element Group, 903), and a REG (903) can be defined as 1 OFDM symbol (901) on the time axis and 1 PRB (Physical Resource Block, 902) on the frequency axis, i.e., 12 subcarriers. A base station can concatenate REGs (903) to configure a downlink control channel allocation unit.

[0321] As illustrated in FIG. 9, if the basic unit to which a downlink control channel is allocated in 5G is called a CCE (Control Channel Element, 904), 1 CCE (904) can be composed of multiple REGs (903). Taking the REG (903) illustrated in FIG. 9 as an example, the REG (903) can be composed of 12 REs, and if 1 CCE (904) is composed of 6 REGs (903), 1 CCE (904) can be composed of 72 REs. When a downlink control region is established, the region can be composed of multiple CCEs (904), and a specific downlink control channel can be mapped to one or multiple CCEs (904) and transmitted according to the aggregation level (AL) within the control region. CCEs (904) within the control area are distinguished by numbers, and the numbers of the CCEs (904) can be assigned according to a logical mapping method.

[0322] The basic unit of the downlink control channel illustrated in FIG. 9, that is, the REG (903), may include both the REs to which the DCI is mapped and the areas to which the DMRS (905), which is a reference signal for decoding the REs, is mapped. As shown in FIG. 9, three DMRSs (905) may be transmitted within one REG (903). 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 a 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 (CCEs) that a terminal must attempt to decode at a given aggregation level. Since there are multiple aggregation levels, each of which can be a set of 1, 2, 4, 8, or 16 CCEs, a terminal can have multiple search spaces. A search space set can be defined as the set of search spaces at all configured aggregation levels.

[0323] Search spaces can be categorized into common search spaces and UE-specific search spaces. A certain group of UEs, or all UEs, can search the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling of system information or paging messages. For example, PDSCH scheduling allocation information for transmitting SIBs, including cell operator information, can be received by searching the common search space of the PDCCH. In the case of the common search space, since a certain group of UEs, or all UEs, must receive the PDCCH, it can be defined as a set of pre-arranged CCEs. Scheduling allocation information for UE-specific PDSCH or PUSCH can be received by searching the UE-specific search space of the PDCCH. The UE-specific search space can be defined UE-specifically as a function of the UE's identity and various system parameters.

[0324] In 5G, parameters for the search space for PDCCH can be configured from the base station to the terminal through higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can configure the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the monitoring occasion for each symbol within the slot 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 corresponding search space, the control region index to be monitored for the search space, etc. to the terminal. For example, the information in [Table 22] below can be included.

[0325] [Table 22]

[0326]

[0327]

[0328]

[0329] Depending on the configuration information, the base station may configure one or more search space sets for the terminal. In some embodiments, the base station may configure search space set 1 and search space set 2 for the terminal, and may configure the terminal to monitor DCI format A scrambled with X-RNTI in search space set 1 in a common search space, and may configure the terminal to monitor DCI format B scrambled with Y-RNTI in search space set 2 in a terminal-specific search space.

[0330] According to the configuration information, one or more search space sets 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 terminal-specific search spaces.

[0331] In the common search space, the following combinations of DCI formats and RNTIs can be monitored. Of course, the examples below are not limited to these.

[0332] - 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

[0333] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0334] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0335] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0336] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0337] In a terminal-specific search space, the following combinations of DCI formats and RNTIs can be monitored. Of course, the examples below are not limited to these examples.

[0338] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0339] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0340] The RNTIs specified may follow the definitions and uses below.

[0341] C-RNTI (Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0342] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0343] CS-RNTI (Configured Scheduling RNTI): Used for terminal-specific PDSCH scheduling that is set semi-statically.

[0344] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access phase.

[0345] P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0346] SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0347] INT-RNTI (Interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

[0348] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0349] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0350] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

[0351] The aforementioned specified DCI formats may follow the definitions in [Table 23] below.

[0352] [Table 23]

[0353]

[0354] In 5G, the search space of aggregation level L in the control region p and search space set s can be expressed as in [Mathematical Formula 1] below.

[0355] [Mathematical Formula 1]

[0356]

[0357] - : Integration level

[0358] - : Carrier Index

[0359] - : Total number of CCEs existing within the control region p

[0360] - : slot index

[0361] - : Number of PDCCH candidates for aggregation level L

[0362] - : PDCCH candidate index of aggregation level L

[0363] -

[0364] - , , , , ,

[0365] - : Terminal identifier

[0366] The value can be 0 for a common search space.

[0367] In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's identity (C-RNTI or ID set to the terminal by the base station) and the time index.

[0368] In 5G, since multiple search space sets can be configured with different parameters (e.g., parameters in [Table 22]), the set of search space sets monitored by a terminal at each point in time can be different. 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 can monitor both search space set #1 and search space set #2 in a specific slot, or can monitor either search space set #1 or search space set #2 in a specific slot.

[0369] [SRS related]

[0370] Next, we describe an uplink channel estimation method using the Sounding Reference Signal (SRS) transmission of a terminal. The base station can configure at least one SRS configuration for each uplink BWP to convey configuration information for SRS transmission to the terminal, and can also configure at least one SRS resource set for each SRS configuration. For example, the base station and the terminal can exchange the following upper-level signaling information to convey information regarding the SRS resource set.

[0371] - srs-ResourceSetId: SRS resource set index

[0372] - srs-ResourceIdList: A set of SRS resource indices referenced in the SRS resource set.

[0373] - resourceType: This is the time axis transmission setting of the SRS resource referenced in the SRS resource set, and can be set to one of 'periodic', 'semi-persistent', and 'aperiodic'. If set to 'periodic' or 'semi-persistent', associated CSI-RS information can be provided depending on the usage of the SRS resource set. If set to 'aperiodic', an aperiodic SRS resource trigger list and slot offset information can be provided, and associated CSI-RS information can be provided depending on the usage of the SRS resource set.

[0374] - usage: This is a setting for the usage of the SRS resource referenced in the SRS resource set, and can be set to one of 'beamManagement', 'codebook', 'nonCodebook', and 'antennaSwitching'.

[0375] - alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter settings for adjusting the transmission power of the SRS resource referenced in the SRS resource set.

[0376] The terminal can understand that the SRS resource included in the set of SRS resource indices referenced in the SRS resource set follows the information set in the SRS resource set.

[0377] In addition, the base station and the terminal can transmit and receive upper layer signaling information to convey individual configuration information for the SRS resource. For example, the individual configuration information for the SRS resource can include time-frequency axis mapping information within the slot of the SRS resource, which can include information about frequency hopping within the slot or between slots of the SRS resource. In addition, the individual configuration information for the SRS resource can include the time axis transmission configuration of the SRS resource, which can be set to one of 'periodic', 'semi-persistent', and 'aperiodic'. This can be restricted to have the same time axis transmission configuration as the SRS resource set including the SRS resource. If the time axis transmission configuration of the SRS resource is set to 'periodic' or 'semi-persistent', the SRS resource transmission period and slot offset (e.g., periodicityAndOffset) can additionally be included in the time axis transmission configuration.

[0378] The base station can activate, deactivate, or trigger SRS transmission to the UE through higher layer signaling, including RRC signaling or MAC CE signaling, or L1 signaling (e.g., DCI). For example, the base station can activate or deactivate periodic SRS transmission to the UE through higher layer signaling. The base station can instruct the UE to activate an SRS resource set with resourceType set to periodic through higher layer signaling, and the UE can transmit an SRS resource referenced in the activated SRS resource set. The time-frequency domain resource mapping within the slot of the transmitted SRS resource follows the resource mapping information set in the SRS resource, and the slot mapping, including the transmission period and slot offset, follows the periodicityAndOffset set in the SRS resource. In addition, the spatial domain transmission filter applied to the transmitted SRS resource can refer to the spatial relation information set in the SRS resource, or the associated CSI-RS information set in the SRS resource set that includes the SRS resource. A terminal can transmit SRS resources within an activated uplink BWP for periodic SRS resources activated through upper layer signaling.

[0379] For example, a base station can activate or deactivate semi-persistent SRS transmission to a terminal through upper layer signaling. The base station can instruct the terminal to activate an SRS resource set through MAC CE signaling, and the terminal can transmit an SRS resource referenced in the activated SRS resource set. The SRS resource set activated through MAC CE signaling can be limited to an SRS resource set with resourceType set to semi-persistent. The time-frequency domain resource mapping within the slot of the transmitted SRS resource follows the resource mapping information configured in the SRS resource, and the slot mapping including the transmission period and slot offset follows the periodicityAndOffset configured in the SRS resource. In addition, the spatial domain transmission filter applied to the transmitted SRS resource can refer to the spatial relation information configured in the SRS resource, or the associated CSI-RS information configured in the SRS resource set that includes the SRS resource. If spatial relation info is configured in an SRS resource, the spatial domain transmission filter can be determined by referring to the configuration information for spatial relation info transmitted through MAC CE signaling that activates semi-persistent SRS transmission without following it. The terminal can transmit SRS resources within the activated uplink BWP for the semi-persistent SRS resource activated through upper layer signaling.

[0380] For example, a base station can trigger aperiodic SRS transmission to a terminal via DCI. The base station can indicate one of the aperiodic SRS resource triggers (aperiodicSRS-ResourceTrigger) via the SRS request field of the DCI. The terminal can understand that an SRS resource set including the aperiodic SRS resource trigger indicated via DCI in the aperiodic SRS resource trigger list among the configuration information of the SRS resource set has been triggered. The terminal can transmit an SRS resource referenced in the triggered SRS resource set. The time-frequency domain resource mapping within the slot of the transmitted SRS resource follows the resource mapping information configured in the SRS resource. In addition, the slot mapping of the transmitted SRS resource can be determined through a slot offset between a PDCCH including the DCI and the SRS resource, which can refer to value(s) included in a slot offset set configured in the SRS resource set. Specifically, the slot offset between the PDCCH including DCI and the SRS resource can be applied by applying the value indicated in the time domain resource assignment field of the DCI among the offset value(s) included in the slot offset set configured in the SRS resource set. In addition, the spatial domain transmission filter applied to the transmitted SRS resource can refer to the spatial relation information configured in the SRS resource, or can refer to the associated CSI-RS information configured in the SRS resource set including the SRS resource. The UE can transmit the SRS resource within the activated uplink BWP for the aperiodic SRS resource triggered through the DCI.

[0381] When a base station triggers aperiodic SRS transmission to a terminal through DCI, a minimum time interval may be required between a PDCCH including the DCI that triggers aperiodic SRS transmission and the SRS to be transmitted, so that the terminal can transmit the SRS by applying configuration information for the SRS resource. The time interval for SRS transmission of the terminal can be defined as the number of symbols between the last symbol of the PDCCH including the DCI that triggers aperiodic SRS transmission and the first symbol to which the first SRS resource to be transmitted among the SRS resource(s) is mapped. The minimum time interval can be determined with reference to the PUSCH preparation procedure time required for the terminal to prepare for PUSCH transmission. In addition, the minimum time interval can have different values ​​depending on the usage of the SRS resource set including the SRS resource to be transmitted. For example, the minimum time interval can be determined as N2 symbols, which are defined by considering the terminal processing ability according to the capability of the terminal with reference to the PUSCH preparation procedure time of the terminal. In addition, considering the usage of the SRS resource set including the SRS resource being transmitted, if the usage of the SRS resource set is set to 'codebook' or 'antennaSwitching', the minimum time interval can be set to N2 symbols, and if the usage of the SRS resource set is set to 'nonCodebook' or 'beamManagement', the minimum time interval can be set to N2+14 symbols.The terminal may transmit an aperiodic SRS if the time interval for aperiodic SRS transmission is greater than or equal to the minimum time interval, and may ignore the DCI that triggers the aperiodic SRS if the time interval for aperiodic SRS transmission is less than the minimum time interval.

[0382] [Table 24]

[0383]

[0384] The spatialRelationInfo setting information in [Table 24] above refers to a single reference signal and applies the beam information of the reference signal to the beam used for the corresponding SRS transmission. For example, the spatialRelationInfo setting may include information such as [Table 25] below.

[0385] [Table 25]

[0386]

[0387] Referring to the above spatialRelationInfo setting, the index of the reference signal to be referenced in order to use the beam information of a specific reference signal, i.e., the SS / PBCH block index, CSI-RS index, or SRS index can be set. The upper signaling referenceSignal is setting information indicating which beam information of which reference signal is to be referenced for the corresponding SRS transmission, ssb-Index means the index of the SS / PBCH block, csi-RS-Index means the index of the CSI-RS, and srs means the index of the SRS, respectively. If the value of the upper signaling referenceSignal is set to 'ssb-Index', the terminal can apply the reception beam used when receiving the SS / PBCH block corresponding to ssb-Index as the transmission beam of the corresponding SRS transmission. If the value of the upper signaling referenceSignal is set to 'csi-RS-Index', the terminal can apply the reception beam used when receiving the CSI-RS corresponding to csi-RS-Index as the transmission beam of the corresponding SRS transmission. If the value of the upper signaling referenceSignal is set to 'srs', the terminal can apply the transmission beam used when transmitting the SRS corresponding to srs as the transmission beam for the corresponding SRS transmission.

[0388] [SRS: Antenna switching]

[0389] Below, SRS for antenna switching is described.

[0390] The SRS transmitted from the terminal can be used by the base station to acquire DL CSI (Channel State Information) information (e.g., DL CSI acquisition). As a specific example, in a single cell or multi-cell (e.g., carrier aggregation (CA)) situation based on TDD (Time Division Duplex), the BS (Base Station) can schedule the transmission of SRS to the UE (User Equipment) and then measure the SRS transmitted from the UE. In this case, the base station can regard the uplink channel information estimated based on the SRS transmitted from the terminal as downlink channel information, assuming reciprocity between the DL (downlink) / UL (uplink) channels, and can perform downlink signal / channel scheduling for the terminal using this. In this case, the terminal can be configured to use antenna switching for the SRS for acquiring downlink channel information from the base station.

[0391] For example, according to the standard (e.g., 3gpp TS38.214), the usage of SRS can be set to the base station and / or terminal using a higher layer parameter (e.g., usage of RRC parameter SRS-ResourceSet). Here, the usage of SRS can be set to beam management usage, codebook transmission usage, non-codebook transmission usage, antenna switching usage, etc.

[0392] As described above, if the terminal receives the usage parameter in the upper layer signaling SRS-ResourceSet from the base station as 'antennaSwitching', the terminal can receive at least one upper layer signaling configuration from the base station according to the reported terminal capability. At this time, the terminal can report 'supportedSRS-TxPortSwitch' as ​​the terminal capability, and the value can be as follows. In the following, 'mTnR' can mean the terminal capability that supports transmission through m antennas and reception through n antennas.

[0393] - 't1r2': Terminal capability report value indicating that the terminal is capable of 1T2R operation.

[0394] - 't1r1-t1r2': Terminal capability report value indicating that the terminal is capable of 1T1R or 1T2R operation.

[0395] - 't2r4': Terminal capability report value indicating that the terminal is capable of 2T4R operation.

[0396] - 't1r4': Terminal capability report value indicating that the terminal is capable of 1T4R operation.

[0397] - 't1r6': Terminal capability report value indicating that the terminal is capable of 1T6R operation.

[0398] - 't1r8': Terminal capability report value indicating that the terminal is capable of 1T8R operation.

[0399] - 't2r6': Terminal capability report value indicating that the terminal is capable of 2T6R operation.

[0400] - 't2r8': Terminal capability report value indicating that the terminal is capable of 2T8R operation.

[0401] - 't4r8': Terminal capability report value indicating that the terminal is capable of 4T8R operation.

[0402] - 't1r1-t1r2-t1r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, or 1T4R operation.

[0403] - 't1r4-t2r4': Terminal capability report value indicating that the terminal is capable of 1T4R or 2T4R operation.

[0404] - 't1r1-t1r2-t2r2-t2r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, or 2T4R operation.

[0405] - 't1r1-t1r2-t2r2-t1r4-t2r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, 1T4R, or 2T4R operation.

[0406] - 't1r1': Terminal capability report value indicating that the terminal is capable of 1T1R operation.

[0407] - 't2r2': Terminal capability report value indicating that the terminal is capable of 2T2R operation.

[0408] - 't1r1-t2r2': Terminal capability report value indicating that the terminal is capable of 1T1R or 2T2R operation.

[0409] - 't4r4': Terminal capability report value indicating that the terminal is capable of 4T4R operation.

[0410] - 't1r1-t2r2-t4r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 2T2R, or 4T4R operation.

[0411] When a terminal performs antenna switching, i.e., transmits different SRS resources connected to different antenna ports, the time interval between two adjacent SRS resources among all transmitted SRS resources may typically require approximately 15 μs. Taking this into account, a (minimum) guard period can be defined, as shown in [Table 26] below.

[0412] [Table 26]

[0413]

[0414] In [Table 26], μ represents numerology, Δf represents subcarrier spacing, and Y may represent the number of OFDM symbols representing the guard interval, i.e., the length of the guard interval. Referring to [Table 26], the guard interval may be set based on the parameter μ that determines the numerology. In the guard interval, the terminal may be set not to transmit any other signals, and the guard interval may be set to be used entirely for antenna switching.

[0415] For example, the guard interval may be set between the transmission times of two adjacent SRS resources, taking into account SRS resources transmitted at different OFDM symbol locations within the same slot.

[0416] As another example, if a terminal is configured with two SRS resource sets for antenna switching purposes, and the two SRS resource sets are configured or triggered to be transmitted in two consecutive slots, and if the terminal reports the terminal capability to transmit SRS in all OFDM symbol positions within the slots, the terminal may expect that there will be a guard interval for antenna switching for at least Y OFDM symbols based on [Table 26] between the last OFDM symbol in which an SRS transmission is performed within the first slot in which an SRS transmission for the first SRS resource set is performed and the first OFDM symbol in which an SRS transmission is performed within the second slot in which an SRS transmission for the second SRS resource set is performed. That is, the time difference between two actual SRS transmissions may be greater than or equal to Y OFDM symbols.

[0417] - For such inter-slot guard intervals, similar to the guard interval between two SRS resources within the above-described slots, if the actual time difference between the last SRS transmission of the first slot and the first SRS transmission of the next slot within two consecutive slots is Y OFDM symbols, the terminal may not transmit any signal during the Y OFDM symbol interval.

[0418] - For such inter-slot guard intervals, if the actual time difference between the last SRS transmission of the first slot and the first SRS transmission of the next slot within two consecutive slots is Y OFDM symbols, and if all SRS transmissions before and after the inter-slot guard interval are dropped (cancelled) due to overlap with other signals, the terminal may determine that the inter-slot guard interval defined by Y OFDM symbols has been dropped (cancelled) by applying the same priority as the SRS transmissions before and after the guard interval, and if it is determined that it has been dropped, it may perform uplink transmission in this inter-slot guard interval.

[0419] For all antenna switching methods described above, the terminal can expect that all SRS resources within all SRS resource sets in which the upper layer signaling within the SRS resource set is set to 'antennaSwitching' from the base station will be configured with the same number of SRS ports.

[0420] For the antenna switching method based on the above-described 1T24, 1T4R, 2T4R, 1T6R, 1T8R, 2T6R, 2T8R, and 4T8R operations, the terminal may not expect that two or more SRS resource sets, of which the upper layer signaling usage from the base station is set to 'antennaSwitching', are set or triggered in the same slot.

[0421] For the antenna switching method based on the 1T1R, 2T2R, and 4T4R operations described above, the terminal may not expect that two or more SRS resource sets, in which the usage of the upper layer signaling from the base station is set to 'antennaSwitching', are set or triggered in the same OFDM symbol.

[0422] FIG. 11 is a diagram illustrating an SRS antenna switching operation according to one embodiment of the present disclosure.

[0423] The terminal represents a situation in which it operates in 1T4R, and may be configured with two aperiodic SRS resource sets (for example, SRS resource sets #0 and #1). The terminal receives a PDCCH from a base station (1100), and may be instructed to trigger aperiodic SRS for SRS resource set #0 (1110) and SRS resource set #1 (1120) through the PDCCH. At this time, the slot offset value for SRS resource set #0 (1110) may be configured as slotOffset, which is an upper layer signaling, and the value is 1, and aperiodic SRS transmission for SRS resource set #0 may be performed at a position 1 slot after the slot in which the PDCCH is received (i.e., at slot #1). Additionally, the slot offset value for SRS resource set #1 (1120) can be set to slotOffset, which is a higher layer signaling, and the value is 2, so that aperiodic SRS transmission for SRS resource set #1 can be performed at a position 2 slots after the slot in which the PDCCH is received (i.e., at slot #2).

[0424] SRS resource #0 (1111) and SRS resource #1 (1112) included in SRS resource set #0 (1110) are transmitted at different OFDM symbol positions within slot #1, and Y number of OFDM symbols may exist as a guard interval between SRS resources #0 and #1 (1113). In addition, when transmitting for SRS resource #0 (1130), the terminal can perform SRS transmission by connecting one SRS port to the first receiving antenna port (1135) of the terminal, and when transmitting for SRS resource #1 (1140), the terminal can perform SRS transmission by connecting one SRS port to the second receiving antenna port (1145) of the terminal.

[0425] SRS resource #2 (1121) and SRS resource #3 (1122) included in SRS resource set #1 (1120) are transmitted at different OFDM symbol positions within slot #1, and Y number of OFDM symbols may exist as a guard interval between SRS resources #2 and #3 (1123). In addition, when transmitting for SRS resource #2 (1150), the terminal can perform SRS transmission by connecting one SRS port to the third receiving antenna port (1155) of the terminal, and when transmitting for SRS resource #3 (1160), the terminal can perform SRS transmission by connecting one SRS port to the fourth receiving antenna port (1165) of the terminal.

[0426] By connecting the above-described four SRS resources #0 to #3 to different receiving antenna ports of terminals and transmitting SRS, the terminal can transmit SRS from all different receiving antenna ports so as to obtain channel information connected to all receiving antennas of the terminal, and through this, the base station can obtain channel information between the base station and the terminal and utilize it for uplink or downlink scheduling.

[0427] [Regarding terminal capability reporting]

[0428] In LTE and NR, a terminal, while connected to a serving base station, can perform a procedure to report its supported capabilities to the base station. In the description below, this is referred to as a UE capability report.

[0429] A base station can transmit a UE capability inquiry message requesting a capability report to a connected terminal. The message can include a UE capability request for each RAT (radio access technology) type of the base station. The RAT type-specific request can include information on a combination of supported frequency bands, etc. In addition, in the case of the UE capability inquiry message, UE capabilities for multiple RAT types can be requested through a single RRC message container transmitted by the base station, or the base station can include multiple UE capability inquiry messages including UE capability requests for each RAT type and transmit them to the terminal. That is, the UE capability inquiry can be repeated multiple times in one message, and the terminal can compose a corresponding UE capability information message and report it multiple times. In the next-generation mobile communication system, a UE capability request can be made for MR-DC (Multi-RAT dual connectivity), including NR, LTE, and EN-DC (E-UTRA - NR dual connectivity). Additionally, the terminal capability inquiry message is typically transmitted initially after the terminal is connected to the base station, but the base station may request it under any conditions when necessary.

[0430] In the above step, the terminal that receives the UE capability report request from the base station configures the terminal capability based on the RAT type and band information requested from the base station. Below is a summary of how the terminal configures the UE capability in the NR system.

[0431] 1. If the UE receives a list of LTE and / or NR bands through a UE capability request from the base station, the UE configures a band combination (BC) for EN-DC and NR stand-alone (SA). That is, it configures a candidate list of BCs for EN-DC and NR SA based on the bands requested to the base station via FreqBandList. Furthermore, the bands are prioritized in the order listed in FreqBandList.

[0432] 2. If the base station requests UE capability reporting by setting the "eutra-nr-only" flag or the "eutra" flag, the UE completely removes NR SA BCs from the list of configured BC candidates. This operation can only occur when the LTE base station (eNB) requests the "eutra" capability.

[0433] 3. The terminal then removes fallback BCs from the BC candidate list constructed in the above step. Here, a fallback BC is a BC obtained by removing at least one band corresponding to an SCell from a random BC. This step can be omitted because the BC before removing the band corresponding to at least one SCell can already cover the fallback BC. This step also applies to MR-DC, i.e., to LTE bands. The BCs remaining after this step are the final "candidate BC list."

[0434] 4. The terminal selects BCs to report by selecting BCs that match the requested RAT type from the final "candidate BC list" above. In this step, the terminal constructs the supportedBandCombinationList in a set order. That is, the terminal constructs BCs and UE capabilities to report in the order of the preset rat-Type (nr -> eutra-nr -> eutra). In addition, it constructs a featureSetCombination for the constructed supportedBandCombinationList, and constructs a list of "candidate feature set combinations" from the candidate BC list after removing the list for the fallback BC (which contains capabilities of the same or lower level). The "candidate feature set combinations" above include feature set combinations for both NR and EUTRA-NR BCs, and can be obtained from the feature set combinations in the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0435] 5. Also, if the requested rat Type is eutra-nr and has an effect, featureSetCombinations are included in both containers: UE-MRDC-Capabilities and UE-NR-Capabilities. However, the NR feature set is included only in UE-NR-Capabilities.

[0436] After terminal capabilities are configured, the terminal transmits a terminal capability information message containing the terminal capabilities to the base station. Based on the terminal capabilities received from the terminal, the base station then performs appropriate scheduling and transmission / reception management for the terminal.

[0437] [NC-JT related]

[0438] According to one embodiment of the present disclosure, Non-Coherent Joint Transmission (NC-JT) may be used for a terminal to receive PDSCH from multiple TRPs.

[0439] Unlike existing systems, 5G wireless communication systems can support not only services requiring high transmission speeds, but also services with very short transmission delays and high connection density. In a wireless communication network comprising multiple cells, transmission and reception points (TRPs), or beams, coordinated transmission between each cell, TRP, or / and beam can increase the signal strength received by a terminal or efficiently control interference between each cell, TRP, or / and beam, thereby satisfying diverse service requirements.

[0440] Joint Transmission (JT) is a representative transmission technology for the aforementioned cooperative communication, which increases the signal strength or processing rate received by a terminal by transmitting a signal to a single terminal through a number of different cells, TRPs, or / and beams. At this time, the channel between each cell, TRP, or / and beam and the terminal may have significantly different characteristics, and in particular, in the case of Non-Coherent Joint Transmission (NC-JT) that supports non-coherent precoding between each cell, TRP, or / and beam, individual precoding, MCS, resource allocation, TCI indication, etc. may be required depending on the channel characteristics of each link between each cell, TRP, or / and beam and the terminal.

[0441] The above-described NC-JT transmission can be applied to at least one channel among the downlink data channel (PDSCH), downlink control channel (PDCCH), uplink data channel (PUSCH), and uplink control channel (PUCCH). When transmitting PDSCH, transmission information such as precoding, MCS, resource allocation, and TCI are indicated as DL DCI, and for NC-JT transmission, the transmission information must be independently indicated for each cell, TRP, or / and beam. This is a major factor that increases the payload required for DL ​​DCI transmission, and this may adversely affect the reception performance of the PDCCH transmitting the DCI. Therefore, in order to support JT of PDSCH, it is necessary to carefully design a tradeoff between the amount of DCI information and the reception performance of control information.

[0442] FIG. 12 is a diagram illustrating an example of an antenna port configuration and resource allocation for transmitting a PDSCH using cooperative communication in a wireless communication system according to one embodiment of the present disclosure.

[0443] Referring to FIG. 12, examples for PDSCH transmission are explained for each technique of joint transmission (JT), and examples for allocating radio resources for each TRP are shown.

[0444] Referring to FIG. 12, an example (1200) for coherent joint transmission (C-JT) supporting coherent precoding between each cell, TRP or / and beam is illustrated.

[0445] In the case of C-JT, TRP A (1205) and TRP B (1210) transmit a single data (PDSCH) to the terminal (1215), and joint precoding can be performed on multiple TRPs. This may mean that DMRS is transmitted through the same DMRS ports for TRP A (1205) and TRP B (1210) to transmit the same PDSCH. For example, TRP A (1205) and TRP B (1210) may each transmit DRMS ​​to the terminal through DMRS port A and DMRS B. In this case, the terminal may receive one DCI information for receiving one PDSCH that is demodulated based on the DMRS transmitted through DMRS port A and DMRS B.

[0446] FIG. 12 illustrates an example (1220) of Non-Coherent Joint Transmission (NC-JT) supporting non-coherent precoding between each cell, TRP, or / and beam for PDSCH transmission.

[0447] In the case of NC-JT, PDSCH is transmitted to the terminal (1235) for each cell, TRP or / and beam, and individual precoding can be applied to each PDSCH. Each cell, TRP or / and beam transmits a different PDSCH or a different PDSCH layer to the terminal, thereby improving the throughput compared to single cell, TRP or / and beam transmission. In addition, each cell, TRP or / and beam repeatedly transmits the same PDSCH to the terminal, thereby improving the reliability compared to single cell, TRP or / and beam transmission. For convenience of explanation, cells, TRPs or / and beams are collectively referred to as TRPs hereinafter.

[0448] At this time, various wireless resource allocations can be considered, such as when the frequency and time resources used by multiple TRPs for PDSCH transmission are all the same (1240), when the frequency and time resources used by multiple TRPs do not overlap at all (1245), and when some of the frequency and time resources used by multiple TRPs overlap (1250).

[0449] To support NC-JT, DCIs of various forms, structures, and relationships can be considered to simultaneously allocate multiple PDSCHs to a single terminal.

[0450] FIG. 13 is a diagram illustrating an example of a configuration of downlink control information (DCI) for NC-JT in which each TRP transmits a different PDSCH or a different PDSCH layer to a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0451] Referring to FIG. 13, case #1 (1300) is an example in which, in addition to the serving TRP (TRP#0) used for single PDSCH transmission, (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)), and control information for PDSCHs transmitted from the (N-1) additional TRPs is transmitted independently from the control information for the PDSCHs transmitted from the serving TRP. That is, the terminal can obtain control information for PDSCHs transmitted from different TRPs (TRP#0 to TRP#(N-1)) through independent DCIs (DCI#0 to DCI#(N-1)). The formats between the independent DCIs may be the same or different, and the payloads between the DCIs may also be the same or different. In the aforementioned case #1, each PDSCH control or allocation freedom can be fully guaranteed, but if each DCI is transmitted in different TRPs, coverage differences may occur for each DCI, which may deteriorate reception performance.

[0452] Case #2 (1305) shows an example in which, in addition to the serving TRP (TRP#0) used for single PDSCH transmission, (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)), control information (DCI) for the PDSCHs of the (N-1) additional TRPs is transmitted respectively, and each of these DCIs is dependent on the control information for the PDSCH transmitted from the serving TRP.

[0453] For example, in the case of DCI#0, which is control information for a PDSCH transmitted from a serving TRP (TRP#0), it includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2, but in the case of shortened DCI (hereinafter, sDCI) (sDCI#0 to sDCI#(N-2)), which is control information for PDSCHs transmitted from cooperative TRPs (TRP#1 to TRP#(N-1)), it may include only some of the information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2. Therefore, in the case of sDCI, which transmits control information for PDSCHs transmitted from cooperative TRPs, since the payload is smaller than that of normal DCI (nDCI), which transmits PDSCH-related control information transmitted from a serving TRP, it is possible to include reserved bits compared to nDCI.

[0454] In the aforementioned case #2, the degree of freedom in controlling or allocating each PDSCH may be limited depending on the content of the information elements included in sDCI, but since the reception performance of sDCI is superior to that of nDCI, the probability of a difference in coverage by DCI may be reduced.

[0455] Case #3 (1310) shows an example in which, in a situation in which (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) other than the serving TRP (TRP#0) used for single PDSCH transmission, one control information for the PDSCHs of the (N-1) additional TRPs is transmitted, and this DCI is dependent on the control information for the PDSCH transmitted from the serving TRP.

[0456] For example, in the case of DCI#0, which is control information for PDSCH transmitted from a serving TRP (TRP#0), it includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2, and in the case of control information for PDSCHs transmitted from cooperative TRPs (TRP#1 to TRP#(N-1)), it is possible to collect only some of the information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2 into one 'secondary' DCI (sDCI) and transmit them. For example, the sDCI may include at least one piece of information among HARQ-related information such as frequency domain resource assignment, time domain resource assignment, and MCS of cooperative TRPs. In addition, for information not included in sDCI, such as BWP (bandwidth part) indicator or carrier indicator, the DCI (DCI#0, normal DCI, nDCI) of serving TRP can be followed.

[0457] Case #3 (1310) may limit the degree of freedom in controlling or allocating each PDSCH depending on the content of the information element included in sDCI, but it is possible to control the reception performance of sDCI and the complexity of blind decoding of DCI of the terminal may be reduced compared to case #1 (1300) or case #2 (1305).

[0458] Case #4 (1315) is an example of transmitting control information for PDSCHs transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in the same DCI (Long DCI) as the control information for PDSCHs transmitted from the serving TRP in a situation where (N-1) different PDSCHs are transmitted from (N-1) additional TRPs in addition to the serving TRP (TRP#0) used for single PDSCH transmission. That is, the UE can obtain control information for PDSCHs transmitted from different TRPs (TRP#0 to TRP#(N-1)) through a single DCI. In case #4 (1315), the complexity of DCI blind decoding of the UE may not increase, but the degree of freedom in PDSCH control or allocation may be low, such as because the number of cooperative TRPs is limited due to the long DCI payload limitation.

[0459] In the following descriptions and examples, sDCI may refer to various auxiliary DCIs, such as shortened DCI, secondary DCI, or normal DCI (DCI format 1_0 to 1_1 described above) containing PDSCH control information transmitted in a cooperative TRP, and unless a special limitation is specified, the description can be similarly applied to the various auxiliary DCIs described above.

[0460] In the following description and examples, the aforementioned cases #1 (1300), #2 (1305), and #3 (1310), in which more than one DCI (PDCCH) is used to support NC-JT, may be classified as multiple PDCCH-based NC-JT, and the aforementioned case #4 (1315), in which a single DCI (PDCCH) is used to support NC-JT, may be classified as single PDCCH-based NC-JT. In PDSCH transmission based on multiple PDCCH, a CORESET in which the DCI of the serving TRP (TRP#0) is scheduled and a CORESET in which the DCI of the cooperating TRPs (TRP#1 to TRP#(N-1)) are scheduled may be distinguished. As a method for distinguishing the CORESETs, there may be a method for distinguishing through an upper layer indicator for each CORESET, a method for distinguishing through beam setting for each CORESET, etc. Additionally, in single PDCCH-based NC-JT, instead of a single DCI scheduling multiple PDSCHs, a single PDSCH with multiple layers is scheduled, and the multiple layers described above can be transmitted from multiple Transmission Relays (TRPs). In this case, the connection relationship between a layer and the TRP transmitting the layer can be indicated through a Transmission Configuration Indicator (TCI) indication for the layer.

[0461] In the embodiments of the present disclosure, “cooperative TRP” may be replaced with various terms such as “cooperative panel” or “cooperative beam” in actual application.

[0462] In the embodiments of the present disclosure, “when NC-JT is applied” can be interpreted in various ways depending on the situation, such as “when a terminal simultaneously receives one or more PDSCHs in one BWP,” “when a terminal simultaneously receives PDSCHs based on two or more TCI (Transmission Configuration Indicator) indications in one BWP,” or “when a PDSCH received by a terminal is associated with one or more DMRS port groups,” but is used as a single expression for convenience of explanation.

[0463] The wireless protocol architecture for NC-JT in the present disclosure can be used in various ways depending on the TRP deployment scenario. For example, when there is no or small backhaul delay between cooperative TRPs, a method using a structure based on MAC layer multiplexing (CA-like method) similar to S10 of FIG. 4 is possible. On the other hand, when the backhaul delay between cooperative TRPs is so large that it cannot be ignored (for example, when it takes more than 2 ms to exchange information such as CSI, scheduling, and HARQ-ACK between cooperative TRPs), a method (DC-like method) is possible to secure delay-robust characteristics by using an independent structure for each TRP starting from the RLC layer, similar to S20 of FIG. 4.

[0464] A terminal supporting C-JT or / and NC-JT can receive C-JT or / and NC-JT related parameters or setting values ​​from a higher layer configuration, and set the RRC parameters of the terminal based on the parameters. For the higher layer configuration, the terminal can utilize a UE capability parameter, for example, tci-StatePDSCH. Here, the UE capability parameter, for example, tci-StatePDSCH, can define TCI states for the purpose of PDSCH transmission, and the number of TCI states can be set to 4, 8, 16, 32, 64, 128 in FR1, and to 64 and 128 in FR2, and among the set number, up to 8 states can be set that can be indicated by 3 bits of the TCI field of the DCI via a MAC CE message. The maximum value 128 means the value indicated by maxNumberConfiguredTCIstatesPerCC in the tci-StatePDSCH parameter included in the capability signaling of the terminal. In this way, a series of configuration processes from upper layer configuration to MAC CE configuration can be applied to a beamforming instruction or beamforming change command for at least one PDSCH in one TRP.

[0465] [Multi-DCI based Multi-TRP]

[0466] As one embodiment of the present disclosure, a multi-DCI-based multi-TRP transmission method is described. The multi-DCI-based multi-TRP transmission method can establish a downlink control channel for NC-JT transmission based on a multi-PDCCH.

[0467] In NC-JT based on multiple PDCCHs, when transmitting DCI for the PDSCH schedule of each TRP, a CORESET or search space can be distinguished for each TRP. The CORESET or search space for each TRP can be configured as in at least one of the following cases.

[0468] * Setting of upper layer index for each CORESET: The CORESET setting information set as an upper layer may include an index value, and the TRP transmitting the PDCCH in the corresponding CORESET may be distinguished by the set index value for each CORESET. That is, in a set of CORESETs with the same upper layer index value, it may be considered that the same TRP transmits the PDCCH, or it may be considered that a PDCCH scheduling the PDSCH of the same TRP is transmitted. The above-described index for each CORESET may be named as CORESETPoolIndex, and for CORESETs with the same CORESETPoolIndex value set, it may be considered that the PDCCH is transmitted from the same TRP. For a CORESET for which the CORESETPoolIndex value is not set, it may be considered that the default value of CORESETPoolIndex is set, and the above-described default value may be 0.

[0469] ** In the present disclosure, if the number of types of CORESETPoolIndex of each of the multiple CORESETs included in the upper layer signaling PDCCH-Config exceeds 1, i.e., if each CORESET has a different CORESETPoolIndex, the terminal may consider that the base station can use the multi-DCI based multi-TRP transmission method.

[0470] ** Differently, in the present disclosure, if each of the multiple CORESETs included in the upper layer signaling PDCCH-Config has only one type of CORESETPoolIndex, that is, if all CORESETs have the same CORESETPoolIndex of 0 or 1, the terminal can assume that the base station transmits using a single-TRP rather than using a multi-DCI based multi-TRP transmission method.

[0471] * Multiple PDCCH-Config settings: Multiple PDCCH-Configs are configured within one BWP, and each PDCCH-Config can include PDCCH settings for each TRP. That is, a list of CORESETs for each TRP and / or a list of search spaces for each TRP can be configured in one PDCCH-Config, and one or more CORESETs and one or more search spaces included in one PDCCH-Config can be considered to correspond to a specific TRP.

[0472] * CORESET Beam / Beam Group Configuration: The TRP corresponding to the CORESET can be distinguished through the beam or beam group configured for each CORESET. For example, if the same TCI state is set for multiple CORESETs, the CORESETs can be considered to be transmitted through the same TRP, or the PDCCH that schedules the PDSCH of the same TRP can be considered to be transmitted in the CORESET.

[0473] * Search space beam / beam group configuration: A beam or beam group is configured for each search space, and this allows TRPs for each search space to be distinguished. For example, if the same beam / beam group or TCI state is set for multiple search spaces, it can be considered that the same TRP transmits a PDCCH in the corresponding search space, or that a PDCCH that schedules the PDSCH of the same TRP is transmitted in the corresponding search space.

[0474] By dividing the CORESET or search space by TRP as described above, PDSCH and HARQ-ACK information classification for each TRP is possible, and this enables independent HARQ-ACK codebook generation and independent PUCCH resource use for each TRP.

[0475] The above settings can be independent on a per-cell or per-BWP basis. For example, a PCell may have two different CORESETPoolIndex values ​​configured, while a specific SCell may not have a CORESETPoolIndex value configured. In this case, it can be assumed that NC-JT transmission is configured on the PCell, while NC-JT transmission is not configured on the SCell without the CORESETPoolIndex value configured.

[0476] Figure 10 illustrates a process for beam setting and activation of PDSCH.

[0477] The PDSCH TCI state activation / deactivation MAC-CE applicable to the multi-DCI based multi-TRP transmission method can follow Fig. 10. The base station can set M TCI states (TCI state #0, TCI state #1, ..., TCI state #M-1) to the terminal through upper layer signaling (1000). The base station can activate some of the M TCI states, for example, TCI state #0', TCI state #1', ..., TCI state #K-1, for the PDSCH through MAC CE signaling (1020). This can be called MAC CE based beam indication. The base station can indicate one TCI state (TCI state #I) among the activated TCI states, for example, TCI state #0', TCI state #1', ..., TCI state #K-1, through DCI (1040). This may be referred to as DCI-based beam selection. If the terminal does not set CORESETPoolIndex for each of the CORESETs in the upper layer signaling PDCCH-Config, the terminal may ignore the CORESET Pool ID field (1055) in the corresponding MAC-CE (1050).If the terminal can support the multi-DCI based multi-TRP transmission method, i.e., if each CORESET in the upper layer signaling PDCCH-Config of the terminal has a different CORESETPoolIndex, the terminal can activate the TCI state in the DCI included in the PDCCH transmitted from the CORESETs having the same CORESETPoolIndex value as the CORESET Pool ID field (1055) value in the corresponding MAC-CE (1050). For example, if the value of the CORESET Pool ID field (1055) in the corresponding MAC-CE (1050) is 0, the TCI state in the DCI included in the PDCCH transmitted from the CORESETs having CORESETPoolIndex of 0 can follow the activation information of the corresponding MAC-CE.

[0478] When a terminal is configured to use a multi-DCI based multi-TRP transmission method from a base station, that is, when each of multiple CORESETs included in the upper layer signaling PDCCH-Config has more than one type of CORESETPoolIndex or when each CORESET has a different CORESETPoolIndex, the terminal can know that the following restrictions exist for PDSCHs scheduled from PDCCHs within each CORESET having two different CORESETPoolIndexes.

[0479] 1) If the PDSCHs indicated by the PDCCHs within each CORESET having two different CORESETPoolIndexes completely or partially overlap, the TCI states indicated by each PDCCH can be applied to different CDM groups. That is, two or more TCI states may not be applied to a single CDM group.

[0480] 2) The terminal can expect that the actual number of front-loaded DMRS symbols, the actual number of additional DMRS symbols, the location of actual DMRS symbols, and the DMRS type of each PDSCH will not be different when the PDSCHs indicated from the PDCCHs within each CORESET having two different CORESETPoolIndexes overlap completely or partially.

[0481] 3) The terminal can expect that the bandwidth portion indicated by the PDCCH within each CORESET having two different CORESETPoolIndexes will be the same and that the subcarrier spacing will also be the same.

[0482] 4) The terminal can expect that each PDCCH will fully contain information about the PDSCH scheduled from the PDCCH within each CORESET having two different CORESETPoolIndexes.

[0483] [Single-DCI based Multi-TRP]

[0484] As one embodiment of the present disclosure, a single-DCI-based multi-TRP transmission method is described. The single-DCI-based multi-TRP transmission method can establish a downlink control channel for NC-JT transmission based on a single-PDCCH.

[0485] In a single DCI-based multi-TRP transmission method, a PDSCH transmitted by multiple TRPs can be scheduled with a single DCI. At this time, the number of TCI states can be used as a method of indicating the number of TRPs transmitting the corresponding PDSCH. That is, if the number of TCI states indicated in the DCI scheduling the PDSCH is two, it can be considered as a single PDCCH-based NC-JT transmission, and if the number of TCI states is one, it can be considered as a single-TRP transmission. The TCI states indicated in the above DCI can correspond to one or both of the TCI states activated by MAC-CE. When the TCI states of the DCI correspond to two TCI states activated by MAC-CE, a correspondence relationship is established between the TCI codepoint indicated in the DCI and the TCI states activated by MAC-CE, and this can be the case when there are two TCI states activated by MAC-CE corresponding to the above TCI codepoint.

[0486] As another example, if at least one codepoint among all codepoints in the TCI state field within the DCI indicates two TCI states, the UE may assume that the base station can transmit based on the single-DCI based multi-TRP method. In this case, at least one codepoint indicating two TCI states within the TCI state field may be activated via the Enhanced PDSCH TCI state activation / deactivation MAC-CE.

[0487] Figure 14 is a diagram illustrating the structure of the Enhanced PDSCH TCI state activation / deactivation MAC-CE. The meaning of each field within the MAC CE and the values ​​that can be set for each field are as shown in [Table 27] below.

[0488] [Table 27]

[0489]

[0490] In Fig. 14, if the value of the C0 field (1405) is 1, the corresponding MAC-CE is the TCI state ID 0,1 Additionally, TCI state ID in field (1410) 0,2 It may include field (1415). This is the TCI state ID for the 0th codepoint of the TCI state field included in the DCI. 0,1 and TCI state ID 0,2 This means that the MAC-CE is activated, and if the base station instructs the terminal with the corresponding codepoint, the terminal can be instructed with two TCI states. If the value of the C0 field (1405) is 0, the corresponding MAC-CE is the TCI state ID. 0,2 It cannot contain field (1415), which is the TCI state ID for the 0th codepoint of the TCI state field contained within the DCI. 0,1 This means that one TCI state corresponding to is activated.

[0491] The above configuration can be independent on a per-cell or per-BWP basis. For example, a PCell may have up to two activated TCI states corresponding to a single TCI codepoint, while a specific SCell may have up to one activated TCI state corresponding to a single TCI codepoint. In this case, it can be assumed that NC-JT transmission is configured on the PCell, while NC-JT transmission is not configured on the aforementioned SCell.

[0492] [Distinguishing between Single-DCI-based Multi-TRP PDSCH Repetitive Transmission Techniques (TDM / FDM / SDM)]

[0493] Next, we describe a method for distinguishing between single-DCI-based multi-TRP PDSCH repetition transmission techniques. A UE may be instructed to use different single-DCI-based multi-TRP PDSCH repetition transmission techniques (e.g., TDM, FDM, SDM) based on values ​​indicated by a DCI field from a base station and higher-layer signaling configurations. Table 28 below illustrates a method for distinguishing between single- and multiple-TRP-based techniques indicated to a UE based on values ​​of specific DCI fields and higher-layer signaling configurations.

[0494] [Table 28]

[0495]

[0496] In the above [Table 28], each column can be explained as follows.

[0497] - Number of TCI states (2 columns): This refers to the number of TCI states indicated by the TCI state field in DCI, and can be 1 or 2.

[0498] - Number of CDM Groups (column 3): This indicates the number of different CDM groups of DMRS ports indicated by the Antenna port field in the DCI. It can be 1, 2, or 3.

[0499] - repetitionNumber setting and indication conditions (column 4): There are three conditions depending on whether repetitionNumber is set for all TDRA entries that can be indicated by the Time Domain Resource Allocation field in DCI and whether the actually indicated TDRA entry has repetitionNumber setting.

[0500] * Condition 1: At least one of all TDRA entries that can be indicated by the Time Domain Resource Allocation field contains a setting for repetitionNumber, and the TDRA entry indicated by the Time Domain Resource Allocation field in the DCI contains a setting for repetitionNumber greater than 1.

[0501] * Condition 2: At least one of all TDRA entries that can be indicated by the Time Domain Resource Allocation field contains a setting for repetitionNumber, and the TDRA entry indicated by the Time Domain Resource Allocation field in the DCI does not contain a setting for repetitionNumber.

[0502] * Condition 3: If all TDRA entries that can be indicated by the Time Domain Resource Allocation field do not contain a setting for repetitionNumber.

[0503] - RepetitionScheme setting related (column 5): This indicates whether the upper layer signaling repetitionScheme is set. The upper layer signaling repetitionScheme can be set to one of 'tdmSchemeA', 'fdmSchemeA', or 'fdmSchemeB'.

[0504] - Transmission technique indicated to the terminal (column 6): Refers to single or multiple TRP techniques indicated according to each combination (column 1) expressed in [Table 28] above.

[0505] * Single-TRP: This refers to a single TRP-based PDSCH transmission. If the UE has configured the pdsch-AggegationFactor in the upper layer signaling PDSCH-config, the UE can be scheduled for the configured number of repeated single-TRP-based PDSCH transmissions. Otherwise, the UE can be scheduled for a single single-TRP-based PDSCH transmission.

[0506] * Single-TRP TDM scheme B: This refers to PDSCH repeated transmission based on time resource division between single TRP slots. According to Condition 1 related to repetitionNumber described above, the UE repeatedly transmits PDSCH in the time dimension for the number of slots with repetitionNumber that is greater than 1 set in the TDRA entry indicated by the Time Domain Resource Allocation field. At this time, for each slot equal to the repetitionNumber number, the start symbol and symbol length of the PDSCH indicated by the TDRA entry are applied identically, and the same TCI state is applied for each PDSCH repeated transmission. This technique is similar to the slot aggregation method in that it performs PDSCH repeated transmission between slots on time resources, but it differs from slot aggregation in that it can dynamically determine whether to indicate repeated transmission based on the Time Domain Resource Allocation field in the DCI.

[0507] * Multi-TRP SDM: This refers to a PDSCH transmission method based on spatial resource division based on multiple TRPs. This is a method of receiving by dividing layers from each TRP. Although it is not a repetitive transmission method, it can increase the reliability of PDSCH transmission by increasing the number of layers and lowering the coding rate. The terminal can receive PDSCH by applying the two TCI states indicated through the TCI state field in the DCI for each of the two CDM groups indicated by the base station.

[0508] * Multi-TRP FDM scheme A: This refers to a multi-TRP based frequency resource division PDSCH transmission method. It has one PDSCH transmission position (occasion), so it is not repetitive transmission like multi-TRP SDM, but it is a technique that can transmit with high reliability by increasing the frequency resource amount and lowering the coding rate. Multi-TRP FDM scheme A can apply two TCI states indicated through the TCI state field in the DCI for non-overlapping frequency resources. If the PRB bundling size is determined as wideband, if the number of RBs indicated by the Frequency Domain Resource Allocation field is N, the terminal applies the first TCI state to the first ceil(N / 2) RBs and applies the second TCI state to the remaining floor(N / 2) RBs. Here, ceil(.) and floor(.) are operators that indicate rounding up and down to the first decimal place. If the PRB bundling size is determined as 2 or 4, even-numbered PRGs receive the first TCI state, and odd-numbered PRGs receive the second TCI state.

[0509] * Multi-TRP FDM scheme B: This refers to a multi-TRP based frequency resource division PDSCH repeated transmission method, and it has two PDSCH transmission positions (occasions) so that PDSCH can be repeatedly transmitted in each position. Multi-TRP FDM scheme B, like A, can apply two TCI states indicated through the TCI state field in the DCI to non-overlapping frequency resources. If the PRB bundling size is determined as wideband, if the number of RBs indicated by the Frequency Domain Resource Allocation field is N, the UE applies the first TCI state to the first ceil (N / 2) RBs and applies the second TCI state to the remaining floor (N / 2) RBs and receives them. Here, ceil (.) and floor (.) are operators indicating round up and down to the first decimal place. If the PRB bundling size is determined as 2 or 4, even-numbered PRGs receive the first TCI state, and odd-numbered PRGs receive the second TCI state.

[0510] * Multi-TRP TDM scheme A: This refers to a PDSCH repeated transmission method within a multi-TRP based time resource division slot. A terminal has two PDSCH transmission positions (occasions) within one slot, and the first reception position can be determined based on the starting symbol and symbol length of the PDSCH indicated through the Time Domain Resource Allocation field in the DCI. The starting symbol of the second reception position of the PDSCH can be a position that applies a symbol offset by the upper layer signaling StartingSymbolOffsetK from the last symbol of the first transmission position, and the transmission position can be determined by the indicated symbol length. If the upper layer signaling StartingSymbolOffsetK is not set, the symbol offset can be regarded as 0.

[0511] * Multi-TRP TDM scheme B: This refers to a PDSCH repeated transmission method between time resource division slots based on multiple TRPs. The UE has one PDSCH transmission position (occasion) in one slot, and can receive repeated transmissions based on the start symbol and symbol length of the same PDSCH for the number of slots indicated by the repetitionNumber through the Time Domain Resource Allocation field in the DCI. If the repetitionNumber is 2, the UE can receive the PDSCH repeated transmissions of the first and second slots by applying the first and second TCI states, respectively. If the repetitionNumber is greater than 2, the UE can use different TCI state application methods depending on how the upper layer signaling tciMapping is set. If tciMapping is set to cyclicMapping, the first and second TCI states are applied to the first and second PDSCH transmission positions, respectively, and the same TCI state application method is applied to the remaining PDSCH transmission positions. If tciMapping is set to sequentialMapping, the first TCI state is applied to the first and second PDSCH transmission positions, the second TCI state is applied to the third and fourth PDSCH transmission positions, and the same TCI state application method is applied to the remaining PDSCH transmission positions.

[0512] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. The contents of the present disclosure can be applied to FDD (frequency division duplex), TDD (time division duplex) and / or XDD (cross division duplex) (and / or SBFD (subband non-overlapping full duplex), full duplex) systems. In the present disclosure below, upper signaling (or upper layer signaling) refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer, and may also be referred to as RRC signaling, PDCP signaling, or MAC (medium access control) control element (MAC control element; MAC CE).

[0513] For convenience in the following description of the present disclosure, cells, transmission points, panels, beams, and / or transmission directions, which can be distinguished through upper layer / L1 parameters such as TCI state or spatial relation information, or indicators such as cell ID, TRP ID, and panel ID, may be uniformly described as TRP (transmission reception point), beam, or TCI state. Therefore, in actual application, TRP, beam, or TCI state can be appropriately replaced with one of the above terms.

[0514] In the present disclosure, when determining whether cooperative communication is applied, the terminal may use various methods, such as having the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied have a specific format, or including a specific indicator that indicates whether cooperative communication is applied, or scrambled with a specific RNTI by the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied, or assuming cooperative communication is applied in a specific section indicated by a higher layer. For the convenience of the following description, the case where the terminal receives the PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as the NC-JT case.

[0515] Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Although the embodiments of the present disclosure are described below using a 5G system as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, this may include LTE or LTE-A mobile communication and mobile communication technologies developed after 5G. Therefore, the 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 determined by a person skilled in the art.

[0516] Additionally, when describing the present disclosure, detailed descriptions of related functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the contents of this specification.

[0517] In the following description of the present disclosure, upper layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

[0518] - MIB (Master Information Block)

[0519] - SIB (System Information Block) or SIB

[0520] - RRC (Radio Resource Control)

[0521] - MAC (Medium Access Control) CE (Control Element)

[0522] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using the physical layer channel or signaling below.

[0523] - PDCCH (Physical Downlink Control Channel)

[0524] - DCI (Downlink Control Information)

[0525] - UE-specific DCI

[0526] - Group common DCI

[0527] - Common DCI

[0528] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0529] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0530] - PUCCH (Physical Uplink Control Channel)

[0531] - UCI (Uplink Control Information)

[0532] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

[0533] The term slot used in the present disclosure below is a general term that may refer to a specific time unit corresponding to a TTI (Transmit Time Interval), and may specifically mean a slot used in a 5G NR system, or a slot or subframe used in a 4G LTE system.

[0534] In the present disclosure below, the above examples are described through a number of embodiments, but they are not independent and one or more embodiments may be applied simultaneously or in combination.

[0535] As one embodiment of the present disclosure, a process for a base station to obtain a CSI report transmitted by a terminal to the base station is described. This embodiment can be operated in combination with other embodiments.

[0536] In order to flexibly and efficiently perform control and scheduling for multiple cells, a base station may be configured with a structure in which multiple RUs (Radio Units) or multiple MMUs (Massive MIMO Units) are connected to a single DU (Distributed Unit). In this case, a single DU may perform scheduling for transmitting DL signals and channels to a terminal through multiple RUs or multiple MMUs, and conversely, multiple RUs or multiple MMUs may receive UL signals and channels transmitted from a terminal and process them in a single DU. Hereinafter, MMU or RU may be used with the same meaning as TRP. In the description of the present disclosure, MMU, RU, and TRP may be used interchangeably / replaced. In the description of the present disclosure, the operations of the MMU, RU, and DU may also be understood as the operations of a base station including the MMU, RU, and DU. It may be an operation based on each MMU, RU, and DU of a base station including the MMU, RU, and DU.

[0537] FIG. 15 is a diagram illustrating elements of a base station according to one embodiment of the present disclosure, and a process by which the base station acquires channel state information of a terminal through CSI transmitted by the terminal. FIG. 15 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in FIG. 15 . For example, although illustrated as a series of steps, the various steps in each diagram may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0538] For example, a base station may be composed of one DU (1500) and two MMUs (e.g., a first MMU (1505) (MMU#1) and a second MMU (1510) (MMU#2)). One DU and one MMU may be connected to each other via a fronthaul (FH: FrontHaul) (1515).

[0539] The terminal (1520) may transmit the CSI report to a specific MMU for transmission to the base station, or may transmit it commonly to all MMUs. The terminal (1520) may transmit the CSI report to either the first MMU (1505) or the second MMU (1510). Alternatively, the terminal (1520) may transmit the CSI report to the first MMU (1505) and the second MMU (1510). In this case, the base station, which is composed of one DU connected to multiple MMUs, may receive the CSI report transmitted by the terminal and perform scheduling for the terminal based on the CSI report. That is, the CSI transmitted by the terminal is decoded in the DU, so that the base station can confirm the information, and by decoding the CSI reported by multiple terminals in this way, the DU can determine how to allocate each terminal to which time and frequency resource. Multiple CSIs received from multiple terminals are decoded in the DU, and the DU (base station) can perform time / frequency resource scheduling for the multiple terminals based on the decoding results. A more specific process for this can be described as follows. In the following description, the MMU can be at least one of the first MMU (1505) or the second MMU (1510).

[0540] At step (1550), the terminal may transmit a CSI report to the MMU. The CSI report may be transmitted within a PUCCH or PUSCH.

[0541] In step (1555), the MMU may transmit information about the PUCCH or PUSCH including the CSI report of the corresponding terminal to the DU through the fronthaul, and this information may be transmitted through the user plane, which is an interface within the fronthaul, and at this time, the real or imaginary data of the PUCCH or PUSCH may be quantized into a specific number of bits and transmitted. The number of bits that may be considered at this time may be 9, 11, or 16 bits for each of the real and imaginary parts. The real and / or imaginary parts of the PUCCH and / or PUSCH may be quantized into 9 bits, 11 bits, or 16 bits and transmitted.

[0542] In step (1560), a DU that has received information on a PUCCH or PUSCH including CSI of a terminal can decode the CSI included in the PUCCH or PUSCH to determine / identify the CSI information reported by the terminal.

[0543] At step (1565), the DU may determine scheduling for the corresponding terminal based on the CSI information. At this time, scheduling for the corresponding terminal may be in the form of Single-User Multiple-Input Multiple-Output (SU-MIMO), which allocates only the corresponding terminal to specific time and frequency resources, or in the form of Multi-User Multiple-Input Multiple-Output (MU-MIMO), which allocates the corresponding terminal and other terminals together to the same time and frequency resources.

[0544] At step (1570), the DU may transmit the scheduling information to the MMU. The information included here may include time and frequency resource allocation information, information related to the precoder to be used by the terminal, and the MCS level. Information related to the precoder to be used by the terminal may include, when using a predefined PMI, which PMI to use, what the rank value is, and, when using an SRS-based precoder, how to process / encode the channel estimated through the SRS.

[0545] In step (1575), the MMU may generate and apply a downlink precoder to be applied to the corresponding terminal based on the scheduling information received from the DU. The MMU may store the entire set of PMIs in case it receives information from the DU regarding application of a PMI-based downlink precoder. The entire set of PMIs may be preset in the MMU. Operations related to application of a PMI-based downlink precoder may be performed based on the entire set of PMIs. Accordingly, if the scheduling information received from the DU includes information indicating that a PMI is to be used as a downlink precoder to be applied to a specific terminal, the MMU may select the specific PMI indicated by the DU from the entire set of PMIs stored in the MMU as the downlink precoder to be applied to the terminal. The DU may instruct the MMU to use a specific PMI, to generate a specific precoder through a linear combination of one or more PMIs, or to use each element of the specific PMI with some modifications. Additionally, the DU may instruct the MMU to update the entire set of PMIs, after which the DU and MMU may exchange instructions for the use of specific PMIs, assuming a different set of PMIs than before the update. The entire set of PMIs may change before and after the update. After the update, instructions for the use of specific PMIs within the updated set of PMIs may be exchanged.

[0546] At step (1580), the MMU may transmit a PDSCH to the terminal by applying the downlink precoder. The MMU may transmit scheduling information for the PDSCH. Additionally, the MMU may transmit the PDSCH to the terminal. At this time, the terminal may be scheduled in the form of SU-MIMO or MU-MIMO, as described above.

[0547] In the case where the above process is performed, when the terminal is scheduled to receive PDSCH from the base station (1580), the precoder applied to the corresponding PDSCH may be based on information of CSI previously reported by the terminal. Applying the precoder to the PDSCH may be performed based on information of CSI previously reported by the terminal. For convenience of explanation, the time points at which the terminal reports CSI and the time points at which the terminal receives the PDSCH are referred to as T1 and T2, respectively. If the time interval between T1 and T2 is large (for example, when the time interval is equal to or greater than a certain threshold), the downlink precoder applied to the PDSCH transmitted to the terminal is reported at time point T1, which may be a time point much earlier than T2, which is the time point at which the downlink precoder is actually applied, and therefore, a downlink precoder that does not match the channel between the base station and the terminal at time point T2 may be applied.

[0548] The primary reason this situation occurs is because the CSI reported by the terminal is verified by the DU and can be used for scheduling. Potential deterioration factors that may arise during this process include:

[0549] - (Fronthaul Quantization) The CSI reported by the terminal is transmitted to the MMU via the PUCCH or PUSCH, and the MMU receives it and sends it to the fronthaul, where it undergoes a quantization process as described above. At this time, quantization errors may occur in the real and / or imaginary symbols of the PUCCH and / or PUSCH, which may affect subsequent decoding in the DU.

[0550] - (Fronthaul Delay) CSI reported by the terminal is transmitted from the MMU to the DU via the fronthaul. Depending on the information being transmitted through the fronthaul, the transmission of the corresponding PUCCH or PUSCH may be delayed. This may delay the start of CSI decoding in the DU.

[0551] - (DU Uplink Processing) CSI reported by a terminal may undergo a decoding process in the DU. At this time, the DU must process uplink data not only for the terminal in question but also for other terminals. Therefore, the more terminals requiring uplink data processing, the later the time it takes for the terminal to begin CSI decoding. Consequently, the later the time it takes for CSI decoding to be reflected in scheduling.

[0552] - (CSI applied to PDSCH is CSI used for scheduling) The DU performs scheduling based on the CSI reported by the UE, and the CSI used for scheduling can be directly applied to PDSCH transmission. Therefore, if there is a difference between the UE's CSI reporting time and the UE's PDSCH reception time, performance degradation may occur when the CSI reported by the UE is applied to PDSCH transmission. In addition, even if the UE performs CSI reporting not only for T1 but also for T1-1 and T1-2 before time T2 and the MMU receives it, since CSI decoding can occur in the DU, the base station cannot utilize the CSI reported for T1-1 (1551) and T1-2 (1552) to apply it to the PDSCH.

[0553] To more quickly utilize CSI reported by a terminal and apply it to the terminal's downlink signal, the base station can utilize a method in which the MMU decodes the CSI. If the MMU decodes the CSI reported by the terminal, the MMU can more quickly identify the terminal's CSI and use it for reception of the terminal's uplink channel / signal or transmission of the downlink channel / signal to the terminal.

[0554] - If a terminal transmits an uplink channel / signal, and if channel reciprocity of the uplink and downlink channels is established, the MMU can receive the uplink transmission of the terminal based on the PMI included in the CSI reported by the terminal. Since the PMI included in the CSI reported by the terminal is information that best represents the channel between the terminal and the base station when the terminal receives the downlink channel / signal, the information can be similarly applied to the reception of the uplink channel / signal using the channel between the same base station and terminal. If channel reciprocity of the uplink and downlink channels is established, the PMI included in the CSI reported by the terminal to the base station can also be applied to the uplink channel / signal between the same base station and terminal.

[0555] - When a terminal receives a downlink channel / signal, when the MMU determines a downlink precoder to be applied to the PDCCH or PDSCH to be transmitted to the terminal, if the MMU can decode the CSI reported by the terminal, the latest PMI that can be included in the CSI reported by the terminal may be one of the candidates for the downlink precoder to be ultimately determined. Through this, the terminal can expect that the most recently reported CSI that can better represent the current channel than the CSI reported at the previous point in time will be applied and received to the downlink channel / signal. That is, if the PDSCH reception time determined based on the CSI reported by the terminal at time T1 as described above is T2, and the terminal performs additional CSI reports at T1-1 (1551) and T1-2 (1552) between T1 and T2, and if the MMU can decode the corresponding CSI, the MMU can apply the PMI in the latest CSI reported by the terminal at time T1-2 (1552) when transmitting the PDSCH at time T2.

[0556] - If a terminal reports to the base station information that can compensate for time, frequency, and / or phase differences between different MMUs (information for compensating for time, frequency, and / or phase differences between different MMUs) (i.e., such CSI report may be of a different type from information such as PMI, RI, and CQI for channel state information of the terminal), an MMU without CSI decoding capability can transmit the information to the DU, which can receive it, decode the CSI information, and retransmit the necessary information to each MMU. Each MMU can perform the compensation based on the information that can compensate for time, frequency, and / or phase differences for each MMU retransmitted by the DU. If an MMU with CSI decoding capability is considered, the information that can compensate for time, frequency, and / or phase differences reported by the terminal can be decoded by the MMU and the corresponding value for each MMU can be compensated. The MMU can provide information to the DU so that the DU can know the status of this MMU (whether it has received information that can compensate for the time, frequency, and / or phase differences reported by the UE and / or has applied this information to compensate for the time, frequency, and / or phase differences compared to other MMUs). Based on the status of this MMU, the DU can schedule downlink data transmission to a specific UE in the form of coherent joint transmission (CJT).

[0557] In this case, when the MMU can decode CSI, the signaling exchange between the terminal, MMU, and DU and the scheduling process through CSI can be explained as follows.

[0558] FIG. 16 is another diagram illustrating an example of a process by which a base station acquires channel state information of a terminal through CSI transmitted by the terminal according to an embodiment of the present disclosure. FIG. 16 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in FIG. 16. For example, although illustrated as a series of steps, the various steps in each diagram may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps. In the following description, the MMU may be at least one of the first MMU (1605) or the second MMU (1610).

[0559] At step (1650), the terminal may transmit a CSI report to the MMU. The CSI report may be transmitted within a PUCCH or PUSCH.

[0560] At step (1655), the MMU can decode the CSI to obtain CSI information of the corresponding terminal. At this time, the MMU can perform decoding only for the CSI portion of the PUCCH or PUSCH.

[0561] In step (1660), when the MMU transmits CSI information to the DU thereafter, the MMU may transmit to the DU the CSI information decoded by the MMU and the non-CSI portion (the portion other than CSI) of the PUCCH or PUSCH. This information may be transmitted through the user plane, which is an interface within the fronthaul, and at this time, the real or imaginary data of the PUCCH or PUSCH may be quantized into a specific number of bits and transmitted. The number of bits that may be considered at this time may be 9, 11, or 16 bits for the real and imaginary portions, respectively. The real and / or imaginary portions of the PUCCH and / or PUSCH may be quantized into 9 bits, 11 bits, or 16 bits and transmitted.

[0562] At step (1665), the DU can determine scheduling for the corresponding terminal based on the CSI information decoded and transmitted from the MMU. At this time, scheduling for the corresponding terminal may be in the form of a Single-User Multiple-Input Multiple-Output (SU-MIMO) that allocates only the corresponding terminal to specific time and frequency resources, or in the form of a Multi-User Multiple-Input Multiple-Output (MU-MIMO) that allocates the corresponding terminal and other terminals together to the same time and frequency resources.

[0563] In step (1670), the DU may transmit the scheduling information to the MMU. The information included at this time may include time and frequency resource allocation information, information related to a precoder to be used by the terminal, MCS level, etc. At this time, the information related to the precoder to be used by the terminal may include information on which PMI to use when using a predefined PMI, what the rank value is, and how to process the channel estimated through the SRS when using a precoder based on the SRS. In addition, since the DU knows that the corresponding MMU is capable of CSI decoding, the DU may transmit scheduling information related to downlink precoding by considering the presence or absence of CSI information received by the MMU at a later point in time than the CSI used by the DU when generating the scheduling information. For example, the DU can convey to the MMU the PMI index and rank value to be used for the corresponding terminal, and can additionally inform the MMU at which point in time the corresponding scheduling information was generated based on the CSI reported by the terminal, and if the MMU receives, decodes, and stores new CSI after that point in time, the MMU can ignore the downlink precoder-related information in the scheduling information received from the DU and determine the downlink precoder based on the CSI stored by the MMU. In this case, if the rank value indicated by the DU and the rank value in the CSI most recently stored by the MMU are different, the MMU can use the corresponding PMI by matching one of the rank values ​​(for example, matching it to the rank value indicated by the DU, or as another example, matching it to the rank in the CSI most recently stored by the MMU), or give priority to the PMI indicated by the DU.For example, if the PMI that can be obtained through the latest CSI has a rank of 1 and the rank of the PMI indicated by the DU is 2, the MMU can use the PMI indicated by the DU. Alternatively, the MMU can check the most recent CSI value that has the same rank as the rank indicated by the DU among the CSI reported by the UE and use the PMI included in the corresponding CSI. For example, if the rank value included in the downlink precoder-related information indicated by the DU is 2, and the corresponding scheduling information is derived from the CSI reported by the UE at time T1, the MMU can determine the downlink precoder using the CSI that has a rank value equal to 2, the rank value indicated by the DU, among the CSI reported by the UE after time T1. If such CSI does not exist, the MMU can use the PMI indicated by the DU as is.

[0564] In step (1675), the MMU can generate a downlink precoder based on the PMI determined in step (1670). If a specific terminal is scheduled in the SU-MIMO manner, the terminal can use the PMI as is, adjust it partially, or use it by linearly combining it with another PMI, etc., as instructed by the DU. If a specific terminal is scheduled in the MU-MIMO manner, the MMU can generate a downlink precoder to be applied to the terminal based on the scheduling information instructed / received from the DU, and consider all channel state information of one or more terminals scheduled in the MU-MIMO manner together, and apply the downlink precoder. The DU can provide such scheduling information to the MMU. The MMU may include information such as the index of the terminals to be scheduled in MU-MIMO mode from the DU, the time and frequency resource locations of the terminals, information on which SRS information or PMI available to each terminal to use when generating a downlink precoder for each terminal, information on which PMI index to use if a specific terminal operates based on PMI, rank information for each terminal, etc. Additionally, if the DU knows that a specific MMU is capable of CSI decoding, when instructing the MMU to generate a downlink precoder, the DU may provide the MMU with information such as whether to generate a downlink precoder based on the most recent CSI information decoded by the MMU or whether to generate a downlink precoder based on the CSI used by the DU when generating scheduling information.

[0565] At step (1680), the MMU may transmit a PDSCH to the terminal by applying the downlink precoder. The MMU may transmit scheduling information for the PDSCH. In addition, the MMU may transmit the PDSCH to the terminal. At this time, the terminal may be scheduled in the form of SU-MIMO or MU-MIMO as described above.

[0566] For the above-described operation, the MMU can convey capability information that it is capable of CSI decoding to the DU. After the DU detects the presence of such an MMU (after confirming that the MMU is capable of CSI decoding), it can instruct the MMU to decode all received CSI or only some specific CSI.

[0567] For example, the MMU can decode and store all CSI it receives. That is, all CSI transmitted by a terminal is stored in the MMU, and the MMU can update the MMU with the latest CSI for each terminal. This can have the advantage that a DU receiving CSI information for different terminals from multiple MMUs can process only non-CSI information (uplink data, HARQ-ACK information, scheduling request information, etc.) without decoding the CSI.

[0568] As another example, the MMU may decode and store only a portion of the CSI it receives, and pass the rest to the DU for the DU to decode. CSI that can be decodable by the MMU and CSI that can be decodable by the DU (and CSI that cannot be decodable by the MMU) may be defined separately. The reason for separately defining CSI that the MMU can selectively decode in this way is that if all CSI is decoded, a computational burden may occur in the MMU, so for example, the total bit length of the CSI is less than / less than a specific value, or the CSI calculation time defined for the terminal is less consumed, so the decoding time at the base station may be less consumed, and / or the CSI has a relatively important meaning (for example, the priority value of the CSI defined / set for the terminal is less than / less than a specific reference value, so that it has a higher priority than the CSI with the reference value (or the CSI with a priority value equal to / exceeding the reference value)), the application time of the CSI can be brought forward through decoding in the MMU.

[0569] Since decoding blocks supporting relatively lower computational performance than DUs may be included during CSI decoding in the MMU, the delay time may increase when decoding CSI if the same channel coding scheme is used. Therefore, different channel codings with optimized decoding complexity may be applied depending on the bit length of the CSI. To this end, it can be assumed that the terminal and the base station apply different channel codings depending on the bit length of the CSI. The terminal can report to the base station whether it supports applying different channel codings according to different CSI bit lengths.

[0570] - If a specific terminal supports this function, the terminal can receive upper layer signaling from the base station, and the upper layer signaling may mean that different channel coding schemes can be applied to CSI reports of different lengths. When the terminal reports CSI to the base station, the channel encoding scheme for the CSI can be determined differently depending on the bit length of the CSI. If the base station receives a CSI report from such a terminal, and the MMU receiving the CSI provides a CSI decoding function, the MMU can decode the CSI report and store it. If the MMU does not provide a CSI decoding function, the MMU does not decode the received CSI and passes it to the DU, so that the DU can perform the decoding.

[0571] - If a specific terminal does not support this function, the terminal may not receive higher layer signaling from the base station indicating that different channel coding schemes may be applied to CSI reports of different lengths. Therefore, the terminal may not be able to support different channel coding schemes for CSI of different lengths. If a specific terminal does not support this function, the terminal may not receive higher layer signaling from the base station indicating that different channel coding schemes may be applied to CSI reports of different lengths. Therefore, the terminal may not support different channel coding schemes for CSI of different lengths. If the MMU provides a CSI decoding function, the MMU may decode the CSI of the terminal and pass the information to the DU, or decode only the CSI of a specific length and pass the information to the DU, and otherwise pass it directly to the DU without decoding. If the MMU does not provide a CSI decoding function, the MMU passes the received CSI to the DU without decoding it, so that the DU can perform the decoding.

[0572]

[0573] If CSI decoding is possible in the MMU, the multiplexing position of the CSI may be adjusted to enable faster and more accurate CSI decoding in the MMU.

[0574] In order to enable the MMU to decode CSI as quickly and accurately as possible, a rule may be established to multiplex CSI around the demodulation reference signal (DMRS) of the PUSCH. For example, when the MMU performs a PUSCH transmission for CSI decoding (PUSCH including CSI, PUSCH including CSI to be decoded in the MMU), it may be restricted to use only PUSCH mapping type B. In addition, in case of PUSCH mapping type B, the position of the first DMRS may be the first position of the PUSCH (the DMRS symbol may start from the first PUSCH symbol. The (first) DMRS symbol may be the first PUSCH symbol position). If HARQ-ACK and CSI are multiplexed together on the PUSCH, it can be decided / defined that the CSI can be sequentially mapped (RE mapping) starting from the available RE positions within the DMRS symbol of the PUSCH, and the mapping (RE mapping) can be performed for the HARQ-ACK after the mapping for the CSI is completed. In this way, by first mapping the CSI from the available RE positions within the DMRS symbol of the PUSCH, the CSI can be mapped around the DMRS. By mapping the CSI around the DMRS in this way, the UE can minimize the error in channel estimation and reduce the delay time for CSI decoding by mapping it before HARQ-ACK.

[0575] To ensure that CSI can be decoded as quickly and accurately as possible in the MMU, when the UE performs a PUSCH transmission for CSI decoding in the MMU, an additional beta offset may be specified to support higher robustness. Furthermore, to minimize decoding latency for CSI, only wideband CSI reporting may be permitted, and only single-part CSI may be supported.

[0576] To enable fast decoding of CSI in the MMU, if the UE is triggered by one or more aperiodic CSI reports via DCI, the UE may be indicated with two slot offsets, and the PUSCH corresponding to the shorter slot offset from the DCI may contain CSI for decoding in the MMU. The remaining slot offset may contain CSI information that is not intended for decoding in the MMU. In this case, different beta offsets may be indicated for the PUSCH corresponding to the shorter slot offset and the PUSCH corresponding to the remaining slot offset, and / or different PUSCH mapping types may be indicated. In this case, the UE may expect PUSCH mapping type B to be indicated for the PUSCH corresponding to the short slot offset. It may expect PUSCH mapping type A to be indicated for the PUSCH corresponding to the long slot offset. Additionally, in order to enable the MMU to quickly obtain CSI, RI and PMI information may be placed first when generating the terminal's CSI reporting information.

[0577] FIG. 17 is a diagram showing the operation of a terminal according to one embodiment of the present disclosure.

[0578] In step 1700, the terminal may transmit terminal capability to the base station. At this time, the terminal capability signaling that can be received by the base station may be for a combination of at least one or more of terminal capabilities indicating support for different channel coding schemes according to the bit length of the CSI, a method for determining the multiplexing position of the CSI within the PUSCH, the additional beta offset indication, the offset of the multiple aperiodic CSI reporting slots, and the CSI reporting information generation method. Step 1700 may be omitted.

[0579] In step 1705, the terminal may receive upper layer signaling from the base station. At this time, the terminal may receive from the base station at least one combination of different channel coding schemes according to the bit length of the CSI, a method for determining the multiplexing position of the CSI within the PUSCH, the additional beta offset indication, the offset of the plurality of aperiodic CSI reporting slots, and each upper layer signaling related to the CSI reporting information generation method.

[0580] At step 1710, the terminal may be notified of a CSI report from the base station using at least one combination of upper layer signaling, MAC-CE signaling, and L1 signaling. Based on this notification, the terminal can confirm the CSI reporting method transmitted to the terminal by the base station.

[0581] At step 1715, the terminal may perform a CSI report. This CSI report may be transmitted to a specific MMU or may be transmitted jointly to multiple MMUs.

[0582] In step 1720, the terminal may receive DCI from the base station, which may include (or include) PDSCH scheduling information. Based on the DCI, the terminal may obtain information related to PDSCH scheduling from the base station. The scheduling information may be related to the CSI reported by the terminal. The scheduling information may be determined based on the CSI reported by the terminal.

[0583] In step 1725, the terminal may receive a PDSCH from the base station. At this time, the downlink precoder applied to the corresponding PDSCH received by the terminal may be based on the CSI reflected in the scheduling for the corresponding PDSCH in the DU, or, if the MMU supports decoding of CSI, may be CSI information received and updated more recently than the CSI reflected in the scheduling for the PDSCH.

[0584] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0585] FIG. 18 is a diagram illustrating the operation of a base station according to one embodiment of the present disclosure.

[0586] In step 1800, the base station may receive terminal capability information from the terminal. At this time, the terminal capability signaling that may be received by the base station may be for a combination of at least one of terminal capabilities indicating support for different channel coding schemes according to the bit length of the CSI, a multiplexing location determination method of the CSI within the PUSCH, the additional beta offset indication, the offset of the multiple aperiodic CSI reporting slots, and the CSI reporting information generation method. Step 1800 may be omitted.

[0587] In step 1805, the base station may transmit upper layer signaling to the terminal. At this time, the base station may configure at least one combination of each upper layer signaling related to different channel coding schemes according to the bit length of the CSI, a multiplexing location determination method of the CSI within the PUSCH, the additional beta offset indication, the offsets of the multiple aperiodic CSI reporting slots, and the CSI reporting information generation method for the terminal.

[0588] In step 1810, the base station may notify the terminal of the CSI report using at least one combination of upper layer signaling, MAC-CE signaling, and L1 signaling. Based on this notification, the terminal can confirm the CSI reporting method transmitted by the base station to the terminal.

[0589] At step 1815, the base station may receive a CSI report. This CSI report may be received from a specific MMU or may be received jointly by multiple MMUs.

[0590] At step 1820, a specific MMU within the base station can decode the CSI received at step 1815. Thereafter, the MMU can transmit the decoded CSI to the DU.

[0591] At step 1825, the DU may perform scheduling for the corresponding terminal based on the CSI information received from the MMU and transmit this information to the MMU. Depending on the scheduling result, the corresponding terminal may be scheduled in SU-MIMO mode or MU-MIMO mode on specific time and frequency resources.

[0592] At step 1830, the MMU may synthesize the scheduling information received from the DU and the CSI information additionally decoded by the MMU to determine the downlink precoder to be applied to the corresponding terminal. At this time, the downlink precoder applied to the corresponding PDSCH received by the terminal may be based on the CSI reflected in the scheduling for the corresponding PDSCH by the DU, or, if the MMU supports decoding of CSI, may be CSI information received and updated more recently than the CSI reflected in the scheduling for the PDSCH.

[0593] In step 1835, the base station may transmit DCI, which may include (or include) PDSCH scheduling information, to the terminal. The terminal may obtain information related to PDSCH scheduling from the base station based on the DCI. The scheduling information may be related to CSI reported by the terminal. The scheduling information may be determined based on the CSI reported by the terminal.

[0594] At step 1840, the base station may transmit a PDSCH to the terminal, and a downlink precoder to be applied thereto may be determined at step 1830.

[0595] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0596] FIG. 19 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0597] Referring to FIG. 19, the terminal may include a transceiver, which refers to a terminal receiving unit (19-00) and a terminal transmitting unit (19-10), a memory (not shown), and a terminal processing unit (19-05, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (19-00, 19-10), the memory, and the terminal processing unit (19-05) 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 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.

[0598] A transceiver unit can transmit and receive signals to and from a base station. The signals may include control information and data. To this end, the transceiver unit may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is merely one embodiment of the transceiver unit, and the components of the transceiver unit are not limited to the RF transmitter and RF receiver.

[0599] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit a signal output from the processor through the wireless channel.

[0600] Memory can store programs and data necessary for the terminal's operation. Furthermore, memory can store control information or data included in signals transmitted and received by the terminal. Memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0601] Additionally, the processor can control a series of processes to enable the terminal to operate according to the aforementioned embodiments. For example, the processor can receive DCI consisting of two layers and control components of the terminal to simultaneously receive multiple PDSCHs. There may be multiple processors, and the processors can perform component control operations of the terminal by executing programs stored in memory.

[0602] FIG. 20 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0603] Referring to FIG. 20, the base station may include a transceiver, which refers to a base station receiver (20-00) and a base station transmitter (20-10), a memory (not shown), and a base station processing unit (20-05, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver units (20-00, 20-10), the memory, and the base station processing unit (20-05) 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 or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0604] The transceiver can transmit and receive signals with the terminal. Here, the signals may include control information and data. To this end, the transceiver may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

[0605] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit the signal output from the processor through the wireless channel.

[0606] The memory can store programs and data necessary for the operation of the base station. Furthermore, the memory can store control information or data included in signals transmitted and received by the base station. The memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0607] The processor can control a series of processes to enable the base station to operate according to the aforementioned embodiments of the present disclosure. For example, the processor can configure two layers of DCIs containing allocation information for multiple PDSCHs and control each component of the base station to transmit them. There may be multiple processors, and the processors can perform component control operations of the base station by executing programs stored in memory.

[0608] The 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.

[0609] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0610] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0611] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0612] In the specific embodiments of the present disclosure described above, components included in the embodiments are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0613] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical contents of the present disclosure and to help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, the above-mentioned embodiments can be combined and operated with each other as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment can be combined with each other to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure can be combined with each other to operate a base station and a terminal. In addition, although the above-mentioned embodiments have been presented based on an FDD LTE system, other modifications based on the technical idea of ​​the above-mentioned embodiments can be implemented with other systems such as a TDD LTE system, a 5G or NR system.

[0614] Meanwhile, the order of description in the drawings explaining the method of the present disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0615] Alternatively, the drawings illustrating the method of the present disclosure may omit some components and include only some components without detracting from the essence of the present disclosure.

[0616] In addition, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment within a scope that does not damage the essence thereof.

[0617] 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 appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. In a method performed by a base station in a communication system, A step of transmitting a first configuration for CSI (channel state information) reporting and a second configuration for one or more CSI-RS (channel state information-reference signal) resources to a terminal through upper layer signaling; A step of transmitting one or more CSI-RSs to the terminal based on the one or more CSI-RS resources; A step of receiving CSI related to one or more CSI-RSs from the terminal, the CSI including a first CSI predefined for a RU (radio unit) of the base station, and the first setting including one or more settings related to the first CSI predefined; A step of performing decoding for the above CSI, wherein the predefined first CSI is decoded in the RU; A step of obtaining scheduling information for a PDSCH (physical downlink shared channel), wherein the scheduling information is related to the CSI; and A method comprising the step of transmitting DCI (downlink control information) including the above scheduling information to the terminal through a PDCCH (physical downlink control channel).

2. In paragraph 1, The above one or more settings include settings related to a UCI (uplink control information) multiplexing scheme in a PUSCH (physical uplink shared channel), wherein the UCI multiplexing scheme is: The DM-RS symbol to which the DM-RS (demodulation reference signal) for the above PUSCH is mapped includes the first symbol among a plurality of symbols to which the PUSCH is mapped; The predefined first CSI is mapped from the available RE (resource element) within the DM-RS symbol; and A method comprising: when HARQ-ACK (hybrid automatic repeat request acknowledgment) information and the predefined first CSI are multiplexed in the PUSCH, the HARQ-ACK information is mapped after the predefined first CSI is mapped; 3. In paragraph 1, The above CSI includes a second CSI predefined for the DU (distributed unit) of the base station, The one or more settings include a setting for a first reporting slot offset and a setting for a second slot offset, wherein the first reporting slot offset is shorter than the second reporting slot offset, The above predefined first CSI is received through a PUSCH corresponding to the first slot offset, A method wherein the above-described second CSI is received via a PUSCH corresponding to the second slot offset.

4. In paragraph 1, One or more of the above settings: Setting of channel coding schemes for the above-described first CSI, wherein the channel coding schemes are different channel coding schemes according to the bit length of the above-described first CSI; and A method comprising setting an additional beta offset for the predefined first CSI received on a PUSCH.

5. In paragraph 1, A step of receiving terminal capability information related to the above-described first CSI from the terminal, The above first setting is a method based on the terminal capability information.

6. In paragraph 1, The decoded predefined first CSI is stored in the RU of the base station and transmitted from the RU of the base station to the DU of the base station, The above scheduling information is obtained from the DU of the base station and transmitted from the DU of the base station to the RU of the base station, The scheduling information transmitted from the DU of the base station includes information related to a downlink precoder and information about the time at which the CSI based on the scheduling information was reported. If the scheduling information transmitted from the DU of the base station based on information about the time at which the CSI was reported is identified as being based on CSI reported at a time earlier than the stored predefined first CSI, the scheduling information is updated by the RU of the base station, and the updated scheduling information is transmitted to the terminal by the RU of the base station. A method in which, when the first rank value corresponding to the CSI reported at the above-mentioned previous point in time and the second rank value corresponding to the stored predefined first CSI are different, the downlink precoder-related information is updated to correspond to one of the first rank value or the second rank value.

7. In the base station of the communication system, Transmitter and receiver; and A processor connected to the transceiver, the processor comprising: Transmitting to the terminal a first configuration for reporting channel state information (CSI) and a second configuration for one or more channel state information-reference signal (CSI-RS) resources via upper layer signaling; Transmitting one or more CSI-RS to the terminal based on the one or more CSI-RS resources; Receiving CSI related to said one or more CSI-RSs from said terminal, said CSI including a first CSI predefined for a RU (radio unit) of said base station, and said first setting including one or more settings related to said first CSI predefined; Decoding is performed for the above CSI, wherein the predefined first CSI is decoded in the RU; Obtain scheduling information for PDSCH (physical downlink shared channel), wherein the scheduling information is related to the CSI; and A base station configured to transmit DCI (downlink control information) including the above scheduling information to the terminal through a PDCCH (physical downlink control channel).

8. In paragraph 7, The above one or more settings include settings related to a UCI (uplink control information) multiplexing scheme in a PUSCH (physical uplink shared channel), wherein the UCI multiplexing scheme is: The DM-RS symbol to which the DM-RS (demodulation reference signal) for the above PUSCH is mapped includes the first symbol among a plurality of symbols to which the PUSCH is mapped; The predefined first CSI is mapped from the available RE (resource element) within the DM-RS symbol; and Including, when HARQ-ACK (hybrid automatic repeat request acknowledgment) information and the predefined first CSI are multiplexed in the PUSCH, the HARQ-ACK information is mapped after the predefined first CSI is mapped; The above CSI includes a second CSI predefined for the DU (distributed unit) of the base station, The one or more settings include a setting for a first reporting slot offset and a setting for a second slot offset, wherein the first reporting slot offset is shorter than the second reporting slot offset, The above predefined first CSI is received through a PUSCH corresponding to the first slot offset, A base station, wherein the above-described second CSI is received via a PUSCH corresponding to the second slot offset.

9. In paragraph 7, One or more of the above settings: Setting of channel coding schemes for the above-described first CSI, wherein the channel coding schemes are different channel coding schemes according to the bit length of the above-described first CSI; and A base station comprising a setting for an additional beta offset for the predefined first CSI received on a PUSCH.

10. In a method performed by a terminal in a communication system, A step of receiving, from a base station, a first configuration for CSI (channel state information) reporting and a second configuration for one or more CSI-RS (channel state information-reference signal) resources through upper layer signaling; A step of receiving one or more CSI-RSs from the base station based on the one or more CSI-RS resources; A step of generating CSI related to said one or more CSI-RSs, said CSI including a first CSI predefined for a radio unit (RU) of said base station, and said first configuration including one or more configurations related to said first CSI predefined; A step of transmitting the CSI to the base station, wherein the predefined first CSI is transmitted to the RU of the base station; and A step of receiving scheduling information for a PDSCH (physical downlink shared channel) from the base station through a PDCCH (physical downlink control channel), The above scheduling information is related to the above CSI, method.

11. In paragraph 9, The above one or more settings include settings related to a UCI (uplink control information) multiplexing scheme in a PUSCH (physical uplink shared channel), wherein the UCI multiplexing scheme is: The DM-RS symbol to which the DM-RS (demodulation reference signal) for the above PUSCH is mapped includes the first symbol among a plurality of symbols to which the PUSCH is mapped; The predefined first CSI is mapped from the available RE (resource element) within the DM-RS symbol; and A method comprising: when HARQ-ACK (hybrid automatic repeat request acknowledgment) information and the predefined first CSI are multiplexed in the PUSCH, the HARQ-ACK information is mapped after the predefined first CSI is mapped; 12. In paragraph 9, The above CSI includes a second CSI predefined for the DU (distributed unit) of the base station, The one or more settings include a setting for a first reporting slot offset and a setting for a second slot offset, wherein the first reporting slot offset is shorter than the second reporting slot offset, The above predefined first CSI is transmitted through the PUSCH corresponding to the first slot offset, A method in which the above-described second CSI is transmitted through a PUSCH corresponding to the second slot offset.

13. In paragraph 9, One or more of the above settings: Setting of channel coding schemes for the above-described first CSI, wherein the channel coding schemes are different channel coding schemes according to the bit length of the above-described first CSI; and A method comprising setting an additional beta offset for the predefined first CSI received on a PUSCH.

14. In paragraph 9, A step of transmitting terminal capability information related to the above-described first CSI to the base station, The above first setting is related to the terminal capability information, the method.

15. At the terminal of the communication system, Transmitter and receiver; and A processor connected to the transceiver, the processor comprising: Receive from a base station, via upper layer signaling, a first configuration for reporting channel state information (CSI) and a second configuration for one or more channel state information-reference signal (CSI-RS) resources; Receiving one or more CSI-RSs from the base station based on the one or more CSI-RS resources; Generating CSI related to said one or more CSI-RSs, said CSI including a first CSI predefined for a RU (radio unit) of said base station, and said first configuration including one or more configurations related to said first predefined CSI; Transmitting the CSI to the base station, the predefined first CSI being transmitted to the RU of the base station; and It is configured to receive scheduling information for PDSCH (physical downlink shared channel) from the base station through PDCCH (physical downlink control channel), The above scheduling information is related to the CSI, terminal.

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