Method and apparatus for sounding reference signal transmission in a wireless communication system

Abstract

The disclosure relates to a fifth generation (5G) or sixth generation (6G) communication system for supporting a higher data transmission rate. The disclosure relates to operations of a user equipment (UE) and a base station in a wireless communication system. A method performed by a UE in a communication system is provided. The method includes transmitting, to a base station, capability information associated with a synchronization sounding reference signal (SRS) carrier switching, receiving, from the base station, a downlink control information (DCI) format, wherein the DCI format schedules SRSs in component carriers (CCs) for the SRS carrier switching, wherein the SRSs overlap in time based on the capability information indicating support for the synchronization SRS carrier switching, and transmitting, to the base station, at least one of the scheduled SRSs for the SRS carrier switching.

Description

Technical Field

[0001] This disclosure relates to the operation of user equipment (UE) and base stations in a wireless communication system. More specifically, this disclosure relates to a method for transmitting a probe reference signal in a wireless communication system, and an apparatus capable of performing the method. Background Technology

[0002] Fifth-generation (5G) mobile communication technology defines wide bandwidth, enabling high transmission rates and new services. It can be implemented not only in the "sub-6 GHz" band, such as 3.5 GHz, but also in the "above 6 GHz" band, known as millimeter wave (mmWave), including 28 GHz and 39 GHz. Furthermore, sixth-generation (6G) mobile communication technology (called "super 5G systems") is being considered in terahertz bands (e.g., the 95 GHz to 3 THz band) to achieve transmission rates fifty times faster than 5G and ultra-low latency one-tenth that of 5G.

[0003] In the early stages of 5G mobile communication technology development, in order to support and meet the performance requirements of services related to enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC), standardization has been carried out on the following technologies: beamforming and massive multiple-input multiple-output (MIMO) for reducing radio wave path loss and increasing radio wave transmission distance in millimeter waves; support parameter sets for dynamic operation (e.g., operating multiple subcarrier spacings) for efficient utilization of millimeter wave resources and time slot formats; initial access technologies for supporting multi-beam transmission and wideband; definition and operation of bandwidth portions (BWP); new channel coding methods such as low-density parity-check (LDPC) codes for large data transmissions and polar codes for highly reliable transmission of control information; layer 2 (L2) preprocessing; and network slicing for providing dedicated networks for specific services.

[0004] Currently, regarding the services supported by 5G mobile communication technology, discussions are underway regarding improvements and performance enhancements to the initial 5G mobile communication technology. Physical layer standardization has been completed for technologies such as: Vehicle-to-Everything (V2X) for assisting driving decisions and improving user convenience based on information transmitted by the vehicle regarding its location and status; New Radio Unlicensed Band (NR-U) designed to comply with various regulatory requirements in unlicensed frequency bands for system operation; New Radio (NR) UE power saving; Non-Terrestrial Network (NTN) for direct satellite communication between UEs to ensure coverage in areas where communication with terrestrial networks is not possible; and positioning.

[0005] Furthermore, standardization of air interface architectures / protocols for technologies such as: Industrial Internet of Things (IIoT) for supporting new services through interoperability and integration with other industries; Integrated Access and Backhaul (IAB) for providing nodes for network service area extension by supporting wireless backhaul and access links in an integrated manner; mobility enhancements including conditional handover and Dual Active Protocol Stack (DAPS) handover; and two-step random access (RACH for NR) for simplifying the random access process. Simultaneously, standardization of system architectures / services for technologies such as: 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Virtual Network Functions (NFV) and Software-Defined Networking (SDN) technologies; and Mobile Edge Computing (MEC) for receiving services based on UE location.

[0006] With the commercialization of 5G mobile communication systems, an exponential increase in connected devices will be added to communication networks, thus necessitating enhanced functionality and performance of 5G mobile communication systems and the integrated operation of connected devices. To this end, new research is underway on the following technologies: Extended Reality (XR) for efficient support of Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR), etc.; 5G performance improvements and complexity reductions through the utilization of Artificial Intelligence (AI) and Machine Learning (ML); AI service support; Metaverse service support; and drone communication.

[0007] Furthermore, this development of 5G mobile communication systems will not only lay the foundation for the development of technologies such as: new waveforms for providing coverage in the terahertz band of 6G mobile communication technology; multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and massive MIMO; metamaterial-based lenses and antennas for improving terahertz band signal coverage; high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM); and reconfigurable smart surfaces (RIS), but will also lay the foundation for the development of technologies such as: full-duplex technologies for improving the frequency efficiency of 6G mobile communication technology and improving system networks; AI-based communication technologies for system optimization from the design stage by leveraging satellites and artificial intelligence (AI) and internalizing end-to-end AI support functions; and next-generation distributed computing technologies for providing services at complexity levels exceeding the operational limits of UEs by utilizing ultra-high-performance communication and computing resources.

[0008] The above information is presented as background information only to aid in understanding this disclosure. It is neither determined nor asserted whether any of the above constitutes a prior art application of this disclosure. Summary of the Invention

[0009] Technical issues

[0010] The disclosed embodiments are intended to provide an apparatus and method capable of effectively providing services in a mobile communication system.

[0011] The aspects of this disclosure are intended to at least address the aforementioned problems and / or disadvantages, and to at least provide the advantages described below.

[0012] Problem Solution

[0013] According to one aspect of this disclosure, a method performed by a user equipment (UE) in a communication system is provided. The method includes: transmitting capability information associated with a synchronization sounding reference signal (SRS) carrier handover to a base station; receiving downlink control information (DCI) format from the base station, wherein the DCI format schedules SRSs in component carriers (CCs) for SRS carrier handover, wherein the capability information indicates support for synchronous SRS carrier handover, and the SRSs overlap in time; and transmitting at least one of the scheduled SRSs to the base station for SRS carrier handover.

[0014] According to another aspect of this disclosure, a method performed by a base station in a communication system is provided. The method includes: receiving capability information associated with a Synchronization Sounding Reference Signal (SRS) carrier handover from a user equipment (UE); transmitting downlink control information (DCI) format to the UE, wherein the DCI format schedules the SRS in component carriers (CC) for SRS carrier handover, wherein the capability information indicates support for synchronous SRS carrier handover, and the SRSs overlap in time; and receiving at least one of the scheduled SRSs from the UE for SRS carrier handover.

[0015] According to another aspect of this disclosure, a user equipment (UE) in a communication system is provided. The UE includes a transceiver and at least one processor configured to: transmit capability information associated with Synchronization Sounding Reference Signal (SRS) carrier handover to a base station; receive downlink control information (DCI) format from the base station, wherein the DCI format schedules SRS in component carriers (CC) for SRS carrier handover, wherein the capability information indicates support for synchronous SRS carrier handover, and the SRS overlap in time; and transmit at least one of the scheduled SRS to the base station for SRS carrier handover.

[0016] According to another aspect of this disclosure, a base station in a communication system is provided. The base station includes a transceiver and at least one processor configured to: receive capability information associated with Synchronization Sounding Reference Signal (SRS) carrier handover from a user equipment (UE); transmit downlink control information (DCI) format to the UE, wherein the DCI format schedules SRS in component carriers (CC) for SRS carrier handover, wherein the capability information indicates support for synchronous SRS carrier handover, and the SRS overlap in time; and receive at least one of the scheduled SRS from the UE for SRS carrier handover.

[0017] Beneficial effects

[0018] One aspect of this disclosure provides an apparatus and method for effectively providing services in a mobile communication system.

[0019] Additional aspects will be set forth in part in the description which follows, and in part will be apparent from the description, or may be learned by practice of the presented embodiments.

[0020] Other aspects, advantages, and salient features of this disclosure will become apparent to those skilled in the art from the following detailed description of various embodiments thereof, taken in conjunction with the accompanying drawings. Attached Figure Description

[0021] The above and other aspects, features and advantages of certain embodiments of this disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which: Figure 1 This is a diagram illustrating the basic time-frequency domain structure of a wireless communication system according to an embodiment of the present disclosure; Figure 2 This is a diagram illustrating the structure of frames, subframes, and time slots in a wireless communication system according to embodiments of the present disclosure; Figure 3 This is a diagram illustrating the bandwidth configuration in a wireless communication system according to an embodiment of the present disclosure; Figure 4 This is a diagram illustrating the wireless protocol structure between a UE and a base station in a wireless communication system according to embodiments of the present disclosure, under single-cell, carrier aggregation, and dual-connectivity scenarios; Figure 5 This is a diagram illustrating base station beam allocation based on Transmission Configuration Indicator (TCI) state configuration in a wireless communication system according to an embodiment of the present disclosure; Figure 6 This is a diagram showing the beam application time that can be considered when using a unified TCI scheme in a wireless communication system according to an embodiment of the present disclosure. Figure 7 This is a diagram illustrating a Media Access Control (MAC)-Control Element (CE) structure for activating and indicating a combined TCI state or a separate downlink (DL) or uplink (UL) TCI state in a wireless communication system according to an embodiment of the present disclosure. Figure 8 This is a diagram illustrating the frequency domain resource allocation of the Physical Downlink Shared Channel (PDSCH) or Physical Uplink Shared Channel (PUSCH) in a wireless communication system according to an embodiment of the present disclosure. Figure 9 This is a diagram illustrating the virtual resource block (VRB) - physical resource block (PRB) interleaving scheme of PDSCH in a frequency domain resource allocation (FDRA) type 1 resource allocation according to an embodiment of the present disclosure; Figure 10 This is a diagram illustrating the time-domain resource allocation of the PDSCH in a wireless communication system according to an embodiment of the present disclosure; Figure 11 This is a diagram illustrating an SRS antenna switching operation according to an embodiment of the present disclosure; Figure 12 This is a diagram illustrating SRS carrier switching according to an embodiment of the present disclosure; Figure 13 An aperiodic SRS carrier switching schedule according to an embodiment of the present disclosure is illustrated; Figure 14 This is a diagram illustrating a non-periodic SRS switching for time-of-use resource scheduling according to an embodiment of the present disclosure; Figure 15 This is a diagram illustrating the process of tuning an RF link and transmitting SRS in the case of simultaneous transmission of multiple SRS carrier switching in in-band carrier aggregation (CA) according to an embodiment of the present disclosure. Figure 16 This is a diagram illustrating the process of tuning an RF link and transmitting SRS in the case of simultaneous transmission of multiple SRS carrier switching in inter-band CA according to an embodiment of the present disclosure. Figure 17 Multiple scheduled SRS carrier switchings according to embodiments of the present disclosure are illustrated; Figure 18 This is a diagram illustrating the structure of a UE in a wireless communication system according to an embodiment of the present disclosure; and Figure 19 This is a diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0022] In all the accompanying drawings, the same reference numerals are used to denote the same elements. Detailed Implementation

[0023] The following description, with reference to the accompanying drawings, is provided to aid in a comprehensive understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. The following description includes various specific details to aid understanding, but these details should be considered exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Furthermore, for clarity and brevity, descriptions of well-known functions and structures may be omitted.

[0024] The terms and words used in the following description and claims are not limited to their literal meaning, but are used by the inventors only to enable a clear and consistent understanding of this disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of this disclosure is provided for illustrative purposes only and is not intended to limit the disclosure as defined by the appended claims and their equivalents.

[0025] It should be understood that, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include plural indicators. Thus, for example, referring to “the surface of a component” includes referring to one or more such surfaces.

[0026] The terminology described below is defined based on the functionality of this disclosure and may vary depending on the user's, operator's, or customary intent. Therefore, the definitions of the terms should be determined based on the content throughout this specification.

[0027] In the following text, a base station is an entity that allocates resources to terminals and can be at least one of a gNode B, eNode B, Node B, base station (BS), radio access unit, base station controller, and nodes on a network. A terminal can include a user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. In this disclosure, downlink (DL) refers to a radio link through which a base station transmits signals to a UE, and uplink (UL) refers to a radio link through which a UE transmits signals to a base station. Furthermore, while LTE or LTE-A systems are described exemplarily below, embodiments of this disclosure can also be applied to other communication systems with similar technical backgrounds or channel types. Examples of such communication systems may include 5G, NR, and 5G technologies beyond LTE-A, and 5G can be a concept encompassing existing LTE, LTE-A, or other similar services. Additionally, based on the judgment of those skilled in the art, embodiments of this disclosure can be applied to other communication systems with modifications without significantly departing from the scope of this disclosure.

[0028] In this document, it should be understood that each box in the flowchart illustration, and combinations of boxes in the flowchart illustration, can be executed by computer program instructions. These computer program instructions can be loaded onto the processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for performing the functions specified in the flowchart boxes. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium that can instruct the computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-usable or computer-readable storage medium produce an article of writing including instruction means that perform the functions specified in the flowchart boxes. Computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable data processing apparatus, thereby producing a process executed by the computer, such that the instructions, which execute on the computer or other programmable data processing apparatus, provide steps for performing the functions specified in the flowchart boxes.

[0029] Furthermore, each box can represent a module, code segment, or part of code, including one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the boxes may occur out of order. For example, depending on the functions involved, two boxes shown consecutively may actually execute substantially simultaneously, or these boxes may sometimes execute in reverse order.

[0030] As used in embodiments of this disclosure, "~cell" refers to a software or hardware element that performs a predetermined function, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC). However, "~cell" does not always have a meaning limited to software or hardware. A "~cell" can be configured to be stored in addressable storage media or to execute one or more processors. Therefore, "~cell" includes, for example, software elements, object-oriented software elements, components such as class elements and task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and parameters. Components and functions provided by "~cells" can be combined into a smaller number of components and "~cells," or divided into additional components and "~cells." Furthermore, components and "~cells" can be implemented as one or more CPUs within a playback device or a secure multimedia card. Additionally, in embodiments of this disclosure, "~cell" can include one or more processors.

[0031] Following the initial voice-based services, wireless communication systems have evolved into broadband wireless communication systems that provide high-speed and high-quality packet data services based on communication standards such as 3GPP High-Speed ​​Packet Access (HSPA), LTE (Ever Term Evolution or Evolved Universal Terrestrial Radio Access (E-UTRA)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2 High-Speed ​​Packet Data (HRPD), Ultra Mobile Broadband (UMB), and IEEE 802.16e.

[0032] As a typical example of a broadband wireless communication system, the LTE system employs an Orthogonal Frequency Division Multiplexing (OFDM) scheme in the downlink (DL) and a Single-Carrier Frequency Division Multiple Access (SC-FDMA) scheme in the uplink (UL). The uplink refers to the radio link through which a User Equipment (UE) (or Mobile Station (MS)) transmits data or control signals to a Base Station (BS) (eNode B), and the downlink refers to the radio link through which the Base Station transmits data or control signals to the UE. These multiple access schemes can separate the data or control information of each user by allocating and operating time-frequency resources for transmitting data or control information to each user, thus avoiding overlap and establishing orthogonality.

[0033] As a post-LTE communication system, 5G communication systems must freely reflect the various requirements of users, service providers, and others, and therefore must support services that meet diverse needs. Services considered in 5G communication systems include enhanced mobile broadband (eMBB) communication, massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC), among others.

[0034] eMBB aims to provide higher data rates than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, from the perspective of a single base station, eMBB must provide a peak data rate of 20 Gbps in the downlink and 10 Gbps in the uplink. Furthermore, 5G communication systems must provide increased user-aware data rates and maximum data rates for the UE. To meet these requirements, improved transmit / receive technologies, including further enhanced multiple-input multiple-output (MIMO) transmission techniques, are needed. Moreover, while LTE uses a maximum transmission bandwidth of 20 MHz in the 2 GHz band to transmit signals, 5G communication systems can meet the required data transmission rates by using frequency bandwidths exceeding 20 MHz in the 3 GHz to 6 GHz, or 6 GHz, or larger frequency bands.

[0035] Meanwhile, in 5G communication systems, mMTC is considered to support application services such as the Internet of Things (IoT). mMTC has requirements such as supporting a large number of UEs within a cell, enhancing UE coverage, increasing battery life, and reducing UE costs to effectively deliver IoT. Since IoT provides communication capabilities while being provided to various sensors and devices, it must support a large number of UEs within a cell (e.g., 1,000,000 UEs / km²). Furthermore, UEs supporting mMTC may require wider coverage than other services provided by 5G communication systems because UEs are likely to be located in shaded areas such as building basements, which are not covered by the cell due to the nature of the service. UEs supporting mMTC must be constructed to be inexpensive and may require very long battery lives, such as 10 to 15 years, because frequent battery replacements are difficult.

[0036] Finally, URLLC, as a cellular-based mission-critical wireless communication service, can be considered for applications such as remote control of robots or machines, industrial automation, unmanned aerial vehicles, remote healthcare, and emergency alerts. Therefore, URLLC must provide communication with ultra-low latency and ultra-high reliability. For example, services supporting URLLC should meet an air interface latency of less than 0.5 ms and simultaneously require 10 -5 Or even lower packet error rates. Therefore, for services supporting URLLC, 5G systems must provide shorter transmission time intervals (TTIs) than other services, and may require designs that allocate significant resources within the frequency band to ensure the reliability of communication links.

[0037] Three 5G services (eMBB, URLLC, and mMTC) can be multiplexed and transmitted within a single system. In this case, different transmit / receive technologies and parameters can be used between the services to meet their varying requirements. Clearly, 5G is not limited to these three services.

[0038] In the following text, a / b can be understood as at least one of a and b.

[0039] NR Time and Frequency Resources

[0040] The framework structure of a 5G system will be described below with reference to the accompanying drawings.

[0041] It should be understood that the boxes in each flowchart and the combination of flowcharts can be executed by one or more computer programs that include computer-executable instructions. The entirety of one or more computer programs can be stored in a single memory device, or one or more computer programs can be divided into different parts and stored in different multiple memory devices.

[0042] Any of the functions or operations described herein can be processed by one processor or a combination of processors. A processor or combination of processors is a circuit system that performs processing and includes, for example, an application processor (AP, e.g., a central processing unit (CPU)), a communication processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a Wi-Fi chip, Bluetooth, etc. TM Chips, Global Positioning System (GPS) chips, Near Field Communication (NFC) chips, connectivity chips, sensor controllers, touch controllers, fingerprint sensor controllers, display driver integrated circuits (ICs), audio codec chips, Universal Serial Bus (USB) controllers, camera controllers, image processing ICs, microprocessor units (MPUs), system-on-a-chip (SoCs), ICs, and other circuit systems.

[0043] Figure 1 This is a diagram illustrating the basic structure of a time-frequency domain according to an embodiment of the present disclosure, which is a radio resource domain used for transmitting data or control channels in a 5G system.

[0044] refer to Figure 1 The horizontal domain represents the time domain, and the vertical domain represents the frequency domain. The basic unit of resources in both the time and frequency domains is a resource element (RE) 101, which can be defined as an OFDM symbol 102 along the time domain and a subcarrier 103 along the frequency domain. In the frequency domain, (For example, 12) consecutive REs can constitute a resource block (RB) 104. In the time domain, a subframe 110 can include multiple OFDM symbols 102. For example, the length of a subframe can be 1 ms.

[0045] Figure 2 This is a diagram illustrating the structure of frames, subframes, and time slots in a wireless communication system according to an embodiment of the present disclosure.

[0046] refer to Figure 2 ,exist Figure 2 An example of the structure of frame 200, subframe 201, and time slot 202 is shown. A frame 200 can be defined as 10 ms. A subframe 201 can be defined as 1 ms. Therefore, a frame 200 can include a total of ten subframes 201. A time slot 202 or 203 can be defined as 14 OFDM symbols (i.e., the number of symbols per time slot). =14). A subframe 201 can consist of one time slot or multiple time slots 202 and 203. The number of time slots 202 and 203 in each subframe 201 can vary depending on the configuration values ​​μ 204 and 205 regarding the subcarrier spacing. Figure 2The examples illustrate the cases where the subcarrier spacing configuration value is μ=0 (204) and μ=1 (205). In the case of μ=0 (204), a subframe 201 can consist of one time slot 202. In the case of μ=1 (205), a subframe 201 can consist of two time slots 203. For example, the number of time slots in each subframe... The number of slots per frame can vary depending on the subcarrier spacing configuration value μ. They can be different. and The value μ can be defined based on the configuration of each subcarrier spacing, as shown in Table 1 below: [Table 1]

[0047] Bandwidth Component (BWP)

[0048] The bandwidth portion (BWP) configuration in a 5G communication system will now be described with reference to the accompanying drawings.

[0049] Figure 3 This is a diagram illustrating the bandwidth configuration in a wireless communication system according to an embodiment of the present disclosure.

[0050] Figure 3 The diagram shows that UE bandwidth 300 is configured to include two bandwidth portions (i.e., bandwidth portion #1 (BWP #1) 301 and bandwidth portion #2 (BWP #2) 302). The base station can configure one or more bandwidth portions for the UE, and the following information in Table 2 can be configured for each bandwidth portion.

[0051] [Table 2]

[0052] Clearly, the information configured for the UE is not limited to the examples above, and in addition to the configuration information in Table 2, various parameters related to bandwidth portions can also be configured for the UE. These multiple configuration pieces of information can be transmitted from the base station to the UE via higher-layer signaling (e.g., Radio Resource Control (RRC) signaling). Of the one or more bandwidth portions configured for the UE, at least one bandwidth portion can be activated. Whether the configured bandwidth portion is activated can be semi-statically transmitted from the base station to the UE via RRC signaling, or dynamically transmitted via DCI.

[0053] According to embodiments of this disclosure, a UE prior to RRC connection can be configured as an initial BWP for initial access by the base station via the Master Information Block (MIB). More specifically, the UE can receive configuration information regarding the control resource set (CORESET) and the search space. The Physical Downlink Control Channel (PDCCH), used to receive system information required for initial access via the MIB during the initial access phase (which may correspond to the Remaining System Information (RMSI) or System Information Block 1 (SIB1)), can be transmitted through this search space. Each of the control resource set and the search space configured via the MIB can be considered as ID 0. The base station can notify the UE of configuration information via the MIB, such as frequency allocation information, time allocation information, and parameter sets regarding control resource set #0. Additionally, the base station can notify the UE of configuration information regarding the monitoring period and timing of control resource set #0 via the MIB, i.e., configuration information regarding control resource set #0. The UE can consider the frequency configured by control resource set #0 obtained from the MIB as the initial bandwidth portion for initial access. In this case, the ID of the initial bandwidth portion can be considered as 0.

[0054] The bandwidth-related configurations supported by 5G can be used for a variety of purposes.

[0055] According to some embodiments of this disclosure, when the bandwidth supported by the UE is less than the system bandwidth, this can be supported by bandwidth portion configuration. For example, the base station can configure the frequency position of the bandwidth portion for the UE (configuration information 2), so that the UE can send / receive data at a specific frequency position within the system bandwidth.

[0056] Furthermore, according to embodiments of this disclosure, the base station can configure multiple bandwidth portions for the UE to support different parameter sets. For example, to support the UE in transmitting / receiving data using both 15 kHz and 30 kHz subcarrier intervals, the two bandwidth portions can be configured with subcarrier intervals of 15 kHz and 30 kHz, respectively. The different bandwidth portions can be frequency-division multiplexed (FDM), and when transmitting / receiving data with a specific subcarrier interval, the bandwidth portion configured with the corresponding subcarrier interval can be activated.

[0057] Furthermore, according to some embodiments of this disclosure, the base station can configure bandwidth portions of different sizes for the UE to reduce UE power consumption. For example, when the UE supports a fairly large bandwidth (e.g., 100 MHz) and always uses the corresponding bandwidth to send / receive data, a considerable amount of power consumption may occur. More specifically, from a power consumption perspective, unnecessarily monitoring the downlink control channel with a large bandwidth of 100 MHz when there is no service may be quite inefficient. To reduce UE power consumption, the base station can configure a relatively small bandwidth portion for the UE, such as a bandwidth portion of 20 MHz. The UE can perform monitoring operations in the 20 MHz bandwidth portion when there is no service, and can send / receive data with the 100 MHz bandwidth portion as instructed by the base station when data has been transmitted / received.

[0058] In the method for configuring the bandwidth portion, prior to RRC connection, the UE can receive configuration information regarding the initial bandwidth portion via the MIB during the initial access phase. More specifically, the UE can be configured with a control resource set (i.e., CORESET) for the downlink control channel, through which downlink control information (DCI) for scheduling system information blocks (SIBs) can be transmitted from the MIB of the physical broadcast channel (PBCH). The bandwidth of the control resource set configured via the MIB can be considered as the initial bandwidth portion, and the UE can receive the physical downlink shared channel (PDSCH) through which the SIBs are transmitted via the configured initial bandwidth portion. The initial bandwidth portion can be used not only for receiving SIBs but also for other system information (OSI), paging, and / or random access.

[0059] Changes in the Bandwidth Part (BWP)

[0060] When a UE is configured for one or more bandwidth portions, the base station can instruct the UE to change (or switch or switch) its bandwidth portion by using the bandwidth portion indicator field within the DCI. As an example, the currently active bandwidth portion for the UE is... Figure 3 In the case of bandwidth portion #1 301, the base station can use the bandwidth portion indicator in the DCI to indicate bandwidth portion #2 302, and the UE can perform the change of bandwidth portion to bandwidth portion #2 302 indicated by the bandwidth portion indicator in the received DCI.

[0061] As mentioned above, bandwidth portion changes based on DCI can be indicated by the DCI used for scheduling PDSCH or PUSCH, and when the UE receives a bandwidth portion change request, it needs to be able to receive or transmit the PDSCH or PUSCH scheduled by the corresponding DCI without any problems within the changed bandwidth portion. Therefore, regarding the delay time (T) required during the bandwidth portion change... BWP The requirements are specified standards and can be defined as shown in Table 3 below.

[0062] [Table 3]

[0063] Regarding requests for bandwidth portion delay time changes, either Type 1 or Type 2 is supported, depending on the UE's capabilities. The UE can report the supported bandwidth portion delay time types to the base station.

[0064] Based on the aforementioned requirements regarding the bandwidth partial change delay time, when the UE receives the DCI including the bandwidth partial change indicator in time slot n, the UE can, no later than time slot n+T... BWP The change is completed at the specified time point, switching to the new bandwidth portion indicated by the bandwidth portion change indicator, and data channels scheduled by the corresponding DCI can be transmitted / received within the newly changed bandwidth portion. If the base station wants to use the new bandwidth portion to schedule data channels, it can change the delay time T based on the UE's bandwidth portion. BWP This is used to determine the temporal resource allocation for the data channel. For example, when scheduling a data channel with a new bandwidth portion, in the method for determining the temporal resource allocation for the data channel, the base station can schedule the corresponding data channel after the bandwidth portion change delay time. Therefore, the UE may not expect the DCI indication indicating the bandwidth portion change to be less than the bandwidth portion change delay time T. BWP The time slot offset value K0 or K2.

[0065] If the UE has received a DCI indicating a partial change in bandwidth (e.g., DCI format 1_1 or 0_1), the UE may not perform transmission or reception during the time interval from the third symbol of the slot used to receive the PDCCH that includes the corresponding DCI to the start point of the slot indicated by the slot offset value K0 or K2 indicated by the time domain resource allocation indicator field within the corresponding DCI.

[0066] For example, if the UE receives a DCI indicating a change in bandwidth in time slot n, and the time slot offset value indicated by the corresponding DCI is K, then the UE may not perform transmission or reception from the third symbol of time slot n to the symbols before time slot n+K (i.e., the last symbol of time slot n+K-1).

[0067] Related to CA / Dual Connection (DC)

[0068] Figure 4 This is a diagram illustrating the radio protocol structure of a base station and a UE in single-cell, carrier aggregation, and dual-connectivity scenarios according to embodiments of the present disclosure.

[0069] refer to Figure 4 The wireless protocols of the next-generation wireless communication system include NR Service Data Adaptation Protocol (SDAP) S25 or S70, NR Packet Data Convergence Protocol (PDCP) S30 or S65, NR Radio Link Control (RLC) S35 or S60, and NR Media Access Control (MAC) S40 or S55 in each of the UE and NR base station.

[0070] The main functions of NR SDAP S25 or S70 may include some of the following functions.

[0071] - User data transmission function (transmission of user plane data)

[0072] - Mapping function between uplink and downlink Quality of Service (QoS) streams and data bearers (mapping between QoS streams and data radio bearers (DRB) for both DL and UL)

[0073] - Tagging function for QoS flow IDs in both uplink and downlink (tagging QoS flow IDs in both DL and UL packets)

[0074] - Regarding the mapping function of UL SDAP Protocol Data Unit (PDU) for mapping reflective QoS streams to data bearers (reflective QoS stream to DRB mapping for UL SDAP PDU).

[0075] For SDAP layer entities, the UE can be configured via RRC messages to use either the SDAP layer entity header or its functionality for each PDCP layer entity, bearer, or logical channel. With the SDAP header configured, the SDAP layer entity can instruct the UE to update or reconfigure mapping information related to uplink and downlink QoS flows and data bearers using a Non-Access Stratum (NAS) QoS reflection configuration one-bit indicator (NAS reflected QoS) and an As QoS reflection configuration one-bit indicator (AS reflected QoS) in the SDAP header. The SDAP header may include QoS flow ID information indicating QoS. QoS information can be used as data processing priority information, scheduling information, etc., to smoothly support service.

[0076] The main functions of NR PDCP S30 or S65 may include some of the following functions.

[0077] - Header compression and decompression functions (Header compression and decompression: Robust Header Compression (ROHC) only)

[0078] - User data transmission function (user data transmission)

[0079] - Sequential delivery function (sequential delivery of upper-layer PDUs)

[0080] - Out-of-order delivery function (out-of-order delivery of upper-layer PDUs)

[0081] - Reordering function (PDCP PDU reordering for reception)

[0082] - Duplicate detection function (duplicate detection of lower-level service data units (SDUs))

[0083] - Retransmission function (PDCP SDU retransmission)

[0084] - Encryption and decryption functions (encryption and decryption)

[0085] - Timer-based SDU dropping function (timer-based SDU dropping in the uplink).

[0086] The reordering function of an NR PDCP entity can refer to the function of reordering PDCP PDUs received from the lower layer in order based on the PDCP sequence number (SN), and can include the function of delivering data to the higher layer according to the reordered order. Alternatively, the reordering function of an NR PDCP entity can include the function of delivering data directly regardless of order, the function of reordering to record lost PDCP PDUs, the function of reporting the status of lost PDCP PDUs to the transmission side, and the function of requesting retransmission of lost PDCP PDUs.

[0087] The main functions of NR RLC S35 or S60 may include some of the following functions.

[0088] - Data transmission function (transmission of upper-layer PDUs)

[0089] - Sequential delivery function (sequential delivery of upper-layer PDUs)

[0090] - Out-of-order delivery function (out-of-order delivery of upper-layer PDUs)

[0091] - Automatic Repeat Request (ARQ) function (error correction via ARQ)

[0092] - Cascading, segmentation, and reassembly functions (cascading, segmentation, and reassembly of RLC SDU)

[0093] - Re-segmentation function (re-segmentation of RLC data PDUs)

[0094] - Reordering function (reordering RLC data PDUs)

[0095] - Duplicate detection function (duplicate detection)

[0096] - Error detection function (protocol error detection)

[0097] -RLC SDU discard function (RLC SDU discard)

[0098] -RLC Reconstruction Function (RLC Reconstruction)

[0099] The sequential delivery of NR RLC entities can refer to the function of delivering RLC SDUs received from lower layers to higher layers in sequence. Sequential delivery of NR RLC entities can include: when an original RLC SDU is divided into multiple RLC SDUs and then received, reassembling and delivering the reassembled RLC SDUs; rearranging the order of received RLC SDUs with reference to the RLC sequence number (SN) or PDCP sequence number (SN); rearranging the order to record lost RLC PDUs; reporting the status of lost RLC PDUs to the transmission side; and requesting retransmission of lost RLC PDUs. The sequential delivery function of NR RLC entities can include, in the case of lost RLC SDUs, delivering only the RLC SDUs preceding the lost RLC SDU in sequence to the higher layer, or, if a predetermined timer has expired, delivering all RLC SDUs received before the timer started in sequence to the higher layer even if lost RLC SDUs exist. Alternatively, the in-order delivery function of the NR RLC entity may include the following functionality: despite the existence of lost RLC SDUs, if a predetermined timer has expired, all RLC SDUs received up to the present time will be delivered to the higher layer in sequence. Alternatively, the in-order delivery function of the NR RLC entity may process RLC PDUs in the order they are received (the order in which they arrive, regardless of the sequence number order), and then deliver the processed RLC PDUs to the PDCP entity regardless of the order (out-of-order delivery). In the case of fragmentation, the NR RLC entity may receive fragments stored in a buffer or to be received in the future, reconfigure the fragments into a complete RLC PDU, process the RLC PDU, and deliver the processed RLC PDU to the PDCP entity. The NR RLC layer may not include concatenation functionality, and concatenation functionality may be implemented in the NR MAC layer or replaced by the multiplexing function of the NR MAC layer.

[0100] The out-of-order delivery function of an NR RLC entity can refer to the function of immediately delivering RLC SDUs received from a lower layer to a higher layer, regardless of their order, and can include the following functions: in the case that an original RLC SDU is divided into multiple RLC SDUs and then the multiple RLC SDUs are received, reassembling the multiple RLC SDUs and delivering the reassembled RLC SDUs; and storing the RLC SN or PDCP SN of the received RLC PDUs and arranging them in order to record lost RLC PDUs.

[0101] NR MAC S40 or S55 can be connected to several NR RLC layer entities that constitute a single UE, and the main functions of NR MAC can include some of the following functions.

[0102] - Mapping function (mapping between logical channels and transmission channels)

[0103] - Multiplexing and demultiplexing functions (MAC SDU multiplexing / demultiplexing)

[0104] - Scheduling information reporting function (Scheduling Information Report)

[0105] - Hybrid Automatic Repeat Request (HARQ) function (error correction via HARQ)

[0106] - Priority processing function between logical channels (priority processing between logical channels of a UE)

[0107] - Priority handling function between UEs (using dynamic scheduling for priority handling between UEs)

[0108] - Multimedia Broadcast / Multicast Service (MBMS) Service Identification Function (MBMS Service Identifier)

[0109] -Transmission format selection function (Transmission format selection)

[0110] - Fill function (Fill)

[0111] The NR physical (PHY) layer S45 or S50 can perform channel coding and modulation of higher-layer data to form orthogonal frequency division multiplexing (OFDM) symbols and transmit OFDM symbols over a wireless channel, or it can perform demodulation and channel decoding of OFDM symbols received over a wireless channel and then deliver the OFDM symbols to higher layers.

[0112] The detailed structure of the wireless protocol architecture can vary depending on the carrier (or cell) operation scheme. For example, when the base station transmits data to the UE based on a single carrier (or cell), the base station and the UE use a protocol architecture with a single structure at each layer, as shown in S00. Conversely, when the base station transmits data to the UE based on carrier aggregation (CA) using multiple carriers at a single TRP, the base station and the UE use a protocol architecture with a single structure up to RLC, but multiplex the PHY layer through the MAC layer, as shown in S10. As another example, when the base station transmits data to the UE based on dual connectivity (DC) using multiple carriers at multiple TRPs, the base station and the UE use a protocol architecture with a single structure up to RLC, but multiplex the PHY layer through the MAC layer, as shown in S20.

[0113] Quasi-common address (QCL), TCI state

[0114] One or more distinct antenna ports (or one or more channels, signals, and combinations thereof, which may be used as alternatives, but for ease of explanation, are collectively referred to as distinct antenna ports in the following description of this disclosure) can be associated with each other in a wireless communication system through a quasi-co-location (QCL) configuration shown in Table 4 below. The TCI state is used to inform the PDCCH (or PDCCH demodulation reference signal (DMRS)) of the QCL relationship between distinct RSs or channels. Quasi-co-location (QCL) between a reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) means that the UE is allowed to apply all or some of the large-scale channel parameters estimated in antenna port A to perform channel measurements in antenna port B. Depending on the following scenarios, the QCL may need to associate different parameters: 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. Therefore, NR supports the four types of QCL relationships shown in Table 4 below.

[0115] [Table 4]

[0116] Spatial RX parameters can indicate some or all of a variety of parameters, including angle of arrival (AoA), power angle spectrum (PAS) of AoA, angle of departure (AoD), PAS of AoD, transmit / receive channel correlation, transmit / receive beamforming, and spatial channel correlation.

[0117] QCL relationships can be configured for the UE via the RRC parameters TCI-State and QCL-Info, as shown in Table 9 below. Referring to Table 5, the base station can configure one or more TCI states for the UE, thereby notifying the RS (i.e., the target RS) of the reference TCI state ID of up to two types of QCL relationships (qcl-Type1 and qcl-Type2). In this case, each QCL information (QCL-Info) contained in each TCI state may include the serving cell index and BWP index of the reference RS, as well as the type and ID of the reference RS indicated by the corresponding QCL information, and the QCL type described in Table 4 above.

[0118] [Table 5]

[0119] Figure 5 This is a diagram illustrating base station beam allocation configured according to TCI state according to an embodiment of the present disclosure.

[0120] refer to Figure 5 The base station can transmit information about N different beams to the UE through N different TCI states. For example, such as Figure 5 As shown, with N=3, the base station can allow the qcl-Type2 parameters included in the three TCI states 500, 505 and 510 to be associated with the CSI-RS or SSB corresponding to different beams and configured as QCL type D to notify the antenna ports referencing different TCI states 500, 505 and 510 to be associated with different spatial Rx parameters (i.e., different beams).

[0121] Tables 6 through 10 below show the valid TCI state configurations based on the type of the target antenna port.

[0122] Table 6 shows the valid TCI state configurations when the target antenna port is a CSI-RS for tracking (i.e., TRS). TRS can refer to an NZP CSI-RS with unconfigured repeat parameters and trs-Info configured as true. Configuration #3 in Table 10 can be used for aperiodic TRS.

[0123] Effective TCI state configuration when the target antenna port is a CSI-RS (TRS) for tracking.

[0124] [Table 6]

[0125] Table 7 shows the valid TCI state configuration when the target antenna port is a CSI-RS for tracking. The CSI-RS for CSI can refer to a CSI-RS in which no repeating indicator is configured (e.g., repeating parameter) and trs-Info is not configured as a true NZP CSI-RS.

[0126] The TCI state configuration is valid when the target antenna port is a CSI-RS for CSI.

[0127] [Table 7]

[0128] Table 8 shows the valid TCI status configuration when the target antenna port is a CSI-RS for beam management (BM) (which is the same as the CSI-RS for L1 RSRP reporting). The CSI-RS for BM can be an NZP CSI-RS in which the repeat parameter is configured and has an on or off value and trs-Info is not configured as true.

[0129] The TCI state configuration is valid when the target antenna port is for BM's CSI-RS (for L1 RSRP reporting).

[0130] [Table 8]

[0131] Table 9 shows the effective TCI state configuration when the target antenna port is PDCCH DMRS.

[0132] Effective TCI state configuration when the target antenna port is PDCCH DMRS.

[0133] [Table 9]

[0134] Table 10 shows the effective TCI state configuration when the target antenna port is PDSCH DMRS.

[0135] Effective TCI state configuration when the target antenna port is PDSCH DMRS.

[0136] [Table 10]

[0137] In the representative QCL configuration methods according to Tables 6 to 10, the target antenna port and reference antenna port at each stage are configured as "SSB" → "TRS" → "CSI-RS for CSI, CSI-RS for BM, PDCCH DMRS, or PDSCHDMRS" and operated. In this way, the UE's reception operation can be assisted by associating statistical characteristics measurable by SSB and TRS with the corresponding antenna ports.

[0138] Unified TCI Status

[0139] The following describes a method for indicating and activating a single TCI state based on a unified TCI scheme. A unified TCI scheme can refer to a scheme that manages both transmit and receive beam management schemes holistically through TCI states. Transmit and receive beam management schemes have been categorized in Rel-15 and 16 of related technologies as TCI state schemes for downlink reception of the UE and spatial relationship information schemes for uplink transmission. Therefore, when the UE receives an indication from the base station, based on the unified TCI scheme, the UE can perform beam management, even for uplink transmission, by using TCI states. If the base station configures a higher-layer signaling TCI-State with higher-layer signaling tci-stateId-r17 for the UE, the UE can perform operations based on the unified TCI scheme by using the corresponding TCI-State. TCI-States can exist in two types: joint TCI states or individual TCI states.

[0140] The first type is a joint TCI state, where the base station can indicate to the UE all TCI states to be applied to uplink transmission and downlink reception using a single TCI state. If a TCI-State based on a joint TCI state is indicated to the UE, the parameters to be used for downlink channel estimation can be indicated by using the RS corresponding to qcl-Type1 in the corresponding joint TCI-State, and the parameters to be used as the downlink receive beam or receive filter can be indicated by using the RS corresponding to qcl-Type2. If a TCI-State based on a joint TCI state is indicated to the UE, the parameters to be used as the uplink transmission beam or transmission filter can be indicated by using the RS corresponding to qcl-Type2 in the corresponding joint DL / UL TCI-State. In this case, when the UE is indicated to have a joint TCI state, the UE can apply the same beam to both uplink transmission and downlink reception.

[0141] The second type is a separate TCI state, where the base station can indicate to the UE separately the UL TCI state to be applied to uplink transmission and the DL TCI state to be applied to downlink reception. If the UL TCI state is indicated to the UE, the parameters to be used as the uplink transmission beam or transmission filter can be indicated to the UE using the reference RS or source RS configured in the corresponding UL TCI state. If the DL TCI state is indicated to the UE, the parameters to be used for downlink channel estimation can be indicated to the UE using the RS corresponding to qcl-Type1 in the corresponding DL TCI state, and the parameters to be used as the downlink receive beam or receive filter can be indicated using the RS corresponding to qcl-Type2.

[0142] If the DL TCI state and UL TCI state are indicated to the UE, the parameters to be used as uplink transmission beams or transmission filters can be indicated to the UE using a reference RS or source RS configured in the corresponding UL TCI state, the parameters to be used for downlink channel estimation can be indicated using an RS corresponding to qcl-Type1 configured in the corresponding DL TCI state, and the parameters to be used as downlink receive beams or receive filters can be indicated using an RS corresponding to qcl-Type2. In this case, if the reference RS or source RS configured in the DL TCI state and UL TCI state indicated to the UE are different from each other, the UE can apply separate beams for uplink transmission and downlink reception based on the DL TCI state and UL TCI state indicated to the UE.

[0143] Up to 128 joint TCI states can be configured for the UE by the base station via higher-layer signaling for each specific bandwidth portion within a specific cell. Within individual TCI states, based on the UE capability report, up to 64 or 128 DL TCI states can be configured via higher-layer signaling for each specific bandwidth portion within a specific cell, and the DL TCI states for individual TCI states and joint TCI states can use the same higher-layer signaling structure. For example, if 128 joint TCI states are configured, and 64 DL TCI states are configured as individual TCI states, then the 64 DL TCI states can be included in the 128 joint TCI states.

[0144] Within a standalone TCI state, based on the UE capability report, the UL TCI state can be configured to a maximum of 32 or 64 states via higher-layer signaling for each specific bandwidth portion within a specific cell. Similar to the relationship between the DL TCI state and the joint TCI state in a standalone TCI state, the UL TCI state in a standalone TCI state can use the same higher-layer signaling structure as the joint TCI state. However, the UL TCI state in a standalone TCI state can use a different higher-layer signaling structure than the joint TCI state or the DL TCI state in a standalone TCI state.

[0145] As mentioned above, the specification can define the use of different or the same higher-layer signaling structures. The use of different or the same higher-layer signaling structures can be determined by another higher-layer signaling configured by the base station based on a UE capability report that includes information about the use cases that the UE can support in both types of use cases.

[0146] The UE can receive transmit / receive beam-related indications in a unified TCI scheme by using either a joint TCI state or a separate TCI state configured by the base station. Whether to use either the joint TCI state or the separate TCI state can be configured by the base station for the UE via higher-layer signaling.

[0147] The UE can receive transmit / receive beam-related indications via higher-layer signaling by using a scheme selected from the joint TCI state and the individual TCI state. In this case, the base station's transmit / receive beam-related indication method can be classified into two methods: a MAC-CE-based indication method and a MAC-CE-based activation and DCI-based indication method.

[0148] When the UE receives transmit / receive beam-related indications via higher-layer signaling using a joint TCI state scheme, the UE can receive a MAC-CE indicating the joint TCI state from the base station to perform transmit / receive beam application operations, and the base station can schedule the reception of a PDSCH including the corresponding MAC-CE to the UE via the PDCCH. If the MAC-CE includes one joint TCI state, the UE can determine the uplink transmit beam or transmit filter and the downlink receive beam or receive filter by using the indicated joint TCI state after 3 ms from the start of the PUCCH transmission including HARQ-ACK information indicating whether the PDSCH containing the corresponding MAC-CE has been successfully received. If the MAC-CE includes two or more joint TCI states, the UE can identify the corresponding code points of the TCI state field in DCI format 1_1 or 1_2 corresponding to the multiple joint TCI states indicated by the MAC-CE after 3 ms from the start of the PUCCH transmission including HARQ-ACK information indicating whether the PDSCH containing the corresponding MAC-CE has been successfully received. Subsequently, the UE may receive DCI format 1_1 or 1_2 to apply a joint TCI state indicated by the TCI state field within the corresponding DCI to the uplink transmit beam and downlink receive beam. In this case, DCI format 1_1 or 1_2 may include downlink data channel scheduling information (with DL allocation), or may not include such downlink data channel scheduling information (without DL allocation).

[0149] When a UE receives transmit / receive beam-related indications via higher-layer signaling using a separate TCI state scheme, the UE can receive a MAC-CE indicating the separate TCI state from the base station to perform transmit / receive beam application operations. The base station can schedule the reception of a PDSCH including the corresponding MAC-CE to the UE via the PDCCH. If the MAC-CE includes a separate TCI state set, the UE can determine the uplink transmit beam or transmit filter and the downlink receive beam or receive filter by using the separate TCI states included in the indicated separate TCI state set after 3 ms from the start of the PUCCH transmission including HARQ-ACK information indicating whether the corresponding PDSCH has been successfully received. In this case, a separate TCI state set can refer to one or more separate TCI states that a code point of the TCI state field in DCI format 1_1 or 1_2 can have. A separate TCI state set can include a DL TCI state, include a UL TCI state, or include a DLTCI state and a UL TCI state. If the MAC-CE includes two or more individual TCI state sets, the UE can identify the corresponding code points of the TCI state fields in DCI format 1_1 or 1_2 corresponding to the multiple individual TCI state sets indicated by the MAC-CE 3 ms after the transmission of the PUCCH including HARQ-ACK information indicating whether the corresponding PDSCH has been successfully received, and can activate the indicated individual TCI state sets. In this case, each code point of the TCI state field in DCI format 1_1 or 1_2 can indicate a DL TCI state, an UL TCI state, or both a DL TCI state and an UL TCI state. The UE can receive DCI format 1_1 or 1_2 to apply the individual TCI state sets indicated by the TCI state fields in the corresponding DCI to the uplink transmission beam and downlink receive beam. In this case, DCI format 1_1 or 1_2 may include downlink data channel scheduling information (with DL allocation) or may not include such downlink data channel scheduling information (without DL allocation).

[0150] Figure 6 This is a diagram showing the beam application time that can be considered when using a unified TCI scheme in a wireless communication system according to an embodiment of the present disclosure.

[0151] refer to Figure 6As described above, the UE can receive DCI format 1_1 or 1_2 from the base station, which includes downlink data channel scheduling information (with DL allocation) or does not include downlink data channel scheduling information (without DL allocation), and can apply a joint TCI state or a single TCI state set indicated by the TCI state field in the corresponding DCI to the uplink transmission beam and the downlink reception beam.

[0152] With DCI format 1_1 or 1_2 of DL allocation 6-00: When the UE receives DCI format 1_1 or 1_2 from the base station, which includes downlink data channel scheduling information 6-01 indicating a joint TCI state or a single TCI state set based on a unified TCI scheme, the UE can receive PDSCH scheduled based on the received DCI 6-05 and transmit PUCCH (6-10) including HARQ-ACK indicating whether the DCI and PDSCH were successfully received. In this case, HARQ-ACK can include whether both the DCI and PDSCH were successfully received. If the UE fails to receive at least one of the DCI and PDSCH, the UE can transmit NACK; if the UE successfully receives both, the UE can transmit ACK.

[0153] DCI format 1_1 or 1_2 without DL allocation 6-50: When the UE receives DCI format 1_1 or 1_2 from the base station that does not include downlink data channel scheduling information 6-55, indicating a joint TCI state or a single TCI state set based on a unified TCI scheme, the UE may assume at least one combination of the following for the corresponding DCI.

[0154] This includes Cyclic Redundancy Check (CRC) scrambled using Carrier Selected Radio Network Temporary Identifier (CS-RNTI).

[0155] All bits in all fields assigned to the redundant version (RV) field are set to 1.

[0156] All bits assigned to all fields used as modulation and coding scheme (MCS) fields are set to 1.

[0157] All bits assigned to all fields used as New Data Indicator (ND) fields are set to 0.

[0158] In the case of Frequency Domain Resource Allocation (FDRA) type 0, all bits assigned to the FDRA field have a value of 0. In the case of FDRA type 1, all bits assigned to the FDRA field have a value of 1. And in the case of FDRA scheme dynamicSwitch, all bits assigned to the FDRA field have a value of 0.

[0159] Assuming the above items 6-60, the UE can transmit a PUCCH containing a HARQ-ACK indicating whether it has been successfully received in DCI format 1_1 or 1_2.

[0160] For both DCI formats 1_1 and 1_2 with and without DL allocation 6-00, if the new TCI state indicated by DCI 6-01 or 6-55 is the same as the previously indicated TCI state applied to the uplink transmit and downlink receive beams, the UE can maintain the previously applied TCI state. If the new TCI state is different from the previously indicated TCI state, the UE can determine the time point 6-30 or 6-80 after the first time slot 6-20 or 6-70 following the PUCCH transmission, after a time interval of up to Beam Application Time (BAT) 6-15 or 6-65, as the time point for applying the joint TCI state or a set of individual TCI states (which can be indicated by the TCI state field included in the DCI). The UE can use the previously indicated TCI state at the time point 6-25 or 6-75 before the corresponding time slot 6-20 or 6-70.

[0161] For both DCI formats 1_1 and 1_2 with and without DL allocation 6-00, BAT is a specific number of OFDM symbols and can be configured via higher-layer signaling based on UE capability report information. The parameter set of BAT and the first time slot following BAT can be determined based on the minimum parameter set among all cells that have applied the joint TCI state or individual TCI state set indicated by DCI.

[0162] The UE can apply a joint TCI state indicated by MAC-CE or DCI to the reception of control resource sets connected to all UE-specific search spaces, apply the joint TCI state to the reception of PDSCH and the transmission of PUSCH, the PDSCH and PUSCH are scheduled by the PDCCH transmitted in the corresponding control resource sets, and apply the joint TCH state to the transmission of all PUCCH resources.

[0163] When a single TCI state set indicated via MAC-CE or DCI includes a DL TCI state, the UE may apply the single TCI state set to the reception of control resource sets connected to all UE-specific search spaces, and apply the single TCI state set to the reception of PDSCHs scheduled by PDCCHs transmitted in the control resource set. The UE may apply the previously indicated UL TCI state to all PUSCH and PUCCH resources.

[0164] If a single TCI state set indicated by MAC-CE or DCI includes a UL TCI state, the UE can apply the UL TCI state to all PUSCH and PUCCH resources. The UE can apply a previously indicated DL TCI state to receive control resource sets connected to all UE-specific search spaces, and to receive PDSCHs scheduled by PDCCHs transmitted in the corresponding control resource sets.

[0165] When a single TCI state set indicated by MAC-CE or DCI includes one DL TCI state and one ULTCI state, the UE may apply the DL TCI state to receive control resource sets connected to all UE-specific search spaces, and to receive PDSCHs scheduled by PDCCHs transmitted in the control resource set. The UE may apply the ULTCI state to all PUSCH and PUCCH resources.

[0166] Unified TCI Status MAC-CE

[0167] The following describes a single TCI state indication and activation method based on a unified TCI scheme. The base station can schedule a PDSCH including the MAC-CE as described below to the UE, and after three time slots following the transmission of the HARQ-ACK for the corresponding PDSCH to the base station, the UE 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. For example, the UE can activate each entry of the MAC-CE received from the base station in each code point of the TCI state field in DCI format 1_1 or 1_2.

[0168] Figure 7 This is a diagram illustrating a MAC-CE structure in a wireless communication system according to an embodiment of the present disclosure, used for activating and indicating a combined TCI state or a separate DL or UL TCI state. Each field in the corresponding MAC-CE structure may have the following meaning.

[0169] refer to Figure 7Serving Cell ID 7-00: This field indicates which serving cell the corresponding MAC-CE should be applied to. This field can be 5 bits long. If the serving cell indicated by this field can be included in one or more of the higher-layer signaling lists simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3, and simultaneousU-TCI-UpdateList4, then the corresponding MAC-CE can be applied to all serving cells included in one or more of these lists, including the serving cell indicated by this field.

[0170] DL BWP ID 7-05: This field indicates which DL BWP the corresponding MAC-CE applies to, and the meaning of each code point in this field corresponds to each code point in the bandwidth section indicator in the DCI. This field can be 2 bits long.

[0171] UL BWP ID 7-10: This field indicates which UL BWP the corresponding MAC-CE applies to, and the meaning of each code point in this field corresponds to each code point in the bandwidth section indicator in the DCI. This field can be 2 bits long.

[0172] P i 7-15: This field can indicate whether each code point in the TCI status field of DCI format 1_1 or 1_2 has multiple TCI statuses or one TCI status. If P i If the value of is 1, this indicates that the corresponding i-th code point has multiple TCI states, and may imply that the corresponding code point can include a single DL TCI state and a single UL TCI state. If P i If the value is 0, it indicates that the corresponding i-th code point has a single TCI state, and may imply that the corresponding code point may include one of a joint TCI state, a single DL TCI state, or a single UL TCI state.

[0173] D / U 7-20: This field indicates whether the TCI status ID field in the same octet is a combined TCI status, a separate DL TCI status, or a separate UL TCI status. If this field is 1, the TCI status ID field in the same octet can be a combined TCI status or a separate DL TCI status. If this field is 0, the TCI status ID field in the same octet can be a separate UL TCI status.

[0174] TCI State ID 7-25: This field indicates the TCI state that can be identified by the higher-layer signaling TCI-StateID. When the D / U field is configured to 1, this field can be used to represent the TCI-StateID, which can be represented by 7 bits. When the D / U field is configured to 0, the most significant bit (MSB) of this field can be considered a reserved bit, and the remaining 6 bits can be used to represent the higher-layer signaling UL-TCIState-ID. In the case of combined TCI states, the maximum number of active TCI states can be 8, and in the case of individual DL or UL TCI states, it can be 16.

[0175] R 7-30: This indicates a reserved bit and can be configured to 0.

[0176] Regarding the above-mentioned Figure 7 The MAC-CE structure allows the UE to include... Figure 7 The third octet in the MAC-CE configuration (including fields P1, P2, ..., P8) is used regardless of whether the unifiedTCI-StateType-r17 in the MIMOparam-r17 of the higher-layer signaling ServingCellConfig is configured as unified or separate. In this case, the UE can perform TCI state activation by using a fixed MAC-CE structure, regardless of the higher-layer signaling configured by the base station. As another example, for the above... Figure 7 In the MAC-CE structure, if the unifiedTCI-StateType-r17 of MIMOparam-r17 in the higher-layer signaling ServingCellConfig is configured as united, the UE can omit... Figure 7 The third octet (including P1, P2, ..., P8 fields) in the data. In this case, the UE can save up to 8 bits of the corresponding MAC-CE payload according to the higher-layer signaling configured by the base station. Furthermore, from the location... Figure 7 All D / U fields in the first bit of the octet starting from the fourth octet can be regarded as R fields, and all corresponding R fields can be configured to 0 bits.

[0177] PDCCH: Related DCI

[0178] The following section will describe downlink control information (DCI) in 5G systems.

[0179] In 5G systems, scheduling information on uplink data (or physical uplink data channel (PUSCH)) or downlink data (or physical downlink data channel (PDSCH)) is transmitted from the base station to the UE via DCI. The UE can monitor the back-off DCI format and the non-back-off DCI format of the PUSCH or PDSCH. The back-off DCI format can consist of fixed fields predefined between the base station and the UE, while the non-back-off DCI format can include configurable fields.

[0180] The DCI message undergoes channel coding and modulation before being transmitted via the Physical Downlink Control Channel (PDCCH), which serves as the physical downlink control channel. Cyclic Redundancy Check (CRC) can be appended to the DCI message payload, and the CRC can be scrambled using a Radio Network Temporary Identifier (RNTI) corresponding to the UE's identity. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. For example, the RNTI is not explicitly transmitted but is transmitted after being included in the CRC calculation process. If the UE receives a DCI message transmitted on the PDCCH, it can identify the CRC using the assigned RNTI, and if the CRC identification is correct, the UE can recognize that the corresponding message has been transmitted to it.

[0181] For example, the DCI for scheduling PDSCH for System Information (SI) can be scrambled by SI-RNTI. The DCI for scheduling PDSCH for Random Access Response (RAR) messages can be scrambled by RA-RNTI. The DCI for scheduling PDSCH for paging messages can be scrambled by P-RNTI. The DCI for notifying Slot Format Indicator (SFI) can be scrambled by SFI-RNTI. The DCI for notifying Transmission Power Control (TPC) can be scrambled by TPC-RNTI. The DCI for scheduling UE-specific PDSCH or PUSCH can be scrambled by Cell RNTI (C-RNTI).

[0182] DCI format 0_0 can be used as a backoff DCI for scheduling PUSCH, and in this case, the CRC can be scrambled by C-RNTI. DCI format 0_0 with a CRC scrambled by the Cell Radio Network Temporary Identifier (C-RNTI) can include, for example, several pieces of information as shown in Table 11 below.

[0183] [Table 11]

[0184] DCI format 0_1 ​​can be used as a non-back-off DCI for scheduling PUSCH, and in this case, the CRC can be scrambled by C-RNTI. DCI format 0_1 ​​with a CRC scrambled by C-RNTI can include multiple pieces of information, such as those shown in Table 12 below.

[0185] [Table 12]

[0186] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, and in this case, the CRC can be scrambled by C-RNTI. DCI format 1_0 with a CRC scrambled by C-RNTI can include multiple pieces of information, such as those shown in Table 13 below.

[0187] [Table 13]

[0188] DCI format 1_1 can be used as a non-back-off DCI for scheduling PDSCH, and in this case, the CRC can be scrambled by C-RNTI. DCI format 1_1 with a CRC scrambled by C-RNTI can include multiple pieces of information, such as those shown in Table 14 below.

[0189] [Table 14]

[0190] PDSCH / PUSCH: Related to frequency resource allocation

[0191] Next, we will describe the frequency domain resource allocation (FDRA) of the Physical Downlink Shared Channel (PDSCH) and Physical Uplink Shared Channel (PUSCH) in NR.

[0192] Figure 8 This is a diagram illustrating the frequency domain resource allocation of PDSCH or PUSCH in a wireless communication system according to an embodiment of the present disclosure.

[0193] refer to Figure 8 The diagram illustrates three frequency domain resource allocation methods in NR wireless communication systems: FDRA type 0800, FDRA type 1 805, and dynamic switching 810, which can be configured by higher layers.

[0194] refer to Figure 8When a UE is configured to use only FDRA type 0 800 via higher-layer signaling, the downlink control information (DCI) for scheduling PDSCH or PUSCH for the corresponding UE may include information from N. RBG A bitmap composed of units. Its conditions will be described later. In this case, N RBG This can refer to the number of Resource Block Groups (RBGs), as shown in Table 15 below, determined by the higher-level parameter rbg-Size and the BWP size allocated by the BWP indicator. Data is transmitted on the RBG marked as 1 according to the bitmap.

[0195] [Table 15]

[0196] The size of frequency resources in the bandwidth portion can be defined as the number of RBs contained in the bandwidth portion. More specifically, when the UE is instructed to allocate FDRA type-0 resources, the FDRA field length of the DCI received by the UE is equal to the number of RBs (N) in the bandwidth portion. RBG The quantity is the same, and it is Here, the first RBG in the bandwidth section includes RB, and if The last RBG in the bandwidth section includes One RB, otherwise, the last RBG in the bandwidth section includes There are P RBs. The remaining RBG in the bandwidth portion comprises P RBs. Here, P is the number of nominal RBGs determined according to Table 15 above.

[0197] When the UE is configured to use only FDRA Type 1 via higher-level signaling 805, the DCI assigned to the UE for PDSCH or PUSCH includes... The unit-level frequency domain resource allocation information (FDRA). Here... This refers to the number of RBs included in the bandwidth portion. With this information, the base station can configure the length of the starting VRB 820 and the frequency domain resources 825 sequentially allocated from it.

[0198] If the UE is not configured with the higher-layer signaling vrb-ToPRB-Interleaver, the UE can associate resources allocated to the VRB with the PRB without interleaving. When the UE is configured with the higher-layer signaling vrb-ToPRB-Interleaver, the corresponding higher-layer signaling has a value of 2 or 4, and this value can be a unit of multiple RBs performing interleaving. For example, a bundle of 2 or 4 RBs can be used for interleaving.

[0199] When the UE is configured to be from The i-th BWP starting from position i, and including in length One RB, and vrb-ToPRB-Interleaver is configured as In this case, the UE can divide the i-th BWP into RB bundles, and each RB bundle may include RB.

[0200] In the i-th BWP, the first RB bundle may include RB.

[0201] In the i-th BWP, When the value is greater than 0, the last RB bundle can include RB, otherwise, it can be generated by It consists of RBs.

[0202] In the i-th BWP, the remaining RB bundles may include RB.

[0203] In this case, the VRB can be associated with the PRB using the following method.

[0204] The last VRB bundle can be associated with the last PRB bundle.

[0205] The j-th (j=0, 1, ..., VRB bundling can be combined with the first f(j) Each PRB bundle is associated with another, and f(j) It can be expressed as Equation 1 below.

[0206] [Equation 1]

[0207] Figure 9 This is a diagram illustrating the VRB-PRB interleaving scheme of PDSCH in an FDRA type-1 resource allocation according to an embodiment of the present disclosure.

[0208] refer to Figure 9 The diagram illustrates a case 910 in which the first and last VRB bundles in a BWP 900 comprising 10 RBs both include one VRB. Therefore, the number of VRB bundles... It can be 6, and can be calculated using Equation 1 above. Therefore, since the j-th VRB bundle can be associated with the f(j)-th PRB bundle through Equation 1 above, the association from VRB bundle to PRB bundle can be performed using the result 930 calculated by Equation 1 above, as shown in reference numeral 920 in the figure. For example, VRB bundle 1 940 can be associated with PRB bundle 3 950.

[0209] When a UE is configured to use both FDRA type-0 and FDRA type-1 resource allocations simultaneously via higher-layer signaling, some DCIs allocated to the corresponding UE for PDSCH / PUSCH include frequency domain resource allocation information consisting of the larger of the payload 815 for configuring FDRA type-0 resource allocation and the larger of the payloads 820 and 825 for configuring FDRA type-1 resource allocation, value 835. The conditions will be described later. In this case, a bit 830 can be added to the first part (MSB) of the frequency domain resource allocation information in the DCI, and a value of "0" in the corresponding bit indicates the use of FDRA type-0 resource allocation, while a value of "1" in the corresponding bit indicates the use of FDRA type-1 resource allocation.

[0210] When a UE is configured to use the FDRA type-2 resource allocation method via higher-layer signaling, the base station can instruct the UE regarding the FDRA type-2 resource allocation method according to the following method.

[0211] The base station can instruct the UE about RB allocation information, which is a set of M interleaving indices.

[0212] Intertwined Index Can be made by public RB The composition, and M can be defined as shown in Table 16.

[0213] [Table 16]

[0214] RB in interlacing m With bandwidth portion i and common RB The relationship between them can be defined as follows.

[0215]

[0216] in It is the bandwidth portion of the common resource block relative to common resource block 0. u is the subcarrier interval index.

[0217] When the subcarrier spacing is 15 kHz (u=0), the base station can use m0 + l indices to notify the UE of the RB allocation information of the interleaving set. Furthermore, the resource allocation field can be composed of resource individualization values ​​(RIV). When the resource individualization value is... hour, It can be determined by the initial interleaving code m0 and the number of consecutive interleavings. ( It consists of ) and its values ​​are as follows.

[0218]

[0219] When the individual value of resources At that time, the resource individualization value is composed of the initial interleaving index m0 and the l value, and can be constructed as shown in Table 17.

[0220] [Table 17]

[0221] When the subcarrier spacing is 30 kHz (u=1), RB allocation information can be notified to the UE from the base station in the form of a bitmap indicating the interleaving allocated to the UE. The bitmap is of size M, and each bit of the bitmap corresponds to an interleaving. The order of the interleaving bitmap can be mapped from MSB to LSB, and from interleaving index 0 to interleaving index M-1.

[0222] In addition, for 15 kHz and 30 kHz, the least significant bit (LSB) of the FDRA field. This can represent a contiguous set of RBs for PUSCHs scheduled in DCI format 0_1. The Y bit can be composed of resource indicator values ​​(RIVRBset). middle, The RIVRBset value can be determined by the initial RB set (RBset). START ) and the number of consecutive RB sets ( The RIVRBset value can be defined as follows.

[0223] It refers to the number of RB sets included in the bandwidth portion, and can be determined by the number of guard gaps (or bands) within the carrier configured (or pre-configured) by higher-layer signaling.

[0224] PDSCH / PUSCH: Related to time resource allocation

[0225] The following describes a method for allocating time-domain resources for data channels in next-generation mobile communication systems (5G or NR systems).

[0226] The base station can configure tables for the UE related to the time-domain resource allocation information of the downlink data channel (PDSCH) and uplink data channel (PUSCH) via higher-layer signaling (e.g., RRC signaling). A table with a maximum of 16 entries (maxNrofDL-Allocations=16) can be configured for the PDSCH, and a table with a maximum of 16 entries (maxNrofUL-Allocations=16) can be configured for the PUSCH. In embodiments of this disclosure, time-domain resource allocation information may include PDCCH-to-PDSCH time slot timing (which corresponds to the time interval represented by time slots between the time point of receiving the PDCCH and the time point of transmitting the PDSCH scheduled by the received PDCCH, and may be represented by K0), PDCCH-to-PUSCH time slot timing (which corresponds to the time interval represented by time slots between the time point of receiving the PDCCH and the time point of transmitting the PUSCH scheduled by the received PDCCH, and may be represented by K2), information regarding the starting symbol position and length of the PDSCH or PUSCH scheduled within the time slot, PDSCH or PUSCH mapping type, etc. For example, the information shown in Table 18 or Table 19 below can be sent from the base station to the UE.

[0227] [Table 18]

[0228] [Table 19]

[0229] The base station can notify the UE of one of the entries in the table related to time-domain resource allocation information mentioned above via L1 signaling (e.g., DCI) (e.g., it can be indicated by the "Time-domain Resource Allocation" field in the DCI). The UE can obtain the time-domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

[0230] Figure 10 This is a diagram illustrating the time-domain resource allocation of the PDSCH in a wireless communication system according to an embodiment of the present disclosure.

[0231] refer to Figure 10 The base station can be based on the subcarrier spacing (SCS) (μ PDSCH μ PDCCH The scheduling offset (K0) value 1010 of the data channel and control channel configured by the higher layer is used to indicate the time domain location of the PDSCH resource, and the start position 1000 and length 1005 of the OFDM symbol in a time slot are dynamically indicated by DCI.

[0232] PUCCH: Related to transmission

[0233] In an NR system, a UE can send control information (UCI) to a base station via PUCCH. The control information may include at least one of the following: a HARQ-ACK indicating whether the demodulation / decoding of a transport block (TB) received by the UE via PDSCH was successful; a scheduling request (SR) for the UE to request resource allocation from the PUSCH base station for uplink data transmission; or channel state information (CSI) as information for the UE's channel state reporting.

[0234] Based on the length of the allocated symbols, PUCCH resources can be mainly classified into long PUCCH and short PUCCH. In NR systems, long PUCCH has a length of 4 symbols or more in a time slot, while short PUCCH has a length of 2 symbols or less in a time slot.

[0235] To further describe the long PUCCH, it can be used to improve uplink cell coverage and therefore can be transmitted in a DFT-S-OFDM scheme as a single-carrier transmission rather than an OFDM transmission. The long PUCCH supports transmission formats such as PUCCH Format 1, PUCCH Format 3, and PUCCH Format 4, depending on the number of control information bits supported and whether UE multiplexing supported by Pre-DFT Orthogonal Covering Code (OCC) at a previous stage of the IFFT is supported.

[0236] PUCCH Format 1 is a long PUCCH format based on DFT-S-OFDM that supports up to 2 bits of control information and uses one RB frequency resource. The control information can consist of each of HARQ-ACK and SR, or a combination thereof. In PUCCH Format 1, OFDM symbols including the demodulation reference signal (DMRS) as a demodulation reference signal (or reference signal) and OFDM symbols including UCI are constructed in a repetitive manner.

[0237] For example, in the case where the number of transmission symbols in PUCCH format 1 is 8, starting from the first start symbol among the 8 symbols, PUCCH format 1 can be constructed in the following order: DMRS symbol, UCI symbol, DMRS symbol, UCI symbol, DMRS symbol, UCI symbol, DMRS symbol, and UCI symbol. Orthogonal codes (or orthogonal sequences or extended codes) in the time domain are used. i (m)), DMRS symbols can be extended to a sequence corresponding to the length of 1 RB in the frequency domain within an OFDM symbol, and can be transmitted after performing an IFFT.

[0238] For UCI symbols, the UE can generate d(0) by modulating 1-bit control information with BPSK and 2-bit control information with Quadrature Phase Shift Keying (QPSK). The generated d(0) is then multiplied by a sequence corresponding to the length of one RB in the frequency domain to perform scrambling, using an orthogonal code (or orthogonal sequence or spreading code, w) in the time domain. i (m) is used to perform expansion on the scrambled sequence, perform IFFT, and then perform transfer.

[0239] The UE can generate a sequence based on the configured ID and the group frequency hopping or sequence frequency hopping configuration received from the base station via higher-layer signaling, and generate a sequence corresponding to the length of 1 RB by cyclically shifting the generated sequence, wherein the initial cyclic shift (CS) value is configured via higher-layer signals.

[0240] If the length of the extension code (NSF) is given, then exist The details are shown in Table 20 below, where i indicates the index of the spreading code itself, and m indicates the index of the spreading code element. Here, the numbers in [ ] in Table 20 refer to... Furthermore, given that the length of the extension code is 2 and the index of the configured extension code is i=0, the extension code w i (m) becomes , , making w i (m) = [1 1].

[0241] [Table 20]

[0242] Next, PUCCH format 3 is a long PUCCH format based on DFT-S-OFDM that supports more than 2 bits of control information, and the number of RBs used can be configured through higher layers. The control information may include each of HARQ-ACK, SR, and CSI, or a combination thereof. In PUCCH format 3, the DMRS symbol positions are shown in Table 21 below, depending on whether additional DMRS symbols are configured and whether frequency hopping is configured within the time slot.

[0243] [Table 21]

[0244] In PUCCH format 3, where the number of transmission symbols is 8, DMRS is transmitted starting from the first start symbol (which is 0) and proceeding through the first and fifth symbols. Table 21 is applied in the same manner as the DMRS symbol positions in PUCCH format 4.

[0245] Next, PUCCH format 4 is a long PUCCH format based on DFT-S-OFDM that supports more than 2 bits of control information and uses one RB frequency resource. The control information can consist of each of HARQ-ACK, SR, and CSI, or a combination thereof. The difference between PUCCH format 4 and PUCCH format 3 is that, for PUCCH format 4, multiple UEs' PUCCH format 4 can be multiplexed within one RB. Multiplexing of multiple UEs' PUCCH format 4 can be achieved by applying Pre-DFT Orthogonal Cover Codes (OCCs) to the control information at a stage prior to the IFFT. However, the number of control information symbols that a UE can transmit decreases depending on the number of multiplexed UEs. The number of multiplexable UEs (i.e., the number of different available OCCs) can be 2 or 4, and the number of OCCs and the index of the OCCs to be applied can be configured through higher layers.

[0246] Next, the short PUCCH will be described. The short PUCCH can be transmitted in both the downlink center time slot and the uplink center time slot, and generally, it can be transmitted at the last symbol or the last OFDM symbol of the time slot (e.g., the last OFDM symbol, the penultimate OFDM symbol, or the last two OFDM symbols). Obviously, the short PUCCH can also be transmitted at random locations within the time slot. Furthermore, it can be transmitted using one or two OFDM symbols. The short PUCCH can be used to reduce latency compared to the long PUCCH when uplink cell coverage is good, and it can be transmitted using the CP-OFDM scheme.

[0247] Short PUCCHs can support transmission formats such as PUCCH Format 0 and PUCCH Format 2, depending on the number of bits of control information they can support. First, PUCCH Format 0 is a short PUCCH format capable of supporting up to 2 bits of control information and using one RB of frequency resources. The control information can consist of each of HARQ-ACK and SR, or a combination thereof. PUCCH Format 0 has a structure that does not transmit DMRS and only transmits a sequence mapped to 12 subcarriers in the frequency domain within one OFDM symbol. The UE can generate a sequence based on the configured ID and group frequency hopping or sequence frequency hopping configured by the base station via higher-layer signals. The generated sequence is then cyclically shifted using a final CS value obtained by adding different CS values ​​according to ACK or NACK to an indicated initial cyclic shift (CS) value, and the cyclically shifted sequence is mapped to 12 subcarriers for transmission.

[0248] For example, for a 1-bit HARQ-ACK, as shown in Table 22 below, if it is ACK, the UE can generate the final CS by adding 6 to the initial CS value, and if it is NACK, the UE can generate the final CS by adding 0 to the initial CS. The standard defines the CS value of NACK as 0 and the CS value of ACK as 6, and the UE can generate PUCCH format 0 to transmit a 1-bit HARQ-ACK according to the values ​​defined in the standard.

[0249] [Table 22]

[0250] For example, when HARQ-ACK is 2 bits, as shown in Table 23 below, for (NACK, NACK), the UE adds 0 to the initial CS value; for (NACK, ACK), it adds 3; for (ACK, ACK), it adds 6; and for (ACK, NACK), it adds 9. The standard defines a CS value of 0 for (NACK, NACK), 3 for (NACK, ACK), 6 for (ACK, ACK), and 9 for (ACK, NACK). The UE can generate PUCCH format 0 to transmit a 2-bit HARQ-ACK based on the values ​​defined in the standard. If the final CS value exceeds 12 due to adding the CS value to the initial CS value based on ACK or NACK, since the sequence length is 12, a modulo 12 can be applied to the final CS value.

[0251] [Table 23]

[0252] Next, PUCCH format 2 is a short PUCCH format that supports more than 2 bits of control information, and the number of RBs used can be configured by higher layers. The control information can consist of each of HARQ-ACK, SR, and CSI, or a combination thereof. In PUCCH format 2, when the index of the first subcarrier is #0, the position of the subcarrier transmitting DMRS can be fixed within an OFDM symbol to subcarriers with indices #1, #4, #7, and #10. The control information can be mapped to the remaining subcarriers after channel coding and modulation, excluding the subcarrier containing the DMRS.

[0253] In summary, the configurable values ​​and their ranges for the various PUCCH formats described above can be organized as shown in Table 24. When no value needs to be configured, it is represented as NA.

[0254] [Table 24]

[0255] To improve uplink coverage, PUCCH formats 1, 3, and 4 support multi-slot repetition, and PUCCH repetition can be configured for each PUCCH format. The UE can retransmit PUCCHs including UCIs as many times as the number of slots configured via nrofSlots as higher-layer signaling. For repetitive PUCCH transmissions, the same number of consecutive symbols can be used in each slot, and the number of consecutive symbols can be configured via nrofSymbols as higher-layer signaling in PUCCH-format 1, PUCCH-format 3, or PUCCH-format 4. The same start symbol can also be used in each slot, and the start symbol can be configured via startingSymbolIndex as higher-layer signaling in PUCCH-format 1, PUCCH-format 3, or PUCCH-format 4. A single PUCCH-spatialRelationInfo can be configured for each PUCCH resource for repetitive PUCCH transmissions. For repeated PUCCH transmissions, if the UE is configured to perform frequency hopping in different time slots during PUCCH transmissions, the UE can perform frequency hopping on a time slot basis. Furthermore, if the UE is configured to perform frequency hopping in different time slots during PUCCH transmissions, the UE can start PUCCH transmissions in even-numbered time slots from a first PRB index configured via the starting PRB as higher-layer signaling, and the UE can start PUCCH transmissions in odd-numbered time slots from a second PRB index configured via the second Hop PRB as higher-layer signaling. Additionally, if the UE is configured to perform frequency hopping in different time slots during PUCCH transmissions, the index of the time slot indicated to the UE for the first PUCCH transmission is 0, and during the configured total number of repeated PUCCH transmissions, the number of repeated PUCCH transmissions can be incremented in each time slot, regardless of the execution of the PUCCH transmissions. If the UE is configured to perform frequency hopping in different time slots during PUCCH transmissions, the UE does not expect to be configured to perform frequency hopping within a time slot during PUCCH transmissions. If the UE is not configured to perform frequency hopping in different time slots during PUCCH transmission, but is instead configured to perform frequency hopping within a time slot, then the first PRB index and the second PRB index are applied equally within that time slot. If the number of UL symbols available for PUCCH transmission is less than the nrofSymbols configured via higher-layer signaling, the UE may not transmit the PUCCH. Even if the UE fails to transmit the PUCCH in a specific time slot during repeated PUCCH transmissions, the UE may increase the number of repeated PUCCH transmissions.

[0256] In NR Release 17, the number of time slots for repeated transmission of each PUCCH resource can be configured via the higher-layer signaling pucch-RepetitionNrofSlots-r17 in PUCCH-ResourceExt. PUCCH-Resource is an extension of PUCCH-Resource, which is the higher-layer signaling for PUCCH resources. When the corresponding higher-layer signaling pucch-RepetitionNrofSlots-r17 is configured, the corresponding PUCCH resource is scheduled, and the higher-layer signaling nrofSlots is also configured, the UE determines the number of time slots for repeated transmission of the corresponding PUCCH resource through pucch-RepetitionNrofSlots-r17 and ignores the higher-layer signaling nrofSlots.

[0257] PUSCH: Related to transmission scheme

[0258] Next, the scheduling scheme for PUSCH transmissions will be described. PUSCH transmissions can be dynamically scheduled via UL authorization in the DCI, or they can be operated via configured authorization type 1 or type 2. Dynamic scheduling instructions for PUSCH transmissions can be implemented through DCI format 0_0 or 0_1.

[0259] For configured authorization type 1 PUSCH transports, UL authorization in the DCI may not be received, and configuration can be performed semi-statically by receiving configuredGrantConfig, which includes rrc-ConfiguredUplinkGrant as shown in Table 25, via higher-layer signaling. After receiving configuredGrantConfig, which does not include rrc-ConfiguredUplinkGrant as shown in Table 25, via higher-layer signaling, configured authorization type 2 PUSCH transports can be semi-persistently scheduled via UL authorization in the DCI. When operating PUSCH transports with configured authorization, the parameters applied to the PUSCH transports are applied via configuredGrantConfig as higher-layer signaling as shown in Table 25 below, except for scaling of dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and UCI-OnPUSCH provided via pusch-Config as higher-layer signaling as shown in Table 26. If the transformPrecoder is provided to the UE in the configuredGrantConfig, which is the higher-layer signaling in Table 25, the UE transmits tp-pi2BPSK in pusch-Config in Table 26 to the PUSCH that is configured for authorized operation.

[0260] [Table 25]

[0261] Next, the PUSCH transmission method will be described. The DRMS ​​antenna port used for PUSCH transmission is the same as the antenna port used for SRS transmission. PUSCH transmission can comply with either a codebook-based transmission method or a non-codebook-based transmission method, depending on whether the value of txConfig in pusch-Config as higher-layer signaling in Table 26 corresponds to "codebook" or "non-codebook".

[0262] As described above, PUSCH transmissions can be dynamically scheduled via DCI format 0_0 or 0_1, and can be semi-statically configured via configured authorization. If the UE is instructed to schedule a PUSCH transmission via DCI format 0_0, the UE performs beam configuration for the PUSCH transmission using the pucch-spatialRelationInfoID corresponding to the UE-specific PUCCH resource corresponding to the smallest ID within the uplink BWP active in the serving cell. In this case, the PUSCH transmission is based on a single antenna port. Within a BWP where no PUCCH resource including pucch-spatialRelationInfo is configured, the UE does not expect to schedule PUSCH transmissions via DCI format 0_0. If the UE is not configured with txConfig in pusch-Config of Table 26, the UE does not expect to schedule via DCI format 0_1.

[0263] [Table 26]

[0264] Next, codebook-based PUSCH transmission will be described. Codebook-based PUSCH transmission can be dynamically scheduled using DCI format 0_0 or 0_1, and can be operated semi-statically using configured grants. If codebook-based PUSCH is dynamically scheduled using DCI format 0_1 ​​or semi-statically configured using configured grants, the UE determines the precoder used for PUSCH transmission based on the SRS Resource Indicator (SRI), the Transport Precoding Matrix Indicator (TPMI), and the transport rank (the number of PUSCH transport layers).

[0265] In this scenario, the SRI can be provided to the UE via the SRS Resource Indicator field in the DCI, or configured via the srs-ResourceIndicator as higher-layer signaling. During codebook-based PUSCH transmission, the UE can be configured with at least one SRS resource and up to two SRS resources. When providing the SRI to the UE via the DCI, for the SRS resource indicated by the corresponding SRI, the SRS resource corresponding to the SRI can be referenced from the SRS resources transmitted before the PDCCH including the corresponding SRI. Additionally, the TPMI and transport rank can be given via the precoding information and layer number fields in the DCI, or configured via precodingAndNumberOfLayers as higher-layer 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 indicates the precoder to be applied to the configured SRS resource. If the UE is configured with multiple SRS resources, the TPMI indicates the precoder to be applied to the SRS resource indicated by the SRI.

[0266] The precoder to be used for PUSCH transmission is selected from the UL codebook, which has the same number of antenna ports as the value of nrofSRS-Ports in the SRS-Config (which is higher-layer signaling). In codebook-based PUSCH transmission, the UE determines the codebook subset based on the codebookSubset and TPMI in the push-Config (which is higher-layer signaling). Based on the UE capabilities reported by the UE to the base station, the codebookSubset in the push-Config (which is higher-layer signaling) can be configured as one of "fullyAndPartialAndNonCoherent", "partialAndNonCoherent", or "nonCoherent". If the UE has already reported "partialAndNonCoherent" as a UE capability, the UE does not expect the value of codebookSubset as higher-layer signaling to be configured as "fullyAndPartialAndNonCoherent". Conversely, if the UE has already reported "nonCoherent" as a UE capability, the UE does not expect the value of codebookSubset as higher-layer signaling to be configured as "fullAndPartialAndNonCoherent" or "partialAndNonCoherent". When nrofSRS-Ports in SRS-ResourceSet, which is used as higher-layer signaling, indicates two SRS antenna ports, the UE does not expect the value of codebookSubset, which is used as higher-layer signaling, to be configured as "partialAndNonCoherent".

[0267] A UE can be configured with an SRS resource set, where the usage value in the SRS-ResourceSet (for higher-layer signaling) is configured as a "codebook," and an SRS resource in the corresponding SRS resource set can be indicated via an SRI. If multiple SRS resources are configured in the SRS resource set, and the usage value in the SRS-ResourceSet (for higher-layer signaling) is configured as a "codebook," the UE expects the value of nrofSRS-Ports in the SRS-Resource (for higher-layer signaling) to be configured the same for all SRS resources.

[0268] The UE sends one or more SRS resources, whose usage values ​​are configured as a "codebook," to the base station according to higher-layer signaling. The base station selects one of the SRS resources to be transmitted by the UE and instructs the UE to perform PUSCH transmission using the transmission beam information of the corresponding SRS resource. In this codebook-based PUSCH transmission, the SRI is used as an index for selecting an SRS resource and is included in the DCI. Furthermore, the base station includes information in the DCI indicating the rank and TPMI to be used for the UE's PUSCH transmission. By applying a precoder indicated by the TPMI and rank (which are already based on the transmission beam indication of the corresponding SRS resource), the UE performs PUSCH transmission using the SRS resource indicated by the SRI.

[0269] Next, non-codebook-based PUSCH transmission will be described. Non-codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can be operated semi-statically via configured authorization. When at least one SRS resource is configured in an SRS resource set where the usage value in the SRS-ResourceSet (as higher-layer signaling) is configured as "non-codebook," the UE can be scheduled for non-codebook-based PUSCH transmission via DCI format 0_1.

[0270] For an SRS resource set whose usage value in the higher-layer signaling SRS-ResourceSet is configured as "non-codebook", the UE can be configured with an associated non-zero power (NZP) CSI-RS resource. By measuring the NZP CSI-RS resource associated with the SRS resource set, the UE can perform calculations for the precoder used for SRS transmission. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource associated with the SRS resource set and the first symbol of the aperiodic SRS transmission in the UE is less than 42 symbols, the UE does not expect to update information related to the precoder used for SRS transmission.

[0271] If the resourceType value in the SRS-ResourceSet used for higher-layer signaling is configured as "aperiodic," the associated NZP CSI-RS can be indicated by the SRS request field in DCI format 0_1 ​​or 1_1. In this case, if the associated NZP CSI-RS resource is aperiodic, the presence of the associated NZP CSI-RS is indicated when the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not "00." In this case, the corresponding DCI should not indicate cross-carrier or cross-BWP scheduling. Furthermore, if the SRS request value indicates the presence of an NZP CSI-RS, the corresponding NZP CSI-RS is located in the time slot where a PDCCH including the SRS request field has already been transmitted. In this case, the TCI state configured in the scheduled subcarrier is not configured as QCL-TypeD.

[0272] If a periodic or semi-persistent SRS resource set is configured, the associated NZP CSI-RS can be indicated by the associated CSI-RS in the SRS-ResourceSet as higher-layer signaling. For non-codebook-based transmissions, the UE does not expect spatialRelationInfo as higher-layer signaling for SRS resources and associated CSI-RS in the SRS-ResourceSet as higher-layer signaling to be configured together.

[0273] 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. In this case, the SRI can be indicated by the SRS resource indicator field in the DCI, or configured by the srs-ResourceIndicator as higher-layer signaling. Similar to the codebook-based PUSCH transmission described above, when the SRI is provided to the UE via the DCI, the SRS resource indicated by the corresponding SRI refers to the SRS resource corresponding to the SRI among those transmitted before the PDCCH including the corresponding SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be transmitted simultaneously in the same symbol within an SRS resource set can be determined by the UE capability reported by the UE to the base station. In this case, the SRS resources transmitted simultaneously by the UE occupy the same RB. The UE configures one SRS port for each SRS resource. It is possible to configure only one SRS resource set in which the usage value in the SRS-ResourceSet used for higher-layer signaling is configured as "non-codebook", and up to four SRS resources can be configured for non-codebook-based PUSCH transmissions.

[0274] The base station sends an NZP CSI-RS associated with an SRS resource set to the UE, and the UE calculates the precoder to be used during the transmission of one or more SRS resources in the corresponding SRS resource set based on measurements taken during the reception of the NZP CSI-RS. When sending one or more SRS resources in an SRS resource set whose usage is configured as "non-codebook" to the base station, the UE applies the calculated precoder, and the base station can select one or more SRS resources from the received SRS resources. In this case, in non-codebook-based PUSCH transmission, the SRI indicates an index that can represent one SRS resource or a combination of multiple SRS resources, and the SRI can be included in the DCI. In this case, the number of SRS resources indicated by the SRI sent by the base station can be the number of PUSCH transport layers, and the UE can transmit PUSCH by applying the precoder used for SRS resource transmission to each layer.

[0275] Related to SRS

[0276] Next, an uplink channel estimation method using the UE's Sounding Reference Signal (SRS) transmission will be described. The base station can configure at least one SRS configuration for each uplink BWP to transmit configuration information for SRS transmission to the UE, and at least one SRS resource set can be configured for each SRS configuration. For example, the base station and UE can transmit and receive the following higher-layer signaling information to transmit information about the SRS resource set.

[0277] -srs-ResourceSetId: Index of the SRS resource set

[0278] -srs-ResourceIdList: Index of SRS resources referenced in the SRS resource set.

[0279] -resourceType: The time-domain transmission configuration of the SRS resources referenced in the SRS resource set. It can be configured as "periodic," "semi-persistent," or "aperiodic." When configured as "periodic" or "semi-persistent," associated CSI-RS information can be provided depending on the purpose of the SRS resource set. When configured as "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 purpose of the SRS resource set.

[0280] - Purpose: Configures the purpose of SRS resources referenced in the SRS resource set, which can be configured as one of "beam management", "codebook", "non-codebook" and "antenna switching".

[0281] -alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter configurations for adjusting the transmission power of SRS resources referenced in the SRS resource set.

[0282] The UE can understand that the SRS resources included in the SRS resource index referenced in the SRS resource set follow the information configured in the SRS resource set.

[0283] Additionally, the base station and UE can transmit and receive higher-layer signaling information to convey individual configuration information for SRS resources. For example, the individual configuration information for SRS resources may include time-frequency domain mapping information within the time slots of the SRS resources, and this time-frequency domain mapping information may include information related to frequency hopping between or within time slots of the SRS resources. Furthermore, the individual configuration information for SRS resources may include the time-domain transmission configuration of the SRS resources, and may be configured as "periodic," "semi-persistent," and "aperiodic." This can be limited to having the same time-domain transmission configuration as the set of SRS resources that includes the SRS resources. When the time-domain transmission configuration of the SRS resources is configured as "periodic" or "semi-persistent," the transmission period and time slot offset (e.g., periodicityAndOffset) of the SRS resources may be additionally included in the time-domain transmission configuration.

[0284] The base station can activate, deactivate, or trigger SRS transmissions to the UE via higher-layer signaling, including RRC signaling, MAC CE signaling, or L1 signaling (e.g., DCI). For example, the base station can activate or deactivate periodic SRS transmissions to the UE via higher-layer signaling. The base station can instruct the activation of an SRS resource set where the resourceType is configured as periodic, and the UE can transmit SRS resources referenced in the activated SRS resource set. The time-frequency domain resource mapping in the time slots of the transmitted SRS resources follows the resource mapping information configured in the SRS resources, and the time slot mapping, including the transmission period and time slot offset, follows the periodicityAndOffset configured in the SRS resources. Furthermore, the spatial domain transmission filter applied to the transmitted SRS resources can refer to spatial relationship information configured in the SRS resources, or it can refer to associated CSI-RS information configured in the SRS resource set including the SRS resources. The UE can transmit SRS resources in the activated uplink BWP used for periodic SRS resources activated via higher-layer signaling.

[0285] For example, a base station can activate or deactivate semi-persistent SRS transmission to a UE via higher-layer signaling. The base station can instruct the activation of an SRS resource set via MAC CE signaling, and the UE can transmit SRS resources referenced in the activated SRS resource set. The SRS resource set activated via MAC CE signaling can be limited to those where the resource type is configured as semi-persistent. The time-frequency domain resource mapping in the time slots of the transmitted SRS resources follows the resource mapping information configured in the SRS resources, and the time slot mapping, including the transmission period and time slot offset, follows the periodicityAndOffset configured in the SRS resources. Furthermore, the spatial domain transmission filter applied to the transmitted SRS resources can refer to spatial relation information configured in the SRS resources, or it can refer to associated CSI-RS information configured in the SRS resource set including the SRS resources. If the spatial relation information is configured in the SRS resources, the spatial relation information may not be followed, and the spatial domain transmission filter can be determined by referring to the configuration information of the spatial relation information transmitted by the MAC CE signaling used to activate the semi-persistent SRS transmission. The UE can transmit SRS resources in the activated uplink BWP used for semi-persistent SRS resources activated via higher-layer signaling.

[0286] For example, a base station can trigger aperiodic SRS transmissions to the UE via DCI. The base station can indicate one of the aperiodic SRS resource triggers (aperiodicSRS-ResourceTriggers) through the SRS request field of the DCI. The UE understands that the SRS resource set including the aperiodic SRS resource trigger indicated by the DCI is triggered in the aperiodic SRS resource trigger list in the SRS resource set configuration information. The UE can transmit SRS resources referenced in the triggered SRS resource set. The time-frequency domain resource mapping in the time slots of the transmitted SRS resources follows the resource mapping information configured in the SRS resources. Furthermore, the time slot mapping of the transmitted SRS resources can be determined by the time slot offset between the PDCCH including the DCI and the SRS resources, and this time slot offset can refer to values ​​included in the time slot offset set configured in the SRS resource set. More specifically, the time slot offset between the PDCCH including the DCI and the SRS resources can be applied to the value indicated in the time domain resource allocation field of the DCI, which is among the offset values ​​included in the time slot offset set configured in the SRS resource set. Furthermore, the spatial domain transmission filter applied to the transmitted SRS resources can refer to spatial relationship information configured in the SRS resources, or it can refer to associated CSI-RS information configured in an SRS resource set that includes the SRS resources. The UE can transmit SRS resources in an activated uplink BWP for aperiodic SRS resources triggered by DCI.

[0287] When a base station triggers aperiodic SRS transmissions to the UE via DCI, in order to transmit SRS using the configuration information of applied SRS resources, the UE may require a minimum time interval between the PDCCH of the DCI that triggers the aperiodic SRS transmission and the transmitted SRS. The time interval for SRS transmission to the UE can be defined as the number of symbols between the last symbol of the PDCCH of the DCI that triggers the aperiodic SRS transmission and the first symbol mapped to the earliest transmitted SRS resource among the transmitted SRS resources. The minimum time interval can be determined by referring to the PUSCH preparation process time required for the UE to prepare for PUSCH transmission. Furthermore, the minimum time interval can vary depending on the purpose of the SRS resource set including the transmitted SRS resources. For example, the minimum time interval can be determined as N² symbols defined based on the UE's processing capabilities, taking into account the UE's PUSCH preparation process time. Furthermore, when the purpose of the SRS resource set is configured as "codebook" or "antenna switching" by considering the intended use of the SRS resource set including the transmitted SRS resources, the minimum time interval can be determined to be N² symbols. When the purpose of the SRS resource set is configured as "non-codebook" or "beam management," the minimum time interval can be determined to be N²+14 symbols. When the time interval used for SRS transmission is equal to or greater than the minimum time interval, the UE can transmit aperiodic SRS. When the time interval used for SRS transmission is less than the minimum time interval, the UE can ignore the DCI used to trigger aperiodic SRS.

[0288] [Table 27]

[0289] Referring to a reference signal, the spatialRelationInfo configuration information in Table 27 above applies the beam information of the corresponding reference signal to the beam used for the corresponding SRS transmission. For example, the spatialRelationInfo configuration may include the information in Table 28.

[0290] [Table 28]

[0291] Referring to the spatialRelationInfo configuration, in order to use the beam information of a specific reference signal, the base station can configure the SS / PBCH block index, CSI-RS index, or SRS index to be referenced as the index of the reference signal to be referenced. In turn, the higher-layer signaling reference signal is configuration information indicating which reference signal beam information to reference for the corresponding SRS transmission. The ssb-index refers to the SS / PBCH block index, the csi-RS-index refers to the CSI-RS index, and the srs refers to the SRS index. If the value of the higher-layer signaling reference signal is configured as "ssb-Index", the UE can apply the receive beam used when receiving the SS / PBCH block corresponding to the ssb-Index as the transmission beam for the corresponding SRS transmission. If the value of the higher-layer signaling reference signal is configured as "csi-RS-Index", the UE can apply the receive beam used when receiving the CSI-RS corresponding to the csi-RS-Index as the transmission beam for the corresponding SRS transmission. If the value of the higher-layer signaling referenceSignal is configured as "srs", the UE can use the transmission beam used when transmitting the SRS corresponding to the srs as the transmission beam for transmitting the corresponding SRS.

[0292] SRS: Antenna Switching

[0293] The SRS used for antenna switching will be described below.

[0294] The base station can use SRS transmitted from the UE to acquire DL channel state information (CSI) (e.g., DL CSI acquisition). As a specific example, in a time-division duplex (TDD) based single-cell or multi-cell (e.g., carrier aggregation (CA)) scenario, the base station (BS) can schedule SRS transmissions to the user equipment (UE) and then measure the SRS transmitted from the UE. In this case, by assuming reciprocity between the downlink (DL) and uplink (UL) channels, the base station can consider the uplink channel information estimated based on the SRS transmitted from the UE as downlink channel information and can use this information to schedule downlink signals / channels for the UE. In this scenario, the base station can configure the use of the SRS for downlink channel information acquisition for antenna switching for the UE.

[0295] As an example, according to specifications (e.g., 3GPP TS38.214), the purpose of SRS can be configured for the base station and / or UE using higher-layer parameters (e.g., the purpose of the RRC parameter SRS-ResourceSet). Here, the purpose of SRS can be configured for beam management, codebook transmission, non-codebook transmission, antenna switching, etc.

[0296] As previously mentioned, when the base station configures the parameters in the higher-layer signaling SRS-ResourceSet for "antennaSwitching" for the UE, the UE can receive at least one higher-layer signaling configuration from the base station based on the reported UE capabilities. In this case, the UE can report "supportedSRS-TxPortSwitch" as a UE capability, and its value can be as follows. In the following text, "mTnR" can represent a UE capability that supports transmission through m antennas and reception through n antennas.

[0297] “t1r2”: UE capability report value, indicating that the UE supports 1T2R operation.

[0298] “t1r1-t1r2”: UE capability report value, indicating that the UE supports 1T1R or 1T2R operation.

[0299] “t2r4”: UE capability report value, indicating that the UE supports 2T4R operation.

[0300] “t1r4”: UE capability report value, indicating that the UE supports 1T4R operation.

[0301] “t1r6”: UE capability report value, indicating that the UE supports 1T6R operation.

[0302] “t1r8”: UE capability report value, indicating that the UE supports 1T8R operation.

[0303] “t2r6”: UE capability report value, indicating that the UE supports 2T6R operation.

[0304] “t2r8”: UE capability report value, indicating that the UE supports 2T8R operation.

[0305] “t4r8”: UE capability report value, indicating that the UE supports 4T8R operation.

[0306] “t1r1-t1r2-t1r4”: UE capability report value, indicating that the UE supports 1T1R, 1T2R or 1T4R operation.

[0307] “t1r4-t2r4”: UE capability report value, indicating that the UE supports 1T4R or 2T4R operation.

[0308] “t1r1-t1r2-t2r2-t2r4”: UE capability report value, indicating that the UE supports 1T1R, 1T2R, 2T2R or 2T4R operation.

[0309] “t1r1-t1r2-t2r2-t1r4-t2r4”: UE capability report value, indicating that the UE supports 1T1R, 1T2R, 2T2R, 1T4R or 2T4R operation.

[0310] “t1r1”: UE capability report value, indicating that the UE supports 1T1R operation.

[0311] “t2r2”: UE capability report value, indicating that the UE supports 2T2R operation.

[0312] “t1r1-t2r2”: UE capability report value, indicating that the UE supports 1T1R or 2T2R operation.

[0313] “t4r4”: UE capability report value, indicating that the UE supports 4T4R operation.

[0314] “t1r1-t2r2-t4r4”: UE capability report value, indicating that the UE supports 1T1R, 2T2R or 4T4R operation.

[0315] [1T2R]

[0316] Regarding UE 1T2R operations, higher-layer signaling related to a combination of base station configuration and at least one of the following details can be used to perform operations.

[0317] If the UE reports part or all of srs-AntennaSwitching2SP-1Periodic-r17 and srs-ExtensionAperiodicSRS-r17 (which are UE capability reports), In the case where the UE only reported srs-AntennaSwitching2SP-1Periodic-r17 The base station can configure up to two SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling, and the base station can configure up to one SRS resource set with a resource type value of "periodic" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling, or The base station can configure up to two SRS resource sets with different resource type values ​​for the UE in the SRS-ResourceSet, which serves as higher-layer signaling.

[0318] Regarding the above details, two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling, can not be activated simultaneously.

[0319] Regarding the details above, each SRS resource set may include two SRS resources transmitted in different OFDM symbols.

[0320] Regarding the above details, each SRS resource in each SRS resource set can consist of one SRS port, and the SRS ports of the corresponding SRS resources in each SRS resource set can be connected to different UE antenna ports.

[0321] As an example, first and second SRS resources (each consisting of one SRS port) can be included in a corresponding SRS resource set. The corresponding SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The SRS port of the first SRS resource can transmit at the first OFDM symbol location, and the SRS port of the second SRS resource can transmit at the second OFDM symbol location. In this case, the first and second OFDM symbol locations are different from each other, but the time slot locations can be the same or different from each other.

[0322] In the case where the UE only reports srs-ExtensionAperiodicSRS-r17 The base station can configure up to two SRS resource sets with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling, and the base station can configure up to one SRS resource set with a resource type value of "periodic" or "semi-persistent" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling. The base station can configure up to two SRS resource sets with different resource type values ​​for the UE in the SRS-ResourceSet, which serves as higher-layer signaling.

[0323] Regarding the above details, when the base station configures two SRS resource sets with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet as higher-layer signaling, the corresponding SRS resources in these two SRS resource sets can be transmitted at the same or different OFDM symbol locations in two different time slots. Each SRS resource set can include one SRS resource, each SRS resource in the two SRS resource sets can be composed of one SRS port, and the SRS ports of the corresponding SRS resources in the two SRS resource sets can be connected to different UE antenna ports.

[0324] As an example, a first SRS resource consisting of one SRS port may be included in a first SRS resource set, and a second SRS resource consisting of one SRS port may be included in a second SRS resource set. The corresponding SRS ports of the first and second SRS resources may be connected to different UE antenna ports. The SRS port of the first SRS resource may be transmitted at the first OFDM symbol location in a first time slot, and the SRS port of the second SRS resource may be transmitted at the second OFDM symbol location in a second time slot. In this case, the first and second OFDM symbol locations in each time slot may be the same or different from each other, but the time slot locations may be different from each other.

[0325] Regarding the above details, when the base station configures an SRS resource set with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet which serves as higher-layer signaling, two SRS resources in the corresponding SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. Each SRS resource in the corresponding SRS resource set can be composed of an SRS port, and the SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0326] As an example, the first and second SRS resources (each consisting of one SRS port) can be included in the corresponding SRS resource set, the corresponding SRS ports of the first and second SRS resources can be connected to different UE antenna ports, the SRS port of the first SRS resource can be transmitted at the first OFDM symbol position in the first time slot, and the SRS port of the second SRS resource can be transmitted at the second OFDM symbol position in the same time slot.

[0327] Regarding the above details, when the base station configures an SRS resource set with a resource type value of "periodic" or "semi-persistent" for the UE in the SRS-ResourceSet which serves as higher-layer signaling, the two SRS resources in the corresponding SRS resource set can be transmitted at different OFDM symbol locations, each SRS resource in the corresponding SRS resource set can be composed of an SRS port, and the SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0328] As an example, the first and second SRS resources (each consisting of one SRS port) can be included in the corresponding SRS resource set, the corresponding SRS ports of the first and second SRS resources can be connected to different UE antenna ports, the SRS port of the first SRS resource can be transmitted at the first OFDM symbol position in the first time slot, and the SRS port of the second SRS resource can be transmitted at the second OFDM symbol position in the same time slot.

[0329] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17, the base station can configure up to two (e.g., 0, 1, or 2) SRS resource sets for the UE in the SRS-ResourceSet, which is a higher-layer signaling layer, and each set has a resource type value of "periodic" or "semi-persistent" and is different from the others. As an example, the base station can configure one of the following details for the UE.

[0330] An SRS resource set with a resource type value of "periodic" or "semi-persistent" is not configured in the SRS-ResourceSet used for high-level signaling.

[0331] An SRS resource set with a resource type value of "periodic" in the SRS-ResourceSet, which serves as high-level signaling.

[0332] An SRS resource set with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling.

[0333] In the SRS-ResourceSet, which serves as high-level signaling, there is an SRS resource set with a resource type value of "periodic" and another SRS resource set within it with a resource type value of "semi-persistent".

[0334] Regarding the above details, two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling, can not be activated simultaneously.

[0335] Regarding the above details, each SRS resource set may include two SRS resources, which can be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set can be composed of one SRS port, and the SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0336] As an example, the first and second SRS resources (each consisting of one SRS port) can be included in the corresponding SRS resource set, the corresponding SRS ports of the first and second SRS resources can be connected to different UE antenna ports, the SRS port of the first SRS resource can be transmitted at the first OFDM symbol position in the first time slot, and the SRS port of the second SRS resource can be transmitted at the second OFDM symbol position in the same time slot.

[0337] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17, the base station can configure up to two SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as higher-layer signaling, and the base station can configure up to one SRS resource set with a resource type value of "periodic" for the UE in the SRS-ResourceSet as higher-layer signaling.

[0338] Regarding the above details, two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling, can not be activated simultaneously.

[0339] Regarding the above details, each SRS resource set may include two SRS resources, and the two corresponding SRS resources may be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set may consist of one SRS port, and the SRS port of the corresponding SRS resource may be connected to different UE antenna ports.

[0340] As an example, first and second SRS resources (each consisting of one SRS port) can be included in a corresponding SRS resource set. The corresponding SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The SRS port of the first SRS resource can transmit at the first OFDM symbol location, and the SRS port of the second SRS resource can transmit at the second OFDM symbol location. In this case, the first and second OFDM symbol locations are different from each other, but the time slot locations can be the same or different from each other.

[0341] If the UE has not reported srs-ExtensionAperiodicSRS-r17, the base station can configure at most one (e.g., 0 or 1) SRS resource set for the UE in the SRS-ResourceSet, which is a higher-layer signaling layer, with a resource type value of "aperiodic". As an example, the base station can configure one of the following details for the UE.

[0342] An SRS resource set with a resource type value of "non-periodic" is not configured in the SRS-ResourceSet, which serves as high-level signaling.

[0343] An SRS resource set with a resource type value of "aperiodic" in the SRS-ResourceSet, which serves as high-level signaling.

[0344] Regarding the above details, when an SRS resource set is configured, each SRS resource set can include two SRS resources. The two corresponding SRS resources can be transmitted at different OFDM symbol locations in the same time slot. Each SRS resource in the corresponding SRS resource set can be composed of an SRS port, and the SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0345] As an example, the first and second SRS resources (each consisting of one SRS port) can be included in the corresponding SRS resource set, the corresponding SRS ports of the first and second SRS resources can be connected to different UE antenna ports, the SRS port of the first SRS resource can be transmitted at the first OFDM symbol position in the first time slot, and the SRS port of the second SRS resource can be transmitted at the second OFDM symbol position in the same time slot.

[0346] When the UE only reports srs-ExtensionAperiodicSRS-r17, the base station can configure up to two (e.g., 0, 1, or 2) SRS resource sets for the UE in the SRS-ResourceSet, which is a higher-layer signaling, with a resource type value of "aperiodic". As an example, the base station can configure one of the following details for the UE.

[0347] An SRS resource set with a resource type value of "non-periodic" is not configured in the SRS-ResourceSet, which serves as high-level signaling.

[0348] An SRS resource set with a resource type value of "aperiodic" in the SRS-ResourceSet, which serves as high-level signaling.

[0349] In the SRS-ResourceSet, which serves as high-level signaling, there are two SRS resource sets with a resource type value of "aperiodic".

[0350] Regarding the above details, when an SRS resource set is configured, each SRS resource set can include two SRS resources. The two SRS resources can be transmitted at different OFDM symbol locations in the same time slot. Each SRS resource in the corresponding SRS resource set can include an SRS port, and the SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0351] As an example, the first and second SRS resources (each consisting of one SRS port) can be included in the corresponding SRS resource set, the corresponding SRS ports of the first and second SRS resources can be connected to different UE antenna ports, the SRS port of the first SRS resource can be transmitted at the first OFDM symbol position in the first time slot, and the SRS port of the second SRS resource can be transmitted at the second OFDM symbol position in the same time slot.

[0352] Regarding the above details, when two SRS resource sets are configured, the corresponding SRS resources in the two SRS resource sets can be transmitted at the same or different OFDM symbol locations in two different time slots. Each SRS resource set can include one SRS resource, and each SRS resource in the two SRS resource sets can be composed of one SRS port. Furthermore, the SRS ports of the corresponding SRS resources in the two SRS resource sets can be connected to different UE antenna ports.

[0353] As an example, a first SRS resource consisting of one SRS port may be included in a first SRS resource set, and a second SRS resource consisting of one SRS port may be included in a second SRS resource set. The corresponding ports of the first and second SRS resources may be connected to different UE antenna ports. The SRS port of the first SRS resource may be transmitted at the first OFDM symbol location in a first time slot, and the SRS port of the second SRS resource may be transmitted at the second OFDM symbol location in a second time slot. In this case, the first and second OFDM symbol locations in the corresponding time slots may be the same or different from each other, but the time slot locations may be different from each other.

[0354] In the case that the UE does not report both srs-AntennaSwitching2SP-1Periodic-r17 and srs-ExtensionAperiodicSRS-r17 (which are UE capability reports)

[0355] The base station can configure up to two SRS resource sets with different resource type values ​​for the UE in the SRS-ResourceSet, which serves as higher-layer signaling.

[0356] Regarding the above details, each SRS resource set may include two SRS resources, and the two corresponding SRS resources may be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set may consist of one SRS port, and the SRS port of the corresponding SRS resource may be connected to different UE antenna ports.

[0357] As an example, first and second SRS resources (each consisting of one SRS port) can be included in a corresponding SRS resource set. The corresponding SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The SRS port of the first SRS resource can transmit at the first OFDM symbol location, and the SRS port of the second SRS resource can transmit at the second OFDM symbol location. In this case, the first and second OFDM symbol locations can be different from each other, but the time slot locations can be the same or different from each other.

[0358] [2T4R]

[0359] Regarding the 2T4R operation of the UE, higher-layer signaling related to a combination of at least one of the following details from the base station can be configured, and operation can be performed based on this.

[0360] In the case where the UE reports part or all of the SRS-AntennaSwitching2SP-1Periodic-r17 and SRS-ExtensionAperiodicSRS-r17 (which are UE capability reports),

[0361] In the case where the UE only reported srs-AntennaSwitching2SP-1Periodic-r17

[0362] The base station can configure up to two SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling, and the base station can configure up to one SRS resource set with a resource type value of "periodic" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling, or

[0363] The base station can configure up to two SRS resource sets with different resource type values ​​for the UE in the SRS-ResourceSet, which serves as higher-layer signaling.

[0364] Regarding the above details, two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling, can not be activated simultaneously.

[0365] Regarding the details above, each SRS resource set may include two SRS resources transmitted in different OFDM symbols.

[0366] Regarding the above details, each SRS resource in each SRS resource set can consist of two SRS ports, and the two SRS ports of each SRS resource in each SRS resource set can be connected to different UE antenna ports.

[0367] As an example, first and second SRS resources (each consisting of one SRS port) can be included in the corresponding SRS resource set. The two SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The two SRS ports of the first SRS resource can transmit at the first OFDM symbol location, and the two SRS ports of the second SRS resource can transmit at the second OFDM symbol location. The first and second OFDM symbol locations can be different from each other in each time slot, but can have the same or different time slot locations.

[0368] In the case where the UE only reports srs-ExtensionAperiodicSRS-r17 The base station can configure up to two SRS resource sets with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling, and the base station can configure up to one SRS resource set with a resource type value of "periodic" or "semi-persistent" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling. The base station can configure up to two SRS resource sets with different resource type values ​​for the UE in the SRS-ResourceSet, which serves as higher-layer signaling.

[0369] Regarding the above details, when the base station configures two SRS resource sets with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet as higher-layer signaling, the corresponding SRS resources in these two SRS resource sets can be transmitted at the same or different OFDM symbol locations in two different time slots. Each SRS resource set can include one SRS resource, and the corresponding SRS resources in the two SRS resource sets can be composed of two SRS ports. Furthermore, the two SRS ports of the corresponding SRS resources in the two SRS resource sets can be connected to different UE antenna ports.

[0370] As an example, a first SRS resource consisting of two SRS ports may be included in a first SRS resource set, and a second SRS resource consisting of two SRS ports may be included in a second SRS resource set. The two SRS ports of the first and second SRS resources may be connected to different UE antenna ports. The two SRS ports of the first SRS resource may transmit at the first OFDM symbol location in a first time slot, and the two SRS ports of the second SRS resource may transmit at the second OFDM symbol location in a second time slot. In this case, the first and second OFDM symbol locations in each time slot may be the same or different from each other, but the time slot locations may be different from each other.

[0371] Regarding the above details, when the base station configures an SRS resource set with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet which serves as higher-layer signaling, the two SRS resources in the corresponding SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. Each SRS resource in the corresponding SRS resource set can be composed of two SRS ports, and the SRS ports of the corresponding SRS resources can be connected to different UE antenna ports.

[0372] Regarding the above details, when the base station configures an SRS resource set with a resource type value of "periodic" or "semi-persistent" for the UE in the SRS-ResourceSet which serves as higher-layer signaling, the two SRS resources in the corresponding SRS resource set can be transmitted at different OFDM symbol locations, each SRS resource in the corresponding SRS resource set can be composed of two SRS ports, and the two SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0373] As an example, first and second SRS resources (each consisting of two SRS ports) can be included in a corresponding SRS resource set. The two SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The two SRS ports of the first SRS resource can transmit at a first OFDM symbol location, and the two SRS ports of the second SRS resource can transmit at a second OFDM symbol location. In this case, the first and second OFDM symbol locations can be different from each other, but the time slot locations can be the same or different from each other.

[0374] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17, the base station can configure up to two (e.g., 0, 1, or 2) SRS resource sets for the UE in the SRS-ResourceSet, which is a higher-layer signaling layer, and each set has a resource type value of "periodic" or "semi-persistent" and is different from the others. As an example, the base station can configure one of the following details for the UE.

[0375] An SRS resource set with a resource type value of "periodic" or "semi-persistent" is not configured in the SRS-ResourceSet used for high-level signaling.

[0376] An SRS resource set with a resource type value of "periodic" in the SRS-ResourceSet, which is used as a high-level signaling layer.

[0377] An SRS resource set with a resource type value of "semi-persistent" in the SRS-ResourceSet, which is used as a high-level signaling layer.

[0378] In the SRS-ResourceSet, which serves as high-level signaling, there is an SRS resource set with a resource type value of "periodic" and another SRS resource set within it with a resource type value of "semi-persistent".

[0379] Regarding the above details, two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling, can not be activated simultaneously.

[0380] Regarding the above details, each SRS resource set may include two SRS resources, and the two corresponding SRS resources may be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set may consist of two SRS ports, and the two SRS ports of the corresponding SRS resource may be connected to different UE antenna ports.

[0381] As an example, first and second SRS resources (each consisting of two SRS ports) can be included in a corresponding SRS resource set. The two SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The two SRS ports of the first SRS resource can transmit at a first OFDM symbol location, and the two SRS ports of the second SRS resource can transmit at a second OFDM symbol location. In this case, the first and second OFDM symbol locations can be different from each other, but the time slot locations can be the same or different from each other.

[0382] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17, the base station can configure up to two SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as higher-layer signaling, and the base station can configure up to one SRS resource set with a resource type value of "periodic" for the UE in the SRS-ResourceSet as higher-layer signaling.

[0383] Regarding the above details, two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling, can not be activated simultaneously.

[0384] Regarding the above details, each SRS resource set may include two SRS resources, and the two corresponding SRS resources may be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set may consist of two SRS ports, and the two SRS ports of the corresponding SRS resource may be connected to different UE antenna ports.

[0385] As an example, first and second SRS resources (each consisting of two SRS ports) can be included in a corresponding SRS resource set. The two SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The two SRS ports of the first SRS resource can transmit at a first OFDM symbol location, and the two SRS ports of the second SRS resource can transmit at a second OFDM symbol location. In this case, the first and second OFDM symbol locations can be different from each other, but the time slot locations can be the same or different from each other.

[0386] If the UE does not report srs-ExtensionAperiodicSRS-r17, the base station can configure at most one (e.g., 0 or 1) SRS resource set for the UE in the SRS-ResourceSet, which is a higher-layer signaling layer, with a resource type value of "aperiodic". As an example, the base station can configure one of the following details for the UE.

[0387] An SRS resource set with a resource type value of "non-periodic" is not configured in the SRS-ResourceSet, which serves as high-level signaling.

[0388] An SRS resource set with a resource type value of "aperiodic" in the SRS-ResourceSet, which serves as high-level signaling.

[0389] Regarding the above details, when an SRS resource set is configured, each SRS resource set can include two SRS resources. The two corresponding SRS resources can be transmitted at different OFDM symbol locations in the same time slot. Each SRS resource in the corresponding SRS resource set can be composed of two SRS ports, and the two SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0390] As an example, the first and second SRS resources (each consisting of two SRS ports) can be included in the corresponding SRS resource set. The two SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The two SRS ports of the first SRS resource can be transmitted at the first OFDM symbol position in the first time slot, and the two SRS ports of the second SRS resource can be transmitted at the second OFDM symbol position in the same time slot.

[0391] When a UE reports srs-ExtensionAperiodicSRS-r17, the base station can configure up to two (e.g., 0, 1, or 2) SRS resource sets for the UE in the SRS-ResourceSet, which is a higher-layer signaling layer, with a resource type value of "aperiodic". As an example, the base station can configure one of the following details for the UE.

[0392] An SRS resource set with a resource type value of "non-periodic" is not configured in the SRS-ResourceSet, which serves as high-level signaling.

[0393] An SRS resource set with a resource type value of "aperiodic" in the SRS-ResourceSet, which serves as high-level signaling.

[0394] In the SRS-ResourceSet, which serves as high-level signaling, there are two SRS resource sets with a resource type value of "aperiodic".

[0395] Regarding the above details, when an SRS resource set is configured, each SRS resource set can include two SRS resources. The two corresponding SRS resources can be transmitted at different OFDM symbol locations in the same time slot. Each SRS resource in the corresponding SRS resource set can be composed of two SRS ports, and the two SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0396] As an example, the first and second SRS resources (each consisting of two SRS ports) can be included in the corresponding SRS resource set. The two SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The two SRS ports of the first SRS resource can be transmitted at the first OFDM symbol position in the first time slot, and the two SRS ports of the second SRS resource can be transmitted at the second OFDM symbol position in the same time slot.

[0397] Regarding the above details, when two SRS resource sets are configured, the corresponding SRS resources in these two SRS resource sets can be transmitted at the same or different OFDM symbol locations in two different time slots. Each SRS resource set can include one SRS resource, and the corresponding SRS resources in the two SRS resource sets can be composed of two SRS ports. Furthermore, the two SRS ports of the corresponding SRS resources in the two SRS resource sets can be connected to different UE antenna ports.

[0398] As an example, a first SRS resource consisting of two SRS ports may be included in a first SRS resource set, and a second SRS resource consisting of two SRS ports may be included in a second SRS resource set. The two SRS ports of the first and second SRS resources may be connected to different UE antenna ports. The two SRS ports of the first SRS resource may transmit at the first OFDM symbol location in a first time slot, and the two SRS ports of the second SRS resource may transmit at the second OFDM symbol location in a second time slot. In this case, the first and second OFDM symbol locations in the corresponding time slots may be the same or different from each other, but the time slot locations may be different from each other.

[0399] In the case that the UE does not report both srs-AntennaSwitching2SP-1Periodic-r17 and srs-ExtensionAperiodicSRS-r17 (which are UE capability reports)

[0400] The base station can configure up to two SRS resource sets with different resource type values ​​for the UE in the SRS-ResourceSet, which serves as higher-layer signaling.

[0401] Regarding the above details, each SRS resource set may include two SRS resources, and the two corresponding SRS resources may be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set may consist of two SRS ports, and the two SRS ports of the corresponding SRS resource may be connected to different UE antenna ports.

[0402] As an example, first and second SRS resources (each consisting of two SRS ports) can be included in a corresponding SRS resource set. The two SRS ports of the first and second SRS resources can be connected to different UE antenna ports. The two SRS ports of the first SRS resource can transmit at a first OFDM symbol location, and the two SRS ports of the second SRS resource can transmit at a second OFDM symbol location. In this case, the first and second OFDM symbol locations can be different from each other, but the time slot locations can be the same or different from each other.

[0403] [1T4R]

[0404] Regarding UE 1T4R operation, higher-layer signaling related to a combination of at least one of the following details from the base station can be configured, and operation can be performed based on this.

[0405] If the UE reports some or all of the SRS-AntennaSwitching2SP-1Periodic-r17, SRS-ExtensionAperiodicSRS-r17, and SRS-OneAP-SRS-r17 (which are UE capability reports),

[0406] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17, the base station can configure at most one (e.g., 0 or 1) SRS resource set for the UE in the SRS-ResourceSet, which is a higher-layer signaling layer, with a resource type value of "periodic" or "semi-persistent". As an example, the base station can configure one of the following details for the UE.

[0407] An SRS resource set with a resource type value of "periodic" or "semi-persistent" is not configured in the SRS-ResourceSet, which is used as a high-level signaling layer.

[0408] An SRS resource set with a resource type value of "periodic" in the SRS-ResourceSet, which is used as a high-level signaling layer.

[0409] An SRS resource set with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling.

[0410] Regarding the above details, each SRS resource set may include four SRS resources, and the four SRS resources may be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set may consist of one SRS port, and one SRS port of the corresponding SRS resource may be connected to different UE antenna ports.

[0411] As an example, the first to fourth SRS resources, each consisting of one SRS port, can be included in the corresponding SRS resource set. One SRS port of the first to fourth SRS resources can be connected to different UE antenna ports. One SRS port of the first to fourth SRS resources can transmit at the first to fourth OFDM symbol locations. The first to fourth OFDM symbol locations can be different from each other, but the time slot locations can be the same or different from each other.

[0412] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17, the base station can configure up to two SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as higher-layer signaling, and the base station can configure up to one SRS resource set with a resource type value of "periodic" for the UE in the SRS-ResourceSet as higher-layer signaling.

[0413] Regarding the above details, two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling, can not be activated simultaneously.

[0414] Regarding the above details, each SRS resource set may include four SRS resources, and the four SRS resources may be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set may consist of one SRS port, and one SRS port of the corresponding SRS resource may be connected to different UE antenna ports.

[0415] As an example, the first to fourth SRS resources, each consisting of one SRS port, can be included in the corresponding SRS resource set. One SRS port of the first to fourth SRS resources can be connected to different UE antenna ports. One SRS port of the first to fourth SRS resources can transmit at the first to fourth OFDM symbol locations. The first to fourth OFDM symbol locations can be different from each other, but the time slot locations can be the same or different from each other.

[0416] Based on the reports from the UE between srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17 (which is the UE capability report), the higher-layer signaling configuration of the base station and the operation of the UE can be expected as follows.

[0417] If the UE does not report both srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17, the base station can configure 0 or 2 SRS resource sets with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling.

[0418] When the UE reports both srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17, the base station can configure 0, 1, 2 or 4 SRS resource sets with a resource type value of "aperiodic" in the SRS-ResourceSet, which is used as higher-layer signaling.

[0419] When the UE only reports srs-ExtensionAperiodicSRS-r17 (in srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17), the base station can configure 0, 2 or 4 SRS resource sets with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet as higher-layer signaling.

[0420] If the UE only reports srs-OneAP-SRS-r17 from srs-ExtensionAperiodicSRS-r17 and srs-OneAP-SRS-r17, the base station can configure 0, 1, or 2 SRS resource sets with a resource type value of "aperiodic" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling.

[0421] Regarding the above details, when an SRS resource set is configured, each SRS resource set can include four SRS resources. The four SRS resources can be transmitted at different OFDM symbol locations in the same time slot. Each SRS resource in the corresponding SRS resource set can be composed of one SRS port, and one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0422] As an example, the first to fourth SRS resources, each consisting of one SRS port, can be included in the corresponding SRS resource set. One SRS port of the first to fourth SRS resources can be connected to different UE antenna ports. One SRS port of the first to fourth SRS resources can transmit in the same time slot at the first to fourth OFDM symbol locations, and the first to fourth OFDM symbol locations can be different from each other.

[0423] Regarding the above details, when two SRS resource sets are configured, Each SRS resource set may include two SRS resources, or the first SRS resource set may include one SRS resource and the second SRS resource set may include three SRS resources.

[0424] The corresponding SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations within the same time slot, and SRS transmissions for the corresponding SRS resource set can be performed in different time slots. During SRS transmissions between different SRS resources in different SRS resource sets, SRS can be transmitted at the same or different OFDM symbol locations, but the time slot locations can be different.

[0425] The corresponding SRS resource can consist of one SRS port, and one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0426] As an example, first and second SRS resources (each consisting of one SRS port) may be included in the first SRS resource set, and third and fourth SRS resources (each consisting of one SRS port) may be included in the second SRS resource set. One SRS port of each of the first to fourth SRS resources may be connected to different UE antenna ports. One SRS port of each of the first and second SRS resources may be transmitted at the first and second OFDM symbol locations in the same time slot, and the first and second OFDM symbol locations 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 locations in a time slot different from the time slots used to transmit the first and second SRS resources, and the third and fourth OFDM symbol locations may be different from each other. In this case, the first OFDM symbol location may be the same as or different from the third and fourth OFDM symbol locations, and the second OFDM symbol location may be the same as or different from the third and fourth OFDM symbol locations.

[0427] As another example, a first SRS resource consisting of one SRS port may be included in the first SRS resource set, and second to fourth SRS resources, each consisting of 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 different UE antenna ports. One SRS port of the first SRS resource may be transmitted at the first OFDM symbol location in a certain time slot. One SRS port of each of the second to fourth SRS resources may be transmitted at the second to fourth OFDM symbol locations in a different time slot than the time slot used to transmit the first SRS resource, and the second and fourth OFDM symbol locations may be different from each other. In this case, the first OFDM symbol location may be the same as or different from the second to fourth OFDM symbol locations.

[0428] Regarding the above details, when four SRS resource sets are configured, each SRS resource set can include one SRS resource. The four SRS resources can be transmitted at the same or different OFDM symbol locations in each time slot, and SRS transmissions for the corresponding SRS resource sets can be performed in different time slots. Each SRS resource in the corresponding SRS resource set can consist of one SRS port, and one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0429] As an example, the first to fourth SRS resources can 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 can be connected to different UE antenna ports, one SRS port of the first to fourth SRS resources can be transmitted at the first to fourth OFDM symbol positions in different time slots, and the first to fourth OFDM symbol positions in each time slot can be the same or different from each other, but the time slot positions can be different from each other.

[0430] If the UE fails to report all of the following UE capabilities: SRS-AntennaSwitching2SP-1Periodic-r17, SRS-ExtensionAperiodicSRS-r17, and SRS-OneAP-SRS-r17 (which are UE capability reports), that is, if none of these three UE capabilities are reported, The base station can configure at most one (i.e., 0 or 1) SRS resource set for the UE in the SRS-ResourceSet, which is used as higher-layer signaling, with resource type values ​​of "periodic" or "semi-persistent".

[0431] Regarding the above details, each SRS resource set may include four SRS resources, and the four SRS resources may be transmitted at different OFDM symbol locations. Each SRS resource in the corresponding SRS resource set may consist of one SRS port, and one SRS port of the corresponding SRS resource may be connected to different UE antenna ports.

[0432] As an example, the first to fourth SRS resources, each consisting of one SRS port, can be included in the corresponding SRS resource set. One SRS port of the first to fourth SRS resources can be connected to different UE antenna ports. One SRS port of the first to fourth SRS resources can transmit at the first to fourth OFDM symbol locations. The first to fourth OFDM symbol locations can be different from each other, but the time slot locations can be the same or different from each other.

[0433] The base station can configure 0 or 2 SRS resource sets with a resource type value of "aperiodic" in the SRS-ResourceSet, which serves as higher-layer signaling, for the UE. When two SRS resource sets are configured, some or all of the following details can be considered.

[0434] Each SRS resource set may include 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.

[0435] The corresponding SRS resources within each SRS resource set can be transmitted at different OFDM symbol locations within the same time slot, and SRS transmissions for the corresponding SRS resource set can occur in different time slots. SRS transmissions between different SRS resources in different SRS resource sets can occur at the same or different OFDM symbol locations, but the time slot locations can be different.

[0436] Each SRS resource may include one SRS port, and one SRS port of a corresponding SRS resource may be connected to a different UE antenna port.

[0437] As an example, first and second SRS resources (each consisting of one SRS port) may be included in the first SRS resource set, and third and fourth SRS resources (each consisting of 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 different UE antenna ports. One SRS port of the first and second SRS resources may be transmitted at the first and second OFDM symbol locations in the same time slot, and the first and second OFDM symbol locations may be different from each other. One SRS port of the third and fourth SRS resources may be transmitted at the third and fourth OFDM symbol locations in a time slot different from the time slot in which the first and second SRS resources are transmitted, and the third and fourth OFDM symbol locations may be different from each other. In this case, the first OFDM symbol location may be the same as or different from the third and fourth OFDM symbol locations, and the second OFDM symbol location may be the same as or different from the third and fourth OFDM symbol locations.

[0438] As another example, a first SRS resource consisting of one SRS port may be included in the first SRS resource set, and second to fourth SRS resources, each consisting of 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 different UE antenna ports. One SRS port of the first SRS resource may be transmitted at the first OFDM symbol location in a certain time slot. One SRS port of each of the second to fourth SRS resources may be transmitted at the second to fourth OFDM symbol locations in a different time slot than the time slot used to transmit the first SRS resource, and the second and fourth OFDM symbol locations may be different from each other. In this case, the first OFDM symbol location may be the same as or different from the second to fourth OFDM symbol locations.

[0439] Regarding the above details, this applies when multiple SRS resource sets are configured (e.g., when two or four SRS resource sets are configured).

[0440] The UE may expect the base station to configure the same p0, alpha, pathlossReferenceRS, and srs-PowerControlAdjustmentStates values ​​in all SRS resource sets. These are power control parameters that can be configured in each SRS resource set via higher-layer signaling. For example, the UE may expect multiple SRS resource sets to have the same power control parameters. This type of limitation may be referred to as [power control parameter limitation] below.

[0441] [Power control parameter limitation] can only be applied to SRS resource sets whose resource type values ​​are configured as "non-periodic" by the base station for the UE in the SRS-ResourceSet as higher-layer signaling.

[0442] [Power control parameter limitation] can only be applied to SRS resource sets whose resource type values ​​are configured by the base station for the UE in the SRS-ResourceSet as "periodic", "semi-persistent" or "aperiodic" in higher-layer signaling.

[0443] The UE can expect the base station to configure the value of aperiodicSRS-ResourceTrigger (as a higher-layer signaling) or the value of an entry in AperiodicSRS-ResourceTriggerList (as a higher-layer signaling) to be the same across all SRS resource sets. Such a restriction may be referred to below as [aperiodic SRS triggering restriction].

[0444] In this context, the aperiodicSRS-ResourceTrigger, configured by the base station in the SRS resource set as higher-layer signaling, refers to aperiodic SRS triggering state information. When the UE receives an aperiodic SRS triggering information about a specific aperiodic SRS triggering state from the base station via DCI, and the value configured in the aperiodicSRS-ResourceTrigger as higher-layer signaling corresponds to the aperiodic SRS triggering state indicated by the corresponding DCI, the UE can perform aperiodic SRS transmission with respect to the corresponding SRS resource set.

[0445] Similarly, the AperiodicSRS-ResourceTriggerList, which is configured by the base station as higher-layer signaling in the SRS resource set, includes multiple aperiodic SRS trigger state information. When the UE receives an aperiodic SRS trigger regarding a specific aperiodic SRS trigger state from the base station via DCI, and the aperiodic SRS trigger state indicated by the corresponding DCI is included among multiple values ​​configured in the AperiodicSRS-ResourceTriggerList as higher-layer signaling, the UE can perform aperiodic SRS transmission with respect to the corresponding SRS resource set.

[0446] While aperiodicSRS-ResourceTrigger, as a higher-layer signaling, provides a function that allows the corresponding SRS resource set to be included in a single aperiodic SRS triggering state, aperiodicSRS-ResourceTriggerList, also as a higher-layer signaling, provides a function that allows the corresponding SRS resource set to be included in multiple aperiodic SRS triggering states, thereby increasing the likelihood that the corresponding SRS resource set can be triggered by the base station.

[0447] [Aperiodic SRS Trigger Restriction] can only be applied to SRS resource sets whose resource type values ​​are configured as "aperiodic" by the base station for the UE in the SRS-ResourceSet as higher-layer signaling.

[0448] The UE can expect from the base station that the slotOffset for higher-layer signaling within the corresponding SRS resource set can have different values. Such limitations can be referred to as [Slot Offset Details] below.

[0449] [Time Slot Offset Details] can only be applied to SRS resource sets whose resource type values ​​are configured as "non-periodic" by the base station for the UE in the SRS-ResourceSet as higher-layer signaling.

[0450] [1T1R, 2T2R, 4T4R]

[0451] Regarding the 1T1R, 2T2R and 4T4R operations of the UE, higher-layer signaling related to a combination of at least one of the following details from the base station can be configured, and operations can be performed based on this.

[0452] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17 (which is the UE capability report), the base station can configure up to two SRS resource sets for the UE.

[0453] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17 (which is the UE capability report), the UE can receive higher-layer signaling configuration from the base station, as shown below.

[0454] There are two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet as high-level signaling, and one SRS resource set with a resource type value of "periodic" in the SRS-ResourceSet as high-level signaling.

[0455] Regarding the above details, two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as high-level signaling, can not be activated simultaneously.

[0456] Up to two SRS resource sets

[0457] Each SRS resource set includes one SRS resource, and in the cases of 1T1R, 2T2R, and 4T4R, the number of SRS ports configured in the corresponding SRS resource can be 1, 2, and 4, respectively.

[0458] The UE may not expect that, in the cases of 1T1R, 2T2R, and 4T4R, SRS transmissions associated with two or more SRS resource sets having a usage as a higher-layer signaling configured as “antennaSwitching” can be configured or triggered at the same OFDM symbol location.

[0459] [1T6R]

[0460] Regarding UE 1T6R operations, higher-layer signaling related to a combination of at least one of the following details from the base station can be configured, and operations can be performed based on this.

[0461] The base station can configure the UE with at most one (i.e., 0 or 1) SRS resource set with a resource type value of "periodic" in the SRS-ResourceSet, which is used as higher-layer signaling. An SRS resource set can include six SRS resources. Each SRS resource can be composed of one SRS port. The corresponding SRS resources can be transmitted in the same or different time slots at different OFDM symbol locations, and one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0462] The UE can receive configurations related to an SRS resource set with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as higher-layer signaling, as shown below.

[0463] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure at most one (i.e., 0 or 1) SRS resource set with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as higher-layer signaling.

[0464] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure up to two (i.e., 0, 1, or 2) SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as a higher-layer signaling, and the two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet as a higher-layer signaling can not be activated at the same time.

[0465] An SRS resource set may include six SRS resources, each of which may consist of one SRS port. The corresponding SRS resources may be transmitted in the same or different time slots at different OFDM symbol locations, and one SRS port of the corresponding SRS resource may be connected to different UE antenna ports.

[0466] The base station can configure up to three (i.e., 0, 1, 2 or 3) SRS resource sets with a resource type value of "aperiodic" in the SRS-ResourceSet, which is used as higher-layer signaling, for the UE.

[0467] When an SRS resource set is configured, it may include six SRS resources, each of which may consist of one SRS port. The corresponding SRS resources may be transmitted at different OFDM symbol locations in the same time slot, and one SRS port of the corresponding SRS resource may be connected to different UE antenna ports.

[0468] With two SRS resource sets configured, a total of six SRS resources can be divided and included in the two SRS resource sets. Each SRS resource can consist of one SRS port. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots, and one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0469] As an example, the UE may include first to third SRS resources in a first SRS resource set, and may include fourth to sixth SRS resources in a second SRS resource set. Transmissions of the first to third SRS resources in the first SRS resource set may be performed in a first time slot at the first to third OFDM symbol positions, and the first to third OFDM symbol positions may be different from each other. Transmissions of the fourth to sixth SRS resources in the second SRS resource set may be performed in a second time slot at the fourth to sixth OFDM symbol positions, and the fourth to sixth OFDM symbol positions may be different from each other. The first and second time slot positions may be different from each other, and the first to third OFDM symbol positions may be the same as or different from the fourth to sixth OFDM symbol positions.

[0470] As another example, it is also possible for the first and second SRS resource sets to include one (e.g., the first SRS resource) and five (e.g., the second to sixth SRS resources) SRS resources, respectively, and other combinations are not excluded.

[0471] With three SRS resource sets configured, a total of six SRS resources can be divided and included in the three SRS resource sets. Each SRS resource can consist of one SRS port. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots, and one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0472] As an example, the UE can include the first and second SRS resources in the first SRS resource set, the third and fourth SRS resources in the second SRS resource set, and the fifth and sixth SRS resources in the third SRS resource set. Transmissions of the first and second SRS resources in the first SRS resource set can be performed in the first time slot at the first and second OFDM symbol locations, and the first and second OFDM symbol locations can be different from each other. Transmissions of the third and fourth SRS resources in the second SRS resource set can be performed in the second time slot at the third and fourth OFDM symbol locations, and the third and fourth OFDM symbol locations can be different from each other. Transmissions of the fifth and sixth SRS resources in the third SRS resource set can be performed in the third time slot at the fifth and sixth OFDM symbol locations, and the fifth and sixth OFDM symbol locations can be different from each other. In this case, the first, second, and third time slot locations can be different from each other, and the first and second OFDM symbol locations, the third and fourth OFDM symbol locations, and the fifth and sixth OFDM symbol locations can be the same or different from each other.

[0473] As another example, it is also possible for the first, second, and third SRS resource sets to 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), respectively, and other combinations are not excluded.

[0474] [1T8R]

[0475] Regarding UE 1T8R operations, higher-layer signaling related to a combination of at least one of the following details from the base station can be configured, and operations can be performed based on this.

[0476] The base station can configure at most one (i.e., 0 or 1) SRS resource set with a resource type value of "periodic" in the SRS-ResourceSet, which serves as higher-layer signaling. An SRS resource set can include eight SRS resources, each of which can consist of one SRS port. The corresponding SRS resources can be transmitted in the same or different time slots at different OFDM symbol locations, and one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0477] The UE can receive configurations related to an SRS resource set with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as higher-layer signaling, as shown below.

[0478] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure at most one (i.e., 0 or 1) SRS resource set with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as higher-layer signaling.

[0479] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure up to two (i.e., 0, 1, or 2) SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as a higher-layer signaling, and the two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet as a higher-layer signaling can not be activated at the same time.

[0480] An SRS resource set may include eight SRS resources, each of which may consist of one SRS port. The corresponding SRS resources may be transmitted in the same or different time slots at different OFDM symbol locations, and one SRS port of the corresponding SRS resource may be connected to different UE antenna ports.

[0481] The base station can configure 0, 2, 3 or 4 SRS resource sets with a resource type value of "aperiodic" in the SRS-ResourceSet, which serves as higher-layer signaling, for the UE.

[0482] With two SRS resource sets configured, a total of eight SRS resources can be divided and included in the two SRS resource sets. Each SRS resource can consist of one SRS port. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots. Furthermore, one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0483] As an example, the UE may include first to fourth SRS resources in a first SRS resource set and fifth to eighth SRS resources in a second SRS resource set. Transmissions of the first to fourth SRS resources in the first SRS resource set may be performed in a first time slot at the first to fourth OFDM symbol positions, and these first to fourth OFDM symbol positions may be different from each other. Transmissions of the fifth to eighth SRS resources in the second SRS resource set may be performed in a second time slot at the fifth to eighth OFDM symbol positions, and these fifth to eighth OFDM symbol positions may be different from each other. In this case, the first and second time slot positions may be different from each other, and the first to fourth OFDM symbol positions may be the same as or different from the fifth to eighth OFDM symbol positions.

[0484] As another example, it is also possible for the first and second SRS resource sets to include one (e.g., the first SRS resource) and seven (e.g., the second to the eighth SRS resources) SRS resources, respectively, and other combinations are not excluded.

[0485] With three SRS resource sets configured, a total of eight SRS resources can be divided and included in the three SRS resource sets. Each SRS resource can consist of one SRS port. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots. Furthermore, one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0486] As an example, the UE can 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. Transmissions of the first to third SRS resources in the first SRS resource set can be performed in the first time slot at the first to third OFDM symbol positions, and these first to third OFDM symbol positions can be different from each other. Transmissions of the fourth to sixth SRS resources in the second SRS resource set can be performed in the second time slot at the fourth to sixth OFDM symbol positions, and these fourth to sixth OFDM symbol positions can be different from each other. Transmissions of the seventh and eighth SRS resources in the third SRS resource set can be performed in the third time slot at the seventh and eighth OFDM symbol positions, and these seventh and eighth OFDM symbol positions can be different from each other. In this case, the positions of the first, second, and third time slots can be different from each other, and the positions of the first to third OFDM symbols, the fourth to sixth OFDM symbols, and the seventh and eighth OFDM symbols can be the same or different from each other.

[0487] As another example, it is also possible for the first, second, and third SRS resource sets to 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), respectively, and other combinations are not excluded.

[0488] With four SRS resource sets configured, a total of eight SRS resources can be divided and included in the four SRS resource sets. Each SRS resource can consist of one SRS port. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots. Furthermore, one SRS port of the corresponding SRS resource can be connected to different UE antenna ports.

[0489] As an example, the UE can include the first and second SRS resources in the first SRS resource set, the third and fourth SRS resources in the second SRS resource set, the fifth and sixth SRS resources in the third SRS resource set, and the seventh and eighth SRS resources in the fourth SRS resource set. Transmissions of the first and second SRS resources in the first SRS resource set can be performed in the first time slot at the first and second OFDM symbol locations, and the first and second OFDM symbol locations can be different from each other. Transmissions of the third and fourth SRS resources in the second SRS resource set can be performed in the second time slot at the third and fourth OFDM symbol locations, and the third and fourth OFDM symbol locations can be different from each other. Transmissions of the fifth and sixth SRS resources in the third SRS resource set can be performed in the third time slot at the fifth and sixth OFDM symbol locations, and the fifth and sixth OFDM symbol locations can be different from each other. Transmissions of the seventh and eighth SRS resources in the fourth SRS resource set can be performed in the fourth time slot at the seventh and eighth OFDM symbol locations, and the seventh and eighth OFDM symbol locations can be different from each other. In this case, the positions of the first to fourth time slots can be different from each other, and the positions of the first and second OFDM symbols, the third and fourth OFDM symbols, the fifth and sixth OFDM symbols, and the seventh and eighth OFDM symbols can be the same or different from each other.

[0490] As another example, the first, second, third and fourth SRS resource sets may 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), respectively. Other combinations are not excluded.

[0491] [2T6R]

[0492] Regarding UE 2T6R operations, higher-layer signaling related to a combination of at least one of the following details from the base station can be configured, and operations can be performed based on this.

[0493] The base station can configure at most one (i.e., 0 or 1) SRS resource set with a resource type value of "periodic" for the UE in the SRS-ResourceSet, which serves as higher-layer signaling. An SRS resource set can include three SRS resources, each of which can consist of two SRS ports. The corresponding SRS resources can be transmitted in the same or different time slots at different OFDM symbol locations, and the two SRS ports of the corresponding SRS resources can be connected to different UE antenna ports.

[0494] The UE can receive configuration from the base station related to an SRS resource set with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as higher-layer signaling, as shown below.

[0495] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure at most one (i.e., 0 or 1) SRS resource set with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as higher-layer signaling.

[0496] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure up to two (i.e., 0, 1, or 2) SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as a higher-layer signaling, and the two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet as a higher-layer signaling can not be activated at the same time.

[0497] An SRS resource set may include three SRS resources, each SRS resource may include two SRS ports, the corresponding SRS resources may be transmitted in the same or different time slots at different OFDM symbol locations, and the two SRS ports of the corresponding SRS resource may be connected to different UE antenna ports.

[0498] The base station can configure up to three (i.e., 0, 1, 2 or 3) SRS resource sets with a resource type value of "aperiodic" in the SRS-ResourceSet, which is used as higher-layer signaling, for the UE.

[0499] When an SRS resource set is configured, it can include three SRS resources. Each SRS resource can consist of two SRS ports. The corresponding SRS resources can be transmitted at different OFDM symbol locations in the same time slot, and the two SRS ports of the corresponding SRS resources can be connected to different UE antenna ports.

[0500] With two SRS resource sets configured, a total of three SRS resources can be divided and included in the two SRS resource sets. Each SRS resource can consist of two SRS ports. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots. Furthermore, the two SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0501] As an example, the UE may include first and second SRS resources in a first SRS resource set, and may include a third SRS resource in a second SRS resource set. Transmissions of the first and second SRS resources in the first SRS resource set may be performed in a first time slot at the first and second OFDM symbol locations, and the first and second OFDM symbol locations may be different from each other. Transmissions of the third SRS resource in the second SRS resource set may be performed in a second time slot at the third OFDM symbol location. In this case, the first and second time slot locations may be different from each other, and the first and second OFDM symbol locations may be the same as or different from the third OFDM symbol location.

[0502] As another example, it is also possible for the first and second SRS resource sets to include one (e.g., the first SRS resource) and two (e.g., the second and third SRS resources) SRS resources, respectively, and other combinations are not excluded.

[0503] With three SRS resource sets configured, a total of three SRS resources can be divided and included in the three SRS resource sets. Each SRS resource can consist of two SRS ports. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots, and the two SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0504] As an example, the UE can 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 of the first SRS resource in the first SRS resource set can be performed at the first OFDM symbol position in the first time slot. Transmission of the second SRS resource in the second SRS resource set can be performed at the second OFDM symbol position in the second time slot. Transmission of the third SRS resource in the third SRS resource set can be performed at the third OFDM symbol position in the third time slot. In this case, the positions of the first, second, and third time slots can be different from each other, and the positions of the first to third OFDM symbols can be the same or different from each other.

[0505] [2T8R]

[0506] Regarding the UE's 2T8R operation, higher-layer signaling related to a combination of at least one of the following details from the base station can be configured, and operation can be performed based on this.

[0507] The base station can configure at most one (i.e., 0 or 1) SRS resource set with a resource type value of "periodic" for the UE in the SRS-ResourceSet, which is used as higher-layer signaling. An SRS resource set can include four SRS resources. Each SRS resource can consist of two SRS ports. The corresponding SRS resources can be transmitted in the same or different time slots at different OFDM symbols, and the two SRS ports of the corresponding SRS resources can be connected to different UE antenna ports.

[0508] The UE can receive configurations related to an SRS resource set with a resource type value of "semi-persistent" in the SRS-ResourceSet, which serves as higher-layer signaling, as shown below.

[0509] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure at most one (i.e., 0 or 1) SRS resource set with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as higher-layer signaling.

[0510] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure up to two (i.e., 0, 1, or 2) SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as a higher-layer signaling, and the two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet as a higher-layer signaling can not be activated at the same time.

[0511] An SRS resource set may include four SRS resources, each SRS resource may consist of two SRS ports, the corresponding SRS resources may be transmitted in the same or different time slots at different OFDM symbol locations, and the two SRS ports of the corresponding SRS resource may be connected to different UE antenna ports.

[0512] The base station can configure 0, 2, 3 or 4 SRS resource sets with a resource type value of "aperiodic" in the SRS-ResourceSet, which serves as higher-layer signaling, for the UE.

[0513] When an SRS resource set is configured, it can include four SRS resources. Each SRS resource can consist of two SRS ports. The corresponding SRS resources can be transmitted at different OFDM symbol locations in the same time slot, and the two SRS ports of the corresponding SRS resources can be connected to different UE antenna ports.

[0514] With two SRS resource sets configured, a total of four SRS resources can be divided and included in the two SRS resource sets. Each SRS resource can consist of two SRS ports. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots. Furthermore, the two SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0515] As an example, the UE may include first and second SRS resources in a first SRS resource set, and may include third and fourth SRS resources in a second SRS resource set. Transmissions of the first and second SRS resources in the first SRS resource set may be performed in a first time slot at the first and second OFDM symbol locations, and the first and second OFDM symbol locations may be different from each other. Transmissions of the third and fourth SRS resources in the second SRS resource set may be performed in a second time slot at the third and fourth OFDM symbol locations, and the third and fourth OFDM symbol locations may be different from each other. In this case, the first and second time slot locations may be different from each other, and the first and second OFDM symbol locations may be the same as or different from the third and fourth OFDM symbol locations.

[0516] As another example, it is also 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 are not excluded.

[0517] With three SRS resource sets configured, a total of four SRS resources can be divided and included in the three SRS resource sets. Each SRS resource can include two SRS ports. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots. Furthermore, the two SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0518] As an example, the UE can 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. Transmissions of the first and second SRS resources in the first SRS resource set can be performed in a first time slot at the first and second OFDM symbol locations, and the first and second OFDM symbol locations can be different from each other. Transmissions of the third SRS resource in the second SRS resource set can be performed in a second time slot at the third OFDM symbol location. Transmissions of the fourth SRS resource in the third SRS resource set can be performed in a third time slot at the fourth OFDM symbol location. In this case, the locations of the first, second, and third time slots can be different from each other, and the first to fourth OFDM symbol locations can be the same or different from each other.

[0519] As an example, it is also possible for the first, second, and third SRS resource sets to 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), respectively, and other combinations are not excluded.

[0520] With four SRS resource sets configured, a total of four SRS resources can be divided and included in the four SRS resource sets. Each SRS resource can consist of two SRS ports. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots, and the two SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0521] As an example, the UE may include the first, second, third, and fourth SRS resources in the first, second, third, and fourth SRS resource sets respectively. Transmissions of the first, second, third, and fourth SRS resources in the first, second, third, and fourth SRS resource sets may be performed at the first, second, third, and fourth OFDM symbol positions in the first, second, third, and fourth time slots respectively. The positions of the first to fourth time slots may be different from each other, and the positions of the first to fourth OFDM symbols may be the same or different from each other.

[0522] [4T8R]

[0523] Regarding the 4T8R operation of the UE, higher-layer signaling related to a combination of at least one of the following details from the base station can be configured, and operation can be performed based on this.

[0524] If the UE does not report srs-AntennaSwitching2SP-1Periodic-r17 (which is the UE capability report), The base station can configure up to two (e.g., 0, 1, or 2) SRS resource sets for the UE in the SRS-ResourceSet, which is used as higher-layer signaling, with resource type values ​​of "periodic" or "semi-persistent". As an example, the base station can configure one of the following details for the UE.

[0525] An SRS resource set with a resource type value of "periodic" or "semi-persistent" is not configured in the SRS-ResourceSet, which is used as a high-level signaling layer.

[0526] An SRS resource set with a resource type value of "periodic" in the SRS-ResourceSet, which is used as a high-level signaling layer.

[0527] An SRS resource set with a resource type value of "semi-persistent" in the SRS-ResourceSet, which is used as a high-level signaling layer.

[0528] The SRS-ResourceSet, which serves as high-level signaling, contains an SRS resource set with a resource type value of "periodic" and an SRS resource set with a resource type value of "semi-persistent".

[0529] Regarding the above details, each SRS resource set may include two SRS resources, each SRS resource may consist of four SRS ports, the corresponding SRS resources may be transmitted in the same or different time slots at different OFDM symbol locations, and the four SRS ports of the corresponding SRS resource may be connected to different UE antenna ports.

[0530] When the UE reports srs-AntennaSwitching2SP-1Periodic-r17 as a UE capability report, the base station can configure up to two (i.e., 0, 1, or 2) SRS resource sets with a resource type value of "semi-persistent" for the UE in the SRS-ResourceSet as a higher-layer signaling. The base station can also configure up to one (i.e., 0 or 1) SRS resource set with a resource type value of "periodic" for the UE in the SRS-ResourceSet as a higher-layer signaling. Furthermore, the two SRS resource sets with a resource type value of "semi-persistent" in the SRS-ResourceSet as a higher-layer signaling can not be activated simultaneously.

[0531] Each SRS resource set may include two SRS resources, each SRS resource may consist of four SRS ports, the corresponding SRS resources may be transmitted in the same or different time slots at different OFDM symbol locations, and the four SRS ports of the corresponding SRS resource may be connected to different UE antenna ports.

[0532] The base station can configure 0, 1 or 2 SRS resource sets with a resource type value of "aperiodic" in the SRS-ResourceSet, which serves as higher-layer signaling, for the UE.

[0533] When an SRS resource set is configured, it can include two SRS resources, each of which can consist of four SRS ports. The corresponding SRS resources can be transmitted at different OFDM symbol locations in the same time slot, and the four SRS ports of the corresponding SRS resources can be connected to different UE antenna ports.

[0534] With two SRS resource sets configured, a total of two SRS resources can be divided and included in the two SRS resource sets. Each SRS resource can consist of four SRS ports. All SRS resources in each SRS resource set can be transmitted at different OFDM symbol locations in the same time slot. SRS transmissions for different SRS resource sets can be performed at the same or different OFDM symbol locations in different time slots. Furthermore, the four SRS ports of the corresponding SRS resource can be connected to different UE antenna ports.

[0535] As an example, the UE may include the first and second SRS resources in the first and second SRS resource sets, respectively, and the transmission of the first and second SRS resources in the first and second SRS resource sets may be performed in the first and second time slots at the first and second OFDM symbol locations, respectively. In this case, the first and second time slot locations may be different from each other, and the first and second OFDM symbol locations may be the same or different from each other.

[0536] When the UE performs antenna switching operations, i.e., when the UE transmits different SRS resources associated with different antenna ports, a time interval of approximately 15 μs is typically required between any two adjacent SRS resources transmitted. Therefore, the (minimum) protection period can be defined as shown in Table 29 below: [Table 29]

[0537] In Table 29, μ refers to the parameter set, Δf refers to the subcarrier spacing, and Y can refer to the number of OFDM symbols representing the guard period, i.e., the duration of the guard period. Referring to Table 29, the guard period can be configured based on parameter μ, which determines the parameter set. The UE is configured not to transmit any different signals during the guard period, and the guard period can be configured to be used entirely for antenna switching.

[0538] As an example, a protection period can be configured between the transmission time points of two adjacent SRS resources based on SRS resources transmitted at different OFDM symbol locations in the same time slot.

[0539] As another example, if a UE has two SRS resource sets configured for antenna switching purposes, if these two corresponding SRS resource sets are configured or triggered to transmit in two consecutive time slots, and if the UE reports a UE capability indicating that the UE can transmit SRS at all OFDM symbol locations within the time slot, based on Table 29 above, the UE can anticipate that: between the last OFDM symbol transmitting SRS in the first time slot performing SRS transmission with respect to the first SRS resource set and the first OFDM symbol transmitting SRS in the second time slot performing SRS transmission with respect to the second SRS resource set, there may be a protection period for antenna switching corresponding to at least Y OFDM symbols. For example, the time difference between two SRS transmissions may actually be greater than or equal to Y OFDM symbols.

[0540] Regarding this inter-slot protection period, similar to the protection period between two SRS resources within the aforementioned time slot, if the actual time difference between the last SRS transmission in the first time slot and the first SRS transmission in the next time slot corresponds to Y OFDM symbols, the UE may not transmit any signal within the Y OFDM symbol interval.

[0541] Regarding this inter-slot protection period, if the actual time difference between the last SRS transmission in the first time slot and the first SRS transmission in the next time slot corresponds to Y OFDM symbols in two consecutive time slots, and if all SRS transmissions before and after the protection period are dropped (cancelled) due to overlap with other signals, the UE can determine to drop (cancel) the inter-slot protection period defined by Y OFDM symbols by applying the same priority as SRS transmissions before and after the protection period, and if it is determined to drop, uplink transmissions can be performed within the inter-slot protection period.

[0542] Regarding all the antenna switching schemes mentioned above, the UE can expect the same number of SRS ports to be configured for use in all SRS resources in all SRS resource sets that have higher-layer signaling purposes configured by the base station as "antennaSwitching" in the SRS resource set.

[0543] Regarding the antenna switching schemes based on 1T24, 1T4R, 2T4R, 1T6R, 1T8R, 2T6R, 2T8R and 4T8R operations, the UE may not expect that two or more SRS resource sets with higher-layer signaling uses configured by the base station as "antennaSwitching" can be configured or triggered in the same time slot.

[0544] Regarding antenna switching schemes based on 1T1R, 2T2R, and 4T4R operations, the UE may not expect that two or more SRS resource sets with higher-layer signaling uses configured by the base station as "antennaSwitching" can be configured or triggered in the same OFDM symbol.

[0545] Figure 11 This is a diagram illustrating an SRS antenna switching operation according to an embodiment of the present disclosure.

[0546] refer to Figure 11 This illustrates a scenario where the UE operates based on 1T4R, and the UE can have two aperiodic SRS resource sets configured for it (e.g., SRS resource sets #0 and #1). The UE can receive PDCCH from base station 1100, and aperiodic SRS triggering associated with SRS resource set #0 1110 and SRS resource set #1 1120 can be indicated by the PDCCH. In this case, the slot offset value associated with SRS resource set #0 1110 can be configured by slotOffset as higher-layer signaling, which can have a value of 1, and the aperiodic SRS transmission associated with SRS resource set #0 can be performed one slot after the slot in which the PDCCH is received (i.e., in slot #1). Furthermore, the slot offset value associated with SRS resource set #1 1120 can be configured as slotOffset as higher-layer signaling, with a value of 2, and the aperiodic SRS transmission associated with SRS resource set #1 can be performed two slots after the slot from which the PDCCH is received (i.e., in slot #2).

[0547] SRS resources #0 1111 and #1 1112, included in SRS resource set #0 1110, are transmitted at different OFDM symbol locations in time slot #1, and here, Y OFDM symbols can exist as a protection period between SRS resource #0 and SRS resource #1 1113. Furthermore, during the transmission of SRS resource #0 1130, the UE can connect an SRS port to its first receive antenna port 1135 to perform SRS transmission, and during the transmission of SRS resource #1 1140, the UE can connect an SRS port to its second receive antenna port 1145 to perform SRS transmission.

[0548] SRS resources #2 1121 and #3 1122, included in SRS resource set #1 1120, are transmitted at different OFDM symbol locations in time slot #1, and here, Y OFDM symbols can exist as a protection period between SRS resources #2 and #3 1123. Furthermore, during the transmission of SRS resource #2 1150, the UE can connect one SRS port to its third receive antenna port 1155 to perform SRS transmission, and during the transmission of SRS resource #3 1160, the UE can connect one SRS port to its fourth receive antenna port 1165 to perform SRS transmission.

[0549] By connecting the four SRS resources #0 to #3 to different receive antenna ports of the UE and then transmitting SRS, the UE can transmit SRS from all different receive antenna ports to obtain information about the channels connected to all receive antennas of the UE, and the base station can thus obtain information about the channels between the base station and the UE and use it for uplink or downlink scheduling.

[0550] [SRS: Carrier Switching]

[0551] Next, SRS carrier handover will be described. In TDD systems, SRS carrier handover is used to perform SRS transmission to support downlink channel estimation for base stations in supporting cells that are not configured for PUSCH / PUCCH transmission (i.e., cells that only support downlink transmission). Due to the channel reciprocity established between the downlink and uplink channels in TDD systems, the base station can estimate the downlink channel based on the uplink channel estimated via SRS. When the base station uses a large number of antennas for support but the UE uses a relatively small number of antennas, the method of estimating the downlink channel based on SRS channel reciprocity has the advantage of requiring less overhead compared to the method of estimating the downlink channel based on CSI-RS.

[0552] To transmit SRS to a cell that only supports downlink transmission via SRS carrier handover, the UE should use an RF transmitter to perform uplink transmission to one of the other cells. The target cell used to perform the SRS carrier handover (hereinafter referred to as the target cell or target component carrier (CC)) is located in a frequency band used to support downlink transmission that only supports PUCCH / PUSCH transmissions without configuration therein. The UE does not use the RF transmitter except for the purpose of SRS carrier handover. Therefore, considering the cost of the UE, there is no need to separately deploy an RF transmitter for uplink transmission to the target cell to perform SRS carrier handover, and when SRS carrier handover is scheduled (in the following, scheduling for performing SRS carrier handover can include all non-periodic (AP) triggering based on downlink control information (DCI) format 2_3, semi-persistent (SP) triggering based on higher layer configuration, and periodic (P) triggering), the UE can transmit SRS by retuning the RF transmitter to perform uplink transmission to another cell. The cell in which the RF transmitter is deployed before the UE retunes to perform SRS carrier handover can be defined as the source cell (hereinafter referred to as the source cell or source CC), which can be defined in the UE via higher-layer parameters. srs- SwitchFromServCellIndex and srs-SwitchFromCarrier Configure. High-level parameters. srs- SwitchFromServCellIndex Indicates the cell index of the source CC, and srs-SwitchFromCarrier Indicate one of the NUL and SUL of the target CC to determine the RF transmitter that the UE needs to retune.

[0553] During SRS carrier handover, the UE requires retuning time. This time is the time required for the source CC's RF transmitter to prepare to transmit SRS to the target CC, and the time required to retune the RF transmitter back to the source CC after transmitting all SRS to the target CC. This is additional time required besides the preparation time for transmitting SRS (for purposes other than SRS carrier handover). As mentioned above, regarding the retuning time required by the RF transmitter before and after SRS carrier handover, the UE can report its capabilities to the base station and notify the base station of the required time. In this case, the UE can... switchingTimeUL and switchingTimeDL Report the retuning time of the RF transmitter to the base station.

[0554] Because the UE retunes the RF transmitter in the source CC to perform SRS carrier handover, the UE can transmit uplink signals (e.g., PUCCH, PUSCH, or SRS) to the source CC while transmitting SRS to the target CC. Therefore, to perform SRS carrier handover, the UE first identifies whether the uplink transmission scheduled for the source CC overlaps with the SRS transmission, including the RF retuning time. If the uplink transmission scheduled for the source CC overlaps with the SRS transmission scheduled for the target CC (including the retuning time), and simultaneous transmission after the UE's indicated UL CA capability is not possible, the UE can compare the priorities of the two signals and transmit only one uplink signal. Here, the SRS carrier handover priorities defined in NR Release 15 / 16 are as follows: If the PUSCH or PUCCH in the source CC (which includes one or more pieces of information such as HARQ-ACK / positive scheduling request (SR) / rank indicator (RI) / CSI-RS resource indicator (CRI) / SS / PBCH block resource indicator (SSBRI) and / or physical random access channel (PRACH)) overlaps with the SRS transmission in the target CC, the UE may not transmit the SRS of the target CC. For example, the UE can transmit the scheduled uplink signal on the source CC without performing an SRS carrier handover.

[0555] If a PUSCH containing aperiodic CSI in the source CC overlaps with a periodic or semi-persistent SRS transmission in the target CC, the UE may not transmit the periodic or semi-persistent SRS of the target CC. For example, the UE may transmit scheduled uplink signals on the source CC without performing an SRS carrier handover.

[0556] If a PUCCH or PUSCH in the source CC that includes periodic or semi-persistent CSI (which includes one or more pieces of information such as Channel Quality Indicator (CQI) / Precoding Matrix Indicator (PMI) / L1-RSRP / L1-SINR and / or SRS) overlaps with an SRS transmission in the target CC, the UE may not transmit the PUCCH or PUSCH and / or SRS of the source CC. For example, the UE may perform an SRS carrier handover to transmit the SRS to the target CC.

[0557] If the PUSCH in the source CC, which includes aperiodic CSI (which includes one or more pieces of information from only CQI / PMI / L1-RSRP / L1-SINR), overlaps with the aperiodic SRS transmission in the target CC, the UE may not transmit the PUSCH of the source CC. For example, the UE may perform an SRS carrier handover to transmit the aperiodic SRS to the target CC.

[0558] When comparing the priorities between uplink transmissions at the source CC and SRS transmissions at the target CC, the UE should consider the time required to receive and decode the DCI to schedule each transmission, the time required to determine the uplink transmission based on the higher-layer configuration, the preparation time required to perform uplink signal transmission, and the SRS transmission preparation time including the RF retuning time of the target CC. This is because if the UE prepares for either an uplink transmission at the source CC or an SRS transmission at the target CC, it cannot cancel it. For example, when the UE prepares for an SRS transmission to a scheduled target CC (considering all preparation times, such as DCI decoding and RF retuning time), even if it receives a DCI for scheduling uplink signal transmissions with a higher priority than the source CC, the UE may not cancel the SRS transmission to the target CC. This situation is classified as a scheduling error, and the base station should consider the following conditions when performing SRS carrier handover. To cancel a specific transmission (uplink signal transmission in the source CC or SRS transmission in the target CC), the UE in carrier c1 (target CC) symbol N C1 SRS transmission is initiated in the middle, and the UE targets the carrier. (Source CC) symbol Conflicting uplink transmissions in the network are addressed by applying the aforementioned priority rules (priority rules between uplink transmissions of the source CC and SRS transmissions of the destination CC) under the following conditions: The UE should receive the DCI such that the last symbol of the PDCCH is consistent with... The interval between them is at least greater than N2 symbols plus The obtained value, and the last symbol of PDCCH is... The interval between them is at least greater than N2 symbols. In this case, the DCI can correspond to both the DCI used in the source CC to schedule uplink signal transmission and the DCI used in the target CC to schedule SRS transmission.

[0559] based on Semi-persistent CSI reports or SRS transmissions are at least greater than N2 symbols plus The interval at which the obtained value was previously activated, and based on It should be activated at least before an interval of N2 symbols. In this case, the activated transmission can include both uplink transmissions in the source CC and SRS transmissions in the destination CC.

[0560] Here, Corresponding to =max{ switchingTimeUL , switchingTimeDL}, and the time interval unit of OFDM symbols is based on , This is determined by the minimum subcarrier spacing (SCS) in the corresponding scheduling cell (if overlapping uplink signals are not transmitted to the target CC or source CC). N2 represents the processing capacity based on the UE's capabilities for PUSCH preparation time, which will be described later.

[0561] When a UE receives an SRS request for target CC c via DCI (or grant) and transmits the nth aperiodic SRS, the UE may begin SRS transmission to the configured symbols and time slots that meet the following conditions: The configured symbols and time slots correspond to the sum of values ​​later than the following detailed conditions.

[0562] The maximum time interval among N OFDM symbols of a cell that includes target CC c and DCI (or license), respectively.

[0563] From high-level parameters SRS-SwitchingTimeNR of switchingTimeUL and switchingTimeDL Defined uplink or downlink RF retuning time.

[0564] It does not conflict with any previous SRS transmission (the SRS transmission before the nth aperiodic SRS) and will not be interrupted by uplink or downlink RF retuning time.

[0565] If the above conditions are not met, the UE will not perform the transmission of the nth SRS. Here, N refers to the minimum time interval (in symbol units) between the aperiodic SRS used to trigger the aperiodic SRS and the DCI, and corresponds to the value reported as a UE capability.

[0566] In the case of inter-band carrier aggregation (CA), the UE can transmit SRS and PUCCH / PUSCH simultaneously for component carriers (CC) of different frequency bands based on the UE's capabilities.

[0567] In the case of inter-band carrier aggregation (CA), the UE can transmit PRACH and SRS simultaneously for component carriers (CC) of different frequency bands based on the UE's capabilities.

[0568] Figure 12 An SRS carrier switching according to an embodiment of the present disclosure is illustrated.

[0569] refer to Figure 12 The DCI 1201 received from the target CC 1200 can schedule the SRS transmission 1202 via SRS carrier switching. The DCI 1211 received from the source CC 1210 can schedule the uplink transmission 1212, which can overlap with the SRS transmission 1202. Here, based on the SRS transmission start symbol... 1203, should at least be added to the symbol N2 1204. The value obtained at 1205 was received before two DCIs (1206). Furthermore, the uplink transmission start symbol in the source CC was used. 1213, at least two DCIs (1215) should be received before N2 1214. Figure 11 This is a diagram illustrating an SRS antenna switching operation according to an embodiment of the present disclosure.

[0570] exist Figure 12 In the figure, reference numeral 1207 indicates the time required for RF retuning from the downlink to the uplink to perform SRS carrier handover, and reference numeral 1208 indicates the time required for RF retuning from the uplink to the downlink after performing SRS carrier handover.

[0571] [Related to UE Capability Report]

[0572] In LTE and NR, a UE can perform a process of reporting its supported capabilities to the corresponding base station while the UE is connected to the serving base station. In the following description, this is referred to as UE capability reporting.

[0573] A base station can send a UE capability query message requesting capability reports to a UE in a connected state. This message can include UE capability requests for each Radio Access Technology (RAT) type of the base station. Requests for each RAT type can include supported frequency band combination information. Furthermore, in the case of a UE capability query message, UE capabilities for each of multiple RAT types can be requested by a single RRC message container sent by the base station, or the base station can include a UE capability query message (containing multiple UE capability requests for each RAT type) and send it to the UE. For example, a UE capability query can be repeated multiple times within a single message, and the UE can construct corresponding UE capability information messages and report the message multiple times. In next-generation mobile communication systems, UE capability requests can be made for NR, LTE, E-UTRA-NR Dual Connectivity (EN-DC), and Multiple RAT Dual Connectivity (MR-DC). Additionally, UE capability query messages are generally initially transmitted after the UE connects to the base station, but can also be requested at any time when the base station needs them.

[0574] After the UE has received the UE Capability Report Request from the base station in the above operations, the UE constructs its capabilities based on the RAT type and frequency band information requested by the base station. The methods for constructing UE capabilities in the NR system are summarized below.

[0575] 1. When a UE receives a list of LTE and / or NR frequency bands from a base station via a UE capability request, the UE constitutes a frequency band combination (BC) for EN-DC and NR Standalone (SA) networking. For example, the UE constructs a candidate list of BCs for EN-DC and NR SA based on the frequency bands in the FreqBandList requested from the base station. Furthermore, the frequency bands have priorities as described in the FreqBandList.

[0576] 2. When the base station sets the “eutra-nr-only” flag or the “eutra” flag and requests a UE capability report, the UE completely removes the NR SA BC from the candidate list of the BCs it constitutes. This operation may only occur when the LTE base station (eNB) requests “eutra” capability.

[0577] 3. Subsequently, the UE removes the backed-down BC from the candidate list of BCs formed by the above operations. A backed-down BC is a BC obtained by removing the frequency band corresponding to at least one SCell from the predetermined BCs, and the BC before removing the frequency band corresponding to at least one SCell may have already covered the backed-down BC, therefore the backed-down BC can be omitted. This operation applies to MR-DC, i.e., LTE frequency bands. The BCs remaining after the operation correspond to the final "candidate BC list".

[0578] 4. The UE selects the BC of the requested RAT type applicable to the final "Candidate BC List" and selects the BC to be reported. In this operation, the UE constructs the supportedBandCombinationList according to the determined order. For example, the UE can construct the BC to be reported and the UE capabilities according to the pre-configured rat-Type order (nr->eutra-nr->eutra). In addition, the UE constructs a featureSetCombination for the constructed supportedBandCombinationList and constructs a list of "Candidate Feature Set Combinations" from the list of candidate BCs from which fallback BCs (including capabilities of the same or lower level) are removed. The "Candidate Feature Set Combinations" can include all feature set combinations for NR and EUTRA-NR BCs and can be obtained from the feature set combinations of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0579] 5. Furthermore, when the requested rat type is eutra-nr and has effects, featureSetCombinations are included in both containers of UE-MRDC-Capabilities and UE-NR-Capabilities. However, the NR feature set only includes UE-NR-Capabilities.

[0580] After establishing UE capabilities, the UE sends a UE capability information message, including the UE capabilities, to the base station. Subsequently, the base station performs scheduling and transmit / receive management applicable to the corresponding UE based on the UE capabilities received from the UE.

[0581] In the following description, embodiments of the present disclosure will be illustrated with reference to the accompanying drawings. The content of this disclosure is applicable to both Frequency Division Duplex (FDD) and TDD systems. In the following, higher-layer signaling (or higher-layer signaling) in this disclosure refers to a method for delivering signals from a base station to a UE using a downlink data channel of the physical layer or from a UE to a base station using an uplink data channel of the physical layer, and may be referred to as RRC signaling, PDCP signaling, or Media Access Control (MAC) control element (CE).

[0582] In the following, within this disclosure, when the UE determines whether to apply cooperative communication, the UE may use various methods, such as applying a specific format to the PDCCH used to allocate the PDSCH with cooperative communication applied, including a specific indicator indicating whether the PDCCH used to allocate the PDSCH with cooperative communication applied, scrambling the PDCCH used to allocate the PDSCH with cooperative communication applied using a specific RNTI, or assuming that cooperative communication is applied within a specific interval indicated by a higher layer. For ease of description below, receiving a PDSCH with cooperative communication applied at the UE under similar conditions described above may be referred to as the NC-JT case.

[0583] In the following, in this disclosure, determining the priority between A and B may be mentioned in a variety of ways, such as selecting the one with higher priority according to a predetermined priority rule and performing the corresponding operation, or omitting or discarding the operation with lower priority.

[0584] In the following, the examples described by way of various embodiments in this disclosure are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0585] In the following text, for ease of description, the cell, transmission point, panel, beam, and / or transmission direction, which can be distinguished by higher-layer / L1 parameters (such as TCI status or spatial relationship information, cell ID, TRP ID, or panel ID), can be collectively described as Transmitter Receiver Point (TRP), beam, or TCI status. Therefore, in practical applications, TRP, beam, or TCI status can be appropriately replaced by one of the aforementioned terms.

[0586] In the following, within this disclosure, the UE may use various methods to determine whether cooperative communication is applied. For example, the PDCCH to which cooperative communication is applied has a specific format, or the PDCCH to which cooperative communication is applied includes a specific indicator indicating whether cooperative communication is applied, or the PDCCH to which cooperative communication is applied is scrambled by a specific RNTI, or it is assumed that cooperative communication is applied within a specific interval indicated by a higher layer. In the following, for ease of description, the case where the UE receives a PDSCH to which cooperative communication is applied based on conditions similar to those described above is referred to as the NC-JT case.

[0587] In the following description, embodiments of the present disclosure will be illustrated with reference to the accompanying drawings. In this context, a base station refers to an entity that allocates resources to terminals and may be at least one of a gNode B, gNB, eNode B, Node B, base station (BS), radio access unit, base station controller, and nodes on a network. Terminals may include user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. Although embodiments of the present disclosure will be described below with reference to a 5G system as an example, embodiments of the present disclosure can also be applied to other communication systems with similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communications and mobile communication technologies developed after 5G may be included therein. Therefore, embodiments of the present disclosure, with partial modifications, are also applicable to other communication systems without substantially departing from the scope of the present disclosure as understood by those skilled in the art. The contents of this disclosure apply to both FDD and TDD systems.

[0588] Furthermore, in the following description of this disclosure, detailed descriptions of relevant functions or components will be omitted where such description would unnecessarily obscure the main points of this disclosure. The terminology used herein is defined according to the functions defined in this disclosure and may vary depending on the intent, practice, etc., of the user / operator. Therefore, it should be defined based on the overall content of this disclosure.

[0589] In the following description of this disclosure, higher-level signaling can refer to signaling corresponding to at least one of the following signaling, or a combination of one or more of them.

[0590] Master Information Block (MIB)

[0591] System Information Block (SIB) or SIB X (X=1, 2, ...)

[0592] Radio Resource Control (RRC)

[0593] Media Access Control (MAC) Control Element (CE).

[0594] Additionally, L1 signaling can refer to signaling corresponding to at least one of the signaling methods that use physical layer channels or signaling, or a combination of one or more of them.

[0595] Physical Downlink Control Channel (PDCCH)

[0596] Downlink Control Information (DCI)

[0597] UE-specific DCI; Group public DCI; Public DCI; DCI scheduling (e.g., DCI used for scheduling downlink or uplink data). Non-scheduled DCI (e.g., DCI not used for the purpose of scheduling downlink or uplink data). Physical Uplink Control Channel (PUCCH) Uplink control information (UCI).

[0598] In the following, in this disclosure, determining the priority between A and B may be mentioned in a variety of ways, such as selecting the one with higher priority according to a predetermined priority rule and performing the corresponding operation, or omitting or discarding the operation with lower priority.

[0599] As used herein, the term “slot” can generally refer to a specific time unit corresponding to a transmission time interval (TTI), specifically a slot used in a 5G NR system, or a slot or subframe used in a 4G LTE system.

[0600] The above examples can be described below through various embodiments of this disclosure, but these embodiments are not independent of each other, and one or more embodiments can be applied simultaneously or in combination.

[0601] As described above, SRS carrier handover is used to estimate the downlink channel by transmitting SRS for a supporting cell (or carrier), where PUSCH / PUCCH transmission is not configured in the TDD system, i.e., a carrier that only supports downlink reception. In the following description of various embodiments of this disclosure, performing or transmitting SRS carrier handover can be interpreted as having the same meaning as transmitting SRS in a carrier that only supports downlink reception via SRS carrier handover. Since channel reciprocity is established between the uplink channel and the downlink channel, the base station can obtain downlink channel information between the base station and the UE based on the uplink channel estimated through the received SRS. In a carrier that only supports downlink reception, the UE may only have components for receiving and may not have an RF link for transmitting, etc. Therefore, in order to transmit SRS in the corresponding downlink-dedicated carrier, the UE can temporarily borrow the RF link of another carrier that can transmit the uplink channel and use that link to transmit the SRS of the downlink-dedicated carrier. For ease of explanation, a carrier with an RF link and uplink transmission capability is defined as c2 (or source cell, source CC, disturbed cell, or disturbed CC), and a dedicated downlink carrier for performing SRS carrier handover is defined as c1 (or target cell or target CC). In this case, a temporary restriction occurs on the uplink channel transmission of c2 associated with the RF link used to transmit SRS to c1 (all carriers affected by the RF link and carrier c2 can be considered and can be represented as a set S(c2)). If the corresponding RF link does not support the function of transmitting uplink channels to multiple carriers simultaneously, then during the time interval of the RF link used for SRS transmission to c1 (the corresponding time interval may include not only the time used to transmit SRS but also the time used to tune the RF link to accommodate the carrier), uplink channel transmission to c2 (or all carriers in the set S(c2) including c2) may not be performed. If an SRS transmitted from c1 and an uplink channel (e.g., PUCCH, PUSCH, or SRS) transmitted from c2 are scheduled for the same time resources, the UE can select and transmit either the SRS transmitted from c1 or the uplink channel transmitted from c2 according to the defined priority, and discard the other.

[0602] If the UE performs an SRS carrier handover on c1, the UE can use the RF link borrowed from c2 to transmit SRS resources in an SRS resource set configured for "antennaSwitching" on c1. The SRS used for antenna handover can be transmitted through the UE's corresponding receive antenna (as described above) and can be used by the base station to obtain downlink channel information via channel reciprocity. Similarly, the base station can perform an SRS carrier handover on c1, which does not support PUSCH / PUCCH transmission, using an SRS resource set configured for "antennaSwitching". This is because, from the perspective of using SRS to obtain downlink channel information, an SRS resource set with the same functionality must be used. The difference between SRS antenna handover and SRS carrier handover is that performing SRS carrier handover requires additional processing to tune the RF link to make it suitable for SRS transmission on the corresponding carrier. Apart from this difference, SRS antenna handover and SRS carrier handover can operate similarly in terms of using SRS to obtain downlink channel information.

[0603] To acquire downlink channel information using SRS carrier handover in c1 without PUSCH / PUCCH transmission configured in a TDD system, various time-domain behaviors can be used to schedule SRS. More specifically, to support DCI-based aperiodic SRS triggering, DCI format 1_1, DCI format 1_2, and DCI format 2_3 can be used. If the base station triggers SRS carrier handover using DCI format 2_3, the UE can simultaneously schedule SRS carrier handover for multiple CCs configured with higher-layer parameters and tune the RF link sequentially according to defined rules to transmit SRS on the corresponding CCs. In this case, the defined rules can be defined as performing SRS carrier handover sequentially according to the order of the CCs configured with higher-layer parameters. For example, if the UE performs SRS carrier handover for c1_1 and c1_2, and c1_1 is configured to precede c1_2 in the higher-layer parameter configuration structure (e.g., it can be configured earlier in the configuration sequence, or it can be configured with a lower index value), then the UE can perform SRS carrier handover for c1_1 first, and then perform SRS carrier handover for c1_2. If the base station can trigger SRS carrier handover using DCI format 1_1 or 1_2, the base station can schedule SRS carrier handover to be performed using a supporting cell (or carrier) indicated by DCI format 1_1 or 1_2, which is different from SRS carrier handover triggered by DCI format 2_3. For example, the base station can schedule multiple SRS carrier handovers for multiple carriers using DCI format 2_3, and schedule a single SRS carrier handover for a single carrier using DCI format 1_1 or 1_2.

[0604] Figure 13 An aperiodic SRS carrier switching schedule according to an embodiment of the present disclosure is illustrated.

[0605] refer to Figure 13 The base station can send DCI format 2_3 1301 to the UE. One DCI format 2_3 1301 can schedule the UE to perform multiple SRS carrier handovers sequentially on multiple carriers (e.g., c1_1 and c1_2 and c1_3 and c1_4) 1302, 1303, 1304, 1305. As another example, the base station can send DCI formats 1_1 1311, 1315 to the UE. The first DCI format 1_1 1311 can schedule the UE to perform a single SRS carrier handover on a single carrier c1_1 1312. Another second DCI format 1_1 1315 can schedule the UE to perform a single SRS carrier handover on another single carrier c1_2 1316.

[0606] Figure 14 This is a diagram illustrating aperiodic SRS switching scheduled on the same time resources according to an embodiment of the present disclosure.

[0607] refer to Figure 14 The first example illustrates a scenario where the base station schedules the UE to perform SRS carrier handover 1402 and 1412 on two different carriers, c1_1 and c1_2, using two carriers with the same time resources. If corresponding RF links are required to perform SRS carrier handover 1402 and 1412 (i.e., two different RF links are required in the corresponding example), the UE can borrow RF links from at least two different carriers and perform tuning to c1_1 and c1_2 respectively to transmit SRS. If the UE uses only two or fewer RF links for uplink transmission, the UE may not be able to perform two different SRS carrier handovers scheduled on the same time resources simultaneously, as in the first case. On the other hand, if the UE uses two or more RF links for uplink transmission and can simultaneously tune both c1_1 and c1_2 to transmit SRS (all SRS resources in the SRS resource set are configured for "antennaSwitching"), then, as in the first case, it can simultaneously perform handover of two different SRS carriers scheduled for the same time resources. In this case, the UE may require additional UE capabilities to simultaneously tune two RF links and may also require some additional capabilities to simultaneously perform SRS carrier handover.

[0608] In the second example, the base station uses DCI format 2_3 1421 to schedule the UE to perform two SRS carrier handovers 1422 and 1423 sequentially on two different carriers c1_1 and c1_2. Furthermore, the base station can send DCI format 1_1 1431 to the UE to perform an SRS carrier handover 1432 on another carrier c1_3 within the same time resource as one of the two SRS carrier handovers scheduled using DCI format 2_3 1421, the SRS carrier handover 1422. For example, the UE can receive DCI format 2_3 1421 and DCI format 1_1 1431 from the base station and be scheduled to perform two different SRS carrier handovers 1422 and 1432 on different carriers c1_1 and c1_3 within the same time resource.

[0609] like Figure 14 In the two examples shown, the base station can send a DCI to the UE to schedule the UE to perform different SRS carrier handovers on multiple different carriers within the same time resource. In this case, depending on the UE implementation, the UE can perform multiple SRS carrier handovers simultaneously or not simultaneously. If the UE can perform multiple SRS carrier handovers simultaneously and reports its ability to perform simultaneous SRS carrier handovers to the base station, the base station will be able to schedule as many SRS carrier handovers as the UE can perform within the same time resource, thereby acquiring downlink channel information more quickly. Alternatively, if the UE cannot perform multiple SRS carrier handovers simultaneously or does not report its ability to perform simultaneous SRS carrier handovers to the base station, the base station can determine that the UE cannot perform simultaneous SRS carrier handovers and can avoid scheduling multiple SRS carrier handovers within the same time resource through scheduling constraints, or should support the UE in explicitly selecting which SRS carrier handover to perform by introducing new priority rules in overlapping cases.

[0610] In a first embodiment of this disclosure, a UE capability is defined for simultaneously supporting multiple SRS carrier handovers on multiple carriers based on the UE's capabilities, and a specific description is given of the transmission / reception operations performed between the base station and the UE based on whether the corresponding UE capability has been reported. In a second embodiment of this disclosure, a method is specifically described for determining the SRS carrier handover to be performed by the UE based on priority and according to overlap rules (such as overlap rules or drop rules) when multiple SRS carrier handovers on multiple carriers are scheduled for the same time resources. In a third embodiment of this disclosure, a method is specifically described for a base station to restrict specific scheduling to avoid performing multiple SRS carrier handovers simultaneously in the same time resources.

[0611] First implementation method: A method for supporting simultaneous SRS carrier handover on multiple CA carriers based on UE capability reports.

[0612] In a first embodiment of this disclosure, a UE capability for simultaneously performing multiple SRS carrier handovers is specifically provided, where the base station schedules the UE to support carrier aggregation (CA) that aggregates multiple carriers and simultaneously performs SRS carrier handovers on multiple downlink dedicated carriers in the same time resources. Furthermore, when the UE reports its capability for simultaneously performing multiple SRS carrier handovers to the base station, a method for scheduling higher-layer parameters configured by the base station for the UE and SRS carrier handovers will be specifically described.

[0613] To enable a UE to simultaneously perform multiple different SRS carrier handovers on multiple carriers, the UE must first transmit multiple SRSs simultaneously. As described above, when a UE performs an SRS carrier handover, after tuning the RF link to a downlink dedicated carrier, the UE transmits an SRS resource set for the purpose of "antenna switching" to the base station via the downlink dedicated carrier. Upon receiving the SRS for antenna switching purposes, the base station estimates the uplink channel for the corresponding UE on the downlink dedicated carrier and uses the reciprocity of the estimated uplink channel to obtain downlink channel information. Therefore, the UE must at least have the capability to simultaneously transmit SRS for antenna switching on multiple CA carriers.

[0614] Based on the CA technology supported by the UE, the UE capability to simultaneously perform multiple SRS carrier handovers on multiple CA carriers can be specifically defined. Specific UE capabilities can be defined by distinguishing between cases where the UE supports in-band CA and cases where the UE supports inter-band CA.

[0615] Implementation 1-1: When the UE supports in-band CA, a method for defining the UE capability to support simultaneous SRS carrier switching on multiple CA carriers, and the operation of the UE and the base station based on the UE capability report.

[0616] In Implementation 1-1, when the UE supports in-band CA, the UE capability required to simultaneously perform (or transmit) multiple SRS carrier handovers on multiple CA carriers is proposed. Furthermore, the operation of the base station and the UE is described depending on whether the UE supports the technique of simultaneously performing multiple SRS carrier handovers on multiple CA carriers.

[0617] Before defining the UE capability for simultaneously performing multiple SRS carrier handovers on multiple CA carriers for UEs supporting in-band CA, it is necessary to allow the UE capability to simultaneously perform SRS antenna handovers on different carriers in an in-band CA environment. First, the UE must be implemented to operate in-band CA, and the corresponding UE can notify the base station that the UE supports in-band CA through a UE capability report. In this way, the UE can report CA-related UE capabilities to the base station through higher-layer parameters such as supportedBandCombinationList. If the UE can independently transmit SRS for antenna handover on different CCs according to the UE implementation method, the UE can report to the base station its UE capability to simultaneously perform SRS antenna handovers for in-band CA. For example, if the UE can operate separate RF links for multiple carriers within the same frequency band supporting in-band CA, and even if the antenna is switched to perform SRS antenna handover for any one carrier, as long as it does not affect the operation of the RF links of other carriers or only causes an acceptable level of interference, the UE can report to the base station its UE capability to perform multiple SRS antenna handovers for the corresponding frequency band. If the UE is able to transmit multiple SRS antenna handovers simultaneously under in-band CA conditions, the following UE capabilities can be configured as {supported} and reported to the base station: For simulTX-SRS-AntSwitchingIntraBandUL-CA, the following items in the detailed parameters of SimulSRS-ForAntennaSwitching are configured as {Supported} and reported to the base station. The detailed parameters are as follows: supportSRS-AntennaSwitching: If the UE supports in-band CA and can perform multiple antenna handovers simultaneously on multiple different carriers according to the UE capability report, the corresponding UE capability can be configured as {support} and reported to the base station. In this case, the UE can expect that the handover combination (configured as xTyR, where x represents the number of transmit antennas and y represents the number of receive antennas) between the transmit and receive antennas for multiple SRS antenna handovers performed simultaneously on multiple carriers will be configured identically. Furthermore, the UE can transmit SRS resources that overlap in the time domain and are transmitted on multiple carriers through the same UE antenna port. Alternatively, according to a more advanced UE implementation, the handover combination xTyR between the transmit and receive antennas for multiple SRS antenna handovers performed simultaneously on multiple carriers can be configured to different values. Furthermore, according to the UE implementation, the UE can utilize different UE antenna ports to construct and transmit SRS resources that overlap in the time domain and are transmitted on multiple carriers.

[0618] The UE can report the aforementioned UE capabilities to the base station as a prerequisite for executing one of the UE capability reports that notifies the base station that the UE can support multiple SRS carrier handovers in in-band CA mode. In the case of in-band CA, a UE that does not support the aforementioned UE capability of simultaneously performing SRS antenna handover may not perform multiple SRS carrier handovers simultaneously on multiple CA carriers. Alternatively, depending on the UE implementation, in the case of in-band CA, the UE may not perform SRS antenna handovers simultaneously, but may perform SRS carrier handovers concurrently. However, in this embodiment of the present disclosure, it is assumed that the UE capability of simultaneously performing multiple SRS antenna handovers should be supported as a prerequisite for the method of simultaneously performing multiple SRS carrier handovers.

[0619] In the case of in-band CA, in order for a UE to perform multiple SRS carrier handovers simultaneously on multiple CA carriers, additional UE capabilities may be required besides the CA-related UE capabilities and the UE capabilities related to simultaneous SRS carrier handovers as described above. First, the UE must have prior UE capabilities supporting SRS carrier handover. To prepare for transmitting multiple SRS carrier handovers within the same time resources, UE capabilities for RF tuning within time intervals and for retuning the RF to the initially supported carrier within time intervals after performing multiple SRS carrier handovers may be required. The RF tuning time performed by the UE before and after performing multiple SRS carrier handovers simultaneously can be reported as a value equal to or greater than the RF tuning time performed before and after performing a single SRS carrier handover (e.g., switchingTimeUL and switchingTimeDL included in SRS-SwitchingTimeNR). In this way, the RF tuning time required for performing multiple SRS carrier handovers simultaneously can constitute a component of higher-layer parameters for reporting new UE capabilities for simultaneous SRS carrier handovers: High-level parameters used to report new UE capabilities that perform multiple SRS carrier handovers simultaneously (e.g., it can be determined by any name to indicate that multiple SRS carrier handovers can be transmitted simultaneously in an in-band CA environment, such as simulTx-SRS-CarrierSwitchingIntraBandUL-CA or simulTx-SRS-CarrierSwitchingIntraBand, etc.).

[0620] A high-level parameter used to report the RF tuning time required to perform multiple SRS carrier switching simultaneously (e.g., it can be determined by any name to indicate the time required to perform RF tuning on multiple (or a single, depending on the UE implementation) RF links of the UE (can be in µs), such as switchingTimeUL and switchingTimeDL or additionalSwitchingTimeUL and additionalSwitchingTimeDL, etc.).

[0621] UE capabilities that support full overlap, partial overlap, or both full and partial overlap of multiple overlapping SRS carrier handovers in time-domain resources can be reported as individual UE capabilities, or as components of higher-layer parameters for reporting new UE capabilities that simultaneously transmit corresponding multiple SRS carrier handovers. Here, overlap can be considered not only as the time for transmitting SRS for antenna switching purposes, but also as the RF tuning time performed before and after SRS transmission.

[0622] Figure 15 This is a diagram illustrating the process of tuning an RF link and transmitting SRS in a situation where multiple SRS carrier switching is simultaneously transmitted in an in-band CA according to an embodiment of the present disclosure.

[0623] refer to Figure 15Assume the UE supports in-band CA and supports both uplink transmission and downlink reception of multiple carriers c2_1 and c2_2, while only supporting downlink reception of the remaining multiple carriers c1_1 and c1_2. In this case, assume the corresponding RF links 1501 and 1502 can operate on carriers c2_1 and c2_2 to support both uplink transmission and downlink reception. This is just an example, and depending on the UE implementation, one RF link can be used to support two carriers c2_1 and c2_2. The base station can utilize, for example, multiple DCI formats 1_1, or combinations of DCI formats 2_3 and 1_1, to schedule multiple carriers c1_1 and c1_2, enabling multiple SRS carrier handovers 1507 and 1508 to be performed within the same time resources. The UE can prepare to transmit SRS by tuning (1511) the RF from an operational carrier (e.g., c2_1) on an RF link (e.g., 1501) to a carrier (e.g., c1_1) on which an SRS carrier handover (e.g., 1507) will be performed. Similarly, another RF link (e.g., 1502) can be prepared to transmit SRS by tuning (1512) the RF from an operational carrier (e.g., c2_2) to a carrier (e.g., c1_2) on which an SRS carrier handover (e.g., 1508) will be performed. In this case, in order to perform multiple SRS carrier handovers 1507 and 1508 simultaneously on multiple carriers c1_1 and c1_2, the UE can perform RF tuning before transmitting SRS. Figure 15As shown, RF tuning 1511 or 1512 for simultaneously performing two SRS carrier handovers can be performed concurrently or sequentially. In some cases (simultaneous or sequential RF tuning), a UE capability report must be performed beforehand to ensure that SRS carrier handovers can be performed simultaneously within the same time resources. Whether RF tuning 1511 or 1512 is supported simultaneously or sequentially can be reported to the base station as a UE capability using higher-level parameters (e.g., switchingTimeUL and switchingTimeDL or additionalSwitchingTimeUL and additionalSwitchingTimeDL) to report the RF tuning time 1503 or 1504 required to simultaneously perform the aforementioned multiple SRS carrier handovers. Alternatively, without introducing higher-level parameters for reporting individual RF tuning times, existing switchingTimeUL and switchingTimeDL can be reported as RF tuning times, and the UE can be defined as capable of supporting simultaneous RF tuning. If the UE completes RF tuning for simultaneous SRS carrier handover within a given time, the UE can simultaneously transmit SRS resource sets 1507 and 1508 for multiple antenna handover purposes to multiple carriers c1_1 and c1_2. After the UE has performed all SRS carrier handovers 1507 and 1508 scheduled to multiple carriers c1_1 and c1_2 according to its capabilities, the UE can tune (1513, 1514) RF links 1501 and 1502 to make them available for uplink transmission on carriers c2_1 and c2_2. In this case, RF tuning can be performed as follows: Figure 15 The RF tuning can be performed simultaneously or sequentially. In some cases (simultaneous or sequential RF tuning), UE capability reporting must be performed first to ensure that SRS carrier handover can be performed simultaneously within the same time resources. Similarly, to report UE capabilities for RF tuning times 1505 or 1506 for each case, higher-level parameters (e.g., switchingTimeUL and switchingTimeDL or additionalSwitchingTimeUL and additionalSwitchingTimeDL) can be defined, and the UE can configure the values ​​of these parameters and report them to the base station. Alternatively, without introducing higher-level parameters for reporting individual RF tuning times, existing switchingTimeUL and switchingTimeDL can be reported as RF tuning times, and the UE can be defined as capable of performing simultaneous RF tuning.

[0624] In the case of in-band carrier aggregation (CA), depending on the UE's capabilities, SRS (or SRS resources) used for switching more than one SRS carrier can be transmitted simultaneously on different CCs (component carriers or carriers or frequency bands).

[0625] The above UE operation describes a scenario where, if the UE supports the capability to simultaneously perform multiple SRS carrier handovers and the base station schedules multiple SRS carrier handovers to be performed simultaneously within the same time resources, the UE performs SRS carrier handovers simultaneously without configuring additional RRC parameters. Conversely, the base station can configure new RRC parameters for the UE to support multiple SRS carrier handovers on multiple carriers. In the case of in-band CA, if the UE reports to the base station that it supports the capability to support multiple SRS carrier handovers simultaneously on multiple carriers, the base station can configure RRC parameters for the UE (these parameters can be defined as parameters with names indicating the corresponding operation, such as enableSimulTx_SRSCarrierSwitching or enable_multipleCarrierSwitching), with values ​​such as {Support} or {Enable}. Even if the base station has received from the UE the capability to support multiple SRS carrier handovers simultaneously, if the base station has not configured RRC parameters for the UE to support multiple SRS carrier handovers simultaneously, the UE may not expect the base station to schedule multiple SRS carrier handovers to be performed simultaneously on multiple carriers within the same time resources. If the UE does not report to the base station its ability to perform multiple SRS carrier handovers simultaneously, the base station will not configure RRC parameters for the UE to support the simultaneous execution of multiple SRS carrier handovers.

[0626] In the example described in Implementation 1-1, it is assumed that the DCI used for scheduling to perform multiple SRS carrier handovers simultaneously satisfies all timeline conditions used to determine whether the UE will perform an SRS carrier handover. Here, the timeline conditions refer to the guarantee time being greater than or equal to the sum of the following two: the time N2 required to decode the DCI and complete SRS transmission preparation before transmitting the first SRS transmitted during the SRS carrier handover (based on the last received symbol of the PDCCH including the DCI), and the time required to tune the RF to perform the SRS carrier handover. (Here, It can be defined as considering the maximum of max{switchingTimeUL, switchingTimeDL} or all the values ​​of the above additional tuning times.

[0627] Implementation 1-2: When the UE supports in-band CA, a method for defining the UE capability to simultaneously perform SRS carrier handover on multiple CA carriers, and the operation of the UE and base station based on the UE capability report.

[0628] In embodiments 1-2, when the UE supports in-band CA, the UE capability required to simultaneously perform multiple SRS carrier handovers on multiple CA carriers is proposed. Furthermore, the operation of the base station and the UE is described depending on whether the UE supports the technique of simultaneously performing multiple SRS carrier handovers on multiple CA carriers.

[0629] Before defining the UE capability for simultaneously performing (or transmitting) multiple SRS carrier handovers on multiple CA carriers for UEs supporting inter-band CA, it is necessary to allow the UE capability to simultaneously perform SRS antenna handovers on different carriers in an inter-band CA environment. First, the UE must be implemented as an inter-band CA operator, and the corresponding UE can notify the base station that the UE supports inter-band CA through a UE capability report. In this way, the UE can report CA-related UE capabilities to the base station through higher-layer parameters such as supportedBandCombinationList. If the UE can independently transmit SRS for antenna handover in different frequency bands and corresponding CCs within those bands, depending on the UE's implementation method, then the UE can report to the base station its capability to simultaneously perform SRS antenna handovers for inter-band CA. For example, if the UE can operate separate RF links for multiple carriers in a frequency band combination supporting inter-band CA, and if the switching antenna performing SRS antenna handover on one carrier does not affect the operation of the RF links on other carriers, or only causes acceptable interference, then the UE can report to the base station its capability to perform multiple SRS antenna handovers on multiple CA carriers within that frequency band combination. If the UE is able to transmit multiple SRS antenna handovers simultaneously under inter-band CA conditions, the following UE capabilities can be configured as {supported} and reported to the base station: For simulTX-SRS-AntSwitchingInterBandUL-CA, the following items in the detailed parameters of SimulSRS-ForAntennaSwitching are configured as {Supported} and reported to the base station. The detailed parameters are as follows: supportSRS-AntennaSwitching: If the UE supports inter-band CA and can simultaneously perform multiple antenna handovers on carriers in different frequency bands according to the corresponding UE capability report, the corresponding UE capability can be configured as {support} and reported to the base station. In this case, the UE can expect that the handover combination (configured as xTyR, where x represents the number of transmit antennas and y represents the number of receive antennas) between the transmit and receive antennas for multiple SRS antenna handovers simultaneously transmitted on multiple CCs in a combined frequency band will be configured identically. Furthermore, the UE can transmit SRS resources transmitted on multiple CCs in a combined frequency band that overlap in the time domain to the same UE antenna port. Alternatively, according to a more advanced UE implementation, the handover combination xTyR between the transmit and receive antennas for multiple SRS antenna handovers simultaneously transmitted on multiple CCs in a combined frequency band can be configured to different values. Furthermore, according to the UE implementation, the UE can utilize different UE antenna ports to construct and transmit SRS resources transmitted on multiple CCs in a combined frequency band that overlap in the time domain.

[0630] The UE can report the aforementioned UE capabilities to the base station as a prerequisite for executing one of the UE capability reports that notify the base station that the UE can support multiple SRS carrier handovers in inter-band CA scenarios. In the case of inter-band CA, a UE that does not support the aforementioned UE capability of simultaneously performing SRS antenna handover may not simultaneously perform multiple SRS carrier handovers on multiple CA carriers in a combination of multiple frequency bands. Alternatively, depending on the UE implementation, in the case of inter-band CA, the UE may not perform SRS antenna handovers simultaneously, but may perform SRS carrier handovers concurrently. However, in this embodiment of the present disclosure, it is assumed that the UE capability of simultaneously performing multiple SRS antenna handovers should be supported as a prerequisite for the method of simultaneously performing multiple SRS carrier handovers.

[0631] In the case of inter-band CA, in order for the UE to simultaneously perform multiple SRS carrier handovers on multiple CA carriers of a combination of multiple frequency bands, additional UE capabilities may be required besides the CA-related UE capabilities and the UE capabilities related to simultaneous SRS antenna handovers mentioned above. First, the UE must have UE capabilities that support SRS carrier handover in advance.

[0632] Unlike the case of supporting intra-band CA, in the case of inter-band CA, when the UE performs an SRS carrier handover in a frequency band composed of inter-band CA combinations, the UE can report to the base station the frequency bands that may be affected in uplink channel transmission due to the SRS carrier handover. If the SRS carrier handover performed in a frequency band composed of inter-band CA combinations affects other frequency bands, the following limitation occurs: when the UE performs an SRS carrier handover in one frequency band, it cannot transmit uplink channels through other frequency bands. In order for the UE to support inter-band CA and simultaneously perform multiple SRS carrier handovers on multiple CA carriers in combined frequency bands, the UE should be able to transmit uplink channels in other frequency bands when performing an SRS carrier handover in one frequency band. Therefore, in the case of supporting inter-band CA, performing an SRS carrier handover in one of the combined frequency bands should not affect other frequency bands. In addition, the UE can perform UE capability reporting so that even if the UE performs an SRS carrier handover for a frequency band combination supporting inter-band CA in one frequency band, the base station can determine that the UE can transmit uplink channels through another frequency band. For example, as a prerequisite for a UE supporting inter-band CA to support a method for simultaneously performing multiple SRS carrier handovers using carriers in multiple combined frequency bands, the UE should be able to operate independently of each other even when performing SRS carrier handovers on any frequency band in the band combination, and the UE should be able to report the relevant UE capabilities to the base station. Whether other frequency bands in the band combination are affected by the SRS carrier handover can be reported to the base station via the higher-layer parameter srs-SwitchingAffectedBandsListNR. srs-SwitchingAffectedBandsListNR can be reported to the base station by being included in the higher-layer parameters (i.e., BandParameters in BandCombination) to report the UE capabilities for the frequency bands in the band combination, and can be represented as a bit string indicating the other frequency bands in the band combination affected when performing SRS carrier handover using the corresponding frequency band. If the bit for other frequency bands in the corresponding band combination is configured to 1 and reported to the base station, it indicates that the SRS carrier handover performed using the corresponding frequency band will affect the other frequency bands. If the bits of other frequency bands combined with the corresponding frequency band are configured to 0 and reported to the base station, it indicates that the SRS carrier handover performed using the corresponding frequency band will not affect other frequency bands. Therefore, in order for UEs supporting inter-band CA to support the method of simultaneously performing multiple SRS carrier handovers on multiple carriers in a combined frequency band, the UE can configure all srs-SwitchingAffectedBandsListNR of the frequency band combination corresponding to the inter-band CA to 0 and report it to the base station.Alternatively, two or more bits in the bit string of srs-SwitchingAffectedBandsListNR can be configured to 0, and the UE can perform multiple SRS carrier handovers on carriers in multiple frequency bands that do not affect each other, even during SRS carrier handover. If two or more bits in the bit string of srs-SwitchingAffectedBandsListNR are configured to 0 and the remaining bits are configured to 1, the UE can perform multiple SRS carrier handovers simultaneously between frequency bands that do not affect each other during SRS carrier handover. In summary, in order for the UE to perform multiple SRS carrier handovers on multiple carriers of frequency band combinations in an inter-band CA environment, two or more bits in srs-SwitchingAffectedBandsListNR must be reported as 0, and during SRS handover, by reporting bits in srs-SwitchingAffectedBandsListNR as 0, it is possible to perform multiple SRS carrier handovers simultaneously on carriers in frequency band combinations that do not affect each other. If all frequency band combinations affect each other when performing SRS carrier handover in an inter-band CA environment, i.e., all bits of srs-SwitchingAffectedBandsListNR are reported as 1, the UE may not be able to support multiple SRS carrier handovers performed simultaneously in an inter-band CA environment.

[0633] To prepare for multiple SRS carrier handovers that should be performed within the same time resources, UE capabilities may be required to perform RF tuning within a certain time interval, and UE capabilities to retune the RF link to accommodate the initially supported carriers within a certain time interval after multiple SRS carrier handovers. The RF tuning time performed by the UE before and after performing multiple SRS carrier handovers simultaneously can be reported as a value equal to or greater than the RF tuning time performed before and after performing a single SRS carrier handover (e.g., switchingTimeUL and switchingTimeDL included in SRS-SwitchingTimeNR). In this way, the RF tuning time required for performing multiple SRS carrier handovers simultaneously can constitute a component of higher-layer parameters for reporting new UE capabilities for simultaneous SRS carrier handovers: High-level parameters used to report new UE capabilities that perform multiple SRS carrier handovers simultaneously (e.g., it can be determined by any name to indicate that multiple SRS carrier handovers can be transmitted simultaneously in an inter-band CA environment, such as simulTx-SRS-CarrierSwitchingInterBandUL-CA or simulTx-SRS-CarrierSwitchingInterBand, etc.).

[0634] A high-level parameter used to report the RF tuning time required to perform multiple SRS carrier switching simultaneously (e.g., it can be determined by any name to indicate the time required to perform RF tuning on multiple (or a single, depending on the UE implementation) RF links of the UE (can be in µs), such as switchingTimeUL and switchingTimeDL or additionalSwitchingTimeUL and additionalSwitchingTimeDL, etc.).

[0635] UE capabilities that support full overlap, partial overlap, or both full and partial overlap of multiple overlapping SRS carrier handovers in time-domain resources can be reported as individual UE capabilities, or as components of higher-layer parameters for reporting new UE capabilities that simultaneously transmit corresponding multiple SRS carrier handovers. Here, overlap can be considered not only as the time for transmitting SRS for antenna switching purposes, but also as the RF tuning time performed before and after SRS transmission.

[0636] Figure 16 This is a diagram illustrating the process of tuning an RF link and transmitting SRS in a situation where multiple SRS carrier switching is simultaneously transmitted in an inter-band CA according to an embodiment of the present disclosure.

[0637] refer to Figure 16Assume the UE supports inter-band CA and supports both uplink transmission and downlink reception of carriers c2_1 and c2_2 in multiple frequency bands (band 1 and band 2), and only supports downlink reception of the remaining carriers c1_1 and c1_2 in the corresponding frequency bands. In this case, assume the corresponding RF links 1601 and 1611 can operate on carriers c2_1 and c2_2 of the two frequency bands to support both uplink transmission and downlink reception. This is just an example, and depending on the UE implementation, one RF link can be used to support two carriers c2_1 and c2_2. The base station can use, for example, multiple DCI formats 1_1, or combinations of DCI formats 2_3 and 1_1, to schedule multiple carriers c1_1 and c1_2, such that multiple SRS carrier handovers 1604 and 1614 are transmitted within the same time resources. The UE can prepare to transmit SRS by tuning (1602) the RF from an operational carrier (e.g., c2_1 of band 1) on an RF link (e.g., 1601) to a carrier (e.g., c1_1) on which an SRS carrier handover (e.g., 1604) will be performed. Similarly, another RF link (e.g., 1611) can be prepared to transmit SRS by tuning (1612) the RF from an operational carrier (e.g., c2_2) to a carrier (e.g., c1_2) on which an SRS carrier handover (e.g., 1614) will be performed. In this case, in order to perform multiple SRS carrier handovers 1604 and 1614 simultaneously on multiple carriers c1_1 and c1_2, the UE can perform RF tuning before transmitting SRS. Figure 16As shown, RF tuning (1602 or 1612) for simultaneously performing two SRS carrier handovers can be performed concurrently or sequentially. In some cases (simultaneous or sequential RF tuning), a UE capability report must be performed beforehand to ensure that SRS carrier handovers can be performed simultaneously within the same time resources. Whether RF tuning (1602 or 1612) is supported simultaneously or sequentially can be reported to the base station as a UE capability using higher-level parameters (e.g., switchingTimeUL and switchingTimeDL or additionalSwitchingTimeUL and additionalSwitchingTimeDL) to report the RF tuning time 1603 or 1613 required to simultaneously perform the aforementioned multiple SRS carrier handovers. Alternatively, without introducing higher-level parameters for reporting individual RF tuning times, existing switchingTimeUL and switchingTimeDL can be reported as RF tuning times, and the capability for simultaneous RF tuning can be defined, requiring the UE to support this capability. If the UE completes RF tuning for simultaneous SRS carrier handover within a given time, the UE can simultaneously transmit SRS resource sets 1604 and 1614 for multiple antenna handover purposes to multiple carriers c1_1 and c1_2. After the UE has performed all SRS carrier handovers 1604 and 1614 scheduled to multiple carriers c1_1 and c1_2 according to its capabilities, the UE can tune (1606, 1616) RF links 1601 and 1611 to make them available for uplink transmission on carriers c2_1 and c2_2. In this case, RF tuning can be performed as follows: Figure 16 The RF tuning can be performed simultaneously or sequentially. In some cases (simultaneous or sequential RF tuning), UE capability reporting must be performed first to ensure that SRS carrier handover can be performed simultaneously within the same time resources. Similarly, to report UE capabilities for RF tuning times 1605 or 1615 for each case, higher-level parameters (e.g., switchingTimeUL and switchingTimeDL or additionalSwitchingTimeUL and additionalSwitchingTimeDL) can be defined, and the UE can configure the values ​​of these parameters and report them to the base station. Alternatively, without introducing higher-level parameters for reporting individual RF tuning times, existing switchingTimeUL and switchingTimeDL can be reported as RF tuning times, and the UE can be defined as capable of performing simultaneous RF tuning.

[0638] In the case of in-band carrier aggregation (CA), depending on the UE's capabilities, SRS (or SRS resources) used for switching more than one SRS carrier can be transmitted simultaneously on component carriers (CC) in different frequency bands.

[0639] The above UE operation describes a scenario where, if the UE supports the capability to simultaneously perform multiple SRS carrier handovers and the base station schedules multiple SRS carrier handovers to be performed simultaneously in the same time resources, the UE performs SRS carrier handovers simultaneously without configuring additional RRC parameters. Conversely, the base station can configure new RRC parameters for the UE to support multiple SRS carrier handovers on multiple carriers. In the case of inter-band CA, if the UE reports to the base station that it supports the capability to simultaneously perform multiple SRS carrier handovers on carriers in different frequency bands, the base station can configure RRC parameters for the UE (these parameters can be defined as parameters with names indicating the corresponding operation, such as enableSimulTx_SRSCarrierSwitching_InterbandCA or enable_multipleCarrierSwitching_InterbandCA), with values ​​such as {Support} or {Enable}. In an inter-band CA environment, even if the base station has received UE capability from the UE that supports simultaneous SRS carrier handover, if the base station has not configured RRC parameters for the UE to support simultaneous SRS carrier handover, the UE may not expect the base station to schedule multiple SRS carrier handovers to be performed simultaneously on multiple carriers within the same time resource. In an inter-band CA environment, if the UE does not report its capability to support simultaneous SRS carrier handover to the base station, the base station will not configure RRC parameters for the UE to support simultaneous SRS carrier handover.

[0640] In the examples described in Implementation 1-2, it is assumed that the DCI used for scheduling to perform multiple SRS carrier handovers simultaneously satisfies all timeline conditions used to determine whether the UE will perform an SRS carrier handover. Here, the timeline conditions refer to the guarantee time being greater than or equal to the sum of the following two: the time N2 required to decode the DCI and complete SRS transmission preparation before transmitting the first SRS transmitted during the SRS carrier handover (based on the last received symbol of the PDCCH including the DCI), and the time required to tune the RF to perform the SRS carrier handover. (Here, It can be defined as considering the maximum of max{switchingTimeUL, switchingTimeDL} or all the values ​​of the above additional tuning times.

[0641] Second implementation method: A method for determining the carrier to perform SRS carrier switching based on additional overlap rules.

[0642] In a second embodiment of this disclosure, when a base station schedules a UE to enable carrier aggregation (CA) that supports the aggregation of multiple carriers and simultaneously performs SRS carrier switching on multiple downlink dedicated carriers in the same time resources, a rule for determining which SRS carrier switching the UE shall perform among the multiple scheduled SRS carrier switching will be specifically described.

[0643] According to a second embodiment of this disclosure, when multiple SRS carrier handovers are scheduled to be performed simultaneously on multiple carriers within the same time resources, before specifically describing the method for determining which SRS carrier handover to perform based on priority, it is assumed that the DCI used to schedule multiple SRS carrier handovers to be performed simultaneously satisfies all timeline conditions used to determine whether the UE will perform an SRS carrier handover. Here, the timeline conditions refer to the guarantee time being greater than or equal to the sum of the following two: the time N2 required to decode the DCI and complete SRS transmission preparation before transmitting the SRS carrier handover first between overlapping uplink channels or other uplink channels (e.g., PUCCH / PUSCH / SRS) (based on the last received symbol of the PDCCH including the DCI), and the time required to tune the RF to perform the SRS carrier handover. (Here, It can be defined as considering the maximum of max{switchingTimeUL, switchingTimeDL} or all the values ​​of the above additional tuning times.

[0644] As specifically described in the first embodiment of this disclosure Figure 14 In the example shown, the base station can send multiple DCIs to the UE to schedule SRS carrier handover, and can schedule overlapping SRS carrier handovers in which multiple DCIs are transmitted in the same time resources. Unlike the first embodiment, which describes a method for simultaneously performing multiple overlapping SRS carrier handovers in the time domain based on UE capabilities, the second embodiment describes a method for determining the SRS carrier handover to be transmitted by the UE among multiple overlapping SRS carrier handovers according to a newly defined overlap rule.

[0645] Figure 17 Multiple scheduled SRS carrier switchings according to embodiments of the present disclosure are illustrated.

[0646] refer to Figure 17 Assume that CA is supported between multiple carriers c1_1 and c1_2 that only support downlink reception and carrier c2_1 that supports both uplink transmission and downlink reception, and that CA can be in-band CA or inter-band CA. Alternatively, similar to Figure 16 SRS are scheduled to overlap in the same time resources in each frequency band, and the RF link can transmit SRS by borrowing carriers that support both uplink and downlink in the same frequency band as the carrier. Here, it is assumed that the start or last symbols of DCI 1701 and 1711 received on the two carriers c1_1 and c1_2 are different from each other, and the UE transmits SRS 1702 scheduled by DCI 1701, which was received later and completed later, earlier than the UE transmits SRS 1712 scheduled by DCI 1711, which was received earlier and completed earlier. Figure 17 The UE shown may operate only one RF link 1721 for the corresponding situation, therefore the UE may not be able to simultaneously transmit two overlapping SRSs 1702 and 1712 in the time domain on two carriers c1_1 and c1_2. For example, after selectively performing one of the two RF tunings 1722 and 1723, only one of the two SRSs 1702 and 1712 may be transmitted. Figure 17 In such cases, the UE may consider one or a combination of the following additional overlap rules to select one SRS for transmission between the two SRSs 1702 and 1712: Additional Overlap Rule 1) The UE can determine the SRS carrier handover to be performed based on the reception completion time of the DCI that schedules the SRS carrier handover. When multiple SRS transmissions (i.e., SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol, the UE can perform an SRS carrier handover scheduled by the DCI in the PDCCH that was received earlier than the last symbol of the DCI that detected the SRS carrier handover among the multiple SRS transmissions (i.e., SRS carrier handovers). Furthermore, other overlapping SRS carrier handovers can be discarded. In this case, the UE can determine SRS transmission overlap even if the RF tuning times overlap, based on the SRS transmission time (including all RF tuning times before and after performing the SRS carrier handover). Figure 17 If SRS1 1702 and SRS2 1712 are scheduled to overlap, the UE can transmit SRS2 1712 scheduled by the second DCI format 1_1 1711 with the earlier reception completion time, and discard SRS1 1702 scheduled by the first DCI format 1_1 1701 with the later reception completion time, according to the additional overlap rule 1.

[0647] If SRS carrier handovers do not overlap in the time domain, the UE can perform non-overlapping SRS carrier handovers. In this case, considering the SRS transmission time, which includes all RF tuning times before and after the SRS carrier handover, the UE can determine that SRS transmissions do not overlap if the RF tuning times also do not overlap. For example, assuming three SRS carrier handovers overlap, SRS1 can overlap with SRS2, SRS2 can overlap with SRS3, and SRS3 can not overlap with SRS1. In this case, if SRS1 is transmitted and SRS2 is discarded according to Additional Overlap Rule 1, the UE can transmit SRS1 and simultaneously transmit SRS3.

[0648] In cases where multiple SRS transmissions (referring to SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol by applying another additional overlap rule 1, the UE can perform an SRS carrier handover scheduled by the DCI in the later PDCCH based on the last symbol received by the PDCCH that detects the SRS carrier handover in the DCI that scheduled the multiple SRS transmissions (referring to SRS carrier handovers). Furthermore, other overlapping SRS carrier handovers can be discarded. In this case, the UE can determine SRS transmission overlap even if the RF tuning times overlap, based on the SRS transmission time (including all RF tuning times before and after performing the SRS carrier handover). Figure 17 If SRS1 1702 and SRS2 1712 are scheduled to overlap, the UE can transmit SRS1 1702, scheduled by the first DCI format 1_1 1701 with the later receive completion time, according to Additional Overlap Rule 1, and discard SRS2 1712, scheduled by the second DCI format 1_1 1711 with the earlier receive completion time. Similarly, if the SRS carrier switching does not overlap in the time domain, the UE can transmit non-overlapping SRS carrier switching. In this case, based on the SRS transmission time, which includes all RF tuning times before and after the SRS carrier switching, the UE can determine that the SRS transmissions do not overlap if the RF tuning times also do not overlap.

[0649] Additional Overlap Rule 2) The UE can determine the SRS carrier handover to be transmitted based on the reception start time of the DCI that schedules the SRS carrier handover. In the case where multiple SRS transmissions (referring to SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol, the UE can perform the SRS carrier handover scheduled by the DCI in the earlier PDCCH, based on the first symbol of the PDCCH reception that detects the DCI that schedules the SRS carrier handover among the multiple SRS transmissions (referring to SRS carrier handovers). Furthermore, other overlapping SRS carrier handovers can be discarded. In this case, the UE can determine the SRS transmission overlap based on the SRS transmission time (including all RF tuning times before and after performing the SRS carrier handover), even if the RF tuning times overlap. Figure 17 If SRS1 1702 and SRS2 1712 are scheduled to overlap, the UE can transmit SRS2 1712 scheduled by the second DCI format 1_1 1711 with the earlier reception start time, and discard SRS1 1702 scheduled by the first DCI format 1_1 1701 with the later reception start time, according to the additional overlap rule 2.

[0650] If SRS carrier handovers do not overlap in the time domain, the UE can perform non-overlapping SRS carrier handovers. In this case, considering the SRS transmission time, which includes all RF tuning times before and after the SRS carrier handover, the UE can determine that SRS transmissions do not overlap if the RF tuning times also do not overlap. For example, assuming three SRS carrier handovers overlap, SRS1 can overlap with SRS2, SRS2 can overlap with SRS3, and SRS3 can not overlap with SRS1. In this case, if SRS1 is transmitted and SRS2 is discarded according to Additional Overlap Rule 2, the UE can transmit SRS1 and simultaneously transmit SRS3.

[0651] In cases where multiple SRS transmissions (referring to SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol by applying another additional overlap rule 2, the UE can perform an SRS carrier handover scheduled by the DCI in the later PDCCH based on the first symbol of the PDCCH reception that detects the DCI scheduling the SRS carrier handover among the multiple SRS transmissions (referring to SRS carrier handovers). Furthermore, other overlapping SRS carrier handovers can be discarded. In this case, the UE can determine SRS transmission overlap based on the SRS transmission time (including all RF tuning times before and after performing the SRS carrier handover), even if the RF tuning times overlap. Figure 17If SRS1 1702 and SRS2 1712 are scheduled to overlap, the UE can transmit SRS1 1702, scheduled by the first DCI format 1_1 1701 with the later reception start time, according to Additional Overlap Rule 2, and discard SRS2 1712, scheduled by the second DCI format 1_1 1711 with the earlier reception start time. Similarly, if the SRS carrier handovers do not overlap in the time domain, the UE can perform non-overlapping SRS carrier handovers. In this case, based on the SRS transmission time, which includes all RF tuning times before and after the SRS carrier handover, the UE can determine that the SRS transmissions do not overlap if the RF tuning times also do not overlap.

[0652] Additional Overlap Rule 3) The UE can perform the SRS carrier handover that initiates SRS transmission first among the scheduled SRS carrier handovers and discard other SRS carrier handovers. When multiple SRS transmissions (referring to SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol, the UE performs the SRS carrier handover that initiates SRS transmission first among the multiple SRS transmissions (referring to SRS carrier handovers). In addition, other overlapping SRS carrier handovers can be discarded. Based on the SRS transmission time (including all RF tuning times before and after performing the SRS carrier handover), the UE can determine SRS transmission overlap even if the RF tuning times overlap.

[0653] Additional Overlap Rule 4) The UE may execute the SRS carrier handover that initiates SRS transmission latest among the scheduled SRS carrier handovers and discard other SRS carrier handovers. When multiple SRS transmissions (referring to SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol, the UE executes the SRS carrier handover that initiates SRS transmission latest among the multiple SRS transmissions (referring to SRS carrier handovers). In addition, other overlapping SRS carrier handovers may be discarded. Based on the SRS transmission time (including all RF tuning times before and after executing the SRS carrier handover), the UE can determine SRS transmission overlap even if the RF tuning times overlap.

[0654] Additional Overlap Rule 5) The UE may execute the SRS carrier handover that completes SRS transmission first among the scheduled SRS carrier handovers and discard other SRS carrier handovers. When multiple SRS transmissions (referring to SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol, the UE executes the SRS carrier handover that completes SRS transmission first among the multiple SRS transmissions (referring to SRS carrier handovers). In addition, other overlapping SRS carrier handovers may be discarded. Based on the SRS transmission time (including all RF tuning times before and after executing the SRS carrier handover), the UE can determine SRS transmission overlap even if the RF tuning times overlap.

[0655] Additional Overlap Rule 6) The UE may execute the SRS carrier handover that is the latest to complete SRS transmission among the scheduled SRS carrier handovers and discard other SRS carrier handovers. When multiple SRS transmissions (referring to SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol, the UE executes the SRS carrier handover that is the latest to complete SRS transmission among the multiple SRS transmissions (referring to SRS carrier handovers). In addition, other overlapping SRS carrier handovers may be discarded. Based on the SRS transmission time (including all RF tuning times before and after executing the SRS carrier handover), the UE can determine SRS transmission overlap even if the RF tuning times overlap.

[0656] Additional Overlap Rule 7) The UE can determine the SRS carrier handover to be transmitted based on the serving cell index of the serving cell to which the SRS carrier handover is scheduled, the carrier index of the carrier, etc. When multiple SRS transmissions (referring to SRS carrier handovers) scheduled for different carriers (or different frequency bands or serving cells) overlap within the same symbol, the UE can perform the SRS carrier handover scheduled for the serving cell with the smallest index value (or the carrier with the smallest carrier index) among the multiple SRS transmissions (referring to SRS carrier handovers). In addition, other overlapping SRS carrier handovers can be discarded. Based on the SRS transmission time (including all RF tuning times before and after performing the SRS carrier handover), the UE can determine the SRS transmission overlap even if the RF tuning times overlap.

[0657] Additional Overlap Rule 8) The UE may not expect to perform multiple SRS carrier handovers on the same serving cell or the same carrier. In this case, the base station must schedule SRS carrier handovers for the UE so that multiple SRS carrier handovers that overlap in time on a serving cell or a carrier (including all RF tuning times before and after the SRS carrier handover) do not overlap.

[0658] When determining the SRS carrier handover to be performed by the UE based on the above additional overlap rules, if the SRS carrier handover to be performed cannot be determined by one additional overlap rule, the UE can determine the SRS carrier handover to be performed by considering other additional overlap rules. [...

Claims

1. A method performed by a user equipment (UE) in a communication system, the method comprising: Capability information associated with the switching of the Synchronization Detection Reference Signal (SRS) carrier is transmitted to the base station; The base station receives downlink control information (DCI) format, wherein the DCI format schedules SRS in component carriers (CC) for SRS carrier handover, wherein the capability information indicates support for the synchronous SRS carrier handover, and the SRSs overlap in time; and At least one of the scheduled SRSs is transmitted to the base station for SRS carrier switching.

2. The method as described in claim 1, in, Based on the capability information, including first information indicating support for synchronous SRS carrier handover for in-band carrier aggregation (CA) and the CC simultaneously transmitting the scheduled SRS for SRS carrier handover within the CC based on the in-band CA, and Wherein, the first information indicates at least one of the following: The RF tuning time required for SRS carrier switching, or Does the synchronous SRS carrier switching for in-band CA support the use of partially overlapping or fully overlapping SRS? 3. The method as described in claim 2, in, Based on the capability information, including second information indicating support for synchronous SRS carrier handover for inter-band carrier aggregation (CA), and the CC simultaneously transmitting the scheduled SRS for SRS carrier handover within the CC based on the inter-band CA, the capability information is as follows: Wherein, the second information indicates at least one of the following: Frequency bands affected by SRS carrier switching The RF tuning time required for SRS carrier switching, or Does it support the switching of the synchronous SRS carrier for inter-band CA to be used for partially overlapping SRS or fully overlapping SRS? 4. The method as described in claim 1, wherein radio resource control (RRC) parameters for enabling the synchronous SRS carrier handover are received from the base station.

5. The method of claim 1, wherein, Based on the capability information, which does not indicate support for the synchronous SRS carrier switching, the SRS used for SRS carrier switching do not overlap in time.

6. A method performed by a base station in a communication system, the method comprising: Receive capability information associated with the switching of the Synchronization Detection Reference Signal (SRS) carrier from the User Equipment (UE); The downlink control information (DCI) format is transmitted to the UE, wherein the DCI format schedules SRS in component carriers (CC) for SRS carrier handover, wherein the capability information indicates support for the synchronous SRS carrier handover, and the SRSs overlap in time; and The UE receives at least one of the scheduled SRSs for SRS carrier switching.

7. The method as described in claim 6, in, Based on the capability information, including first information indicating support for synchronous SRS carrier handover for in-band carrier aggregation (CA), and the CC simultaneously receiving the scheduled SRS for SRS carrier handover in the CC based on the in-band CA, and Wherein, the first information indicates at least one of the following: The RF tuning time required for SRS carrier switching, or Does the synchronous SRS carrier switching for in-band CA support the use of partially overlapping or fully overlapping SRS? 8. The method as described in claim 6, in, Based on the capability information, including second information indicating support for synchronous SRS carrier handover for inter-band carrier aggregation (CA), and the CC simultaneously receiving the scheduled SRS for SRS carrier handover based on the inter-band CA, the CC also receives the scheduled SRS for SRS carrier handover based on the inter-band CA. Wherein, the second information indicates at least one of the following: Frequency bands affected by SRS carrier switching The RF tuning time required for SRS carrier switching, or Does it support the switching of the synchronous SRS carrier for inter-band CA to be used for partially overlapping SRS or fully overlapping SRS? 9. The method of claim 6, further comprising: The Radio Resource Control (RRC) parameters for enabling the Synchronous SRS Carrier Switching are transmitted to the UE.

10. The method of claim 6, wherein, Based on the capability information, which does not indicate support for the synchronous SRS carrier switching, the SRS used for SRS carrier switching do not overlap in time.

11. A user equipment (UE) in a communication system, the UE comprising: transceiver; as well as At least one processor is configured to: The ability to transmit capability information associated with the switching of the Synchronization Detection Reference Signal (SRS) carrier to the base station. The base station receives downlink control information (DCI) in DCI format, wherein the DCI format schedules SRS in component carriers (CC) for SRS carrier handover, wherein the capability information indicates support for the synchronous SRS carrier handover, and the SRSs overlap in time. At least one of the scheduled SRSs is transmitted to the base station for SRS carrier switching.

12. The UE as described in claim 11, in, Based on the capability information, including first information indicating support for synchronous SRS carrier handover for in-band carrier aggregation (CA) and the CC simultaneously transmitting the scheduled SRS for SRS carrier handover within the CC based on the in-band CA, and Wherein, the first information indicates at least one of the following: The radio frequency (RF) tuning time required for SRS carrier switching, or Does the synchronous SRS carrier switching for in-band CA support the use of partially overlapping or fully overlapping SRS? 13. The UE as described in claim 11, in, Based on the capability information, including second information indicating support for synchronous SRS carrier handover for inter-band carrier aggregation (CA), and the CC simultaneously transmitting the scheduled SRS for SRS carrier handover within the CC based on the inter-band CA, the capability information is as follows: Wherein, the second information indicates at least one of the following: Frequency bands affected by SRS carrier switching The RF tuning time required for SRS carrier switching, or Does it support the switching of the synchronous SRS carrier for inter-band CA to be used for partially overlapping SRS or fully overlapping SRS? 14. The UE as claimed in claim 11, wherein, The at least one processor is further configured to receive Radio Resource Control (RRC) parameters from the base station that enable the Synchronous SRS carrier handover.

15. A base station in a communication system, the base station comprising: transceiver; as well as At least one processor is configured to: Receive capability information associated with the Synchronization Detection Reference Signal (SRS) carrier handover from the User Equipment (UE). Downlink Control Information (DCI) format is transmitted to the UE, wherein the DCI format schedules SRS in component carrier CC for SRS carrier handover, wherein the capability information indicates support for the synchronous SRS carrier handover, and the SRS overlap in time. The UE receives at least one of the scheduled SRSs for SRS carrier switching.

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