Method and apparatus for estimating downlink channel on basis of sounding reference signal by comparing precoded 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 the operations of a terminal and a base station in a wireless communication system and, more specifically, the present disclosure relates to a method and apparatus for estimating a downlink channel on the basis of a sounding reference signal by comparing precoded channel state information in a communication system. The present disclosure provides an apparatus and method capable of effectively providing services in a mobile communication system.

Description

Method and device for downlink channel estimation based on sounding reference signal through comparison of precoded 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 enhanced downlink channel estimation based on SRS antenna switching 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 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 the various embodiments of the present disclosure described below.

[0010] A method performed by a terminal in a communication system according to one embodiment of the present disclosure comprises the steps of: receiving, through higher layer signaling, a sounding reference signal (SRS)-related configuration including a usage parameter indicating antenna switching; transmitting an SRS corresponding to the antenna switching; receiving a channel state information reference signal (CSI-RS); transmitting a CSI report based on the CSI-RS; receiving a plurality of precoded CSI-RSs, the plurality of precoded CSI-RSs including a first precoded CSI-RS corresponding to the SRS and a second precoded CSI-RS corresponding to the CSI report; and transmitting compensation information based on the plurality of precoded CSI-RSs.

[0011] According to one embodiment of the present disclosure, the correction information is for correction of SRS-based downlink channel estimation corresponding to the antenna switching.

[0012] According to one embodiment of the present disclosure, the correction information is for correction of SRS-based downlink channel estimation corresponding to antenna switching during a certain time period during which SRS-based downlink channel estimation corresponding to antenna switching is applied.

[0013] According to one embodiment of the present disclosure, the predetermined time interval is predefined, set through the upper layer signaling, or determined based on information related to a downlink channel and a hybrid automatic repeat request (HARQ-ACK) corresponding to the downlink channel and SRS-based downlink channel estimation corresponding to the antenna switching.

[0014] According to one embodiment of the present disclosure, a downlink channel received within the predetermined time interval is based on precoding related to SRS-based downlink channel estimation corresponding to the antenna switching corrected according to the correction information.

[0015] According to one embodiment of the present disclosure, the plurality of precoded CSI-RSs are received based on a plurality of CSI-RS resource configurations, the plurality of CSI-RS resource configurations are associated with a CSI reporting configuration, the plurality of CSI-RS resource configurations and the CSI reporting configuration are received via the upper layer signaling, and the CSI reporting configuration includes a reportQuantity parameter that indicates reporting of a CSI related quantity corresponding to the correction information.

[0016] According to one embodiment of the present disclosure, the step of transmitting the correction information includes: determining a first precoder based on the first precoded CSI-RS; determining a second precoder based on the second precoded CSI-RS; determining a first effective channel estimate based on a channel estimate corresponding to the CSI-RS and the first precoder; determining a second effective channel estimate based on the channel estimate corresponding to the CSI-RS and the second precoder; determining a correction value corresponding to the precoder based on the first effective channel estimate and the second effective channel estimate, wherein the correction value is a value at which a difference between the first effective channel estimate and the second effective channel estimate is minimized or a value at which a correlation between the first effective channel estimate and the second effective channel estimate is maximized; and transmitting the correction information including the correction value.

[0017] According to one embodiment of the present disclosure, the method further includes the steps of transmitting terminal capability information related to whether SRS-based downlink channel estimation corresponding to the antenna switching based on the correction information is supported; and the step of receiving, through the upper layer signaling, information indicating activation of SRS-based downlink channel estimation corresponding to the antenna switching based on the correction information.

[0018] According to one embodiment of the present disclosure, a terminal of a communication system includes a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: receive, through higher layer signaling, a sounding reference signal (SRS)-related configuration including a usage parameter indicating antenna switching; transmit an SRS corresponding to the antenna switching; receive a channel state information reference signal (CSI-RS); transmit a CSI report based on the CSI-RS; receive a plurality of precoded CSI-RSs, the plurality of precoded CSI-RSs including a first precoded CSI-RS corresponding to the SRS and a second precoded CSI-RS corresponding to the CSI report; and transmit compensation information based on the plurality of precoded CSI-RSs.

[0019] According to one embodiment of the present disclosure, the correction information is for correction of SRS-based downlink channel estimation corresponding to the antenna switching.

[0020] According to one embodiment of the present disclosure, the correction information is for correction of an SRS-based downlink channel estimation corresponding to the antenna switching during a predetermined time period during which the SRS-based downlink channel estimation corresponding to the antenna switching is applied, and the predetermined time period is predefined, set through the upper layer signaling, or determined based on a downlink channel related to the SRS-based downlink channel estimation corresponding to the antenna switching and HARQ-ACK (hybrid automatic repeat request)-related information corresponding to the downlink channel, and a downlink channel received within the predetermined time period is based on precoding related to the SRS-based downlink channel estimation corresponding to the antenna switching corrected according to the correction information.

[0021] According to one embodiment of the present disclosure, the plurality of precoded CSI-RSs are received based on a plurality of CSI-RS resource configurations, the plurality of CSI-RS resource configurations are associated with a CSI reporting configuration, the plurality of CSI-RS resource configurations and the CSI reporting configuration are received via the upper layer signaling, and the CSI reporting configuration includes a reportQuantity parameter that indicates reporting of a CSI related quantity corresponding to the correction information.

[0022] According to one embodiment of the present disclosure, in transmitting the correction information, the processor is configured to: determine a first precoder based on the first precoded CSI-RS; determine a second precoder based on the second precoded CSI-RS; determine a first effective channel estimate based on a channel estimate corresponding to the CSI-RS and the first precoder; determine a second effective channel estimate based on a channel estimate corresponding to the CSI-RS and the second precoder; determine a correction value corresponding to the precoder based on the first effective channel estimate and the second effective channel estimate, the correction value being a value at which a difference between the first effective channel estimate and the second effective channel estimate is minimized, or a value at which a correlation between the first effective channel estimate and the second effective channel estimate is maximized; and transmit correction information including the correction value.

[0023] According to one embodiment of the present disclosure, the processor is configured to: transmit terminal capability information related to whether SRS-based downlink channel estimation corresponding to the antenna switching based on the correction information is supported; and receive, through the upper layer signaling, information indicating activation of SRS-based downlink channel estimation corresponding to the antenna switching based on the correction information.

[0024] A method performed by a base station in a communication system according to one embodiment of the present disclosure comprises the steps of: transmitting, through higher layer signaling, a sounding reference signal (SRS)-related configuration including a usage parameter indicating antenna switching; receiving an SRS corresponding to the antenna switching; transmitting a channel state information reference signal (CSI-RS); receiving a CSI report corresponding to the CSI-RS; transmitting a plurality of precoded CSI-RSs, the plurality of precoded CSI-RSs including a first precoded CSI-RS corresponding to the SRS and a second precoded CSI-RS corresponding to the CSI report; and receiving compensation information based on the plurality of precoded CSI-RSs.

[0025] According to one embodiment of the present disclosure, the correction information is for correction of SRS-based downlink channel estimation corresponding to the antenna switching.

[0026] According to one embodiment of the present disclosure, the correction information is for correction of an SRS-based downlink channel estimation corresponding to the antenna switching during a predetermined time period during which the SRS-based downlink channel estimation corresponding to the antenna switching is applied, and the predetermined time period is predefined, set through the upper layer signaling, or determined based on a downlink channel related to the SRS-based downlink channel estimation corresponding to the antenna switching and HARQ-ACK (hybrid automatic repeat request)-related information corresponding to the downlink channel, and a downlink channel transmitted within the predetermined time period is based on precoding related to the SRS-based downlink channel estimation corresponding to the antenna switching corrected according to the correction information.

[0027] According to one embodiment of the present disclosure, the plurality of precoded CSI-RSs are based on a plurality of CSI-RS resource configurations, the plurality of CSI-RS resource configurations are associated with a CSI reporting configuration, the plurality of CSI-RS resource configurations and the CSI reporting configuration are transmitted via the upper layer signaling, and the CSI reporting configuration includes a reportQuantity parameter that indicates reporting of a CSI related quantity corresponding to the correction information.

[0028] A base station of 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, through higher layer signaling, a sounding reference signal (SRS) related configuration including a usage parameter indicating antenna switching; receive an SRS corresponding to the antenna switching; transmit a channel state information reference signal (CSI-RS); receive a CSI report corresponding to the CSI-RS; transmit a plurality of precoded CSI-RSs, the plurality of precoded CSI-RSs including a first precoded CSI-RS corresponding to the SRS and a second precoded CSI-RS corresponding to the CSI report; and receive compensation information based on the plurality of precoded CSI-RSs.

[0029] According to one embodiment of the present disclosure, the correction information is for correction of SRS-based downlink channel estimation corresponding to the antenna switching.

[0030] According to one embodiment of the present disclosure, the correction information is for correction of an SRS-based downlink channel estimation corresponding to the antenna switching during a predetermined time period during which the SRS-based downlink channel estimation corresponding to the antenna switching is applied, and the predetermined time period is predefined, set through the upper layer signaling, or determined based on a downlink channel related to the SRS-based downlink channel estimation corresponding to the antenna switching and HARQ-ACK (hybrid automatic repeat request)-related information corresponding to the downlink channel, and a downlink channel transmitted within the predetermined time period is based on precoding related to the SRS-based downlink channel estimation corresponding to the antenna switching corrected according to the correction information.

[0031] The above-described embodiments are only some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of 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.

[0032] The disclosed embodiment provides a device and method capable of effectively providing a service in a mobile communication system.

[0033] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by a person having ordinary skill in the art based on the detailed description below.

[0034] 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.

[0035] 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.

[0036] FIG. 3 is a diagram illustrating an example of base station beam allocation according to a transmission configuration indicator (TCI) state setting in a wireless communication system according to one embodiment of the present disclosure.

[0037] FIG. 4 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.

[0038] FIG. 5 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.

[0039] Figure 6 is a diagram illustrating an example of an aperiodic CSI reporting method.

[0040] FIG. 7 is a diagram illustrating an SRS antenna switching operation according to one embodiment of the present disclosure.

[0041] Figure 8 is an example comparing a method of estimating a downlink channel based on CSI-RS and a method of estimating a downlink channel based on SRS and reciprocity.

[0042] Figure 9 illustrates an example of a case where a terminal performs SRS antenna switching and a base station acquires a downlink channel when the terminal supports 1T4R.

[0043] Fig. 10 is a drawing showing an example of a terminal structure supporting four receiving antennas.

[0044] Fig. 11 is a diagram illustrating an example of an operation flow chart of a base station and a terminal according to an embodiment.

[0045] FIG. 12 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0046] FIG. 13 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0047] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0048] 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 avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0049] 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.

[0050] 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 these may vary depending on the intention or custom of the user or operator. Therefore, their definitions should be made based on the contents throughout the specification.

[0051] 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 with 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.

[0052] 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).

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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).

[0058] 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.

[0059] 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, due to the nature of the service, terminals supporting mMTC are likely to be located in shadow areas, such as basements, beyond cell coverage. This 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.

[0060] 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 URLLC-enabled services, 5G systems must provide shorter Transmit Time Intervals (TTIs) than other services, while simultaneously allocating extensive resources in the frequency band to ensure communication link reliability.

[0061] 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.

[0062] Hereinafter, a / b can be understood as at least one of a or b.

[0063] [NR time-frequency resources]

[0064] Below, the frame structure of the 5G system is described in more detail with reference to drawings.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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 ( ). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In an example of FIG. 2, the cases where the subcarrier spacing setting value μ = 0 (204) and μ = 1 (205) are illustrated. When μ = 0 (204), 1 subframe (201) may be composed of one slot (202), and when μ = 1 (205), 1 subframe (201) may be composed of two slots (203). That is, the number of slots per subframe ( ) may vary, and accordingly the number of slots per frame ( ) may vary. Depending on the subcarrier spacing setting μ and can be defined as [Table 1] below.

[0069] [Table 1]

[0070]

[0071] [QCL, TCI state]

[0072] In a wireless communication system, one or more different antenna ports (or one or more channels, signals, and combinations thereof, but for convenience, they will be referred to as different antenna ports in the following description of the present disclosure) can be associated with each other by QCL (Quasi co-location) settings as shown in [Table 2] below. The TCI state is to notify the QCL relationship between the PDCCH (or PDCCH DMRS) and other RSs or channels. When a reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) are QCLed with each other, it means that the terminal is allowed to apply some or all of the large-scale channel parameters estimated at the antenna port A to the channel measurement from the antenna port B. QCL may need to relate different parameters depending on the situation, such as 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) radio resource management (RRM) affected by average gain, and 4) beam management (BM) affected by spatial parameters. Accordingly, NR supports four types of QCL relationships, as shown in [Table 2] below.

[0073] [Table 2]

[0074]

[0075] The above spatial RX parameter may collectively refer to some or all of various parameters, such as Angle of arrival (AoA), Power Angular Spectrum (PAS) of AoA, Angle of departure (AoD), PAS of AoD, transmit / receive channel correlation, transmit / receive beamforming, and spatial channel correlation.

[0076] The above QCL relationship can be set to the terminal through the RRC parameters TCI-State and QCL-Info as shown in Table 9 below. Referring to [Table 3], the base station can set one or more TCI states to the terminal and inform the RS referencing the ID of the TCI state, i.e., up to two QCL relationships (qcl-Type1, qcl-Type2) for the target RS. At this time, each QCL information (QCL-Info) included in the above TCI state includes the serving cell index and BWP index of the reference RS indicated by the corresponding QCL information, the type and ID of the reference RS, and the QCL type as shown in [Table 2] above.

[0077] [Table 3]

[0078]

[0079] Figure 3 is a diagram illustrating an example of base station beam allocation according to TCI state settings.

[0080] Referring to FIG. 3, the base station can transmit information about N different beams to the terminal through N different TCI states. For example, in case of N=3 as shown in FIG. 3, the base station can notify that the antenna ports referencing the different TCI states 300, 305, or 310 have different spatial Rx parameters, i.e., are associated with different beams, by setting the qcl-Type2 parameter included in the three TCI states (300, 305, 310) to be associated with the CSI-RS or SSB corresponding to the different beams and to QCL type D.

[0081] [Table 4] to [Table 8] below show valid TCI state settings according to target antenna port type.

[0082] [Table 4] shows valid TCI state settings when the target antenna port is CSI-RS for tracking (i.e., TRS). The TRS refers to NZP CSI-RS with the repetition parameter not set and trs-Info set to true among CSI-RSs. Setting 3 in Table 10 can be used for aperiodic TRS.

[0083] [Table 4]

[0084] Set a valid TCI state when the target antenna port is CSI-RS for tracking (TRS).

[0085]

[0086] [Table 5] shows valid TCI state settings when the target antenna port is a CSI-RS for CSI. The CSI-RS for CSI refers to an NZP CSI-RS in which a parameter indicating repetition (e.g., repetition parameter) is not set among the CSI-RSs and trs-Info is not set to true.

[0087] [Table 5]

[0088] Set a valid TCI state when the target antenna port is CSI-RS for CSI.

[0089]

[0090] [Table 6] shows the valid TCI state settings when the target antenna port is CSI-RS for beam management (BM, synonymous with CSI-RS for L1 RSRP reporting). The CSI-RS for BM refers to an NZP CSI-RS in which the repetition parameter is set to On or Off among CSI-RSs and trs-Info is not set to true.

[0091] [Table 6]

[0092] Set a valid TCI state when the target antenna port is CSI-RS for BM (for L1 RSRP reporting).

[0093]

[0094] [Table 7] shows the valid TCI state settings when the target antenna port is PDCCH DMRS.

[0095] [Table 7]

[0096] Set a valid TCI state when the target antenna port is PDCCH DMRS.

[0097]

[0098] [Table 8] shows the valid TCI state settings when the target antenna port is PDSCH DMRS.

[0099] [Table 8]

[0100] Set a valid TCI state when the target antenna port is PDSCH DMRS.

[0101]

[0102] A representative QCL setting method according to the above [Table 4] to [Table 8] is to set and operate the target antenna port and reference antenna port for each step as "SSB" -> "TRS" -> "CSI-RS for CSI, or CSI-RS for BM, or PDCCH DMRS, or PDSCH DMRS." Through this, it is possible to link statistical characteristics that can be measured from SSB and TRS to each antenna port to assist the terminal's receiving operation.

[0103] [Unified TCI state]

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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).

[0114] 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).

[0115] FIG. 4 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.

[0116] - DCI format 1_1 or 1_2 with DL assignment (400): If the terminal receives DCI format 1_1 or 1_2 including downlink data channel scheduling information from the base station (401) 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 (405), and can transmit a PUCCH including an HARQ-ACK indicating whether reception of the DCI and the PDSCH is successful (410). 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.

[0117] - DCI format 1_1 or 1_2 without DL assignment (450): If the terminal receives DCI format 1_1 or 1_2 from the base station that does not include downlink data channel scheduling information (455) 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.

[0118] ■ Includes scrambled CRC using CS-RNTI.

[0119] ■ The value of all bits assigned to all fields used as RV (Redundancy Version) fields is 1.

[0120] ■ The value of all bits assigned to all fields used as MCS (Modulation and Coding Scheme) fields is 1.

[0121] ■ The value of all bits assigned to all fields used as NDI (New Data Indication) fields is 0.

[0122] ■ 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.

[0123] 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 (460).

[0124] - For both DCI format 1_1 or 1_2 with DL assignment (400) and without DL assignment (450), if a new TCI state indicated through DCI (401, 455) 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 (420, 470) after the time equal to BAT (beam application time, 415, 465) after the PUCCH transmission (430, 480), and can use the previously indicated TCI-state until (425, 475) before the corresponding slot (420, 470).

[0125] - For both DCI format 1_1 or 1_2 with DL assignment (400) and without DL assignment (450), 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] [Unified TCI state MAC-CE]

[0131] 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.

[0132] FIG. 5 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 one embodiment of the present disclosure. The meaning of each field within the MAC-CE structure may be as follows.

[0133] - Serving Cell ID (500): 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.

[0134] - DL BWP ID (505): 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.

[0135] - UL BWP ID (510): This field can indicate which UL BWP the corresponding 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.

[0136] - Pi (515): 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 the value of Pi is 1, it means that the corresponding ith code point has multiple TCI states, which may mean that the corresponding code point may include a separate DL TCI state and a separate UL TCI state. If the value of Pi is 0, it means that the corresponding ith code point has a single TCI state, which may mean that the corresponding code point may include either a joint TCI state, a separate DCI TCI state, or a separate UL TCI state.

[0137] - D / U (520): 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.

[0138] - TCI state ID (525): 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.

[0139] - R: Indicates reserved bit and can be set to 0.

[0140] For the MAC-CE structure of FIG. 5 described above, the terminal can include the third octet including the P1, P2, …, P8 fields in FIG. 5 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. 5 described above, the terminal can omit the third octet including the P1, P2, …, P8 fields in FIG. 5 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. 5 can be regarded as R fields, and all corresponding R fields can be set to 0 bits.

[0141] [CSI resource configuration]

[0142] 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.

[0143] 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 as shown in [Table 9] to convey information regarding resource settings.

[0144] [Table 9]

[0145]

[0146] [Table 9] 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).

[0147] For example, if the resource set includes CSI-RS, the base station and the terminal can exchange signaling information as in [Table 10] to convey information about the resource set.

[0148] [Table 10]

[0149]

[0150] In [Table 10], 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).

[0151] 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 11], to convey information about CSI-RS resources.

[0152] [Table 11]

[0153]

[0154] In [Table 11], 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.

[0155] - nzp-CSI-RS-ResourceId: CSI-RS resource index

[0156] - resourceMapping: Resource mapping information for CSI-RS resources

[0157] - powerControlOffset: Ratio between PDSCH EPRE (Energy Per RE) and CSI-RS EPRE

[0158] - powerControlOffsetSS: Ratio between SS / PBCH block EPRE and CSI-RS EPRE

[0159] - scramblingID: scrambling index of the CSI-RS sequence

[0160] - periodicityAndOffset: Transmission period and slot offset of the CSI-RS resource

[0161] - qcl-InfoPeriodicCSI-RS: TCI-state information if the CSI-RS is a periodic CSI-RS.

[0162] 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 12] below.

[0163] [Table 12]

[0164]

[0165]

[0166] [Table 12] shows the frequency resource density, CDM type, frequency axis of CSI-RS component RE pattern and time axis start position that can be set according to the number of CSI-RS ports (X). , represents the number of frequency-axis REs (k') and the number of time-axis REs (l') of the CSI-RS component RE pattern. 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 designated without limitation of subcarriers in a PRB (Physical Resource Block), and the CSI-RS RE position may be designated 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.

[0167] [CSI report configuration]

[0168] 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.

[0169] 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 13] to convey information regarding report settings.

[0170] [Table 13]

[0171]

[0172]

[0173]

[0174] [Table 13] Signaling information CSI-ReportConfig contains information about each report setting. The information contained in the signaling information CSI-ReportConfig may have the following meanings.

[0175] - reportConfigId: report setting index

[0176] - carrier: serving cell index

[0177] - resourcesForChannelMeasurement: resource setting index for channel measurement that has a relationship with report settings

[0178] - csi-IM-ResourcesForInterference: Resource setting index containing CSI-IM resources for interference measurement that have a relationship with report settings.

[0179] - nzp-CSI-RS-ResourcesForInterference: Resource setting index containing CSI-RS resources for interference measurement that are linked to report settings.

[0180] - 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.

[0181] - 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).

[0182] - reportFreqConfiguration: Indicates whether the channel information being reported 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.

[0183] - timeRestrictionForChannelMeasurements: Whether the reference signal for channel measurement among the reference signals referenced by the reported channel information has a time axis restriction.

[0184] - timeRestrictionForInterferenceMeasurements: Whether the time axis of the reference signal for interference measurement is restricted among the reference signals referenced by the reported channel information.

[0185] - codebookConfig: Codebook information referenced by the channel information being reported

[0186] - groupBasedBeamReporting: Whether to group beams in channel reporting

[0187] - cqi-Table: CQI table index referenced by the reported channel information

[0188] - subbandSize: Index indicating the subband size of channel information

[0189] - non-PMI-PortIndication: Port mapping information referenced when reporting non-PMI channel information.

[0190] 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.

[0191] 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).

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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).

[0197] 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.

[0198] - CSI-IM resources for interference measurements

[0199] - NZP CSI-RS resources for interference measurements

[0200] - NZP CSI-RS resources for channel measurements

[0201] 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.

[0202] 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 14] below.

[0203] [Table 14]

[0204]

[0205] 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.

[0206] - If all bits in the CSI request field are 0, this may mean that no CSI report is requested.

[0207] - 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.

[0208] - 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.

[0209] [Table 15] below shows an example of the relationship between a CSI request indicator and the CSI trigger state that can be indicated by the indicator.

[0210] [Table 15]

[0211]

[0212] 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.

[0213] Figure 6 is a diagram illustrating an example of an aperiodic CSI reporting method.

[0214] In an example (600) of FIG. 6, the terminal can monitor the PDCCH (601) to obtain DCI format 0_1, from which scheduling information and CSI request information for the PUSCH (605) can be obtained. The terminal can obtain resource information for the CSI-RS (602) to be measured from the received CSI request indicator. The terminal can determine when to perform measurement on the transmitted CSI-RS (602) 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 16] below.

[0215] [Table 16]

[0216]

[0217] An example (600) of Fig. 6 shows an example in which the aforementioned offset value is set to X=0. In this case, the terminal can receive the CSI-RS (602) in a slot (corresponding to slot 0 (606) of Fig. 6) 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 (605). The terminal can obtain scheduling information (information corresponding to each field of the aforementioned DCI format 0_1) for the PUSCH (605) for CSI reporting from the DCI format 0_1. As an example, the terminal can obtain information on a slot in which the PUSCH (605) is to be transmitted from the aforementioned time domain resource allocation information for the PUSCH (605) in the DCI format 0_1. In an example (600) of FIG. 6, the terminal acquires a K2 value corresponding to a slot offset value for PDCCH-to-PUSCH as 3, and accordingly, the PUSCH (605) can be transmitted in slot 3 (609), which is 3 slots away from slot 0 (606), at the time when the PDCCH (601) is received.

[0218] In an example (610) of FIG. 6, the terminal can monitor the PDCCH (611) to obtain DCI format 0_1, and can obtain scheduling information and CSI request information for the PUSCH (615) from this. The terminal can obtain resource information for the CSI-RS (612) to be measured from the received CSI request indicator. An example (610) of FIG. 6 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 (612) in a slot (corresponding to slot 0 (616) of FIG. 6) 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 (615).

[0219] 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 17] below.

[0220] [Table 17]

[0221]

[0222]

[0223] 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.

[0224] 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.

[0225] [CSI computation time]

[0226] 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 the uplink symbol that starts the CP (cyclic prefix). Here, the detailed value of Z is as described below. And μ is numerology. In this case, μ 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, μ 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.

[0227] 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 to be 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 μ is numerology. In this case, μ 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, μ 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.

[0228] 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.

[0229] 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.

[0230] The Z, Z' symbols for calculating the CSI computation time mentioned above follow [Table 18] and [Table 19] 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 19]. 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 18]. 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 19]. Follow the values. X1, X2, X3, and X4 in [Table 19] represent the UE capability for beam reporting time, and KB1 and KB2 in [Table 19] 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, Z, Z' symbols are used in [Table 19]. Follow the value.

[0231] [Table 18]

[0232]

[0233] [Table 19]

[0234]

[0235] [CSI reference resource]

[0236] 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.

[0237] 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.

[0238] 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.

[0239] 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.

[0240] - 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.

[0241] - 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] - 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'.

[0246] - 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'

[0247] 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).

[0248] 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.

[0249] 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 Then, the number of channel information calculation units required for a total of N CSI reports 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 20] below.

[0250] [Table 20]

[0251]

[0252] If the number of channel information calculations required by a terminal for multiple CSI reports at a certain point in time is greater than the number of channel information calculation units (N_CPU) that the terminal can calculate simultaneously, 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 time that the channel information calculation required for the CSI report occupies the CPU and the priority of the channel information to be reported. For example, the channel information update may not be considered for the CSI report whose channel information calculation required for the CSI report starts at the latest time that the CPU occupies, and it is possible to preferentially not consider updating channel information for a CSI report whose channel information priority is lower.

[0253] The priority of the above channel information can be determined by referring to [Table 21] below.

[0254] [Table 21]

[0255]

[0256] The CSI priority for a CSI report is determined through the priority value PriiCSI(y,k,c,s) in [Table 21]. Referring to [Table 21], 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.

[0257] 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.

[0258] [PDCCH: DCI related]

[0259] Next, we will specifically explain downlink control information (DCI) in 5G systems.

[0260] 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.

[0261] 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.

[0262] 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).

[0263] 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 22] below.

[0264] [Table 22]

[0265]

[0266] 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 23] below.

[0267] [Table 23]

[0268]

[0269]

[0270] 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 24] below.

[0271] [Table 24]

[0272]

[0273] 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 25] below.

[0274] [Table 25]

[0275]

[0276] [PUSCH: Transmission method related]

[0277] Next, we describe the scheduling method for PUSCH transmission. PUSCH transmission can be dynamically scheduled by the UL grant within the DCI or can operate by configured grant Type 1 or Type 2. Dynamic scheduling instructions for PUSCH transmission are possible in DCI format 0_0 or 0_1.

[0278] Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving configuredGrantConfig including rrc-ConfiguredUplinkGrant of [Table 26] through higher-order signaling, without receiving UL grant in DCI. Configured grant Type 2 PUSCH transmission can be semi-persistently scheduled by UL grant in DCI after receiving configuredGrantConfig not including rrc-ConfiguredUplinkGrant of [Table 26] through higher-order signaling. When PUSCH transmission operates by configured grant, parameters applied to PUSCH transmission are applied through configuredGrantConfig of higher-order signaling of [Table 26], except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH provided by pusch-Config of [Table 27]. If the terminal has been provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 26], the terminal applies tp-pi2BPSK in pusch-Config of [Table 27] to PUSCH transmission operated by the configured grant.

[0279] [Table 26]

[0280]

[0281]

[0282] Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission can follow a codebook-based transmission method or a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in the upper signaling, pusch-Config in [Table 27], is 'codebook' or 'nonCodebook'.

[0283] As described above, PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can be semi-statically configured by configured grant. If the UE is instructed to schedule PUSCH transmission via DCI format 0_0, the UE performs beam configuration for PUSCH transmission using pucch-spatialRelationInfoID corresponding to the UE-specific PUCCH resource corresponding to the minimum ID within the activated uplink BWP within the serving cell, and the PUSCH transmission is based on a single antenna port. The UE does not expect scheduling for PUSCH transmission via DCI format 0_0 within a BWP where a PUCCH resource including pucch-spatialRelationInfo is not configured. If the UE does not configure txConfig in pusch-Config of [Table 27], the UE does not expect to be scheduled with DCI format 0_1.

[0284] [Table 27]

[0285]

[0286] Next, we describe codebook-based PUSCH transmission. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, or can operate semi-statically based on a configured grant. When codebook-based PUSCH is dynamically scheduled via DCI format 0_1 ​​or semi-statically configured via a configured grant, the UE determines a precoder for PUSCH transmission based on the SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and transmission rank (the number of PUSCH transmission layers).

[0287] At this time, the SRI can be given through the SRS resource indicator field in the DCI or configured through the srs-ResourceIndicator higher-level signaling. The UE is configured with at least one SRS resource when transmitting a codebook-based PUSCH, and can be configured with up to two. When the UE receives an SRI through the DCI, the SRS resource indicated by the SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH containing the SRI. In addition, the TPMI and transmission rank can be given through the precoding information and number of layers fields in the DCI or configured through the precodingAndNumberOfLayers higher-level signaling. The TPMI is used to indicate the precoder applied to the PUSCH transmission. If the UE is configured with one SRS resource, the TPMI is used to indicate the precoder to be applied to the configured one SRS resource. When a terminal is configured with multiple SRS resources, TPMI is used to indicate the precoder to be applied in the SRS resource indicated through SRI.

[0288] The precoder to be used for PUSCH transmission is selected from an uplink codebook having the same number of antenna ports as the nrofSRS-Ports value in the upper layer signaling, SRS-Config. In codebook-based PUSCH transmission, the UE determines the codebook subset based on the TPMI and codebookSubset in the upper layer signaling, pusch-Config. The codebookSubset in the upper layer signaling, pusch-Config, can be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the UE to the base station. If the UE reported 'partialAndNonCoherent' as the UE capability, the UE does not expect the value of codebookSubset in the upper layer signaling to be set to 'fullyAndPartialAndNonCoherent'. Additionally, if the UE reports 'nonCoherent' as the UE capability, the UE does not expect the value of the upper signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in the upper signaling SRS-ResourceSet points to two SRS antenna ports, the UE does not expect the value of the upper signaling codebookSubset to be set to 'partialAndNonCoherent'.

[0289] The terminal can be configured with one SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', and one SRS resource in the SRS resource set can be indicated via SRI. If multiple SRS resources are configured in the SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', the terminal expects that the value of nrofSRS-Ports in the upper signaling SRS-Resource is set to the same value for all SRS resources.

[0290] The terminal transmits to the base station one or more SRS resources included in the SRS resource set in which the usage value is set to 'codebook' according to upper signaling, and the base station selects one of the SRS resources transmitted by the terminal and instructs the terminal to perform PUSCH transmission using transmission beam information of the corresponding SRS resource. At this time, in codebook-based PUSCH transmission, the SRI is used as information for selecting an index of one SRS resource and is included in the DCI. Additionally, the base station includes in the DCI information indicating the TPMI and rank to be used by the terminal for PUSCH transmission. The terminal performs PUSCH transmission by applying the indicated rank and the precoder indicated by the TPMI based on the transmission beam of the corresponding SRS resource using the SRS resource indicated by the SRI.

[0291] Next, we describe non-codebook-based PUSCH transmission. Non-codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can operate semi-statically based on a configured grant. If at least one SRS resource is configured within an SRS resource set in which the usage value in the upper signaling, SRS-ResourceSet, is set to 'nonCodebook', the UE can be scheduled for non-codebook-based PUSCH transmission via DCI format 0_1.

[0292] For an SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be configured with one connected NZP CSI-RS resource (non-zero power CSI-RS). The UE can perform calculations for a precoder for SRS transmission by measuring the NZP CSI-RS resource connected to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource connected to the SRS resource set and the first symbol of the aperiodic SRS transmission at the UE is less than 42 symbols, the UE does not expect information about the precoder for SRS transmission to be updated.

[0293] If the value of resourceType in the upper signaling SRS-ResourceSet is set to 'aperiodic', the connected NZP CSI-RS is indicated by the SRS request field in DCI format 0_1 ​​or 1_1. At this time, if the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, the presence of the connected NZP CSI-RS is indicated when the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not '00'. At this time, the DCI must not indicate cross-carrier or cross BWP scheduling. In addition, if the value of the SRS request indicates the presence of an NZP CSI-RS, the NZP CSI-RS is located in the slot in which the PDCCH including the SRS request field is transmitted. At this time, the TCI states set for the scheduled subcarriers are not set to QCL-TypeD.

[0294] If a periodic or semi-persistent SRS resource set is configured, the associated NZP CSI-RS can be indicated through the associatedCSI-RS within the upper-level signaling SRS-ResourceSet. For non-codebook-based transmission, the UE does not expect the upper-level signaling spatialRelationInfo for the SRS resource and the associatedCSI-RS within the upper-level signaling SRS-ResourceSet to be configured together.

[0295] When multiple SRS resources are configured, the UE can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. At this time, the SRI can be indicated through the SRS resource indicator field in the DCI or can be set through the srs-ResourceIndicator, which is a higher-level signaling. Similar to the codebook-based PUSCH transmission described above, when the UE receives an SRI through the DCI, the SRS resource indicated by the SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH containing the SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be simultaneously transmitted in the same symbol within one SRS resource set and the maximum number of SRS resources are determined by the UE capability reported by the UE to the base station. At this time, the SRS resources that the UE simultaneously transmits occupy the same RB. The UE configures one SRS port for each SRS resource. Only one SRS resource set with the usage value set to 'nonCodebook' in the upper signaling SRS-ResourceSet can be set, and up to four SRS resources for non-codebook based PUSCH transmission can be set.

[0296] The base station transmits one NZP-CSI-RS associated with an SRS resource set to the terminal, and the terminal calculates a precoder to be used when transmitting one or more SRS resources within the SRS resource set based on the result measured upon reception of the NZP-CSI-RS. When the terminal transmits one or more SRS resources within the SRS resource set with usage set to 'nonCodebook' to the base station, the terminal applies the calculated precoder, and the base station selects one or more SRS resources from the received one or more SRS resources. At this time, in non-codebook based PUSCH transmission, the SRI represents an index that can express a combination of one or more SRS resources, and the SRI is included in the DCI. At this time, the number of SRS resources indicated by the SRI transmitted by the base station can be the number of transmission layers of the PUSCH, and the terminal transmits the PUSCH by applying the precoder applied to SRS resource transmission to each layer.

[0297] [PUSCH: Transmission Power Related]

[0298] Below, a method for determining the transmission power of an uplink data channel in a 5G system is specifically described.

[0299] In a 5G system, the transmission power of an uplink data channel can be determined using the following [Mathematical Formula 1].

[0300] [Mathematical Formula 1]

[0301]

[0302] In [Mathematical Formula 1], j represents the grant type of PUSCH, and specifically, j=0 is a PUSCH grant for random access response, j=1 is a configured grant, means dynamic grant. means the maximum output power set to the terminal for carrier f of supporting cell c for PUSCH transmission occasion i. is set as a higher layer parameter and can be determined through upper layer settings and SRI (in case of dynamic grant PUSCH). It is a parameter composed of the sum of . means the bandwidth for resource allocation expressed as the number of resource blocks for PUSCH PUSCH transmission occasion i, It means a value determined according to the MCS (Modulation Coding Scheme) and the type of information transmitted via PUSCH (e.g., whether UL-SCH is included or CSI is included, etc.). refers to a value that can be determined (in case of dynamic grant PUSCH) through upper layer settings and SRI (SRS Resource Indicator) as a value to compensate for path loss. refers to a downlink path loss estimate estimated by the terminal through a reference signal whose reference signal index is qd, and the reference signal index qd can be determined by the terminal through a higher layer configuration and SRI (in the case of a dynamic grant PUSCH or a configured grant PUSCH based on ConfiguredGrantConfig that does not include a higher layer configuration rrc-ConfiguredUplinkGrant (type 2 configured grant PUSCH)) or through a higher layer configuration. can be supported in both accumulation and absolute modes as closed loop power adjustment values. If the upper layer parameter tpc-Accumulation is not set in the terminal, the closed loop power adjustment value can be determined in accumulation mode. In this case, is for transmitting PUSCH transmission occasion i-i0 with the closed loop power adjustment value for the previous PUSCH transmission occasion i-i0. To transmit PUSCH transmission occasion i from the symbol Between symbols, the sum of the TPC command values ​​for the closed loop index l received via DCI is determined. If the upper layer parameter tpc-Accumulation is set in the terminal, is the TPC command value for the closed loop index l received via DCI. is determined. The closed loop index l can be set to 0 or 1 if the upper layer parameter twoPUSCH-PC-AdjustmentStates is set in the terminal, and its value can be determined through the upper layer configuration and SRI (in case of dynamic grant PUSCH). The TPC command field and TPC value in the DCI according to the accumulation method and the absolute method. The mapping relationship can be defined as shown in [Table 28] below.

[0303] [Table 28]

[0304]

[0305] [PUSCH: TPMI Related]

[0306] Next, we describe the TPMI (Transmit Precoding Matrix Indicator) indicated by the base station through DCI during codebook-based PUSCH transmission.

[0307] If the terminal is scheduled for 1-layer transmission using a single PUSCH antenna port by the base station via DCI or higher layer signaling, the TPMI can be defined as W=1. Otherwise, that is, if the terminal is scheduled for 1-layer or higher PUSCH scheduling using multiple PUSCH antenna ports by the base station via DCI or higher layer signaling, the TPMI W can be defined through [Table 29] to [Table 35] below.

[0308] [Table 29]

[0309]

[0310] The above [Table 29] shows the TPMI of 1 layer when the terminal has two PUSCH antenna ports. In the above [Table 29], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal to select one of TPMI index 0 and 1, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal to select one of TPMI index 0 to 5.

[0311] [Table 30]

[0312]

[0313] The above [Table 30] shows the TPMI for a 1-layer case where the terminal has 4 PUSCH antenna ports, transform precoding is used (i.e., DFTS-OFDM waveform is used). In the above [Table 30], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 3, if the terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 11, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 27.

[0314] [Table 31]

[0315]

[0316] The above [Table 31] shows the TPMI for a 1-layer case where the terminal has 4 PUSCH antenna ports, no transform precoding is used (i.e., CP-OFDM waveform is used). In the above [Table 31], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 3, if the terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 11, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 27.

[0317] [Table 32]

[0318]

[0319] The above [Table 32] shows a 2-layer TPMI when a terminal has two PUSCH antenna ports, no transform precoding is used (i.e., a CP-OFDM waveform is used). In the above [Table 32], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal to select TPMI index 0, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal to select one of TPMI index 0 to 2.

[0320] [Table 33]

[0321]

[0322] The above [Table 33] shows a 2-layer TPMI when a terminal has 4 PUSCH antenna ports, no transform precoding is used (i.e., a CP-OFDM waveform is used). In the above [Table 33], if a terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 5, if a terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 13, and if a terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 21.

[0323] [Table 34]

[0324]

[0325] The above [Table 34] shows the TPMI for a 3-layer case where the terminal has 4 PUSCH antenna ports, no transform precoding is used (i.e., CP-OFDM waveform is used). In the above [Table 34], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by TPMI index 0, if the terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by one of TPMI indexes 0 to 2, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by one of TPMI indexes 0 to 6.

[0326] [Table 35]

[0327]

[0328] The above [Table 35] shows a 4-layer TPMI when a terminal has 4 PUSCH antenna ports, no transform precoding is used (i.e., a CP-OFDM waveform is used). In the above [Table 35], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by TPMI index 0, if the terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by one of TPMI indexes 0 to 2, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by one of TPMI indexes 0 to 4.

[0329] [SRS related]

[0330] 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.

[0331] - srs-ResourceSetId: SRS resource set index

[0332] - srs-ResourceIdList: A set of SRS resource indices referenced in the SRS resource set.

[0333] - 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.

[0334] - 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'.

[0335] - alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter settings for adjusting the transmission power of the SRS resource referenced in the SRS resource set.

[0336] 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.

[0337] 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 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.

[0338] 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.

[0339] 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.

[0340] 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.

[0341] 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.

[0342] [Table 36]

[0343]

[0344] The spatialRelationInfo setting information in [Table 36] 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 37] below.

[0345] [Table 37]

[0346]

[0347] 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 the 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 the 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 the srs as the transmission beam for the corresponding SRS transmission.

[0348] [SRS: Antenna switching]

[0349] Below, SRS for antenna switching is described.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] - 't1r2': Terminal capability report value indicating that the terminal is capable of 1T2R operation.

[0354] - 't1r1-t1r2': Terminal capability report value indicating that the terminal is capable of 1T1R or 1T2R operation.

[0355] - 't2r4': Terminal capability report value indicating that the terminal is capable of 2T4R operation.

[0356] - 't1r4': Terminal capability report value indicating that the terminal is capable of 1T4R operation.

[0357] - 't1r6': Terminal capability report value indicating that the terminal is capable of 1T6R operation.

[0358] - 't1r8': Terminal capability report value indicating that the terminal is capable of 1T8R operation.

[0359] - 't2r6': Terminal capability report value indicating that the terminal is capable of 2T6R operation.

[0360] - 't2r8': Terminal capability report value indicating that the terminal is capable of 2T8R operation.

[0361] - 't4r8': Terminal capability report value indicating that the terminal is capable of 4T8R operation.

[0362] - 't1r1-t1r2-t1r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, or 1T4R operation.

[0363] - 't1r4-t2r4': Terminal capability report value indicating that the terminal is capable of 1T4R or 2T4R operation.

[0364] - 't1r1-t1r2-t2r2-t2r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, or 2T4R operation.

[0365] - 't1r1-t1r2-t2r2-t1r4-t2r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, 1T4R, or 2T4R operation.

[0366] - 't1r1': Terminal capability report value indicating that the terminal is capable of 1T1R operation.

[0367] - 't2r2': Terminal capability report value indicating that the terminal is capable of 2T2R operation.

[0368] - 't1r1-t2r2': Terminal capability report value indicating that the terminal is capable of 1T1R or 2T2R operation.

[0369] - 't4r4': Terminal capability report value indicating that the terminal is capable of 4T4R operation.

[0370] - 't1r1-t2r2-t4r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 2T2R, or 4T4R operation.

[0371] [1T2R]

[0372] For the 1T2R operation of the terminal, upper layer signaling from the base station can be set for at least one combination of the following items, and operation can be performed accordingly.

[0373] - If the terminal reports some or all of the terminal capability reports srs-AntennaSwitching2SP-1Periodic-r17 and srs-ExtensionAperiodicSRS-r17.

[0374] ■ If the terminal reports only srs-AntennaSwitching2SP-1Periodic-r17,

[0375] o The terminal can receive up to two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet from the base station, and can receive up to one SRS resource set with a resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet from the base station, or

[0376] o The terminal can receive up to two SRS resource sets with different resourceType values ​​within the upper layer signaling SRS-ResourceSet from the base station.

[0377] o For the above, two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated simultaneously.

[0378] o For the above, each SRS resource set may include two SRS resources transmitted in different OFDM symbols.

[0379] o For the above, each SRS resource within each SRS resource set can be configured with one SRS port, and the SRS ports of each SRS resource within each SRS resource set can be connected to different terminal antenna ports.

[0380] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position. In this case, the first and second OFDM symbol positions may be different, but the slot positions may be the same or different.

[0381] ■ If the terminal reports only srs-ExtensionAperiodicSRS-r17,

[0382] o The terminal can receive up to two SRS resource sets with a resourceType value of 'aperiodic' (aperiodic) within the upper layer signaling SRS-ResourceSet from the base station, and can receive up to one SRS resource set with a resourceType value of 'periodic' or 'semi-persistent' within the upper layer signaling SRS-ResourceSet from the base station, or

[0383] o The terminal can receive up to two SRS resource sets with different resourceType values ​​within the upper layer signaling SRS-ResourceSet from the base station.

[0384] o For the above, if the terminal receives two SRS resource sets in which the resourceType value is 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station, each SRS resource in the two SRS resource sets can be transmitted in the same or different OFDM symbol positions in two different slots, each SRS resource set can include one SRS resource, each SRS resource in the two SRS resource sets can be configured with one SRS port, and the SRS ports of each SRS resource in the two SRS resource sets can be connected to different terminal antenna ports.

[0385] ㆍ For example, a first SRS resource configured with one SRS port may be included in a first SRS resource set, a second SRS resource configured with one SRS port may be included in a second SRS resource set, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position of a first slot, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position of a second slot. In this case, the first and second OFDM symbol positions may be the same or different within each slot, but the slot positions may be different from each other.

[0386] o For the above, if the terminal receives one SRS resource set in which the resourceType value is 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station, two SRS resources in the SRS resource set can be transmitted at different OFDM symbol positions in the same slot, and each SRS resource in the SRS resource set can be configured with one SRS port, and the SRS port of each SRS resource can be connected to different terminal antenna ports.

[0387] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position within a first slot, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position within the same slot.

[0388] o For the above, if the terminal receives one SRS resource set in which the resourceType value is 'periodic' or 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station, two SRS resources in the SRS resource set can be transmitted at different OFDM symbol positions, each SRS resource in the SRS resource set can be configured with one SRS port, and the SRS port of each SRS resource can be connected to different terminal antenna ports.

[0389] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position within a first slot, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position within the same slot.

[0390] ■ If the terminal does not report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive from the base station up to two different SRS resource sets (for example, 0, 1, or 2) in the upper layer signaling SRS-ResourceSet, where the resourceType value is 'periodic' or 'semi-persistent'. For example, the terminal can receive from the base station one of the following:

[0391] o SRS resource sets with resourceType values ​​of 'periodic' or 'semi-persistent' are not set within the upper layer signaling SRS-ResourceSet.

[0392] o One SRS resource set with the resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet

[0393] o One SRS resource set with the resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet

[0394] o One SRS resource set with a resourceType value of 'periodic' and one SRS resource set with a value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet.

[0395] o For the above, two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated simultaneously.

[0396] o For the above, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with one SRS port, and the SRS port of each SRS resource can be connected to different terminal antenna ports.

[0397] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position within a first slot, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position within the same slot.

[0398] ■ If the terminal reports srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to two SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station, and up to one SRS resource set with a resourceType value of 'periodic' in the upper layer signaling SRS-ResourceSet from the base station.

[0399] o Regarding the above, two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated simultaneously.

[0400] o For the above, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with one SRS port, and the SRS port of each SRS resource can be connected to different terminal antenna ports.

[0401] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position. In this case, the first and second OFDM symbol positions may be different, but the slot positions may be the same or different.

[0402] ■ If the terminal does not report only srs-ExtensionAperiodicSRS-r17, the terminal may receive from the base station at most one (for example, 0 or 1) SRS resource set whose resourceType value is 'aperiodic' in the upper layer signaling SRS-ResourceSet. For example, the terminal may receive from the base station one of the following:

[0403] o SRS resource set with resourceType value of 'aperiodic' is not set within upper layer signaling SRS-ResourceSet

[0404] o One SRS resource set with the resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet

[0405] o For the above, if one SRS resource set is configured, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations within the same slot, and each SRS resource within the SRS resource set can be configured with one SRS port, and the SRS port of each SRS resource can be connected to different terminal antenna ports.

[0406] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position within a first slot, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position within the same slot.

[0407] ■ If the terminal reports only srs-ExtensionAperiodicSRS-r17, the terminal can receive from the base station up to two (for example, 0, 1, or 2) SRS resource sets whose resourceType value is 'aperiodic' in the upper layer signaling SRS-ResourceSet. For example, the terminal can receive from the base station one of the following:

[0408] o SRS resource set with resourceType value of 'aperiodic' is not set within upper layer signaling SRS-ResourceSet

[0409] o One SRS resource set with the resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet

[0410] o Two SRS resource sets with resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet

[0411] o For the above, if one SRS resource set is configured, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations within the same slot, and each SRS resource within the SRS resource set can be configured with one SRS port, and the SRS port of each SRS resource can be connected to different terminal antenna ports.

[0412] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position within a first slot, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position within the same slot.

[0413] o For the above, if two SRS resource sets are configured, each SRS resource in the two SRS resource sets can be transmitted in the same or different OFDM symbol positions in two different slots, each SRS resource set can include one SRS resource, each SRS resource in the two SRS resource sets can be configured with one SRS port, and the SRS ports of each SRS resource in the two SRS resource sets can be connected to different terminal antenna ports.

[0414] ㆍ For example, a first SRS resource configured with one SRS port may be included in a first SRS resource set, a second SRS resource configured with one SRS port may be included in a second SRS resource set, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position of a first slot, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position of a second slot. In this case, the first and second OFDM symbol positions may be the same or different within each slot, but the slot positions may be different from each other.

[0415] - If the terminal does not report both the terminal capability reports srs-AntennaSwitching2SP-1Periodic-r17 and srs-ExtensionAperiodicSRS-r17.

[0416] ■ The terminal can receive up to two SRS resource sets with different resourceType values ​​within the upper layer signaling SRS-ResourceSet from the base station.

[0417] ■ For the above, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with one SRS port, and the SRS port of each SRS resource can be connected to different terminal antenna ports.

[0418] For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and each SRS port of the first and second SRS resources may be connected to different terminal antenna ports, and the SRS port of the first SRS resource may be transmitted at a first OFDM symbol position, and the SRS port of the second SRS resource may be transmitted at a second OFDM symbol position. In this case, the first and second OFDM symbol positions may be different, but the slot positions may be the same or different.

[0419] [2T4R]

[0420] For the 2T4R operation of the terminal, upper layer signaling from the base station for at least one combination of the following items may be set, and operation may be possible accordingly.

[0421] - If the terminal reports some or all of the terminal capability reports srs-AntennaSwitching2SP-1Periodic-r17 and srs-ExtensionAperiodicSRS-r17.

[0422] ■ If the terminal reports only srs-AntennaSwitching2SP-1Periodic-r17,

[0423] o The terminal can receive up to two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet from the base station, and can receive up to one SRS resource set with a resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet from the base station, or

[0424] o The terminal can receive up to two SRS resource sets with different resourceType values ​​within the upper layer signaling SRS-ResourceSet from the base station.

[0425] o For the above, two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated simultaneously.

[0426] o For the above, each SRS resource set may include two SRS resources transmitted in different OFDM symbols.

[0427] o For the above, each SRS resource in each SRS resource set can be configured with two SRS ports, and the two SRS ports of each SRS resource in each SRS resource set can be connected to different terminal antenna ports.

[0428] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of one SRS port, and the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, and the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position, and the first and second OFDM symbol positions may be different from each other within each slot, but may have the same or different slot positions.

[0429] ■ If the terminal reports only srs-ExtensionAperiodicSRS-r17,

[0430] o The terminal can receive up to two SRS resource sets with a resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet from the base station, and can receive up to one SRS resource set with a resourceType value of 'periodic' or 'semi-persistent' within the upper layer signaling SRS-ResourceSet from the base station, or

[0431] o The terminal can receive up to two SRS resource sets with different resourceType values ​​within the upper layer signaling SRS-ResourceSet from the base station.

[0432] o For the above, if the terminal receives two SRS resource sets in which the resourceType value is 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station, each SRS resource in the two SRS resource sets can be transmitted in the same or different OFDM symbol positions in two different slots, each SRS resource set can include one SRS resource, each SRS resource in the two SRS resource sets can be configured with two SRS ports, and the two SRS ports of each SRS resource in the two SRS resource sets can be connected to different terminal antenna ports.

[0433] ㆍ For example, a first SRS resource set may include a first SRS resource composed of two SRS ports, a second SRS resource set may include a second SRS resource composed of two SRS ports, and the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, and the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position of a first slot, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position of a second slot. In this case, the first and second OFDM symbol positions may be the same or different within each slot, but the slot positions may be different from each other.

[0434] o For the above, if the terminal receives one SRS resource set in which the resourceType value is 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station, two SRS resources in the SRS resource set can be transmitted at different OFDM symbol positions in the same slot, and each SRS resource in the SRS resource set can be configured with two SRS ports, and the SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0435] o For the above, if the terminal receives one SRS resource set in which the resourceType value is 'periodic' or 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station, two SRS resources in the SRS resource set can be transmitted at different OFDM symbol positions, each SRS resource in the SRS resource set can be configured with two SRS ports, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0436] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of two SRS ports, and the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, and the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position. In this case, the first and second OFDM symbol positions may be different from each other, but the slot positions may be the same or different from each other.

[0437] ■ If the terminal does not report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive from the base station up to two different SRS resource sets (for example, 0, 1, or 2) in the upper layer signaling SRS-ResourceSet, where the resourceType value is 'periodic' or 'semi-persistent'. For example, the terminal can receive from the base station one of the following:

[0438] o SRS resource sets with resourceType values ​​of 'periodic' or 'semi-persistent' are not set within the upper layer signaling SRS-ResourceSet.

[0439] o One SRS resource set with the resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet

[0440] o One SRS resource set with the resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet

[0441] o One SRS resource set with a resourceType value of 'periodic' and one SRS resource set with a value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet.

[0442] o For the above, two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated simultaneously.

[0443] o For the above, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with two SRS ports, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0444] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of two SRS ports, and the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, and the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position. In this case, the first and second OFDM symbol positions may be different, but the slot positions may be the same or different.

[0445] ■ If the terminal reports srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet from the base station, and up to one SRS resource set with a resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet from the base station.

[0446] o Regarding the above, two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated simultaneously.

[0447] o For the above, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with two SRS ports, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0448] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of two SRS ports, and the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, and the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position. In this case, the first and second OFDM symbol positions may be different, but the slot positions may be the same or different.

[0449] ■ If the terminal does not report srs-ExtensionAperiodicSRS-r17, the terminal may receive from the base station at most one (for example, 0 or 1) SRS resource set whose resourceType value is 'aperiodic' in the upper layer signaling SRS-ResourceSet. For example, the terminal may receive from the base station one of the following:

[0450] o SRS resource set with resourceType value of 'aperiodic' is not set within upper layer signaling SRS-ResourceSet

[0451] o One SRS resource set with the resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet

[0452] o For the above, if one SRS resource set is configured, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations within the same slot, and each SRS resource within the SRS resource set can be configured with two SRS ports, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0453] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of two SRS ports, the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position within a first slot, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position within the same slot.

[0454] ■ If the terminal reports srs-ExtensionAperiodicSRS-r17, the terminal can receive from the base station up to two (for example, 0, 1, or 2) SRS resource sets whose resourceType value is 'aperiodic' in the upper layer signaling SRS-ResourceSet. For example, the terminal can receive from the base station one of the following:

[0455] o SRS resource set with resourceType value of 'aperiodic' is not set within upper layer signaling SRS-ResourceSet

[0456] o One SRS resource set with the resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet

[0457] o Two SRS resource sets with resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet

[0458] o For the above, if one SRS resource set is configured, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations within the same slot, and each SRS resource within the SRS resource set can be configured with two SRS ports, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0459] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of two SRS ports, the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position within a first slot, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position within the same slot.

[0460] o For the above, if two SRS resource sets are configured, each SRS resource in the two SRS resource sets can be transmitted in the same or different OFDM symbol positions in two different slots, each SRS resource set can include one SRS resource, each SRS resource in the two SRS resource sets can be configured with two SRS ports, and the two SRS ports of each SRS resource in the two SRS resource sets can be connected to different terminal antenna ports.

[0461] ㆍ For example, a first SRS resource set may include a first SRS resource composed of two SRS ports, a second SRS resource set may include a second SRS resource composed of two SRS ports, and the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, and the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position of a first slot, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position of a second slot. In this case, the first and second OFDM symbol positions may be the same or different within each slot, but the slot positions may be different from each other.

[0462] - If the terminal does not report both the terminal capability reports srs-AntennaSwitching2SP-1Periodic-r17 and srs-ExtensionAperiodicSRS-r17.

[0463] ■ The terminal can receive up to two SRS resource sets with different resourceType values ​​within the upper layer signaling SRS-ResourceSet from the base station.

[0464] o For the above, each SRS resource set can include two SRS resources, and the two SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with two SRS ports, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0465] ㆍ For example, the SRS resource set may include first and second SRS resources each consisting of two SRS ports, and the two SRS ports of the first and second SRS resources may be connected to different terminal antenna ports, and the two SRS ports of the first SRS resource may be transmitted at a first OFDM symbol position, and the two SRS ports of the second SRS resource may be transmitted at a second OFDM symbol position. In this case, the first and second OFDM symbol positions may be different, but the slot positions may be the same or different.

[0466] [1T4R]

[0467] For the 1T4R operation of the terminal, upper layer signaling from the base station for at least one combination of the following items may be set, and operation may be possible accordingly.

[0468] - If the terminal reports some or all of the terminal capability reports srs-AntennaSwitching2SP-1Periodic-r17, srs-ExtensionAperiodicSRS-r17, and srs-OneAP-SRS-r17.

[0469] ■ If the terminal does not report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive from the base station at most one (for example, 0 or 1) SRS resource set whose resourceType value is 'periodic' or 'semi-persistent' in the upper layer signaling SRS-ResourceSet. For example, the terminal can receive from the base station one of the following:

[0470] o SRS resource set with resourceType value of 'periodic' or 'semi-persistent' is not set within upper layer signaling SRS-ResourceSet

[0471] o One SRS resource set with the resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet

[0472] o One SRS resource set with the resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet

[0473] o For the above, each SRS resource set can include four SRS resources, and the four SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with one SRS port, and one SRS port of each SRS resource can be connected to different terminal antenna ports.

[0474] ㆍ For example, the SRS resource set may include first to fourth SRS resources each consisting of one SRS port, one SRS port of the first to fourth SRS resources may be connected to a different terminal antenna port, and one SRS port of the first to fourth SRS resources may be transmitted at the first to fourth OFDM symbol positions, and the first to fourth OFDM symbol positions may be different from each other, but the slot positions may be the same or different from each other.

[0475] ■ If the terminal reports srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet from the base station, and up to one SRS resource set with a resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet from the base station.

[0476] o Regarding the above, two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated simultaneously.

[0477] o For the above, each SRS resource set can include four SRS resources, and the four SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with one SRS port, and one SRS port of each SRS resource can be connected to different terminal antenna ports.

[0478] ㆍ For example, the SRS resource set may include first to fourth SRS resources each consisting of one SRS port, one SRS port of the first to fourth SRS resources may be connected to a different terminal antenna port, and one SRS port of the first to fourth SRS resources may be transmitted at the first to fourth OFDM symbol positions, and the first to fourth OFDM symbol positions may be different from each other, but the slot positions may be the same or different from each other.

[0479] ■ Depending on whether the terminal reports srs-ExtensionAperiodicSRS-r17 or srs-OneAP-SRS-r17 as a terminal capability report, the following upper layer signaling settings of the base station and terminal behavior can be expected.

[0480] o If the terminal does not report both srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17, the terminal may receive 0 or 2 SRS resource sets with a resourceType value of 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station.

[0481] o If the terminal reports both srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17, the terminal can receive 0, 1, 2, or 4 SRS resource sets with resourceType value of 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station.

[0482] o If the terminal reports only srs-ExtensionAperiodicSRS-r17 among srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17, the terminal can receive 0, 2, or 4 SRS resource sets with a resourceType value of 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station.

[0483] o If the terminal reports only srs-OneAP-SRS-r17 among srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17, the terminal can receive 0, 1, or 2 SRS resource sets with a resourceType value of 'aperiodic' in SRS-ResourceSet, which is an upper layer signaling from the base station.

[0484] o For the above, if one SRS resource set is configured, each SRS resource set can include four SRS resources, and the four SRS resources can be transmitted at different OFDM symbol locations within the same slot, and each SRS resource within the SRS resource set can be configured with one SRS port, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0485] ㆍ For example, the SRS resource set may include first to fourth SRS resources each consisting of one SRS port, one SRS port of the first to fourth SRS resources may be connected to a different terminal antenna port, and one SRS port of the first to fourth SRS resources may be transmitted at the first to fourth OFDM symbol positions within the same slot, and the first to fourth OFDM symbol positions may be different from each other.

[0486] o For the above, if two SRS resource sets are set,

[0487] ㆍ Each SRS resource set may contain two SRS resources, or the first SRS resource set may have one SRS resource and the second SRS resource set may have three SRS resources.

[0488] ㆍ Each SRS resource within each SRS resource set can be transmitted at different OFDM symbol locations within the same slot, and SRS transmission for each SRS resource set can be performed at different slots. When transmitting SRS between different SRS resources within different SRS resource sets, transmission can be at the same or different OFDM symbol locations, but the slot locations can be different.

[0489] ㆍ Each SRS resource can be composed of one SRS port, and one SRS port of each SRS resource can be connected to different terminal antenna ports.

[0490] ㆍ For example, the first and second SRS resources, each configured with one SRS port, may be included in the first SRS resource set, and the third and fourth SRS resources, each configured with one SRS port, may be included in the second SRS resource set. One SRS port of the first to fourth SRS resources may be connected to a different terminal antenna port. One SRS port of each of the first and second SRS resources may be transmitted at the first and second OFDM symbol positions within any same slot, and the first and second OFDM symbol positions may be different from each other. One SRS port of each of the third and fourth SRS resources may be transmitted at the third and fourth OFDM symbol positions within a different slot from that in which the first and second SRS resources are transmitted, and the third and fourth OFDM symbol positions may be different from each other. At this time, the first OFDM symbol position and the third and fourth OFDM symbol positions may be the same as or different from each other, and similarly, the second OFDM symbol position may also be the same as or different from the third and fourth OFDM symbol positions.

[0491] ㆍ As another example, a first SRS resource configured with one SRS port may be included in a first SRS resource set, and second to fourth SRS resources, each configured with one SRS port, may be included in a second SRS resource set. One SRS port of the first to fourth SRS resources may be connected to a different terminal antenna port. One SRS port of the first SRS resource may be transmitted at a first OFDM symbol position within an arbitrary slot. One SRS port of each of the second to fourth SRS resources may be transmitted at a second to fourth OFDM symbol position within a slot different from that in which the first SRS resource is transmitted, and the second and fourth OFDM symbol positions may be different from each other. In this case, the first OFDM symbol position and the second to fourth OFDM symbol positions may be the same or different from each other.

[0492] o For the above, if four SRS resource sets are configured, each SRS resource set can include one SRS resource, and the four SRS resources can be transmitted in the same or different OFDM symbol positions within each slot, and SRS transmission for each SRS resource set can be performed in different slots. Each SRS resource within the SRS resource set can be configured with one SRS port, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0493] ㆍ For example, the first to fourth SRS resources may be included in the first to fourth SRS resource sets, respectively (i.e., one SRS resource is included in one SRS resource set), one SRS port of the first to fourth SRS resources may be connected to a different terminal antenna port, and one SRS port of the first to fourth SRS resources may be transmitted at the first to fourth OFDM symbol positions in different slots, and the first to fourth OFDM symbol positions in each slot may be the same or different, but the slot positions may be different.

[0494] - If the terminal does not report all of the terminal capability reports srs-AntennaSwitching2SP-1Periodic-r17, srs-ExtensionAperiodicSRS-r17, and srs-OneAP-SRS-r17, i.e., does not report all three terminal capabilities,

[0495] ■ The terminal can receive up to one (i.e. 0 or 1) SRS resource set with a resourceType value of 'periodic' or 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station.

[0496] o For the above, each SRS resource set can include four SRS resources, and the four SRS resources can be transmitted at different OFDM symbol locations, and each SRS resource within the SRS resource set can be configured with one SRS port, and one SRS port of each SRS resource can be connected to different terminal antenna ports.

[0497] ㆍ For example, the SRS resource set may include first to fourth SRS resources each consisting of one SRS port, one SRS port of the first to fourth SRS resources may be connected to a different terminal antenna port, and one SRS port of the first to fourth SRS resources may be transmitted at the first to fourth OFDM symbol positions, and the first to fourth OFDM symbol positions may be different from each other, but the slot positions may be the same or different from each other.

[0498] ■ The terminal can receive 0 or 2 SRS resource sets with a resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet from the base station. If 2 SRS resource sets are set, some or all of the following may be considered.

[0499] o Each SRS resource set may contain two SRS resources, or the first SRS resource set may have one SRS resource and the second SRS resource set may have three SRS resources.

[0500] o Each SRS resource within each SRS resource set can be transmitted in different OFDM symbol locations within the same slot, and SRS transmission for each SRS resource set can be performed in different slots. When transmitting SRS between different SRS resources in different SRS resource sets, transmission can be in the same or different OFDM symbol locations, but the slot locations can be different.

[0501] o Each SRS resource can be composed of one SRS port, and one SRS port of each SRS resource can be connected to different terminal antenna ports.

[0502] o For example, a first and a second SRS resource each configured with one SRS port may be included in a first SRS resource set, and a third and a fourth SRS resource each configured with one SRS port may be included in a second SRS resource set. One SRS port of the first to fourth SRS resources may be connected to a different terminal antenna port. One SRS port of each of the first and second SRS resources may be transmitted at the first and second OFDM symbol positions within any same slot, and the first and second OFDM symbol positions may be different from each other. One SRS port of each of the third and fourth SRS resources may be transmitted at the third and fourth OFDM symbol positions within a different slot from that in which the first and second SRS resources are transmitted, and the third and fourth OFDM symbol positions may be different from each other. At this time, the first OFDM symbol position and the third and fourth OFDM symbol positions may be the same as or different from each other, and similarly, the second OFDM symbol position may also be the same as or different from the third and fourth OFDM symbol positions.

[0503] o As another example, a first SRS resource set may include a first SRS resource configured with one SRS port, and a second to fourth SRS resources each configured with one SRS port may be included in a second SRS resource set. One SRS port of each of the first to fourth SRS resources may be connected to a different terminal antenna port. One SRS port of the first SRS resource may be transmitted at a first OFDM symbol position within an arbitrary slot. Each of the second to fourth SRS resources may be transmitted at a second to fourth OFDM symbol position within a different slot from that in which the first SRS resource is transmitted, and the second and fourth OFDM symbol positions may be different from each other. In this case, the first OFDM symbol position and the second to fourth OFDM symbol positions may be the same or different from each other.

[0504] - For the above, if multiple SRS resource sets are set (for example, if 2 or 4 SRS resource sets are set)

[0505] ■ The terminal can expect that the values ​​of p0, alpha, pathlossReferenceRS, and srs-PowerControlAdjustmentStates, which are power control parameters that can be set by upper layer signaling within each SRS resource set from the base station, are set to the same value for all SRS resource sets. In other words, it can be expected that all multiple SRS resource sets have the same power control parameters. Such constraints can be described later as [Power Control Parameter Constraints].

[0506] o The above [power control parameter constraints] can be applied only to SRS resource sets for which the terminal has received the resourceType value set to 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station.

[0507] o The above [power control parameter constraints] can be applied to SRS resource sets for which the value of resourceType is set to 'periodic', 'semi-persistent', or 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station.

[0508] ■ The terminal can expect that the aperiodicSRS-ResourceTrigger value, which is a higher layer signaling from the base station, or the value of one entry in the AperiodicSRS-ResourceTriggerList, which is a higher layer signaling, is set to the same value for all SRS resource sets. Such restrictions can be described later as [Aperiodic SRS Trigger Restrictions].

[0509] o At this time, aperiodicSRS-ResourceTrigger, which is an upper layer signaling set in the SRS resource set from the base station, means aperiodic SRS trigger state information, and if the terminal receives an aperiodic SRS trigger for a specific aperiodic SRS trigger state from the base station through DCI, and the value set in aperiodicSRS-ResourceTrigger, which is an upper layer signaling, is an aperiodic SRS trigger state indicated by the DCI, the terminal can perform aperiodic SRS transmission for the SRS resource set.

[0510] o Similarly, AperiodicSRS-ResourceTriggerList, which is an upper layer signaling set in an SRS resource set from a base station, includes information on multiple aperiodic SRS trigger states, and if a terminal receives an aperiodic SRS trigger for a specific aperiodic SRS trigger state from the base station through DCI, and if the aperiodic SRS trigger state indicated by the DCI is included among multiple values ​​set in AperiodicSRS-ResourceTriggerList, which is an upper layer signaling, the terminal can perform aperiodic SRS transmission for the corresponding SRS resource set.

[0511] o While the upper layer signaling, aperiodicSRS-ResourceTrigger, provided the ability for the corresponding SRS resource set to be included in one aperiodic SRS trigger state, the upper layer signaling, AperiodicSRS-ResourceTriggerList, provides the ability for the corresponding SRS resource set to be included in multiple aperiodic SRS trigger states, which may increase the possibility that the corresponding SRS resource set can be triggered from the base station.

[0512] o The above [aperiodic SRS trigger constraints] can be applied only to SRS resource sets for which the terminal has received the resourceType value set to 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station.

[0513] ■ The terminal can expect the slotOffset, which is the upper layer signaling within each SRS resource set from the base station, to have different values. Such restrictions can be described later as [Slot Offset Specifications].

[0514] o The above [slot offset information] can be applied only to SRS resource sets for which the terminal has received the resourceType value set to 'aperiodic' in the upper layer signaling SRS-ResourceSet from the base station.

[0515] [1T1R, 2T2R, 4T4R]

[0516] For the 1T1R, 2T2R, and 4T4R operations of the terminal, upper layer signaling from the base station for at least one combination of the following items may be set, and operations may be performed accordingly.

[0517] - If the terminal does not report the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to two SRS resource sets from the base station.

[0518] - If the terminal reports the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive the following upper layer signaling settings from the base station.

[0519] ■ Two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet, and one SRS resource set with a resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet.

[0520] o Regarding the above, two SRS resource sets with a resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated simultaneously.

[0521] ■ Up to 2 SRS resource sets

[0522] - Each SRS resource set contains one SRS resource, and for 1T1R, 2T2R, and 4T4R, the number of SRS ports set for each SRS resource can be 1, 2, and 4, respectively.

[0523] - For 1T1R, 2T2R, and 4T4R, the terminal may not expect SRS transmissions for two or more SRS resource sets with upper layer signaling usage set to 'antennaSwitching' to be set or triggered at the same OFDM symbol position.

[0524] [1T6R]

[0525] For the 1T6R operation of the terminal, upper layer signaling from the base station for at least one combination of the following items may be set, and operation may be possible accordingly.

[0526] - A terminal can receive up to one (i.e., 0 or 1) SRS resource set in which the resourceType value is 'periodic' within the upper layer signaling SRS-ResourceSet from the base station, and one SRS resource set can include six SRS resources, and each SRS resource can be configured with one SRS port, and each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0527] - The terminal can receive the settings for the SRS resource set whose resourceType value is 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station as follows.

[0528] ■ If the terminal does not report the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to one (i.e., 0 or 1) SRS resource set with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station.

[0529] ■ If the terminal reports srs-AntennaSwitching2SP-1Periodic-r17, which is a terminal capability report, the terminal can receive up to two (i.e., 0, 1, or 2) SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station, and two SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet may not be activated at the same time.

[0530] ■ One SRS resource set can include six SRS resources, each SRS resource can be composed of one SRS port, each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0531] - The terminal can receive up to three SRS resource sets (i.e., 0, 1, 2, or 3) whose resourceType value is 'aperiodic' within the upper layer signaling SRS-ResourceSet from the base station.

[0532] ■ If one SRS resource set is configured, six SRS resources can be included, each SRS resource can be configured with one SRS port, each SRS resource can be transmitted at a different OFDM symbol location within the same slot, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0533] ■ If two SRS resource sets are configured, a total of six SRS resources can be divided and included in the two SRS resource sets, each SRS resource can be configured with one SRS port, all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0534] o For example, the terminal may include first to third SRS resources in a first SRS resource set, and fourth to sixth SRS resources in a second SRS resource set. Transmission for the first to third SRS resources in the first SRS resource set may be performed in the first to third OFDM symbol positions in the first slot, and the first to third OFDM symbol positions may be different from each other. Transmission for the fourth to sixth SRS resources in the second SRS resource set may be performed in the fourth to sixth OFDM symbol positions in the second slot, and the fourth to sixth OFDM symbol positions may be different from each other. In this case, the first and second slot positions may be different from each other, and the first to third OFDM symbol positions and the fourth to sixth OFDM symbol positions may be the same or different from each other.

[0535] o As another example, it may be possible for the first and second SRS resource sets to each include one (e.g., the first SRS resource) and five (e.g., the second to sixth SRS resources) SRS resources, and other combinations may not be excluded.

[0536] ■ If three SRS resource sets are configured, a total of six SRS resources can be divided and included in the three SRS resource sets, and each SRS resource can be configured with one SRS port, and all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, and SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0537] o For example, the terminal may include first and second SRS resources in a first SRS resource set, third and fourth SRS resources in a second SRS resource set, and fifth and sixth SRS resources in a third SRS resource set. Transmissions for the first and second SRS resources in the first SRS resource set may be performed at first and second OFDM symbol positions in a first slot, and the first and second OFDM symbol positions may be different from each other. Transmissions for the third and fourth SRS resources in the second SRS resource set may be performed at third and fourth OFDM symbol positions in a second slot, and the third and fourth OFDM symbol positions may be different from each other. Transmissions for the fifth and sixth SRS resources in the third SRS resource set may be performed at fifth and sixth OFDM symbol positions in a third slot, and the fifth and sixth OFDM symbol positions may be different from each other. At this time, the first, second, and third slot positions may be different from each other, and the first and second OFDM symbol positions, the third and fourth OFDM symbol positions, and the fifth and sixth OFDM symbol positions may be the same or different from each other.

[0538] o As another example, it may be possible for the first, second, and third SRS resource sets to each include three (e.g., the first to third SRS resources), two (e.g., the fourth and fifth SRS resources), and one (e.g., the sixth SRS resource) SRS resources, and other combinations may not be excluded.

[0539] [1T8R]

[0540] For the 1T8R operation of the terminal, upper layer signaling from the base station for at least one combination of the following items may be set, and operation may be possible accordingly.

[0541] - A terminal can receive up to one (i.e., 0 or 1) SRS resource set in which the resourceType value is 'periodic' within the upper layer signaling SRS-ResourceSet from the base station, and one SRS resource set can include eight SRS resources, and each SRS resource can be configured with one SRS port, and each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0542] - The terminal can receive the settings for the SRS resource set whose resourceType value is 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station as follows.

[0543] ■ If the terminal does not report the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to one (i.e., 0 or 1) SRS resource set with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station.

[0544] ■ If the terminal reports the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to two (i.e., 0, 1, or 2) SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station, and two SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet may not be activated at the same time.

[0545] ■ One SRS resource set can include eight SRS resources, each SRS resource can be composed of one SRS port, each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0546] - The terminal can receive 0, 2, 3, or 4 SRS resource sets with a resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet from the base station.

[0547] ■ If two SRS resource sets are configured, a total of eight SRS resources can be divided and included in the two SRS resource sets, each SRS resource can be configured with one SRS port, all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0548] o For example, the terminal may include the first to fourth SRS resources in the first SRS resource set, and the fifth to eighth SRS resources in the second SRS resource set. Transmission for the first to fourth SRS resources in the first SRS resource set may be performed in the first to fourth OFDM symbol positions in the first slot, and the first to fourth OFDM symbol positions may be different from each other. Transmission for the fifth to eighth SRS resources in the second SRS resource set may be performed in the fifth to eighth OFDM symbol positions in the second slot, and the fifth to eighth OFDM symbol positions may be different from each other. In this case, the first and second slot positions may be different from each other, and the first to fourth OFDM symbol positions and the fifth to eighth OFDM symbol positions may be the same or different from each other.

[0549] o As another example, it may be possible for the first and second SRS resource sets to each include one (e.g., the first SRS resource) and seven (e.g., the second to eighth SRS resources) SRS resources, and other combinations may not be excluded.

[0550] ■ If three SRS resource sets are configured, a total of eight SRS resources can be divided and included in the three SRS resource sets, and each SRS resource can be configured with one SRS port, and all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, and SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and one SRS port of each SRS resource can be connected to a different terminal antenna port.

[0551] o For example, the terminal may include the first to third SRS resources in the first SRS resource set, the fourth to sixth SRS resources in the second SRS resource set, and the seventh and eighth SRS resources in the third SRS resource set. Transmission for the first to third SRS resources in the first SRS resource set may be performed in the first to third OFDM symbol positions in the first slot, and the first to third OFDM symbol positions may be different from each other. Transmission for the fourth to sixth SRS resources in the second SRS resource set may be performed in the fourth to sixth OFDM symbol positions in the second slot, and the fourth to sixth OFDM symbol positions may be different from each other. Transmission for the seventh and eighth SRS resources in the third SRS resource set may be performed in the seventh and eighth OFDM symbol positions in the third slot, and the seventh and eighth OFDM symbol positions may be different from each other. At this time, the first, second, and third slot positions may be different from each other, and the first to third OFDM symbol positions, the fourth to sixth OFDM symbol positions, and the seventh and eighth OFDM symbol positions may be the same or different from each other.

[0552] o As another example, it may be possible for the first, second, and third SRS resource sets to each include four (e.g., the first to fourth SRS resources), two (e.g., the fifth and sixth SRS resources), and two (e.g., the seventh and eighth SRS resources), and other combinations may not be excluded.

[0553] ■ If 4 SRS resource sets are configured, a total of 8 SRS resources can be divided and included in the 4 SRS resource sets, and each SRS resource can be configured with 1 SRS port, and all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, and SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and 1 SRS port of each SRS resource can be connected to a different terminal antenna port.

[0554] o For example, the terminal may include first and second SRS resources in a first SRS resource set, third and fourth SRS resources in a second SRS resource set, fifth and sixth SRS resources in a third SRS resource set, and seventh and eighth SRS resources in a fourth SRS resource set. Transmissions for the first and second SRS resources in the first SRS resource set may be performed at first and second OFDM symbol positions in a first slot, and the first and second OFDM symbol positions may be different from each other. Transmissions for the third and fourth SRS resources in the second SRS resource set may be performed at third and fourth OFDM symbol positions in a second slot, and the third and fourth OFDM symbol positions may be different from each other. Transmissions for the fifth and sixth SRS resources in the third SRS resource set may be performed at fifth and sixth OFDM symbol positions in a third slot, and the fifth and sixth OFDM symbol positions may be different from each other. Transmission for the 7th and 8th SRS resources within the 4th SRS resource set can be performed in the 7th and 8th OFDM symbol positions in the 4th slot, and the 7th and 8th OFDM symbol positions can be different from each other. In this case, the 1st to 4th slot positions can be different from each other, and the 1st and 2nd OFDM symbol positions, the 3rd and 4th OFDM symbol positions, the 5th and 6th OFDM symbol positions, and the 7th and 8th OFDM symbol positions can be the same or different from each other.

[0555] o As another example, it may be possible for the first, second, third, and fourth SRS resource sets to each include three (e.g., the first to third SRS resources), two (e.g., the fourth and fifth SRS resources), two (e.g., the sixth and seventh SRS resources), and one (e.g., the eighth SRS resource) SRS resources, and other combinations may not be excluded.

[0556] [2T6R]

[0557] For the 2T6R operation of the terminal, upper layer signaling from the base station for at least one combination of the following items may be set, and operation may be possible accordingly.

[0558] - A terminal can receive at most one (i.e., 0 or 1) SRS resource set in which the resourceType value is 'periodic' within the upper layer signaling SRS-ResourceSet from the base station, and one SRS resource set can include three SRS resources, and each SRS resource can be composed of two SRS ports, and each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0559] - The terminal can receive the settings for the SRS resource set whose resourceType value is 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station as follows.

[0560] ■ If the terminal does not report the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to one (i.e., 0 or 1) SRS resource set with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station.

[0561] ■ If the terminal reports srs-AntennaSwitching2SP-1Periodic-r17, which is a terminal capability report, the terminal can receive up to two (i.e., 0, 1, or 2) SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station, and two SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet may not be activated at the same time.

[0562] ■ One SRS resource set can include three SRS resources, each SRS resource can be composed of two SRS ports, each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0563] - The terminal can receive up to three SRS resource sets (i.e., 0, 1, 2, or 3) whose resourceType value is 'aperiodic' within the upper layer signaling SRS-ResourceSet from the base station.

[0564] ■ If one SRS resource set is configured, three SRS resources can be included, each SRS resource can be composed of two SRS ports, each SRS resource can be transmitted at different OFDM symbol locations within the same slot, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0565] ■ If two SRS resource sets are configured, a total of three SRS resources can be divided and included in the two SRS resource sets, each SRS resource can be composed of two SRS ports, all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0566] o For example, the terminal may include first and second SRS resources in the first SRS resource set, and may include third SRS resources in the second SRS resource set. Transmission for the first and second SRS resources in the first SRS resource set may be performed in the first and second OFDM symbol positions in the first slot, and the first and second OFDM symbol positions may be different from each other. Transmission for the third SRS resource in the second SRS resource set may be performed in the third OFDM symbol position in the second slot. In this case, the first and second slot positions may be different from each other, and the first and second OFDM symbol positions and the third OFDM symbol positions may be the same or different from each other.

[0567] o As another example, it may be possible for the first and second SRS resource sets to contain one (e.g., the first SRS resource) and two (e.g., the second and third SRS resources) SRS resources, respectively, and other combinations may not be excluded.

[0568] ■ If three SRS resource sets are configured, a total of three SRS resources can be divided and included in the three SRS resource sets, each SRS resource can be composed of two SRS ports, all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0569] o For example, the terminal may include a first SRS resource in a first SRS resource set, a second SRS resource in a second SRS resource set, and a third SRS resource in a third SRS resource set. Transmission for the first SRS resource in the first SRS resource set may be performed at a first OFDM symbol position in a first slot. Transmission for the second SRS resource in the second SRS resource set may be performed at a second OFDM symbol position in a second slot. Transmission for the third SRS resource in the third SRS resource set may be performed at a third OFDM symbol position in a third slot. In this case, the first, second, and third slot positions may be different from each other, and the first to third OFDM symbol positions may be the same or different from each other.

[0570] [2T8R]

[0571] For the 2T8R operation of the terminal, upper layer signaling from the base station for at least one combination of the following items may be set, and operation may be possible accordingly.

[0572] - A terminal can receive up to one (i.e., 0 or 1) SRS resource set in which the resourceType value is 'periodic' within the upper layer signaling SRS-ResourceSet from the base station, and one SRS resource set can include four SRS resources, and each SRS resource can be composed of two SRS ports, and each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0573] - The terminal can receive the settings for the SRS resource set whose resourceType value is 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station as follows.

[0574] ■ If the terminal does not report the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to one (i.e., 0 or 1) SRS resource set with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station.

[0575] ■ If the terminal reports the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive up to two (i.e., 0, 1, or 2) SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet from the base station, and two SRS resource sets with a resourceType value of 'semi-persistent' in the upper layer signaling SRS-ResourceSet may not be activated at the same time.

[0576] ■ One SRS resource set can include four SRS resources, each SRS resource can be composed of two SRS ports, each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0577] - The terminal can receive 0, 2, 3, or 4 SRS resource sets with a resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet from the base station.

[0578] ■ If one SRS resource set is configured, four SRS resources can be included, each SRS resource can be composed of two SRS ports, each SRS resource can be transmitted at different OFDM symbol locations within the same slot, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0579] ■ If two SRS resource sets are configured, a total of four SRS resources can be divided and included in the two SRS resource sets, each SRS resource can be composed of two SRS ports, all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0580] o For example, the terminal may include first and second SRS resources in the first SRS resource set, and third and fourth SRS resources in the second SRS resource set. Transmission for the first and second SRS resources in the first SRS resource set may be performed in the first and second OFDM symbol positions in the first slot, and the first and second OFDM symbol positions may be different from each other. Transmission for the third and fourth SRS resources in the second SRS resource set may be performed in the third and fourth OFDM symbol positions in the second slot, and the third and fourth OFDM symbol positions may be different from each other. In this case, the first and second slot positions may be different from each other, and the first and second OFDM symbol positions and the third and fourth OFDM symbol positions may be the same or different from each other.

[0581] o As another example, it may be possible for the first and second SRS resource sets to include one (e.g., the first SRS resource) and three (e.g., the second to fourth SRS resources) SRS resources, respectively, and other combinations may not be excluded.

[0582] ■ If three SRS resource sets are configured, a total of four SRS resources can be divided and included in the three SRS resource sets, and each SRS resource can be composed of two SRS ports, and all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, and SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and the two SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0583] o For example, the terminal may include first and second SRS resources in a first SRS resource set, a third SRS resource in a second SRS resource set, and a fourth SRS resource in a third SRS resource set. Transmission for the first and second SRS resources in the first SRS resource set may be performed at first and second OFDM symbol positions in a first slot, and the first and second OFDM symbol positions may be different from each other. Transmission for the third SRS resource in the second SRS resource set may be performed at a third OFDM symbol position in a second slot. Transmission for the fourth SRS resource in the third SRS resource set may be performed at a fourth OFDM symbol position in a third slot. In this case, the first, second, and third slot positions may be different from each other, and the first to fourth OFDM symbol positions may be the same or different from each other.

[0584] o As another example, it may be possible for the first, second, and third SRS resource sets to each include one (e.g., the first SRS resource), two (e.g., the second and third SRS resources), and one (e.g., the fourth SRS resource) SRS resource, and other combinations may not be excluded.

[0585] ■ If 4 SRS resource sets are configured, a total of 4 SRS resources can be divided and included in the 4 SRS resource sets, each SRS resource can be composed of 2 SRS ports, all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and the 2 SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0586] o For example, the terminal may include first, second, third, and fourth SRS resources within the first, second, third, and fourth SRS resource sets, respectively, and transmissions for the first, second, third, and fourth SRS resources within the first, second, third, and fourth SRS resource sets, respectively, may be performed at first, second, third, and fourth OFDM symbol positions in first, second, third, and fourth slots, respectively, and the first to fourth slot positions may be different from each other, and the first to fourth OFDM symbol positions may be the same or different from each other.

[0587] [4T8R]

[0588] For the 4T8R operation of the terminal, upper layer signaling from the base station can be set for at least one combination of the following items, and operation can be performed accordingly.

[0589] - If the terminal does not report the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17,

[0590] ■ The terminal can receive up to two different SRS resource sets (e.g., 0, 1, or 2) from the base station, where the resourceType value is 'periodic' or 'semi-persistent' in the upper layer signaling SRS-ResourceSet. For example, the terminal can receive one of the following from the base station.

[0591] o SRS resource sets with resourceType values ​​of 'periodic' or 'semi-persistent' are not set within the upper layer signaling SRS-ResourceSet.

[0592] o One SRS resource set with the resourceType value of 'periodic' within the upper layer signaling SRS-ResourceSet

[0593] o One SRS resource set with the resourceType value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet

[0594] o One SRS resource set with a resourceType value of 'periodic' and one SRS resource set with a value of 'semi-persistent' within the upper layer signaling SRS-ResourceSet.

[0595] o For the above, each SRS resource set can include two SRS resources, each SRS resource can be composed of four SRS ports, each SRS resource can be transmitted at different OFDM symbol locations within the same or different slots, and the four SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0596] - If the terminal reports the terminal capability report srs-AntennaSwitching2SP-1Periodic-r17, the terminal can receive from the base station up to two (i.e., 0, 1, or 2) SRS resource sets whose resourceType value is 'semi-persistent' within the upper layer signaling SRS-ResourceSet, and up to one (i.e., 0 or 1) SRS resource set whose resourceType value is 'periodic' within the upper layer signaling SRS-ResourceSet, and two SRS resource sets whose resourceType value is 'semi-persistent' within the upper layer signaling SRS-ResourceSet may not be activated at the same time.

[0597] ■ Each SRS resource set can include two SRS resources, each SRS resource can be composed of four SRS ports, each SRS resource can be transmitted at a different OFDM symbol location within the same or different slots, and the four SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0598] - The terminal can receive 0, 1, or 2 SRS resource sets with a resourceType value of 'aperiodic' within the upper layer signaling SRS-ResourceSet from the base station.

[0599] ■ If one SRS resource set is configured, two SRS resources can be included, each SRS resource can be composed of four SRS ports, each SRS resource can be transmitted at different OFDM symbol locations within the same slot, and the four SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0600] ■ If two SRS resource sets are configured, a total of two SRS resources can be divided and included in the two SRS resource sets, and each SRS resource can be composed of four SRS ports, and all SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same slot, and SRS transmission for different SRS resource sets can be performed at the same or different OFDM symbol locations in different slots, and the four SRS ports of each SRS resource can be connected to different terminal antenna ports.

[0601] For example, the terminal may include first and second SRS resources in the first and second SRS resource sets, respectively, and transmission for the first and second SRS resources in the first and second SRS resource sets may be performed in the first and second OFDM symbol positions in the first and second slots, respectively. In this case, the first and second slot positions may be different from each other, and the first and second OFDM symbol positions may be the same or different from each other.

[0602] 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 38] below.

[0603] [Table 38]

[0604]

[0605] In [Table 38], 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 38], 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.

[0606] 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.

[0607] As another example, if a terminal has two SRS resource sets configured 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 38] 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.

[0608] - 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.

[0609] - 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.

[0610] 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.

[0611] 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.

[0612] 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.

[0613] FIG. 7 is a diagram illustrating an SRS antenna switching operation according to one embodiment of the present disclosure.

[0614] The terminal represents a situation in which it operates in 1T4R, and may be configured with two aperiodic SRS resource sets (e.g., SRS resource sets #0 and #1). The terminal receives a PDCCH from a base station (700), and may be instructed to trigger aperiodic SRS for SRS resource set #0 (710) and SRS resource set #1 (720) through the PDCCH. At this time, the slot offset value for SRS resource set #0 (710) 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 (720) 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 later than the slot in which the PDCCH is received (i.e., at slot #2).

[0615] SRS resource #0 (711) and SRS resource #1 (712) included in SRS resource set #0 (710) are transmitted at different OFDM symbol positions within slot #1, and at this time, Y number of OFDM symbols may exist as a guard interval between SRS resources #0 and #1 (713). In addition, when transmitting for SRS resource #0 (730), the terminal can perform SRS transmission by connecting one SRS port to the first receiving antenna port (735) of the terminal, and when transmitting for SRS resource #1 (740), the terminal can perform SRS transmission by connecting one SRS port to the second receiving antenna port (745) of the terminal.

[0616] SRS resource #2 (721) and SRS resource #3 (722) included in SRS resource set #1 (720) 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 (723). In addition, when transmitting for SRS resource #2 (750), the terminal can perform SRS transmission by connecting one SRS port to the third receiving antenna port (755) of the terminal, and when transmitting for SRS resource #3 (760), the terminal can perform SRS transmission by connecting one SRS port to the fourth receiving antenna port (765) of the terminal.

[0617] 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.

[0618] [Regarding terminal capability reporting]

[0619] 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.

[0620] 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.

[0621] 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.

[0622] 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.

[0623] 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.

[0624] 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."

[0625] 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 according to the preset rat-Type order (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.

[0626] 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.

[0627] 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.

[0628] 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).

[0629] In the present disclosure, when determining whether cooperative communication is applied, the terminal may use various methods, such as having a specific format for the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied, or including a specific indicator that indicates whether cooperative communication is applied, or having the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied scrambled with a specific RNTI, 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 a PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as a NC-JT (Non-Coherent Joint Transmission) case.

[0630] 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.

[0631] 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.

[0632] For convenience in the following description, 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, can be described unified 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.

[0633] 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.

[0634] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. 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 embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and mobile communication technologies developed after 5G may be included here. Therefore, 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. The contents of the present disclosure can be applied to FDD, TDD, and XDD (or SBFD, full duplex) systems.

[0635] 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.

[0636] 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.

[0637] - MIB (Master Information Block)

[0638] - SIB (System Information Block) or SIB

[0639] - RRC (Radio Resource Control)

[0640] - MAC (Medium Access Control) CE (Control Element)

[0641] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using the following physical layer channels or signaling.

[0642] - PDCCH (Physical Downlink Control Channel)

[0643] - DCI (Downlink Control Information)

[0644] - UE-specific DCI

[0645] - Group common DCI

[0646] - Common DCI

[0647] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0648] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0649] - PUCCH (Physical Uplink Control Channel)

[0650] - UCI (Uplink Control Information)

[0651] 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.

[0652] 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.

[0653] Hereinafter, transmitting SRS antenna switching in the present disclosure may be understood as transmitting SRS based on the above-described SRS antenna switching and / or transmitting SRS for antenna switching (or SRS for antenna switching purposes). Hereinafter, SRS antenna switching transmitted by / from a terminal in the present disclosure may be understood as SRS transmitted based on SRS antenna switching and / or SRS for antenna switching transmitted by the terminal (or SRS for antenna switching purposes).

[0654] 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.

[0655] As explained above in antenna switching, since there is reciprocity between the uplink and downlink channels in a TDD system, if channel information for one of the two channels can be acquired, information for the other channel can also be estimated. Since the base station is configured with more transmit antennas than the terminal, in order to estimate the downlink channel between the base station and the terminal, the base station must transmit reference signals based on a larger number of reference signal (RS) ports / a larger number of RS ports to the terminal compared to estimating the uplink channel. For example, in order to orthogonally estimate the downlink channel between each transmit antenna port of the base station and all terminal antenna ports, a number of channel state information-reference signals (CSI-RS) is required equal to the number of transmit antennas of the base station. On the other hand, in order to estimate the downlink channel based on the uplink channel and reciprocity, the terminal can only transmit a number of sounding reference signals (SRS) equal to the number of receive antennas of the terminal to the base station.

[0656] Figure 8 is an example comparing a method of estimating a downlink channel based on CSI-RS and a method of estimating a downlink channel based on SRS and reciprocity. In Figure 8, it is assumed that a terminal (800) receives a downlink channel using two receive antennas and a base station (810) transmits a downlink channel using four transmit antennas.

[0657] Referring to FIG. 8, if the base station (810) transmits CSI-RS (821, 822, 823, 824) for each transmission antenna port to the terminal (800), the terminal can measure the downlink channel. Thereafter, the terminal (800) reports channel state information (hereinafter, CSI) of the downlink channel estimated by the received CSI-RS (821, 822, 823, 824) to the base station (810).

[0658] On the other hand, if the terminal (800) transmits SRS (831, 832) for each receiving antenna port to the base station (810), the base station can measure the uplink channel. If the base station measures the uplink channel based on the SRS and estimates the downlink channel through it, the base station has the advantage of being able to obtain downlink channel information without quantization error of the downlink channel due to CSI feedback, and considering the number of antenna ports of the base station and the terminal, the downlink channel can be estimated through a smaller number of SRS ports compared to the total number of CSI-RS ports.

[0659] Considering a high-performance base station with a large number of transmit antenna ports (for example, a base station with 32 transmit antenna ports), the advantages of SRS-based downlink channel estimation can be further enhanced. On the other hand, the transmit power of the SRS transmitted by the UE is very small compared to the transmit power of the CSI-RS transmitted by the base station. Therefore, if the distance between the base station and the UE is very large or sufficient uplink coverage is not secured, it may be difficult for the base station to successfully receive the SRS, or the uplink channel estimation error may be very large, making it difficult to estimate the downlink channel based on the reciprocity of the uplink channel. Despite these drawbacks, if sufficient uplink channel coverage between the base station and the UE can be secured, using a method for acquiring downlink channel information based on SRS can provide significant benefits from a system perspective, such as efficient RS resource utilization and error-free quantization of the downlink channel.

[0660] A terminal can support transmission via m antennas and reception via n antennas, as in 'mTnR'. Considering the complexity and cost of the transmitting antennas, the number of transmitting antennas m of the terminal can be less than or equal to the number of receiving antennas n.

[0661] If the number of transmit antennas m and the number of receive antennas n are the same, a separate antenna switching process for acquiring a downlink channel based on SRS, as described above, is not required. This can be understood as implementing an RF (radio frequency) chain for uplink transmission on each receive antenna.

[0662] On the other hand, if the number of receiving antennas n is greater than the number of transmitting antennas m, an antenna switching process may be required to transmit SRS through all n receiving antennas as described above. In the present disclosure, transmitting an RS (e.g., an SRS) through a receiving antenna may mean transmitting an RS (e.g., an SRS) by being connected to a receiving antenna (or antenna port). For specific details, refer to the description of antenna switching described above. For example, if a terminal is implemented with two transmitting antennas and four receiving antennas, the terminal needs to implement an SRS signal transmitted through a total of four antennas by switching the two transmitting antennas once each in order to transmit an SRS for downlink channel estimation for the four receiving antennas.

[0663] Considering the cost and complexity of the terminal, the number of transmit antennas may be smaller than the number of receive antennas of the terminal. That is, the receive modules, such as receive filters, are connected to all receive antenna parts of the terminal so that downlink signals can be received by n receive antennas, whereas transmit RF chain modules, such as transmit filters, low noise amplifiers (LNAs), and power amplifiers (PAs), may be connected to only some transmit antenna parts among all antennas so that uplink signals can be transmitted by only m transmit antennas. This may be an implementation that takes into account heat generation and cost of the terminal and interference between components. When the terminal supports mTnR and m is less than n, antenna switching can be performed to acquire a downlink channel based on SRS as described above.

[0664] Figure 9 illustrates an example of a case where a terminal performs SRS antenna switching and a base station acquires a downlink channel when the terminal supports 1T4R.

[0665] Referring to FIG. 9, a terminal can perform uplink transmission based on one transmit antenna port using one transmit module (which may be composed of, for example, LPAF (LNA, PA, and filter)) (900). If the terminal performs antenna switching for four receive antennas (901, 902, 903, 904), one transmit module (900) can transmit SRS by sequentially switching from the first antenna (901) to the fourth antenna (904) using a switch (905).

[0666] At this time, the SRS may be transmitted at a power lower than the power applied by the transmission module due to path loss according to the form factor of the terminal and the arrangement of the receiving antenna. This can be defined as insertion loss (IL). In addition, the terminal may intentionally lower the target power value to prevent interference or interference depending on the operation of other components of the terminal (e.g., a camera, Bluetooth, Wi-Fi, or other RF components, etc.) as well as reasons such as terminal shape and path loss. That is, when performing SRS antenna switching, an imbalance may occur in the SRS transmission power (911, 912, 913, 914) transmitted by each antenna due to not only insertion loss but also interactions between other components of the terminal.

[0667] As shown in the example in Fig. 9, the size of the SRS transmission power (912 to 914) transmitted through the second to fourth antennas may be relatively smaller than the SRS transmission power (911) transmitted through the first antenna. This can be defined as insertion loss imbalance (IL imbalance). That is, a problem may occur in which the terminal cannot transmit the SRS transmitted through each receiving antenna with uniform transmission power due to the interaction between the transmission module and antenna arrangement of the terminal and other elements.

[0668] Fig. 10 is a diagram illustrating an example of a terminal structure supporting four receiving antennas. Specifically, Fig. 10 is an example of a terminal supporting four receiving antennas (1001 to 1004).

[0669] Referring to FIG. 10, unlike the transmitting module, the receiving module (DRX-M, diversity Rx module) (1011 to 1014) for diversity support is cheaper than the transmitting module and can be implemented with a simple structure, so it can be placed and operated on all receiving antennas. Accordingly, there may not be a large difference in the insertion loss between each receiving antenna (1001 to 1004) and the receiving module (1011 to 1014), and therefore, unlike the transmitting case described above in FIG. 9, the imbalance between the downlink channel or downlink reference signal, such as CSI-RS, received by each antenna may be very small or non-existent.

[0670] As shown in Figures 9 and 10, a difference may occur between the downlink channel estimated based on the SRS transmitted by the terminal and the downlink channel received by the terminal, depending on whether IL imbalance occurs. That is, the base station ideally expects the downlink channel received by the terminal and the downlink channel acquired through SRS antenna switching to be the same, but the occurrence of IL imbalance may cause an estimation error between the actual downlink channel received by the terminal and the downlink channel estimated by the base station through SRS antenna switching. If the accuracy of the downlink channel estimated by the base station through SRS antenna switching can be improved, the base station can perform accurate precoding on the downlink channel transmitted to the terminal, and the beamforming gain can be maximized through accurate precoding, thereby increasing the downlink throughput.

[0671] This disclosure specifically describes a method in which a terminal reports additional information to a base station to correct errors in the downlink channel estimated by the base station through SRS antenna switching, and the base station improves the accuracy of the downlink channel estimated through SRS antenna switching based on the additional information reported. The following embodiments are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0672] <First embodiment: Method for configuring multiple precoded (multiple precoded) CSI-RSs for CSI comparison>

[0673] In the first embodiment, a method is specifically described in which a base station transmits multiple precoded CSI-RSs for comparison by a terminal to calculate additional information for correcting an error in a downlink channel estimated by the base station through SRS antenna switching.

[0674] If the base station and the terminal select a precoder for downlink channel transmission based on the same precoder set (in the case of the terminal, if the precoder for CSI reporting is selected), the precoder determined by the base station based on the downlink channel estimated through SRS antenna switching and the precoder determined by the terminal based on the received CSI-RS may have different values ​​selected depending on the channel estimation error caused by the occurrence of the IL imbalance described above. If the difference between the precoders selected based on the downlink channel estimation error can be compensated for in this way, the base station can calculate a more accurate precoder by using the downlink channel estimated through SRS antenna switching and the information that can compensate the precoder.

[0675] Meanwhile, the actual downlink channel can be received by the terminal, and the terminal may not be able to report the downlink channel received by the base station to the base station without quantization error due to CSI feedback overhead, etc. Therefore, even if the terminal selects a precoder based on the received downlink channel and performs CSI reporting, the base station can only identify the information of the precoder determined based on SRS antenna switching and the precoder reported by the terminal, and there is a problem that the effective channel through which the actual precoded information is transmitted and received by the terminal cannot be identified.

[0676] Uplink channel with error due to IL imbalance according to mathematical equation 2 below Explains.

[0677] [Equation 2]

[0678]

[0679] Here, n represents the number of receiving antennas of the terminal. refers to the uplink channel received by the base station through SRS antenna switching transmitted through the xth receiving antenna of the terminal, and is a vector The size of [the number of transmitting and receiving antennas of the base station, ] can be defined as a base station with the same number of With a dog transmitting antenna Assume that it is implemented with a dog receiving antenna. is a diagonal matrix representing the IL imbalance caused by insertion loss and other components of the terminal. Each element refers to the size of the IL imbalance that occurs when the SRS is transmitted at time t through the xth receiving antenna of the terminal. Finally, the uplink channel received by the base station refers to an uplink channel that includes IL imbalance and causes estimation errors, and the matrix The size of [the number of transmitting and receiving antennas of the base station, The number of receiving antennas of the terminal can be defined as [n]. The base station receives the uplink channel Downlink channel based on according to channel reciprocity It can be estimated as follows, and based on this, a precoder that can maximize the throughput of downlink data (or meet a specific target performance depending on the implementation of the base station) can be decided.

[0680] Meanwhile, the terminal can receive CSI-RS from the base station, calculate CSI, and report the CSI to the base station. The terminal can transmit the downlink channel from the received CSI-RS. can be estimated. Here, refers to the number of transmitting and receiving antennas of the base station, refers to the downlink channel received by the terminal as CSI-RS transmitted through the yth transmit / receive antenna of the base station, and [the number of receiving antennas of the terminal, ] can be defined as the downlink channel that the terminal ultimately receives. The size of [the number of receiving antennas of the terminal, Number of transmitting and receiving antennas of the base station, ] can be defined. The terminal receives the CSI-RS and estimates the downlink channel. The terminal can determine the PMI for the CSI. The terminal can multiplex the CSI including the determined PMI onto the PUSCH and report it to the base station. The base station can perform precoder operation through the PMI included in the CSI reported by the terminal. can be determined. Here, the base station calculates And the terminal calculated may be precoders selected with the same type of precoding scheme (for example, they may all be precoders selected with eigen decomposition-based precoding methods). Alternatively, they may be precoders selected with different types of precoding schemes depending on the implementation between each base station and terminal.

[0681] The base station can choose the following methods to support downlink channel transmission:

[0682] - Whether to acquire a downlink channel based on SRS antenna switching and transmit the downlink channel, or

[0683] - Obtain downlink channel information based on CSI-RS transmission and terminal CSI report to determine whether to transmit the downlink channel or not.

[0684] - By using both SRS antenna switching and CSI-RS, the accuracy of the SRS antenna switching-based downlink channel estimation method can be improved to determine whether to transmit the downlink channel.

[0685] The base station may decide one of the above methods after receiving the SRS for SRS antenna switching and the CSI-RS-based CSI report. Alternatively, the base station may decide one of the above methods after receiving only the SRS for SRS antenna switching or only the CSI-RS-based CSI report (after receiving either the SRS for SRS antenna switching or the CSI-RS-based CSI report).

[0686] If the base station improves the accuracy of the downlink channel estimation method based on SRS antenna switching by utilizing both SRS antenna switching and CSI-RS, the base station can transmit multiple precoded CSI-RSs to the terminal to improve the estimation accuracy of the downlink channel, and the terminal can use the received multiple precoded CSI-RSs to feed back correction information for correcting the estimation error of the downlink channel estimated based on SRS antenna switching (hereinafter referred to as “correction information”) to the base station. This is because the base station cannot determine the effective channel received by the terminal through each precoder, so the terminal measures the effective channel and reports information for correcting the difference between the effective channels to the base station, thereby allowing the base station to determine the difference between the effective channels and correct the downlink channel estimated based on SRS antenna switching, thereby improving the downlink throughput performance. In this way, a CSI reporting configuration can be defined for the terminal to report the correction information to the base station by utilizing multiple precoded CSI-RSs. A specific method for configuring CSI reporting is presented in the third embodiment.

[0687] The base station can transmit multiple precoded CSI-RSs to the terminal to be used for calculating correction information using the following method.

[0688] - The base station determines the precoder based on the SRS antenna switching transmitted by the terminal for the first precoded CSI-RS. can be determined by referring to. Here, the meaning of reference is the precoder determined by the base station. This means that it can be applied to transmit CSI-RS as is without any additional modification or depending on the implementation of the base station. This may mean applying the modification to transmit the CSI-RS. The first precoded CSI-RS may be composed of multiple CSI ports.

[0689] - The base station determines the second precoded CSI-RS based on the CSI reported by the terminal. can be determined by referring to. Similarly, the meaning of the reference is determined by the precoder based on the CSI reported by the terminal. This means that it can be applied to transmit CSI-RS as is without any additional modification or depending on the implementation of the base station. This may mean applying the modified CSI-RS to transmit the second precoded CSI-RS. The second precoded CSI-RS may be composed of multiple CSI ports.

[0690] - When the base station transmits the first precoded CSI-RS and the second precoded CSI-RS to the terminal, certain constraints may be considered for transmitting the two precoded CSI-RSs. For example, the two precoded CSI-RS resources may have to be configured with the same number of CSI ports. For another example, the two precoded CSI-RS resources may have to be transmitted on physical resource elements that do not overlap in the time and / or frequency domain. Alternatively, the two precoded CSI-RS resources may have to be transmitted on physical resource elements that overlap in the time and / or frequency domain. If the two precoded CSI-RSs are transmitted periodic or semi-persistently, the periods of the two precoded CSI-RSs may have to be the same. Alternatively, the periods of the two precoded CSI-RSs may have some relationship (e.g., the period of the first precoded CSI-RS may be k times the period of the second precoded CSI-RS, etc.).

[0691] In this way, the base station can transmit multiple precoded CSI-RSs to the terminal, and the terminal can determine information for correcting downlink channel estimation errors based on the multiple precoded CSI-RSs received, as in the second embodiment.

[0692] <Example 2: Method for Determining Information for Downlink Channel Estimation Error Correction by Comparing Multiple Precoded CSI-RSs>

[0693] In the second embodiment, a method for comparing multiple precoded CSI-RSs received by a terminal to determine a difference between two valid channels and, based on this, calculating / generating / acquiring information for correcting an estimation error in downlink channel estimation using SRS antenna switching is specifically described.

[0694] In the first embodiment described above, the base station can transmit multiple precoded CSI-RSs to the terminal to instruct the terminal to determine correction information. The terminal receives multiple precoded CSI-RSs transmitted by the base station according to the first embodiment. When the base station transmits the first and second precoded CSI-RSs, it is assumed that the base station applies precoding without modifying the CSI-RSs when transmitting the CSI-RSs. The terminal determines the effective channel through the first precoded CSI-RS. can be estimated, and the effective channel can be estimated through the second precoded CSI-RS. can be estimated. This is just an example for convenience of explanation, and the base station transmits the first precoded CSI-RS and the second precoded CSI-RS. and CSI-RS can also be transmitted by applying a precoder other than the two effective channels estimated by the terminal. and This causes a difference in the two effective channels because they are transmitted to the terminal through different precoders.

[0695] Finally, the base station can be expected to estimate a downlink channel with a small estimation error even without receiving CSI-RS-based CSI feedback by performing correction at the base station end based on SRS antenna switching and correction information, and to determine a downlink precoder that can increase downlink throughput based on this. Therefore, the terminal can estimate the downlink channel with a small estimation error through precoded CSI based on SRS antenna switching. Any information Corrected with (correction information) If we can derive the same or similar valid channel, this information By reporting to the base station, the base station obtains the channel using SRS antenna switching (only). By compensating, a compensated downlink channel with a small estimation error can be obtained even if CSI-RS is transmitted and CSI is not reported.

[0696] so Correction information to derive the same or similar effective channel Depending on the implementation of the terminal, it can be determined in some way. For example, the terminal can use the following methods.

[0697] - [Method 1]: The terminal can minimize the difference between each effective channel. You can report to the base station by selecting . To minimize the difference The method of selecting is to minimize the mean squared error (MSE) as in the following mathematical formula 3. The terminal can select and report to the base station. The terminal satisfies mathematical expression 3. can be reported to the base station.

[0698] [Equation 3]

[0699]

[0700] - [Method 2]: The terminal can maximize the correlation between each effective channel. You can report to the base station by selecting . To maximize correlation, The following mathematical expression 4 can be considered as a method for selecting a terminal satisfying mathematical expression 4. can be reported to the base station.

[0701] [Equation 4]

[0702]

[0703] Next, the terminal is based on the method according to the implementation of the above-described [Method 1] and [Method 2] or any terminal not described above. Candidates for determining can be determined as follows depending on the implementation of the terminal.

[0704] - [Candidate 1] Precoder matrix candidates based on DFT (discrete Fourier transform) can be considered. Candidate matrices can be generated based on DFT vectors generated in various phases.

[0705] - [Candidate 2] Non-DFT-based precoder matrix candidates can be considered. The candidate matrices can be generated based on computer-generated vectors, and each vector may maintain the orthonomal (orthogonal) property with respect to each other.

[0706] - [Candidate 3] Eigen decomposition-based precoder matrix candidates can be considered. The candidate matrices can be constructed with an eigen basis selected from the eigenspace generated for various randomly generated channels. Similarly, vectors within the matrix can maintain the orthonomal (orthogonal) property.

[0707] - [Candidate 4] Precoder matrix candidates for port selection can be considered. Candidate matrices can be generated based on vectors in which some elements have non-zero values ​​and the remaining elements are zero.

[0708] In addition to [Candidate 1] to [Candidate 4], any matrix candidates that can minimize the difference between two valid channels or maximize the correlation according to the above-described [Method 1] or [Method 2] or other methods. or Candidates for determining can be configured. According to one embodiment of the present disclosure, the base station and the terminal can operate based on a common codebook. That is, the base station and the terminal can support a framework for reporting correction information based on any agreed-upon codebook, and the base station can set upper layer parameters to the terminal based on this, and the terminal can report a capability report that it can support the corresponding capability to the base station based on this, and also report the correction information calculated by the terminal to the base station.

[0709] <Third Embodiment: Method for Reporting Calculated Channel Estimation Error Correction Information>

[0710] In the third embodiment, a method for reporting correction information calculated by a terminal according to the first and second embodiments to a base station and a method for setting upper layer parameters for the base station to receive the report are specifically described.

[0711] Before explaining a specific example, the following signaling between a base station and a terminal may be assumed in the third embodiment. The base station may receive a terminal capability report from the terminal indicating that it can support enhanced SRS antenna switching-based downlink channel estimation using compensation information. The base station may set upper layer parameters for supporting the enhanced SRS antenna switching-based downlink channel estimation method using compensation information to the terminal based on the terminal capability report reported by the terminal. At this time, the base station may additionally set an RRC parameter 'enableCompensationSRS' (or an RRC parameter of any name indicating that the enhanced SRS antenna switching-based downlink channel estimation method using compensation information is supported) to the terminal. In the following specific examples, it is assumed that the base station sets an RRC parameter 'enableCompensationSRS', etc. to the terminal. The names of RRC IEs (information elements) in the present disclosure are examples, and the present disclosure is not limited to specific names.

[0712] In order for the base station to transmit and the terminal to receive the multiple precoded CSI-RSs described in the first embodiment, the base station can include configurations for all CSI-RS resources in the configuration for the CSI resource. For example, the base station can configure multiple NZP-CSI-RS-ResourceSets in the upper layer parameter CSI-ResourceConfig for the CSI resource to the terminal. If multiple NZP-CSI-RS-ResourceSets are configured, each NZP-CSI-RS-ResourceSet can be used to configure each precoded CSI-RS. Alternatively, the base station can configure one NZP-CSI-RS-ResourceSet in the upper layer parameter CSI-ResourceConfig for the CSI resource to the terminal and configure multiple NZP-CSI-RS-Resources in the NZP-CSI-RS-ReosurceSets. If multiple NZP-CSI-RS-Resources are configured within a single NZP-CSI-RS-ResourceSet, each NZP-CSI-RS-Resource can be used to configure each precoded CSI-RS.

[0713] When multiple precoded CSI-RS configurations are included in a single CSI-ResourceConfig, the multiple precoded CSI-RSs can be configured to be received in association with a single CSI reporting configuration. That is, a CSI-ResourceConfig in which multiple precoded CSI-RSs are configured can be configured to be associated with a certain CSI-ReportConfig. If CSI reporting for a certain CSI-ReportConfig is scheduled / configured, the UE can receive multiple precoded CSI-RSs according to the CSI-ResourceConfig associated with the corresponding CSI-ReportConfig, calculate correction information for the same, and report the same to the base station. Here, conventional values ​​may be used as 'reportQuantity' in the CSI-ReportConfig, or a quantity for reporting correction information may be defined and instructed based on this. For example, 'reportQuantity' in the CSI-ReportConfig may be set to a value such as 'PMI_forcompen' or 'SRS_compen'. Or it may be set to a value of some name to instruct the terminal to report correction information.

[0714] The reporting method for the terminal to report correction information can be triggered and performed aperiodically through DCI according to the settings of CSI-ResportConfig. Alternatively, the reporting method for the terminal to report correction information can be performed semi-persistently through upper layer parameters and DCI for activation according to the settings of CSI-ResportConfig. Alternatively, the reporting method for the terminal to report correction information can be configured / performed periodically through upper layer parameters according to the settings of CSI-ReportConfig.

[0715] Additionally, as described in the first embodiment, the index of the SRS resource set for SRS antenna switching purposes used to determine the precoded CSI-RS may be set in CSI-ReportConfig, and the SRS resource set associated with reporting the correction information may be set as a higher layer parameter.

[0716] Alternatively, in order for the base station to transmit and the terminal to receive multiple precoded CSI-RSs as described in the first embodiment, the base station may configure CSI resources for each CSI-RS resource. The base station may configure multiple upper layer parameters CSI-ResourceConfig for CSI resources to the terminal for each precoded CSI-RS. That is, the base station may configure two CSI-ResourceConfigs for two precoded CSI-RSs to the terminal, respectively. The base station may configure one NZP-CSI-RS-ResourceSet for each CSI-ResourceConfig, and configure (at least) one NZP-CSI-RS-Resource within one NZP-CSI-RS-ResourceSet for the corresponding precoded CSI-RS.

[0717] Multiple CSI-ResourceConfigs configured for each precoded CSI-RS can be associated with a single CSI-ReportConfig. That is, a single CSI-ReportConfig can be associated with multiple CSI-ResourceConfigs, and each CSI-ResourceConfig can be a resource configuration for each precoded CSI-RS.

[0718] If CSI reporting for a certain CSI-ReportConfig is scheduled / configured, the terminal can receive multiple precoded CSI-RSs according to multiple CSI-ResourceConfigs associated with the corresponding CSI-ReportConfig, calculate compensation information for the same, and report the same to the base station. Here, the 'reportQuantity' in the CSI-ReportConfig can use conventional values ​​or define and instruct the quantity for reporting the compensation information. For example, the 'reportQuantity' in the CSI-ReportConfig can be set to a value such as 'PMI_forcompen' or 'SRS_compen'. Alternatively, it can be set to a value with a certain name for instructing the terminal to report the compensation information.

[0719] The reporting method for the terminal to report correction information can be triggered and performed aperiodically through DCI according to the settings of CSI-ReportConfig. Alternatively, the reporting method for the terminal to report correction information can be performed semi-persistently through upper layer parameters and DCI for activation according to the settings of CSI-ReportConfig. Alternatively, the reporting method for the terminal to report correction information can be configured / performed periodically through upper layer parameters according to the settings of CSI-ReportConfig.

[0720] Additionally, as described in the first embodiment, the index of the SRS resource set for SRS antenna switching purposes used to determine the precoded CSI-RS may be set in CSI-ReportConfig, and the SRS resource set associated with reporting the correction information may be set as a higher layer parameter.

[0721] Alternatively, resource configuration and correction information reporting settings unrelated to CSI resource configuration and CSI reporting settings may be considered. New configurations for precoded CSI-RS, a reporting format for reporting the same, and an uplink channel indication may be added. The reporting method for reporting correction information may be triggered aperiodically via DCI depending on the reporting configuration. Alternatively, the reporting method for reporting correction information may be performed semi-persistently via higher layer parameters and DCI for activation depending on the reporting configuration. Alternatively, the reporting method for reporting correction information may be performed periodically via higher layer parameters depending on the reporting configuration.

[0722] Additionally, as described in the first embodiment, the index of the SRS resource set for SRS antenna switching purposes used to determine the precoded CSI-RS may be included in the setting for reporting, and the SRS resource set associated with reporting the correction information may be set as a higher layer parameter.

[0723] <Fourth Embodiment: Method for Supporting Downlink Channel Transmission Based on Estimation Error Correction Information>

[0724] In the fourth embodiment, a method is described in which a base station estimates a downlink channel based on SRS antenna switching in an improved manner using correction information received from a terminal according to the first to third embodiments and supports downlink channel transmission to the terminal.

[0725] The base station can receive correction information transmitted by the terminal according to the operations of the base station and the terminal described in the first to third embodiments. Based on this, the base station can obtain correction information to correct the estimation error of the downlink channel estimated by SRS antenna switching. The base station can apply the received correction information to the downlink channel estimated by SRS antenna switching according to the base station implementation method.

[0726] After receiving a report of correction information from a terminal, the base station can estimate the downlink channel only using SRS antenna switching and the reported correction information without receiving additional correction information reports for a certain period of time. In other words, the base station can estimate the downlink channel between the terminal and the base station by scheduling / configuring only SRS antenna switching without transmitting CSI-RS to estimate the downlink channel for a certain period of time.

[0727] The period of time during which the base station does not transmit CSI-RS for downlink channel estimation may be determined by the implementation of the base station or may be a time window predefined by the base station and the terminal. If the base station and the terminal define a period of time during which the base station and the terminal do not transmit CSI-RS for downlink channel estimation in advance, the base station may set information about the period of time to the terminal as a higher layer parameter. If the base station determines the period of time according to its implementation, the base station may determine the period of time comprehensively considering the downlink channel estimated by the SRS antenna switching transmitted by the terminal and the ACK (acknowledgement), NACK (negative ACK) and retransmission rate for the downlink channel transmitted to the terminal based on this.

[0728] Figure 11 is a diagram illustrating an exemplary operational flowchart of a base station and a terminal according to an embodiment. Various modifications may be made to the method illustrated in Figure 11. 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.

[0729] Referring to FIG. 11, a base station (1100) can schedule / configure SRS antenna switching for a terminal (1150). At this time, the SRS antenna switching can be scheduled / configured based on DCI or higher layer parameters.

[0730] In operation 1101, the terminal can transmit scheduled / configured SRS antenna switching to the base station. That is, the terminal can transmit an SRS for scheduled / configured SRS antenna switching (SRS according to SRS antenna switching) to the base station.

[0731] In operation 1102, the base station can estimate the uplink channel through the SRS according to the received SRS antenna switching and estimate the downlink channel through the reciprocity.

[0732] In operation 1103, the base station can transmit a CSI-RS to the terminal. At this time, the CSI-RS transmitted by the base station can be scheduled / configured based on DCI or higher layer parameters.

[0733] In operation 1104, the terminal can prepare a CSI report based on the received CSI-RS.

[0734] In operation 1105, the terminal can transmit the prepared CSI to the base station, and the CSI can be multiplexed and transmitted on PUSCH or PUCCH according to the CSI reporting configuration. At this time, the CSI reporting can be scheduled / configured based on DCI or higher layer parameters.

[0735] In operation 1106, the base station can select a downlink channel estimation method to support based on the CSI report received from the terminal and the downlink channel information estimated by SRS antenna switching.

[0736] If the base station does not support enhanced SRS antenna switching based downlink channel estimation using correction information, the base station may support the terminal using the SRS antenna switching or CSI-RS based downlink channel estimation method without performing a series of processes for determining and reporting separate correction information during a specific time interval (coherent time, coherence time, 1116). Alternatively, the base station may not support enhanced SRS antenna switching based downlink channel estimation using correction information for a longer time interval, such as upper layer parameter reset or cell re-search, other than the specific time interval (1116).

[0737] If the base station supports enhanced SRS antenna switching-based downlink channel estimation using correction information, the base station may transmit multiple precoded CSI-RSs (Precoded CSI-RS1 and Precoded CSI-RS2) to the terminal in operations 1107 and 1108. Alternatively, the precoded CSI-RSs may be referred to as beamformed CSI-RSs. For more specific details, refer to the description of the first embodiment described above.

[0738] In operation 1109, the terminal may calculate compensation information (compen.info.) based on the received multiple precoded CSI-RSs and prepare a report. For more specific details, refer to the description of the second embodiment described above.

[0739] In operation 1110, the terminal may report correction information to the base station according to the upper layer configuration for reporting correction information. Similar to CSI, the correction information may be multiplexed onto the PUSCH or PUCCH and reported to the base station according to the upper layer configuration. For more specific details, please refer to the description of the third embodiment described above.

[0740] In operation 1111, the base station can perform improved downlink channel estimation by applying the received correction information to the downlink channel estimated by SRS antenna switching.

[0741] Afterwards (if there is downlink data to transmit), in operation 1112, the base station can determine the precoder of the estimated downlink channel through enhanced downlink channel estimation and transmit the downlink channel to the terminal.

[0742] Thereafter, the base station performs enhanced downlink channel estimation through a process of switching the SRS antenna transmitted by the terminal (1113) and applying the received correction information (1114) without performing a series of operations (1103 to 1110) for reporting correction information for a certain period of time (coherence time, 1116). In operation 1115, the base station can transmit downlink data to the terminal based on the downlink channel estimated based thereon.

[0743] After a certain time interval (1116) has elapsed from a certain point in time (the SRS antenna switching transmission point (1101) which is the point in time of reporting correction information in FIG. 11, but the point in time (1110) at which correction information is reported may be the point in time or any other point in time), the base station schedules / configures SRS antenna switching to the terminal in order to perform a series of operations (1103 to 1110) for reporting correction information in operation 1117, and the terminal may perform SRS antenna switching.

[0744] In subsequent operation 1118, the base station may transmit the CSI-RS to the terminal to transmit multiple precoded CSI-RSs. Subsequent operations to support enhanced downlink channel estimation, such as CSI reporting (1105), multiple precoded CSI-RS transmission / reception (1107, 1108), and correction information reporting (1110), may be repeatedly performed at regular intervals or the corresponding operations may be triggered based on DCI.

[0745] For more specific details on the operation of the terminal / base station according to one embodiment of the present disclosure described above, reference may be made to the description of one embodiment of the present disclosure described above.

[0746] FIG. 12 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0747] Referring to FIG. 12, the terminal may include a transceiver, which refers to a terminal receiving unit (12-00) and a terminal transmitting unit (12-10), a memory (not shown), and a terminal processing unit (12-05, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (12-00, 12-10), the memory, and the terminal processing unit (12-05) 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.

[0748] 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.

[0749] 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.

[0750] 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.

[0751] 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.

[0752] FIG. 13 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0753] Referring to FIG. 13, the base station may include a transceiver, which refers to a base station receiver (13-00) and a base station transmitter (13-10), a memory (not shown), and a base station processing unit (13-05, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver units (13-00, 13-10), the memory, and the base station processing unit (13-05) 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.

[0754] 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.

[0755] 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.

[0756] 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.

[0757] 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.

[0758] 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.

[0759] 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.

[0760] 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.

[0761] 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.

[0762] In the specific embodiments of the present disclosure described above, components included in each embodiment 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.

[0763] 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.

[0764] 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.

[0765] 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.

[0766] 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.

[0767] 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 terminal in a communication system, A step of receiving, through upper layer signaling, a sounding reference signal (SRS) related configuration including a usage parameter indicating antenna switching; A step of transmitting SRS corresponding to the above antenna switching; A step of receiving a CSI-RS (channel state information reference signal); A step of transmitting a CSI report based on the above CSI-RS; A step of receiving a plurality of precoded CSI-RSs, wherein the plurality of precoded CSI-RSs include a first precoded CSI-RS corresponding to the SRS and a second precoded CSI-RS corresponding to the CSI report; and A method comprising the step of transmitting compensation information based on the plurality of precoded CSI-RSs, wherein the compensation information is for compensating for SRS-based downlink channel estimation corresponding to the antenna switching.

2. In paragraph 1, The above correction information is for correction of SRS-based downlink channel estimation corresponding to the antenna switching during a certain time period during which SRS-based downlink channel estimation corresponding to the antenna switching is applied. The above-mentioned predetermined time interval is predefined, set through the upper layer signaling, or determined based on information related to a downlink channel and a hybrid automatic repeat request (HARQ-ACK) corresponding to the downlink channel and SRS-based downlink channel estimation corresponding to the antenna switching. A method wherein a downlink channel received within the above-mentioned predetermined time period is based on precoding related to SRS-based downlink channel estimation corresponding to the antenna switching corrected according to the above-mentioned correction information.

3. In paragraph 1, The above plurality of precoded CSI-RSs are received based on a plurality of CSI-RS resource configurations, and the plurality of CSI-RS resource configurations are associated with a CSI reporting configuration, The above multiple CSI-RS resource settings and the above CSI reporting settings are received through the upper layer signaling, A method wherein the above CSI reporting settings include a reportQuantity parameter that instructs reporting of a CSI related quantity corresponding to the correction information.

4. In paragraph 1, The steps for transmitting the above correction information are: A step of determining a first precoder based on the first precoded CSI-RS; A step of determining a second precoder based on the second precoded CSI-RS; A step of determining a first valid channel estimate based on a channel estimate corresponding to the CSI-RS and the first precoder; A step of determining a second valid channel estimate based on a channel estimate corresponding to the CSI-RS and the second precoder; A step of determining a correction value corresponding to a precoder based on the first effective channel estimate and the second effective channel estimate, wherein the correction value is a value that minimizes a difference between the first effective channel estimate and the second effective channel estimate, or a value that maximizes a correlation between the first effective channel estimate and the second effective channel estimate; and A method comprising the step of transmitting correction information including the correction value.

5. In paragraph 1, A step of transmitting terminal capability information related to whether or not to support SRS-based downlink channel estimation corresponding to the antenna switching based on the above correction information; and A method further comprising the step of receiving information indicating activation of SRS-based downlink channel estimation corresponding to the antenna switching based on the correction information through the upper layer signaling.

6. At the terminal of the communication system, Transmitter and receiver; and A processor coupled to the transceiver, the processor comprising: Receive SRS (sounding reference signal) related settings including usage parameters indicating antenna switching via upper layer signaling; Transmit SRS corresponding to the above antenna switching; Receive CSI-RS (channel state information reference signal); Transmit CSI report based on the above CSI-RS; Receiving a plurality of precoded CSI-RSs, the plurality of precoded CSI-RSs including a first precoded CSI-RS corresponding to the SRS and a second precoded CSI-RS corresponding to the CSI report; and A terminal configured to transmit compensation information based on the plurality of precoded CSI-RSs, wherein the compensation information is for compensation for SRS-based downlink channel estimation corresponding to the antenna switching.

7. In paragraph 6, The above correction information is for correction of SRS-based downlink channel estimation corresponding to the antenna switching during a certain time period during which SRS-based downlink channel estimation corresponding to the antenna switching is applied. The above-mentioned predetermined time interval is predefined, set through the upper layer signaling, or determined based on information related to a downlink channel and a hybrid automatic repeat request (HARQ-ACK) corresponding to the downlink channel and SRS-based downlink channel estimation corresponding to the antenna switching. A terminal based on precoding related to SRS-based downlink channel estimation corresponding to the antenna switching corrected according to the correction information, wherein the downlink channel received within the above-mentioned predetermined time period is corrected.

8. In paragraph 6, The above plurality of precoded CSI-RSs are received based on a plurality of CSI-RS resource configurations, and the plurality of CSI-RS resource configurations are associated with a CSI reporting configuration, The above multiple CSI-RS resource settings and the above CSI reporting settings are received through the upper layer signaling, The above CSI reporting setting is a terminal including a reportQuantity parameter that instructs reporting of a CSI related quantity corresponding to the above correction information.

9. In paragraph 6, In transmitting the above correction information, the processor: Determine a first precoder based on the first precoded CSI-RS; Determine a second precoder based on the second precoded CSI-RS; Determining a first valid channel estimate based on a channel estimate corresponding to the CSI-RS and the first precoder; Determine a second valid channel estimate based on the channel estimate corresponding to the CSI-RS and the second precoder; Determine a correction value corresponding to the precoder based on the first effective channel estimate and the second effective channel estimate, the correction value being a value that minimizes a difference between the first effective channel estimate and the second effective channel estimate or a value that maximizes a correlation between the first effective channel estimate and the second effective channel estimate; and A terminal configured to transmit correction information including the above correction value.

10. In paragraph 6, the processor: Transmitting terminal capability information related to whether or not to support SRS-based downlink channel estimation corresponding to the antenna switching based on the above correction information; and A terminal configured to receive information indicating activation of SRS-based downlink channel estimation corresponding to the antenna switching based on the correction information through the upper layer signaling.

11. In a method performed by a base station in a communication system, A step of transmitting SRS (sounding reference signal) related settings including a usage parameter indicating antenna switching through upper layer signaling; A step of receiving an SRS corresponding to the above antenna switching; A step of transmitting CSI-RS (channel state information reference signal); A step of receiving a CSI report corresponding to the above CSI-RS; A step of transmitting a plurality of precoded CSI-RSs, wherein the plurality of precoded CSI-RSs include a first precoded CSI-RS corresponding to the SRS and a second precoded CSI-RS corresponding to the CSI report; and A method comprising: receiving compensation information based on the plurality of precoded CSI-RSs, wherein the compensation information is for compensating for SRS-based downlink channel estimation corresponding to the antenna switching.

12. In paragraph 11, The above correction information is for correction of SRS-based downlink channel estimation corresponding to the antenna switching during a certain time period during which SRS-based downlink channel estimation corresponding to the antenna switching is applied. The above-mentioned predetermined time interval is predefined, set through the upper layer signaling, or determined based on information related to a downlink channel and a hybrid automatic repeat request (HARQ-ACK) corresponding to the downlink channel and SRS-based downlink channel estimation corresponding to the antenna switching. A method wherein a downlink channel transmitted within the above-mentioned predetermined time interval is based on precoding related to SRS-based downlink channel estimation corresponding to the antenna switching corrected according to the above-mentioned correction information.

13. In paragraph 11, The above plurality of precoded CSI-RSs are based on a plurality of CSI-RS resource configurations, and the plurality of CSI-RS resource configurations are associated with a CSI reporting configuration, The above multiple CSI-RS resource settings and the above CSI reporting settings are transmitted through the upper layer signaling, A method wherein the above CSI reporting settings include a reportQuantity parameter that instructs reporting of a CSI related quantity corresponding to the correction information.

14. In the base station of the communication system, Transmitter and receiver; and A processor coupled to the transceiver, the processor comprising: Transmitting SRS (sounding reference signal) related settings including usage parameters indicating antenna switching via upper layer signaling; Receive SRS corresponding to the above antenna switching; Transmit CSI-RS (channel state information reference signal); Receive a CSI report corresponding to the above CSI-RS; Transmitting a plurality of precoded CSI-RSs, the plurality of precoded CSI-RSs including a first precoded CSI-RS corresponding to the SRS and a second precoded CSI-RS corresponding to the CSI report; and A base station configured to receive compensation information based on the plurality of precoded CSI-RSs, wherein the compensation information is for compensating for SRS-based downlink channel estimation corresponding to the antenna switching.

15. In paragraph 14, The above correction information is for correction of SRS-based downlink channel estimation corresponding to the antenna switching during a certain time period during which SRS-based downlink channel estimation corresponding to the antenna switching is applied. The above-mentioned predetermined time interval is predefined, set through the upper layer signaling, or determined based on information related to a downlink channel and a hybrid automatic repeat request (HARQ-ACK) corresponding to the downlink channel and SRS-based downlink channel estimation corresponding to the antenna switching. A base station, wherein the downlink channel transmitted within the above-mentioned predetermined time period is based on precoding related to SRS-based downlink channel estimation corresponding to the antenna switching corrected according to the above-mentioned correction information.

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